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MPA Literature Summaries

Addessi, L. 1994. Human disturbance and long-term changes on a rocky intertidal community. Ecological Applications. 4:768-797.

The effects of human recreational activities on a rocky intertidal habitat on the coast of San Diego, California, USA were investigated. Organisms susceptible to collection for food, bait, or aquaria were identified and served as key species for the study of biota disturbance. This study examined three major aspects: (1) Distribution and activities of people along the shoreline were documented. (2) Distribution and density of echinoderms and molluscs inhabiting the cryptic underrock surface were sampled along an identified gradient of disturbance. (3) Densities of conspicuous organisms inhabiting the underrock surface at the most disturbed location detected in the spring of 1971 were compared with those detected in the spring of 1991.

Surveys of human activity made during weekends with low tides exposing most of the intertidal zone (below 0 MLLW) during the daylight hours between December 1990 and August 1991 showed a definite pattern. People concentrated in an area with a 200 m radius centered on the primary accesses; areas farther from these points were less visited. The study site stood along a gradient of human disturbance, and the sampling of organisms along this indicated a gradient of biota disturbance as well. The density of all species was reduced in the more heavily visited intertidal area. The underrock community at the most heavily visited location changed substantially from spring 1971 to spring 1991. The density of most of the macroorganisms decreased between the two dates, with the exception of the density of small gastropods, which increased.

Even if more long-term studies are needed for determining the actual status of communities under the influence of human disturbance, the combination of spatial and longterm studies shows the importance of setting better policy and establishing more effective reserves in order to enhance and maintain species diversity and density.

Community structure; human disturbance; reserves; rocky intertidal

Agardy, T. (2000). Information needs for marine protected areas: scientific and societal. Bulletin of Marine Science 66(3): 875-888.

Marine protected areas are increasingly being used to protect biologically rich habitats, resolve user conflicts, and help restore overexploited stocks and degraded areas. The upsurge in the use of the tool has arisen in part because fisheries managers are now looking to reserves to complement conventional fisheries management techniques. In the United States, the legislative requirement to identify and protect essential fish habitat for managed fisheries species has contributed to the debate over and use of marine protected areas in all their various forms. Information needed to design and implement effective marine protected areas is usually drawn from the fields of fish population dynamics, oceanography, community ecology, and organismal biology, but because the placement, design, and management of marine protected areas are all related to the intended goals, the most crucial information is that about the specific objectives the protected area is designed to achieve. This information is ultimately societal, not scientific. After the specific objectives are elaborated, conservation biology and other sciences can be harnessed to help identify what needs to be protected and in what manner, leading to optimally effective marine protected areas.

mpa, legislative requirement, fisheries management

Agardy, T., P. Bridgewater, M.P. Crosby, J. Day, P.K. Dayton, R. Kenchington, D. Laffoley, P. McConney, P.A. Murray, J.E. Parks, and L. Peau. 2003. Dangerous targets? Unresolved issues and ideological clashes around marine protected areas. Aquatic Conserv: Mar. Freshw. Ecosyst.

  1. While conservationists, resource managers, scientists and coastal planners have recognized the broad applicability of marine protected areas (MPAs), they are often implemented without a firm understanding of the conservation science } both ecological and socio-economic } underlying marine protection. The rush to implement MPAs has set the stage for paradoxical differences of opinions in the marine conservation community.
  2. The enthusiastic prescription of simplistic solutions to marine conservation problems risks polarization of interests and ultimately threatens bona fide progress in marine conservation. The blanket assignment and advocacy of empirically unsubstantiated rules of thumb in marine protection creates potentially dangerous targets for conservation science.
  3. Clarity of definition, systematic testing of assumptions, and adaptive application of diverse MPA management approaches are needed so that the appropriate mix of various management tools can be utilized, depending upon specific goals and conditions. Scientists have a professional and ethical duty to map out those paths that are most likely to lead to improved resource management and understanding of the natural world, including the human element, whether or not they are convenient, politically correct or publicly magnetic.
  4. The use of MPAs as a vehicle for promoting long-term conservation and sustainable use of marine biodiversity is in need of focus, and both philosophical and applied tune ups. A new paradigm arising out of integrated, multi-disciplinary science, management and education/outreach efforts must be adopted to help promote flexible, diverse and effective MPA management strategies. Given scientific uncertainties, MPAs should be designed so one can learn from their application and adjust their management strategies as needed, in the true spirit of adaptive management.
  5. It is critical for the conservation community to examine why honest differences of opinion regarding MPAs have emerged, and recognize that inflexible attitudes and positions are potentially dangerous. We therefore discuss several questions } heretofore taken as implicit assumptions: (a) what are MPAs, (b) what purpose do MPAs serve, (c) are no-take MPAs the only legitimate MPAs, (d) should a single closed area target be set for all MPAs, and (e) how should policymakers and conservation communities deal with scientific uncertainty?

Airame, S., J.E. Dugan, K.D. Lafferty, H. Leslie, D.A. McArdle, and R.R. Warner. 2003. Applying Ecological Criteria to Marine Reserve Design: A Case Study from the California Channel Islands. Ecological Applications 13(1) Supplement: S170-S184.

Using ecological criteria as a theoretical framework, we describe the steps involved in designing a network of marine reserves for conservation and fisheries management. Although we describe the case study of the Channel Islands, the approach to marine reserve design may be effective in other regions where traditional management alone does not sustain marine resources. A group of agencies, organizations, and individuals established clear goals for marine reserves in the Channel Islands, including conservation of ecosystem biodiversity, sustainable fisheries, economic viability, natural and cultural heritage, and education. Given the constraints of risk management, experimental design, monitoring, and enforcement, scientists recommended at least one, but no more than four, reserves in each biogeographic region. In general, the percentage of an area to be included in a reserve network depends on the goals. In the Channel Islands, after consideration of both conservation goals and the risk from human threats and natural catastrophes, scientists recommended reserving an area of 30-50% of all representative habitats in each biogeographic region. For most species of concern, except pinnipeds and seabirds, information about distributions, dispersal, and population growth was limited. As an alternative to species distribution information, suitable habitats for species of concern were used to locate potential reserve sites. We used a simulated annealing algorithm to identify potential reserve network scenarios that would represent all habitats within the smallest area possible. The analysis produced an array of potential reserve network scenarios that all met the established goals.

Allison, G.W., S.D. Gaines, J. Lubencho, and H.P. Possingham. 2003. Ensuring Persistence of Marine Reserves: Catastrophes Require Adopting an Insurance Factor. Ecological Applications 13(1) Supplement: S8-S24.

When viewed across long temporal and large spatial scales, severe disturbances in marine ecosystems are not uncommon. Events such as hurricanes, oil spills, disease outbreaks, hypoxic events, harmful algal blooms, and coral bleaching can cause massive mortality and dramatic habitat effects on local or even regional scales. Although designers of marine reserves might assume low risk from such events over the short term, catastrophes are quite probable over the long term and must be considered for successful implementation of reserves. A simple way to increase performance of a reserve network is to incorporate into the reserve design a mechanism for calculating how much additional area would be required to buffer the reserve against effects of catastrophes. In this paper, we develop a method to determine this ''insurance factor'': a multiplier to calculate the additional reserve area necessary to ensure that functional goals of reserves will be met within a given ''catastrophe regime.'' We document and analyze the characteristics of two relatively well-studied types of disturbances: oil spills and hurricanes.We examine historical data to characterize catastrophe regimes within which reserves must function and use these regimes to illustrate the application of the insurance factor. This tool can be applied to any reserve design for which goals are defined by a quantifiable measure, such as a fraction of shoreline, that is necessary to accomplish a particular function. In the absence of such quantitative measures, the concept of additional area as insurance against catastrophes may still be useful.

Allison, G. W., J. Lubchenco and M. H. Carr. 1998. Marine Reserves are Necessary but not Sufficient for Marine Conservation. Ecological Applications. 8:S79-S92.

The intensity of human pressure on marine systems has led to a push for stronger marine conservation efforts. Recently, marine reserves have become one highly advocated form of marine conservation, and the number of newly designated reserves has increased dramatically. Reserves will be essential for conservation efforts because they can provide unique protection for critical areas, they can provide a spatial escape for intensely exploited species, and they can potentially act as buffers against some management miscalculations and unforeseen or unusual conditions. Reserve design and effectiveness can be dramatically improved by better use of existing scientific understanding. Reserves are insufficient protection alone, however, because they are not isolated from all critical impacts. Communities residing within marine reserves are strongly influenced by the highly variable conditions of the water masses that continuously flow through them. To a much greater degree than in terrestrial systems, the scales of fundamental processes, such as population replenishment, are often much larger than reserves can encompass. Further, they offer no protection from some important threats, such as contamination by chemicals. Therefore, without adequate protection of species and ecosystems outside reserves, effectiveness of reserves will be severely compromised. We outline conditions under which reserves are likely to be effective, provide some guidelines for increasing their conservation potential, and suggest some research priorities to fill critical information gaps. We strongly support vastly increasing the number and size of marine reserves; at the same time, strong conservation efforts outside reserves must complement this effort. To date, most reserve design and site selection have involved little scientific justification. They must begin to do so to increase the likelihood of attaining conservation objectives.

Biodiversity; harvest refugia; marine parks; marine protected areas; open populations; population replenishment; Reserve design

Anderson, C. N. K., C.-h. Hsieh, S. A. Sandin, R. Hewitt, A. Hollowed, J. Beddington, R. M. May, G. Sugihara. (2008). Why fishing magnifies fluctuations in fish abundance. Nature 452: 835-839.

It is now clear that fished populations can fluctuate more than unharvested stocks. However, it is not clear why. Here we distinguish among three major competing mechanisms for this phenomenon, by using the 50-year California Cooperative Oceanic Fisheries Investigations (CalCOFI) larval fish record. First, variable fishing pressure directly increases variability in exploited populations. Second, commercial fishing can decrease the average body size and age of a stock, causing the truncated population to track environmental fluctuations directly. Third, age-truncated or juvenescent populations have increasingly unstable population dynamics because of changing demographic parameters such as intrinsic growth rates. We find no evidence for the first hypothesis, limited evidence for the second and strong evidence for the third. Therefore, in California Current fisheries, increased temporal variability in the population does not arise from variable exploitation, nor does it reflect direct environmental tracking. More fundamentally, it arises from increased instability in dynamics. This finding has implications for resource management as an empirical example of how selective harvesting can alter the basic dynamics of exploited populations, and lead to unstable booms and busts that can precede systematic declines in stock levels.

fished populations, flucutations, systematic decline

Angulo-Valdes, J. A. and B. G. Hatcher. (2009). A new typology of benefits derived from marine protected areas. Marine Policy.

Global decline of marine resources has triggered a worldwide demand for changing the way ocean resources are managed. Ecosystem based management approaches have emerged using marine protected areas (MPA) as the main tool. Several classifications of marine protected areas benefits have been made, but all have focused only on the benefits to humans, neglecting many important benefits accrued to nature. This paper presents a new comprehensive classification of MPA benefits that will provide scientists and managers with an inclusive framework to accurately identify and account for all possible benefits derived from MPAs. The paper also analyses the methods available for valuing these benefits. A total of 99 benefits were identified within nine main categories: fishery, on-fishery, management, education/research, cultural, process, ecosystem, population and species benefits. These categories are arranged in two main divisions (direct and indirect benefits),which, at the same time, fall within the realms of benefits to humans and to nature.

MPA benefit, eco-system, framework

Apostolaki, P., E.J. Milner-Gulland, M.K. McAllister, and G.P. Kirkwood. 2002. Modelling the effects of establishing a marine reserve for mobile fish species. Canadian Journal of Fisheries and Aquatic Sciences. 59: 405-415

We present a model of the effects of a marine reserve on spawning stock biomass (SSB) and short- and long-term yield for a size-structured species that exhibits seasonal movements. The model considers the effects of protecting nursery and (or) spawning grounds under a range of fishing mortalities and fish mobility rates. We consider two extremes of effort redistribution following reserve establishment and analyze the effects of a reserve when the fishery targets either mature or immature fish. We apply the model to the Mediterranean hake (Merluccius merluccius) and show that a marine reserve could be highly beneficial for this species. We demonstrate benefits from reserves not just for overexploited stocks of low-mobility species, but also (to a lesser extent) for underexploited stocks and high mobility species. Greatly increased resilience to overfishing is also found in the majority of cases. We show that a reserve provides benefits additional to those obtained from simple effort control. Benefits from reserves depend to a major extent on the amount of effort redistribution following reserve establishment and on fishing selectivity; hence, these factors should be key components of any evaluation of reserve effectiveness.

Armstrong, C. W. and A. Skonhoft. 2006. Marine reserves: A bio-economic model with asymmetric density dependent migration. Ecological Economics. 57:466-476.

A static bioeconomic model of a marine reserve allowing asymmetric density  ependent migration between the reserve and the fishable area is introduced. This opens for habitat or ecosystem differences allowing different fish densities within and outside a reserve, not described in earlier studies. Four management scenarios are studied; (a) maximum harvest, (b) maximum current profit, (c) open access and (d) maximum sustainable yield (MSY) in the reserve. These are all analysed within the Induced Sustainable Yield Function (ISYF), giving the relationship between the fish abundance inside the reserve and the harvesting taking place outside. A numerical analysis shows that management focused on ensuring MSY within the reserve under the assumption of symmetric migration may be negative from an economic point of view, when the area outside the reserve is detrimental compared to the reserve. Furthermore, choice of management option may also have negative consequences for long run resource use if it is incorrectly assumed that density dependent migration is symmetric. The analysis also shows that the optimal area to close, either a more or a less attractive ecosystem for the resource in question, may differ depending on the management goal.

Bioeconomics; Marine reserves; Migration; Management

Babcock, R. C., N. T. Shears, A. C. Alcala, N. S. Barrett, G. J. Edgar, K. D. Lafferty, T. R. McClanahan, and G. R. Russ. (2010).Decadal trends in marine reserves reveal differential rates of change in direct and indirect effects. PNAS Early Edition: 1-6.

Decadal-scale observations of marine reserves suggest that indirect effects on taxa that occur through cascading trophic interactions take longer to develop than direct effects on target species. Combining and analyzing a unique set of long-term time series of ecologic data in and out of fisheries closures from disparate regions, we found that the time to initial detection of direct effects on target species (±SE) was 5.13 ± 1.9 years, whereas initial detection of indirect effects on other taxa, which were often trait mediated, took significantly longer (13.1 ± 2.0 years). Most target species showed initial direct effects, but their trajectories over time were highly variable. Many target species continued to increase, some leveled off, and others decreased. Decreases were due to natural fluctuations, fishing impacts from outside reserves, or indirect effects from target species at higher trophic levels. The average duration of stable periods for direct effects was 6.2 ± 1.2 years, even in studies of more than 15 years. For indirect effects, stable periods averaged 9.1 ± 1.6 years, although this was not significantly different from direct effects. Populations of directly targeted species were more stable in reserves than in fished areas, suggesting increased ecologic resilience. This is an important benefit of marine reserves with respect to their function as a tool for conservation and restoration.

fishing effects, interactions, time lag, trophic cascade, marine protected area

Babcock, R. C., E. K. Pikitch, M. K. McAllister, P. Apostolaki and C. Santora. 2005. A perspective on the use of spatialized indicators for ecosystem-based fishery management through spatial zoning. ICES Journal of Marine Science. 62:469-476.

Although much work has been done developing system-level indicators for ecosystembased fishery management (EBFM), few of those proposed include a spatial component. Even in single-species management, time and area closures have been applied without a clear understanding of what their effect might be on identifying overfishing thresholds and other reference points. For EBFM, spatial zoning of the marine environment, including no take marine reserves and areas where destructive fishing gears are prohibited, may become a prime management tool. Therefore, indicators of the effectiveness of spatial management will be required, along with an understanding of how indicators related to other objectives will be influenced. We review single-species models that have been used to model spatial zoning, including potential bias in assessment and current work on effort reallocation after area closure, as well as available ecosystem-based models and metrics and how they might account for spatial management. Metrics that can be derived from explicitly spatial approaches such as GIS-based ecosystem and fishery evaluations are also discussed.

CPUE; ecosystems; fishery management; GIS; spatial modelling

Babcock, R. C., S. Kelly, N. T. Shears, J. W. Walker and T. J. Willis. 1999. Changes in community structure in temperate marine reserves. Marine Ecology Progress Series. 189:125-134.

No-take' marine reserves provide a valuable tool for managing marine resources as well as for providing relatively undisturbed habitat with which to assess modifications to ecosystems. We studied 2 marine reserves in northeastern New Zealand, the Leigh Marine Reserve (established 1975) and Tawharanui Marine Park (established 1982) in order to assess whether changes in protected predator populations had resulted in other indirect changes to grazers and consequently to algal abundance. Estimates of abundance of the most common demersal predatory fish Pagrus auratus indicated that adults of this species (i.e. large enough to prey upon urchins) were at least 5.75 and 8.70 times more abundant inside reserves than in adjacent unprotected areas. Overall, P auratus were also much larger inside reserves with mean total lengths of 316 mm compared with 186 mm in fished areas. The spiny lobster Jasus edwardsii displayed similar trends, and was approximately 1.6 to 3.7 times more abundant inside the reserves than outside. Lobsters within the reserves had a mean carapace length of 109.9 mm, compared with 93.5 mm outside the reserves. In one of the reserves, densities of the sea urchin Evechinus chloroticus had declined from 4.9 to 1.4 m-2 since 1978 in areas formerly dominated by it. Consequently, kelp forests were more extensive in 1998 than they were at the time of reserve creation. Urchin-dominated barrens occupied only 14 % of available reef substratum in reserves as opposed to 40"4 in unprotected areas. These changes in community structure, which have persisted since at least 1994, demonstrate not only higher trophic complexity than anticipated in Australasian ecosystems but also increased primary and secondary productivity in marine reserves as a consequence of protection. Trends inside reserves indicate large-scale reduction of benthic primary production as an indirect result of fishing activity in unprotected areas.

Marine reserves; Habitat change; Trophic structure - Fishing effects; Urchins; Kelp; Fish; Spiny lobsters

Ban, N. C. 2009. Minimum data requirements for designing a set of marine protected areas, using commonly available abiotic and biotic datasets. Biodiversity and Conservation. 18:1829-1845.

Marine protected areas (MPAs) can be an effective tool for marine biodiversity conservation, yet decision-makers usually have limited and biased datasets with which to make decisions about where to locate MPAs. Using commonly available abiotic and biotic datasets, I asked how many datasets are necessary to achieve robust patterns of conservation importance. I applied a decision support tool for marine protected area design in two regions of British Columbia, Canada, and sequentially excluded the datasets with the most limited geographic distribution. I found that the reserve selection method was robust to some missing datasets. The removal of up to 15 of the most geographically limited datasets did not significantly change the geographic patterns of the importance of areas for conservation. Indeed, including abiotic datasets plus at least 12 biotic datasets resulted in a patial pattern similar to including all available biotic datasets. It was best to combine abiotic and biotic datasets in order to ensure habitats and species were represented. Patterns of clustering differed according to whether I used one set alone or both combined. Biotic datasets served as better surrogates for abiotic datasets than vice versa, and both represented more biodiversity features than randomly selected reserves. These results should provide encouragement to decision-makers engaged in MPA planning with limited spatial data.

Biodiversity surrogates; Data limitations; Marine conservation; Marine reserves; Marxan; Selection algorithm; Systematic conservation planning

Banks, S. A. and G. A. Skilleter. 2010.Implementing marine reserve networks: A comparison of approaches in New South Wales (Australia) and New Zealand Marine Policy. 34:197-207.

Marine reserve networks are an essential and effective tool for conserving marine biodiversity. They also have an important role in the governance of oceans and the sustainable management of marine resources. The translation of marine reserve network theory into practice is a challenge for conservation practitioners. Barriers to implementing marine reserves include varying levels of political will and agency support and leadership, poorly coordinated marine conservation policy, inconsistencies with the use of legislation, polarised views and opposition from some stakeholders, and difficulties with defining and mapping conservation features. The future success of marine reserve network implementation will become increasingly dependent on: increasing political commitment and agency leadership; greater involvement and collaboration with stakeholders; and the provision of resources to define and map conservation features. Key elements of translating marine reserve theory into implementation of a network of marine reserves are discussed based on approaches used successfully in New Zealand and New South Wales (Australia).

Marine conservation planning; Marine reserves; Reserve networks; Conservation policy

Barrett, N. S., G. J. Edgar, C. D. Buxton and M. Haddon. 2007. Changes in fish assemblages following 10 years of protection in Tasmanian marine protected areas. Journal of Experimental Marine Biology and Ecology. 345:141-157.

Most studies examining effects of marine protected areas (MPAs) on fish assemblages are potentially confounded, either because they are once off comparisons between fished and unfished locations, or because they are snapshot studies over a fixed period. Here we compare long-term changes within fully protected Tasmanian marine reserves with changes at external reference sites on an annual basis over the first ten years of protection. The results highlight the importance of long-term datasets for differentiating changes occurring over differing time scales. Notable results include a statistically significant increase in abundance of Latridopsis forsteri and large fish (N300 mm) when examined across all reserves relative to controls, and a 10-fold increase in the abundance of large fish and a doubling of per site species richness of large fish within the Tinderbox Marine Reserve relative to controls. Short-term resident species that recruit sporadically show very different patterns in reserves compared to those that recruit regularly and have long-term age-class storage. While several recent reviews have suggested size of MPAs and duration of protection has little influence on the extent of recovery, our results suggest this is not the case and that responses can be slow, complex and species-specific. The extent of localised fishing pressure appeared to have a substantial influence on the degree of change detected, potentially confounding meta-analyses of recovery rates in MPAs if overlooked as a relevant parameter.

Effects of fishing; Long-term analysis; Marine reserve; Reserve size

Barrett, N. S., C. D. Buxton and G. J. Edgar. 2009. Changes in invertebrate and macroalgal populations in Tasmanian marine reserves in the decade following protection. Journal of Experimental Marine Biology and Ecology. 370:10-119.

Densities of macrobenthic invertebrates and macro-algae in four Tasmanian 'no-take' marine protected areas (MPAs) were monitored annually for 10 years following MPA establishment, with changes compared to those at external (fished) reference locations. Fishing substantially influenced the population characteristics of many species, including altering the mean size and abundance of rock lobsters and the abundance of prey species such as urchins and abalone. Strong declines in abundances of purple urchins and abalone within the largest MPA at Maria Island indicate likely indirect effects related to protection of predators from fishing. The two smallest MPAs (ca. 1 km coastal span) generated few detectable changes. Our results affirm the importance of long-term monitoring and the value of MPAs, when sufficiently large, as reference areas for determining and understanding ecosystem effects of fishing in the absence of historical baseline data.

Abalone; Effects of fishing; Marine protected area; Reserve size; Rock lobster; Sea urchins

Baskett, M. L., F. Micheli and S. A. Levin. 2007. Designing marine reserves for interacting species: Insights from theory. Biological Conservation. 137:163-179.

The primary goals of marine reserves include protecting biodiversity and ecosystem structure. Therefore, a multispecies approach to designing and monitoring reserve networks is necessary. To gain insight into how the interactions between species in marine communities may affect reserve design, we synthesize marine reserve community models and community models with habitat destruction and fragmentation, and we develop new extensions of existing models. This synthesis highlights the potential for species interactions to alter reserve design criteria; in particular, accounting for species interactions often leads to an increase in reserve size necessary to protect populations. Accounting for species interactions also indicates the need to base reserve design and monitoring on a variety of species, especially long-distance dispersers, inferior colonizers, and specialists. Finally, the new model extensions highlight how, given dispersal, source populations outside reserves as well as increases in fished populations after reserve establishment may negatively affect reserve populations of competitors or prey. Therefore, multispecies harvest dynamics outside reserves and before reserve establishment are critical to determining the appropriate reserve size, spacing, and expectations after establishment. These models highlight the importance of species interactions to reserve design and provide guidelines for how this complexity can begin to be incorporated into conservation planning.

Marine protected areas; Habitat loss; Predation; Competition; Mutualism; Community models

Becker, B. J., L. A. Levin, F. J. Fodrie and P. A. McMillan. 2007. Complex larval connectivity patterns among marine invertebrate populations. Proceedings of the National Academy of Sciences. 104:3267-3272.

Based on the belief that marine larvae, which can spend days to months in the planktonic stage, could be transported considerable distances by ocean currents, it has long been assumed that populations of coastal species with a planktonic larval stage are demographically open and highly ‘‘connected.’’ Such assumptions about the connectivity of coastal populations govern approaches to managing marine resources and shape our fundamental understanding of population dynamics and evolution, yet are rarely tested directly due to the small size and high mortality of marine larvae in a physically complex environment. Here, we document a successful application of elemental fingerprinting as a tracking tool to determine sources of settled invertebrates and show that coastal mussel larvae, previously thought to be highly dispersed, can be retained within 20–30 km of their natal origin. We compare two closely related and co-occurring species, Mytilus californianus and Mytilus galloprovincialis, and determine that, despite expected similarities, they exhibit substantially different connectivity patterns. Our use of an in situ larval culturing technique overcomes the previous challenge of applying microchemical tracking methods to species with completely planktonic development. The exchange of larvae and resulting connectivities among marine populations have fundamental consequences for the evolution and ecology of species and for the management of coastal resources.

Elemental fingerprinting; in situ larval culturing; larval retention; larval transport; Mytilus

Beldade, R., R. Borges, and E. J. Gonçalves. (2006). Depth distribution of nearshore temperate fish larval assemblages near rocky substrates. Journal of Plankton Research 28(11): 1003-1013.

In this study, we compare the composition, abundance and structure of a temperate fish larval assemblage at different depth intervals (0–4, 4–8 and 8–12 m) in the extreme nearshore environment. We used a plankton net attached to an underwater scooter to sample in close proximity to the rocky substrate (<50 cm). A total of 868 larvae from 27 taxa in 13 families were caught. The majority of larvae belonged to benthic reef-associated species (Blenniidae, Gobiidae, Gobiesocidae and Tripterygiidae), the four most abundant comprising 76% of the total larvae caught. A non-metric multidimensional scaling analysis (MDS) showed that there was a single multispecific larval patch near the substrate in the extreme nearshore up to 12 m depth. Nonetheless, distinct larval abundances were found in this relatively small depth range, with the majority of species being more abundant at the deepest interval, particularly Pomatoschistus pictus and Gobius xanthocephalus. Tripterygion delaisi was an exception being more abundant at the shallowest depth as young larvae. The density of pre-flexion larvae was not significantly different across depth intervals, but post-flexion larval density increased with depth. The full size range (from hatching to settlement) of P. pictus was present at the extreme nearshore. The innovative sampling technique used here revealed high densities of larvae close to the bottom, and depth was found to be an important factor influencing the distribution of several taxa and ontogenetic stages. The nearshore component of coastal fish larval assemblages near rocky substrates has been poorly studied, and our results suggest that the high densities of larvae found to aggregate in these environments must be taken into account when studying distribution and functional aspects of these assemblages.

Temperate, fish larval assemblage, reef-associated species

Bell, J. 1983. Effects of depth and marine reserve fishing restrictions on the structure of a rocky reef fish assemblage in the North-Western Mediterranean Sea. The Journal of Applied Ecology. 20:357-369.

  1. A visual scuba diving census, in which abundance and size class structure of conspicuous fish species were determined, was used to assess the effects of depth and marine reserve fishing restrictions on the structure of a Mediterranean rocky reef fish assemblage by comparing communities at sites from two depth ranges inside and outside a marine reserve.
  2. The total assemblage had thirty-five conspicuous species and was dominated by Labridae (thirteen spp.) and Sparidae (nine spp.).
  3. Mean species richness (number of species) and diversity (Shannon) did not differ significantly between sites.
  4. Ordination of abundance data showed that occurrence and relative abundance of species was affected by depth (deep samples separated completely from shallow samples) and marine reserve status (samples from the marine reserve were significantly separated from those taken at the same depth outside the reserve).
  5. Samples from the same depth were similar, because the majority of species showed a preference for either deep or shallow areas. The known biology of several species indicated that feeding requirements may be responsible for depth preferences.
  6. Samples from reserve sites had signficantly higher densities of fish species sought after and/or vulnerable to local fishing methods, than those from non-reserve sites of similar depth.
  7. Size frequency distributions of vulnerable species at reserve sites generally had a larger modal size class than distributions from non-reserve sites.
  8. The data suggest that reduced fishing pressure in the reserve has provided effective protection for species vulnerable to fishing.

Bellefleur, D., P. Lee, R. A. Ronconi. (2007).The impact of recreational boat traffic on Marbled Murrelets (Brachyramphus marmoratus). Journal of Environmental Manangement: 1-8.

This study evaluated the impact of small boat traffic on reaction distances of Marbled Murrelets (Brachyramphus marmoratus), in the marine waters of Pacific Rim National Park Reserve, British Columbia, Canada. Observers on moving boats recorded the minimum distance the boat came to murrelets on the water, and any disturbance reaction (fly, dive, no reaction). Out of the 7500 interactions 11.7% flew, 30.8% dove and 58.1% exhibited no flushing reaction. Using a product-limit analysis, we developed curves for the proportion of Marbled Murrelets flushing (dive or flight) as a function of reaction distance. Overall, the majority of Marbled Murrelets waited until boats were within 40 m before reacting, with 25% of the population reacting at 29.2 m. A stepwise Cox regression indicated that age, boat speed, and boat density (loaded in that order), significantly affected flushing response. More juveniles flushed than adults (70.1 versus 51.7%), but at closer distances. Faster boats caused a greater proportion of birds to flush, and at further distances (25% of birds flushed at 40 m at speeds >29 kph versus 28 m at speeds <12 kph). A stepwise logistic regression on diving and flight responses indicated that birds tended to fly completely out of feeding areas at the approach of boats travelling >28.8 kph and later in the season (July and August). Other secondary variables included; boat density and time of day. Discussion focused on possible management actions such as the application of speed limits, set back distances, and exclusion of boat traffic to protect Marbled Murrelets.

Species at Risk Act; SARA; Boat disturbance; Bird disturbance; Seabirds; Protected areas; Environmental management; Seabird ecology; Wildlife habituation; Human use impacts; Pacific Rim National Park Reserve; Set back distances; Buffer zone

Bellquist, L. F., C. G. Lowe and J. E. Caselle. 2008. Fine-scale movement patterns, site fidelity, and habitat selection of ocean whitefish (Caulolatilus princeps). Fisheries Research. 91:325-335.

The fishery for California groundfishes is managed using broad species complexes, although some non-groundfish species are managed similarly due to the perception of shared behavioral characteristics. This study integrates acoustic telemetry and a GIS to quantify movement patterns of one such species, the ocean whitefish (Caulolatilus princeps) in a marine protected area. Seventeen ocean whitefish were tagged and actively tracked over multiple 24-h periods to measure fine-scale movement patterns. Home ranges based on 95% kernel utilization distributions averaged 20,439±28,492 (±S.D.)m2. Fish were active during the day, foraging over sand habitat at depths averaging 21±8m, but were inactive at night, taking refuge near rocky reefs at depths averaging 15±7m. Seventeen additional fish were tagged with coded acoustic transmitters and passively tracked using automated underwater acoustic receivers for up to 1 year. Approximately 75% of these fish exhibited long-term (1 year) fidelity to home ranges in the study area. Results suggest that MPAs can be an effective means of protecting populations of ocean whitefish and based on their habitat associations, ocean whitefish can be managed separately from other reef associated groundfishes.

Movement patterns; Home range; Site fidelity; Habitat selection; Marine protected area; Acoustic telemetry; Ocean whitefish

Benedetti-Cecchi, L., F. Pannacciulli, F. Bulleri, P. S. Moschella, L. Airoldi, G. Relini and F. Cinelli. 2001. Predicting the consequences of anthropogenic disturbance: large-scale effects of loss of canopy algae on rocky shores. Marine Ecology Progress Series. 214:137-150.

Anthropogenic disturbances affect natural populations and assemblages by interacting with fundamental ecological processes. Field experiments simulating the effects of human activities at the appropriate spatial and temporal scales are useful to understand these interactions and eventually to predict their ecological consequences. In the Mediterranean, low-shore habitats of rocky coasts are often dominated by canopy algae Cystoseira spp., but these species are frequently replaced by assemblages of turf-forming algae and mussel beds. We propose that anthropogenic disturbance is the proximate cause of loss of Cystoseira in the Mediterranean, and that the disappearance of canopy algae causes an increase in cover of turf-forming species in disturbed habitats. Two hypotheses were investigated to test this proposition: (1) canopy algae will be dominant in relatively pristine habitats while turf-forming algae will be more abundant in urban areas, and (2) removal of canopy algae in unpolluted areas will result in the development of assemblages similar to those found in urban areas. We tested the first hypothesis by comparing patterns in abundance of Cystoseira and turf-forming algae at a number of locations in urban areas and in areas far from distinct sources of anthropogenic disturbance in the northwest Mediterranean. The second hypothesis was tested by conducting a largescale manipulative experiment, involving the experimental removal of Cystoseira and several spatial and temporal repetitions of the manipulation. Turf-forming algae were always dominant in urban areas where Cystoseira was nearly absent. In contrast, canopy algae often dominated rocky shores in relatively pristine areas of the northwest Mediterranean. The removal of Cystoseira generally caused an increase in the percentage cover of turf-forming algae and a decrease in the abundance of invertebrates. These changes were already evident 4 mo after manipulation and were consistent at the spatial and temporal scales examined in the study. Assemblages in cleared patches were qualitatively similar to those occurring where Cystoseira was naturally absent, but quantitative differences in the relative abundance of several taxa were still evident by the end of the study. These results support a cause effect relationship between anthropogenic disturbance and loss of Cystoseira in the northwest Mediterranean and allow for quantitative predictions of the indirect consequences of disturbing canopy algae for the whole understory assemblage. Management options aimed at conserving these plants should simultaneously preserve other components of the assemblage.

Anthropogenic disturbance; Canopy algae; Cystoseira; Habitat formers; Indirect effects; Large-scale experiments; Prediction; Rocky shores; Turf-forming algae

Bennett, B. A. and C. G. Attwood. 1991. Evidence for recovery of a surf-zone fish assemblage following the establishment of a marine reserve on the southern coast of South Africa. Marine Ecology Progress Series. 75:173-181.

This study was designed to establish whether populations of fish species important in the catches of rock and surf anglers increased following the proclamation of the De Hoop Marine Reserve on the southern coast of South Africa Catch per unit effort (CPUE) and size frequency distributions of angling species were monitored approximately monthly by angling from the shore at 2 sites in the reserve. At one site sampling commenced 2 yr before the reserve was established and continued 4.5 yr thereafter, allowing comparisons of periods of exploitation and protection. The other site had a long history of minimal exploitation and data collected there 2.5 to 4.5 yr after complete protection was considered to represent an unexplolted condition. Ten species accounted for 99% of the catch. Following establishment of the reserve. CPUE increased for 6 of these (galjoen Coracinus capensis, dassie Diplodus sargus, wildeperd D. cervinus, white steenbras Lithognathus lithognathus, Cape stumpnose Rhabdosargus holubi and musselcracker Sparodon durbanensis) The catch rates of 2 species (C. capensis and D. sargus) improved 4 to 5 fold within 2 yr of protection and remained at these high levels, which were similar to the unexploited catch rates. Recoveries were slower amongst the other 4 species, their catch rates reaching 30 to 60% of the unexploited level after 2.5 to 4.5 yr of protection This study provides evidence of general stock recoveries of exploited fish species in a shallow marine habitat following protection within a marine reserve.

Berkeley, S. A., C. Chapman and S.M. Sogard. 2004. Maternal Age as a Determinant of Larval Growth and Survival in a Marine Fish, Sebastes Melanops. Ecology. 85(5): 1258-1264.

Relative body size has long been recognized as a factor influencing reproductive success in fishes, but maternal age has only recently been considered. We monitored growth and starvation resistance in larvae from 20 female black rockfish (Sebastes melanops), ranging in age from five to 17 years. Larvae from the oldest females in our experiments had growth rates more than three times as fast and survived starvation more than twice as long as larvae from the youngest females. Female age was a far better predictor of larval performance than female size. The apparent underlying mechanism is a greater provisioning of larvae with energy-rich triacylglycerol (TAG) lipids as female age increases. The volume of the oil globule (composed primarily of TAG) present in larvae at parturition increases with maternal age and is correlated with subsequent growth and survival. These results suggest that progeny from older females can survive under a broader range of environmental conditions compared to progeny from younger females. Age truncation commonly induced by fisheries may, therefore, have severe consequences for long-term sustainability of fish populations.

Berkeley, S. A., M. A. Hixon, R. J. Larson and M. S. Love. 2004. Fisheries Sustainability via Protection of Age Structure and Spatial Distribution of Fish Populations. Fisheries 29(8): 23-32.

Numerous groundfish stocks in both the Atlantic and Pacific are considered overfished, resulting in large-scale fishery closures. Fishing, in addition to simply removing biomass, also truncates the age and size structure of fish populations and often results in localized depletions. We summarize recent research suggesting that an old-growth age structure, combined with a broad spatial distribution of spawning and recruitment, is at least as important as spawning biomass in maintaining long-term sustainable population levels. In particular, there is evidence that older, larger female rockfishes produce larvae that withstand starvation longer and grow faster than the offspring of younger fish, that stocks may actually consist of several reproductively isolated units, and that recruitment may come from only a small and different fraction of the spawning population each year. None of these phenomena is accounted for in current management programs. We examine alternative management measures that address these specific issues and conclude that the best and perhaps only way to ensure old-growth age structure and complex spatial structure in populations of groundfish is through interconnected networks of marine reserves.

Blamey, L. K. and G. Branch. 2009. Habitat diversity relative to wave action on rocky shores: implications for the selection of marine protected areas. Aquatic Conservation: Marine and Freshwater Ecosystems. 19:645-657.

  1. Current selection of marine protected areas in South Africa is based on objective criteria including biogeographic representation and habitat heterogeneity. This paper specifically examines rocky shores on the west coast of South Africa to determine whether they are divisible into discrete 'habitats' that need independent conservation.
  2. Seventeen rocky shores spanning the full spectrum of wave exposure were compared in terms of maximum wave forces, biomass, species richness and diversity among zones and sites. Three biotic assemblages were identified, characterizing sheltered, semi-exposed to exposed, and very exposed habitats. Differences among these were clear-cut low on the shore but disappeared at the top of the shore where wave action was attenuated and desiccation uniformly intense.
  3. The recognition of three discrete biologically-defined habitats means that rocky shores cannot be regarded as a uniform habitat for conservation purposes. All three components need protection if the full spectrum of rockyshore communities is to be conserved.
  4. It is argued that this approach allows habitats to be defined in an objective manner, and that once this has been done, habitat heterogeneity constitutes a better measure of conservation value of an area than a 'hotspot' approach based on species richness and endemism.

intertidal biomass; limpets; mussels; marine protected areas; rocky shores; wave action

Blanchette, C. A., B. R. Broitman and S. D. Gaines. 2006. Intertidal community structure and oceanographic patterns around Santa Cruz Island, CA, USA. Marine Biology. 149:689-701.

Recent studies suggest that nearshore oceanographic conditions can have important effects on the structure of benthic communities. On Santa Cruz Island (SCI), CA, USA there is a persistent difference in mean annual sea surface temperature (SST) around the island due to its location at the confluence of opposing cold and warm ocean current systems. Over the course of a 4-year study (1997–2001) seawater nutrient and chl-a concentrations, algal tissue C:N ratios, recruitment and growth of filter-feeders (barnacles and mussels), and intertidal community structure were measured at six intertidal sites around the island. There were strong associations between remotely sensed SST and patterns of community structure. Macrophyte abundance was highest at sites with persistently low SST, while recruitment, abundance, and growth of filter-feeding invertebrates were strongly, positively correlated with SST. The cold-water sites were associated with higher nutrient concentrations and lower algal C:N ratios, particularly in the winter months. Values of chl-a were generally low and variable among sites, and were not correlated with the predominant SST gradient. Recruitment of barnacles and mussels was positively correlated with adult abundance across all sites. While detailed experimental studies are needed to further evaluate the mechanisms underlying community dynamics, these results indicate that the confluence of cold- and warm-water masses around SCI may determine the contrasting patterns of intertidal community structure.

Blyth-Skyrme, R. E., P. J. Hart, M. J. Kaiser, G. Edwards-Jones and D. Palmer. 2007. Evidence for greater reproductive output per unit area in areas protected from fishing. Canadian Journal of Fisheries and Aquatic Sciences. 64:1284-1289.

Marine protected areas are advocated as an essential management tool to ensure the sustainable use of marine resources by providing insurance against over-exploitation and through the provision of refuge for a large biomass of sexually mature adults. Using a unique fishing gear-restriction, voluntary management system as a large-scale experiment, we found that adult scallops (Pecten maximus) within areas protected from towed bottom-fishing gear had heavier adductor muscle tissue and gonads that were 19%-24% heavier than those of scallops in fished areas, while other body and age characteristics were similar in both areas. The scallops within the protected area also occurred at a much higher abundance than adjacent, chronically fished (× 12.83) and wider commercially exploited (× 2.18) areas. These results provide evidence that the use of towed bottom-fishing gear can further exacerbate the effects of overfishing through the suppression of the reproductive potential of individuals of similar body size. These findings underline the utility of using closed areas as tools for fisheries conservation of sedentary species of commercial importance.

Blyth-Skyrme, R. E., M. J. Kaiser, J. G. Hiddink, G. Edwards-Jones and P. J. B. Hart. 2006. Conservation benefits of temperate marine protected areas: variation among fish species. Conservation Biology. 20:811-820.

Marine protected areas, and other fishery management systems that impart partial or total protection from fishing, are increasingly advocated as an essential management tool to ensure the sustainable use of marine resources. Beneficial effects for fish species are well documented for tropical and reef systems, but the effects of marine protected areas remain largely untested in temperate waters. We compared trends in sport-fishing catches of nine fish species in an area influenced by a large (500-km2) towed-fishing-gear restriction zone and in adjacent areas under conventional fishery management controls. Over the period 1973-2002 the mean reported weight of above-average-sized (trophy) fish of species with early age at maturity and limited home range was greatest within the area influenced by the fishing-gear restriction zone. The reported weight of trophy fish of species that mature early also declined less and more slowly over time within the area influenced by the fishing-gear restriction zone. Importantly, the mean reported weight of trophy fish of species that mature late and those that undertake extensive spatial movements declined at the same rate in all areas. Hence these species are likely to require protected areas >500 km2 for effective protection. Our results also indicated that fish species with a localized distribution or high site fidelity may require additional protection from sport fishing to prevent declines in the number or size of fish within the local population.

Bobko, S.J. and S.A. Berkeley. 2004. Maturity, ovarian cycle, fecundity, and age-specific parturition of black rockfish (Sebastes melanops). Fisheries Bulletin 102:418-429.

From 1995 to 1998, we collected female black rockfish (Sebastes melanops) off Oregon in order to describe their basic reproductive life history and determine age-specific fecundity and temporal patterns in parturition. Female black rockfish had a 50% probability of being mature at 394 mm fork length and 7.5 years-of-age. The proportion of mature fish age 10 or older significantly decreased each year of this study, from 0.511 in 1996 to 0.145 in 1998. Parturition occurred between mid-January and mid-March, and peaked in February. We observed a trend of older females extruding larvae earlier in the spawning season and of younger fish primarily responsible for larval production during the later part of the season. There were differences in absolute fecundity at age between female black rockfish with prefertilization oocytes and female black rockfish with fertilized eggs; fertilized-egg fecundity estimates were considered superior. The likelihood of yolked oocytes reaching the developing embryo stage increased with maternal age. Absolute fecundity estimates (based on fertilized eggs) ranged from 299,302 embryos for a 6-year-old female to 948,152 embryos for a 16-year-old female. Relative fecundity (based on fertilized eggs) increased with age from 374 eggs/g for fish age 6 to 549 eggs/g for fish age 16.

Bohnsack, J. A.. 2000. A comparison of the short-term impacts of no-take marine reserves and minimum size limits. Bulletin of Marine Science 66(3): 635-650.

Establishing no-take marine reserves (NTRs) displaces fishing effort to surrounding areas, creating concerns about short-term impacts on resources and fishers before long-term benefits can accrue. Models were developed to compare the effects of short-term displacement caused by of NTRs to effects of minimum size limits (MSLs), one of the most widely applied management measures in the southeastern U.S. Projected impacts on resource protection and fishers were assessed on the basis of the portion of a population either protected or legally available to fishing. In all cases, existing MSLs had greater impact on total numbers of fish landed (reduced by 38 to 70%) than on the weight of total landings (reduced by 14 to 26%). NTRs protected sedentary species in approximate proportion to the total habitat closed to fishing but provided less protection as species mobility increased. These differences in protection due to mobility were greater for reserves covering small percentages of total habitat. Predicted short-term displacement impacts on fishers were low for reserves covering small percentages of the total habitat, but they increased exponentially as the percentage of total habitat closed increased. Displacement impacts were predicted to be highest for fishers pursuing sedentary species and decreased for more mobile species. Detrimental impacts to surrounding habitat from displacement depended on initial fishery conditions, gear type, and the total proportion of habitat closed. Although more fishers are affected by the no-take rule, concerns about short-term displacement impacts appear to be exaggerated. Some opposition to establishing NTRs may result in part because the no-take provision is more difficult to circumvent than other regulations. When combined with traditional management tools, no-take reserves offer increased flexibility for supporting fisheries and protecting resources.

Bonacci, S., A. Iacocca, S. Fossi, L. Lancini, T. Caruso, I. Corsi, S. Focardi. (2007). Biomonitoring Aquatic Environmental Quality in a Marine Protected Area: A Biomarker Approach. Ambio 36(4): 308-215.

The main aims of the present study, conducted in the framework of the MONIQUA–Egadi Scientific Project, were twofold: first, to make the first step in the development and validation of an ecotoxicological approach for the assessment of marine pollution in coastal environments on the basis of a set of biomarker responses in new sentinel species; and second, to obtain preliminary information on environmental quality in an Italian marine protected area, the Egadi Islands (Sicily). Several cytochrome P450–dependent mixed-function oxidase activities were measured in the following sentinel species: rainbow wrasse Coris julis, gastropod limpet Patella caerulea, and sea urchin Paracentrotus lividus. The results suggest that specimens from the Favignana Harbor may be exposed to P450 inducers, whereas most of the other sites seem to share similar environmental quality. The proposed approach has potential for assessment of environmental quality in marine protected areas.

Paracentrotus lividus, cytochrome, biomonitoring, marine protected area

Botsford, L. W. 2001. Physical influences on recruitment to California Current invertebrate populations on multiple scales. ICES Journal of Marine Science. 58:1081-1091.

Studies of recruitment to Dungeness crab (Cancer magister) and red sea urchin (Strongylocentrotus franciscanus) populations have focused on recruitment variability on interannual, 1000-km scales. These studies have identified correlations between recruitment and variables indicating ENSO conditions and wind-forced larval transport. On longer scales, our understanding of biologically important physical variability in the California Current has recently been enhanced by an appreciation of semi-basin, decadal changes. Intensification of the Aleutian low-pressure zone in the mid-1970s had a clear positive effect of biological productivity in the Gulf of Alaska, and less obvious negative effects on productivity in the California Current. On shorter scales, an increasing appreciation of the effect of dispersal patterns on population dynamics and the potential of spatially explicit management schemes provide the impetus for studying processes such as alongshore spatial variability in recruitment and the underlying daily variability in circulation over 100-km distances. In the 1980s, physical studies of coastal circulation in response to daily fluctuations in upwelling winds identified brief periods of northward, onshore flow interrupting the offshore, southward flows associated with active upwelling. In the 1990s, concurrent monitoring of biological and physical conditions revealed that these flows transport late-stage invertebrate larvae from a retention zone in the lee of a local promontory to settlement locations, producing specific spatial patterns of recruitment. Variability in recruitment of both crabs and sea urchins is thus driven by daily temporal variability in upwelling winds and 100-km spatial variability in coastal topography. Interannual recruitment variability appears to depend on ENSO-related biological productivity and larval transport in ways that vary among species, but are not completely understood. Observations are consistent with coastwide, interannual variability being driven by biological productivity (i.e. ENSO/non-ENSO conditions), while the upwelling relaxation mechanism sets the spatial scale, and decadal, semi-basin variability modulates the frequency of ENSO conditions.

Dungeness crab; ENSO; marine reserves; red sea urchin; regime shift; scales; settlement; upwelling relaxation

Botsford, L.W., F. Micheli, and A. Hastings. 2003. Principles for the Design of Marine Reserves. Ecological Applications 13(1) Supplement: S25-S31

The theory underlying the design of marine reserves, whether the goal is to preserve biodiversity or to manage fisheries, is still in its infancy. For both of these goals, there is a need for general principles on which to base marine reserve design, and because of the paucity of empirical experience, these principles must be based on models. However, most of the theoretical studies to date have been specific to a single situation, with few attempts to deduce general principles. Here we attempt to distill existing results into general principles useful to designers of marine reserves. To answer the question of how fishery management using reserves compares to conventional management, we provide two principles: (1) the effect of reserves on yield per recruit is similar to increasing the age of first capture, and (2) the effect of reserves on yield is similar to reducing effort. Another two principles answer the question of how to design reserve configurations so that species with movement in various stages will be sustainable: (3) higher juvenile and adult movement lowers sustainability of reserves for biodiversity, but an intermediate level of adult movement is required for reserves for fishery management, and (4) longer larval dispersal distance requires larger reserves for sustainability. These principles provide general guidelines for design, and attention to them will allow more rapid progress in future modeling studies. Whether populations or communities will persist under any specific reserve design is uncertain, and we suggest ways of dealing with that uncertainty.

Botsford, L.W., D. R. Brumbaugh, C. Grimes, J. B. Kellner, J. L. Largier, M. R. O'Farrell, S. Ralston, E. Soulanille and V. Wespestad. 2009. Connectivity, sustainability, and yield: bridging the gap between conventional fisheries management and marine protected areas. Reviews in Fish Biology and Fisheries. 19:69-95.

A substantial shift toward use of marine protected areas (MPAs) for conservation and fisheries management is currently underway. This shift to explicit spatial management presents new challenges and uncertainties for ecologists and resource managers. In particular, the potential for MPAs to change population sustainability, fishery yield, and ecosystem properties depends on the poorly understood consequences of three critical forms of connectivity over space: larval dispersal, juvenile and adult swimming, and movement of fishermen. Conventional fishery management describes the dynamics and current status of fish populations, with increasing recent emphasis on sustainability, often through reference points that reflect individual replacement. These compare lifetime egg production (LEP) to a critical replacement threshold (CRT) whose value is uncertain. Sustainability of spatially distributed populations also depends on individual replacement, but through all possible paths created by larval dispersal and LEP at each location. Model calculations of spatial replacement considering larval connectivity alone indicate sustainability and yield depend on species dispersal distance and the distribution of LEP created by species habitat distribution and fishing mortality. Adding MPAs creates areas with high LEP, increasing sustainability, but not necessarily yield. Generally, short distance dispersers will persist in almost all MPAs, while sustainability of long distance dispersers requires a specific density of MPAs along the coast. The value of that density also depends on the uncertain CRT, as well as fishing rate. MPAs can increase yield in areas with previously low LEP but for short distance dispersers, high yields will require many small MPAs. The paucity of information on larval dispersal distances, especially in cases with strong advection, renders these projections uncertain. Adding juvenile and adult movement to these consequences primarily in terms of the goals and currencies of greatest interest in fisheries and conservation of marine resources: sustainability and yield. Sustainability is the ability of the population and the associated fishery to persist into the long-term future. Yield is a benefit in the management of a fishery, and a decline in yield is a potential cost when setting aside an MPA solely for conservation. We begin by reviewing the ways in which conventional fisheries management seeks sustainability and high yield, and the uncertainties involved. We then describe the dynamics of sustainability in spatially distributed populations with MPAs as we add the three types of connectivity. Finally, we present synthetic conclusions that encapsulate our current understanding of connectivity and MPAs, and identify future challenges in this arena.

Connectivity; Marine reserve; Metapopulation; Fisheries management; Dispersal; Home range

Boudouresque, C. F. and M. Verlaque. (2005). Nature conservation, Marine Protected Areas, sustainable development and the flow of invasive species to the Mediterranean Sea. France, Port-Cros National Park: 29-54.

The Mediterranean flora and fauna seem particularly rich. One of the reasons for this wealth is their high rate of endemism. In addition, the Mediterranean harbours a large variety of communities. Some of them are unique, giving the Mediterranean its touch of originality. A number of these species and communities are threatened by human activities. Until recently, the legal protection of marine species mainly concerned mammals, turtles and birds. Since 1996, 55 species of Mediterranean marine macrophytes, invertebrates and fishes were registered in Appendices I and II of the Conventions of Bern and Barcelona. Of course, the protection of species is intimately linked to the protection of their habitats and resources: a number of Marine Protected Areas (MPAs) were set up. In addition to the setting up of conservatories for threatened species and habitats, the targets of MPAs are to establish no-take areas where fish density and sex-ratio make spawning possible (which subsequently export eggs, larvae and adults to surrounding non protected areas) and to manage the different uses of the sea (e.g. artisanal fishing, recreational fishing and tourism) in a rational way, so that they do not conflict with each other or with conservation aims. Furthermore, protected areas are no longer seen as "islands" of nature surrounded by incompatible resource uses but are part of a broader regional approach to land and sea management.

Mediterranean, introduced species, flora and fauna, marine protected area

Broitman, B. R., C. A. Blanchette, and S. D. Gaines. (2007). Recruitment of intertidal invertebrates and oceanographic variability at Santa Cruz Island, California, U.S.A.. 1-24.

To examine geographical variation in oceanographic forcing on larval delivery, we studied spatial and temporal variability in larval recruitment of mussels and barnacles in a key oceanographic region around Santa Cruz Island, California, U.S.A. Larval recruitment patterns differed among sites located on the eastern and western shores of the island associated with differences in oceanographic regimes. Western sites had low, but variable sea surface temperatures, while eastern sites were warmer (1°C-1.5°C higher) and less variable. Larval arrival was extremely low at western sites relative to eastern sites. Mussels and barnacles differed in the duration and seasonality of larval recruitment. Mussels recruited over a long period between winter and summer, while barnacle recruitment occurred in pulses in spring-summer. Mussel recruitment was not correlated with sea surface temperature anomalies, while barnacle recruitment was significantly and positively correlated to temperature anomalies with time lags ranging from 0 to 3 months across all sites. Oceanographic and larval recruitment patterns suggest that western sites are dominated by an energetic flux of cold, recently upwelled water depleted of larvae, while eastern sites receive high numbers of larvae associated with the influx of warmer surface water likely originating outside the Santa Barbara Channel.

Santa Cruz Island, California, mussels, larval arrival, recruitment

Broitman, B. R., C. A. Blanchette, B. A. Menge, J. Lubchenco, C. Krenz, M. Foley, P. T. Raimondi, D. Lohse and S. D. Gaines. 2008. Spatial and temporal patterns of invertebrate recruitment along the west coast of the United States. Ecological Monographs. 78:403-421.

Patterns of recruitment in marine ecosystems can reflect the distribution of adults, dispersal by ocean currents, or patterns of mortality after settlement. In turn, patterns of recruitment can play an important role in determining patterns of adult abundance and community dynamics. Here we examine the biogeographic structure of recruitment variability along the U.S. West Coast and examine its association with temperature variability. From 1997 to 2004 we monitored monthly recruitment rates of dominant intertidal invertebrates, mussels and barnacles, at 26 rocky shore sites on the West Coast of the United States, from northern Oregon to southern California, a span of 1750 km of coastline. We examined spatial variation in the dynamics of recruitment rates and their relationship to coastal oceanography using satellite-derived time series of monthly sea surface temperature (SST). Recruitment rates showed a biogeographic structure with large regions under similar dynamics delimited by abrupt transitions. The seasonal peak in recruitment rates for both mussels and barnacles changed from a late summer/early fall peak in Oregon to winter or early spring in northern California, and then back toward summer in southern California. Recruitment rates varied greatly in magnitude across the latitudinal range. The barnacle Balanus glandula and mussels (Mytilus spp.) showed a decline of two orders of magnitude south of Oregon. In contrast, recruitment rates of barnacles of the genus Chthamalus showed a variable pattern across the region examined. The spatial distribution of associations between raw SST and recruitment rates for all species showed positive associations, indicating recruitment during warm months, for all species in Oregon, northern California, and several sites in south-central California. By considerably extending the spatial and temporal scales beyond that of previous studies on larval recruitment rates in this system, our study has identified major biogeographic breaks around Cape Blanco and Point Conception despite considerable spatial and temporal variation within each region and among species. These large differences in recruitment rates across biogeographic scales highlight the need for a better understanding of larval responses to ocean circulation patterns in the conservation and management of coastal ecosystems.

advanced very-high resolution radiometer (AVHRR) satellite; Balanus glandula; Chthamalus spp.; community structure; geographic variation; intertidal invertebrates; Mytilus spp.; recruitment; West Coast, USA

Brown, C. A., G. A. Jackson, S. A Holt, G. J. Holt. (2005). Spatial and temporal patterns in modeled particle transport to estuarine habitat with comparisons to larval fish settlement patterns. Estuarine, Coastal and Shelf Science 64: 33-46.

Larval fish settlement in estuarine nursery areas is the end result of numerous biological and physical processes. We used a numerical circulation model coupled to a particle transport model to examine the role that physics play in determining settlement patterns of red drum larvae (Sciaenops ocellatus) in nursery habitat along the Texas coast. We examined supply at various spatial scales (supply to inlet, bays, and individual settlement sites). Temporal patterns in larval settlement in Aransas Bay, Texas, are correlated with several indices of modeled particle supply (number of particles inside the bays, integrated particle input to Lydia Ann Channel, and cumulative number of competent particles in Lydia Ann Channel). High abundances of recently settled red drum in Aransas Bay result from a combination of high larval input, limited habitat for settlement, and proximity of habitat to the inlet. In contrast, larval settlement in Corpus Christi and Redfish Bays does not appear to be related to modeled measures of larval supply. Modeled particle supply at the bay-scale suggests that difference in the abundance of recently settled red drum between the bays may be related to larval supply normalized by the amount available settlement habitat within the bay.

Sciaenops ocellatus; red drum; fish larvae; larval transport; estuary; Texas; nursery habitat; modeling

Brown, P. J. and R. B. Taylor. 1999. Effects of trampling by humans on animals inhabiting coralline algal turf in the rocky intertidal. Journal of Experimental Marine Biology and Ecology. 235:45-53.

This paper investigates the effects of trampling by humans on the fauna associated with articulated coralline algal turf. Patches of intertidal turf in a low-use area of the Cape Rodney to Okakari Point Marine Reserve (in north-eastern New Zealand) were experimentally trampled over 5 days at three levels that fell within those measured in a part of the reserve subject to heavy 5 visitor use. Two days after trampling ended there were ~ 2 * 105 individual macrofauna (.500 2 mm) per m in control plots, but densities declined with increasing trampling intensity in the treatment plots, and were reduced to 50% of control values at the highest trampling intensity. Densities of five of the eight commonest taxa were negatively correlated with trampling intensity, with polychaetes being particularly susceptible to low levels of trampling. Three months after trampling ended densities of all taxa had returned to control values, with the exception of polychaetes. Reductions in animal densities are tentatively attributed to the loss of turf and associated sand caused by trampling, rather than direct destruction of the organisms. Given the likely importance of these abundant and productive animals in the rocky reef ecosystem, and their vulnerability to low levels of trampling by humans, we conclude that the effective management of marine protected areas may necessitate total exclusion of humans in some cases.

Algae; Coralline turf; Epifauna; Human impact; Intertidal; New Zealand; Marine reserve; Trampling

Byers, J. E. 2005. Marine reserves enhance abundance but not competitive impacts of a harvested nonindigenous species. Ecology. 86:487-500.

Marine reserves are being increasingly used to protect exploited marine species. However, blanket protection of species within a reserve may shelter nonindigenous species that are normally affected by harvesting, intensifying their impacts on native species. I studied a system of marine reserves in the San Juan Islands, Washington, USA, to examine the extent to which marine reserves are invaded by nonindigenous species and the consequences of these invasions on native species. I surveyed three reserves and eight non-reserves to quantify the abundance of intertidal suspension-feeding clam species, three of which are regionally widespread nonindigenous species (Nuttallia obscurata, Mya arenaria, and Venerupis philippinarum). Neither total nonindigenous nor native species' abundance was significantly greater on reserves. However, the most heavily harvested species, V. philippinarum, was significantly more abundant on reserves, with the three reserves ranking highest in Venerupis biomass of all 11 sites. In contrast, a similar, harvested native species (Protothaca staminea) did not differ between reserves and non-reserves.

I followed these surveys with a year-long field experiment replicated at six sites (the three reserves and three of the surveyed non-reserve sites). The experiment examined the effects of high Venerupis densities on mortality, growth, and fecundity of the confamilial Protothaca, and whether differences in predator abundance mitigate density-dependent effects. Even at densities 50% higher than measured in the field survey, Venerupis had no direct effect on itself or Protothaca; only site, predator exposure, and their interaction had significant effects. Analyses incorporating environmental variables tracked at each site indicated that crab biomass most heavily influenced clam responses, causing lower growth of both species and higher mortality of Venerupis, whose annualized loss rate was 50% when exposed to predators. A laboratory prey choice experiment indicated that Cancer productus, an influential intertidal crab predator, favored small adult Venerupis at least 1.7 times over Protothaca. Venerupis' high susceptibility to excavating crab and human predators, as well as its faster growth compared to Protothaca can be explained by its shallower burial depth. By growing quickly and residing near the surface, Venerupis apparently absorbs the brunt of harvest pressure while Protothaca maintains high biomass even outside of reserves.

apparent competition; clams; exotic species; fisheries; marine protected areas; mixed effects models; Nuttallia obscurata; Protothaca staminea; San Juan Islands; Washington (USA); spatially replicated experiments; Tapes japonica; Venerupis philippinarum

Carr, M.H., J.E. Neigel, J.A. Estes, S. Andelman, R.R. Warner, and J.L. Largier. 2003. Comparing Marine and Terrestrial Ecosystems: Implications for the Design of Coastal Marine Reserves. Ecological Applications 13(1) Supplement: S90-S107.

Concepts and theory for the design and application of terrestrial reserves is based on our understanding of environmental, ecological, and evolutionary processes responsible for biological diversity and sustainability of terrestrial ecosystems and how humans have influenced these processes. How well this terrestrial-based theory can be applied toward the design and application of reserves in the coastal marine environment depends, in part, on the degree of similarity between these systems. Several marked differences in ecological and evolutionary processes exist between marine and terrestrial ecosystems as ramifications of fundamental differences in their physical environments (i.e., the relative prevalence of air and water) and contemporary patterns of human impacts. Most notably, the great extent and rate of dispersal of nutrients, materials, holoplanktonic organisms, and reproductive propagules of benthic organisms expand scales of connectivity among nearshore communities and ecosystems. Consequently, the ''openness'' of marine populations, communities, and ecosystems probably has marked influences on their spatial, genetic, and trophic structures and dynamics in ways experienced by only some terrestrial species. Such differences appear to be particularly significant for the kinds of organisms most exploited and targeted for protection in coastal marine ecosystems (fishes and macroinvertebrates). These and other differences imply some unique design criteria and application of reserves in the marine environment. In explaining the implications of these differences for marine reserve design and application, we identify many of the environmental and ecological processes and design criteria necessary for consideration in the development of the analytical approaches developed elsewhere in this Special Issue.

Carson, H. S. andB. T. Hentschel. 2006. Estimating the dispersal potential of polychaete species in the Southern California Bight: implications for designing marine reserves. Marine Ecology Progress Series. 316:105-113.

Using known and inferred life-history information, we estimated the dispersal potential of 501 polychaete species sampled during a 1998 monitoring study in the Southern California Bight. We tested the hypothesis that species having life-history traits that suggest long-distance dispersal will be encountered more frequently throughout the region than will species having life histories that suggest limited dispersal. When all 501 species and all 200 sampling sites were analyzed, occurrence frequency (percentage of sites at which a species was collected) was not significantly related to dispersal potential. When data from 53 shelf sites in the Channel Islands were analyzed separately from collections at 147 mainland-shelf sites, there was a significant positive relationship between dispersal potential and occurrence frequency at the island sites but not at the mainland sites. Of the 501 species, 119 were collected only at island sites, 98 were found only at mainland sites, and 284 were found at both island and mainland sites. The majority of the 'island only' species had life-history traits indicating low dispersal potential. In contrast, only 13% of the 'mainland only' species were categorized as having low dispersal potential. The 'cosmopolitan' species had a broad range of dispersal potential. Models indicate that efforts to conserve biodiversity by establishing Marine Protected Areas (MPAs) must consider species' dispersal. In the shelf communities of the Southern California Bight, networks of small reserves that are located in existing areas of high diversity should succeed in the Channel Islands, where the majority of polychaete species tend to have limited dispersal potential. On the mainland shelf, however, designing effective MPAs will be more challenging due to the prevalence of species that have a greater potential for long-distance dispersal to or from unprotected sites.

Dispersal; Larval ecology; Life history; Marine Protected Area; Marine reserve; Polychaete

Castilla, J. C. 1999. Coastal marine communities: trends and perspectives from human-exclusion experiments. Trends in Ecology and Evolution. 14:280-283.

The ecological roles of humans in marine communities have been poorly studied. Humans have special characteristics, such as culture, and are perceived as complex ecological actors. Observations and experiments conducted in coastal (rocky intertidal and nearshore) 'no-take' areas or reserves in Chile and around the world have permitted a better understanding of the role played by humans as top predators and the resulting trophic-cascade effects along the food-webs. These studies have revealed an urgent need to incorporate humans into ecological studies and have helped to promote links between ecology and social sciences.

Casu, D., G. Ceccherelli , M. Curini-Galletti and A. Castelli. 2006. Human exclusion from rocky shores in a mediterranean marine protected area (MPA): An opportunity to investigate the effects of trampling. Environmental Research. 62:15-32.

The effect of human trampling on the abundance of small invertebrates inhabiting rocky shallow bottoms was studied at Asinara Island MPA. To this aim we have conducted two experiments. The first was a quantitative study and tested the hypothesis that small invertebrates are more abundant at no-entry locations than at the location visited by tourists through time (before, during and after tourist season). The second was a manipulative experiment and tested the hypothesis that the abundance of small invertebrates is indirectly related to experimental trampling intensities. The effect due to tourist visitation was not highlighted on overall assemblages, suggesting that present seasonal tourist load at the MPA does not cause a significantly negative effect on the zoobenthic community studied. Although tourists exhibited trampling activity at the visited location, none of taxa examined showed a significant lower abundance during and strictly after the end of seasonal tourism peak in the visited location, rather than at control locations. However, results obtained with the second experiment suggested that the effects of different experimental trampling intensities on small invertebrates were variable among taxa. The experimental trampling caused immediate declines in the density of tanaids, nematodes, acari, bivalves, gammarids, echinoderms, isopods, and harpacticoids. For some of these taxa a recovery in abundance was observed within one month.

Asinara island; Benthic invertebrates; Marine protected area; Mediterranean sea; Rocky shore; Trampling

Chittaro, P. M., I. C. Kaplan, A. Keller, and P. S. Levin. (2009). Trade-Offs between Species Conservation and the Size of Marine Protected Areas. Conservation Biology.

Moving from single-species- to ecosystem-based management requires an understanding of how community-level attributes such as diversity change with area. We used survey data from bottom trawls to examine spatial patterns of species richness in U.S. Pacific coastal fishes. Specifically, we generated and compared species–area relationships (SARs) for species classified into several groups on the basis of maximum body size, trophic level, diet, maximum depth, geographic affinity, and taxonomic order. Because SARs among groups were not parallel and z values varied significantly for several groups, groups of species were underor overrepresented (depending on the size of the area) relative to their proportions in the entire community (i.e., entire U.S. Pacific coast). In this way, differences in SARs help demonstrate trade-offs between species representation and coastal area and suggest strategies (such as targeting the protection of habitats and locations where a particular species or groups of species are maximized) that may minimize the size of marine protected areas (MPAs) but protect diversity at the level of the community and functional group.

biodiversity conservation; marine protected areas; species–area relationships

Christie, M. R., D. W. Johnson, C. D. Stallings, and M. A. Hixon. (2010). Self-recruitment and sweepstakes reproduction amid extensive gene flow in a coral-reef fish. Molecular Ecology 19: 1042-1057.

Identifying patterns of larval dispersal within marine metapopulations is vital for effective fisheries management, appropriate marine reserve design, and conservation efforts. We employed genetic markers (microsatellites) to determine dispersal patterns in bicolour damselfish (Pomacentridae: Stegastes partitus). Tissue samples of 751 fish were collected in 2004 and 2005 from 11 sites encompassing the Exuma Sound, Bahamas. Bayesian parentage analysis identified two parent–offspring pairs, which is remarkable given the large population sizes and 28 day pelagic larval duration of bicolour damselfish. The two parent–offspring pairs directly documented self-recruitment at the two northern-most sites, one of which is a long-established marine reserve. Principal coordinates analyses of pair-wise relatedness values further indicated that self-recruitment was common in all sampled populations. Nevertheless, measures of genetic differentiation (FST) and results from assignment methods suggested high levels of gene flow among populations. Comparisons of heterozygosity and relatedness among samples of adults and recruits indicated spatially and temporally independent sweepstakes events, whereby only a subset of adults successfully contribute to subsequent generations. These results indicate that self-recruitment and sweepstakes reproduction are the predominant, ecologically-relevant processes that shape patterns of larval dispersal in this system.

bicolour damselfish, larval dispersal, multivariate statistics, parentage, population connectivity, relatedness

Claessen, D., A. S. de Vos and A. M. de Roos. 2009. Bioenergetics, overcompensation, and the source-sink status of marine reserves. Canadian Journal of Fisheries and Aquatic Sciences. 66:1059-1071.

One of the hypothesized functions of marine protected areas (MPAs) is to serve as sources of biomass, with biomass spilling over from the reserve into neighbouring, harvested areas. We argue that the net larval flow (from or to the marine reserve) depends on between-area differences in the population-level biomass production rate, whereas the direction of adult flow depends on differences in the biomass standing stock. Hence, an important question is whether population-level biomass production increases (overcompensation) or decreases (undercompensation) with increased per capita mortality. We show that in a consumer-resource context, the source-sink status of an MPA may depend on the details of the individual-level bioenergetics, as well as on the dispersal rates of larvae and adults. We compare two classic bioenergetic models (net-production vs. gross-production allocation). The net-production model predicts that population-level reproduction may increase with mortality (overcompensation), whereas gross-production allocation always results in undercompensation. We show that models often implicitly assume gross-production allocation, thus potentially overestimating the capacity of MPAs to source unprotected areas. We briefly discuss results of two other models (a simplified, logistic model and a size-structured model), suggesting that the relation between overcompensation and the larval sink status of MPAs is general.

Claudet, J., C. W. Osenberg, L. Benedetti-Cecchi, P. Domenici, J. A. Garcia-Charton, A. Perez-Ruzafa, F. Badalamenti, J. Bayle-Sempere, A. Brito, F. Bulleri, J. M. Culioli, M. Dimech, J. M. Falcon, I. Guala, M. Milazzo, J. Sanchez-Meca, P. J. Somerfield, B. Stobart, F. Vandeperre, C. Valle and S. Planes. 2008. Marine reserves: size and age do matter. Ecology Letters. 11:481-489.

Marine reserves are widely used throughout the world to prevent overfishing and conserve biodiversity, but uncertainties remain about their optimal design. The effects of marine reserves are heterogeneous. Despite theoretical findings, empirical studies have previously found no effect of size on the effectiveness of marine reserves in protecting commercial fish stocks. Using 58 datasets from 19 European marine reserves, we show that reserve size and age do matter: Increasing the size of the no-take zone increases the density of commercial fishes within the reserve compared with outside; whereas the size of the buffer zone has the opposite effect. Moreover, positive effects of marine reserve on commercial fish species and species richness are linked to the time elapsed since the establishment of the protection scheme. The reserve size-dependency of the response to protection has strong implications for the spatial management of coastal areas because marine reserves are used for spatial zoning.

Asymmetrical analysis of variance; coastal marine ecosystems; commercial species; fish assemblages; heterogeneity; marine protected area; marine reserve age; marine reserve design; marine reserve network; marine reserve size; weighted meta-analysis

Cole, R. G., T. M. Ayling and R. G. Creese. 1990. Effects of marine reserve protection at Goat Island, northern New Zealand. New Zealand Journal of Marine and Freshwater Research. 24:197-210.

The possible effects that marine reserve protection has had on densities of some reef fish and large invertebrates were investigated near Leigh (north-eastern New Zealand) by a series of sampling programmes between 1976 and 1988. Fish counts at intervals during the 6 years after the initial establishment of the Cape Rodney to Okakari Point Marine Reserve in 1975 suggested that red moki (Cheilodactylus spectabilis) had increased in abundance whereas five others had remained at approximately constant densities. A comparison of data between 1978 and 1988 also revealed few consistent differences in fish abundances. A detailed survey in 1988 between sites inside and outside the marine reserve showed no clear patterns for sea urchins (Evechinus chloroticus) and several fish; trends for increased abundances in the marine reserve of fish such as snapper Pagrus (=Chrysophrys) auratus, blue cod (Parapercis colias), and red moki; a very striking increase in numbers of rock lobsters (Jasus edwardsii) within the marine reserve; and an obvious trend for increased size of snapper in the marine reserve. Most of the trends, however, were not statistically significant, owing largely to the low power of the tests used. Although it is now generally accepted that the creation of marine reserves such as the one at Leigh results in increased abundances of certain organisms, our study highlights the difficulty of rigorously demonstrating this, especially for patchily distributed and mobile fish species.

Marine reserve; fish; abundance; rock lobster, sea urchin

Coleman, F.C. , W.F. Figueira, J.S. Ueland and L.B. Crowder. 2004. The Impact of United States Recreational Fisheries on Marine Fish Populations. Scienceexpress. 3pp.

We evaluate the commercial and recreational fishery landings over the past 22 years, first at the national level, second for populations of concern (those that are overfished or experiencing overfishing), and finally by region. Recreational landings in 2002 account for 4% of total marine fish landed in the USA. With large industrial fisheries excluded (e.g., menhaden and pollock), the recreational component rises to 10%. Among populations of concern, recreational landings in 2002 account for 23% of the total nationwide, rising to 38% in the South Atlantic and 64% in the Gulf of Mexico. Moreover, it affects many of the most valued overfished species, including red drum, bocaccio, and red snapper, all of which are taken primarily in the recreational fishery.

Collins, M.R., T.I.J. Smith, W.E. Jenkins, M.R. Denson. 2002. Small Marine Reserves May Increase Escapement of Red Drum. Fisheries 27(2): 20-24.

An experimental stock enhancement program was conducted in Port Royal Sound estuary, South Carolina, in which cultured juvenile red drum (Sciaenops ocellatus, 2-3 cm TL, ~40 days old) were released into a system of shallow tidal creeks that flow into the Colleton River. All fish were immersed in oxytetracycline (OTC) prior to release to produce an identifiable, chemical mark on the otoliths. The release area was typical of primary nursery habitat in this region. For four years post-stocking, fish were collected throughout the sound using hook and line, spear, and trammel net. Otoliths were examined for OTC marks to determine which fish were of hatchery origin. It was found that while dispersal was substantial, many stocked fish stayed in the general area of release (1.8 x 3.2 km) until reaching the age of maturity (~age 3) when they left the estuary, and at all ages they were mixed with wild fish. This suggests that relatively small areas containing the appropriate suite of habitat types could be designated as marine reserves (no-take zones) in order to increase escapement of red drum, thus enhancing recruitment to the spawning stock. Establishing a system of these very small reserves in a number of estuaries would minimize interference with anglers while assisting recovery of red drum stocks, and perhaps enhancing stocks of other estuarine species as well.

Compas, E., B. Clarke, C. Cutler and K. Daish. 2007. Murky waters: Media reporting of marine protected areas in South Australia. Marine Policy. 31:691-697.

Given the public’s limited knowledge of marine environments, informing the public about marine protection presents a unique challenge. Studies have shown a well-informed public is more likely to support environmental issues and that newspapers, in particular, are considered a credible media source. This research investigates media representations of current South Australian efforts to establish a marine protected area (MPA). Articles from five newspapers between 1999 and 2006 were examined for content in the following areas: local marine ecology, the policy process of MPA establishment and stakeholder views. The research found that newspapers concentrated their reporting on opposing stakeholders, opinions and were largely ineffective in conveying the significance of the local marine ecology, the economic benefits of the MPA, and the delayed establishment process. These information gaps have left the public poorly informed, and therefore, there is unlikely to be significant pressure to overcome the continued delays in the establishment process.

 Marine protected areas; Media; Content analysis; South Australia

Cooke, S. J., A. J. Danylchuck, S. E. Danylchuck, C. D. Suski and T. L. Goldberg. 2006. Is catch-and-release recreational angling compatible with no-take marine protected areas? Ocean and Coastal Management. 49:342-354.

Marine protected areas (MPAs) have become a common conservation and management tool for reducing exploitation from the commercial and recreational fisheries sectors. However, the recreational fisheries sector has the potential to be compatible with no-take MPAs when catchand- release angling is practiced because, in theory, no fish are actually harvested. This presumes that the effects of catch-and-release angling and related activities do not cause appreciable declines in fish populations as a result of direct mortality, sub-lethal effects, or indirect effects on fish habitats, or other problems contrary to the goal of a given MPA. Here, we explore the idea that recreational catch-and-release angling may be compatible with some no-take MPAs provided there are no substantive negative ecological consequences. We argue that it is not currently possible to answer definitively the question of whether recreational catch-and-release fisheries can be compatible with no-take MPAs. Mortality rates of released fish vary extensively (between zero and near 100%) and are influenced by a number of factors including environmental conditions, fishing gear, angler behavior, and species-specific characteristics. Nevertheless, research in the field of catch-and-release is beginning to show that certain handling techniques can significantly reduce post-release mortality in fish. With appropriate regulation and angler education, catch-and-release could help enhance conservation and management goals associated with MPAs while maintaining public support and providing alternative tourism-based revenues for displaced fishers. Until sufficient data are available, research should focus on contrasting the fish community characteristics in regions with no fishing and those that permit catch-and-release fishing (i.e., opportunistic observations and controlled manipulations) as well as population-level mathematical modeling to assess the effects of angling on long-term population viability and ecosystem dynamics. Additional efforts should focus on education and outreach that provide anglers and fishing guides with the best available information to reduce catch-and-release mortality, sublethal angling-induced impairments, and broader effects on aquatic environments.

Cooke, S.J. and I.G. Cowx. 2004. The Role of Recreational Fishing in Global Fish Crises. Bioscience 54(9): 857-859.

Exploitation of fishery resources has become a major conservation issue on a global scale. Commercial fisheries have been repeatedly blamed for the worldwide declines in fish populations. However, we contend that the recreational fishing sector also has the potential to negatively affect fish and fisheries. Here we present evidence to show that both recreational and commercial fishing sectors deserve consideration as contributors to the exploitation of fish in marine and inland waters. The lack of global monitoring and compiling of statistics on recreational fishing participation, harvest, and catch-and-release has retarded our ability to understand the magnitude of this fishing sector. Using data from Canada, we estimate that the potential contribution of recreational fish harvest around the world may represent approximately 12 percent of the global fish harvest. Failure to recognize the potential contribution of recreational fishing to fishery declines, environmental degradation, and ecosystem alterations places ecologically and economically important resources at risk. Elevating recreational fishing to a global conservation concern would facilitate the development of strategies to increase the sustainability of this activity.

Costello, C., A. Rassweiler, D. Siegel, G. De Leo, F. Micheli, A. Rosenberg. (2010). The value of spatial information in MPA network design. PNAS Early Edition: 1-6.

We characterize the optimal harvest of a renewable resource in a generalized stochastic spatially explicit model. Despite the complexity of the model, we are able to obtain sharp analytical results. We find that the optimal harvest rule in general depends upon dispersal patterns of the resource across space, and only in special circumstances do we find a modified golden rule of growth that is independent of dispersal patterns. We also find that the optimal harvest rule may include closure of some areas to harvest, either on a temporary or permanent basis (biological reserves). Reserves alone cannot correct open access, but may, under sufficient spatial heterogeneity and connectivity, increase profits if appropriate harvest controls are in place outside of reserves.

Marine reserves; Spatial externalities; Stochastic dynamic programming; Renewable resources; Bioeconomic modeling

Costello, C. and S. Polasky. 2008. Optimal harvesting of stochastic spatial resources. Journal of Environmental Economics and Management. 56:1-18.

We characterize the optimal harvest of a renewable resource in a generalized stochastic spatially explicit model. Despite the complexity of the model, we are able to obtain sharp analytical results. We find that the optimal harvest rule in general depends upon dispersal patterns of the resource across space, and only in special circumstances do we find a modified golden rule of growth that is independent of dispersal patterns. We also find that the optimal harvest rule may include closure of some areas to harvest, either on a temporary or permanent basis (biological reserves). Reserves alone cannot correct open access, but may, under sufficient spatial heterogeneity and connectivity, increase profits if appropriate harvest controls are in place outside of reserves.

Marine reserves; Spatial externalities; Stochastic dynamic programming; Renewable resources; Bioeconomic modeling

Cote, I.M., I. Mosqueira, and J.D. Reynolds. 2001. Effects of marine reserve characteristics on the protection of fish populations: a meta-analysis. Journal of Fish Biology 59(A): 178-189.

Meta-analyses of published data for 19 marine reserves reveal that marine protected areas enhance species richness consistently, but their effect on fish abundance is more variable. Overall, there was a slight (11%) but significant increase in fish species number inside marine reserves, with all reserves sharing a common effect. There was a substantial but non-significant increase in overall fish abundance inside marine reserves compared to adjacent, non-reserve areas. When only species that are the target of fisheries were considered, fish abundance was significantly higher (by 28%) within reserve boundaries. Marine reserves vary significantly in the extent and direction of their response. This variability in relative abundance was not attributable to differences in survey methodology among studies, nor correlated with reserve characteristics such as reserve area, years since protection, latitude nor species diversity. The effectiveness of marine reserves in enhancing fish abundance may be largely related to the intensity of exploitation outside reserve boundaries and to the composition of the fish community within boundaries. It is recommended that studies of marine reserve effectiveness should routinely report fishing intensity, effectiveness of enforcement and habitat characteristics.

Cowen, R. K. and S. Sponaugle 2009. Larval Dispersal and Marine Population Connectivity. Annual Review of Marine Science. 1:443-466.

Connectivity, or the exchange of individuals among marine populations, is a central topic in marine ecology. For most benthic marine species with complex life cycles, this exchange occurs primarily during the pelagic larval stage. The small size of larvae coupled with the vast and complex fluid environment they occupy hamper our ability to quantify dispersal and connectivity. Evidence from direct and indirect approaches using geochemical and genetic techniques suggests that populations range from fully open to fully closed. Understanding the biophysical processes that contribute to observed dispersal patterns requires integrated interdisciplinary approaches that incorporate high-resolution biophysical modeling and empirical data. Further, differential postsettlement survival of larvae may add complexity to measurements of connectivity. The degree to which populations self recruit or receive subsidy from other populations has consequences for a number of fundamental ecological processes that affect population regulation and persistence. Finally, a full understanding of population connectivity has important applications for management and conservation.

Craig, M. T., F. J. Fodrie, P. A. Hastings. (2004). The Nearshore Fish Assemblage of the Scripps Coastal Reserve, San Diego, California. Coastal Management 32: 341-351.

Marine reserves are quickly becoming a primary tool in the management of coastal resources worldwide. With a growing demand for appropriate management strategies and enforcement of existing regulations, an urgent need has developed to obtain baseline data for regional faunal assemblages. In an attempt to develop a comprehensive list of fishes for one of California's southernmost marine reserves, nearshore marine species were qualitatively sampled within the Scripps Coastal Reserve (SCR). Overall, 59 species representing 31 families were recorded during the calendar year 2002. The fish assemblage of the SCR was dominated by species typical of soft bottom communities in southern California as well as several pelagic, rocky reef, and intertidal species. The most abundant species was the speckled sanddab, Citharichthys stigmaeus. Many species were represented by juvenile or young-of-the-year age classes, while adults of C. stigmaeus were present in reproductively active stages throughout the study. The numerous habitat types within the Scripps Coastal Reserve support a diverse fish assemblage within a relatively small area and includes essential habitat and nursery grounds for several species of nearshore fishes. These data support the idea that incorporating habitat diversity as a variable in reserve design may serve to increase the function of proposed reserves.

Citharichthys stigmaeus, Marine Reserves, MPA, near-shore fishes

Crain, C. M., K. Kroeker and B. S. Halpern. 2008. Interactive and cumulative effects of multiple human stressors in marine systems. Ecology Letters. 11:1304-1315.

Humans impact natural systems in a multitude of ways, yet the cumulative effect of multiple stressors on ecological communities remains largely unknown. Here we synthesized 171 studies that manipulated two or more stressors in marine and coastal systems and found that cumulative effects in individual studies were additive (26%), synergistic (36%), and antagonistic (38%). The overall interaction effect across all studies was synergistic, but interaction type varied by response level (community: antagonistic, population: synergistic), trophic level (autotrophs: antagonistic, heterotrophs: synergistic), and specific stressor pair (seven pairs additive, three pairs each synergistic and antagonistic). Addition of a third stressor changed interaction effects significantly in two-thirds of all cases and doubled the number of synergistic interactions. Given that most studies were performed in laboratories where stressor effects can be carefully isolated, these three-stressor results suggest that synergies may be quite common in nature where more than two stressors almost always coexist. While significant gaps exist in multiple stressor research, our results suggest an immediate need to account for stressor interactions in ecological studies and conservation planning.

Antagonisms; cumulative stressors; cumulative threat models; ecosystem-based management; interactions; synergisms; threat-analysis

Cudney-Bueno, R., M. F. Lavin, S. G. Marinone, P. T. Raimondi and W. W. Shaw. 2009. Rapid effects of marine reserves via larval dispersal. Public Library of Science One. 4:1-7.

Marine reserves have been advocated worldwide as conservation and fishery management tools. It is argued that they can protect ecosystems and also benefit fisheries via density-dependent spillover of adults and enhanced larval dispersal into fishing areas. However, while evidence has shown that marine reserves can meet conservation targets, their effects on fisheries are less understood. In particular, the basic question of if and over what temporal and spatial scales reserves can benefit fished populations via larval dispersal remains unanswered. We tested predictions of a larval transport model for a marine reserve network in the Gulf of California, Mexico, via field oceanography and repeated density counts of recently settled juvenile commercial mollusks before and after reserve establishment. We show that local retention of larvae within a reserve network can take place with enhanced, but spatially-explicit, recruitment to local fisheries. Enhancement occurred rapidly (2 yrs), with up to a three-fold increase in density of juveniles found in fished areas at the downstream edge of the reserve network, but other fishing areas within the network were unaffected. These findings were consistent with our model predictions. Our findings underscore the potential benefits of protecting larval sources and show that enhancement in recruitment can be manifested rapidly. However, benefits can be markedly variable within a local seascape. Hence, effects of marine reserve networks, positive or negative, may be overlooked when only focusing on overall responses and not considering finer spatially-explicit responses within a reserve network and its adjacent fishing grounds. Our results therefore call for future research on marine reserves that addresses this variability in order to help frame appropriate scenarios for the spatial management scales of interest.

Dalton, T. M. 2005. Beyond biogeography: a framework for involving the public in planning of U.S. marine protected areas. Conservation Biology. 19:1392-1401.

Planning of marine protected areas (MPAs) is highlighted in the conservation literature but is not explored in much detail. Many researchers acknowledge the importance of involving the public in MPA planning, but there is limited guidance on how to do this in an effective manner. I present a framework for involving the public in planning of U.S. MPAs. Derived from empirically and theoretically based research on public participation in U.S. natural resource management, this framework is composed of factors that influence the success of participatory processes: active participant involvement, complete information exchange, fair decision making, efficient administration, and positive participant interactions. Processes incorporating these factors will produce decisions that are more likely to be supported by stakeholders, meet management objectives, and fulfill conservation goals. This framework contributes to the MPA social science literature and responds to calls in the conservation literature to increase the use of social science research to inform conservation decision making.

 Ecosystem-based management; governance of marine protected areas; public participation; stakeholder involvement

Dalton, M.T. 2004. An approach for integrating economic impact analysis into the evaluation of potential marine protected area sites. Journal of Environmental Management 70(3): 333-349.

Marine protected areas (MPAs) are one tool that can be used in the comprehensive management of human activities in areas of the ocean. Although researchers have supported using MPAs as an ecosystem management tool, scientific research on MPAs in areas other than fisheries and fisheries management is limited. This paper presents a model for designing marine protected areas that protect important components of the ecosystem while minimizing economic impacts on local communities. This model combines conservation principles derived specifically for the marine environment with economic impact assessment. This integrated model allows for consideration of both fishery and non-fishery resources and activities such as shipping and recreational boating. An illustration of the model is presented that estimates the total economic impacts on Massachusetts' coastal counties of restricting fishing and shipping at certain sites in an area in the southern Gulf of Maine. The results suggest that the economic impacts on the region would differ according to the site in which shipping and fishing were restricted. Restricting activities in certain sites may have considerable impacts on local communities. The use of the model for evaluating and comparing potential MPA sites is illustrated through an evaluation of three different policy scenarios. The scenarios demonstrate how the model could be used to achieve different goals for managing resources in the region: protecting important components of the ecosystem, minimizing economic impacts on the local region, or a combination of the two.

Dayton, P.K., E. Sala, M.J. Tegner and S. Thrush. 2000. Marine reserves: Parks, baselines, and fishery enhancement. Bulletin of Marine Science 66(3): 617-634.

Coastal zones are usually managed with two main objectives: (1) conservation/maintenance of biodiversity and intrinsic ecosystem services and (2) maintenance of sustainable fisheries. The management needs that can be met with marine protected areas fall into corresponding categories. First, fully protected (that is, no-take) reserves--parks--offer banchmarks and protect ecosystem integrity while encouraging research, education, and aesthetic appreciation of nature. Second, by allowing focused local control of human impacts, marine protected areas can be used to focus more intense local management designed to increase yield and allow research to help define sustainability and protect against uncertainty by using carefully managed fisheries as a research tool. We have been gambling with the future by establishing a poor balance between short-term profit and long-term risks. The absence of meaningful, fully protected reserves has produced a situation in which there are virtually no areas north of the Antarctic in the world's oceans that have exploitable resources where scientists can study natural marine systems. In most areas the higher-order predators and many other important species have been virtually eliminated; many benthic habitats have been much changed by fishing activities. Without solid data documenting changes through time, the relative merits of various causes and effects that operate in complex ecological systems can always be argued. Without natural systems important questions cannot be studied--for example, how the ecosystem roles of various species can be assessed, how they can be managed in a sustainable manner, and how we can evaluate resilience or relative rates of recovery.

Denny, C. M. and R. C. Babcock. 2004. Do partial marine reserves protect reef fish assemblages? Biological Conservation. 116:119-129.

Fish assemblages in the Mimiwhangata Marine Park, an area closed to commercial fishing but open to most forms of recreational fishing, were compared with adjacent fished areas. Two survey methodologies were used; baited underwater video and underwater visual census. Snapper (Pagrus auratus), the most heavily targeted fish species in the region, showed no difference in abundance or size between the Marine Park and adjacent control areas. When compared to the fully no-take Poor Knights Island Marine Reserve and two other reference areas open to all kinds of fishing (Cape Brett and the Mokohinau Islands), the abundance and size of snapper at the Marine Park were most similar to fished reference areas. In fact, the Marine Park had the lowest mean numbers and sizes of snapper of all areas, no-take or open to fishing. Baited underwater video found that pigfish (Bodianus unimaculatus), leatherjackets (Parika scaber) and trevally (Pseudocaranx dentex) were significantly more common in the Marine Park, than in the adjacent control areas. However, none of these species are heavily targeted by fishers. Underwater visual census found similar results with five species significantly more abundant in the Marine Park and five species more abundant outside the Marine Park. The lack of any recovery by snapper within the Marine Park, despite the exclusion of commercial fishers and restrictions on recreational fishing, indicates that partial closures are ineffective as conservation tools. The data suggest fishing pressure within the Marine Park is at least as high as at other ‘fished’ sites.

 Marine protected area; Mimiwhangata Marine Park; Pagrus auratus; Snapper; New Zealand; Gear restrictions

Diaz, D., M. Zabala, C. Linares, B. Hereu and P. Abello. 2005. Increased predation of juvenile European spiny lobster (Palinurus elephas) in a marine protected area. New Zealand Journal of Marine and Freshwater Research. 39:447-453.

One of the aims of Mediterranean marine protected areas (MPAs) is to increase populations of exploited species, such as the European spiny lobster (Palinurus elephas), which is considered a key species for its commercial and ecological value. Monitoring of temporal patterns in abundance of early benthic stages of P. elephas indicated that predation may be higher inside the Medes Islands MPA relative to adjacent control sites. Tethering experiments were performed to test whether predation rates actually differed within and outside the MPA. Relative mortality of recently-settled juveniles inside the MPA was much higher than in control sites in adjacent non-protected areas. Treatments with and without shelter indicated that predation on recently-settled juvenile spiny lobsters was moderated by the availability of suitable shelter. The decline or absence of fish predators in the fished area may be the reason why juvenile lobsters outside the MPA experience lower predation than within the MPA.

Predation; Palinurus elephas; marine protected areas; spiny lobster; shelter; Mediterranean Sea

Edgar, G. J., N. S. Barrett and R. D. Stuart-Smith. 2009. Exploited reefs protected from fishing transform over decades into conservation features otherwise absent from seascapes. Ecological Applications. 19:1967-1974.

Tasmanian reef communities within 'no-take' marine protected areas (MPAs) exhibited direct and indirect ecological changes that increasingly manifested over 16 years, eventually transforming into communities not otherwise present in the regional seascape. Data from 14 temperate and subtropical Australian MPAs further demonstrated that ecological changes continue to develop in MPAs over at least two decades, probably much longer. The continent-scale study additionally showed recently established MPAs to be consistently located at sites with low resource value relative to adjacent fished reference areas. This outcome was presumably generated by sociopolitical pressures and planning processes that aim to systematically avoid locations with valuable resources, potentially compromising biodiversity conservation goals. Locations that were formerly highly fished are needed within MPA networks if the networks are to achieve conservation aims associated with (1) safeguarding all regional habitat types, (2) protecting threatened habitats and species, and (3) providing appropriate reference benchmarks for assessing impacts of fishing. Because of long time lags, the ubiquity of fishing impacts, and the relatively recent establishment of MPAs, the full impact of fishing on coastal reefs has yet to be empirically assessed.

Australia; effects of fishing; long-term monitoring; marine protected area; reef fishes; sea urchins; temperate and subtropical reefs; threatened species; trophic cascades

Fanshawe, S., G.R. Vanblaricom and A. A. Shelly. 2003. Restored top carnivores as detriments to the performance of marine protected areas intended for fishery sustainability: a case study with red abalones and sea otters. Conservation Biology. 17:273-283.

Marine protected areas are possible solutions to the problems of protecting the integrity of marine ecosystems and of sustaining harvested marine populations. We report demographic data for red abalones (Haliotis rufescens) at nine sites along the California coast. Six of our sites are within marine protected areas, and four of those six sites are occupied by sea otters (Enhydra lutris). Sea otters are known abalone predators and are believed to have an important role in facilitating biodiversity within coastal kelp forest communities along the North Pacific Rim. We asked whether marine protected areas intended to conserve ecosystems are compatible with use of marine protected areas for abalone fishery sustainability. We found that both sea otters and recreational harvest alter the density, size distribution, and microhabitat distribution of red abalones in qualitatively similar ways. Red abalone populations in marine protected areas outside the current sea otter range have higher density, are composed of larger individuals, and occur in moreopen microhabitats compared with populations in locations lacking sea otters but subject to harvest and with populations in locations with sea otters. The effects of sea otters are stronger than the effects of harvest. Characterization of harvest effects on density may be confounded by other uncontrolled factors. We conclude that coastal marine protected areas off California cannot enhance abalone fisheries if, in the interest of ecosystem integrity, they also contain sea otters. Where restored top carnivores limit the sustainability of commodity harvest, it may be possible to resolve conflicts with two categories of spatially segregated, single-use marine protected areas, one focusing on ecosystem restoration and the other on fishery development.

Fenberg, P. B. and K. Roy. 2008. Ecological and evolutionary consequences of size-selective harvesting: how much do we know? Molecular Ecology. 17:209-220.

Size-selective harvesting, where the large individuals of a particular species are preferentially taken, is common in both marine and terrestrial habitats. Preferential removal of larger individuals of a species has been shown to have a negative effect on its demography, life history and ecology, and empirical studies are increasingly documenting such impacts. But determining whether the observed changes represent evolutionary response or phenotypic plasticity remains a challenge. In addition, the problem is not recognized in most management plans for fish and marine invertebrates that still mandate a minimum size restriction. We use examples from both aquatic and terrestrial habitats to illustrate some of the biological consequences of size-selective harvesting and discuss possible future directions of research as well as changes in management policy needed to mitigate its negative biological impacts.

fishery; invertebrates; macroevolution; microevolution; size-selective harvesting; terrestrial vertebrates

Fernandez, M. and J. C. Castilla. 2005. Marine conservation in Chile: historical perspective, lessons, and challenges. Conservation Biology. 19.

Chile is one of the world’s leading countries in landings (catch) of marine resources. The pioneer studies of human impacts on coastal marine communities provided the scientific basis on which to establish novel resource management strategies for exploited wild populations but were not used to develop a comprehensive marine conservation plan that would also include no-take areas. We reviewed the development of marine conservation actions since approximately 1970 to date, focusing on the (1) complex legal framework for establishment of marine protected areas, (2) scientific grounds that provided the impetus to establish areas where exploitation is regulated, (3) private efforts that were critical to creating the first marine protected areas, and (4) lessons and constraints derived from this process as well as the challenges ahead. The existing legal tools for the protection of the ocean include natural sanctuaries, marine reserves, marine parks, national monuments, and management and exploitation areas for benthic resources. These instruments may be applied in coastal marine protected areas. It is remarkable that most of the existing marine protected areas in Chile are sponsored and administered by private organizations. We think the sequence in which the development of the different conservation instruments occurred, with a high priority reserved for initiatives tending to promote exploitation of the ocean (aquaculture and fisheries), poses challenges and constraints for establishing a network of marine protected areas that combine such apparently diametrically opposing goals as exploitation and preservation of marine species. More recently, the value of preserving biodiversity became evident with the creation of the first marine parks. We encourage more scientific information on patterns of biodiversity, biological processes, and assessment of human impact to be incorporated in the process to reach the goal of preserving 10% of the representative marine habitats along Chile’s coast.

 Management areas; marine parks; marine protected areas

Field, J. C., A. E. Punt, R. D. Methot and C. J. Thomson. 2006. Does MPA mean 'Major Problem for Assessments'? Considering the consequences of place-based management systems. Fish and Fisheries. 7:284-302.

Marine protected areas (MPAs) have been increasingly proposed, evaluated and implemented as management tools for achieving both fisheries and conservation objectives in aquatic ecosystems. However, there is a challenge associated with the application of MPAs in marine resource management with respect to the consequences to traditional systems of monitoring and managing fisheries resources. The place-based paradigm of MPAs can complicate the population-based paradigm of most fisheries stock assessments. In this review, we identify the potential complications that could result from both existing and future MPAs to the science and management systems currently in place for meeting conventional fisheries management objectives. The intent is not to evaluate the effects of implementing MPAs on fisheries yields, or even to consider the extent to which MPAs may achieve conservation oriented objectives, but rather to evaluate the consequences of MPA implementation on the ability to monitor and assess fishery resources consistent with existing methods and legislative mandates. Although examples are drawn primarily from groundfish fisheries on the West Coast of the USA, the lessons are broadly applicable to management systems worldwide, particularly those in which there exists the institutional infrastructure for managing resources based on quantitative assessments of resource status and productivity.

Fisheries assessment; fisheries management; fish stock; marine protected area; spatial model

Fisher, J. A. and K. T. Frank. 2004. Abundance-distribution relationships and conservation of exploited marine fishes. Marine Ecology Progress Series. 279:201-213.

The effects of human exploitation on macroecological patterns have received little attention, although such investigations may highlight unique spatial and temporal changes characteristic of species and assemblages subject to persistent disturbance. In unexploited systems (mainly among temperate avifauna) positive relationships between local abundance and geographic distribution are prevalent for individual species through time (intraspecific pattern) and among species during fixed time periods (interspecific pattern). We investigated intraspecific and interspecific relationships for 24 common marine fishes on the Scotian Shelf and Bay of Fundy, Canada, some of which have been commercially exploited for several decades. Based on extensive fisheries-independent trawl survey data from 1970 to 2001, 16 of the 34 stocks, comprising 13 species, exhibited significant positive intraspecific relationships. Significant relationships were associated mainly with those stocks that demonstrated significant temporal trends in both abundance and geographic distribution. The time-averaged (32 yr) interspecific relationship was positive and significant at the largest scale examined. Significant annual interspecific relationships were also detected over 26 yr. Surprisingly, the slopes of the annual relationships increased systematically and doubled through time, probably due to size-selective exploitation, shifting target species, and associated species interactions. In contrast to previous studies, our results indicate that the contributions of individual species to the interspecific relationship can change through time, and these changes dramatically alter the interspecific  abundance–distribution relationship. Temporal trends in the interspecific relationship have not previously been reported, and appear to be due to the large spatial- and temporal-scale effects of exploitation.

Exploited fisheries; Geographical range; Macroecology; Management; Marine protected area; MPA; Marine reserve; Range contraction; Scotian Shelf

Fisher, R., S. M. Sogard and S. A. Berkeley. 2007. Trade-offs between size and energy reserves reflect alternative strategies for optimizing larval survival potential in rockfish. Marine Ecology Progress Series. 344:2657-270.

Reproductive strategies balancing offspring size and offspring number have been well documented in empirical tests of life-history theory. Here we found an additional trade-off between offspring size and offspring condition. Among 5 species of live-bearing rockfishes (Sebastes spp.) from central Californian populations, we observed a negative relationship between larval length at parturition and the size of their oil globule (a triacylglycerol-rich energy reserve). When compared with a variety of performance variables (resistance to starvation, growth, startle-escape performance and routine activity levels), it appears that this trade-off leads to a conflict when trying to optimize survival potential, with differing benefits to each trait. A large oil globule greatly increases resistance to starvation, whereas larger body size is associated with numerous performance benefits likely to synergistically decrease predation-based mortality and increase success at capturing prey (increased startle speeds and distances, as well as more rapid onset of growth and larger size at age). The tradeoff between energy reserves and body size is further reflected in the seasonal patterns of parturition of the 5 species, with larvae having large oil globules and small body size being released in winter, when productivity in the California Current is low but transport is generally onshore, and those with small oil globule reserves and large body size released in late spring, when productivity is high but transport is generally offshore. These 2 apparent reproductive strategies also reflect subgeneric phylogenetic relationships, suggesting a potential lineage-specific basis for the contrast in larval traits. The results highlight the importance of measuring both physical and performance traits of larvae, as well as considering multiple attributes of both, when evaluating progeny quality.

Life history trade-offs; Offspring size; Larval performance traits; Sebastes

Fodrie, F. J. and L. A. Levin. (2008). Linking juvenile habitat utilization to population dynamics of California halibut. Limnology and Oceanography 53(2): 799-812.

We investigated the nursery role of four coastal ecosystems for the California halibut (Paralichthys californicus) using the following metrics: (1) contribution in producing the fish that advance to older age classes, (2) connectivity of coastal systems resulting from migration of fish from juvenile to subadult habitats, and (3) effect of nursery habitat usage and availability on subadult population size, specifically evaluating the concentration hypothesis. Potential nurseries were grouped using a robust classification scheme that segregated exposed, bay, lagoon, and estuarine environments. Assignment of nursery origins for individual subadult fish via elemental fingerprinting indicated that exposed coasts, bays, lagoons, and estuaries contributed 31%, 65%, 1%, and 3% of advancing juvenile halibut during 2003, versus 49%, 33%, 16%, and 2% during 2004, respectively. These results were remarkably similar to ''expected'' nursery contributions derived from field surveys, suggesting that in this system juvenile distributions were a good indicator of unit-area productivity of juvenile habitats and that density dependent mechanisms during the juvenile phase did not regulate recruitment pulses. Elemental fingerprinting also demonstrated that individuals egressing from bays did not migrate far from their nursery origins (,10 km), resulting in reduced connectivity along the 110-km study region over the timescale of approximately one generation. Consequently, we observed considerably higher subadult densities at sites near large bays, while populations distant from large bays appeared to be more influenced by nursery habitat limitation. Over large (,100 km) scales, the location and availability of nursery habitat alternatives had significant effects on the population dynamics of an important member of the ichthyofaunal community of southern California.

California halibut, nursery role, coastal ecosystem

Follesa, M., D. Cuccu, R. Cannas, A. Sabatini and A. Cau. 2007. Emigration and retention of Palinurus elephas (Fabricius, 1787) in a central western Mediterranean marine protected area. Scientia Marina. 71:279-285.

This study describes the results obtained by applying the Arnason Schwartz multistate mark-recapture model to eight years of data collected in and around a small no-fishing marine protected area (MPA; 4 km2) in the central western Mediterranean. From 1997 to 2004, a total of 4044 specimens of Palinurus elephas (Fabr., 1787) were tagged and 317 recaptured. The most parsimonious model which best explained the data variability was that of a temporally constant rate of apparent survival and movement in each of the two strata. The absence of any temporal influence in the apparent survival rate inside the no-take area suggested that spillover and mortality are constant for each period of the study. The lower apparent survival rate in surrounding zones than inside the MPA (0.26 ± 0.04 (SE) vs 0.94 ± 0.03 (SE)) is presumed to be a function of fishing effort. A continuous movement of P. elephas across the boundary of the small MPA was also tested. This information on retention of lobsters in the MPA contributes to our understanding of the effect of introducing MPAs into a managed commercial fishery system.

multistate models; survival estimation; movements; spiny lobster; central western Mediterranean

Follesa, M. C., D. Cuccu, R. Cannas, S. Cabiddu, M. Murenu, A. Sabatini and A. Cau. 2008. Effects of marine reserve protection on spiny lobster (Palinurus elephas Fabr., 1787) in a central western Mediterranean area. Hydrobiologica. 606:63-68.

The contribution that a small restocking area (central western Mediterranean) has made to the Palinurus elephas (Fabr., 1787) population was examined by comparing the abundances recorded inside and outside the area before (1997) and after the establishment of the reserve (1998-2005). From 1998 to 2002 a progressive percentage increase of P. elephas biomass values was recorded both inside the area and in the surrounding zones. The total mean abundance within the reserve (CPUE = 0.23 ± 0.10 kg/50 m/boat) was 7.5 times greater than that for the neighbouring zone (CPUE = 0.03 ± 0.07 kg/50 m/boat). The inter-annual analysis of lobster size inside the area also showed a progressive increase of adults and juveniles. The results highlighted the effectiveness of fishing restrictions in rebuilding the lobsters population and suggest that small MPAs should be set up.

Spiny lobster; Palinurus elephas; Marine reserve area; Central western Mediterranean

Forcada, A., C. Valle, P. Bonhomme, G. Criquet, G. Cadiou, P. Lenfant and J. L. Sanchez-Lizaso. 2009.Effects of habitat on spillover from marine protected areas to artisanal fisheries. Marine Ecology Progress Series. 379:197-211.

Marine protected areas (MPAs) potentially enhance the long-term sustainability of coastal fish resources that have been overexploited. The types and quality of habitats, both inside and outside the MPAs, may determine the likelihood of migration by fish to surrounding unprotected areas where spillover to fisheries occurs. We assessed whether MPAs enhanced catches of artisanal fisheries, using an experimental fishing study with the same fishing gear as that used by local fishers. This approach allowed us to test the hypothesis of increased catches along the borders of MPAs in comparison with those in other fishing grounds located at medium and far distances from 3 Mediterranean MPAs: Tabarca Marine Reserve, Carry-le-Rouet Marine Reserve and Cerbère-Banyuls Marine Reserve. Surveys were done over 2 homogeneous habitats (Posidonia oceanica meadow and sand), in 3 different seasons. Catches were significantly higher for some species near the borders of the MPAs when fishing on P. oceanica meadows, but not when fishing on sandy bottoms. The spillover effect appears to be limited by a lack of continuous suitable habitat through the boundaries of the MPA. Some of the species that showed a significant response to protection and concurrent higher catches near the MPA borders, such as Dentex dentex, Mullus surmuletus, Phycis phycis, Sciaena umbra and Scorpaena porcus, are target species of artisanal fisheries. Although we found that the spatial scale of the spillover-induced density gradient was localized, it was sufficient to provide local benefits to artisanal fisheries. We conclude that spillover effects are not a universal consequence of siting MPAs in temperate waters and that they are related to the distribution of habitats inside and around MPAs.

MPA; Export production; Artisanal fisheries; Fish; Habitat connectivity; Spillover; Mediterranean Sea

Forde, S. E. 2002. Modelling the effects of an oil spill on open populations of intertidal invertebrates. Journal of Applied Ecology. 39:595-604.

  1. Knowledge of the impact of oil spills on coastal communities, in California and elsewhere, is currently limited by a lack of long-term data, the inability to infer causality from monitoring studies, and the necessarily limited spatial and temporal scales of experimental studies.
  2. This study therefore used a modelling approach to investigate the combined effects of different intensities of an oil spill and recruitment variation on a barnacle Chthamalus fissus population. The methodology and results are likely to apply to any similarly open marine populations with dispersive larval forms.
  3. The model consisted of a source population comprising individuals that reproduced based on size and probability of mortality. Larvae from the source population entered a larval pool. A proportion of the larvae from the larval pool recruited to a focal population within the region.
  4. The model was used to assess the effects on recruitment to the focal population of (i) the size structure of the source population, (ii) the intensity of oil spills in the source population, and (iii) recruitment intensity to the focal population.
  5. Differences in the size structure of the source population had little effect on the reproductive output of the population relative to the intensity of the oil spill. Similarly, the intensity of the oil spill had a stronger influence on recruitment to the focal population than the size structure of the source population. Size structure of the source population was important, however, when evaluating the seasonal trajectory of the focal population.
  6. Modelling provides a format in which questions about the effects of human impacts can be addressed that would be intractable using experiments. The results of this model suggest that recruitment variation, along with the processes underlying recruitment variation, are critical to predicting the effects of disturbance on open marine populations.

Barnacle; Chthamalus fissus; disturbance; individual-based model; life history; population model; rocky intertidal

Francis, R. C., M. A. Hixon, M. E. Clarke, S. A. Murawski and S. Ralston. 2007. Ten commandments for ecosystem-based fisheries scientists. Fisheries. 32:217-233.

In an effort to accelerate the ongoing paradigm shift in fisheries science from the traditional single-species mindset toward more ecosystem-based approaches, we offer the following “commandments” as action items for bridging the gap between general principles and specific methodologies.

  1. Keep a perspective that is holistic, risk-averse, and adaptive.
  2. Question key assumptions, no matter how basic.
  3. Maintain old-growth age structure in fish populations.
  4. Characterize and maintain the natural spatial structure of fi sh stocks.
  5. Characterize and maintain viable fish habitats.
  6. Characterize and maintain ecosystem resilience.
  7. Identify and maintain critical food web connections.
  8. Account for ecosystem change through time.
  9. Account for evolutionary change caused by fishing.
  10. Implement an approach that is integrated, interdisciplinary, and inclusive.

Although the shift in worldview embodied in these commandments can occur immediately without additional funding, full implementation of ecosystem-based fisheries science will require an expanded empirical basis as well as novel approaches to modeling. We believe that pursuing these action items is essential for productive marine fisheries to become truly sustainable for present and future generations.

Frank, K.T., N.L. Shackell, and J.E. Simon. 2000. An evaluation of the Emerald/Western Bank juvenile haddock closed area. ICES Journal of Marine Science. 57: 1023-1034.

A juvenile haddock (Melanogrammus aeglefinus) closed area was established on the offshore banks (Emerald and Western) of the central Scotian Shelf (NAFO Div. 4W) in 1987. The management objective associated with this meausre was to protect incoming recruits and thereby allow the stock to rebuild. Our evaluation of the effectiveness of the closed area revealed that the management objective was not fully met. The expected trend of declining juvenile mortality after, and high mortality preceding its imposition, was not readily apparent. The lack of response may have been due to several factors: (i) the proportion of juveniles within the closed area steadily declined and a majority of year classes during the post-closure period remained unprotected; (ii) the closed area remained open to fishing by fixed gear whose catches inside the closed area and surrounding areas steadily increased; and (iii) the resident haddock stock deteriorated in terms of growth and condition due to a combination of historical over-exploitation and large-scale environmental changes. The closed area does appear to have had some benefit to other groundfish species in terms of increased abundance, notably American plaice (Hippoglossoides americanus) and winter flounder (Pseudopleuronectes americanus).

Fraschetti, S., A. Terlizzi, F. Micheli, L. Benedetti-Cecchi and F. Boero. 2002. Marine protected areas in the Mediterranean Sea: Objectives, effectiveness and monitoring. Marine Ecology. 23:190-200.

The number of Marine Protected Areas (MPAs) is continuously increasing worldwide because of the increasing recognition of the profound effects that humans can have on marine systems. A large body of literature deals with marine reserves and their potential as conservation and management tools. In several cases, empirical evidence demonstrated that reserves can harbour greater diversity, higher abundance, and larger organisms than unprotected areas. In most cases, however, reserve design and site selection involved little scientific justification, with no direct test of most of the mechanisms assumed to work in a marine reserve. Field investigations of subtidal marine reserves are generally confounded by intrinsic ecological differences between sites investigated inside and outside reserves, by a lack of site and reserve replication, or by the absence of information about the biota before reserve establishment. This is particularly true in the Mediterranean Sea. The aim of this paper is to show that, at least in the Mediterranean basin, the effectiveness of MPAs has been rarely demonstrated because of lack of appropriate sampling designs. An MPA can be considered as a zone subjected to human impact, presumably a positive one. As a consequence, we propose the use of experimental procedures generally utilised for detecting environmental impacts.

Fraschetti, S., P. D'Ambrosio, F. Micheli, F. Pizzolante, S. Bussotti and A. Terlizzi. 2009. Design of marine protected areas in a human-dominated seascape. Marine Ecology Progress Series. 375:13-24.

Conservation of the Mediterranean marine ecosystems is particularly challenging; high biodiversity is combined with high human population densities and a long history of resource exploitation. Residents and users of coastal areas often perceive marine conservation and management as limiting factors to economic development. Under these conditions, the creation of comprehensive systems of marine protected areas (MPAs) can be problematic. We selected a stretch of coast in southern Italy as a representative example of a Mediterranean coastline and nearshore marine ecosystems, featuring a complex matrix of vulnerable habitats in a landscape fragmented by multiple human activities and associated stressors. Through the use of site-selection algorithms, we investigated how human activities constrain MPA planning. Rather than assuming that patches of the same habitat found at different locations are interchangeable, we considered the scenario of a heterogeneous landscape of human impacts creating high variability in habitat quality. Despite widespread human influence, identification of portions of habitats to be protected from direct human disturbance as core no-take areas is still possible using the inclusion of 10 and 30% of low and high priority habitat, respectively, in reserves as a conservation target. Implementation of MPAs with a limited protection scheme that also include several small no-take areas could represent a feasible strategy for the conservation of Mediterranean coastal marine habitats. Moreover, MPAs could be combined with coastal zoning of activities as a means of further controlling effects over broader areas and allowing for recovery of degraded areas. Site-selection algorithms are invaluable tools for conservation planning. However, careful consideration of the potential constraints imposed by local human activities and future research aimed at filling existing gaps in understanding the ecology are crucial for making this approach useful in marine conservation planning.

Marine protected areas; Human impacts and constraints; Biodiversity; MARXAN; Mediterranean Sea; Site-selection algorithms; Marine seascapes; MPA networks

Freeman, D., A. B. MacDiarmid and R. B. Taylor. 2009.Habitat patches that cross marine reserve boundaries: consequences for the lobster Jasus edwardsii. Marine Ecology Progress Series. 388:159-167.

The spatial configuration of marine reserves should reflect management objectives. If reserves are intended to conserve 'natural' biological communities, then reserve boundaries should follow barriers to species movement, but if cross-boundary movement of harvestable individuals associated with certain habitat is desired for fisheries purposes, then boundaries should intersect that habitat. We relate movement patterns of the reef-associated spiny lobster Jasus edwardsii (Palinuridae) to the relative positions of habitat and reserve boundaries in a 24.5 km2 marine reserve on the temperate northeast coast of New Zealand by tagging >5000 individuals and recapturing a subset over 3 yr using pots. Lobster movement patterns were sex- and size-dependent, but nearly all recaptured individuals were found on the same rocky reef on which they were tagged, indicating that lobsters were reluctant to cross the muddy sediments between reefs. Lobsters became increasingly likely to migrate from the reserve into the heavily fished adjacent coast as the proportion of their reef that was unprotected increased. Corresponding changes in average catch per unit effort (CPUE) and size of all lobsters (tagged and untagged) occurred within the protected parts of the reefs, with lobster densities on a fully protected reef being 8-fold higher than densities on the protected part of a reef that was 91% unprotected.

Exploited species; Habitat boundary; Tag-recapture; Marine protected areas

Froeschke, J. T., L. G. Allen and D. J. Pondella II. 2006. The Fish Assemblages Inside and Outside of a Temperate Marine Reserve in Southern California. Bulletin, Southern California Academy of Sciences. 105:128-142.

The purpose of this investigation was to evaluate the effect of a small marine reserve (established 1988) on a temperate rocky reef fish assemblage at Santa Catalina Island, California. Fish surveys on SCUBA were conducted at two reserve and two non-reserve sites from October 2002 to January 2004. Sites were similar in fish density, species richness and biomass of the entire fish assemblage. However, the adult densities of two important fishery species, California sheep-head (Semicossyphus pulcher; 7.6 ±0.5 and 5.5 ±0.4/100 m2 inside versus outside) and kelp bass (Paralabrax clathratus; 3.6 ±0.4 and 2.9 ±0.4 inside versus outside), were significantly higher within the reserve. The reserve appears to be effective in increasing density and biomass of two impacted species that were readily observed and surveyed on SCUBA.

Gaines, S.D., B. Gaylord, and J.L. Largier. 2003. Avoiding Current Oversights in Marine Reserve Design. Ecological Applications 13(1) Supplement: S32-S46

The pun in the above title reflects two points. First, marine life cycles commonly include a dispersive juvenile stage that is moved about by ocean currents. This stage often is the predominant, or only, means of dispersal that connects spatially disjunct populations. As a consequence, details of dispersal likely play a critical role in determining the effectiveness of marine reserves as a management and conservation tool. Curiously, however (and this is the second point of the title), although dozens of models for marine reserves now exist, few actually account explicitly for larval dispersal. Moreover, those that do include dispersal, do so almost exclusively by considering it to be a nondirectional spreading process (diffusion), ignoring the effects of directional transport by currents (advection). Here we develop a population dynamical model for marine organisms with relatively sedentary adults whose larvae are transported in a simple flow field with both diffusive spreading and directional characteristics. We find that advection can play a dominant role in determining the effectiveness of different reserve configurations. Two of the most important consequences are: (1) with strong currents, multiple reserves can be markedly more effective than single reserves of equivalent total size; and (2) in the presence of strong currents, reserves can significantly outperform traditional, effort-based management strategies in terms of fisheries yield, and do so with less risk. These results suggest that successful reserve design may require considerable new efforts to examine explicitly the role of dispersal of young.

Gardmark, A., N. Jonzen and M. Mangel. 2006. Density-dependent body growth reduces the potential of marine reserves to enhance yields. Journal of Applied Ecology. 43:61-69.

  1. Some models of marine no-take reserves predict that reserves can enhance fishery yield. However, empirical evidence of this remains inconclusive. One reason for this may be the disregard for density-dependent body growth in most models. Density-dependent body growth links the number and size of individuals, and thus could influence the biomass of fishery yield.
  2. We developed an age- and size-structured model of an exploited population and analysed the effect of implementing a no-take reserve of varying size.
  3. Protecting part of a population from exploitation in a no-take reserve results in a rapid build-up of biomass inside the reserve because of increased survival.  However, when body growth is density-dependent it also results in reduced length at a given age within the no-take reserve because of crowding effects. This prediction is backed up by empirical observations.
  4. If there is export of individuals (here larvae) from the no-take reserve, length at a given age will also decrease in the fished part of the population outside the  reserve. An increase in the number of exploitable individuals thus results in decreased individual body mass. The positive effect of larval drift on fished population size and catch numbers will therefore rarely translate into an increase in equilibrium yield biomass.
  5. Synthesis and applications. When body growth is density-dependent, implementation of no-take reserves affects the body size of both protected and exploitable individuals. Although reserves can have several benefits besides increasing yields, our study shows that, if density-dependent somatic effects are important, a general increase in yield biomass cannot be expected. In populations with density-dependent body growth, reserves are more likely to decrease yield biomass unless the population is severely overexploited. Analyses of the efficiency of marine reserves as a means of enhancing the yield of fisheries need to account for ecological processes, and density-dependent body growth is likely to be key.

Fishery management; larval drift; marine protected areas; population dynamics; size at age; size-structured model; somatic growth

Gardmark, A., N. Jonzen and M. Mangel. 2006. Density-dependent body growth reduces the potential of marine reserves to enhance yields. Journal of Applied Ecology. 43:61-69.

  1. Some models of marine no-take reserves predict that reserves can enhance fishery yield. However, empirical evidence of this remains inconclusive. One reason for this may be the disregard for density-dependent body growth in most models. Density-dependent body growth links the number and size of individuals, and thus could influence the biomass of fishery yield.
  2. We developed an age- and size-structured model of an exploited population and analysed the effect of implementing a no-take reserve of varying size.
  3. Protecting part of a population from exploitation in a no-take reserve results in a rapid build-up of biomass inside the reserve because of increased survival. However, when body growth is density-dependent it also results in reduced length at a given age within the no-take reserve because of crowding effects. This prediction is backed up by empirical observations.
  4. If there is export of individuals (here larvae) from the no-take reserve, length at a given age will also decrease in the fished part of the population outside the reserve. An increase in the number of exploitable individuals thus results in decreased individual body mass. The positive effect of larval drift on fished population size and catch numbers will therefore rarely translate into an increase in equilibrium yield biomass.
  5. Synthesis and applications. When body growth is density-dependent, implementation of no-take reserves affects the body size of both protected and exploitable individuals. Although reserves can have several benefits besides increasing yields, our study shows that, if density-dependent somatic effects are important, a general increase in yield biomass cannot be expected. In populations with density-dependent body growth, reserves are more likely to decrease yield biomass unless the population is severely overexploited. Analyses of the efficiency of marine reserves as a means of enhancing the yield of fisheries need to account for ecological processes, and density-dependent body growth is likely to be key.

fishery management; larval drift; marine protected areas; population dynamics; size at age; size-structured model; somatic growth

Gaylord, B., S. D. Gaines, D. A. Siegel and M. H. Carr. 2005. Marine reserves exploit population structure and life history in potentially improving fisheries yields. Ecological Applications. 15:2180-2191.

The collapse of many of the world's fisheries has induced a reevaluation of existing fisheries management strategies. This has fueled interest in the establishment of networks of no-take marine reserves as an additional form of protection. Proponents of marine reserves have suggested that reserves can provide a number of advantages over other, more traditional, methods. However, concerns have also persisted that marine reserves will reduce overall catch. In a theoretical context, this concern has been only partially addressed by previous work suggesting that reserves can produce equivalent yields to those from traditional management, since this possibility is widely interpreted as a limiting case. However, an "equivalence-at-best" scenario is based on a highly simplified model construct that ignores all spatial pattern and size structure characterizing real populations. By contrast, when coupled effects of (1) spatial pattern in adult densities and larval dispersal, (2) population size structure, and (3) aspects of life history are considered in their most basic forms, model results suggest that reserve networks may have the potential to enhance fishery yields under a surprisingly large number of circumstances. Such enhancement is predicted to be greatest, and at times substantial, in species exhibiting postdispersal density dependence and that have relatively long-lived and sedentary adults, life history traits common to many harvested fishes and invertebrates. A goal of this study is to spark further theoretical attention and experimental testing on this unanticipated front.

fishery yield; harvesting; marine protected areas; spatially explicit; stage structure

Gerber, L.R., L.W. Botsford, A. Hastings, H.P. Possingham, S.D. Gaines, S.R. Palumbi, and S. Andelman. 2003. Population Models for Marine Reserve Design: A Retrospective and Prospective Synthesis. Ecological Applications 13(1) Supplement: S47-S64.

We synthesize results from existing models of marine reserves to identify key theoretical issues that appear to be well understood, as well as issues in need of further exploration. Models of marine reserves are relatively new in the scientific literature; 32 of the 34 theoretical papers we reviewed were published after 1990. These models have focused primarily on questions concerning fishery management at the expense of other objectives such as conservation, scientific understanding, recreation, education, and tourism. Roughly one-third of the models analyze effects on cohorts while the remaining models have some form of complete population dynamics. Few models explicitly include larval dispersal. In a fisheries context, the primary conclusion drawn by many of the complete population models is that reserves increase yield when populations would otherwise be overfished. A second conclusion, resulting primarily from single-cohort models, is that reserves will provide fewer benefits for species with greater adult rates of movement. Although some models are beginning to yield information on the spatial configurations of reserves required for populations with specific dispersal distances to persist, it remains an aspect of reserve design in need of further analysis. Other outstanding issues include the effects of (1) particular forms of density dependence, (2) multispecies interactions, (3) fisher behavior, and (4) effects of concentrated fishing on habitat. Model results indicate that marine reserves could play a beneficial role in the protection of marine systems against overfishing. Additional modeling and analysis will greatly improve prospects for a better understanding of the potential of marine reserves for conserving biodiversity.

Gleason, M., S. McCreary, M. Gleason, S. McCreary, M. Miller-Henson, J. Ugoretz, E. Fox, M. Merrifield, W. McClintock, P. Serpa, K. Hoffman. (2010). Science-based and stakeholder-driven marine protected area network planning: A successful case study from north central California. Ocean & Coastal Management: 1-17.

The planning process for California's Marine Life Protection Act in north central California represents a case study in the design of a regional component of a statewide network of marine protected areas (MPAs) for improved ecosystem protection. We describe enabling factors, such as a legislative mandate, political will, and adequate capacity and funding that fostered a successful planning process. We identify strategic principles that guided the design of a transparent public planning process that delivered regional MPA network proposals, which both met science guidelines and achieved a high level of support among stakeholders. We also describe key decision support elements (spatial data, planning tools, and scientific evaluation) that were essential for designing, evaluating, and refining alternative MPA network proposals and for informing decision-makers.

California Marine Life Protection Act, planning process, network proposals

Goni, R., A. Quetglas and O. Renones. 2006. Spillover of spiny lobsters Palinurus elephas from a marine reserve to an adjoining fishery. Marine Ecology Progress Series. 308:207-210.

We investigate the effects of the Columbretes Islands Marine Reserve (CIMR, Western Mediterranean) on the adjacent Palinurus elephas (Fabricius, 1787) fishery. After 9 to 12 yr of no-take protection there was a gradient of lobster density from the interior of the reserve up to a distance of about 4 km from its boundary. Catch and effort data were collected onboard commercial fishing boats in the fishery adjacent to the CIMR, and combined with catch per unit effort (CPUE) data from monitoring surveys conducted annually inside the reserve. Generalized additive (GAM) and linear (GLM) models were employed to examine the relationships of CPUE and catch per unit area (CPUA) as a function of distance to the reserve boundary. CPUE showed a significant non-linear decline with distance from the centre of the reserve, with a depression at the boundary followed by a plateau. This depression was caused by local depletion associated with concentration of fishing effort at the reserve boundary, while the plateau suggests that lobster export from the reserve is sufficient to maintain stable catch rates up to 1500 m from the boundary. Commercial catch and effort data were combined to estimate CPUA, which declined linearly with distance from the reserve. Analysis of recaptures of lobsters tagged and released inside the reserve indicates that the density gradient is caused by lobsters emigrating from the reserve.

Marine reserve; Spiny lobster; Spillover; Tag-recapture; Artisanal fisheries; Western Mediterranean

Grafton, R. Q., T. Kompas and V. Schneider. 2005. The bioeconomics of marine reserves: A selected review with policy implications. Journal of Bioeconomics. 7:161-178.

The paper 'bridges the divide' between the biological and economic literature on marine reserves. It provides a selected review of the traditional use of reserves, the early reserve literature, the potential benefits of reserves, spillovers from reserves to harvested areas and bioeconomic models of marine reserves. The bioeconomics literature is examined from the perspectives of deterministic models, spatial economic models and models that include uncertainty and stochasticity. Insights from the review are used to provide management implications in terms of reserve design, stakeholder cooperation and process, reserve-fishery transfers, traditional management controls, and ecosystem approaches to managing fisheries.

Reserve spillovers; deterministic; stochasticity; spatial models; fisheries management

Grafton, R. Q., T. Kompas and D. Lindenmayer. 2005. Marine reserves with ecological uncertainty. Bulletin of Mathmatical Biology. 67:957-971.

To help manage the fluctuations inherent in fish populations scientists have argued for both an ecosystem approach to management and the greater use of marine reserves. Support for reserves includes empirical evidence that they can raise the spawning biomass and mean size of exploited populations, increase the abundance of species and, relative to reference sites, raise population density, biomass, fish size and diversity. By contrast, fishers often oppose the establishment and expansion of marine reserves and claim that reserves provide few, if any, economic payoffs. Using a stochastic optimal control model with two forms of ecological uncertainty we demonstrate that reserves create a resilience effect that allows for the population to recover faster, and can also raise the harvest immediately following a negative shock. The tradeoff of a larger reserve is a reduced harvest in the absence of a negative shock such that a reserve will never encompass the entire population if the goal is to maximize the economic returns from harvesting, and fishing is profitable. Under a wide range of parameter values with ecological uncertainty, and in the 'worst case' scenario for a reserve, we show that a marine reserve can increase the economic payoff to fishers even when the harvested population is not initially overexploited, harvesting is economically optimal and the population is persistent. Moreover, we show that the benefits of a reserve cannot be achieved by existing effort or output controls. Our results demonstrate that, in many cases, there is no tradeoff between the economic payoff of fishers and ecological benefits when a reserve is established at equal to, or less than, its optimum size.

Grantham, B.A., G.L. Eckert, and A.L. Shanks. 2003. Dispersal Potential of Marine Invertebrates in Diverse Habitats. Ecological Applications 13(1) Supplement: S108-S116.

Life-history parameters were used to estimate the dispersal potential of 1021 marine macroinvertebrates recorded in species lists from 91 sites comprising rocky intertidal, subtidal, kelp forest, sandy beach, and soft-bottom habitats in Washington, Oregon, and California. Mean species richness was significantly greater in the California rocky subtidal habitat. Data on development mode, planktonic larval duration, rafting potential, and adult mobility were compiled, and summaries of the dispersal potentials of taxa within each habitat type were generated and compared. In summary, development mode was known or estimated for 76% of species; larval planktonic duration for 49%; adult mobility for 76%; and rafting potential for 46%. In comparisons of species' life-history traits among habitats, sand-dominated habitats were distinct from rocky habitats. In rocky habitats;42% of species had planktonic feeding larvae, 43% had planktonic nonfeeding larvae, and 15% had nonplanktonic larvae. Sandy intertidal habitats had higher proportions of taxa with nondispersing, nonplanktonic larvae and lower proportions of planktonic feeding and nonfeeding larvae than all other sites. Soft-bottom subtidal communities had the highest proportion of taxa with planktonic feeding development and larvae with planktonic lifespans .30 d. Species in soft-bottom subtidal sites, therefore, have the greatest potential for extensive larval dispersal, whereas species in soft-bottom intertidal sites have the least potential for larval dispersal. In these sites with limited larval dispersal potential, there is greater potential for adult dispersal through adult movement and rafting. These differences in the dispersal potential of larvae and adults suggest that the effect of environmental changes and the effectiveness of reserves may differ between habitats. Conservation methods, including the use of marine reserves, must therefore be tailored to the habitat of interest if effective protection of community resources is to be achieved.

Grober-Dunsmore, R., L. Wooninck, J. Field, C. Ainsworth, J. P. Beets, S. Berkeley, J. A. Bohnsack, R. Boulon, R. D. Brodeur, J. Brodziak, L. Crowder, D. F. Gleason, M. A. Hixon, L. Kaufman, W. L. Lindberg, M. L. Miller, L. Morgan and C. Wahle. 2008.Vertical Zoning in Marine Protected Areas: Ecological Considerations For Balancing Pelagic Fishing With Conservation of Benthic Communities. Fisheries. 33:598-610.

Marine protected areas (MPAs), ideally, manage human uses that threaten ecosystems, or components of ecosystems. During several recent MPA designation processes, concerns have arisen over the scientific justification for no-take MPAs, particularly those that restrict recreational fishing for pelagic species. An important question is: under what conditions might recreational pelagic fishing be compatible with the conservation goals of an MPA that is primarily focused on benthic communities? In 2005, an expert workshop of fisheries biologists, marine ecologists, MPA managers, and recreational fishermen was convened by NOAA's National MPA Center to evaluate the limited empirical data on benthic-pelagic coupling and to help provide practical advice on this topic. The participants (i) proposed a preliminary conceptual framework for addressing vertical zoning, (ii) developed preliminary guidelines to consider when evaluating whether to allow or restrict pelagic fishing in an MPA, and (iii) identified future research priorities for understanding benthic-pelagic coupling. A suite of ecological conditions where recreational pelagic fishing may not be compatible with benthic conservation were identified: (1) high relief habitats, (2) depths shallower than 50-100 m (depending upon the specific location), (3) major topographic and oceanographic features, and (4) spawning areas. Similarly, pelagic fishing is not likely to affect benthic communities adversely in many circumstances. Until further scientific study can shed more light on the issue of how benthicpelagic linkages affect specific conservation targets, the proposed framework in this manuscript provides practical, easily-applied guidance for using vertical zoning to manage fishing in multiple use MPAs that focus on benthic conservation.

Guenette, S. and T.J. Pitcher. 1999. An age-structured model showing the benefits of marine reserves in controlling overexploitation. Fisheries Research 39: 295-303

Previous modeling of areas closed to fishing (marine reserves) has generally employed non-dynamic models and has not included biological factors such as stock-recruitment and weight-fecundity relations. These models predicted that a marine reserve would result in a decrease in fishery yield, an increase in spawning biomass and that movements of fish across the reserve boundaries could reduce its benefits. We utilised an age-structured model based on an Atlantic cod population that included more realistic reproductive factors. We compared a Reserve regime that contained a reserve with a No-reserve regime in which the usual fishery management tools were used. As exploitation rate increased, the relative recruitment and spawners biomass decreased in the No-reserve regime. Larger reserves resulted in more robust recruitment and biomass of spawners. At low exploitation rates, marine reserves resulted in smaller yields. However, when the exploitation rate was larger than the rate which gives the maximum sustainable yield, the biomass of female spawners was maintained at a higher level in the Reserve regime and hence the yield did not collapse. Faster rate of movement of fish decreased these advantages, but the higher spawners biomass and level of recruitment still provided advantages for the Reserve regime. Moreover, even for highly mobile fish, our model suggests that a fish stock protected with a marine reserve would be more resilient to exploitation than when managed without. However, a model realistic spatially and temporally would be necessary to assess the usefulness of marine reserves to prevent overexploitation of migrating fish

Guidetti, P. and E. Sala. 2007. Community-wide effects of marine reserves in the Mediterranean Sea. Marine Ecology Progress Series. 335:43-56.

We investigated the community-wide effects of no-take marine reserves at the regional scale in the Mediterranean Sea. Reserves had general positive effects of protection on fish targeted by fishing, and variable effects on non-target species. Differences in the structure of fish assemblages (in terms of abundance of species and trophic groups) were greater between geographic locations than when compared among all protected and adjacent fished areas at the regional scale. These results suggest that the assemblage-wide response to protection at the species level may be spatially idiosyncratic, as a function of local factors. However, the functional (trophic group) response of the fish assemblages to protection appears to be more general. Response of fish assemblages to protection was significantly related to reserve age (i.e. duration of protection) only when evaluated at functional level, whereas reserve size did not appear to influence fish assemblages at either species or functional level. Reserves can enhance trophic cascades and ecological shifts once the density of fish predators of sea urchins reaches a density threshold of about 15 adult sea breams (Diplodus sargus and D. vulgaris, the most important sea urchin predators) per 100 m2. These non-linearities in the community-wide effect of reserves suggest that caution is needed in simplistically treating reserves and unprotected areas as 2 experimental treatments in ecological studies.

Marine reserves; Rocky reef fish; Reserve age and size; Sea urchins; Trophic cascades; Mediterranean Sea

Guidetti, P. 2002. The importance of experimental design in detecting the effects of protection measures on fish in Mediterranean MPAs. Aquatic Conservation: Marine and Freshwater Ecosystems. 12: 619-634

  1. Marine protected areas (MPAs) are currently proliferating in the Mediterranean Sea. The assessment of their role in the protection and recovery of overexploited fish populations, however, is not yet completely supported by an adequate body of scientific evidence. This is in part because the number of studies that unambiguously assess changes induced by protection is limited.
  2. Sampling to detect and measure the expected effects of protection on commercial fish (e.g. increase in mean abundance and size) is made difficult by intrinsic natural spatial and temporal variability. Ideally, temporal replication before and after the establishment of MPAs is necessary for estimating the average conditions in time. Spatial replication of control locations, on the other hand, is essential to prevent confusion in interpreting a difference between protected and unprotected locations. Until now, the basic requirements for appropriate experimental designs in MPAs were seldom satisfied, especially in the Mediterranean region.
  3. In the present paper, an ideal experimental design aimed at overcoming many of the confounding influences that could result in misinterpretations of the results is considered, with a discussion of implications of applying less and less appropriate designs because of pragmatic constraints. Experimental design should thus be adapted to each individual MPA under study on the basis of the specific constraints that researchers face (e.g. 'before' (i.e. pre-designation) data are lacking; there is a single or more than one protected locations).
  4. The issues related to MPAs, chiefly in the Mediterranean region, need to be considered to enable the identification of unambiguous hypotheses prior to sampling, based on clear logical structures. The importance of appropriate sampling and the subsequent interpretation of data would progressively reduce the degree of uncertainty of environmental analyses about the effects of MPAs on fish, with important implications for their management and further proliferation.

Hall, D. C., J. V. Hall and S. N. Murray. 2002. Contingent valuation of marine protected areas: southern California rocky intertidal ecosystems. Natural Resource Modeling. 15:335-368.

Designation as Marine Protected Areas (MPAs) can protect coastal ecosystems, but apparently has not effectively protected the rocky intertidal zone in urban Southern California. Here, illegal collecting and habitat disturbance harm coastal marine life. We surveyed day visitors to sandy beaches or adjacent rocky habitats in Orange County. Using the close-ended, double-bounded contingent valuation method, we estimate the benefit of more effective enforcement and management of MPAs designed to avoid coastal ecosystem decay. We solve the problem of sample selection bias, introduced by the likelihood that the sample disproportionately includes respondents who visit more frequently and who may have a higher willingness to pay (WTP). We estimate the WTP for enacting policies to reduce illegal collecting and onsite habitat disturbance to average $6 per family-visit. Our estimate is consistent with other studies that estimate consumer surplus at $15 per person-trip for nearby, lower quality beaches, and extrapolates from other studies to $3.6 $4.8 million per mile of coastline.

Marine Protected Areas; rocky intertidal zone; coastal ecosystems; biodiversity; marine life; contingent valuation; sample selection bias; willingness-to-pay

Halpern, B. S., S. E. Lester, and K. L. McLeod. (2010). Placing marine protected areas onto the ecosystem based management seascape. PNAS Early Edition: 1-6.

The rapid increase in the science and implementation of marine protected areas (MPAs) around the world in the past 15 years is now being followed by similar increases in the science and application of marine ecosystem-based management (EBM). Despite important overlaps and some common goals, these two approaches have remained either separated in the literature and in conservation and management efforts or treated as if they are one and the same. In the cases when connections are acknowledged, there is often little assessment of if or how well MPAs can achieve specific EBM goals. Here we start by critically evaluating commonalities and differences between MPAs and EBM. Next, we use global analyses to show where and how much no take marine reserves can be expected to contribute to EBM goals, specifically by reducing the cumulative impacts of stressors on ocean ecosystems. These analyses revealed large stretches of coastal oceans where reserves can play a major role in reducing cumulative impacts and thus improving overall ocean condition, at the same time highlighting the limitations of marine reserves as a single tool to achieve comprehensive EBM. Ultimately, better synergies between these two burgeoning approaches provide opportunities to greatly benefit ocean health.

cumulative impacts, fisheries, global, no-take reserves, ocean health

Halpern, B. S., K. L. McLeod, A. A. Rosenberg and L. B. Crowder. 2008. Managing for cumulative impacts in ecosystem-based management through ocean zoning. Ocean and Coastal Management. 51:203-211.

Multiple activities affect the marine environment in concert, yet current management primarily considers activities in isolation. A shift towards a more comprehensive management of these activities, as with recent emphasis on ecosystem-based approaches to management, requires a means for evaluating their interactive and cumulative impacts. Here we develop a framework for this evaluation, focusing on five core concepts: (1) activities have interactive and cumulative impacts, (2) management decisions require consideration of, and tradeoffs among, all ecosystem services, (3) not all stressors are equal or have impacts that increase linearly, (4) management must account for the different scales of activities and impacts, and (5) some externalities cannot be controlled locally but must be accounted for in marine spatial planning. Comprehensive ocean zoning provides a powerful tool with which these key concepts are collectively addressed.

Halpern, B. S., S. Walbridge, K. A. Selkoe, C. V. Kappel, F. Micheli, C. D'Argrosa, J. F. Bruno, K. S. Casey, C. Ebert, H. E. Fox, R. Fujita, D. Heinemann, H. S. Lenihan, E. M. P. Madin, M. T Perry, E. R Selig, M. Spalding, R. Steneck, and R. Watson. (2008). A Global Map of Human Impact on Marine Ecosystems. Science 319: 948-952.

The management and conservation of the world's oceans require synthesis of spatial data on the distribution and intensity of human activities and the overlap of their impacts on marine ecosystems. We developed an ecosystem-specific, multiscale spatial model to synthesize 17 global data sets of anthropogenic drivers of ecological change for 20 marine ecosystems. Our analysis indicates that no area is unaffected by human influence and that a large fraction (41%) is strongly affected by multiple drivers. However, large areas of relatively little human impact remain, particularly near the poles. The analytical process and resulting maps provide flexible tools for regional and global efforts to allocate conservation resources; to implement ecosystem-based management; and to inform marine spatial planning, education, and basic research.

Management, human impact, ecological change

Halpern, B. S., H. M. Regan, H. P. Possingham and M. A. McCarthy. 2006. Accounting for uncertainty in marine reserve design. Ecology Letters. 9:2-11.

Ecosystems and the species and communities within them are highly complex systems that defy predictions with any degree of certainty. Managing and conserving these systems in the face of uncertainty remains a daunting challenge, particularly with respect to developing networks of marine reserves. Here we review several modelling frameworks that explicitly acknowledge and incorporate uncertainty, and then use these methods to evaluate reserve spacing rules given increasing levels of uncertainty about larval dispersal distances. Our approach finds similar spacing rules as have been proposed elsewhere - roughly 20-200 km - but highlights several advantages provided by uncertainty modelling over more traditional approaches to developing these estimates. In particular, we argue that uncertainty modelling can allow for (1) an evaluation of the risk associated with any decision based on the assumed uncertainty; (2) a method for quantifying the costs and benefits of reducing uncertainty; and (3) a useful tool for communicating to stakeholders the challenges in managing highly uncertain systems. We also argue that incorporating rather than avoiding uncertainty will increase the chances of successfully achieving conservation and management goals.

Dispersal; marine protected areas; marine reserves; metapopulation model; reserve networks; spacing; uncertainty

Halpern, B. S. and R. R. Warner. 2003. Matching marine reserve design to reserve objectives. Proceedings of the Royal Society B: Biological Sciences. 270:1871-1878.

Recent interest in using marine reserves for marine resource management and conservation has largely been driven by the hope that reserves might counteract declines in fish populations and protect the biodiversity of the seas. However, the creation of reserves has led to dissension from some interested groups, such as fishermen, who fear that reserves will do more harm than good. These perceived differences in the effect of marine reserves on various stakeholder interests has led to a contentious debate over their merit. We argue here that recent findings in marine ecology suggest that this debate is largely unnecessary, and that a single general design of a network of reserves of moderate size and variable spacing can meet the needs and goals of most stakeholders interested in marine resources. Given the high fecundity of most marine organisms and recent evidence for limited distance of larval dispersal, it is likely that reserves can both maintain their own biodiversity and service nearby non-reserve areas. In particular, spillover of larger organisms and dispersal of larvae to areas outside reserves can lead to reserves sustaining or even increasing local fisheries. Ultimately, the success of any reserve network requires attention to the uncertainty and variability in dispersal patterns of marine organisms, clear statements of goals by all stakeholder groups and proper evaluation of reserve performance.

marine reserve design; fisheries; resource management; biodiversity conservation; marine protected areas

Halpern, B.S. 2003. The impact of marine reserves: do reserves work and does reserve size matter? Ecological Applications 13(1) Supplement: S117-S137.

Marine reserves are quickly gaining popularity as a management option for marine conservation, fisheries, and other human uses of the oceans. Despite the popularity of marine reserves as a management tool, few reserves appear to have been created or designed with an understanding of how reserves affect biological factors or how reserves can be designed to meet biological goals more effectively (e.g., attaining sustainable fish populations). This shortcoming occurs in part because the many studies that have examined the impacts of reserves on marine organisms remain isolated examples or anecdotes; the results of these many studies have not yet been synthesized. Here, I review the empirical work and discuss the theoretical literature to assess the impacts of marine reserves on several biological measures (density, biomass, size of organisms, and diversity), paying particular attention to the role reserve size has in determining those impacts. The results of 89 separate studies show that, on average, with the exception of invertebrate biomass and size, values for all four biological measures are significantly higher inside reserves compared to outside (or after reserve establishment vs. before) when evaluated for both the overall communities and by each functional group within these communities (carnivorous fishes, herbivorous fishes, planktivorous fishes/invertebrate eaters, and invertebrates). Surprisingly, results also show that the relative impacts of reserves, such as the proportional differences in density or biomass, are independent of reserve size, suggesting that the effects of marine reserves increase directly rather than proportionally with the size of a reserve. However, equal relative differences in biological measures between small and large reserves nearly always translate into greater absolute differences for larger reserves, and so larger reserves may be necessary to meet the goals set for marine reserves.

The quality of the data in the reviewed studies varied greatly. To improve data quality in the future, whenever possible, studies should take measurements before and after the creation of a reserve, replicate sampling, and include a suite of representative species. Despite the variable quality of the data, the results from this review suggest that nearly any marine habitat can benefit from the implementation of a reserve. Success of a marine reserve, however, will always be judged against the expectations for that reserve, and so we must keep in mind the goals of a reserve in its design, management, and evaluation.

Halpern, B. S. and R. R. Warner. 2002. Marine reserves have rapid and lasting effects. Ecology Letters. 5:361-366.

Marine reserves are becoming a popular tool for marine conservation and resource management worldwide. In the past, reserves have been created with little understanding of how they actually affect the areas they are intended to protect. A few recent reviews have evaluated how reserves in general affect the density and biomass of organisms within them, but little work has been done to assess temporal patterns of these impacts. Here we review 112 independent measurements of 80 reserves to show that the higher average values of density, biomass, average organism size, and diversity inside reserves (relative to controls) reach mean levels within a short (1–3 y) period of time and that the values are subsequently consistent across reserves of all ages (up to 40 y). Therefore, biological responses inside marine reserves appear to develop quickly and last through time. This result should facilitate their use in the management of marine resources.

Marine conservation; marine protected areas; marine reserves; temporal effects

Hamilton, S. L., J. E. Caselle, D. P. Malone, M. H. Carr. (2010). Incorporating biogeography into evaluations of the Channel Islands marine reserve network. PNAS Early Edition: 1-6.

Networks of marine reserves are increasingly a major component of many ecosystem-based management plans designed to conserve biodiversity, protect the structure and function of ecosystems, and rebuild and sustain fisheries. There is a growing need for scientific guidance in the design of network-wide monitoring programs to evaluate the efficacy of reserves at meeting their conservation and management goals. Here, we present an evaluation of the Channel Islands reserve network, which was established in 2003 off the coast of southern California. This reserve network spans a major environmental and biogeographic gradient, making it a challenge to assess network-wide responses of many species. Using fish community structure data from a long-term, large-scale monitoring program, we first identified persistent geographic patterns of community structure and the scale at which sites should be grouped for analysis. Fish communities differed most among islands with densities of individual species varying from 3- to 250-fold. Habitat structure differed among islands but not based on reserve status. Across the network, we found that, after 5 years, species targeted by fishing had higher densities (1.5×) and biomass (1.8×) inside reserves, whereas nontargeted species showed no significant differences. Examining trophic groups, piscivore and carnivore biomass was significantly greater inside reserves (1.8× and 1.3× more, respectively), whereas the biomass of planktivores and herbivores was similar inside and out. A framework for incorporating biogeographic variation into reserve network assessments is critical as we move from the evaluation of single reserves to networks of reserves.

ecosystem-based management, kelp forest ecosystem, marine protected, areas, monitoring, response ratios

Hamilton, S. L., J. Regetz, R. R. Warner. (2008). Postsettlement survival linked to larval life in a marine fish. PNAS 105(5): 1561-1566.

There is a growing realization that the scale and degree of population connectivity are crucial to the dynamics and persistence of spatially structured populations. For marine organisms with complex life cycles, experiences during larval life may influence phenotypic traits, performance, and the probability of postsettlement survival. For a Caribbean reef fish (Thalassoma bifasciatum) on an oceanic island, we used otolith (ear stone) elemental profiles of lead (Pb) to assign recent settlers to a group that developed in waters elevated in Pb concentrations throughout larval life (i.e., nearshore signature) and a group that developed in waters depleted in Pb (i.e., offshore signature), potentially dispersing from upstream sources across oceanic waters. Larval history influenced early life history traits: offshore developers initially grew slowly but compensated with fast growth upon entering nearshore waters and metamorphosed in better condition with higher energy reserves. As shown in previous studies, local production contributed heavily to settlement: at least 45% of settlers developed nearshore. However, only 23% of survivors after the first month displayed a nearshore otolith profile. Therefore, settlers with different larval histories suffered differential mortality. Importantly, selective mortality was mediated by larval history, in that the postsettlement intensity of selection was much greater for fish that developed nearshore, potentially because they had developed in a less selectively intense larval environment. Given the potential for asymmetrical postsettlement source-based survival, successful spatial management of marine populations may require knowledge of "realized connectivity" on ecological scales, which takes into account the postsettlement fitness of individuals from different sources.

larval–juvenile transition, otolith chemistry, realized connectivity, selective mortality, Thalassoma bifasciatum

Harmelin-Vivien, M., L. L. Diréach, J. Bayle-Sempere, E. Charbonnel, J. Antonio García-Chartone, D. Ody, A. Pérez-Ruzafae, O. Reñonesg, P. Sánchez-Jerez, C. Valle. (2008). Gradients of abundance and biomass across reserve boundaries in six Mediterranean marine protected areas: Evidence of fish spillover? Biological Conservation 141: 1829-1839.

Marine protected areas (MPAs) are considered as an effective tool in marine coastal management, and considered able to enhance local fisheries through adult fish spillover. Indirect evidence of fish spillover could be obtained by horizontal gradients in fish abundance. To address this question, the existence of gradients of fish abundance and biomass across marine reserve boundaries was assessed in six Mediterranean MPAs using underwater visual censuses performed at various distances from the core of the MPA, in integral reserve (IR), to buffer zone (BZ) and fished areas. A reserve effect was evidenced with higher values of fish species richness (1.1), abundance (1.3), and biomass (4.7) recorded inside MPAs compared to adjacent fished areas. Linear correlations revealed significant negative gradients in mean fish biomass in all the reserves studied after the effect of habitat had been removed, whereas negative gradients in abundance were less conspicuous. Generalized additive models suggested two main patterns of biomass gradients, with a sharp decrease at the IR–BZ boundary or at the BZ–fished area boundary. It was estimated that fish spillover beneficial to local fisheries occurred mostly at a small spatial scale (100s of metres). The existence of regular patterns of negative fish biomass gradients from within MPAs to fished areas was consistent with the hypothesis of adult fish biomass spillover processes from marine reserves and could be considered as a general pattern in this Mediterranean region.

Visual census, Fish spillover, Marine reserves, Fisheries

Hart, D. R. and M. P. Sissenwine. 2009. Marine reserve effects on fishery profits: a comment on White et al. (2008). Ecology Letters. 12:E9-E11.

A recent study (White et al. 2008) claimed that fishery profits will often be higher with management that employs no-take marine reserves than conventional fisheries management alone. However, this conclusion was based on the erroneous assumption that all landed fish have equal value regardless of size, and questionable assumptions regarding density-dependence. Examination of an age-structured version of the White et al. (2008) model demonstrates that their results are not robust to these assumptions. Models with more realistic assumptions generally do not indicate increased fishery yield or profits from marine reserves except for overfished stocks.

Marine reserves; marine protected areas; density dependence; fisheries management; bioeconomics

Hastings, A. and L. W. Botsford. (2006). Persistence of spatial populations depends on returning home. PNAS Early Edition: 1-6.

There is a need for better description and heuristic understanding of the sustainability of populations connected over space by a dispersing stage, both for management purposes and to increase our basic knowledge of the dynamics of these populations. We show that persistence of such a population of connected subpopulations depends on whether the sum of the reproductive gains through all possible closed, between-patch reproductive paths through multiple generations, relative to the shortfall in self-persistence in each path, exceeds unity plus extra terms, which only appear if there are four or more patches. These extra terms have the heuristic explanation that they avoid double counting of reproductive paths that arise with four or more patches because there can be nonoverlapping subnetworks. Thus only those patterns of reproduction and connectivity which eventually lead to descendants returning to the patch from which they originate contribute to persistence. This result provides the basis for evaluating connectivity and habitat heterogeneity to understand reserve design, the effects of human fragmentation, the collapse of marine fisheries, and other conservation issues.

connectivity, M-matrix, population dynamics, spatial dynamics, marine reserves

Hastings, A. and L.W. Botsford. 1999. Equivalence in Yield from Marine Reserves and Traditional Fisheries Management. Science. 284: 1537-1538.

Marine reserves have been proposed as a remedy for overfishing and declining marine biodiversity, but concern that reserves would inherently reduce yields has impeded their implementation. It was found that management of fisheries through reserves and management through effort control produce identical yields under a reasonable set of simplifying assumptions corresponding to a broad range of biological conditions. Indeed, for populations with sedentary adults (invertebrates and reef fishes), reserves have important advantages for sustainability, making marine reserves the preferred management approach.

Hastings, A. and L.W. Botsford. 2003. Comparing Designs of Marine Reserves for Fisheries and for Biodiversity. Ecological Applications 13(1) Supplement: S65-S70.

We compare and contrast the design of networks of marine reserves for two different, commonly stated goals: (1) maintaining high yield in fisheries and (2) conserving biodiversity, in an idealized setting using simple models. The models describe larval dispersal over a system of evenly spaced reserves of equal size, assuming sedentary adults. We initially demonstrate that, since populations in reserve systems can be sustained either by covering a minimal fraction of the coast with small reserves or by covering a smaller fraction of the coast with few large reserves, cost considerations dictate that the conservation goal would be best met by reserves as large as practically possible. In contrast, the fisheries goal of maximizing yield requires maximizing larval export outside of reserves, which we show means that reserves should be as small as practically possible. Meeting the fisheries goal is ultimately more costly because it suggests a larger area of the coastline should be in reserves, but it also improves on conservation goals by enhancing sustainability for species dispersing longer distances.

Hastings, A. and L. W. Botsford. 2003. Comparing designs of marine reserves for fisheries and for biodiversity. Ecological Applications. 13:S65-S70.

We compare and contrast the design of networks of marine reserves for two different, commonly stated goals: (1) maintaining high yield in fisheries and (2) conserving biodiversity, in an idealized setting using simple models. The models describe larval dispersal over a system of evenly spaced reserves of equal size, assuming sedentary adults. We initially demonstrate that, since populations in reserve systems can be sustained either by covering a minimal fraction of the coast with small reserves or by covering a smaller fraction of the coast with few large reserves, cost considerations dictate that the conservation goal would be best met by reserves as large as practically possible. In contrast, the fisheries goal of maximizing yield requires maximizing larval export outside of reserves, which we show means that reserves should be as small as practically possible. Meeting the fisheries goal is ultimately more costly because it suggests a larger area of the coastline should be in reserves, but it also improves on conservation goals by enhancing sustainability for species dispersing longer distances.

biodiversity; conservation; dispersal; fisheries; marine reserves; models

Helvey, M. 2004. Seeking Consensus on Designing Marine Protected Areas: Keeping the Fishing Community Engaged. Coastal Management. 32: 173-190.

A community group was formed to consider establishing marine reserves within the Channel Islands National Marine Sanctuary in southern California. Membership included representatives from resource agencies, environmental organizations, commercial and recreational fishing interests, and the general public. While the group agreed on several areas for fishing closures, members could not reach consensus on a specific network design. Several factors interfered with the group's effort in attaining agreement resulting in the endeavor subsequently being replaced by a "topdown" approach that lacks the support of the fishing community. Lessons learned from the project emphasize the need by marine protected area participants to recognize irreconcilable impasses early in the process and to seek solutions to maneuver around them. The importance of keeping the fishing community fully engaged is discussed.

Hilborn, R. K. Stokesb, J. Maguirec, T. Smith, L.W. Botsford, M. Mangel, J. Orensanz, A. Parma, J. Rice, J. Bell, K.L. Cochrane, S. Garcia, S.J. Hall, G.P. Kirkwood, K. Sainsbury, G. Stefansson, C. Walters. 2004. When can marine reserves improve fisheries management? Ocean and Coastal Management. In Press.

Marine reserves are a promising tool for fisheries management and conservation of biodiversity, but they are not a panacea for fisheries management problems. For fisheries that target highly mobile single species with little or no by-catch or habitat impact, marine reserves provide few benefits compared to conventional fishery management tools. For fisheries that are multi-species or on more sedentary stocks, or for which broader ecological impacts of fishing are an issue, marine reserves have some potential advantages. Their successful use requires a case-by-case understanding of the spatial structure of impacted fisheries, ecosystems and human communities. Marine reserves, together with other fishery management tools, can help achieve broad fishery and biodiversity objectives, but their use will require careful planning and evaluation. Mistakes will be made, and without planning, monitoring and evaluation, we will not learn what worked, what did not, and why. If marine reserves are implemented without case by case evaluation and appropriate monitoring programs, there is a risk of unfulfilled expectations, the creation of disincentives, and a loss of credibility of what potentially is a valuable management tool.

Hofmann, G. E. and S. D. Gaines. (2008). New Tools to Meet New Challenges: Emerging Technologies for Managing Marine Ecosystems for Resilience. BioScience 58(1): 43-52.

The goal of this article is to highlight evolving tools, recent advances, and emerging techniques that are being used to understand natural variability in marine ecosystems. These technical approaches range from the tagging of large pelagic organisms to the use of genomics to provide insight into the abundance and health of marine organisms. Although these techniques vary dramatically in scale, they share the potential to remove critical impediments to the effective management of marine systems.

marine ecosystem-based management, marine ecosystems, resilience

Holland, D.S. 2002. Integrating marine protected areas into models for fishery assessment and management. Natural Resource Modeling. 15: 369-386.

Marine protected areas (MPAs) have been proposed as an insurance policy against fishery management failures and as an integral part of an optimal management system for some fisheries. However, an incorrectly designed MPA can increase the risk of depletion of some species, and can reduce the value of the system of fisheries it impacts. MPAs may alter structural processes that relate fishery outcomes to management variables and thereby compromise the models that are used to guide decisions. New models and data gathering programs are needed to use MPAs effectively. This paper discusses the motivations and methods for incorporating explicitly spatial dynamics of both fish and fishermen into fishery models so that they can be used to assess spatial policies such as MPAs. Some important characteristics and capabilities which these models should have are outlined, and a topical review of some relevant modeling methodologies is provided.

Marine protected areas; spatial modeling; fisheries management

Hsieh, C.-h., C. S. Reiss, R. P. Hewitt, G. Sugihara. (2008). Spatial analysis shows that fishing enhances the climatic sensitivity of marine fishes. Canadian Journal of Fisheries Aquatic Science 65: 947-961.

We compare the changes in geographic distribution of exploited fish species versus unexploited ones living in the same environment. For this comparative study, we use the 50-year larval fish time series from the California Cooperative Oceanic Fisheries Investigations, which allows us to view fishing as a treatment effect in a long-term ecological experiment. Our results indicate that exploited species show a clearer distributional shift in response to environmental change than unexploited species, even after accounting for life history and ecological traits and phylogeny. The enhanced response (improved signal–noise ratio) to environmental change in exploited species may be a consequence of reduced spatial heterogeneity caused by fishery-induced age (size) truncation and the constriction of geographic distribution that accompanies fishing pressure. We suggest that reduced spatial heterogeneity can cause exploited populations to be more vulnerable to climate variability, an effect that could have considerable importance in the management of fish stocks. This is the first study to compare the geographic distributions of a large suite of exploited and unexploited fish species from the northeastern Pacific in response to climate variability.

Larval fish, California Cooperative Oceanic Fisheries, signal-noise ratio

Jackson, J.B.C., M.X. Kirby, W.H. Berger, K.A. Bjorndal, L.W. Botsford, B.J. Bourque, R.H. Bradbury, R. Cooke, J. Erlandson, J.A. Estes, T.P. Hughes, S. Kidwell, C.B. Lange, H.S. Lenihan, J.M. Pandolfi, C.H. Peterson, R.S. Steneck, M.J. Tegner, R.R. Warner. 2001. Historical Overfishing and the Recent Collapse of Coastal Ecosystems. Science 293(27): 629-638.

Ecological extinction caused by overfishing precedes all other pervasive human disturbance to coastal ecosystems, including pollution, degradation of water quality, and anthropogenic climate change. Historical abundances of large consumer species were fantastically large in comparison with recent observations. Paleoecological, archaeological, and historical data show that time lags of decades to centuries occurred between the onset of overfishing and consequent changes in ecological communities, because unfished species of similar trophic level assumed the ecological roles of overfished species until they too were overfished or died of epidemic diseases related to overcrowding. Retrospective data not only help to clarify underlying causes and rates of ecological change, but they also demonstrate achievable goals for restoration and management of coastal ecosystems that could not even be contemplated based on the limited perspective of recent observations alone.

Jessopp, M. J. and R. J. McAllen. 2007. Water retention and limited larval dispersal: implications for short and long distance dispersers in marine reserves. Marine Ecology Progress Series. 333:27-36.

Although the establishment of reserves is central to marine conservation, previous criteria for the selection of appropriate areas has often been based on historical, aesthetic or logistic factors, resulting in a network of marine reserves that may not effectively meet conservation objectives. Since the dispersal of larvae plays an integral role in determining whether reserves can sustain themselves, whether they can exchange larvae with other protected sites, or whether they can supplement surrounding exploited areas, effective reserve design requires consideration of the processes that may affect larval dispersal. Plankton tows were conducted monthly for 12 mo in a semienclosed marine reserve with long water retention time, in bays with low water retention, and along open coastline, to establish whether larval retention plays an important role in limiting dispersal and creating discrete communities. Significant spatial and temporal differences in larval assemblages were found, with the semi-enclosed reserve, bay, and coast areas showing consistent differences throughout the year. An ANOVA carried out on 11 species identified as differentiating between these areas supported the hypothesis that limited larval exchange was occurring between reserve and nonreserve areas, despite potentially large dispersal distances. Designating bays as reserve areas may provide a means of protecting various species with both long and short dispersal distances, but this must be balanced against the reduced likelihood of closed populations to recover from local catastrophes and the possibility of limited genetic differentiation and inbreeding.

Marine Protected Areas; MPA; Larval dispersal; Water retention; Lough Hyne; Population sustainability

Johansson, M. L., M. A. Banks, K. D. Glunt, H. M Hassel-Finnegan, and V. P. Buonaccorsi. (2008). Influence of habitat discontinuity, geographical distance, and oceanography on fine-scale population genetic structure of copper rockfish (Sebastes caurinus). Molecular Ecology 17: 3051-3061.

The copper rockfish is a benthic, nonmigratory, temperate rocky reef marine species with pelagic larvae and juveniles. A previous range-wide study of the population-genetic structure of copper rockfish revealed a pattern consistent with isolation-by-distance. This could arise from an intrinsically limited dispersal capability in the species or from regularly–spaced extrinsic barriers that restrict gene flow (offshore jets that advect larvae offshore and/or habitat patchiness). Tissue samples were collected along the West Coast of the contiguous USA between Neah Bay, WA and San Diego, CA, with dense sampling along Oregon. At the whole-coast scale (~2200 km), significant population subdivision (FST = 0.0042), and a significant correlation between genetic and geographical distance were observed based on 11 microsatellite DNA loci. Population divergence was also significant among Oregon collections (~450 km, FST = 0.001). Hierarchical AMOVA identified a weak but significant 130-km habitat break as a possible barrier to gene flow within Oregon, across which we estimated that dispersal (Nem) is half that of the coast-wide average. However, individual-based Bayesian analyses failed to identify more than a single population along the Oregon coast. In addition, no correlation between pairwise population genetic and geographical distances was detected at this scale. The offshore jet at Cape Blanco was not a significant barrier to gene flow in this species. These findings are consistent with low larval dispersal distances calculated in previous studies on this species, support a mesoscale dispersal model, and highlight the importance of continuity of habitat and adult population size in maintaining gene flow.

ichthyoplankton ecology, larval dispersal, marine protected areas, marine reserves, population genetics

Jones, P. J. 2002. Marine protected area strategies: issues, divergences and the search for middle ground. Reviews in Fish Biology and Fisheries. 11:197-216.

 There has been a dramatic increase in recent years in the number of papers, reports, etc., which have been published concerning Marine Protected Areas (MPAs). This overview of the objectives, selection, design and management of MPAs aims to provide a basis for discussion regarding possible ways forward by identifying emerging issues, convergences and divergences.Whilst the attributes of the marine environment may limit the effectiveness of sitespecific initiatives such as MPAs, it is argued that it would be defeatist in the extreme to abandon MPAs in the face of these limitations. Ten key objectives for MPAs are discussed, including that of harvest refugia, and it is argued that whilst these objectives may be justifiable from a preservationist perspective, they may be objected to from a resource exploitation perspective. MPAs generate both internal (between uses) and basic (between use and conservation) conflicts, and it is argued that these conflicts may be exacerbated when scientific arguments for MPAs are motivated by preservationist concerns. It is reported that a minority of MPAs are achieving their management objectives, and that for the majority insufficient information was available for such effectiveness evaluations. Structure and process-oriented perspectives on marine conservation are discussed. It is argued that there are two divergent stances concerning optimal MPA management approaches: top-down, characterized as being government-led and science-based, with a greater emphasis on set-aside; and bottom-up, characterized as being community-based and science-guided, with a greater emphasis on multiple-use. Given the divergent values of different stakeholders, the high degree of scientific uncertainty, and the high marine resource management decision stakes, it is concluded that a key challenge is to adopt a “middle-ground” approach which combines top-down and bottom-up approaches, and which is consistent with the post-normal scientific approach.

Kaplan, D. M. 2006. Alongshore advection and marine reserves: consequences for modeling and management. Marine Ecology Progress Series. 309:11-24.

The appropriate configuration of marine reserves for maximizing harvests or ensuring species persistence when there is uncertainty or variability in larval dispersal patterns is not completely understood. This is particularly true in environments with large alongshore advection rates, as the success of a system of marine reserves depends on connectivity through larval and/or adult dispersal between adjacent marine reserves. In this paper, the consequences of alongshore advection in the presence of marine reserves for a fish species with sedentary adults and widely dispersing larvae are examined. First, a uniform configuration of reserves with constant alongshore advection rate is considered. The highest overall catch and recruitment rates occur when the spacing between reserves is precisely tuned to the advection distance. When the alongshore advection distance is allowed to vary in time, catch and recruitment are considerably less sensitive to alongshore advection. At small diffusion distances, catch values differ from what would be predicted from the time averaged larval dispersal pattern due to density-dependent post-settlement effects. It is important to include short time scale settlement variability in marine reserve models under these conditions. When the spacing between reserves is allowed to vary, the tuning of the system to particular advection distances is less precise. Configurations of marine reserves with a variety of spacings between reserves exhibited more uniform catch levels as a function of advection distance. This suggests that variability in the spacing between reserves is desirable for protecting a diverse group of species with different dispersal patterns.

 Marine protected areas; Fisheries management; Population dynamics; Variable reserve-spacing; Advection variability

Kaplan, D. M. and L. W. Botsford. 2005. Effects of variability in spacing of coastal marine reserves on fisheries yield and sustainability. Canadian Journal of Fisheries and Aquatic Sciences. 62:905-912.

The size and configuration of marine reserves best suited to reaching fisheries and conservation goals are poorly understood. It has been suggested that variable spacing between reserves is essential to the success of a system of marine reserves. We used numerical models to examine the effect of variable spacing on the efficacy of marine reserves for managing a fish species with sedentary adults and planktonic larvae. Variability in reserve spacing affected catch and recruitment relative to values for a uniform configuration of reserves only for populations near collapse even in the presence of a system of reserves. For species with low fishing rates or large marine reserves, variability in spacing had only a minor effect. At high fishing rates and small reserve sizes, variable reserve placement had a positive local effect on catch and recruitment when several reserves fell close to each other. These configurations led to uneven spatial distributions with greater catch and recruitment in areas with a higher concentration of reserves. Variable reserve spacing can offer additional protection to overfished populations along certain sections of the coastline, but concern for spatial homogeneity will argue for a uniform distribution of reserves covering an adequate proportion of the entire coastline.

Kaplan, D. M. 2009. Fish life histories and marine protected areas: an odd couple? Marine Ecology Progress Series. 377:213-225.

Though marine protected areas (MPAs) have recently become a central element of many marine resource management plans, the potentially negative effects of MPAs for fisheries harvests remain the major impediment to their use. Understanding population responses to implementation of MPAs, and their consequences for harvests, is essential to assessing the value of MPAs as a management tool. Here I use a simple model to link what we know best about marine species, namely how fast they grow and how much they reproduce, with what we want to know, namely what will be the effects of spatial management efforts. Specifically, I show that whether maximum sustainable yield (MSY) or yield at fixed total recruitment increases with MPAs can be determined by an intuitive equation comparing the change in average individual biomass (i.e. harvestable material) with the change in individual lifetime reproduction due to increasing reserve area. Application of this model to different population structures demonstrates that initial MPA results indicating MSY would be unchanged with reserves for species with simple life-histories do not hold up for species for which biomass, reproduction or mortality vary with age. This explains many negative MPA results from age-structured models of optimally exploited species. On the other hand, the model predicts that species harvested later in life, and which begin reproduction after first harvest, may benefit from MPAs. Nevertheless, for these increases to occur, the age at first reproduction must in general be a considerable time after the age at first harvest.

Marine protected area; MPA; Life history traits; Growth rates; Fisheries; management; Density dependence; Harvesting strategy; Maximum sustainable yield; MSY

Kaplan, D.M., L. W. Botsford, M. R. O'Farrell, S. D. Gaines and S. Jorgensen. 2009. Model-based assessment of persistence in proposed marine protected area designs. Ecological Applications. 19:433-448.

Assessment of marine protected areas (MPAs) requires the ability to quantify the effects of proposed MPA size and placement, habitat distribution, larval dispersal, and fishing on the persistence of protected populations. Here we describe a model-based approach to assessment of the contribution of a network of marine protected areas to the persistence of populations with a sedentary adult phase and a dispersing larval phase. The model integrates the effects of a patchy spatial distribution of habitat, the spatial scale of larval dispersal, and the level of fishing outside of reserves into a calculation of the spatial distribution of equilibrium settlement. We use the amount of coastline predicted to have equilibrium settlement rates that saturate post-settlement habitat as a response variable for the assessment and comparison of MPA network designs. We apply this model to a set of recently proposed MPA networks for the central coast of California, USA. Results show that the area of habitat set aside is a good predictor of the area over which population levels will be high for short-distance dispersers. However, persistence of longer distance dispersers depends critically on the spatial distribution of habitat and reserves, ranging from not persistent anywhere to persistent over a greater area than that set aside in reserves. These results depend on the mechanisms of persistence, with self-replacement supporting short-distance dispersers and network effects supporting long-distance dispersers. Persistence also depends critically on fishery status outside the MPAs, as well as how fishing effort is redistributed after MPA implementation. This assessment method provides important benchmarks, as well as a transparent modeling approach, for improving initial MPA configurations that may result from less-comprehensive rule- or habitat-based methods of designing MPAs.

California coastline; USA; fisheries management; fishing; habitat distributions; larval dispersal; marine conservation; marine protected areas; metapopulations; modeling; persistence; rockfish; Sebastes spp

Karpov, K.A., M.J. Tegner, L. Rogers-Bennett, P.E. Kalvass, I.K. Taniguchi. 2001. Interactions Among Red Abalones and Sea Urchins in Fished and Reserve Sites of Northern California: Implications of Competition to Management. Journal of Shellfish Research. 20(2):743-53.

Red abalones (Haliotis rufescens), red sea urchins (Strongylocentrotus franciscanus), and purple sea urchins (S. purpuratus) share similar food and habitat requirements in northern California. Red abalones and red sea urchins also support important fisheries. Here we explore spatial interactions and apparent competitive effects among these species at an area where fishing has large impacts on both taxa, and at unfished reserve sites in which invertebrate density and food availability differ. There was an inverse correlation between adult red abalone and red sea urchin abundance at the scale of our transects when density of either or both species was high. In the poorest habitat for macroalgae, red abalones seldom occurred on the same transects with red urchins. The results suggest that differences in density, depth, and food availability play an important role in the observed spatial patterns of red abalones and red sea urchins. Purple sea urchins were not correlated to either of the other two species' distributions. An intense fishery for red sea urchins appears to have had a positive effect on kelp availability, and abalone growth and abundance. Aerial photographs during the period of intense urchin fishing (from 1982 to 1989), showed a dramatic increase in the surface canopy. Similarly, during this period, size frequency distributions of fished red abalones show an increase in the number of individuals in larger size classes. Modal progression in abalone size frequency distributions suggests a faster growth rate during this period when compared with a growth study, at the same location, conducted during the pre-urchin fishery years. Ultimately, red sea urchin removal apparently led to an increase in red abalone abundance even at a site that was heavily fished by recreational abalone fishers. Meanwhile, at a nearby reserve site where kelp populations are lower, red abalones have declined in abundance as red sea urchins increased. Our results suggest the need for multi-species ecosystem-based approaches to management of these valuable resources.

Kaustuv, R., A. G. Collins, B. J. Becker, E. Begovic and J. M. Engle. 2003. Anthropogenic impacts and historical decline in body size of rocky intertidal gastropods in southern California. Ecology Letters. 6:205-211.

The diverse fauna and flora of rocky intertidal ecosystems are being impacted by the activities of rapidly increasing coastal populations in many regions of the world. Human harvesting of intertidal species can lead to significant changes in body sizes of these taxa. However, little is known about the temporal trajectories of such size declines and more importantly, the long-term effects of chronic human impacts. Furthermore, it is unclear whether sizes of species not directly targeted for harvesting are also declining through indirect effects. Here we use historical (extending back to 1869) and field survey data covering 200 km of mainland southern California coast to show that human activities have led to significant and widespread declines in body sizes of rocky intertidal gastropod species over the last century. These declines, initiated several decades ago, are continuing and contrary to expectation, they are not restricted to species harvested for human consumption. Data from the only national park in this area, where conservation laws are strictly imposed, demonstrate that negative ecological impacts can be ameliorated if existing laws are enforced.

Body size; gastropods; human impacts; Southern California.

Kellner, J. B., R. M. Nisbet and S. D. Gaines. 2008. Spillover from marine reserves related to mechanisms of population regulation. Theoretical Ecology. 1:117-127.

Spillover of fish from marine reserves to adjacent harvested waters may be mediated by density-independent movement, density-dependent movement, or both. If dispersal is by random movement, populations within the reserve must be regulated by density-dependent population growth (DDG). Density-dependent movement (DDM) can also regulate the population if accelerated emigration from a reserve to the surrounding fishing grounds leads to substantially increased mortality. Using spatially explicit models, we show that stock per unit area is bounded for DDG and increases with size for DDM. With DDG, spillover rate per unit area of reserve is maximized with reserves around 50% larger in linear dimension than the minimum size for population persistence. With DDM, spillover per unit area of reserve increases with reserve size. The results highlight the need for the mechanism of population regulation to be incorporated into theoretical and empirical investigations of marine reserve ecology.

Spillover; Density-dependent movement; Population regulation; Persistence; Marine protected area; Fishery yields

Kelly, S. and A. B. MacDiarmid. 2003. Movement patterns of mature spiny lobsters, Jasus edwardsii, from a marine reserve. New Zealand Journal of Marine and Freshwater Research. 37:149-158.

The maintenance of long-term associations with particular reef sites is likely to have contributed to the rebuilding of the spiny lobster population (Jasus edwardsii (Hutton) (Decapoda: Palinuridae)) in the Leigh Marine Reserve, in northeast New Zealand. Between 1983 and 1985, 429 lobsters were tagged underwater with western rock lobster tags and antennae tags. Underwater tagging and commercial traps were used to tag a further 737 lobsters with T-bar tags and antennae tags between 1994 and 1996. Twenty-one percent of lobsters resighted (n = 323) between 1983 and 1985 maintained their association with a 15 ha reef inside the reserve for 1–8 years. Site association tended to increase with female size, whereas site association in males was relatively constant until 130 mm carapace length, and then markedly increased. Legalsized lobster abundance fluctuated seasonally, suggesting that a proportion of the population undertook larger-scale movements beyond the reef. This was confirmed during a second tagging programme conducted between 1994 and 1996. About 30% of resighted lobsters (n = 212) moved 0.25–6 km from their tagging site and 20% crossed the boundary, either moving into or out of the reserve. These results indicate that although the Leigh Marine Reserve reduces spatial access to fishing grounds, a proportion of the lobster population moves out of the protected area and becomes susceptible to capture in the adjacent fishery.

Lobster; Jasus edwardsii; marine reserve; protected area; spillover; movements

Kido, J.S. and S.N. Murray. 2003. Variation in owl limpet Lottia gigantea population structures, growth rates, and gonadal production on southern California rocky shores. Marine Ecology Progress Series. 257: 111-124.

The size structures of Lottia gigantea populations were studied at 8 southern California sites, 4 of which were longstanding Marine protected areas (MPAs). Greater mean sizes and higher frequencies of larger individuals occurred at sites with lowest human visitation. Mean L. gigantea shell lengths (SLs) were negatively correlated with the number of visitors and collectors per 10 m of shoreline. Limpets never achieved SLs greater than 79.0 mm at any of our 8 sites, a size well below the maximum for this species. Mean SLs were comparable to sizes at other sites where L. gigantea is intensely collected. The presence of collectors, small mean SLs, and the absence of large limpets suggest that L. gigantea populations are affected by humans at our sites. Lower densities and higher frequencies of larger limpets were found in a subpopulation living on open-rock surfaces compared with a subpopulation occupying smaller, patch habitats within mussel beds. Larger limpets were mostly female and gonadal mass increased exponentially with SL in both subpopulations. Limpets <40 mm SL exhibited highly variable growth rates; however, limpets in patch habitats grew slower and produced less gonadal mass than limpets inhabiting open rocks, despite the availability of more microalgal food. Ages of the largest limpets in the open-rock subpopulation were estimated to be >8 yr. Given the age of larger limpets and the potential for collectors to remove larger individuals and shift populations towards smaller size structures, effective MPAs may take decades to reverse the effects of human impacts on L. gigantea populations in southern California.

Kinlan, B. P., S. D. Gaines and S. E. Lester. 2005. Propagule dispersal and the scales of marine community process. Diversity and Distributions. 11:139-148.

Benthic marine organisms are characterized by a bipartite life history in which populations of sedentary adults are connected by oceanic transport of planktonic propagules. In contrast with the terrestrial case, where ‘long distance dispersal’ (LDD) has traditionally been viewed as a process involving rare events, this creates the possibility for large numbers of offspring to travel far relative to the spatial scale of adult populations. As a result, the concept of LDD must be examined carefully when applied in a marine context. Any measure of LDD requires reference to an explicit ‘local’ scale, often defined in terms of adult population demography, habitat patchiness, or the average dispersal distance. Terms such as ‘open’ and ‘closed’ are relative, and should be used with caution, especially when compared across different taxa and systems. We use recently synthesized data on marine propagule dispersal potential and the spread of marine invasive species to draw inferences about average and maximum effective dispersal distances for marine taxa. Foremost, our results indicate that dispersal occurs at a wide range of scales in marine communities. The nonrandom distribution of these scales among community members has implications for marine community dynamics, and for the implementation of marine conservation efforts. Second, in agreement with theoretical results, our data illustrate that average and extreme dispersal scales do not necessarily covary. This further confounds simple classifications of ‘short’ and ‘long’ dispersers, because different ecological processes (e.g. range expansion vs. population replenishment) depend on different aspects of the dispersal pattern (e.g. extremes vs. average). Our findings argue for a more rigorous quantitative view of scale in the study of marine dispersal processes, where relative terms such as ‘short’ and ‘long’, ‘open’ and ‘closed’, ‘retained’ and ‘exported’ are defined only in conjunction with explicit definitions of the scale and process of interest. This shift in perspective represents an important step towards unifying theoretical and empirical studies of dispersal processes in marine and terrestrial systems.

 Biological invasions; dispersal kernel; invasive spread; larval retention; long-distance dispersal; marine conservation; pelagic larval duration; spatial ecology

Klein, C. J., A. Chan, L. Kircher, A. J. Cundiff, N. Gardner, Y. Hrovat, A. Scholz, B. E. Kendall and S. Airame. In Press. Striking a Balance between Biodiversity Conservation and Socioeconomic Viability in the Design of Marine Protected Areas. Conservation Biology.

The establishment of marine protected areas is often viewed as a conflict between conservation and fishing. We considered consumptive and nonconsumptive interests of multiple stakeholders (i.e., fishers, scuba divers, conservationists, managers, scientists) in the systematic design of a network of marine protected areas along California's central coast in the context of the Marine Life Protection Act Initiative. With advice from managers, administrators, and scientists, a representative group of stakeholders defined biodiversity conservation and socioeconomic goals that accommodated social needs and conserved marine ecosystems, consistent with legal requirements. To satisfy biodiversity goals, we targeted 11 marine habitats across 5 depth zones, areas of high species diversity, and areas containing species of special status. We minimized adverse socioeconomic impacts by minimizing negative effects on fishers. We included fine-scale fishing data from the recreational and commercial fishing sectors across 24 fisheries. Protected areas designed with consideration of commercial and recreational fisheries reduced potential impact to the fisheries approximately 21% more than protected areas designed without consideration of fishing effort and resulted in a small increase in the total area protected (approximately 3.4%). We incorporated confidential fishing data without revealing the identity of specific fisheries or individual fishing grounds. We sited a portion of the protected areas near land parks, marine laboratories, and scientific monitoring sites to address nonconsumptive socioeconomic goals. Our results show that a stakeholder-driven design process can use systematic conservation-planning methods to successfully produce options for network design that satisfy multiple conservation and socioeconomic objectives. Marine protected areas that incorporate multiple stakeholder interests without compromising biodiversity conservation goals are more likely to protect marine ecosystems.

conservation costs; conservation planning; fishing effort; fishing exclusion zones; marine biodiversity; marine reserves; Marxan; protected areas

Klein, C. J., A. Chan, L. Kircher, A. J. Cundiff, N. Gardner, Y. Hrovat, A. Scholz, B. E. Kendall and S. Airame. 2008. Striking a Balance between Biodiversity Conservation and Socioeconomic Viability in the Design of Marine Protected Areas. Conservation Biology. 22:691-700.

The establishment of marine protected areas is often viewed as a conflict between conservation and fishing. We considered consumptive and nonconsumptive interests of multiple stakeholders (i.e., fishers, scuba divers, conservationists, managers, scientists) in the systematic design of a network of marine protected areas along California's central coast in the context of the Marine Life Protection Act Initiative. With advice from managers, administrators, and scientists, a representative group of stakeholders defined biodiversity conservation and socioeconomic goals that accommodated social needs and conserved marine ecosystems, consistent with legal requirements. To satisfy biodiversity goals, we targeted 11 marine habitats across 5 depth zones, areas of high species diversity, and areas containing species of special status. We minimized adverse socioeconomic impacts by minimizing negative effects on fishers. We included fine-scale fishing data from the recreational and commercial fishing sectors across 24 fisheries. Protected areas designed with consideration of commercial and recreational fisheries reduced potential impact to the fisheries approximately 21% more than protected areas designed without consideration of fishing effort and resulted in a small increase in the total area protected (approximately 3.4%). We incorporated confidential fishing data without revealing the identity of specific fisheries or individual fishing grounds. We sited a portion of the protected areas near land parks, marine laboratories, and scientific monitoring sites to address nonconsumptive socioeconomic goals. Our results show that a stakeholder-driven design process can use systematic conservation-planning methods to successfully produce options for network design that satisfy multiple conservation and socioeconomic objectives. Marine protected areas that incorporate multiple stakeholder interests without compromising biodiversity conservation goals are more likely to protect marine ecosystems.

conservation costs; conservation planning; fishing effort; fishing exclusion zones; marine biodiversity; marine reserves; Marxan; protected areas

Klein, C. J., C. Steinback, A. J. Scholz, and H. P. Possingham. (2008). Effectiveness of marine reserve networks in representing biodiversity and minimizing impact to fishermen: a comparison of two approaches used in California. Conservation Letters 1: 44-51.

We compared the effectiveness of marine reserve networks designed using a numerical optimization tool with networks designed by stakeholders during the course of California's Marine Life Protection Act Initiative at representing biodiversity and minimizing estimated negative impacts to fishermen. We used the same spatial data representing biodiversity and recreational fishing effort that were used by the stakeholders to design marine reserves. In addition, we used commercial fishing data not explicitly available to the stakeholders. Networks of marine reserves designed with numerical optimization tools represented the same amount of each habitat, or more, and had less of an estimated impact on commercial and recreational fisheries than networks designed by the stakeholders. The networks designed by the stakeholders could have represented 2.0–9.5% more of each habitat with no additional impact on the fisheries. Of four different marine reserve proposals considered in the initiative, the proposal designed by fishermen was more efficient than the proposals designed by other stakeholder groups at representing biodiversity and minimizing impact to the fishing industry. These results highlight the necessity of using comprehensive information on fishing effort to design a reserve network that efficiently minimizes negative socioeconomic impacts. We recommend that numerical optimization tools support, not replace, the stakeholder driven reserve design process along California's northern and southern coasts to help accomplish two of the initiative's core objectives: (1) Protect representative and unique marine habitats, and (2) Minimize negative socioeconomic impacts. The involvement of stakeholders is necessary as additional factors important to reserve design can not be considered using a numerical optimization tool.

Biodiversity; systematic conservation planning; fishing; California's Marine Life Protection Act; marine reserve; Marxan; numerical optimization; socioeconomic; stakeholder

Koenig,C.C., F.C. Coleman, C.B. Grimes, G.R. Fitzhugh, K.M. Scanlon, C.T. Gledhill, M. Grace. 2000. Protection of fish spawning habitat for the conservation of warm-temperate reef-fish fisheries of shelf-edge reefs of Florida. Bulletin of Marine Science. 66(3): 593-616.

We mapped and briefly describe the surficial geology of selected examples of shelf-edge reefs (50-120 m deep) of the southeastern United States, which are apparently derived from ancient Pleistocene shorelines and are intermittently distributed throughout the region. These reefs are ecologically significant because they support a diverse array of fish and invertebrate species, and they are the only aggregation spawning sites of gag (Mycteroperca microlepis), scamp (M. phenax), and other economically important reef fish. Our studies on the east Florida shelf in the Experimental Oculina Research Reserve show that extensive damage to the habitat-structuring coral Oculina varicosa has occurred in the past, apparently from trawling and dredging activities of the 1970s and later. On damaged or destroyed Oculina habitat, reef-fish abundance and diversity are low, whereas on intact habitat, reef-fish diversity is relatively high compared to historical diversity on the same site. The abundance and biomass of the economically important reef fish was much higher in the past than it is now, and spawning aggregations of gag and scamp have been lost or greatly reduced in size. On the west Florida shelf, fishers have concentrated on shelf-edge habitats for over 100 yrs, but fishing intensity increased dramatically in the 1980s. Those reefs are characterized by low abundance of economically important species. The degree and extent of habitat damage there is unknown. We recommend marine fishery reserves to protect habitat and for use in experimentally examining the potential production of unfished communities.

Kritzer, J. P. 2004. Effects of noncompliance on the success of alternative designs of marine protected area networks for conservation and fisheries management. Conservation Biology. 18:1021-1031.

Studies examining the efficacy of marine protected areas (MPAs) rarely consider the potential for noncompliance. Violation of MPAs will typically occur near boundaries, so perimeter-to-area ratios will be important determinants of actual protection, suggesting that MPAs should be larger and likely fewer. If larval dispersal is highly localized, however, MPAs will need to be more numerous, widespread, and likely smaller in order to replenish many fished areas. Thus, there is a discord between the MPA network that would best achieve external replenishment and that which would maximize compliance. I investigated these competing criteria with a spatially structured model of a hypothetical marine fishery exploiting a sedentary reef-dwelling organism. With full compliance, a network of several small MPAs protects a population of similar size to that in a single large MPA and produces higher fishery yield across a range of fishing mortality rates. As noncompliance increases, however, the protected population in the network of several small MPAs approaches zero, whereas the single, large MPA population declines much less. Furthermore, at high levels of fishing mortality and noncompliance, yield with the network of several small MPAs begins to mirror that with no MPAs and drops below the yield with the single large MPA. Temporal variability in both the protected population size and yield are similar between the two designs with full compliance, but the single large MPA provides much greater stability in both metrics at high fishing mortality rates as noncompliance increases. My results highlight the important effects of noncompliance in realized MPA benefits and can explain why observed and expected effects might differ. Moreover, my results support a call for increased attention to rates of noncompliance and their ecological effects and greater collaboration among natural scientists, social scientists, managers, and stakeholders in understanding and altering illegal behavior.

Langlois, T. J. and W. J. Ballantine. 2005. Marine ecological research in New Zealand: Developing predictive models through the study of no-take marine reserves. Conservation Biology. 19:1763-1770.

New Zealand established its first no-take marine reserve more than 25 years ago. Twenty no-take marine reserves have now been created, although few of these are considered comparable. We considered whether existing conceptual models of population and community structure based only on data from exploited systems lack the baseline information of natural states necessary to make accurate predictions for new reserves. Three of the oldest and best-studied reserves are situated on the northeastern coast of New Zealand. These reserves are considered broadly comparable replicates, and research has shown the recovery of previously exploited predator populations and the reestablishment of trophic controls over community structure and productivity. None of the major changes was predicted when the reserves were created. All the observations from and experimental tests of hypotheses in these three ecologically comparable reserves have provided predictive models for future reserves. Recent surveys in newly created reserves, however, suggest that these models are bioregion and habitat specific. In these new reserves the recovery of previously exploited predators was predicted but did not always occur. Where trends were correctly predicted, the speed and amplitude of the changes were not accurately predicted. Research in New Zealand suggests that it is not yet possible to predict explicit outcomes for newly created reserves and less possible to predict detailed results for systems of reserves. Results from a representative system of reserves, including all major habitats within all bioregions and broadly comparable reserves, are needed. Such a system will enable the range and variety of natural ecosystem dynamics to be investigated and provide the controls necessary to measure the effects of exploitation.

Largier, J.L. 2003. Considerations in Estimating Larval Dispersal Distances From Oceanographic Data. Ecological Applications 13(1) Supplement: S71-S89.

Determination of larval dispersal distances and larval origins is a central challenge in contemporary marine ecology. In this work, the larval dispersal problem is discussed from the perspective of oceanography. Following formulation of the advection-diffusion model, the importance of scale is argued. When considering dispersion parameters at the appropriate population scales, advection is usually weaker than initially anticipated (and often used), and diffusion is stronger than typically used in model studies. Focusing attention on coastal populations, the importance of retention zones is described, and the more general existence of a coastal boundary layer is discussed. The coupling of crossshore and alongshore dispersion results in a nonlinear relation between alongshore dispersal distance and larval planktonic period for dispersion in a sheared flow. Thus, small changes in cross-shore dispersal, whether due to environmental differences or larval behavior result in significant differences in alongshore dispersal. Finally, the interplay between advection and diffusion is explored, showing the importance of adequately representing the diffusive effects that mitigate alongshore advection. In most cases, diffusion acts to prevent ''washout'' of a population and allows for more flexibility in the size and spacing of effective marine reserves. Future challenges must bring oceanographers and ecologists together around specific dispersal problems if there is to be a significant improvement in the notable absence of hard data in this field of enquiry.

Lasiak, T. 2006. Spatial variation in density and biomass of patellid limpets inside and outside of a marine protected area. Journal of Molluscan Studies. 72:137-142.

Although differences in the mean density, biomass and size of rocky intertidal biota inside and outside MPAs have been well documented, little is known about the variability in these attributes at different spatial scales. This topic merits investigation because it can influence the outcome of reproduction, competition and predation, and thereby affect the viability of populations. In this study, a nested sampling design was used to assess differences in density and biomass of seven species of patellid limpets at the scales of plots, sites and shores inside and outside a marine protected area (MPA) on the southeast coast of South Africa. At the scale of plots, significant variation was more common inside than outside the MPA. This probably reflects differences in the general pattern of space occupancy and quality of habitats available to limpets inside and outside the MPA. Significant variation at the scale of sites was rare. This suggests that either the processes contributing to variability at this scale counteract each other or that the sites were similar in terms of habitats and ecological processes. At the scale of shores, significant variation was more common in densities than in biomass, but both occurred with equal frequency inside and outside the MPA. Variation at this scale is probably driven by a combination of recruitment and/or mortality. Five species exhibited greater spatial variability inside than outside the MPA. The spatial patterns observed did not appear to be linked with differences in the mobility, habitat requirements or susceptibility of these species to exploitation. The lack of consistent patterns suggests that each species probably responds in a different way to the ecological processes operating at these spatial scales.

Leathwick, J., A. Moilanen, M. Francis, J. Elith, P. Taylor, K. Julian, T. Hastie and C. Duffy. 2008. Novel methods for the design and evaluation of marine protected areas in offshore waters. Conservation Letters. In Press:

There is strong international agreement on the need for marine protected areas to reverse pervasive human impacts on the oceans' biodiversity. However, their implementation is often hampered both by legal difficulties in defining reserves in international waters and the patchy nature of data in many offshore waters. We demonstrate the use of recent advances in statistical learning and conservation prioritization to produce MPA scenarios with varying costs and benefits for New Zealand's Exclusive Economic Zone, based on the analyses of distributions of 96 demersal fish species. MPAs based on our most cost effective scenario would deliver conservation benefits nearly 2.5 times greater than those from equivalent-sized areas recently implemented at the request of fishers, and at lower cost to them. Such results demonstrate the power of quantitative, knowledge-based prioritization approaches, which can be applied at high resolution and at oceanic scales.

Conservation planning; boosted regression trees; data mining; demersal fish; species distribution model; marine protected area; oceans; zonation.

Leathwick, J., A. Moilanen, M. Francis, J. Elith, P. Taylor, K. Julian, T. Hastie and C. Duffy. 2008. Novel methods for the design and evaluation of marine protected areas in offshore waters. Conservation Letters. 1:91-102.

There is strong international agreement on the need for marine protected areas to reverse pervasive human impacts on the oceans' biodiversity. However, their implementation is often hampered both by legal difficulties in defining reserves in international waters and the patchy nature of data in many offshore waters. We demonstrate the use of recent advances in statistical learning and conservation prioritization to produce MPA scenarios with varying costs and benefits for New Zealand's Exclusive Economic Zone, based on the analyses of distributions of 96 demersal fish species. MPAs based on our most cost effective scenario would deliver conservation benefits nearly 2.5 times greater than those from equivalent-sized areas recently implemented at the request of fishers, and at lower cost to them. Such results demonstrate the power of quantitative, knowledge-based prioritization approaches, which can be applied at high resolution and at oceanic scales.

Conservation planning; boosted regression trees; data mining; demersal fish; species distribution model; marine protected area; oceans; zonation

Leslie, H., E. N. Breck, F. Chan, J. Lubchenco, and B. A. Menge. (2005). Barnacle reproductive hotspots linked to nearshore ocean conditions. PNAS 102(30): 10534-10539.

Coastal marine ecosystems provide important ecosystem services to human populations worldwide. Understanding the contexts in which a species has markedly higher reproductive output is vital for effective management and conservation of these valuable and highly impacted systems. We documented reproductive hotspots along the Oregon coast for an ecologically significant marine invertebrate, the intertidal barnacle Balanus glandula. Greater larval production in both natural and experimental populations was associated with higher primary productivity in the adjacent nearshore ocean, providing strong evidence for bottom-up forcing. Mean cumulative larval production per 100 cm2 in natural barnacle populations in the region of higher primary productivity was almost 5_ that of populations in the less productive region. Mean estimated larval production per individual in experimental populations in the region of higher primary productivity was >2_ that of populations in the region of lower productivity, and mean larval production per 100 cm2 was >120_ greater in the region of higher productivity. Our results highlight the importance of spatial heterogeneity in reproduction and other ecological processes in the marine environment and provide a mechanistic basis for evaluating the relative contributions of different sites when designing marine reserves and other protected areas. Our findings also advance the understanding of the role of bottom-up influences on population and community dynamics and contribute data for the next generation of models of marine community dynamics.

Balanus glandula, bottom-up effects, intertidal ecosystems, marine ecology, marine reserves

Leslie, H., M. Ruckelshaus, I.R. Ball, S. Andelman, and H.P. Possingham. 2003. Using Siting Algorithms in the Design of Marine Reserve Networks. Ecological Applications 13(1) Supplement: S185-S198.

Using benthic habitat data from the Florida Keys (USA), we demonstrate how siting algorithms can help identify potential networks of marine reserves that comprehensively represent target habitat types. We applied a flexible optimization tool-simulated annealing-to represent a fixed proportion of different marine habitat types within a geographic area. We investigated the relative influence of spatial information, planning unit size, detail of habitat classification, and magnitude of the overall conservation goal on the resulting network scenarios. With this method, we were able to identify many adequate reserve systems that met the conservation goals, e.g., representing at least 20% of each conservation target (i.e., habitat type) while fulfilling the overall aim of minimizing the system area and perimeter. One of the most useful types of information provided by this siting algorithm comes from an ''irreplaceability analysis,'' which is a count of the number of times unique planning units were included in reserve system scenarios. This analysis indicated that many different combinations of sites produced networks that met the conservation goals. While individual 1-km2 areas were fairly interchangeable, the irreplaceability analysis highlighted larger areas within the planning region that were chosen consistently to meet the goals incorporated into the algorithm. Additionally, we found that reserve systems designed with a high degree of spatial clustering tended to have considerably less perimeter and larger overall areas in reserve-a configuration that may be preferable particularly for sociopolitical reasons. This exercise illustrates the value of using the simulated annealing algorithm to help site marine reserves: the approach makes efficient use of available resources, can be used interactively by conservation decision makers, and offers biologically suitable alternative networks from which an effective system of marine reserves can be crafted.

Lester, S. E., K. L. McLeod, H. Tallis, M. Ruckelshaus, B. S. Halpern, P. S. Levin, F. P. Chavez, C. Pomeroy, B. J. McCay, C. Costello, S. D. Gaines, A. J. Mace, J. A. Barth, D. L. Fluharty, J. K. Parrish. (2010). Science in support of ecosystem-based management for the US West Coast and beyond. Biological Conservation: 1-12.

Declining ocean health, increasing human demands on marine ecosystems, and a history of management focused on individual activities, species or sectors has led to calls for more comprehensive, integrated management that considers entire coupled social-ecological systems. This transition to ecosystem-based management (EBM) for the oceans will certainly face a number of hurdles, and many practitioners struggle with how to move forward with EBM. In this paper, we assess whether the necessary science exists to support EBM. Specifically, we evaluate the state of the social and natural sciences for three research areas that are critical to EBM: (1) ecosystem services, (2) cumulative impacts, and (3) ecosystem variability and change. For each of the three research areas, we describe its importance to EBM and assess existing and emerging information and application of this knowledge, focusing on the US West Coast. We conclude that available science is not the bottleneck for moving forward with comprehensive EBM for this region, although we highlight important remaining knowledge gaps, particularly within the social sciences. Given imperfect and uncertain knowledge, EBM calls for an adaptive management approach, starting with readily available information, and continuously adapting as new information emerges. This synthesis can serve as a basis for comparison for other regions; it provides guidance for organizing information in support of EBM and outlines many novel and broadly applicable scientific approaches.

Ecosystem-based management, Marine Ecosystem services, Cumulative impacts, Ecosystem variability

Lester, S. E., B. I. Ruttenberg, S. D. Gaines and B. P. Kinlan. 2007. The relationship between dispersal ability and geographic range size. Ecology Letters. 10:745-758.

There are a variety of proposed evolutionary and ecological explanations for why some species have more extensive geographical ranges than others. One of the most common explanations is variation in species dispersal ability. However, the purported relationship between dispersal distance and range size has been subjected to few theoretical investigations, and empirical tests reach conflicting conclusions. We attempt to reconcile the equivocal results of previous studies by reviewing and synthesizing quantitative dispersal data, examining the relationship between average dispersal ability and range size for different spatial scales, regions and taxonomic groups. We use extensive data from marine taxa whose average dispersal varies by seven orders of magnitude. Our results suggest dispersal is not a general determinant of range size, but can play an important role in some circumstances. We also review the mechanistic theories proposed to explain a positive relationship between range size and dispersal and explore their underlying rationales and supporting or refuting evidence. Despite numerous studies assuming a priori that dispersal influences range size, this is the first comprehensive conceptual evaluation of these ideas. Overall, our results indicate that although dispersal can be an important process moderating species' distributions, increased attention should be paid to other processes responsible for range size variation.

Biogeography; colonization; dispersal; geographical distribution; marine; pelagic larval duration; range size; selection; speciation

Lester, S.E. and B. S. Halpern. 2008. Biological responses in marine no-take reserves versus partially protected areas. Marine Ecology Progress Series. 367:49-56.

Marine Protected Areas (MPAs) are a common tool for conserving and managing marine and coastal ecosystems. MPAs encompass a range of protection levels, from fully protected no-take reserves to restriction of only particular activities, gear types, user groups, target species, or extraction periods. There is a growing body of scientific evidence supporting the ecological benefits of full reserve protection, but it is more difficult to generalize about the effects of other types of MPAs, in part because they include a range of actual protection levels. However, it is critical to determine whether partial protection and no-take reserves provide similar ecological benefits given potential economic costs of lost fishing grounds in no-take areas, common sociopolitical opposition to full protection, and promotion of partially protected areas as a compromise solution in ocean zoning disputes. Here we synthesize all empirical studies comparing biological measures (biomass, density, species richness, and size of organisms) in no-take marine reserves and adjacent partially protected and unprotected areas across a range of geographic locations worldwide. We demonstrate that while partially protected areas may confer some benefits over open access areas, no-take reserves generally show greater benefits and yield significantly higher densities of organisms within their boundaries relative to partially protected sites nearby.

Marine reserves; Marine protected areas; Protection level; Conservation; Ocean zoning

Lester, S. E., B. S. Halpern, K. Grorud-Colvert, J. Lubchenco, B. I. Ruttenberg, S. D. Gaines, S. Airame and R. R. Warner. 2009. Biological effects within no-take marine reserves: a global synthesis. Marine Ecology Progress Series. 384:33-46.

The study and implementation of no-take marine reserves have increased rapidly over the past decade, providing ample data on the biological effects of reserve protection for a wide range of geographic locations and organisms. The plethora of new studies affords the opportunity to reevaluate previous findings and address formerly unanswered questions with extensive data syntheses. Our results show, on average, positive effects of reserve protection on the biomass, numerical density, species richness, and size of organisms within their boundaries which are remarkably similar to those of past syntheses despite a near doubling of data. New analyses indicate that (1) these results do not appear to be an artifact of reserves being sited in better locations; (2) results do not appear to be driven by displaced fishing effort outside of reserves; (3) contrary to often-made assertions, reserves have similar if not greater positive effects in temperate settings, at least for reef ecosystems; (4) even small reserves can produce significant biological responses irrespective of latitude, although more data are needed to test whether reserve effects scale with reserve size; and (5) effects of reserves vary for different taxonomic groups and for taxa with various characteristics, and not all species increase in response to reserve protection. There is considerable variation in the responses documented across all the reserves in our data set variability which cannot be entirely explained by which species were studied. We suggest that reserve characteristics and context, particularly the intensity of fishing outside the reserve and inside the reserve before implementation, play key roles in determining the direction and magnitude of the reserve response. However, despite considerable variability, positive responses are far more common than no differences or negative responses, validating the potential for well designed and enforced reserves to serve as globally important conservation and management tools.

Marine reserves; Temperate; Tropical; Fishes; Invertebrates; Algae; Marine Protected Area; Conservation

Levin, P. S., I. Kaplan, R. Grober-Dunsmore, P. M. Chittaro, S. Oyamada, K. Andrews and M. Mangel. 2009. A framework for assessing the biodiversity and fishery aspects of marine reserves. Journal of Applied Ecology. 46:735-742.

  1. Resource management agencies are often charged with managing natural resources for economic and social goals, while also protecting and conserving biodiversity and ecosystem function. However, this may not always be possible. Ecosystem-based management is frequently suggested as a way to achieve multiple objectives in resource management and requires that tradeoffs among conflicting objectives be identified and an effective means to utilize these trade-offs developed.
  2. We examine the relationship between area and species richness in a diverse assemblage of fishes along the US West Coast and then use parameters from this relationship as input for a model that considers trade-offs between fisheries yield and the number of species protected by different management strategies.
  3. The species area relationship (S = cAz) for fishes along the US Pacific coast is well described by the relationship S = 16·18A0·226.
  4. There are nearly linear trade-offs between diversity and yield when fishing effort is low. However, the trade-offs become nonlinear as fishing effort increases and imposing MPAs increases both the conservation and fisheries value of the system when the system is overfished.
  5. Synthesis and applications. Solving conflicts between fisheries and conservation requires attention as to how conservation benefits accrue as fishing effort is reduced. However, scientists often lack quantitative information about the trade-offs inherent in human activities such as fisheries. The approach we develop here can begin to help frame the questions to be posed and evaluate the likely consequences of different management options.

California current; ecosystem-based management; fisheries management; marine protected area; species-area relationship

Levin, S. A. and J. Lubchenco. (2008). Resilience, Robustness, and Marine Ecosystem-based Management. BioScience 58(1): 27-32.

Marine ecosystems provide essential services to humans, yet these services have been diminished, and their future sustainability endangered, by human patterns of exploitation that threaten system robustness and resilience. Marine ecosystems are complex adaptive systems composed of individual agents that interact with one another to produce collective effects, integrating scales from individual behaviors to the dynamics of whole systems. In such systems, small changes can be magnified through nonlinear interactions, facilitating regime shifts and collapses. Protection of the services these ecosystems provide must therefore maintain the adaptive capacities of these systems by preserving a balance among heterogeneity, modularity, and redundancy, tightening feedback loops to provide incentives for sound stewardship. The challenge for management is to increase incentives to individuals, and tighten reward loops, in ways that will strengthen the robustness and resilience of these systems and preserve their ability to provide ecosystem services for generations to come.

complex adaptive systems, scale, resilience, robustness, ecosystem management

Lindberg, D. R., J. A. Estes and K. I. Warheit. 1998. Human influences on trophic cascades along rocky shores. Ecological Applications. 8:880-890.

A three-trophic-level interaction among American Black Oystercatchers (Haematopus bachmani), limpets (Lottia spp.), and erect fleshy algae in rocky intertidal communities of central and southern California was documented via manipulative and ''natural'' experiments. Removal of the territorial limpet (Lottia gigantea) initially caused large increases in the percent cover of erect fleshy algae, followed by a more gradual increase in density of small limpets (Lottia spp.) and a decline in algal cover. Algal cover increased following the removal of small limpets at the sites from which L. gigantea had been removed earlier, thus demonstrating that the large and small limpets had similar inhibitory effects on plant populations. A comparison of sites with and without oystercatchers showed that L. gigantea occupied substrate inclinations in proportion to their availability at sites where oystercatchers were rare, whereas the distribution of L. gigantea was skewed toward vertically inclined substrates where oystercatchers were common. Survival rates of limpets translocated to horizontal and vertical substrates were similar in sites lacking oystercatcher predation, but were much lower on horizontal substrates where oystercatchers were common. Our results are consistent with those from several prior studies in demonstrating that shorelines frequented by humans typically lack oystercatchers. Humans also exploit L. gigantea and reduce populations to low densities of small individuals. These findings may explain why the midlittoral zone of rocky intertidal communities in western North America are so often dominated by high population densities of small limpets.

algae; California; grazing; Haematopus bachmani; historical biology; limpets; Lottia gigantea; natural experiments; oystercatchers; predation; refuges; territoriality; human disturbances

Lindholm, J., P. Auster and P. Valentine. 2004. Role of a large marine protected area for conserving landscape attributes of sand habitats on Georges Bank (NW Atlantic). Marine Ecology Progress Series. 260:61-68.

Mobile fishing gear reduces seafloor habitat complexity through the removal of structure-building fauna, e.g. emergent organisms that create pits and burrows, as well as by smoothing of sedimentary bedforms (e.g. sand ripples). In this study, we compared the relative abundance of microhabitat features (the scale at which individual fish associate with seafloor habitat) inside and outside of a large fishery closed area (6917 km2) on Georges Bank. Starting in late 1994, the closed area excluded all bottom tending fishing gear capable of

capturing demersal fishes. A total of 32 stations were selected inside and outside of the closed area in sand habitats. Video and still photographic transects were conducted at each station using the Seabed Observation and Sampling System (SEABOSS). Seven common (i.e. featureless sand, rippled sand, sand with emergent fauna, bare gravelly sand, gravelly sand with attached-erect fauna, whole shell, shell fragment) and 2 rare (sponges, biogenic depressions) microhabitat types were compared separately. Results showed significant differences in the relative abundance of the shell fragment and sponge microhabitat types between fished and unfished areas. The lack of differences for the other microhabitats may indicate that the level of fishing activity in the area is matched by the system’s ability to recover.

Microhabitat; Fishing gear; Fishing impacts; Photography; Video

Love, M. S., D. M. Schroeder and W. H. Lenarz. 2005. Distribution of boccacio (Sebastes paucispinis) and cowcod (Sebastes levis) around oil platforms and natural outcrops off California with implications for larval production. Bulletin of Marine Science. 77:397-408.

There is increasing evidence that some California oil platforms form important habitats for a number of economically important fishes. We asked to what extent might platforms be important as producers of larvae of several overfished species (bocaccio, Sebastes paucispinis Ayres, 1854 and cowcod, Sebastes levis Eigenmann and Eigenmann, 1889) on a local or regional basis. We compared adult densities and potential larval production of these species at platforms and natural outcrops in California. Densities of mature bocaccio and cowcod were highly variable among survey sites, but were generally very low at both natural reefs and platforms. However, the mean densities for both species were higher around platforms than at natural reefs. Two of the three platforms (Gail and Hidalgo) that harbored mature bocaccio had larger mature individuals than did any natural reef. Platform Gail had by far the highest densities of both mature bocaccio and cowcod of any natural or human- made habitat and the potential larval production of both species at Platform Gail was much higher than at any other site surveyed. We estimated the removal of Platform Gail would be the equivalent of removing 12.57 ha of average-producing natural habitat in southern California for cowcod or 29.24 ha of average-producing natural habitat for bocaccio. These results may have implications for the platform decommissioning process.

Lowe, C. G., D. T. Topping, D. P. Cartamil and Y. P. Papastamatiou. 2003. Movement patterns, home range, and habitat utilization of adult kelp bass Paralabrax clathratus in a temperate no-take marine reserve. Marine Ecology Progress Series. 256:205-216.

Home range, activity patterns, site fidelity and habitat preference of the kelp bass Paralabrax clathratus were determined from 12 adult fish tracked using acoustic telemetry within a temperate no-take marine reserve (0.13 km2). Home range sizes ranged from 33 to 11 224 m2, averaging 3349 ± 3328 m2 (±SD), but did not correlate with fish size. Fish were active and occupied similar-sized activity spaces during both day and night. Kelp bass exhibited a high degree of site fidelity, remaining resident in core areas for up to 3 yr. Relative to the total amount of available habitat, kelp bass showed a habitat selection preference for rock boulder, rock rubble and kelp habitat. These habitats offer high vertical relief, shade and large holes for shelter, and may attract and facilitate prey capture. Average home range size was 3% of the area of the reserve. Only 1 of 12 tracked fish crossed the reserve boundary, but this accounted for less than 5% of the fish’s time. Natural habitat breaks along the reserve boundary may have further limited adult kelp bass movements. The small home ranges and high site fidelity of kelp bass in this reserve indicate that the reserve is effective in protecting the resident adult stock.

Movements; Diel; Site fidelity; Marine reserves; Activity; Habitat preference

Mace, A. J. and S. G. Morgan. 2006. Larval accumulation in the lee of a small headland: implications for the design of marine reserves. Marine Ecology Progress Series. 318:19-29.

Oceanic currents and larval accumulation potentially have large impacts on the choice of locations for marine reserves. Larval settlement of benthic invertebrates was greater in the lee than on the windward side of a small headland during the height of upwelling in central California during 2001 and 2002. Strong upwelling during the study was indicated by mean seasonal Bakun indices of 149 to 176 m3 s-1 per 100 m of coastline in 2001–2002. Weekly sampling of near-surface and near bottom settlement in the lee of Bodega Head from August 2000 to September 2001 revealed that most larvae of 7 crab taxa settled during spring and summer, which coincides with the upwelling season. Comparison of sites in the protected (lee) and exposed (windward) sides of the headland (2 sites each) during the peak settlement season in 2001 showed that most larvae settled in the lee of the headland, including 91% of crabs, 89% of barnacles, and 80% of mussels in weekly samples. During 2002, weekly sampling at 1 protected and 1 exposed site also demonstrated that most settlement occurred in the lee of the headland, including 74% of crabs, 82% of barnacles, and 65% of mussels. Crabs settled mostly at the surface, whereas barnacles and mussels primarily settled near the bottom, indicating that postlarvae in both surface and bottom waters accumulate in the lee of the headland. Larval accumulation zones should be included in networks of marine reserves to supply adult populations with propagules in recruitment-limited upwelling regions.

Larval retention; Larval dispersal; Headland eddy; Recirculation; Marine reserve; Meroplankton

Malvadkar, U. and A. Hastings. 2008. Persistence of mobile species in marine protected areas. Fisheries Research. 91:69-78.

A central goal of many marine protected areas is ensuring the persistence of fish populations, which depends on the life history characteristics and movement patterns of individual species. While previous studies have focused on species where adults are sedentary, the current study examines an age-structured diffusion model for a one-species system in a single spatial dimension. We define persistence as a positive growth rate for small populations and determine conditions that will yield a positive growth rate.We find that the minimum fraction of habitat needed to be off-limits to fishing depends on two dimensionless parameters representing the net birth rate in the reserve, measured in the time it takes to move the length of the habitat, and the net death rate in the fished area, in that same time. Of the two parameters, natural population growth rate has a larger impact on reserve size than the net death rate due to fishing, although their ratio is useful for determining reserve size. These results suggest that reserves are appropriate for mobile species having at least one of several qualities: (1) small movement rates, (2) high birth rates relative to fishing rates or (3) large habitat sizes.

Diffusion; Age-structured model; Marine protected areas; Marine reserves

Mangel, M. 1998. No-take areas for sustainability of harvested species and a conservation invariant for marine reserves. Ecology Letters. 1:87-90.

Various kinds of no-take areas (refuges, reserves) are gaining attention as conservation tools. The efficacy of reserves can be considered from the perspectives of providing baseline data sets, protecting the stock, maximizing yield to the fishery, or some combination of these. Regardless of the measure of effectiveness of a reserve, practical application requires the development of techniques for settling operational and policy questions such as how large a reserve should be. A simple model, involving population growth and harvest, is used to explore how the fraction of habitat assigned to a reserve affects the sustainability of a take and to frame the trade-off between control of harvest outside of the reserve and the size of the reserve. This exploration also leads to the discovery of a robust conservation invariant for reserves.

Mangel, M. 2000. On the fraction of habitat allocated to marine reserves. Ecology Letters. 3:15-22.

The case for marine reserves is strengthening, and both deterministic and stochastic calculations show that fisheries management using reserves may achieve harvests comparable with management without reserves. Thus, depending upon the metric used, reserves need not disadvantage harvest. Reserves provide a buffer that increases the chances of sustainability of the stock, and thus the fishery. In this paper, I develop methods (deterministic and stochastic) that allow one to determine how much habitat needs to be set aside as reserve, once societal decisions concerning the goals of reserves are made. The answer to the question: "how much habitat needs to be allocated to reserves" is not a simple single number. Rather, it is a procedure that can be employed once biological, operational and social information are provided. The methods also apply to reserves used to aid stock recovery.

Marine Protected Areas; Marine Reserves; Sustainable Fisheries

Martell, S.J.D., C.J. Walters, S.S. Wallace. 2000. The use of marine protected areas for conservation of lingcod (Ophiodon elongatus). Bulletin of Marine Science 66(3): 729-743.

Recreational and commercial overharvesting has led to a 90% reduction in the Strait of Georgia lingcod (Ophiodon elongatus) population. Two small marine protected areas (MPAs), accounting for less than 1% of the area, in Howe Sound attract spawning lingcod. Densities of large spawning animals are higher in both of the MPAs than on surrounding reefs that are open to fishing and are significantly higher in the MPA with artificial habitat. An in-situ tagging study indicates animals leave the shallow study sites, at least seasonally. Such small-scale movements must be taken into consideration when the size and location of marine reserves are selected. Fishes with high exchange rates, large home ranges, or seasonal migrations for spawning (such as lingcod) require large marine reserves. We have developed a general spatial model for estimating effects of age-dependent seasonal migration and dispersal on harvest mortality rates, including the effects of fishing effort movement in response to local abundance changes. Simulations suggest the MPAs are too small to provide year-round protection of lingcod from anglers.

McClanahan, T. R. and M. S. 2000. Spillover of expolitable fishes from a marine park and its effect on the adjacent fishery. Ecological Applications. 10:1792-1805.

The role of a marine protected area in enhancing local fisheries, through the emigration or spillover of exploitable fishes, was studied in a coral reef park (Mombasa Marine Park, Kenya) and fishery over a seven-year period during a time when the park's border changed and pull seines were eliminated. We measured catches before and after the park's establishment and during the management changes and compared these catches with the unmanaged side of the park. Additionally, we placed baited traps on both sides of the park over a full tidal cycle which allowed us to measure the spillover from the park compared to the deeper, rougher, and less fished reef edge. The total wet mass of catches per trap, the mean size of the trapped fish, and the number of fish species caught per trap declined as a function of the distance away from the park edge on both the southern and northern sides. However, this relationship was truncated on the unmanaged side which also had smaller catches, smaller fish, and fewer species than the managed side. Trap fishers on the managed side adapted to the spillover by increasing the traps per fisher, which had the effect of reducing the catch per trap. Tides and reef morphology also appeared to interact and influenced catches, but we found no relationships between catches and benthic substratum cover, which was usually dominated by seagrass and sand. Spillover from the deeper reef edge was evident for the managed but not the unmanaged side of the park, but may be due to differences in reef morphology interacting with tidal patterns rather than management. On the managed side, the park significantly increased the catch per fisher and catch per area by >50%, but even after the park's size was reduced, the total catch was reduced by ~30%. The reduced park was still ~50% of the total area. Consequently, the catch per area increase was insufficient to compensate for the lost area over this early period of the park's establishment. Spillover was greatest for the dominant fisheries species. These were moderately vagile species in the rabbitfish (Siganidae; herbivores), emperors (Lethrinidae; carnivores), and surgeonfish (Acanthuridae; herbivores) families, which had instantaneous emigration rates from the park to the reserve fishing ground of ~0.5. Our field survey, combined with previous modeling studies, based on adult emigration rates from marine reserves, suggests that tropical fisheries dominated by rabbitfish, emperors, and surgeonfish should be enhanced by closed areas of ~10-15% of the total area. The optimal protected area may increase if larval export is important, but the predicted response should not be measurable for >10 years, beyond the length of our study, as breeding stock develop inside protected areas.

Acanthuridae; adaptive management; coral reefs; dispersal; emigration rates; integrated coastal area management; Lethrinidae; marine fisheries reserves; marine protected areas; Siganidae; tropical fisheries

McConnaughey, R. A., D. A. Armstrong, B. M. Hickey, and D. R. Gunderson. (1994). Interannual variability in coastal Washington Dungeness crab (Cancer magister) populations: larval advection and the coastal landing strip. Fisheries Oceanography 3(1): 22-38.

Substantial and unexplained variations in abundance characterize US west coast populations of Dungeness crab, Cancer mugister. It is likely that this variability reflects oceanic advection of larvae given the dynamics of the California Current system, the protracted (4-5 months) pelagic larval phase and the restrictive nature of juvenile habitat requirements. We compare 40 years of Ekman transport vectors during January-May ( 1947-1986) with time-lagged and stratified commercial landings for coastal Washington (195 1-1990). Persistent landward and net northward flow characterized the circulation of near-surface waters during the larval periods studied. A mechanism for progressive seaward transport of larvae through ontogeny, as proposed by others, was not apparent. Overall, above- (below-) average year classes were associated with relatively weak (strong) northward transport and, to a lesser degree, strong (weak) landward transport. Based on these analyses and in consideration of the prevailing coastal circulation, we propose that the relative magnitude of C. mugister juvenile recruitment and, hence, incoming year class strength, reflects: (1) the proportion of larvae retained within a relatively narrow (5 15 km) and heterogeneous 'coastal landing strip', (2) the availability of suitable substrate within the coastal landing strip at time of settlement and (3) the magnitude of downstream advective losses (export) of larvae from the California-Oregon-Washington coastal system. Based on a consideration of the physics of the California Current system and the larval biology of the species, significant linkage of Dungeness crab populations along the west coast of North America is likely.

recruitment, Dungeness crab, larval advection, California Current system

McCormick, T. B., L. M. Buckley, J. Brogan and L. M. Perry. 2008. Drift macroalgae as a potential dispersal mechanism for the white abalone Haliotis sorenseni. Marine Ecology Progress Series. 362:225-232.

The endangered white abalone Haliotis sorenseni, Bartsch 1940 is distributed throughout the Southern California Bight and northern Baja California, a range of 900 km, despite a short 5 d larval dispersal stage. Casual observation of 1 to 3 yr old white abalone during routine monitoring of hatchery-raised individuals revealed behavior that may provide an alternative long-range dispersal mechanism. Two new behaviors were observed during this study. Juvenile and young adult white abalone assume a 'standing' position in response to the presence of a drifting substrate. Many then 'climb' onto fragments of drifting kelp Macrocystis pyrifera, other benthic macroalgae, and drifting substrates in flumes. Such behavior has not previously been described for any abalone species. To test the frequency and duration of the behavior, fragments of macroalgae typically found in white abalone habitat were passed down a flume stocked with juvenile and young adult white abalone. An average of more than 6% of the abalone climbed onto M. pyrifera during the short 20 s transit time of the algae down the flume. Significantly more abalone (p < 0.01) climbed onto M. pyrifera than any other test substrate, including 2 other macroalgae species and a rubber test substrate. Trials with red abalone resulted in no instances of standing or climbing behavior. Duration of white abalone attachment on kelp suspended in the water column in the laboratory was prolonged (up to 51 d in tests). Such behavior in the wild could result in transport distance of 100s of km. The movement of the drift algae may bring it and the rafting abalone to isolated rock outcrops that are adult habitat. Algal rafting could potentially transport individual or groups of juvenile and early adult abalone far beyond the range of larval dispersal.

Abalone; Drift algae; Rafting; Dispersal; Benthic fauna; Haliotis sorenseni

Meyer, C. G. 2007. The impacts of spear and other recreational fishers on a small permanent Marine Protected Area and adjacent pulse fished area. Fisheries Research. 84:301-307.

I used shoreline creel surveys to quantify fishing activities in and around a small (0.34 km2) Marine Protected Area (MPA) in Hawaii (Waikiki Marine Life Conservation District). Spear fishing and shoreline pole & line fishing (angling) were the dominant fishing activities at Waikiki. Spear fishing had a greater overall impact on reef fishes than shoreline pole & line fishing, accounting for 70% of the total reef fish harvest at Waikiki, despite accounting for only 25% of fishing activities observed. Fishing activities at Waikiki were unevenly distributed in space and time. The MPA experienced minor illegal fishing and was located between an area of high diurnal spear fishing effort and an area of generally low fishing effort. This pattern of fishing activities allows jacks and goatfishes to evade capture despite nightly excursions from the MPA into fished areas, and may partly explain why these fishes remain more abundant and larger inside the Waikiki MPA than in surrounding fished areas. Quantifying fishing activities at MPA sites can provide valuable insight into how these areas function, and this information can be used to improve MPA design and effectiveness.

Marine Protected Area; Fishing impacts; Spear fishing

Micheli, F. and B. S. Halpern. 2005. Low functional redundancy in coastal marine assemblages. Ecology Letters. 8:391-400.

The relationship between species and functional diversity remains poorly understood for nearly all ecosystem types, yet determining this relationship is critically important for developing both a mechanistic understanding of community assembly and appropriate expectations and approaches to protecting and restoring biological communities. Here we use two distinct data sets, one from kelp forests in the Channel Islands, California, and one from a global synthesis of marine reserves, to directly test how variation in species diversity translates into changes in functional diversity. We find strong positive relationships between species and functional diversity, and increased functional diversity of fish assemblages coinciding with recovery of species diversity in marine reserves, independent of the method used for classifying species in functional groups. These results indicate that low levels of redundancy in functional species traits exist across a suite of marine systems, and that fishing tends to remove whole functional groups from coastal marine ecosystems.

Coastal marine ecosystems; diversity; ecological functions; fish assemblages; functional redundancy; human impacts; marine protected areas; marine reserves; recovery; resilience

Micheli, F., B. S. Halpern, L. W. Botsford and R. R. Warner. 2004. Trajectories and correlates of community change in no-take marine reserves. 2004. 14:1709-1723.

Marine reserves are a spatial approach to marine management and conservation aimed at protecting and restoring multispecies assemblages and the structure and function of marine ecosystems. We used meta-analyses of published data to address the questions of how and over what time frames marine assemblages change within no-take marine reserves as they recover from fishing and other human uses. We used 20 studies of coastal fish assemblages from 31 temperate and tropical locations, reporting abundances, and in some cases biomass, of 10-134 species from reserve and reference conditions (i.e., conditions in nearby fished sites or before reserve establishment) spanning 1-25 years of protection. Synthesis of data from these diverse sets of assemblages showed that: (1) a species' level of exploitation, trophic level, and the duration of protection through the no-take reserve explain small but significant amounts of variation in individual species responses to protection, with only species that are targeted by fishing or by aquarium trade showing overall enhanced abundances in protected areas, and increasing positive effects of protection on abundances at top trophic levels through time; (2) up to a third of species in different studies (19% on average) appeared to be negatively affected by protection, indicating that indirect effects of protection through competitive or predatory interactions may be common; and (3) variation and lags in species responses to protection resulted in protected assemblages diverging from reference conditions, with greater proportions of total fish biomass at top trophic levels in protected compared to fished assemblages. These results indicate that marine reserves are effective in enhancing local abundances of exploited species and restoring the structure of whole communities, though these changes occur through a series of transient states and, for some communities, over long time frames (decades). In contrast with the more predictable increases of aggregate community variables such as total abundance and biomass, individual species and community structure exhibited broad variation in their responses to protection. Marine protected areas represent multiple human-exclusion "experiments," replicated in a variety of ecosystem types and geographic locations, providing key insights on community-wide impacts of the removal of human extraction. Long-term monitoring of community trajectories in marine protected areas and modeling studies scaling up local effects to relevant spatial and temporal scales are needed to increase our ability to protect and restore whole marine systems and to set realistic targets for the conservation and restoration of specific assemblages.

coastal fish assemblages; community change; community structure; fishing impacts; human impacts; indirect effects; marine protected areas; marine reserves; meta-analysis; recovery; temporal trajectories; trophic cascades

Micheli, F., P. Amarasekare, J. Bascompte and L. R. Gerber. 2004. Including species interations in the design and evaluations of marine reserves: some insights from a predator-prey model. Bulletin of Marine Science. 74:653-669.

Conservation of marine species through fisheries management and no-take marine reserves have focused primarily on single species, but such protection may influence the target species' predators, prey, competitors, or mutualists. Conversely, successful protection may depend on responses of these other species. Empirical data and previous theory indicate that fisheries status and life-history attributes strongly influence species' responses to protection. Both direct effects and indirect effects of protection (through species interactions) have been documented. A predator-prey model depicting the dynamics of two species in a two-patch habitat (a no-take reserve and a fished area) revealed conditions under which the predator and prey may decline after reserve establishment. Not surprisingly, model results suggest that management scenarios and life-history traits leading to high predator population growth are more likely to produce prey declines following reserve establishment. Interestingly, trade-offs between enhancing predator and enhancing prey occurred at low fishing intensities regardless of the prey and predator life-history traits. At high fishing rates, reserve establishment generally outweighed predation effects and resulted in increased abundance of both predator and prey. Simple spatial models can help determine the range of possible responses of interacting species to protection and can yield some general insights for their management.

Milazzo, M., R. Chemello, F. Badalamenti, R. Camarda, S. Riggio. (2002). The impact of human recreational activities in marine protected areas: what lessons should be learnt in the Mediterranean Sea?. Marine Ecology 23(Supplement 1): 280-290.

The aesthetic appeal of marine reserves and the facilities provided, together with the increased public awareness of nature, all contribute to creating massive tourism in MPAs. Human activities are being changes inside MPAs in two ways: humans as top predators are generally being removed, but in turn they could come back at great numbers as visitors. Many authors have studied the impact of visitors, and the results highlight that all consequences can be very substantial and may represent a severe threat to the overall diversity of marine communities. To date, the documented effects of human recreational activities on natural communities are restricted to assessing the consequences of trampling over intertidal and upper infralittoral areas, boat anchoring in seagrass meadows and tropical reefs, or SCUBA-diving. In this paper we review the available literature world-wide on the effects of human recreational activities in marine communities. The objective is to address the extent of these impacts and to highlight the gaps of knowledge to be filled in order to optimize decision making on research, monitoring, and management of Mediterranean MPAs. A specific plan for managing tourism use in each Mediterranean MPA should be designated. These strategies should be implemented through education, training, and changes in legislation and policy.

human impact, marine protected area, anchoring, SCUBA-diving, trampling, recreation, Mediterranean Sea

Miller, E. F. 2007. Post-Impingement Survival and Inferred Maximum Thermal Tolerances for Common Nearshore Marine Fish Species of Southern California. Bulletin, Southern California Academy of Sciences. 106:193-207.

The effectiveness of a pilot post-impingement fish return program was studied at Los Angeles Department of Water and Power's Scattergood Generating Station during six heat treatments from February 2005 to August 2006. Species-specific total percent survival was computed for all individuals impinged, with an overall survival of 0.4% across all species impinged during monitored heat treatments, ranging from 30.2% for Paralabrax clathratus to 0.0% for Seriphus politus. Species-specific critical thermal maxima was inferred from surveys of the abundances returned by San Onofre Nuclear Generating Station's highly effective and unique Fish Return System during heat treatments from 2000-2005. Abundant species such as queenfish exhibited low thermal thresholds (15-20°C), while spotfin croaker and barred sand bass became stressed at higher temperatures (25-30°C).

Mitarai, S., D. A. Siegel and K. B. Winters. 2008. A numerical study of stochastic larval settlement in the California Current system. Journal of Marine Systems. 69:295-309.

Key to the predictive understanding of many nearshore marine ecosystems is the transport of larvae by ocean circulation processes. Many species release thousands to billions of larvae to develop in pelagic waters, but only a few lucky ones successfully settle to suitable habitat and recruit to adult life stages. Methodologies for predicting the larval dispersal are still primitive, and simple diffusive analyses are still used for many important applications. In this study, we investigate mechanisms of larval dispersal using idealized simulations of time-evolving coastal circulations in the California Current system with Lagrangian particles as models for planktonic larvae. Connectivity matrices, which describe the source-to-destination relationships for larval dispersal for a given larval development time course, are used to diagnose the time-space dynamics of larval settlement. The resulting connectivity matrices are shown to be a function of several important time scales, such as the planktonic larval duration, the frequency and duration of larval release events and inherent time scales for the coastal circulations. Many important fishery management applications require knowledge of fish stocks on a year-to-year or generation-to-generation basis. For these short time scales (typically less than 1 year), larval dispersal is generally far from a simple diffusive process and the consideration of the stochastic and episodic nature of larval dispersal is required. This work provides new insights into the spatial-temporal dynamics of nearshore fish stocks.

Larval dispersal; Dispersal kernel; Coastal oceanography; California Current; Marine resource management

Moffitt, E. A., L. W. Botsford, D. M. Kaplan and M. R. O'Farrell. 2009. Marine reserve networks for species that move within a home range. Ecological Applications. 19:1835-1847.

Marine reserves are expected to benefit a wide range of species, but most models used to evaluate their effects assume that adults are sedentary, thereby potentially overestimating population persistence. Many nearshore marine organisms move within a home range as adults, and there is a need to understand the effects of this type of movement on reserve performance. We incorporated movement within a home range into a spatially explicit marine reserve model in order to assess the combined effects of adult and larval movement on persistence and yield in a general, strategic framework. We describe how the capacity of a population to persist decreased with increasing home range size in a manner that depended on whether the sedentary case was maintained by self persistence or network persistence. Self persistence declined gradually with increasing home range and larval dispersal distance, while network persistence decreased sharply to 0 above a threshold home range and was less dependent on larval dispersal distance. The maximum home range size protected by a reserve network increased with the fraction of coastline in reserves and decreasing exploitation rates outside reserves. Spillover due to movement within a home range contributed to yield moderately under certain conditions, although yield contributions were generally not as large as those from spillover due to larval dispersal. Our results indicate that, for species exhibiting home range behavior, persistence in a network of marine reserves may be more predictable than previously anticipated from models based solely on larval dispersal, in part due to better knowledge of home range sizes. Including movement within a home range can change persistence results significantly from those assuming that adults are sedentary; hence it is an important consideration in reserve design.

adult movement; dispersal per recruit; fisheries; home range; marine protected areas; marine reserves; spillover; sustainability; yield

Molloy, P. P., I. B. McLean and I. M. Cote. 2009. Effects of marine reserve age on fish populations: a global meta-analysis. Journal of Applied Ecology. 46:743-751.

  1. Marine reserves are widely used for conservation and fisheries management. However, there is debate surrounding the speed of population recovery inside reserves and how recovery differs among species. Here, we determine how reserve effectiveness in enhancing fish density changes with reserve age. We also examine how the effects of protection vary between fished and non-fished species and among species of different body sizes, which we use as a proxy for life history and ecology.
  2. We meta-analysed over 1000 ratios of fish densities (inside : outside reserves) taken from reserves of 1-26 years old from around the world.
  3. Overall, older reserves were more effective than younger reserves, with fish densities increasing within reserves by ~5% per annum relative to unprotected areas. Reserves older than 15 years consistently harboured more fish compared with unprotected areas; younger reserves were less reliably effective.
  4. Large, fished species responded strongly and positively to protection in old (>15 years) and, unexpectedly, in new and young (<10 years) reserves. Small, fished species and non-fished species of all sizes showed weaker responses to protection that did not vary predictably with reserve age.
  5. We expected large fish to respond more slowly to protection than smaller species. We also expected small species to decline after large fish had recovered (i.e. trophic cascades). Neither prediction was supported.
  6. Synthesis and applications. Our meta-analyses demonstrate that, globally, old reserves are more effective than young reserves at increasing fish densities. Our results imply that reserves should be maintained for up to 15 years following establishment, even if they initially appear ineffective. If protection is maintained for long enough, fish densitieswithin reserves will recover and such benefits will be particularly pronounced for large, locally fished species.

fisheries; life-history effects; marine conservation; marine protected areas; marine sanctuary; meta-analysis; overfishing; population recovery; protection duration; trophic cascade

Molloy, P. P., J. D. Reynolds, M. J. G. Gage, I. Mosqueira and I. M. Cote. 2008. Links between sex change and fish densities in marine protected areas. Biological Conservation. 141:187-197.

Sex change is widespread among marine fishes, including many species that are fished heavily, and is thought to be of conservation concern under some circumstances. As such, an important question in conservation is whether the implementation of marine protected areas (MPAs), which is a commonly used marine conservation tool, works as effectively for sex-changers as for non-sex-changers. To address this issue, we used meta-analyses of the ratio of fish abundances inside vs. outside MPAs to determine whether sex change affects the extent to which fish densities respond to protection. When all data were considered, there were similar responses to protection irrespective of reproductive mode. However, when analyses were restricted to older reserves (at least 10 years' protection), female-first sex-changers consistently benefited from protection. Non-sex-changers and male-first sex-changers showed more variable responses to protection and, as a result, there were no significant differences between fish with different reproductive modes in their overall response to protection. The same results were observed when the effects of fisheries status (targeted vs. not targeted) were controlled. Our results support the use of MPAs as important components of conservation and demonstrate that old reserves are most consistently beneficial to female-first sex-changing species. Finally, our results highlight the fact that some effects of protection are only detectable after several generations.

Body size; Exploitation; Fishing; Grouper; Hermaphroditism; Meta-analysis; Parrotfish

Monaco, M. E., A. M. Friedlander, C. Caldow, J.D. Christensen. (2007). Characterising reef fish populations and habitats within and outside the US Virgin Islands Coral Reef National Monument: a lesson in marine protected area design. Fisheries Management and Ecology 14: 33-40.

Marine protected areas are an important tool for management of marine ecosystems. Despite their utility, ecological design criteria are often not considered or feasible to implement when establishing protected areas. In 2001, the Virgin Islands Coral Reef National Monument (VICRNM) in St John, US Virgin Islands was established by Executive Order. The VICRNM prohibits almost all extractive uses. Surveys of habitat and fishes inside and outside of the VICRNM were conducted in 2002–2004. Areas outside the VICRNM had significantly more hard corals, greater habitat complexity, and greater richness, abundance and biomass of reef fishes than areas within the VICRNM. The administrative process used to delineate the boundaries of the VICRNM did not include a robust ecological characterisation of the area. Because of reduced habitat complexity within the VICRNM, the enhancement of the marine ecosystem may not be fully realised or increases in economically important reef fishes may take longer to detect.

conservation, coral reefs, marine protected areas, marine reserves, reef fish, US Virgin Islands<

Moore, S. L. and M. J. Allen. 2000. Distribution of Anthropogenic and Natural Debris on the Mainland Shelf of the Southern California Bight. Marine Pollution Bulletin. 40:83-88.

Various studies have been conducted to quantify debris found along beaches; however, little information has been compiled about debris found on the seafoor. This study describes the distribution, types, and amounts of marine debris found in the Southern California Bight (SCB) in July and August of 1994. Anthropogenic debris was most common in the central region, on the outer shelf, and in areas near publicly owned treatment works (POTWs). Fishing gear was the most common type of anthropogenic debris in the central region and in the outer shelf zone, whereas glass bottles and plastic were most common in POTW areas. Natural debris was more common close to shore in the inner shelf zone than anthropogenic debris. The deeper distribution of anthropogenic debris relative to natural debris, as well as the types of debris, suggest that the primary source of anthropogenic debris is marine vessel and fishing activity.

debris; Southern California Bight; continental shelves; fishing gear; baseline studies; pollution monitoring

Morgan, L. E., L.W. Botsford, C.J. Lundquist, J.F. Quinn. 1999. The potential of no-take reserves to sustain the red sea urchin (Strongylocentrotus franciscanus) fishery in northern California. Bulletin of Tohoku National Fisheries Research Institute, Special Issue 62: 83-94.

The red sea urchin, Strongylocentrotus franciscanus, in northern California has been heavily exploited in recent years. Recent decline in fishery landings has prompted exploration of alternatives to traditional management. No-take reserves are one management alternative to protecting spawning biomass in the face of uncertainties related to recruitment. Here we review ongoing work to estimate recruitment, growth and mortality rates and discuss their relevance to harvest refugia in northern California. Recruitment is irregular, episodic and consistent with mesoscale circulation patterns. Growth and mortality rate estimates at unharvested locations, indicate red sea urchins are slow growing and long lived. Analysis of egg per recruit curves and present estimates of fishing mortality rate suggest present harvest rates are unsustainable. We have shown that metapopulation dynamics of red sea urchins in northern California are dominated by temporal and spatial variability in recruitment which is subject to patterns of coastal circulation, rather than local site dynamics. Size distributions and densities collected in areas closed to sea urchin harvest suggest these areas are successfully protecting spawning biomass, but the limited coastwide area encompassed by no fishing zones restricts their potentially positive impact on recruitment. Implementation of no take reserves would protect spawning biomass in the face of intense harvest pressure.

Morgan, S. G. and J. R. Anastasia. 2008. Behavioral tradeoff in estuarine larvae favors seaward migration over minimizing visibility to predators. Proceedings of the National Academy of Sciences. 105:222-227.

The ability of microscopic larvae to control their fate and replenish populations in dynamic marine environments has been a longrunning topic of debate of central importance to understanding the ecology and evolution of life in the sea and managing resources in a changing global environment. After decades of research documenting behaviors that keep larvae close to natal populations, it is becoming apparent that larval behaviors in a broader spectrum of species promote long-distance migrations to offshore nursery grounds. Larvae must exert considerable control over their movements. We now show that larval emigration from estuaries is favored even over minimizing visibility to predators. An endogenous tidal vertical migration that would expedite seaward migration of Uca pugilator larvae was maintained experimentally across two tidal regimes. The periodicity of the rhythm doubled to match the local tidal regime, but larvae ascended to the surface during the daytime rather than at night. This process would conserve larval emigration but increase the visibility to predators across part of the species range. The periodicity of tidal vertical migration by Sesarma cinereum larvae failed to double and was inappropriately timed relative to both environmental cycles in the absence of a diel cycle. The timing system regulating tidally timed behaviors in these two species of crabs evidently differed. Phenotypic plasticity can conserve larval transport of both species when tidal and diel cycles are present. It may be widespread in the sea where diverse habitats are encountered across extensive species ranges.

dispersal; larval transport; vertical migration; phenotypic plasticity; species ranges

Mosquera, I., I.M. Cote, S. Jennings, and J.D. Reynolds. 2000. Conservation benefits of marine reserves for fish populations. Animal Conservation 4: 321-332.

We synthesize the results of empirical studies of marine reserves to assess the potential benefits of protection for fish populations. Our meta-analyses demonstrate that the overall abundance of fishes inside reserves is, on average, 3.7 times higher than outside reserve boundaries. This enhancement is mainly a result of a significant increase in abundance of species that are the target of fisheries. Non-target species are equally abundant inside and outside reserves. Large-bodied species also respond more to protection, irrespective of their fishery status. Species within genera show great heterogeneity in their response to protection despite similarities in their life histories. Our study confirms that marine reserves benefit fish populations and highlights the need for monitoring prior to reserve establishment to provide more accurate, habitat-controlled studies of the effects of marine reserves on fish populations.

Murray, S. N., T. G. Denis, J. S. Kido and J. R. Smith. 1999. Human visitation and the frequency and potential effects of collecting on rocky intertidal populations in Southern California marine reserves. CalCOFI Report. 40:100-106.

Humans intensely use southern California rocky shores for recreational activities such as fishing, exploration, walking, enjoyment of the out-of-doors, and educational field trips. People also collect intertidal organisms for consumption, fish bait, home aquariums, and other purposes. In Orange County, visitors concentrate their activities on a few rocky headlands and reefs. Many of these shores have been designated as California Marine Life Refuges (CMLRs) or State Ecological Reserves (SERs), where the removal of most intertidal organisms, except for scientific purposes, has been unlawful for 30 years. In a yearlong study of eight Orange County shores, unlawful collecting of organisms was often observed. In addition, lifeguards have frequently observed unlawful collecting on these and other shores. The CMLR or SER designation did not deter collecting. Mussels, trochid snails, limpets, urchins, and octopuses were the most commonly collected organisms, primarily for food or fish bait. Several of the gastropod species targeted by human collectors had low population densities and population structures dominated by smaller and less fecund individuals, characteristics that often occur in populations exploited by humans. Most collected invertebrates were broadcast spawners that require high densities of fertile individuals to optimize reproduction. The cascading effects of collecting on community structure and the reproductive success of exploited populations are unknown. Except for state park rangers at one site, no state enforcement personnel were seen during 768 hours of low-tide observations throughout the year. Without effective enforcement, adequate signage, and educational programs to increase public awareness, CMLRs and SERs are not protecting rocky intertidal populations on heavily visited southern California shores. Improved management practices are needed if CMLRs and SERs are to protect rocky intertidal populations and to serve as benchmark sites where changes in populations due to regional climatic events or chronic human disturbances can be measured and evaluated in the absence of exploitation.

Murray, S.N., R.F. Ambrose, J.A. Bohnsack, L.W. Botsford, M.H. Carr, G.E. Davis, P.K. Dayton, D. Gotshall, D.R. Gunderson, M.A. Hixon, J. Lubchenco, M. Mangel, A. MacCall, D.A. McArdle, J.C. Ogden, J. Roughgarden, R.M. Starr, M.J. Tegner, M.M. Yoklavich 1999. No-take Reserve Networks: Sustaining Fishery Populations and Marine Ecosystems. Fisheries 24(11):11-25. (Summarized by Irene Tetreault Beers)

No-take reserve networks can complement existing management practices, improve efforts to interrupt declining trends in fishery populations, and help improve marine ecosystems for future generations. Ecosystems are now suffering decreased biodiversity and habitat degradation, and species' populations are declining in size and number. The United States is not effectively protecting marine resources due to the practice of open access and lack of political will. Improved management is required to sustain fisheries and protect ecosystems. Existing management practices are not sufficient to protect the resource. Most fisheries are still managed on a single-species basis even though multiple species are caught in almost all of them. Existing management models require information that is seldom possible to ascertain. Thus ensuring sustainable fisheries is very difficult using traditional management techniques and a precautionary approach is required.

West Coast groundfish stocks are now jeopardized. They were intensively fished by foreign boats in the 1960's and 1970's and then domestically in the 1980's and 1990's. Rockfish (Sebastes) are particularly vulnerable due to their slow growth, late maturity, and infrequent successful reproduction. In particular, Pacific ocean perch (Sebastes alutus), bocaccio (S. paucispinnis), canary (S. pinniger) and widow rockfish (S. entomelas) populations are dangerously depleted, as well as others. Five California abalone (Haliotis) stocks have been serially depleted and this fishery has collapsed. In 1992 sea urchins were California's most valuable marine fishery, but it is now harvested at full capacity. Increasing effort in California's commercial live-fish fishery fishery may deplete many shallow-water fishes. California sheephead (Semicossyphus pulcher), a principal live-fish target, graze sea urchins and an increase in unfished sea urchins could destroy kelp forest communities.

There are presently 0.2% of California's state waters in no-take reserves. Multiple marine reserves are needed because many marine populations depend on distant sources of larvae transported on ocean currents. A reserve network can: 1) help recover fishery populations; 2) eliminate mortality of non-targeted species within protected areas due to bycatch, discards, and ghost fishing; 3) protect reserve habitats from damage by fishing gear; and 4) increase the probability that rare and vulnerable habitats, species and communities persist. Reserve networks can also increase scientific understanding of ecosystems and distinguish between the effects of fishing and natural variability. They can also increase non-consumptive use opportunities that have substantial social and economic value. No-take marine reserves have repeatedly increased abundance, average size and spawning biomass of target species in the reserve. They may enhance fished populations through increased larval output, exporting species to fishing grounds and protecting species from genetic changes and altered sex ratios. Networks can protect against stock collapse as a bet-hedging strategy, act as seed stock, decrease annual catch variability, allow for scientific study, and protect habitat.

For an optimal network design: 1) clearly identify goals, objectives and expectations; 2) represent a wide variety of environmental conditions; 3) replicate reserves within each biogeographic region; 4) accommodate adaptive management; and 5) allow sufficient size to be self-sustaining. For example, in California, a network should include nearshore coast, offshore islands, edges of continental slope, submarine canyons and offshore pinnacles. It should also should include major upwelling cells that occur at approximately every 100 km (62 miles) to aid larval movement for fish and invertebrates. Pristine or lightly-used areas are excellent candidates for reserves, but high-use areas adjacent to urban areas may show stronger responses to protection as long as they are also protected from other sources of human disturbance. Multiple reserves, or replication, reduces risk that populations or habitat are destroyed by a catastrophe, assists successful reproduction and is critical for rigorous scientific testing and improved management. Initially, reserves should be based on the best available science and then studied. Current science supports significantly expanding the amount of marine habitat presently in no-take reserves. Proper evaluation is needed, along with adaptive management, that is, adjusting boundaries and regulations based on research results. Socioeconomic costs must be weighed against the expected benefits of creating reserves. Phasing in reserves may help reduce impacts to users. Local and scientific knowledge must be coordinated through local, state and federal agencies. In addition enforcement and compliance are critical.

Murawski, S.A., R. Brown, H-L Lai, P.J. Rago, L. Hendrickson. 2000. Large-scale closed areas as a fishery-management tool in temperate marine systems: The Georges Bank experience. Bulletin of Marine Science 66(3).

Seasonal closed areas have been an element of fishery management in New England waters since 1970 but before 1994 had limited impact on the conservation of groundfish stocks for which they were designed. Beginning in December of 1994, three large areas of historic importance to groundfish spawning and juvenile production on Georges Bank and in Southern New England, totaling 17,000 km super(2), were closed year-round to any gears capable of retaining groundfish (trawls, scallop dredges, gill nets, hook fishing). In the ensuing five years, the closed areas contributed significantly to reduced fishing mortality of depleted groundfish stocks. Placements of the closed areas afforded the greatest year-round protection to the shallow-sedentary assemblage of fishes (primarily flounders, skates, and miscellaneous others) and bivalve molluscs. Although the closures afforded less year-round protection to migratory age groups of Atlantic cod, Gadus morhua, and haddock, Melanogrammus aeglefinus, additional new regulations in open areas and in the Canadian portions of Georges Bank also contributed to the observed reductions in stock-wide fishing mortality rates. The areas were closed to dredge gear designed for sea scallops, Placopecten magellanicus, because of groundfish by-catch (particularly of flounders). Scallop biomass increased 14-fold within the closed areas during 1994-1998. In July 1998, total and harvestable scallop biomasses were 9 and 14 times denser, respectively, in closed than in adjacent open areas. A portion of the closed areas was designated a "habitat area of particular concern" on the basis of patterns of occurrence of juvenile ground-fish in gravel/cobble sediment types. Managers reopened portions of one closed area to sea-scallop dredging in 1999, but restrictions on gear and areas fished were used to minimize groundfish by-catch and impact on juvenile cod and haddock on gravel substrates. Results from these reopenings have encouraged managers to contemplate a formal `area rotation' scheme for scallops intended to improve yield per recruit. Closures of large portions of Georges Bank have proved to be an important element leading to more effective conservation of numerous resource and nonresource species, despite selection of the closed areas on the basis of seasonal spawning grounds of haddock and the distribution of yellowtail flounder, Limanda ferrugineus, in southern New England. In the future, factors other than fishing mortality reduction, including optimal placement to enhance larval production and to protect nursery areas and spawning concentrations, may well influence the selection of closed-area boundaries.

Narvaez, D. A., S. A. Navarrete, J. L. Largier and C. A. Vargas. 2006. Onshore advection of warm water, larval invertebrate settlement, and relaxation of upwelling off central Chile. Marine Ecology Progress Series. 309:150-173.

Observations from several places around the world suggest that periods of relaxation of winds that drive upwelling favor the onshore transport of larvae entrained in shoreward movement of warm surface waters. However, the generality of this process has not yet been appropriately evaluated. We examined the frequency, intensity, spatial extent, and inter-annual variability of sea surface temperature fluctuations associated with the relaxation of equator-ward winds and their influence on invertebrate settlement in central Chile (33° 30' S, 71° 40' W). Our results showed that there were marked differences in the intensity and structure of temperature increases following the relaxation of upwelling favorable winds. While most temperature increases were small (0.5 to 1°C) and preserved the stratification of the water column, large 'warming events' (>3°C) led to a breakdown of stratification for periods of 3 to 9 d at least twice during each spring-summer season. These large warming events occurred in association with downwelling-favorable (northerly) winds, and their formation might have required certain conditions in terms of mesoscale eddy features and local topography. Settlement of invertebrates occurred during these events as well at other times, and was not quantitatively correlated with relaxation or downwelling conditions. However, during specific large warming events, we observed significant synchrony in the settlement of several marine invertebrate taxa (e.g. decapods, gastropods, polychaetes, mussels, and sea urchins). Thus, at this site in central Chile and during our period of study, relaxation events did not dominate settlement, and it appeared that the upwelling-relaxation model did not adequately represent the larval transport mechanism for any taxa examined. However, large warming events (which produced synchrony in the settlement of several different taxa) could be important in that they may result in uniform settlement along the shore and deliver larvae from distant origins, increasing long-distance demographic and genetic connectivity. Thus, these infrequent events are likely to be a critical factor in settlement distribution along the shore.

Large warming events; Onshore advection; Daily settlement; Upwelling; Downwelling; Relaxation; Larval invertebrates; Central Chile

National Fisheries Conservation Center (NFCC). Integrating Marine Reserve Science and Fisheries Management. 2004. NFCC Consensus Statement, June 7-9, 2004, Long Beach, California.

Marine reserves should be considered in the broader context of the development of ecosystem-based management in the U.S. From that perspective, marine reserves have clear application for meeting objectives for ecosystem conservation and protection of marine biodiversity in addition to whatever benefits they may have for achieving fishery management objectives. Furthermore, marine reserves are a category of area management options-including less restrictive and less permanent alternatives-that may be used in order to achieve ecosystem- or species-based management objectives.

With regard to fishery effects, many studies of marine reserves and other area closures, most of which are from lower latitudes, have now shown that fishery target species have increased in abundance and expanded age structure within the closed area in a preponderance of cases (the so-called "reserve effect."). This is particularly the case where the resource species are significantly overfished. Evidence for effects outside closed areas, either by movement of adults across the reserve boundaries ("spillover") or larval "export" is more limited and effects on stocks within larger regions can only be deduced by models at this point. This is because of the limited size of existing reserves and inherent difficulties in measuring and interpreting such broader effects. In general, knowledge is sufficient to proceed with the design and evaluation of marine reserves and other marine protected areas and their incorporation into regional ecosystem-based management. More sophisticated modeling and analysis is required for better understanding of spatial movement rates, export of reproductive products, and adaptations by fishers.

Marine reserves clearly offer some advantages for simultaneously incorporating habitat protection and maintenance of ecosystem structure and function within the protected area. They may offer some advantages for multi-species management and as a hedge against environmental surprise or management failure.

Marine reserves are most likely to be an effective management tool for relatively sedentary species with broad larval dispersal, which are recruitment limited, and for mobile species with high site fidelity. They may also be effective for protecting rare habitats vulnerable to human disruption or in protecting aggregations of animals (e.g., when spawning), when exploited populations have been severely depleted, or where bycatch is high. Closed areas may also be useful in achieving broad demographic representation in spawning populations if large animals have limited movement potential relative to reserve boundaries, and when they can maintain populations of highly fecund, older females with strong reproductive potential. They may be more feasible to implement either when reduced yields have already restricted fishing activities and other management measures have been ineffective or when they address special needs within otherwise productive regions.

Marine reserves and other protected areas should be integrated with existing and emerging management measures as part of a coherent ecosystem-based approach to management of commercial and recreational fisheries and should not be simply layered over existing regulations. Careful consideration of the effects on allocation of resources among users, displacement of fishing activity, the requirements for surveys and stock assessment, and the costs of monitoring and enforcement should be made in considering protected area options and design.

The Panel found it difficult to limit its considerations to marine reserves as strictly defined, i.e. areas permanently protected from all extractive activities. We found that management actions need to be openly evaluated against stated goals and where goals are not being met changes in management must at least be considered. The design requirements for marine reserves depend heavily on the environmental context and specific management goals, including the overriding goal of sustainability and high yields of economically important species. Robust experimental design will be critical in order to determine the effects of displaced fishing pressures and enhancement effects on populations outside of reserves in before-after-control-impact assessments.

We have been hampered in evaluating the use of marine reserves as a tool for fishery management by the lack of experiments explicitly designed to address reserve effects on fisheries. These explicit experiments are urgently needed. There are numerous uncertainties associated with our understanding both of important biological and socioeconomic processes and with monitoring, analysis, prediction, and implementation. Some important uncertainties for marine reserves include the degree of effective dispersion and reproductive seeding and the ability to resolve spatial and temporal interactions in monitoring and modeling.

Further study is required on several key issues if closed areas are to assume a more important role in ecosystem approaches to fisheries management and biodiversity protection. These include high quality, synthetic bottom mapping with which to define vulnerable habitats that closed areas might best protect; study of dispersal rates; synthesis of effects of closures in northern temperate and boreal systems.

Many authors have speculated that marine reserves offer more precaution against management and scientific uncertainty than traditional measures. At this point, this is an assertion, and no studies using common definitions and metrics of precaution have been conducted. Given the importance of this issue, there is a need to conduct such work, applying biology and social science, particularly as it relates to findings from existing marine closures.

Neigel, J.E. 2003. Species-Area Relationships and Marine Conservation. Ecological Applications 13(1) Supplement: S138-S145.

The species-area relationship (SPAR) was the central paradigm for the emerging science of reserve design in the 1970s and early 1980s. The apparent consistency of the SPAR for natural areas suggested that it could be used to predict the number of species that would be maintained within the isolated confines of a nature reserve. This proposed use of the SPAR led to heated debates about how best to partition space among reserves. However, by the end of the 1980s, the SPAR was no longer a central issue in reserve design. There was too much uncertainty about the underlying causes of the SPAR to trust that it would hold for reserves. The SPAR was also inappropriate for the design of single-species reserves and thus did not answer the traditional needs of wildlife managers. Ecologists subsequently focused their reserve-design efforts on the management of individual populations to reduce the probability of extinction and the loss of genetic variation. Nevertheless, because the SPAR does not require detailed knowledge of the requirements of individual species, it is still used to estimate local species richness and to predict the effects of habitat loss and fragmentation on biodiversity. These applications of the SPAR may be especially useful in the design of marine reserves, which often differ in purpose from conventional terrestrial reserves and may require fundamentally different approaches.

Nowlis, J. S. and C. M. Roberts. 1999. Fisheries benefits and optimal design of marine reserves. Fishery Bulletin. 97:

We used fishery population models to assess the potential for marine fishery reserves, areas permanently closed to fishing, to enhance long-term fishery yields. Our models included detailed life history data. They also included the key assumptions that adults did not cross reserve boundaries and that larvae mixed thoroughly across the boundary but were retained sufficiently to produce a stock-recruitment relationship for the management area. We analyzed the results of these models to determine how reserve size, fishing mortality, and life history traits, particularly population growth potential, affected the fisheries benefits from reserves. We predict that reserves will enhance catches from any overfished population that meets our assumptions, particularly heavily overfished populations with low population growth potential. We further predict that reserves can enhance catches when they make up 40% or more of fisheries management areas, significantly higher proportions than are typical of existing reserve systems. Finally, we predict that reserves in systems that meet our assumptions will reduce annual catch variation in surrounding fishing grounds. The fisheries benefits and optimal design of marine reserves in any situation depended on the life history of the species of interest as well as its rate of fishing mortality. However, the generality of our results across a range of species suggest that marine reserves are a viable fisheries management alternative.

O'Farrell, M. R. and M. M. Yoklavich. (2009). Assessment of habitat and predator effects on dwarf rockfishes (Sebastes spp.) using multi model inference. Environ Biol Fish 85: 239-250.

Habitat associations and the effect of predators on dwarf rockfishes (Sebastes spp.) were investigated in two large marine protected areas (MPAs) off southern California. Using data from submersible surveys, the occurrence and abundance of dwarf rockfishes were modeled using substrata types and the biomass of predators as predictor variables. The occurrence and abundance of dwarf rockfishes generally were positively associated with rock, boulder, and cobble substrata. The association between predators and occurrence of dwarf rockfishes differed substantially between species. Predator density and biomass levels were much lower in the southern California MPAs than in a de facto MPA off central California. Better inference about predator effects on dwarf rockfishes will be possible if the predator biomass and densities of southern California MPAs increase to that observed in the de facto MPA.

Habitat association, Community structure, Akaike Information Criterion, Model averaging

Osmond, M., S. Airame, M. Caldwell, J. Day. (2010). Lessons for marine conservation planning: A comparison of three marine protected area planning processes. Ocean & Coastal Management: 1-11.

Various approaches have been used to establish marine protected areas (MPAs) in different countries. In this paper we compare and review three processes to establish MPAs within the United States and Australia. These two countries share many similarities in their cultures, but their approaches to managing marine resources differ considerably. Each of these efforts to establish or review MPAs was motivated by concern about declines of targeted marine species or habitats. However, the government actions varied because of differences in governance, planning process including public input, and the role of science. Comparing these processes highlights effective approaches for protecting marine ecosystems and gaining public support.

marine protected areas, Australia, USA, planning process

Paddack, M.J. and J.A. Estes. 2000. Kelp forest fish populations in marine reserves and adjacent exploited areas in Central California. Ecological Applications 10(3):855-870. [Adapted from summary by Fish Briefs (]

The undersea kelp forests off the West Coast are known for their productivity and biodiversity. They also serve as important habitat for commercially-sought rockfish species. While once abundant, overfishing and possibly long-term change in oceanographic conditions have placed many rockfish stocks in jeopardy of overexploitation. The purpose of the study was to assess the effect of marine reserves on populations of exploited fish species in central California. This work was a comparative study of the population density and size distribution of ten species of kelp-forest fishes in three marine reserves and adjacent areas where fishing occurs in central California. The reserves studied were Hopkins Marine Life Refuge, Point Lobos Ecological Reserve and Big Creek Marine Resources Protection Act Ecological Reserve.

The study compared kelp habitats in three near-shore marine reserves to similar near-shore habitats in areas open to fishing. To make the comparison, scientists studied ten species of rockfish and analyzed: (1) the number of fish; (2) the quality of the habitat; (3) the size of fish; and (4) total fish biomass and reproductive potential. The study found that the average length of rockfish was greater in two of the three marine reserve sites, as was the proportion of larger fish. This demonstrates that current levels of fishing pressure affect rockfish populations in fished areas by selectively removing adult fish from the population. Selective removal of larger, adult fish can have a negative effect on the health of a fish population because the reproductive potential of larger, older rockfish is dramatically higher than smaller, younger rockfish.

While the study did find a significant difference in age structure between rockfish sampled in the two sets of areas, it was unable to show significant differences in the number of fish and habitat quality between reserve and non-reserve sites. Possible explanations for these results are: (1) the lack of the necessary baseline biological data for existing marine reserves and (2) the inadequacy of existing marine reserves as a tool to obtain data necessary to properly make these extremely important large-scale comparisons. Although there are 103 marine protected areas along the California coast, only 11 are designated "no take" zones -- areas where fishing and other extractive activities are prohibited. Existing reserves are very small, rarely larger than one square mile.

In addition to the lack of baseline data, numerous factors affected the study's results. Statistical analysis was very difficult because the marine protected areas used as control areas (without commercial fishing) were small and few, with high variation among sample units. Further, as most of the closed areas were small and only represented a minute percentage of the overall range of rockfish species, these areas were prone to external effects of fishing, including overfishing, as they likely rely on larvae from external areas for seeding. Also, as these areas have little enforcement and are near coastal areas, poaching is common. Therefore, illegal fishing has likely affected the ability of these areas to act as "control" sites for comparison studies.

Palumbi, S. R., K. L. McLeod, D. Grunbaum. (2008). Ecosystems in Action: Lessons from Marine Ecology about Recovery, Resistance, and Reversibility. BioScience 58(1): 33-42.

The study of ecosystems in action, by measuring ecosystem recovery from disturbance, resistance to alterations, and the reversibility of ecosystem changes, highlights features of natural communities that contribute to resilience. Examples from marine intertidal and subtidal communities document the importance of species redundancy and complementarily in resistance and recovery, and they also show why recovery potential and resistance can differ from place to place within the same ecosystem. Whether a change is considered reversible may depend on the timescale of interest, and on whether fundamental new ecological processes have taken hold after a disturbance. By focusing on recovery, resistance, and reversibility as key components of resilience, marine ecologists have provided a much-needed empirical database about the response of the living world to human-mediated change.

disturbance, sustainability, resilience, kelp forest, coral reef

Palumbi, S. R., S. D. Gaines, H. Leslie, R. Warner. (2003). New Wave: High-Tech Tools to Help Marine Reserve Research. Frontiers in Ecology and the Environment 1(2): 73-79.

Marine reserves are an emerging management tool, and can serve as examples of the practical application of basic marine ecology. Although some aspects of reserve science are well known, new information is badly needed in at least two major areas: the impact that reserves have on their surrounding ecosystems, and how we can use complex ecological and environmental data to inform management decisions. We describe the application of four new tools being used in oceanography and marine ecology to help design ocean reserves. Ocean sensing charts the dynamics of ocean environments, allowing us to see physical connections between protected and non-protected areas. The indirect monitoring of species dispersal through chemical tags and genetic comparisons can help us to map population movements and measure the spread of species. Computer-based mapping programs enable us to use GIS databases in management decisions, and give multiple stakeholders access to powerful decision-making tools. Together, these methods describe ecosystem patterns over spatial and temporal scales that are directly relevant to conservation and ecosystem management.

GIS, mapping tools, marine reserve

Palumbi, S.R. 2003. Population Genetics, Demographic Connectivity, and the Design of Marine Reserves. Ecological Applications 13(1) Supplement: S146-S158.

Genetic analyses of marine population structure often find only slight geographic differentiation in species with high dispersal potential. Interpreting the significance of this slight genetic signal has been difficult because even mild genetic structure implies very limited demographic exchange between populations, but slight differentiation could also be due to sampling error. Examination of genetic isolation by distance, in which close populations are more similar than distant ones, has the potential to increase confidence in the significance of slight genetic differentiation. Simulations of one-dimensional stepping stone populations with particular larval dispersal regimes shows that isolation by distance is most obvious when comparing populations separated by 2-5 times the mean larval dispersal distance. Available data on fish and invertebrates can be calibrated with this simulation approach and suggest mean dispersal distances of 25-150 km.

Design of marine reserve systems requires an understanding of larval transport in and out of reserves, whether reserves will be self-seeding, whether they will accumulate recruits from surrounding exploited areas, and whether reserve networks can exchange recruits. Direct measurements of mean larval dispersal are needed to understand connectivity in a reserve system, but such measurements are extremely difficult. Genetic patterns of isolation by distance have the potential to add to direct measurement of larval dispersal distance and can help set the appropriate geographic scales on which marine reserve systems will function well.

Palumbi, S.R. 2004. Why Mothers Matter. Nature 430: 621-622

Fish population growth depends on older mothers, which in some species produce more and 'better' offspring than younger fish. When fisheries remove the most productive females, the whole population suffers.

Pande, A., A. B. MacDiarmid, P. J. Smith, R. J. Davidson, R. G. Cole, D. Freeman, S. Kelly and J. P. Gardner. 2008. Marine reserves increase the abundance and size of blue cod and rock lobster. Marine Ecology Progress Series. 366:147-158.

Size and abundance data were compiled and collated for blue cod Parapercis colias and rock lobster Jasus edwardsii from New Zealand marine reserve (MR) studies for a meta-analysis to test the null hypotheses that reserve status does not affect the size or abundance of either species. Calculation of meta-analysis effect sizes revealed that significant differences in effect size existed among studies, meaning that the biological response to MR status of both species in terms of their changes in size and/or abundance differed significantly among the MRs. Analysis revealed that blue cod were bigger inside compared with outside MRs in 9 of 10 studies and were more abundant inside MRs in 8 of 11 studies, and that rock lobster were bigger inside the MRs in 12 of 13 studies and more abundant inside the MRs in 11 of 14 studies. These findings indicate that MR protection can result in more and bigger individuals soon after the establishment of the MR (mean of 6.5 yr for blue cod, 8.5 yr for rock lobster) despite small sample sizes of studies (a=10 for blue cod, a=14 for rock lobster). Focused comparison tests did not reveal any relationship between rock lobster or blue cod size or abundance and either age or area of MRs. Our results demonstrate that no-take MRs are valuable conservation tools for species such as blue cod and rock lobster (and probably also for other exploited species with similar life history characteristics and habitat requirements) and that statistically detectable conservation benefits are apparent after only a few years of protection.

Meta-analysis; Focused comparison tests; Marine reserves; Marine conservation; Blue cod; Rock lobster; Mean size and mean abundance; New Zealand

Parnell, P. E., P. K. Dayton, C. E. Lennert-Cody, L. L. Rasmussen and J. J. Leichter. 2006. Marine reserve design: optimal size, habitats, species affinities, diversity, and ocean microclimate. Ecological Applications. 16:945-962.

The design of marine reserves is complex and fraught with uncertainty. However, protection of critical habitat is of paramount importance for reserve design. We present a case study as an example of a reserve design based on fine-scale habitats, the affinities of exploited species to these habitats, adult mobility, and the physical forcing affecting the dynamics of the habitats. These factors and their interaction are integrated in an algorithm that determines the optimal size and location of a marine reserve for a set of 20 exploited species within five different habitats inside a large kelp forest in southern California. The result is a reserve that encompasses similar to 42% of the kelp forest. Our approach differs fundamentally from many other marine reserve siting methods in which goals of area, diversity, or biomass are targeted a priori. Rather, our method was developed to determine how large a reserve must be within a specific area to protect a self-sustaining assemblage of exploited species. The algorithm is applicable across different ecosystems, spatial scales, and for any number of species. The result is a reserve in which habitat value is optimized for a predetermined set of exploited species against the area left open to exploitation. The importance of fine-scale habitat definitions for the exploited species off La Jolla is exemplified by the spatial pattern of habitats and the stability of these habitats within the kelp forest, both of which appear to be determined by ocean microclimate.

biological-physical coupling; conservation; habitat; kelp forest; Macrocystis; marine protected area; marine reserve; reserve design; reserve size; stability

Parnell, E. P., C. E. Lennert-Cody, L. Geelen, L. D. Stanley and P. K. Dayton. 2005. Effectiveness of a small marine reserve in southern California. Marine Ecology Progress Series. 296:39-52.

While relatively small, the San Diego–La Jolla Ecological Reserve is one of the oldest in California, and it contains giant-kelp-forest, boulder-reef, submarine-canyon and sandy-shelf habitats. We evaluated the effectiveness of this ‘no-take’ marine reserve and gauged its success according to the goals implicit in its design. To overcome the lack of data prior to its establishment, we employed habitat-specific analyses. Our study comprised 4 components: (1) an historical review of its establishment; (2) a survey of conspicuous species in kelp-forest, submarine-canyon, and boulderreef habitats; (3) comparisons with historical data; (4) a public survey regarding awareness, knowledge, and support of the reserve. Despite 30 yr of protection, only a few sessile or residential species exhibit positive effects of protection, and most fished species have decreased in abundance inside the reserve. However, the reserve protects the largest remaining populations of green abalone Haliotis fulgens and vermillion rockfish Sebastes miniatus in the area, which therefore represent important sources of larvae. Implementation and enforcement of coastal reserves depends on public support, but the results of the public survey indicated a lack of knowledge of the reserve, highlighting the need for improved public education in this respect. The results of the study reflect the limited value of small reserves and document the inadequacy of inside/outside comparisons as tests of reserve effectiveness when baseline and historical data are lacking.

Marine protected area; Reserves; Kelp; Abalone; Urchins; Submarine-canyon; Rockfish; Public opinion.

Parsons, D. M. and D. B. Eggleston. (2006) Human and natural predators combine to alter behavior and reduce survival of Caribbean spiny lobster. Journal of Experimental Marine Biology and Ecology 334: 196-205.

Fishing disturbance can have indirect negative effects on animal behavior and survival, but receives little attention compared to measures of direct fisheries extraction. We quantified changes in the density of Caribbean spiny lobster Panulirus argus when exposed to experimental human disturbance and injury typical of sport-diver harvest attempts in the field. A complementary study in a large seawater arena quantified lobster sheltering behavior and survival when exposed to the single and combined effects of human disturbance and triggerfish Balistes capriscus predators. Human disturbance and injury of lobsters in the field caused lobsters to emigrate from shelters that had been typically occupied over successive days. Similarly, both the presence of triggerfish predators and human disturbance promoted decreased lobster shelter fidelity to individual shelters in the arena. Overall shelter use and gregariousness increased in the presence of natural triggerfish predators but not as a function of human disturbance. Decreased shelter use and gregariousness by lobsters when exposed to human disturbance may have contributed to their decreased survival when exposed simultaneously to triggerfish. These results highlight how human disturbance and injury of lobsters can alter their behavior and reduce subsequent survival in the presence of their natural predators, and illustrate the need to incorporate the negative effects of sport-divers into models that estimate population demographic rates.

Behavioral mechanisms; Indirect effects; Panulirus argus; Sport divers; Sub-lethal human disturbance; Unobserved mortality

Pastoors, M.A., A.D. Rijnsdorp, and F.A. Van Beek. 2000. Effects of a partially closed area in the North Sea (''plaice box'') on stock development of plaice. ICES Journal of Marine Science 57: 1014-1022.

The ''plaice box'' is a partially closed area in the North Sea, established in 1989 to reduce the discarding of undersized plaice (Pleuronectes platessa) in the main nursery areas, and thereby to enhance recruitment to the fishery. In contrast to the expected positive effects, yield and spawning stock biomass have decreased. The effects of the plaice box are evaluated by analyzing the relevant factors and processes (natural and anthropogenic) that affect recruitment. It is shown that the Dutch beam trawl effort has decreased in two phases. During 1989-1993, when the plaice box was closed only during the second and third quarter, effort was reduced to around 40% of the original level. When the box was also closed in the fourth (1994) and first quarter (1995 onwards), effort decreased to around 6%. The effort reduction would imply a reduction in discard mortality if all other factors had remained constant. However, a reduced growth rate and possibly a higher rate of natural mortality may have counteracted the reduction in fishing effort. The apparent changes in growth and mortality coincided with changes in the North Sea ecosystem that occurred in the early 1990s but may also be related to a response to the change in beam trawl effort.

Pederson, H. G. and C. R. Johnson. 2006. Predation of the sea urchin Heliocidaris erythrogramma by rock lobsters (Jasus edwardsii) in no-take marine reserves. Journal of Experimental Marine Biology and Ecology. 336:120-134.

The formation of sea urchin ‘barrens’ on shallow temperate rocky reefs is well documented. However there has been much conjecture about the underlying mechanisms leading to sea urchin barrens, and relatively little experimentation to test these ideas critically. We conducted a series of manipulative experiments to determine whether predation mortality is an important mechanism structuring populations of the sea urchin Heliocidaris erythrogramma in Tasmania. Tethered juvenile and adult sea urchins experienced much higher rates of mortality inside no-take marine reserves where sea urchin predators were abundant compared to adjacent fished areas where predators were fewer. Mortality of tagged (but not tethered) sea urchins was also notably higher in marine reserves than in adjacent areas open to fishing. When a range of sizes of sea urchins was exposed to three sizes of rock lobsters in a caging experiment, juvenile sea urchins were eaten more frequently than larger sea urchins by all sizes of rock lobster, but only the largest rock lobsters (N120 mm CL) were able to consume large adult sea urchins. Tagging (but not tethering) juvenile and adult sea urchins in two separate marine reserves indicated that adult sea urchins experience higher predation mortality than juveniles, probably because juveniles can shelter in cryptic microhabitat more effectively. In a field experiment in which exposure of sea urchins to rock lobster (Jasus edwardsii) and demersal reef fish predators was manipulated, rock lobsters were shown to be more important than fish as predators of adult sea urchins in a marine reserve. We conclude that predators, and particularly rock lobsters, exert significant predation mortality on H. erythrogramma in Tasmanian marine reserves, and that adult sea urchins are more vulnerable than smaller cryptic individuals. Fishing of rock lobsters is likely to reduce an important component of mortality in H. erythrogramma populations.

Demersal fish; Marine reserves; Predation mortality; Rock lobsters; Sea urchins; Size-specific mortality

Pelc, R. A., R. R. Warner, S. D. Gaines, and C. B. Paris. (2010).Detecting larval export from marine reserves. PNAS Early Edition: 1-6.

Marine reserve theory suggests that where large, productive populations are protected within no-take marine reserves, fished areas outside reserves will benefit through the spillover of larvae produced in the reserves. However, empirical evidence for larval export has been sparse. Here we use a simple idealized coastline model to estimate the expected magnitude and spatial scale of larval export from no-take marine reserves across a range of reserve sizes and larval dispersal scales. Results suggest that, given the magnitude of increased production typically found in marine reserves, benefits from larval export are nearly always large enough to offset increased mortality outside marine reserves due to displaced fishing effort. However, the proportional increase in recruitment at sites outside reserves is typically small, particularly for species with long-distance (on the order of hundreds of kilometers) larval dispersal distances, making it very difficult to detect in field studies. Enhanced recruitment due to export may be detected by sampling several sites at an appropriate range of distances from reserves or at sites downcurrent of reserves in systems with directional dispersal. A review of existing empirical evidence confirms the model's suggestion that detecting export may be difficult without an exceptionally large differential in production, short-distance larval dispersal relative to reserve size, directional dispersal, or a sampling scheme that encompasses a broad range of distances from the reserves.

spillover, marine protected areas, recruitment, dispersal, fisheries

Pelletier, D., J. Claudet, J. Ferraris, L. Benedetti-Cecchi and J. A. Garcia-Charton. 2008. Models and indicators for assessing conservation and fisheries-related effects of marine protected areas. Canadian Journal of Fisheries and Aquatic Sciences. 65:765-779.

Two kinds of approaches have been used for assessing conservation and fisheries-related effects of marine protected areas (MPAs): (i) statistical modelling based on field data and (ii) mathematical modelling quantifying the consequences of MPAs on the dynamics of populations, communities, and fisheries. Statistical models provide a diagnostic on the impact of MPAs on the ecosystem and resources; they are also needed for devising and assessing sampling designs for monitoring programs. Dynamic models enable exploration of the consequences of MPA designs and other management policies. We briefly review how each of these approaches has been implemented up to now in the literature and identify potential indicators of MPA effects that can be obtained from each approach to provide scientific advice for managers. Methodological gaps that impede the assessment of MPA effects and the construction of appropriate indicators are then discussed, and recent developments in this respect are presented. We finally propose ways to reconcile the two approaches based on their complementarity to derive suitable indicators to support decision making. In this respect, we suggest in addition that MPA managers should be associated from the beginning to the design and construction of indicators.

Pelletier, D., J. A. García-Charton, J. Ferraris, G. David, O. Thébaud, Y. Letourneur, J. Claudet, M. Amand, M. Kulbicki, and R. Glazon. (2005). Designing indicators for assessing the effects of marine protected areas on coral reef ecosystems: A multidisciplinary standpoint. Aquatic Living Resources 18: 15-33.

The present paper aims at identifying and assessing indicators of the effects of Marine Protected Areas (MPAs) in coral reef regions, based on a bibliography review in ecology, economics and social sciences. First the various effects studied within each of these domains and the variables used to measure them were censused. Potential ecological indicators were assessed through their link with the question used (here termed "relevance") and their "effectiveness" which encompasses the issues of precision, accuracy and statistical power. Relevance and effectiveness were respectively measured by the frequency of use of each indicator and the proportion of significant results in the reviewed articles. For social and economic effects, the approach was not possible due to the low number of references; we thus discussed the issue of finding appropriate indicators for those fields. Results indicate: 1- the unbalance in literature between disciplines; 2- the need for protocols and methodologies which include controls in order to assess MPA effects; 3- an important proportion of ecological indicators with low effectiveness; 4- the large number of ecological effects still not studied or not demonstrated at present.

Marine Protected Areas, Ecological, economic and social indicators, Pluridisciplinary, Coral reef ecosystems, Coastal management

Peterson, M. N., M. J. Peterson and T. R. Peterson. 2005. Conservation and the myth of consensus. Conservation Biology. 19:762-767.

Environmental policy makers are embracing consensus-based approaches to environmental decision making in an attempt to enhance public participation in conservation and facilitate the potentially incompatible goals of environmental protection and economic growth. Although such approaches may produce positive results in immediate spatial and temporal contexts and under some forms of governance, their overuse has potentially dangerous implications for conservation within many democratic societies. We suggest that environmental decision making rooted in consensus theory leads to the dilution of socially powerful conservation metaphors and legitimizes current power relationships rooted in unsustainable social constructions of reality. We also suggest an argumentative model of environmental decision making rooted in ecology will facilitate progressive environmental policy by placing the environmental agenda on firmer epistemological ground and legitimizing challenges to current power hegemonies that dictate unsustainable practices.

Petrosillo, I., G. Zurlini, M. E. Corliano, N. Zaccarelli and M. Dadamo. 2007. Tourist perception of recreational environment and management in a marine protected area. Landscape and Urban Planning. 79:29-37.

A person's socio-economic status, cultural ties, and past experiences influence how people perceive environmental quality. In the case of tourism, people using protected areas can differ in many ways, including their personal characteristics and perception about the recreation environment. This research addresses the general problem of tourist perception in a marine protected area (MPA), focusing on tourists' awareness of being in an MPA, tourists' opinion on management activities, the importance of natural attractiveness components, tourists' satisfaction with recreational experience and willingness to come back, and on tourists' awareness of their environmental impacts. Data were collected by means of questionnaires, and statistical analyses were performed according to four main variables: awareness to be in an MPA, gender, education level, and place of residence. Answers, and consequently, perceptions were highly dependent on education level and the place of residence, and surprisingly the unaware tourists came from neighbouring municipalities, in particular from the province of Brindisi where the MPA is located. This research put in evidence that a different perception can be due to environmental and park related attitudes, but also to the profile of visitors who frequent protected areas. In this respect, we stress the importance of a better identification of visitors' profile, for a better management of tourism development in an MPA.

Tourists' perception; Recreational ecosystem services; Conservation management; Marine protected area; Visitors' profile

Pister, B. (2009) Urban marine ecology in southern California: the ability of riprap structures to serve as rocky intertidal habitat. Marine Biology 156: 861-873.

Increasing human populations along marine coastlines has lead to increasing urbanization of the marine environment. Despite decades of investigations on terrestrial ecosystems, the effect of urbanization on marine life is not well understood. Riprap is the rocky rubble used to build jetties, breakwaters, and armored shorelines. Roughly 30% of the southern California shoreline supports some form of riprap, while 29% of the shoreline is natural rocky substrate. Astonishingly few studies have investigated this anthropogenic rocky habitat even though it rivals a natural habitat in area on a regional scale along a coastline that has been extensively studied. In this study, I compared the diversity and community structure of exposed rocky intertidal communities on four riprap and four natural sites in southern California. I ask the following questions: (1) does diversity or community composition differ between intertidal communities on riprap and natural rocky habitats in southern California, (2) if so, which organisms contribute to those differences, (3) which physical factors are contributing to these differences, and (4) do riprap habitats support higher abundances of invasive species than natural habitats? On average, riprap and natural rocky habitats in wave exposed environments in southern California did not differ from each other in diversity or community composition when considering the entire assemblage. However, when only mobile species were considered, they occurred in greater diversity on natural shores. These differences appear to be driven by wave exposure. The presence of invasive species was negligible in both natural and riprap habitats.

Urban marine ecology, California, intertidal community

Pitchford, J. W., E. A. Codling and D. Psarra. 2007. Uncertainty and sustainability in fisheries and the benefit of marine protected areas. Ecological Modeling. 207:286-292.

Over-exploitation of fisheries is a serious and immediate global problem that current management policies struggle to solve. Scientists and managers accept that newstrategies based on a long-term approach are required for future fisheries management policies. But to succeed, such strategies are likely to require more than just attempts by management to control annual levels of exploitation. Recent studies show that using MPAs (marine protected areas, marine reserves) can improve yield as well as protect stocks and sustain fishery viability. In this paper, we use a deliberately simple model, which describes an exploited fishery as a nonlinear dynamical system close to a point of bifurcation; small stochastic perturbations can therefore build up to cause fishery collapse. Extending the model shows that a MPA can buffer this stochasticity and alleviate the propensity to collapse. The model illustrates two main points: (i) evaluating fisheries management strategies such as MPAs in a deterministic framework is inherently misleading; at worst it leads to fishery extinction, at best it fails to maximise yield; (ii) management strategies that are designed explicitly to buffer uncertainty in the system can provide a sustainable and productive fishery. Compared with harvest control rules based on uncertain estimates of stock size, our simulations indicate that MPAs can substantially reduce the risk of fisheries collapse for only a very small cost to total yield.

Marine Protected Areas; Fisheries management; Harvesting strategies; Stochastic simulations; Uncertainty

Planes, S., G. P. Jones and S. R. Thorrold. 2009. Larval dispersal connects fish populations in a network of marine protected areas. Proceedings of the National Academy of Sciences. 106:5693-5697.

Networks of no-take marine protected areas (MPAs) have been widely advocated for the conservation of marine biodiversity. But for MPA networks to be successful in protecting marine populations, individual MPAs must be self-sustaining or adequately connected to other MPAs via dispersal. For marine species with a dispersive larval stage, populations within MPAs require either the return of settlement-stage larvae to their natal reserve or connectivity among reserves at the spatial scales at which MPA networks are implemented. To date, larvae have not been tracked when dispersing from one MPA to another, and the relative magnitude of local retention and connectivity among MPAs remains unknown. Here we use DNA parentage analysis to provide the first direct estimates of connectivity of a marine fish, the orange clownfish (Amphiprion percula), in a proposed network of marine reserves in Kimbe Bay, Papua New Guinea. Approximately 40% of A. percula larvae settling into anemones in an island MPA at 2 different times were derived from parents resident in the reserve. We also located juveniles spawned by Kimbe Island residents that had dispersed as far as 35 km to other proposed MPAs, the longest distance that marine larvae have been directly tracked. These dispersers accounted for up to 10% of the recruitment in the adjacent MPAs. Our findings suggest that MPA networks can function to sustain resident populations both by local replenishment and through larval dispersal from other reserves. More generally, DNA parentage analysis provides a direct method for measuring larval dispersal for other marine organisms.

Amphiprion percula; connectivity; parentage analyses; self-recruitment

Planque, B., J. Fromentin, P. Cury, K. F. Drinkwater, S. Jennings, R. I. Perry and S. Kifani. 2010. How does fishing alter marine populations and ecosystems sensitivity to climate? Journal of Marine Systems. 79:403-417.

Evidence has accumulated that climate variability influences the state and functioning of marine ecosystems. At the same time increasing pressure from exploitation and other human activities has been shown to impact exploited and non-exploited species and potentially modify ecosystem structure. There has been a tendency among marine scientists to pose the question as a dichotomy, i.e., whether (1) "natural" climate variability or (2) fishery exploitation bears the primary responsibility for population declines in fish populations and the associated ecosystem changes. However, effects of both climate and exploitation are probably substantially involved in most cases. More importantly, climate and exploitation interact in their effects, such that climate may cause failure in a fishery management scheme but that fishery exploitation may also disrupt the ability of a resource population to withstand, or adjust to, climate changes. Here, we review how exploitation, by altering the structure of populations and ecosystems, can modify their ability to respond to climate. The demographic effects of fishing (removal of large-old individuals) can have substantial consequences on the capacity of populations to buffer climate variability through various pathways (direct demographic effects, effects on migration, parental effects). In a similar way, selection of population sub-units within meta-populations may also lead to a reduction in the capacity of populations to withstand climate variability and change. At the ecosystem level, reduced complexity by elimination of species, such as might occur by fishing, may be destabilizing and could lead to reduced resilience to perturbations. Differential exploitation of marine resources could also promote increased turnover rates in marine ecosystems, which would exacerbate the effects of environmental changes. Overall (and despite the specificities of local situations) reduction in marine diversity at the individual, population and ecosystem levels will likely lead to a reduction in the resilience and an increase in the response of populations and ecosystems to future climate variability and change. Future management schemes will have to consider the structure and functioning of populations and ecosystems in a wider sense in order to maximise the ability of marine fauna to adapt to future climates.

Climate-fishing interactions; Demography; Marine ecosystems; Resilience

Pollnac, R., P. Christie, J. E. Cinner, T. Dalton, T. M. Daw, G. E. Forrester, N. A. J. Graham, and T. R. McClanahan. (2010). Marine reserves as linked social–ecological systems PNAS Early Edition: 1-4.

Marine reserves are increasingly recognized as having linked social and ecological dynamics. This study investigates how the ecological performance of 56 marine reserves throughout the Philippines, Caribbean, and Western Indian Ocean (WIO) is related to both reserve design features and the socioeconomic characteristics in associated coastal communities. Ecological performance was measured as fish biomass in the reserve relative to nearby areas. Of the socioeconomic variables considered, human population density and compliance with reserve rules had the strongest effects on fish biomass, but the effects of these variables were region specific. Relationships between population density and the reserve effect on fish biomass were negative in the Caribbean, positive in the WIO, and not detectable in the Philippines. Differing associations between population density and reserve effectiveness defy simple explanation but may depend on human migration to effective reserves, depletion of fish stocks outside reserves, or other social factors that change with population density. Higher levels of compliance reported by resource users was related to higher fish biomass in reserves compared with outside, but this relationship was only statistically significant in the Caribbean. A heuristic model based on correlations between social, cultural, political, economic, and other contextual conditions in 127 marine reserves showed that high levels of compliance with reserve rules were related to complex social interactions rather than simply to enforcement of reserve rules. Comparative research of this type is important for uncovering the complexities surrounding human dimensions of marine reserves and improving reserve management.

coral reef, human-environment interactions, socioeconomic, social-ecological system, marine protected area

Quesne, W. J., S. J. Hawkins and J. G. Shepherd. 2007. A comparison of no-take zones and traditional fishery management tools for managing site-attached species with a mixed larval pool. Fish and Fisheries. 8:181-195.

No-take zones (NTZs) can generate higher larval production by sessile, sedentary and site-attached species per unit area than in exploited areas, and may increase recruitment and yield compared to status quo management. Whilst NTZs may be considered an essential part of optimal management, few studies have specifically compared the effects of NTZs with those of correctly applied gear and effort controls. A yield-per-recruit (YPR) population model, based on the sedentary abalone Haliotis laevigata, was used to compare the effects of management by minimum landing size (MLS), effort limitation and NTZs, either singularly or in combination. Initially, a minimum basic YPR model was used. Three additional assumptions were sequentially added to the model to see if they affected conclusions drawn from the model. The additional assumptions were the inclusion of: (i) a length–fecundity relationship; (ii) an age-dependent natural mortality function; and (iii) mortality of undersized individuals due to fishery operations. In the absence of undersized mortality caused by fishing, under virtually all conditions the population is best managed with a combination of MLS and effort control, without any NTZs. For simulations that included mortality of undersized individuals in the fished area, under nearly all circumstances NTZs were considered an essential part of optimal fishery
management, and management incorporating NTZs greatly increased the sustainable yield that could be taken.

Abalone; fisheries management; marine protected areas; minimum landing size; no-take zones; yield-per-recruit

Richardson, E. A., M. J. Kaiser, G. Edwards-Jones and H. P. Possingham. 2006. Sensitivity of Marine-Reserve Design to the Spatial Resolution of Socioeconomic Data. Conservation Biology. 20:1191-1202.

Socioeconomic considerations should have an important place in reserve design. Systematic reserve selection tools allow simultaneous optimization for ecological objectives while minimizing costs but are seldom used to incorporate socioeconomic costs in the reserve-design process. The sensitivity of this process to biodiversity data resolution has been studied widely but the issue of socioeconomic data resolution has not previously been considered. We therefore designed marine reserves for biodiversity conservation with the constraint of minimizing commercial fishing revenue losses and investigated how economic data resolution affected the results. Incorporating coarse-resolution economic data from official statistics generated reserves that were only marginally less costly to the fishery than those designed with no attempt to minimize economic impacts. An intensive survey yielded fine-resolution data that, when incorporated in the design process, substantially reduced predicted fishery losses. Such an approach could help minimize fisher displacement because the least profitable grounds are selected for the reserve. Other work has shown that low-resolution biodiversity data can lead to underestimation of the conservation value of some sites, and a risk of overlooking the most valuable areas, and we have similarly shown that low-resolution economic data can cause underestimation of the profitability of some sites and a risk of inadvertently including these in the reserve. Detailed socioeconomic data are therefore an essential input for the design of cost-effective reserve networks.

Rioja-Nieto, R. and C. Sheppard. (2008).Effects of management strategies on the landscape ecology of a Marine Protected Area. Ocean & Coastal Management 51: 397-404.

Marine Protected Areas (MPAs) are important tools for the conservation of coral reefs and associated habitats. We utilized a Geographic Information System (GIS) to evaluate the effect of marine park management in one of Mexico's most important MPAs by comparing benthic habitat structure between the MPA and an adjacent unmanaged region. Characters compared included measure of habitat b-diversity, total area and fragmentation of 15 different habitat classes, and size distributions of the patches of each of those classes. Habitat fragmentation distribution was similar between regions, but significantly higher b-diversity was seen in the managed area, and differences also occurred in the area and fragmentation of several substrate classes. The results suggest that management strategies which limit physical impact on benthic habitats are having a positive effect on the integrity of several important habitats in the MPA.

Mexico, marine protected areas, habitat classes, fragmentation

Roberts, C.M., J.A. Bohnsack, F. Gell, J.P. Hawkins and R. Goodridge. 2001. Effects of Marine Reserves on Adjacent Fisheries. Science 294:1920-1923.

Marine reserves have been widely promoted as conservation and fishery management tools. There are robust demonstrations of conservation benefits, but fishery benefits remain controversial. We show that marine reserves in Florida (United States) and St. Lucia have enhanced adjacent fisheries. Within 5 years of creation, a network of five small reserves in St. Lucia increased adjacent catches of artisanal fishers by between 46 and 90%, depending on the type of gear the fishers used. In Florida, reserve zones in the Merritt Island National Wildlife Refuge have supplied increasing numbers of world record-sized fish to adjacent recreational fisheries since the 1970s. Our study confirms theoretical predictions that marine reserves can play a key role in supporting fisheries.

Roberts, C.M., G. Branch, R.H. Bustamante, J.C. Castilla, J. Dugan, B.S. Halpern, K.D. Lafferty, H. Leslie, J. Lubchenco, D. McArdle, M. Ruckelshaus, and R.R. Warner. 2003. Application of Ecological Criteria in Selecting Marine Reserves and Developing Reserve Networks. Ecological Applications 13(1) Supplement: S215-S228.

Marine reserves are being established worldwide in response to a growing recognition of the conservation crisis that is building in the oceans. However, designation of reserves has been largely opportunistic, or protective measures have been implemented (often overlapping and sometimes in conflict) by different entities seeking to achieve different ends. This has created confusion among both users and enforcers, and the proliferation of different measures provides a false sense of protection where little is offered. This paper sets out a procedure grounded in current understanding of ecological processes, that allows the evaluation and selection of reserve sites in order to develop functional, interconnected networks of fully protected reserves that will fulfill multiple objectives. By fully protected we mean permanently closed to fishing and other resource extraction. We provide a framework that unifies the central aims of conservation and fishery management, while also meeting other human needs such as the provision of ecosystem services (e.g., maintenance of coastal water quality, shoreline protection, and recreational opportunities). In our scheme, candidate sites for reserves are evaluated against 12 criteria focused toward sustaining the biological integrity and productivity of marine systems at both local and regional scales. While a limited number of sites will be indispensable in a network, many will be of similar value as reserves, allowing the design of numerous alternative, biologically adequate networks. Devising multiple network designs will help ensure that ecological functionality is preserved throughout the socioeconomic evaluation process. Too often, socioeconomic criteria have dominated the process of reserve selection, potentially undermining their efficacy. We argue that application of biological criteria must precede and inform socioeconomic evaluation, since maintenance of ecosystem functioning is essential for meeting all of the goals for reserves. It is critical that stakeholders are fully involved throughout this process. Application of the proposed criteria will lead to networks whose multifunctionality will help unite the objectives of different management entities, so accelerating progress toward improved stewardship of the oceans.

Roberts, C.M., S. Andelman, G. Branch, R.H. Bustamante, J.C. Castilla, J. Dugan, B.S. Halpern, K.D. Lafferty, H. Leslie, J. Lubchenco, D. McArdle, H.P. Possingham, M. Ruckelshaus, and R.R. Warner. 2003. Ecological Criteria for Evaluating Candidate Sites for Marine Reserves. Ecological Applications 13(1) Supplement: S199-S214.

Several schemes have been developed to help select the locations of marine reserves. All of them combine social, economic, and biological criteria, and few offer any guidance as to how to prioritize among the criteria identified. This can imply that the relative weights given to different criteria are unimportant. Where two sites are of equal value ecologically, then socioeconomic criteria should dominate the choice of which should be protected. However, in many cases, socioeconomic criteria are given equal or greater weight than ecological considerations in the choice of sites. This can lead to selection of reserves with little biological value that fail to meet many of the desired objectives. To avoid such a possibility, we develop a series of criteria that allow preliminary evaluation of candidate sites according to their relative biological values in advance of the application of socioeconomic criteria. We include criteria that, while not strictly biological, have a strong influence on the species present or ecological processes. Our scheme enables sites to be assessed according to their biodiversity, the processes which underpin that diversity, and the processes that support fisheries and provide a spectrum of other services important to people. Criteria that capture biodiversity values include biogeographic representation, habitat representation and heterogeneity, and presence of species or populations of special interest (e.g., threatened species). Criteria that capture sustainability of biodiversity and fishery values include the size of reserves necessary to protect viable habitats, presence of exploitable species, vulnerable life stages, connectivity among reserves, links among ecosystems, and provision of ecosystem services to people. Criteria measuring human and natural threats enable candidate sites to be eliminated from consideration if risks are too great, but also help prioritize among sites where threats can be mitigated by protection. While our criteria can be applied to the design of reserve networks, they also enable choice of single reserves to be made in the context of the attributes of existing protected areas. The overall goal of our scheme is to promote the development of reserve networks that will maintain biodiversity and ecosystem functioning at large scales. The values of ecosystem goods and services for people ultimately depend on meeting this objective.

Roberts, C. M., J. A. Bohnsack, F. Gell, J. P. Hawkins and R. Goodridge. 2001. Effects of marine reserves on adjacent fisheries. Science. 294:1920-1923.

Marine reserves have been widely promoted as conservation and fishery management tools. There are robust demonstrations of conservation benefits, but fishery benefits remain controversial. We show that marine reserves in Florida (United States) and St. Lucia have enhanced adjacent fisheries. Within 5 years of creation, a network of five small reserves in St. Lucia increased adjacent catches of artisanal fishers by between 46 and 90%, depending on the type of gear the fishers used. In Florida, reserve zones in the Merritt Island National Wildlife Refuge have supplied increasing numbers of world record-sized fish to adjacent recreational fisheries since the 1970s. Our study confirms theoretical predictions that marine reserves can play a key role in supporting fisheries.

Rodwell, L.D., E.B. Barbier, C.M. Roberts, and T.R. McClanahan. 2003. The importance of habitat quality for marine reserve - fishery linkages. Canadian Journal Fisheries Aquatic Science 60: 171-181.

We model marine reserve - fishery linkages to evaluate the potential contribution of habitat-quality improvements inside a marine reserve to fish productivity and fishery catches. Data from Mombasa Marine National Park, Kenya, and the adjacent fishery are used. Marine reserves increase total fish biomass directly by providing refuge from exploitation and indirectly by improving fish habitat in the reserve. As natural mortality of the fish stock decreases in response to habitat enhancement in the reserve, catches increase by up to 2.6 tonnes (t)·km-2·year-1 and total fish biomass by up to 36 t·km-2. However, if habitat-quality improvement reduces the propensity of fish to move out of the reserve, catches may fall by up to 0.9 t·km-2·year-1. Our results indicate that habitat protection in reserves can underpin fish productivity and, depending on its effects on fish movements, augment catches.

Rogers-Bennett, L. 1998 Marine Protected Areas and the Red Urchin Fishery. In: Taking a Look at California's Ocean Resources: An Agenda for the Future. 1998. Magoon, O.R., H. Converse, B. Baird, M. Miller-Henson, editors. Reston, VA (USA): Vol. 1, pp. 412-423.

There is a growing consensus among fishery scientists that marine protected areas (MPAs) offer a promising approach for managing California's fished populations. California's leading fishery the red urchin fishery has been declining for almost 10 years despite traditional management efforts. The biological characteristics of red urchins including their long life, slow growth, and sporadic recruitment suggest that previous landings came from an accumulation of old animals. MPAs can be used to ensure a portion of the catch remains to reproduce and replenish fished habitats. The most effective MPAs will encompass reproductively important "source" habitats. Shallow habitats in northern California appear to be "source" habitats because they harbor high densities of both brood stock and juvenile urchins. There is now a large body of evidence supporting the establishment of MPAs as a fishery management tool for benthic invertebrates.

Rogers-Bennett, L., P. Haaker, K. Karpov. 2000.Selecting and Evaluating Marine Protected Areas for Abalone in California. Journal of Shellfish Research. 19(1):530-1.

Abalone populations have declined dramatically in California, resulting in the closure of the commercial and recreational fisheries south of San Francisco. Marine Protected Areas (MPAs) have been proposed as a tool to help restore declining abalone populations, Haliotis spp. but more information is needed to locate MPAs and to determine the efficacy of such areas. One simple yet practical plan for siting MPAs is to analyze historical cumulative catch data to identify areas which once supported large populations of target species. To do this, we examined spatially explicit catch data from the commercial fishery (1950-1996) to direct the selection of MPAs for abalone in California. San Clemente Island was the area of peak abundance of the now endangered white abalone, Haliotis sorenseni and the soon to be listed black, Haliotis cracherodi, pink, Haliotis corrugata, and green, Haliotis fulgens abalone, making this island uniquely suitable as an abalone restoration MPA. We also examined fishery independent data which included abundances and size frequency distributions of abalone inside and outside MPAs to examine the efficacy of existing MPAs. We found that the Anacapa Island MPA in the Channel Islands, where abalone fishing is excluded, supports higher populations of abalone than fished sites. Furthermore, remote parts of the MPA that are not under the observation of the reserve manager, failed to protect pink abalone stocks which declined to zero as did neighboring fished sites. Therefore, we caution that while abalone abundances may be higher inside MPAs, effective enforcement of these areas is critical to their success.

Rogers-Bennett, L., Haaker, P.L., Karpov, K.A., Kushner, D.J. 2002. Using Spatially Explicit Data to Evaluate Marine Protected Areas for Abalone in Southern California. Conservation Biology 16(5): 1308-1317.

Abalone populations have declined dramatically in southern California. The white abalone (Haliotis sorenseni) is now (2001) on the federal endangered species list. To aid in the restoration of white, pink (H. corrugata), and green abalone (H. fulgens), productive marine protected areas need to be selected. We used spatially explicit fishery data (1950-1995) to identify the most productive marine areas in southern California. To assess the role of existing marine protected areas we compared fishery-independent data (1983-2001) inside protected and fished areas. San Clemente Island produced the greatest cumulative catches of white, pink, and green abalone, the most white abalone per hectare of deep reef (25-65 m), and the most green abalone per kilometer of rocky shoreline. Santa Barbara Island, however, produced 10 times more pink abalone per hectare of kelp canopy, making this area an excellent candidate for restoration and protection. Pink abalone surveyed in the Kelp Forest Monitoring Program were most abundant at three sites surrounding Anacapa Island: (1) protected, (2) protected but less visible, and (3) fished. The protected sites, despite having lower abundances of pink abalone initially (1983), had significantly more abalone ( H = 9.0; df = 2; p = 0.011) than the nearby fished site over time. Size-frequency distributions revealed that the protected site had more (30%) commercial-size abalone ( greater than or equal to 158 mm shell length) than the less visible site (6%) or the fished site (2%). Mean size was significantly larger at the protected site, yielding the highest estimate of biomass and potential egg production (2555 million eggs/site/year) of all the sites. Marine protected areas need to be selected and enforced so that abalone-restoration efforts can be enacted before remnant populations die. Restoration sites for a wide variety of depleted species can be selected based on previous levels of productivity identified by spatially explicit data.

Rogers-Bennett, L. and J.S. Pearse. 2001. Indirect Benefits of Marine Protected Areas for Juvenile Abalone. Conservation Biolology. 15(3):642-7.

Marine protected areas (MPAs) designed to provide harvest refugia for red sea urchins (Strongylocentrotus franciscanus) offer a unique opportunity to study the indirect effects of urchin fishing on subtidal communities. Sea urchins may provide important cryptic microhabitat for juvenile abalone sheltering beneath urchin spines in shallow habitats worldwide. We investigated the abundance of juvenile (3-90 mm) red abalone, (Haliotis rufescens) and the rare flat (at<90 mm) abalone (H. walallensis) on protected and fished rocky reefs in California. Abalone abundance surveys were conducted inside 24 x 30 m plots on three protected reefs with red sea urchins present and three fished reefs where red sea urchins were removed by commercial or experimental fishing. Significantly more juvenile abalone were found in 1996 and 1997 on protected reefs with urchins present than on fished reefs (chi super(2) = 188, df = 1, p < 0.001). Juvenile red abalone abundance was not correlated with local adult red abalone abundance or habitat rugosity. One-third of the juveniles inside the MPAs were found under the urchins' spine canopy, as were a suite of unfished marine organisms. In the laboratory, juvenile abalone survived better (chi super(2) = 7.31, df = 1, p < 0.01) in crab predation experiments in which red sea urchins were available as shelter. Fishing red urchins reduced structural complexity, potentially decreasing microhabitat available for juvenile abalone. This example demonstrates how MPAs designed for one fished species may help other species, illustrating their usefulness for ecosystem-based fishery management and marine conservation.

Rooper, C. N., D. R. Gunderson, B. M. Hickey. (2006). An examination of the feasibility of passive transport from coastal spawning grounds to estuarine nursery areas for English sole. Estuarine, Coastal and Shelf Science 68: 609-618.

English sole recruitment has been linked to environmental conditions occurring during their 6-10 week pelagic egg and larval stages, prior to their appearance in nursery estuaries during their first summer. The purpose of this study was to predict the spawning locations of juvenile English sole observed in estuaries to assess the feasibility of passive transport of egg and larval stages. Current meter data were used to back calculate the transport trajectories of 19 cohorts of English sole observed as juveniles during estuarine trawl surveys. Only six of these cohorts were predicted to be spawned outside the Oregon, Washington shelf system, assuming passive transport of eggs and larvae. Predicted egg and larval trajectories indicate that most of the English sole found in Oregon and Washington estuaries were spawned off the coast of Washington, with some spawning off northern California and central Oregon. Although these results are not consistent with the presumed spawning locations for the Oregon and Washington shelf, they indicate that passive transport assumptions may be adequate to preserve the larvae in the coastal system until settlement.

larval transport; English sole; larval retention; California current

Roy, K., A. G. Collins, B. J. Becker, E. Begovic and J. M. Engle. 2003. Anthropogenic impacts and historical decline in body size of rocky intertidal gastropods in southern California. Ecology Letters. 6:205-211.

The diverse fauna and flora of rocky intertidal ecosystems are being impacted by the activities of rapidly increasing coastal populations in many regions of the world. Human harvesting of intertidal species can lead to significant changes in body sizes of these taxa. However, little is known about the temporal trajectories of such size declines and more importantly, the long-term effects of chronic human impacts. Furthermore, it is unclear whether sizes of species not directly targeted for harvesting are also declining through indirect effects. Here we use historical (extending back to 1869) and field survey data covering 200 km of mainland southern California coast to show that human activities have led to significant and widespread declines in body sizes of rocky intertidal gastropod species over the last century. These declines, initiated several decades ago, are continuing and contrary to expectation, they are not restricted to species harvested for human consumption. Data from the only national park in this area, where conservation laws are strictly imposed, demonstrate that negative ecological impacts can be ameliorated if existing laws are enforced.

Body size; gastropods; human impacts; Southern California

Ruckelshaus, M., T. Klinger, N. Knowlton, D. P. DeMaster. (2008). Marine Ecosystem-based Management in Practice: Scientific and Governance Challenges. BioScience 58(1): 53-63.

Ecosystem-based management (EBM) in the ocean is a relatively new approach, and existing applications are evolving from more traditional management of portions of ecosystems. Because comprehensive examples of EBM in the marine environment do not yet exist, we first summarize EBM principles that emerge from the fisheries and marine social and ecological literature. We then apply those principles to four cases in which large parts of marine ecosystems are being managed, and ask how including additional components of an EBM approach might improve the prospects for those ecosystems. The case studies provide examples of how additional elements of EBM approaches, if applied, could improve ecosystem function. In particular, two promising next steps for applying EBM are to identify management objectives for the ecosystem, including natural and human goals, and to ensure that the governance structure matches with the scale over which ecosystem elements are measured and managed.

fisheries, marine food webs, marine ecosystem-based management, marine ecosystems, ocean zoning

Russ, G. R., A. C. Alcala, A. P. Maypa, H. P. Calumpong and A. T. White. 2004. Marine reserves benefits local fisheries. Ecological Applications. 14:597-606.

The utility of no-take marine reserves as fisheries-management tools is controversial. It is hypothesized that marine reserves will help to sustain fisheries external to them by becoming net exporters of adults (the ‘‘spillover effect’’) and net exporters of propagules (the ‘‘recruitment effect’’). Local fishery benefits from spillover will likely generate support from fishing communities for marine reserves. We used underwater visual census to show that biomass of Acanthuridae (surgeonfish) and Carangidae (jacks), two families of reef fish that account for 40–75% of the fishery yield from Apo Island, Philippines, tripled in a well-protected no-take reserve over 18 years (1983–2001). Biomass of these families did not change significantly over the same period at a site open to fishing. The reserve protected 10% of the total reef fishing area at the island. Outside the reserve, biomass of these families increased significantly closer to (200–250 m) than farther away from (250–500 m) the reserve boundary over time. We used published estimates of fishery catch and effort, and fisher interviews (creel surveys) to show that the total catch of Carangidae and Acanthuridae combined at Apo Island was significantly higher after (1985– 2001) than before (1981) reserve establishment. Hook-and-line catch per unit effort (CPUE) at the island was 50% higher during 1998–2001 (reserve protected 16–19 years) than during 1981–1986 (pre-reserve and early phases of reserve protection). Total hook-and-line effort declined by 46% between 1986 and 1998–2001. Hook-and-line CPUE of Acanthuridae was significantly higher close to (within 200 m) than far from the reserve. CPUE of Carangidae was significantly higher away from the reserve, possibly reflecting a local oceanographic effect. The benefits of the reserve to local fisheries at the island were higher catch, increased catch rate, and a reduction in fishing effort. The fishery and tourism benefits generated by the reserve have enhanced the living standard of the fishing community.

Acanthuridae; Carangidae; catch rates; coral reef fish; fisheries management; fishery yields; marine reserves, benefits to local fisheries; Philippines (Apo Island); spillover effect

Russ, G. R. and A. C. Alcala. 1996. Marine reserves: rates and patterns of recovery and decline of large predatory fish. Ecological Applications. 6:947-961.

A major objective of the use of marine reserves in management of coral reef fisheries is protection of a critical spawning stock biomass to ensure recruitment supply to fished areas via larval dispersal. However, very little empirical evidence exists on the rates and patterns of increase of density and biomass of target species following the closure of a coral reef or part of a reef, nor on how quickly any gains potentially useful to fisheries can be lost if reserves are subsequently opened to fishing. This paper presents empirical evidence derived from the visual monitoring of density and biomass of large predatory coral reef fish (Serranidae (Epinephelinae), Lutjanidae, Lethrinidae and Carangidae as a group) in two small marine reserves and at two control sites in the Philippines from 1983 to 1993. At one reserve (Sumilon) a complex history of management allowed seven measurements of density and biomass at durations of reserve protection ranging from -2 (i.e., fished for 2 yr) to 9 yr. At the second reserve (Apo), seven measurements were taken at durations of reserve protection ranging from 1 to 11 yr. Density of large predators provided an excellent indicator of the effects of marine reserve protection and fishing. Density decreased significantly twice when the Sumilon reserve was opened to fishing (1985, 1993), and increased significantly three times following durations of marine reserve protection of 5 yr (Sumilon reserve and nonreserve sites, 1987-1991) and >6 yr (Apo reserve beyond 1988). Density of large predators at the Apo nonreserve site (open to fishing) did not change significantly, remaining low throughout the study. Significant positive linear correlations of mean density of large predators with years of reserve protection were observed at both reserves. The rates of increase were 1.15 and 0.72 fish.1000 m2.yr-1at Sumilon and Apo reserves, respectively, with mean density ranges of ~ 4-17 fish.1000 m2 (-2 to 9 yr of protection) at Sumilon and 0.5-9.5 fish/1000 m2 (1-11 yr of protection) at Apo. The pattern of increase of mean biomass with years of reserve protection was more curvilinear than that of mean density, particularly at Sumilon, where a slow increase was observed in the first 3-5 yr (reflecting delayed recruitment and a natural delay to the period of maximum individual mass growth), followed by an increasing rate over the next 4 yr. Mean biomass ranges were ~ 1.5-18 kg/1000 m2 (-2 to 9 yr of protection) at Sumilon and 1-10.5 kg/1000 m2 (1-11 yr of protection) at Apo. At Sumilon reserve, 2 and 1.5 yr of unregulated fishing, respectively, eliminated density and biomass gains accumulated over 5 and 9 yr of marine reserve protection.

Biomass; coral reef fish; decline rates; fish density; fisheries management; fishing impact; indicator species; large predator; marine reserves; Philippines; recovery rates; visual census

Saenz-Arroyo, A., C. M. Roberts, J. Torre, M. Carino-Olvera and J. P. Hawkins. 2006. The value of evidence about past abundance: marine fauna of the Gulf of California through the eyes of 16th to 19th century travellers. Fish and Fisheries. 7:128-146.

Eyewitness accounts written by early travellers to ‘the new worlds’ provide valuable insights into how seascapes once looked. Although this kind of information has been widely used to chart human impacts on terrestrial ecosystems, it has been greatly overlooked in the marine realm. Here we present a synthesis of 16th to 19th century travellers’ descriptions of the Gulf of California and its marine wildlife. The diaries written by conquerors, pirates, missionaries and naturalists described a place in which whales were ‘innumerable,’ turtles were ‘covering the sea’ and large fish were so abundant that they could be taken by hand. Beds of pearl oysters that are described had disappeared by 1940 and only historical documents reveal the existence of large, widespread, deep pearl oyster reefs, whose ecology and past functions we know little about. Disqualifying the testimonies of early visitors to a region as ‘anecdotal’ is dangerous; it may lead to setting inappropriate management targets that could lead to the extinction of species that are rare today but were once much more abundant. Moreover, it represents unfair historical judgement on the work of early natural historians, scholars and scientists. We suggest that the review and analytical synthesis of reports made by early travellers should become part of the pre-requisites for deciding how to manage marine ecosystems today.

Extinction; historical ecology; over-exploitation; shifting baseline syndrome

Sala, E., O. Aburto-Oropeza, G. Paredes, I. Parra, J.C. Barrera, and P.K. Dayton. 2002. A General Model for Designing Networks of Marine Reserves. Science 298: 1999-1993.

There is debate concerning the most effective conservation of marine biodiversity, especially regarding the appropriate location, size, and connectivity of marine reserves. We describe a means of establishing marine reserve networks by using optimization algorithms and multiple levels of information on biodiversity, ecological processes (spawning, recruitment, and larval connectivity), and socioeconomic factors in the Gulf of California. A network covering 40% of rocky reef habitat can fulfill many conservation goals while reducing social conflict. This quantitative approach provides a powerful tool for decisionmakers tasked with siting marine reserves.

Salomon, A. K., J. L. Ruesink and R. E. DeWreede. 2006. Population viability, ecological processes and biodiversity: Valuing sites for reserve selection. Biological Conservation. 128:79-92.

No-take reserves constitute one tool to improve conservation of marine ecosystems, yet criteria for their placement, size, and arrangement remain uncertain. Representation of biodiversity is necessary in reserve planning, but will ultimately fail for conservation unless factors affecting species’ persistence are also incorporated. This study presents an empirical example of the divergent relationships among multiple metrics used to quantify a site’s conservation value, including those that address representation (habitat type, species richness, species diversity), and others that address ecological processes and viability (density and reproductive capacity of a keystone species, in this case, the black chiton, Katharina tunicata). We characterized 10 rocky intertidal sites across two habitats in Barkley Sound, British Columbia, Canada, according to these site metrics. High-richness and high-production sites for K. tunicata were present in both habitat types, but high richness and high-production sites did not overlap. Across sites, species richness ranged from 29 to 46, and adult K. tunicata varied from 6 to 22 individuals m2. Adult density was negatively correlated with species richness, a pattern that likely occurs due to post-recruitment growth and survival because no correlation was evident with non-reproductive juveniles. Sites with high adult density also contributed disproportionately greater potential reproductive output (PRO), defined by total gonad mass. PRO varied by a factor of five across sites and was also negatively correlated with species richness. Compromise or relative weighting would be necessary to select valuable sites for conservation because of inherent contradictions among some reserve selection criteria. We suspect that this inconsistency among site metrics will occur more generally in
other ecosystems and emphasize the importance of population viability of strongly interacting species.

Reserve selection and design; Marine reserve; Species richness; Keystone species; Population viability

Salz, R. J. and D. K. Loomis. 2004. Saltwater anglers' attitudes towards marine protected areas. Fisheries. 29:10-17.

Attempts to establish "no-take" marine reserves in the United States have engendered strong opposition from sportfishing interest groups. This study investigated northeastern saltwater anglers' attitudes towards several hypothetical marine protected area (MPA) alternatives. Support for MPAs decreased with increasing level of restrictiveness. Anglers attitudes towards the establishment of "catch-and-release" MPAs were somewhat divided. The majority of those surveyed were opposed to "no-take" reserves. If "no-take" reserves are to be accepted by anglers, managers need to convince them of the advantages of incorporating this innovative management tool over more traditional fishery regulations alone. Anglers were more opposed to MPAs that restrict recreational fishing within state waters as compared to similar MPAs sited in federal waters. In general, anglers from New York and New Jersey held more favorable MPA attitudes than did anglers from Rhode Island, New Hampshire, and Massachusetts. Anglers who were members of a fishing organization were more opposed to MPAs than were non-members. Anglers whose most preferred species was striped bass were more opposed to "no-take" reserves than were anglers whose most preferred species was summer flounder. Attitudinal data on MPAs collected early in the planning process can help highlight important differences in management preferences among stakeholder subgroups, identify management alternatives, justify preferred management actions, and reduce the likelihood of alienating important stakeholder groups.

Sanchirico, J.N., and J.E. Wilen. 2002. The Impacts of Marine Reserves on Limited-Entry Fisheries. Natural Resources Modeling 15: 291-310.

We utilize a spatial bioeconomic model to investigate the impacts of creating reserves on limited-entry fisheries. We find that reserve creation can produce win-win situations where aggregate biomass and the common license (lease) price increase. These situations arise in biological systems where dispersal processes are prevalent and the fishery prior to reserve creation is operating at effort levels in a neighborhood of open-access levels. We also illustrate that using strictly biological criteria for siting reserves (e.g., setting aside the most biological productive areas) will likely induce the most vociferous objections from the fishing industry. In general, we find that the dispersal rate and the degree the patches are connected play a significant role on the net impacts on the fishing sector.

Scholz, A., K. Bonzon, R. Fujita, N. Benjamin, N. Woodling, P. black, and C. Streinback. 2004. Participatory socioeconomic analysis: drawing on fishermen's knowledge for marine protected area planning in California. Marine Policy. 28(4): 335-349.

The purpose of this pilot study was to test the utility of geospatial analysis tools for eliciting and integrating fishermen's knowledge into marine protected area (MPA) planning processes in California, United States. A participatory design yielded 30 local knowledge interviews that were coded for socioeconomic and biodiversity information. The resulting information is useful in understanding past conflicts around MPA siting proposals and for identifying likely sources of agreement and disagreement. Products include a protocol for rapid socioeconomic assessment; a database of fishermen's knowledge and information; and a geographic information system for further use in California's MPA planning process.

Schroeder, D. M. and M. S. Love. 2002. Recreational fishing and marine fish populations in California. CalCOFI Report. 43:182-190.

We present and review information regarding recreational angling and exploited marine fish populations in California. A comparison of rockfish assemblages among three differently fished areas (one open to all fishing, another open only to recreational fishing, and a de facto marine protected area) revealed large differences in fish density, size structure, and species composition. The area open to all fishing harbored the highest density of rockfishes (7,212 fish/ha), although the size structure and species composition were dominated by small fishes. The area open only to recreational fishing had the lowest rockfish density (423 fish/ha) and a size structure also dominated by small fishes. The de facto protected area possessed high fish density (5,635 fish/ha), but here the size structure and species composition shifted toward larger fishes compared with the two fished areas. Two species federally listed as overfished, cowcod and bocaccio, had 32-fold and 408-fold higher densities, respectively, in the de facto reserve than observed inside the recreational fishing area, and 8-fold and 18-fold higher densities, respectively, than observed in the area open to all fishing. For 17 nearshore fish species, we compared landings by recreational anglers and commercial harvesters and found that, for 16 species, recreational angling was the primary source of fishing mortality. We illustrate the potential damaging effects of mortality associated with catch-and-release programs on long-lived fish populations. Based on this information, we recommend that legislators and natural resource managers reject the assumption that recreational fishing is a low or no impact activity until specific studies can demonstrate otherwise.

Schroeter, S.C, D. C. Reed, D. J. Kushner, J. A. Estes, and D. S. Ono. 2001.The use of marine reserves in evaluating the dive fishery for the warty sea cucumber (Parastichopus parvimensis) in California, U.S.A. Canadian Journal of Fisheries and Aquatic Sciences 58: 1773-1781.

Management of sustainable fisheries depends upon reliable estimates of stock assessment. Assessment of many stocks is based entirely on fishery-dependent data (e.g., catch per unit effort), which can be problematic. Here we use fishery-independent data on stock size, collected within and outside of no-take reserves before and after the onset of fishing, to evaluate the status of the dive fishery for warty sea cucumbers, Parastichopus parvimensis, in southern California. Long-term monitoring data showed that abundance decreased throughout the Channel Islands within 3-6 years after the onset of fishing. No significant changes in the abundance of P. parvimensis were observed at the two non-fished reserve sites, although densities tended to increase following onset of the fishery. Before-after, control-impact (BACI) analyses of seven fished and two non-fished sites implicated fishing mortality as the cause of 33-83% stock declines. In sharp contrast, stock assessment based on CPUE data showed no declines and a significant increase at one island. To date, most discussion on marine reserves has focused on the protection and enhancement of exploited populations. Our study demonstrates the critically important, but often overlooked, role that marine reserves can play in providing reliable information on stock assessment.

Selkoe, K. A., A. Vogel and S. D. Gaines. 2007. Effects of ephemeral circulation on recruitment and connectivity of nearshore fish populations spanning Southern and Baja California. Marine Ecology Progress Series. 351:209-220.

The California sheephead Semicossyphus pulcher and the kelp bass Paralabrax clathratus are members of a suite of nearshore reef species that have subtropical taxonomic affiliations and important fisheries in the Southern California Bight (SCB). This suite shows high interannual fluctuation in recruitment success in the SCB, with no known cause. One hypothesis gaining mention in management literature is the idea that recruitment booms in the SCB originate from larvae swept poleward from Mexico during El Niño flow-reversal events. If true, SCB stocks may be reliant on Mexican sources. We used 3 diverse sources of data to investigate the likelihood of El Niño-driven recruitment success and connectivity for S. pulcher and P. clathratus. Time series of larval abundance revealed that neither species shows synchrony with El Niño Southern Oscillation (ENSO) cycles that would suggest influx of Mexican larvae during El Niño flow reversals. P. clathratus age structure data show that recruitment strength is unrelated to ENSO cycles but correlates to spring sea surface temperature in the SCB, indicating that local environmental factors drive interannual variation in local production. Genetic analyses of 14 populations of P. clathratus with 7 microsatellite loci revealed distinct patterns of genetic structure in the SCB and Baja California that reflect localized connectivity patterns and contradict patterns that would be expected if dispersal primarily occurred during El Niño flow reversals. While these results support the importance of protecting local sources in the SCB, continued study of dispersal and recruitment at large scales will help characterize the causes of interannual variation and the exact scale of cross-border connectivity.

Baja California; El Niño; ENSO; Fish recruitment; Kelp bass; Paralabrax; Semicossyphus pulcher; Southern California Bight

Sethi, S. A. and R. Hilborn. 2008. Interactions between poaching and management policy affect marine reserves as conservation tools. Biological Conservation. 141:506-516.

To explore the effects of poaching within marine reserve boundaries under three different management policies this analysis uses a simple age-structured reserve model based on yield maximization or reproductive thresholds of Black rockfish (Sebastes melanops). Departures from the traditional assumptions of full compliance to reserve boundaries alter the conclusions of prior modeling work that demonstrate yield equivalence to no-reserve effort control management and augmented reproductive benefits when small reserves are implemented. By degrading the recruitment subsidization effect to non reserve areas from protected reserve populations, poaching resulted in negative externalities for compliant fishermen in open areas in terms of yield and degraded the reproductive output and age structure of the system. All three policies required effort reduction in open areas as a response to poaching in reserves. The strength of the impacts from poaching varied with policy choice and harvest intensity in the reserve, where at the highest level of poaching modeled here (15% annual exploitation rate of the vulnerable reserve population) biological and fishery benefits of implementing reserves were totally negated. Under the assumptions of this model, a policy managing for a reproductive threshold that excludes the reserve population is the precautionary choice if poaching is likely. The results of this exercise emphasize the importance of garnering compliance to reserve boundaries from resource users for spatial closures to be successful ocean management tools.

Marine reserves; Noncompliance; Poaching; Fisheries management

Shanks, A.L., B.A. Grantham, and M.H. Carr. 2003. Propagule Dispersal Distance and the Size and Spacing of Marine Reserves. Ecological Applications 13(1) Supplement: S159-S169.

This study compiled available information on the dispersal distance of the propagules of benthic marine organisms and used this information in the development of criteria for the design of marine reserves. Many benthic marine organisms release propagules that spend time in the water column before settlement. During this period, ocean currents transport or disperse the propagules. When considering the size of a marine reserve and the spacing between reserves, one must consider the distance which propagules disperse. We could find estimates of dispersal distance for 32 taxa; for 25 of these, we were also able to find data on the time the propagules spent dispersing. Dispersal distance ranged from meters to thousands of kilometers, and time in the plankton ranged from minutes to months. A significant positive correlation was found between the log-transformed duration in the plankton and the log-transformed dispersal distance (r 5 0.7776, r2 5 0.60, df 5 1, 25, P 5 0.000); the more time propagules spend in the water column the further they tend to be dispersed. The frequency distribution of the log-transformed dispersal distance is bimodal (kurtosis 5 21.29, t 5 24.062, P , 0.001) with a gap between 1 and 20 km. Propagules that dispersed ,1 km spent less time in the plankton (,100 h), or if they remained in the plankton for a longer period, they tended to remain in the waters near the bottom. Propagules that dispersed .20 km spent more than 300 h in the plankton. The bimodal nature of the distribution suggests that evolutionary constraints may reduce the likelihood of evolving mid-range dispersal strategies (i.e., dispersal between 1 and 20 km) resulting in two evolutionarily stable dispersal strategies: dispersal ,1 km or .;20 km. We suggest that reserves be designed large enough to contain the short-distance dispersing propagules and be spaced far enough apart that long-distance dispersing propagules released from one reserve can settle in adjacent reserves. A reserve 4-6 km in diameter should be large enough to contain the larvae of short-distance dispersers, and reserves spaced 10-20 km apart should be close enough to capture propagules released from adjacent reserves.

Shears, N. T., R. V. Grace, N. R. Usmar, V. Kerr and R. C. Babcocka. 2006. Long-term trends in lobster populations in a partially protected vs. no-take marine park. Biological Conservation. 132:222-231.

Increasing the level of protection afforded to the marine environment requires assessment of the efficacy of existing marine protected areas (MPAs) in protecting exploited species. Long-term data from before and after the establishment of MPAs provide a rare but valuable opportunity to assess these effects. In this study we present long-term data (1977– 2005) from before and after park establishment, on the abundance of spiny lobster Jasus edwardsii from fixed sites in a no-take marine park and a recreationally fished marine park, to assess the efficacy of no-take vs. partial protection. Lobster densities were comparable between both marine parks prior to park establishment, but the response of lobster populations differed markedly following protection. On average, legal-sized lobster were eleven times more abundant and biomass 25 times higher in the no-take marine park following park establishment, while in the partially protected marine park there has been no significant change in lobster numbers. Furthermore, no difference was found in densities of legal-sized lobster between the partially protected marine park and nearby fully-fished sites (<1 per 500m2). Long-term data from fully fished and partially protected sites suggest long-term declines in lobster populations and reflect regional patterns in catch per unit effort estimates for the fishery. The long-term patterns presented provide an unequivocal example of the recovery of lobster populations in no-take MPAs, but clearly demonstrate that allowing recreational fishing in MPAs has little benefit to populations of exploited species such as J. edwardsii.

Marine protected area; Marine reserve; Mimiwhangata Marine Park; New Zealand; Rock lobster; Tawharanui Marine Park

Shears, N. T. and R. C. Babcock. 2003. Continuing trophic cascade effects after 25 years of no-take marine reserve protection. Marine Ecology Progress Series. 246:1-16.

Between 1978 and 1996 benthic communities in the Leigh Marine Reserve shifted from being dominated by sea urchins to being dominated by macroalgae. This was a result of a trophic cascade thought to be an indirect effect of increased predator abundance. We assessed further changes in communities from 1996 to 2000, differences in benthic communities between reserve and adjacent unprotected sites, and the stability of these patterns from 1999 to 2001. Since 1996, densities of sea urchins Evechinus chloroticus have continued to decline in shallow areas of the reserve (<8 m), and all sites classified as urchin barrens in 1978 are now dominated by large brown algae. Comparisons between reserve and non-reserve sites revealed differences consistent with a trophic cascade at reserve sites. The greatest differences in algal communities between reserve and non-reserve sites occurred at depths where E. chloroticus was most abundant (4 to 6 m). Reserve sites had lower urchin densities and reduced extent of urchin barrens habitat with higher biomass of the 2 dominant algal species (Ecklonia radiata and Carpophyllum maschalocarpum). At reserve sites densities of exposed E. chloroticus (openly grazing the substratum) declined so that urchin barrens were completely absent by 2001. Lower density of the limpet Cellana stellifera and higher densities of the turbinid gastropod Cookia sulcata at reserve sites are thought to be responses to changes in habitat structure, representing additional indirect effects of increased predators. The overall difference in community types between reserve and non-reserve sites remained stable between 1999 and 2001. Localised urchin mortality events due to an unknown agent were recorded at some sites adjacent to the marine reserve. Only at 1 of these sites did exposed urchins decline below the critical density of 1 m-2, which resulted in the total replacement of urchin barrens with macroalgae-dominated habitats. At other sites urchin barrens have remained stable. Declines in the limpet C. stellifera occurred across all sites between 1999 and 2001 and may be indirectly associated with urchin declines. Long-term changes in benthic communities in the Leigh reserve and the stability of differences between reserve and nonreserve sites over time are consistent with gradual declines in urchin densities due to increased predation on urchins, thus providing further evidence for a trophic cascade in this system. The rapid declines in urchin numbers at some unprotected sites, however, demonstrate how short-term disturbances, such as disease, may result in shifts in community types over much shorter time frames.

Benthic community structure; Macroalgae; Macro-invertebrate herbivores; Marine protected areas; Northeastern New Zealand; Sea urchins; Temporal change

Shears, N.T. and R.C. Babcock. 2002. Marine reserves demonstrate top-down control of community structure on temperate reefs. Oecologia 132:131-142.

Replicated ecological studies in marine reserves and associated unprotected areas are valuable in examining top-down impacts on communities and the ecosystem-level effects of fishing. We carried out experimental studies in two temperate marine reserves to examine these top-down influences on shallow subtidal reef communities in northeastern New Zealand. Both reserves examined are known to support high densities of predators and tethering experiments showed that the chance of predation on the dominant sea urchin, Evechinus chloroticus, within both reserves was approximately 7 times higher relative to outside. Predation was most intense on the smallest size class (30-40 mm) of tethered urchins, the size at which urchins cease to exhibit cryptic behaviour. A high proportion of predation on large urchins could be attributed to the spiny lobster, Jasus edwardsii. Predation on the smaller classes was probably by both lobsters and predatory fish, predominantly the sparid Pagrus auratus. The density of adult Evechinus actively grazing the substratum in the urchin barrens habitat was found to be significantly lower at marine reserve sites (2.2±0.3 m-2) relative to non-reserve sites (5.5±0.4 m-2). There was no difference in the density of cryptic juveniles between reserve and non-reserve sites. Reserve populations were more bimodal, with urchins between 40 and 55 mm occurring at very low numbers. Experimental removal of Evechinus from the urchin barrens habitat over 12 months lead to a change from a crustose coralline algal habitat to a macroalgal dominated habitat. Such macroalgal habitats were found to be more extensive in both reserves, where urchin densities were lower, relative to the adjacent unprotected areas that were dominated by urchin barrens. The patterns observed provide evidence for a top-down role of predators in structuring shallow reef communities in northeastern New Zealand and demonstrate how marine reserves can reverse the indirect effects of fishing and re-establish community level trophic cascades.

Shipp, R.L. 2000. No Take Marine Protected Areas (nMPAs) as a fishery management tool, a pragmatic perspective. A report to the FishAmerica foundation. 8 pp.

Executive Summary:

Marine Protected Areas (MPAs) are portions of the marine environment which are protected from some or all human activity. Often these are proposed as a safeguard against collapse of fish stocks, although there are numerous other suggested purposes for their establishment. "No take" MPAs (hereafter referenced as nMPAs) are those from which no harvest is allowed. Other types include those where certain types of harvest are prohibited, which are reserved for certain user groups, or which are protected from other human activities such as drilling or dredging.

Establishment of nMPAs may have numerous beneficial purposes. However, as a tool for fisheries management, where optimal and/or maximum sustainable yield is the objective, nMPAs are generally not as effective as traditional management measures, and are not appropriate for the vast majority of marine species. This is because most marine species are far too mobile to remain within an nMPA and/or are not overfished. For those few species that could receive benefit, creation of nMPAs would have an adverse effect on optimal management of sympatric forms.

Eight percent of US fish stocks of the Exclusive Economic Zone (EEZ) are reported to be experiencing overfishing. The finfish stocks included in this number are primarily pelagic or highly mobile species, movement patterns that don't lend themselves to benefit from nMPAs. Thus a very small percentage, something less than 2 %, depending on mobility potentials, is likely to benefit from creation of these no-take zones. However, many of these species have come under management within the last decade, employing more traditional fishery management measures, and are experiencing recovery.

MPAs (both "no take" and other types) can serve a positive function as a management tool in protecting breeding aggregations, in helping recovery of severely overfished and unmanaged insular fish populations with little connectivity to adjacent stocks, and in protecting critical habitat which can be damaged by certain fishing methods.

Shipp, R.L. 2003. A Perspective on Marine Reserves as a Fishery Management Tool. Fisheries 28: 10-21.

Marine protected areas (MPAs) are portions of the marine environment which are protected from some or all human activity. Where extraction of living resources is forbidden, these MPAs are best referred to as marine reserves. Often these are proposed as a safeguard against collapse of fish stocks, although reserves may have numerous other beneficial purposes. However, as a tool for fisheries management, where optimal and/or maximum sustainable yield is the objective, I submit that reserves are generally not as effective as traditional management measures, and are not appropriate for the vast majority of marine species. This is because most marine species are far too mobile to remain within a reserve and/or are not overfished. However, in the United States, of those marine fishes that are experiencing overfishing or are overfished, most have come under management within the last decade, employing more traditional fishery management measures, and are experiencing recovery. For those few species which could receive benefit, creation of reserves would have an adverse effect on harvest potentials of sympatric forms.

Siegel, D. A., S. Mitarai, C. Costello, S. D. Gaines, B. E. Kendall, R. R. Warner and K. B. Winters. 2008. The stochastic nature of larval connectivity among nearshore marine populations. Proceedings of the National Academy of Sciences. 105:8974-8979.

Many nearshore fish and invertebrate populations are overexploited even when apparently coherent management structures are in place. One potential cause of mismanagement may be a poor understanding and accounting of stochasticity, particularly for stock recruitment. Many of the fishes and invertebrates that comprise nearshore fisheries are relatively sedentary as adults but have an obligate larval pelagic stage that is dispersed by ocean currents. Here, we demonstrate that larval connectivity is inherently an intermittent and heterogeneous process on annual time scales. This stochasticity arises from the advection of pelagic larvae by chaotic coastal circulations. This result departs from typical assumptions where larvae simply diffuse from one site to another or where complex connectivity patterns are created by transport within spatially complicated environments. We derive a statistical model for the expected variability in larval settlement patterns and demonstrate how larval connectivity varies as a function of different biological and physical processes. The stochastic nature of larval connectivity creates an unavoidable uncertainty in the assessment of fish recruitment and the resulting forecasts of sustainable yields.

coastal oceanography; fisheries; marine ecology

Sladek Nowlis, J., C.M. Roberts. 1999. Fisheries benefits and optimal design of marine reserves. Fishery Bulletin 97: 604-616.

We used fishery population models to assess the potential for marine fishery reserves, areas permanently closed to fishing, to enhance long-term fishery yields. Our models included detailed life history data. They also included the key assumptions that adults did not cross reserve boundaries and that larvae mixed thoroughly across the boundary but were retained sufficiently to produce a stock-recruitment relationship for the management area. We analyzed the results of these models to determine how reserve size, fishing mortality, and life history traits, particularly population growth potential, affected the fisheries benefits from reserves. We predict that reserves will enhance catches from any overfished population that meets our assumptions, particularly heavily overfished populations with low population growth potential. We further predict that reserves can enhance catches when they make up 40% or more of fisheries management areas, significantly higher proportions than are typical of existing reserve systems. Finally, we predict that reserves in systems that meet our assumptions will reduce annual catch variation in surrounding fishing grounds. The fisheries benefits and optimal design of marine reserves in any situation depended on the life history of the species of interest as well as its rate of fishing mortality. However, the generality of our results across a range of species suggest that marine reserves are a viable fisheries management alternative.

Smith, J. R. and S. N. Murray. 2005. The effects of experimental bait collection and trampling on a Mytilus californianus mussel bed in southern California. Marine Biology. 147:699-706.

Rocky shores in southern California are heavily visited by humans. At sites used by recreational fishers, the effects of foot traffic combined with the collection of mussels for bait may reduce mussel cover and create mussel-free gaps. To test this hypothesis, the effects of trampling and bait-removal on mussel populations were experimentally examined. Plots in a mussel bed were subjected to monthly combinations of trampling (0, 150, or 300 steps) and simulated bait-removal (0 or 2 removed mussels). Although the experiment was done during a period of high natural disturbance associated with the 1997–1998 ENSO, plots receiving treatments experienced significantly greater reductions in  mussel cover, mass, and density than controls. These results indicate that visitor foot traffic and bait-removal by fishers can significantly reduce mussel cover, density, biomass, and sizes.

Smith, J. R., P. Fong and R. F. Ambrose. 2008. The Impacts of Human Visitation on Mussel Bed Communities Along the California Coast: Are Regulatory Marine Reserves Effective in Protecting These Communities? Environmental Management. 41:599-612.

Rocky intertidal habitats frequently are used by humans for recreational, educational, and subsistence-harvesting purposes, with intertidal populations damaged by visitation activities such as extraction, trampling, and handling. California Marine Managed Areas, particularly regulatory marine reserves (MRs), were established to provide legal protection and enhancement of coastal resources and include prohibitions on harvesting intertidal populations. However, the effectiveness of MRs is unclear as enforcement of no-take laws is weak and no regulations protect intertidal species from other detrimental visitor impacts such as trampling. The goal of this study was twofold: (1) to determine impacts from human visitation on California mussel populations (Mytilus californianus) and mussel bed community diversity; and (2) to investigate the effectiveness of regulatory MRs in reducing visitor impacts on these populations. Surveys of mussel populations and bed-associated diversity were compared: (1) at sites subjected to either high or low levels of human use, and (2) at sites either unprotected or with regulatory protection banning collecting. At sites subjected to higher levels of human visitation, mussel populations were significantly lower than low-use sites. Comparisons of mussel populations inside and outside of regulatory MRs revealed no consistent pattern suggesting that California no-take regulatory reserves may have limited effectiveness in protecting mussel communities. In areas where many people visit intertidal habitats for purposes other than collecting, many organisms will be affected by trampling, turning of rocks, and handling. In these cases, effective protection of rocky intertidal communities requires an approach that goes beyond the singular focus on collecting to reduce the full suite of impacts.

Marine reserves; Anthropogenic disturbance; Rocky intertidal; Mytilus californianus; Mussel bed community; Trampling; Collecting

Smith, M. D., J. Lynham, J. N. Sanchirico, and J. A. Wilson. 2006. Political economy of marine reserves: Understanding the role of opportunity costs. PNAS Early Edition: 1-6.

The creation of marine reserves is often controversial. For decision makers, trying to find compromises, an understanding of the timing, magnitude, and incidence of the costs of a reserve is critical. Understanding the costs, in turn, requires consideration of not just the direct financial costs but also the opportunity costs associated with reserves. We use a discrete choice model of commercial fishermen's behavior to examine both the short-run and long-run opportunity costs of marine reserves. Our results can help policymakers recognize the factors influencing commercial fishermen's responses to reserve proposals. More generally, we highlight the potential drivers behind the political economy of marine reserves.

marine protected areas, fishing behavior, bioeconomics, metapopulation, opportunity cost

Smith, M. D., J. Zhang and F. C. C. Coleman. 2006. Effectiveness of marine reserves for large-scale fisheries management. Canadian Journal of Fisheries and Aquatic Sciences. 63:153-164.

As more no-take marine reserves are established, the importance of evaluating effectiveness retrospectively is growing. This paper adapts methods from program evaluation to quantify the effects of establishing a marine reserve on fisheries using fishery-dependent data. The approach analyzes the effects of a policy at the individual vessel level and accommodates the coarse spatial resolution of fishing logbooks. It illuminates implicit assumptions in previous retrospective analyses of marine reserves that are unlikely to hold for large-scale fisheries. We illustrate the empirical model with an application to the Gulf of Mexico reef-fish fishery. Isolating the effects of reserves requires a full accounting of multiple gear production technologies, heterogeneity in vessel captain skill, spatial heterogeneity of fish stocks, seasonal patterns in abundance, the effects of coexisting management policies, and the possibility that the harvest sector anticipates reserve establishment. We find that the effect of two recently established marine reserves on catch is negative and trending downward, though the reserves have only been in place for 4.5 years.

Smith, M. D. and J.E. Wilen. 2003. Economic impacts of marine reserves: the importance of spatial behavior. Journal of Environmental Economics and Management 46: 183-206.

Marine biologists have shown virtually unqualified support for managing fisheries with marine reserves, signifying a new resource management paradigm that recognizes the importance of spatial processes in exploited systems. Most modeling of reserves employs simplifying assumptions about the behavior of fishermen in response to spatial closures. We show that a realistic depiction of fishermen behavior dramatically alters the conclusions about reserves. We develop, estimate, and calibrate an integrated bioeconomic model of the sea urchin fishery in northern California and use it to simulate reserve policies. Our behavioral model shows how economic incentives determine both participation and location choices of fishermen. We compare simulations with behavioral response to biological modeling that presumes that effort is spatially uniform and unresponsive to economic incentives. We demonstrate that optimistic conclusions about reserves may be an artifact of simplifying assumptions that ignore economic behavior.

Soh, S.K., Dr.R. Gunderson, D.H. Ito. 2001. The potential role of marine reserves in the management of shortraker rockfish (Sebastes borealis) and rougheye rockfish (S. Aleutianus) in the Gulf of Alaska. Fishery Bulletin 99(1): 168-179.

Shortraker and rougheye rockfish (Sebastes borealis and S. aleutianus) have been an independent management subgroup of the Gulf of Alaska slope rockfish assemblage since 1991. Special concerns are proposed for the management of these species because they are very slow growing, long-lived, and commercially important. Marine reserves (harvest refugia) have often been proposed as a valuable management tool for mitigating overfishing and maintaining species and habitat diversity. Their effectiveness in fisheries management, however, is poorly understood and concepts regarding their use are largely untested. Our study investigated the potential role of harvest refugia in the management of these two species by using a Geographic Information System (GIS) application to design harvest refugia networks of varying spatial extent. Twenty-year projections employing a population dynamics model were used to compare ending biomass and fishing mortality under the current management system with biomass and fishing mortality under refuge management systems. The results indicate that harvest refugia can be used to greatly reduce discards and serial overfishing of substocks without reducing current catch levels.

Sonnenholzner, J. I., L. B. Ladah and K. D. Lafferty. 2007. Cascading effects of fishing on Galapagos rocky reef communities. Marine Ecology Progress Series. 343:77-85.

A replicated comparison of heavily and lightly fished areas in the Galapagos suggested that fishing predators led to an increase in herbivores and a dramatic shift in the algal community toward crustose barrens. We sampled 10 highly fished and 10 lightly fished shallow rocky reefs in the southeastern area of the Galapagos Marine Reserve, Ecuador. Negative associations between consumers and resources suggested top-down control. At cold sites, there was a negative association between slate-pencil urchins Eucidaris galapagensis and non-coralline algae. In addition, at cold sites, pencil urchins were less abundant where there were many predators. An indirect positive association between predators and non-coralline algae occurred at warm and cold sites. Fishing appeared to affect this trophic cascade. The spiny lobster Panulirus penicillatus, the slipper lobster Scyllarides astori, and the Mexican hogfish Bodianus diplotaenia were significantly less abundant at highly fished sites. Urchin density was higher at highly fished sites. Non-coralline algae were nearly absent from highly fished sites where a continuous carpet of the anemone Aiptasia sp. was recorded and the algal assemblage was mainly structured by encrusting coralline and articulated calcareous algae.

Trophic cascade; Fishing; Predation; Population structure; Eucidaris galapagensis; Galapagos Marine Reserve; Ecuador

Sonnenholzner, J. I., L. B. Ladah and K. D. Lafferty. 2009. Cascading effects of fishing on Galapagos rocky reef communities: reanalysis using corrected data. Marine Ecology Progress Series. 375:209-218.

This article replaces Sonnenholzner et al. (2007; Mar Ecol Prog Ser 343:77-85), which was retracted on September 19, 2007, due to errors in entry of data on sea urchins. We sampled 10 highly fished and 10 (putatively) lightly fished shallow rocky reefs in the southeastern area of the Galapagos Marine Reserve, Ecuador. After the correction, these are the new results: there was a negative association between slate-pencil urchins Eucidaris galapagensis and non-coralline algae. In addition, pencil urchins were less abundant where there were many predators. An indirect positive association between predators and non-coralline algae occurred. Fishing appeared to affect this trophic cascade. The spiny lobster Panulirus penicillatus, the slipper lobster Scyllarides astori, and the Mexican hogfish Bodianus diplotaenia were significantly less abundant at highly fished sites. Urchin density was higher at highly fished sites. Non-coralline algae were nearly absent from highly fished sites, where a continuous carpet of the anemone Aiptasia sp. was recorded, and the algal assemblage was mainly structured by encrusting coralline and articulated calcareous algae.

Trophic cascade; Fishing; Predation; Population structure; Eucidaris galapagensis; Galapagos Marine Reserve; Ecuador

Speckman, S. G., J. F. Piatt and A. M. Springer. 2004. Small boats disturb fish-holding marbled murrelets. Northwestern Naturalist. 85:32-34.

Marbled murrelet; Brachyramphus marmoratus; at-sea behavior; chick feeding; boat disturbance; southeast Alaska

Starr, R.M, M.H. Carr, J. Caselle, J.A. Estes, C. Syms, D.A. VenTresca, and M. M. Yoklavich. 2004. A review of the ecological effectiveness of subtidal marine reserves in central California, Part I: Synopsis of Scientific Investigations. Marine Sanctuaries Conservation Series MSD-04-02. U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Marine Sanctuaries Division, Silver Spring, MD. 128 pp.


Starr, R.M, M.H. Carr, J. Caselle, J.A. Estes, C. Syms, D.A. VenTresca, and M. M. Yoklavich. 2004. A review of the ecological effectiveness of subtidal marine reserves in central California, Part II: Summary of existing marine reserves in central California and their potential benefits. Marine Sanctuaries Conservation Series MSD-04-03. U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Marine Sanctuaries Division, Silver Spring, MD. 13 pp.

Most evidence for the effects of marine reserves comes from tropical nearshore ecosystems. We attempted to evaluate the effects of marine reserves on temperate kelp forest systems by contrasting the population structure (density and size distribution) of 10 species of epibenthic fishes and several aspects of the associated ecosystems between three marine reserves and adjacent exploited areas in Central California. Densities of fishes were 12-35% greater within the reserves but this difference was not statistically significant. Habitat features explained only 4% of the variation in fish density and did not vary consistently between reserves and nonreserves.

The average length of rockfish (genus Sebastes) was significantly greater in 2 of the 3 reserve sites, as was the proportion of larger fish. Population density and size differences combined to produce substantially greater biomass and therefore reproductive potential per unit of area within the reserves. The magnitude of these effects seems to be influenced by the reserve's age. While our results demonstrate that current levels of fishing pressure influence kelp forest rockfish populations, differences between the reserves and adjacent non-reserves are surprisingly small. We discuss a number of reasons why the influences of fishing on kelp forest ecosystems may be greater, or at least different, than our findings indicate. Potentially confounding influences include the very small size of the reserves, effects of historical fishing, poaching, spillover effects on adult and larval populations from reserve to non-reserve habitats, and the possibility that catastrophic phase shifts induced by human disturbances have altered both reserve and non-reserve areas.

Stefansson, G. and A. A. Rosenberg. 2006. Designing marine protected areas for migrating fish stocks. Journal of Fish Biology. 69:66-78

This paper extends an earlier analysis and presents an investigation of how migration rates affect the performance of various types of management regimes with respect to economic yield and conservation benefits. Particular emphasis is placed on evaluating the geometric design of marine protected areas (MPAs). Earlier results have shown that MPAs are only likely to provide significant benefits when they are used in conjunction with direct catch or effort controls, unless they are quite large and cover most of the resource in question. Conversely, catch and effort controls are far more effective when protected areas are included in the management regime as a buffer against uncertainty. Dispersal of reproduction (recruitment) to other areas is an important expected benefit of protected areas, but such dispersal increases the variability of the effects of the area protection. If fishing mortality rates outside of the protected area are not controlled then dispersal can result in nullifying some of the benefits of the protected area. Similarly, adult migration increases the variability in the results when an area is protected and critically depends upon an overall control of fishing mortality outside the area. For both dispersal and migration separately or in combination, however, there are clear benefits to using MPAs in conjunction with catch or effort controls. These benefits are expressed in terms of long-term yield and recovery probabilities. In addition, short-term yield declines relatively slowly with increasing area protected. Design of the protected areas is seen to be important since using contiguous areas provide greater protection against overfishing than protected areas in isolation.

 Closed areas; effort control; fisheries management; managing under uncertainty; marine protected areas; quota systems

Stelzenmuller, V., F. Maynou, G. Bernard, G. Cadiou, M. Camilleri, R. Crec'hriou, G. Criquet, M. Dimech, O. Esparaza, R. Higgins, P. Lenfant and A. Perez-Ruzafa. 2008.Spatial assessment of fishing effort around European marine reserves: Implications for successful fisheries management. Marine Pollution Bulletin. 56:2018-2026.

We examined the spatial dynamic of artisanal fishing fleets around five European marine protected areas (MPAs) to derive general implications for the evaluation of MPAs as fisheries management tools. The coastal MPAs studied were located off France, Malta and Spain and presented a variety of spatial designs and processes of establishment. We developed a standardized methodology to define factors influencing effort allocation and to produce fishing effort maps by merging GIS with geostatistical modelling techniques. Results revealed that in most cases the factors 'distance to the no-take', 'water depth' and 'distance to the port' had a significant influence on effort allocation by the fishing fleets. Overall, we found local concentration of fishing effort around the MPA borders. Thus, neglecting the pattern of fishing effort distribution in evaluating MPA benefits, such as spillover of biomass, could hamper sound interpretation of MPAs as fisheries management tools.

Artisanal fishery; Fisheries benefits; Fisheries management; GAMs; Geostatistics; GIS; Regression kriging; Spatial modelling

Stelzenmuller, V., F. Maynou and P. Martin. 2009.Patterns of species and functional diversity around a coastal marine reserve: a fisheries perspective. Aquatic Conservation: Marine and Freshwater Ecosystems. 19:554-565.

  1. Marine protected areas (MPAs) are expected to function simultaneously as biological conservation and fisheries management tools, but empirical evidence linking biodiversity conservation with fisheries benefits is scarce. Around the Medes Islands marine reserve (Spain, NW Mediterranean) patterns of fish catch diversity, catch (CPUE) and income (IPUE) were assessed and the economic value of diversity for local fisheries was explored by combining a Geographic Information System (GIS) analysis with geostatistics.
  2. Catch data were derived from the trammel net fleet operating around the MPA to gain information on species diversity, functional diversity, functional redundancy, CPUE and IPUE.
  3. Results revealed significant impact of both the fishing prohibition in the MPA and the presence of seagrass beds on diversity metrics, catch and income. Clear differences in functional redundancy in fish assemblages were found within the study area, indicating greater resilience of the fish assemblage against fishing pressure or human impact close to the MPA (p2 km). In contrast, fish assemblages beyond 2 km of the MPA border are more vulnerable to disturbance. High values of diversity, CPUE and IPUE overlapped close to the MPA border and close to seagrass beds.
  4. The spatial approach developed suggests that, in addition to the more commonly studied effect of densitydependent spillover of adult fish, increased levels of ecological diversity and economic diversity can also result in fisheries benefits of an MPA. Hence, the fishing regulations in and around the Medes Islands marine reserve have shown that biological conservation and fisheries benefits can be complementary in the long-term, which should be considered in future policies for MPAs or MPA networks.

ecosystem function; fisheries enhancement; functional redundancy; GIS; spatial analysis; universal kriging

Stewart, G. B., I. M. Côté, M. J. Kaiser, B. S. Halpern, S. E. Lester, H. R. Bayliss, K. Mengersen, A. S. Pullin. (2008).Are marine protected areas effective tools for sustainable fisheries management? I. Biodiversity impact of marine reserves in temperate zones. Systematic Review, Centre for Evidence-Based Conservation: 1-33.

Marine Protected Areas (MPAs) have been proposed and designated as a mechanism to address the problem of achieving sustainable fisheries, while simultaneously preserving biodiversity. However, empirical studies and research syntheses indicate that there is considerable variation in the ecological effects of MPAs and there is considerable debate over whether they can produce fisheries benefits. Of the various types of MPAs, marine reserves (no-take areas) have been perhaps the best studied. Furthermore, by focusing on marine reserves, it is possible to eliminate protection level as a co-variate. Consequently, as a first review in a proposed series on the effectiveness of MPAs for sustainable fisheries management, we objectively collated data to ascertain the impacts of temperate zone no take areas on the density, biomass and species richness of marine biota within reserve borders (as reflected in the subtitle).

Marine protected areas, sustainable fisheries, biodiversity, no-take areas

Stobart, B., R. Warwick, C. Gonzalez, S. Mallol, D. Diaz, O. Renones and R. Goni. 2009. Long-term and spillover effects of a marine protected area on an exploited fish community. Marine Ecology Progress Series. 384:47-60.

We assessed the development of the exploited fish community inside and around the Columbretes Islands Marine Reserve (CIMR), a marine protected area (MPA), 8 to 16 yr after fishing ceased in the reserve. Sampling was by annual lobster trammel net fishing, an experimental technique used inside the CIMR, and on-board commercial operations in adjacent fishing grounds. We examined trends in combined fish abundance and biomass (catch per unit effort), species richness and diversity, size structure, trophic level and species composition of the community. Our results showed the CIMR fish community continued to change throughout the study period as (1) abundance and biomass increased, (2) mean body size and trophic level increased and (3) species composition changed according to a linear model. Relative to nearby fished areas the CIMR fish community had (1) higher abundance and biomass, (2) lower species diversity and higher taxonomic distinctness, (3) larger relative body size and (4) no difference in mean trophic level. We found clear evidence of spillover of fish from the CIMR to the adjacent fishery as commercial fish yields at the MPA border (<0.5 km from the boundary) increased continuously during the study period, despite being locally depleted due to fishing effort concentration (fishing the line). Furthermore, fish size and diversity at the border were intermediate between the CIMR and other fished zones, suggesting that this is a transitional zone influenced by this MPA. Our results show that changes in community abundance, biomass, size structure and species composition provide a clear and interpretable view of MPA recovery. Diversity indices are also useful; however, their interpretation is more difficult. We conclude that the creation of the CIMR has had a positive effect on the exploitable fish community and that there is evidence of exportation of biomass to the surrounding fishery. We highlight the advantage of using multiple community metrics to study changes in fish communities, yet recommend the need for caution when interpreting them.

Marine protected area; Fish community development; Spillover; Biomass; Diversity; Size spectra; Trophic level; Artisanal fishery; Mediterranean Sea

Stoms, D. M., F. W. Davis, S. J. Andelman, M. H. Carr, S. D. Gaines, B. S. Halpern, R. Hoenicke, S. G. Leibowitz, A. Leydecker, E. Madin, H. Tallis and R. R. Warner. 2005. Integrated coastal reserve planning: making the land-sea connection. Frontiers in Ecology and the Environment. 3:429-436.

Land use, watershed processes, and coastal biodiversity are often intricately linked, yet land-sea interactions are usually ignored when selecting terrestrial and marine reserves with existing models. Such oversight increases the risk that reserves will fail to achieve their conservation objectives. The conceptual model underlying existing reserve selection models presumes each site is a closed ecological system, unaffected by inputs from elsewhere. As a short-term objective, we recommend extending land-conservation analyses to account for effects on marine biodiversity by considering linkages between ecosystems. This level of integration seems feasible and directly relevant to agencies and conservancies engaged in protecting coastal lands. We propose an approach that evaluates terrestrial sites based on whether they benefit or harm marine species or habitats. We then consider a hypothetical example involving estuarine nurseries. Whether this approach will produce more effective terrestrial reserves remains to be seen.

Sumaila, U. R., S. Guenette, J. Alder and R. Chuenpagdee. 2000. Addressing ecosystem effects of fishing using marine protected areas. ICES Journal of Marine Science. 57:752-760.

This article is a synthesis of the current literature on the potential of marine protected areas (MPAs) a useful management tool for limiting the ecosystem effects of fishing, including biological and socio-economic aspects. There is sufficient evidence that fishing may negatively affect ecosystems. Modelling and case studies show that the establishment of MPAs, especially for overexploited populations, can mitigate ecosystem effects of fishing. Although quantitative ecosystem modelling techniques incorporating MPAs are in their infancy, their role in exploring scenarios is considered crucial.Success in implementing MPAs will depend on how well the biological concerns and the socio-economic needs of the fishing community can be reconciled.

Ecosystem effects of fishing; marine reserves; marine protected areas; community involvement; socio-economic

Taggart, S. J., J. Mondragon, A. Andrews, J. K. Nielsen. (2008). Spatial patterns and movements of red king and Tanner crabs: implications for the design of marine protected areas. Marine Ecology Progress Series 365: 151-163

Most examples of positive population responses to marine protected areas (MPAs) have been documented for tropical reef species with very small home ranges; the utility of MPAs for commercially harvested temperate species that have large movement patterns remains poorly tested. We measured the distribution and abundance of red king Paralithodes camtschaticus and Tanner Chionoecetes bairdi crabs inside and outside of MPAs in Glacier Bay National Park, Alaska, USA. By tagging a sub-sample of crabs with sonic tags, we estimated the movement of adult crabs from one of the MPAs (Muir Inlet) into the central portion of Glacier Bay where fishing still occurs. Tanner crabs and red king crabs moved similar average distances per day, although Tanner crabs had a higher transfer out of the Muir Inlet MPA into the central bay. Tanner crab movements were characterized by large variation among individual crabs, both in distance and direction traveled, while red king crabs migrated seasonally between 2 specific areas. Although Tanner crabs exhibited relatively large movements, distribution and abundance data suggest that they may be restricted at large spatial scales by habitat barriers. MPAs that are effective at protecting king and especially Tanner crab brood stock from fishing mortality will likely need to be larger than is typical of MPAs worldwide. However, by incorporating information on the seasonal movements of red king crabs and the location of habitat barriers for Tanner crabs, MPAs could likely be designed that would effectively protect adults from fishing mortality.

Marine protected area, MPA, Marine reserve, Sonic tracking, Transfer rate, Acoustic monitoring, Paralithodes camtschaticus, Chionoecetes bairdi

Tapia, F. J. and J. Pineda. 2007. Stage-specific distribution of barnacle larvae in nearshore waters: potential for limited dispersal and high mortality rates. Marine Ecology Progress Series. 342:177-190.

The stage-specific spatial distribution and mortality of Balanus glandula and Chthamalus spp. larvae were assessed with a series of daily vertical plankton tows collected from innershelf waters in La Jolla, Southern California, in March 2003. Sampling stations were located within 1.1 km of the shoreline, at depths of 10 to 45 m. For both groups, we observed a spatial segregation of naupliar stages and cyprids, although this pattern was statistically significant for Chthamalus spp. only. Early nauplii (NII and NIII) were more abundant at the inshore stations, whereas later stages (NIV to NVI) occurred in greater numbers offshore. Cyprids were consistently more abundant at the inshore station. Such striking differences in the horizontal distributions of late nauplii and cyprids suggest limited dispersal of barnacle larvae in nearshore waters. Particle trajectories computed from current velocities measured in the area indicated that changes in vertical distribution may indeed affect dispersal, and, in some cases, enhance the retention of larvae in shallow, inner-shelf waters. Vertical life tables were used to estimate naupliar mortality rates from pooled daily stage distributions. Average estimates (±SE) for the instantaneous rate of larval mortality in B. glandula (0.33 ± 0.05 larvae d-1) and Chthamalus spp. (0.23 ± 0.03 larvae d-1) were substantially higher than previously assumed for these species. We discuss the implications of limited dispersal and high mortality rates for the exchange of larvae among disjunct populations of intertidal barnacles and other coastal benthic invertebrates.

Larval distribution; Small scale; Balanus glandula; Chthamalus spp.; Dispersal; Mortality

Tetreault, I. and R. F. Ambrose. 2007. Temperate marine reserves enhance targeted but not untargeted fishes in multiple no-take reserves. Ecological Applications. 17:2251-2267.

Although many papers report the effects of no-take marine protected areas (MPAs or reserves), scientifically rigorous empirical studies are rare, particularly for temperate reef fishes. We evaluated the responses of fish populations to protection from fishing in reserves by comparing densities and sizes inside and outside of five no-take reserves in southern California, USA. Our results are robust because we compared responses across multiple rocky-reef reserves in two different years and controlled for possible site differences by (a) ensuring that habitat characteristics were the same inside and outside reserves, and (b) sampling species that are not targeted, which would not be expected to have a direct response to fishing. We compared fish density and size and calculated biomass and egg production across all five sites. Fishes targeted by recreational and/or commercial fisheries consistently exhibited increases in mean density (150%), size (30%), biomass (440%), and egg production (730%) inside reserves. Reserve effects were greatest for legal-sized targeted fishes: significantly greater densities were found exclusively inside reserves for targeted species (580%), the largest size classes existed only inside reserves, and mean biomass was 1000% higher. These responses were unlikely to have been caused by habitat differences because there were no significant differences in habitat characteristics between reserve and control locations. Densities of non-targeted species did not differ between reserve and non-reserve locations, further supporting the conclusions that differences in targeted species between reserve and control locations were due to harvesting rather than site-specific effects. Although MPAs cannot replace traditional fisheries management, the concentration of increased biomass and egg production is a unique MPA benefit that serves both reserves and fisheries. Scientifically rigorous studies that include multiple reserves, such as this study, are needed to inform management and policy decisions.

Topping, D. T., C. G. Lowe and J. E. Caselle. 2006. Site fidelity and seasonal movement patterns of adult California sheephead Semicossyphus pulcher (Labridae): an acoustic monitoring study. Marine Ecology Progress Series. 326:257-267.

The California sheephead Semicossyphus pulcher Ayres (Labridae) is a temperate, rocky-reef/kelp-bed fish that is sought by recreational and commercial fishermen. Long-term acoustic monitoring was used to ascertain site fidelity and seasonal movement patterns of S. pulcher. We implanted 16 adult (24 to 36 cm standard length) fish with long-term (~1 yr) acoustic transmitters and their presence and movement patterns were monitored in the Catalina Marine Science Center Marine Life Reserve using an acoustic receiver array. A method was developed that explained some of the variability in detection frequencies. A negative relationship between detection frequency and activity (rate of movement) was found for S. pulcher moving within the array. Most fish exhibited high site fidelity to the general area of the reserve, with 13 of the 16 fish detected spending an average of 99 ± 2% of their total days at liberty in the study area, with a mean of 90 ± 9% of total residence time spent within a 600 m core area. However, these fish showed some variability in area use between months, exhibiting periods of expansion in their range. Fish also tended to increase activity as seasonal water temperature increased. These expanded movements resulted in some fish crossing the reserve boundary for extended periods or leaving the reserve permanently.

Seasonal movements; Activity; Temperature; Marine reserve; Site fidelity; Residency; Acoustic telemetry; California sheephead

Topping, D. T., C. G. Lowe and J. E. Caselle. 2005. Home range and habitat utilization of adult California sheephead, Semicossyphus pulcher (Labridae), in a temperate no-take marine reserve. Marine Biology. 147:301-311.

The California sheephead, Semicossyphus pulcher Ayres (Labridae), is a carnivorous, temperate, rocky-reef/kelp-bed species that is highly sought in recreational and commercial fisheries. Fine-scale acoustic telemetry tracking was used to ascertain the home range and habitat utilization of S. pulcher. Sixteen adult S. pulcher (26–38 cm SL) were surgically fitted with small acoustic transmitters and manually tracked for up to 144 h during multiple, 24-h periods between March 2001 and August 2002 within the Catalina Marine Science Center Marine Life Reserve (33°26'N; 118°29'W). A geographic information system was used to calculate home range sizes (95% kernel utilization distributions) and habitat use. Tracking of the first five fish over 24 h confirmed that S. pulcher were strictly diurnal, so the remaining 11 fish were tracked from 1 h before sunrise to 1 h after sunset. Home ranges varied greatly, from 938 to 82,070 m2 with a mean (±SD) of 15,134±26,007 m2. Variability in home range sizes among fish was attributed to differences in habitat shape (embayment vs. contiguous coastline) and to natural habitat boundaries (deep, sandy expanses) in adjacent areas within the reserve. There was a significant relationship between fish length and proportion of time spent in different habitats (sand vs. reef). S. pulcher were found within rocky-reef areas 54% of the time, and, within these areas, a greater percentage of daytime was spent in high-relief areas. Based on the relatively small size and persistence of home ranges of adult S. pulcher, no-take reserves, if they contain appropriate habitat, would provide adequate protection for their stocks.

Tupper, M. 2007. Spillover of commercially valuable reef fishes from marine protected areas in Guam, Micronesia. Fishery Bulletin. 105:527-537.

Does adult spillover (movement out of marine protected areas [MPAs]) of fish create a net export of fish biomass from MPAs to adjacent fished reefs? Biomass of five commercial reef fish species was estimated by visual census within and outside three MPAs in Guam, Micronesia. For most species and sites, biomass was significantly higher within the MPAs than in adjacent fished sites. Movement of fishes into and out of the MPAs was determined by mark recapture experiments, in which fishes were tagged both inside and outside of MPAs. Four out of five species studied showed little or no net movement out of MPAs. However, the orangespine surgeonfish (Naso lituratus) showed a net spillover of biomass from all three MPAs; 21.5% of tagged individuals and 29% of the tagged biomass emigrated from MPAs. Patterns of spillover were strongly influenced by physical habitat barriers, such as channels, headlands, or other topographic features. MPAs that are physically connected by contiguous reef structures will likely provide more spillover to adjacent fished sites than those that are separated by habitat barriers. This study demonstrates that MPAs can enhance export of fish biomass to fished areas, but spillover is species-specific and depends on factors such as species size and mobility.

Tuya, F.C., M.L. Soboil, and J. Kido. 2000. An assessment of the effectiveness of Marine Protected Areas in the San Juan Islands, Washington, USA. ICES Journal of Marine Science 57: 1218-1226.

Marine protected areas (MPAs) can serve as effective sites for sheltering targeted populations. Furthermore, populations can experience increased abundance and body size in such areas. In this study we compared the abundance and body sizes of commonly collected fish and invertebrate species inside three marine preserves established eight years prior to our survey (University of Washington marine research preserves), two newly established MPAs, and three unprotected sites in the San Juan Archipelago. To determine whether population abundance and individual size were greater in protected areas within each site, these two parameters were measured for the red urchin (Strongylocentrotus franciscanus; Agasizz, 1865), sea cucumber (Parastichopus californicus; Stimpson, 1857), scallops (Chlamys rubida; Hinds, 1845; Chlamys behringiana; Midendorff, 1849; Hinnites giganteus; Gray, 1825), copper rockfish (Sebastes caurinus, Richardson, 1845), quillback rockfish (Sebastes maliger, Jordan & Jilbert, 1880), China rockfish (Sebastes nebulosus; Ayres, 1854) and lingcod (Ophiodon elongatus; Girard, 1854). The newly established MPAs and unprotected sites showed similar levels of abundance and size frequency distributions for the target species. Differences in abundance and size of small red urchins, scallops, rockfishes, and lingcod were not found among the three categories of sites, which could be attributable to a lack of effective protection within the protected sites. The UW marine preserves exhibited greater abundance of medium and large sized red urchins, which is explained because these areas lie within an urchin fishery closure zone established in the late 1970s. Ordination techniques showed that fishing pressure was the main cause of the decreased target populations assemblages. This study suggests that marine preserves have been effective in enhancing the medium and large size classes of the red urchin populations.

VenTresca, D.A. M.L. Gingras, J. Ugoretz, A. Voss, S. Blair, J. Plant, R. Hornady, C. Yoshiyama. 1997. The potential of marine reserves to enhance fisheries. Taking a Look at California's Ocean Resources: An Agenda for the Future, ASCE, Reston, VA (USA), vol.1: 400-411.

Rockfishes (Sebastes spp.) are an important and heavily exploited component of sport and commercial fisheries in central California, The success and quality of central California's nearshore rockfish sport fisheries have declined over the past decades, particularly in areas close to ports. Recognizing that a change in the current resource management approach is warranted, alternative management and enhancement strategies are of paramount importance. Our project, the Central California Marine Sport Fish Survey, has monitored nearshore recreational fisheries and documented life history characteristics of many rockfish species since 1956. Marine reserves have been reported to enhance fisheries in other parts of the nation and world, but limited information is available to evaluate their effectiveness relative to California's sport and commercial rockfish fisheries. The establishment of the Big Creek Ecological Reserve (BCER), approximately 50 miles south of Monterey, California, presents a unique opportunity to evaluate the effects of a reserve on the rockfish resource. Obtaining baseline information on species composition, densities, and length frequencies of rockfish populations within and adjacent to BCER is the crucial first step for determining change in population parameters and future benefits to adjacent and distant fisheries. This information will allow resource managers to evaluate marine reserves as an alternative management tool for rockfish populations. Present population parameters of selected fish populations in nearshore habitats within and adjacent to BCER have been assessed visually (densities) by scuba divers and recorded with an underwater video camera equipped with paired lasers (length frequencies) during permanent and random transects.

Vizzini, S. and A. Mazzola. (2009). Stable isotopes and trophic positions of littoral fishes from a Mediterranean marine protected area. Environ Biol Fish 84: 13-25.

Stable isotope analyses were employed to explore feeding and foraging habitats and trophic levels of littoral fishes in a western Mediterranean Marine Protected Area (Egadi Islands, Sicily, Italy). Carbon and nitrogen stable isotope ratios were measured in primary producers, invertebrates and fishes collected in December 2001 and January 2002. Fishes of the littoral region of the Egadi Islands had isotopic signatures that fell into a wider range for d13C (about 6‰) than for d15N (about 3‰). Carbon isotope ratios were consistent with a food web based on mixed sources and two trophic pathways leading to different fish species. Differences in the isotopic composition between islands were higher for benthivorous than for planktivorous fishes. The overall picture gained from this study is of a isotopic distinction between planktivorous and benthivorous fishes, resource partitioning facilitating the coexistence of similar species within the same ecosystem, and spatial variability in the isotopic signatures and trophic level of fishes. Asymmetrical analysis of variance showed that estimated trophic levels were lower in the area with the highest level of protection (Zone A) for only two out of the nine fishes analyzed. As a consequence, overall spatial differences do not seem to be a consequence of protection, since in most cases trophic levels did not change significantly between zone A and zones C where professional fishing (trawling apart) is permitted, but of natural sources of variation (e.g. variability in food availability and site specific food preferences of fishes). However, the results of this study suggest a different response at the species compared to the community level.

Stable isotopes, Trophic level, Food web, Spatial variability, Protection effects

Wallace, S. S. 1999. Evaluating effects of three forms of marine reserve on northern abalone populations in British Columbia, Canada. Conservation Biology. 13:882-887.

Marine reserves have been suggested as tools for assisting the management of fisheries by protecting vulnerable marine species from overexploitation. Although there is a theoretical basis for believing that marine reserves may serve as management tools, there are few marine reserves in the world in which to test their effectiveness. My research evaluated three forms of marine reserve on the south coast of Vancouver Island, British Columbia, Canada. I used northern abalone (Haliotis kamtschatkana), a severely depleted shellfish in this region, as an indicator of the effectiveness of the reserves. Abalone populations in eight sites receiving different degrees of spatial protection were counted and measured in situ during the spring of 1996 and 1997. In all sites with enforced harvest closures, populations of abalone were greater, and one site with nearly 40 years of protection had on average much larger (older) abalone. Reproductive output, as a function of abundance and size, was also greater in the enforced reserve areas. Larval dispersal from reserves, and hence the benefit to exploited areas, was not formally surveyed. Nevertheless, the results of my study, combined with knowledge of present abalone populations, life history, and regional hydrodynamics, suggest that establishment of reserves is justified in the absence of perfect knowledge of larval dispersal.

Walters, C., R. Hilborn and R. Parrish. 2007. An equilibrium model for predicting the efficacy of marine protected areas in coastal environments. Canadian Journal of Fisheries and Aquatic Sciences. 64:1009-1018.

Quantitative models of marine protected area proposals can be used to compare outcomes given current biological and economic knowledge. We used a model of a linear coastline, broken into 200 discrete cells each spanning 1.6 km of coast. This model is used to evaluate alternative proposals for marine protected area networks, predicting long-term (equilibrium) changes in abundances and harvests while accounting for dispersal of both larvae and older fish, changes in mean fecundity with reduced mortality in reserves, impacts of displaced fishing effort on abundances outside reserves, and compensatory (stock-recruitment) changes in post-settlement juvenile survival. The model demonstrates that even modest dispersal rates of older fish can substantially reduce the increase of abundance within protected areas compared to predictions from simpler models that ignore such dispersal. The strength of compensatory improvements in post-settlement juvenile survival is the most critical factor in determining whether a reserve network can rescue populations from the impacts of severe overharvesting. We use of the model to compare specific alternative proposals for protected area networks along the California coast, as mandated through California’s Marine Life Protection Act, and show that achieving the goals of the Act depends primarily on the fisheries management regulations outside of protected areas, and that the size and configuration of MPAs has a little impact.

Weible, C. M. (2008). Caught in a Maelstrom: Implementing California Marine Protected Areas. Coastal Management 36(4): 350-373.

The first attempt to implement the 1999 California Marine Life Protection Act (MLPA) to establish marine protected areas (MPAs) ended contentiously in 2002. The initial MLPA process is examined by a statutory analysis and an analysis of stakeholder network relationships and beliefs. The failure of the initial MLPA process can be understood by a combination of factors: (i) Insufficient financial support from the California State government; (ii) Unclear, unranked and inconsistent statutory objectives; (iii) The application of a science-based process that excluded affected stakeholders; (iv) Implementing officials who lacked expertise in designing and managing political processes; and (v) A community of stakeholders who were polarized into coalitions of proponents and opponents of MPAs. The article concludes by discussing limitations of its methods and analysis and by offering strategies for learning from policy failures.

coalitions, implementation, Marine Life Protection Act, marine protected areas, marine reserves

Weible, C. M. 2007. An advocacy coalition framework approach to stakeholder analysis: understanding the political context of California marine protected area policy. Journal of Public Administration Research and Theory. 17:95-117.

There is a growing recognition that public policy controversies are driven more by value differences than by technical deficiencies. Unfortunately, we have yet to develop, test, and refine systematic approaches for understanding political systems. In this article I explain how the advocacy coalition framework (ACF) can be used as a theoretical basis for understanding political context via a stakeholder analysis. An ACF stakeholder analysis widens the attention of policy analysts toward subsystem-wide dynamics with multiple actors who are motivated by their beliefs, structure their relationships into advocacy coalitions, and try to influence policy through utilizing multiple resources and venues. I illustrate an ACF approach to stakeholder analysis in a scientifically contentious political conflict over the establishment of marine protected areas in California. I conclude with a summary of contributions to the ACF literature and the strengths and limitations of conducting an ACF stakeholder analysis.

Weible, C. M. (2005). Beliefs and Perceived Influence in a Natural Resource Conflict: An Advocacy Coalition Approach to Policy Networks. Political Research Quarterly 58(3): 461-475.

To what extent do stakeholders in a conflict over natural resources interact with actors of congruent policy core beliefs or with actors who have perceived influence? The response to this question is structured principally by the Advocacy Coalition Framework (ACF) using questionnaire and interview data collected from stakeholders involved in California Marine Protected Area policy The findings indicate that shared beliefs are the best predictor for policy network relationships, supporting the ACE Perceived influence, while less important than shared beliefs, is another significant predictor.

Natural resource conflict, Advocacy Coalition Framework, marine protected area

Weible, C. M. and P. A. Sabatier. 2005. Comparing policy networks: Marine protected areas in California. The Policy Studies Journal. 33:181-201.

While most of the network literature focuses on information and advice networks, there is increasing interest-particularly among Advocacy Coalition Framework (ACF) scholars-on ally networks and coordination networks. This article asks two basic questions: First, do information, ally, and coordination networks overlap with each other? Second, and drawing from the ACF, do policy core beliefs structure the interactions in ally, coordination, and advice/information networks? We pursue these research questions in the context of the California Marine Life Protection Act process. We find that ally and coordination networks overlap slightly more than information/advice networks and that policy core beliefs do a better job of predicting ally and coordination networks than advice/information networks. Thus, we show that ally networks can provide a useful proxy for coordination networks to identify advocacy coalitions.

Advocacy Coalition Framework; Policy Networks; Marine Protected Areas

Weible, C., P. A. Sabatier and M. Lubell. 2004. A Comparison of a Collaborative and Top-Down Approach to the use of Science in Policy: Establishing Marine Protected Areas in California. Policy Studies Journal 32(2): 187.

The National Research Council has proposed two distinct approaches over the past 20 years for guiding decision making about risk. These two approaches are widely applicable to environmental decision-making and are exemplified by two attempts to establish Marine Protected Areas (MPAs) in California with the implementation of the 1999 Marine Life Protection Act. The first attempt, which parallels the NRC's 1983 linear scientific approach, was a top-down process that involved a Master Plan Team of scientists who created a proposal before gathering public input. The second attempt, which parallels the NRC's 1996 analytic and deliberative approach, involved a diverse set of stakeholders, including scientists, who worked in a collaborative process to provide a range of recommendations. We apply a three-tiered model of elite belief systems drawn from the Advocacy Coalition Framework to show that stakeholder preferences for either of these approaches is a function of their deep core beliefs. Stakeholders with strong preferences for scientific management support empirical claims for the benefits of MPAs and are more optimistic about the linear scientific approach compared to the analytic and deliberative approach for protecting major habitats, avoiding adverse fishing effects, and avoiding unfair agency domination. In contrast, stakeholders with pro-collaborative beliefs respect local knowledge and are more optimistic about the analytic and deliberative approach compared to the linear scientific approach for avoiding adverse fishing effects and unfair agency domination.

Wendt, D. E. and R. Starr. (2009). Collaborative Research: An Effective Way to Collect Data for Stock Assessments and Evaluate Marine Protected Areas in California. Marine and Coastal Fisheries: Dynamics, Management, and Ecosystem Science 1: 315-324.

Collaborative fisheries research (in contrast to cooperative research) is based on the intellectual partnership between scientists and fishermen and is an effective way to collect data for stock assessments and to evaluate marine protected areas. Collaborative fisheries research is discussed in the context of co-management of marine resources and how it contributes to a more democratic form of fisheries management. Many benefits result from working together, including (1) the incorporation of fishers' knowledge and expertise into the management process and (2) the development of shared perspectives derived through science-based investigations on the status of marine resources. The California Collaborative Fisheries Research Program was formed in 2006 to participate in the monitoring of marine reserves established through California's Marine Life Protection Act. This program has shown that it can serve as a model for other areas that are trying to implement collaborative research and that collaborative research can greatly contribute to the realization of community-based co-management of marine resources.

California marine life protection act, collaborative research, stock assessments

White, C., B. E. Kendall, S. D. Gaines, D. A. Siegel and C. Costello. 2008. Marine reserve effects on fishery profit. Ecology Letters. 11:370-379.

Some studies suggest that fishery yields can be higher with reserves than under conventional management. However, the economic performance of fisheries depends on economic profit, not fish yield. The predictions of higher yields with reserves rely on intensive fishing pressures between reserves; the exorbitant costs of harvesting lowdensity populations erode profits. We incorporated this effect into a bioeconomic model to evaluate the economic performance of reserve-based management. Our results indicate that reserves can still benefit fisheries, even those targeting species that are expensive to harvest. However, in contrast to studies focused on yield, only a moderate proportion of the coast in reserves (with moderate harvest pressures outside reserves) is required to maximize profit. Furthermore, reserve area and harvest intensity can be traded off with little impact on profits, allowing for management flexibility while still providing higher profit than attainable under conventional management.

Bioeconomics; density dependence; fishery profit; marine reserves; stock effect

White, C. and B. E. Kendall. 2007. A reassessment of equivalence in yield from marine reserves and traditional fisheries management. Oikos. 116:2039-2043.

Lively debate continues over whether marine reserves can lead to increased fishery yields when compared to conventional, quota-based management, apparently driven by differences in the complexity and biological richness of the models being used. In an influential article, Hastings and Botsford used an analytically tractable, spatially implicit, non-age-structured model to assert that reserves are typically incapable of increasing yields relative to conventional management, regardless of the type (pre- or post-dispersal, involving adults and/or larvae) or functional form (Ricker or Beverton-Holt) of density dependence present. A recent numerical (simulation) model by Gaylord et al. concludes that reserves can enhance yield compared to conventional management, a result the authors attribute to their spatially-explicit evaluation of stage-structured adult growth, survivability and fecundity; and intercohort (adult-on-larvae) post-dispersal density dependent population dynamics. Here we demonstrate that the increased model complexity is not responsible for the different conclusions. We analyze a spatially-implicit model without stage structure that incorporates intercohort postdispersal density dependence. In this simple model we still find annual extirpation of adult populations outside reserves due to fishing to enhance larval recruitment there, allowing for increased yields compared to those achieved when harvest is evenly spread across the entire domain under conventional management. Consideration of neither spatially-explicit dispersal dynamics nor stage-structure in adult demographics is required for reserves to substantially improve yield beyond that attainable under conventional management. In contrast, consideration of within cohort post-dispersal density dependence among larva during settlement in an otherwise identical model generates equivalence in yield between the two management strategies. These results recast a common message characterizing the relative benefit of reserve versus non-reserve management from "equivalence at best" to "potentially improved".

White, J. W., L. W. Botsford, A. Hastings, J. L. Largier. (2010). Population persistence in marine reserve networks: incorporating spatial heterogeneities in larval dispersal. Marine Ecologty Progress Series 398: 49-67.

The relationship between marine reserve design and metapopulation persistence has been analyzed only for cases of spatially homogenous advective-diffusive larval dispersal. However, many coastlines exhibit more complex circulation, such as retention zones in which slower-moving currents shorten dispersal distances and larvae can accumulate. We constructed metapopulation models that incorporated 3 types of spatial variability in dispersal associated with retention zones: (A) reduction of both advective (LA) and stochastic (LS) length scales of dispersal within the retention zone, (B) reduction of LA only, and (C) accumulation of larvae in the retention zone, followed by redistribution along the coastline. For each scenario, we examined reserve networks with a range of size and spacing configurations. The scenarios differed in the relative number of self-persistent reserves, i.e. those which can survive in isolation, and network-persistent reserves, i.e. those which rely on connectivity through space and across generations to offset shortfalls in direct self-replenishment. When dispersal was dominated by stochastic movements (LS > LA in scenarios A and B), metapopulations typically consisted of self-persistent reserves. As dispersal became increasingly advective (LA > LS), retention aided persistence, and network persistence became more prevalent. Persistence in scenario C decreased with the amount of redistribution. The specific patterns of persistence depended on the size and number of reserves and demographic parameters, but self-persistence was always more likely for reserves in the retention zone. Thus, placing a reserve in a retention zone to promote population persistence is advisable for all 3 dispersal scenarios.

Larval dispersal, Dispersal kernel, Headland, Metapopulation, Marine reserve, Persistence, Self-recruitment

Willis, T. J., R. B. Millar and R. C. Babcock 2003. Protection of exploited fish in temperate regions: high density and biomass of snapper Pagrus auratus (Sparidae) in northern New Zealand marine reserves. Journal of Applied Ecology. 40:214-227.

  1. The use of marine reserves as tools either for conservation or fisheries management requires rigorous empirical evidence for the recovery of exploited species within them.
  2. The relative density and size structure of snapper Pagrus auratus (Sparidae), an intensively exploited reef fish species, were measured, using baited underwater video, inside and outside three northern New Zealand marine reserves (Leigh Marine Reserve, Hahei Marine Reserve and Tawharanui Marine Park) every 6 months from October 1997 to April 1999.
  3. Log-linear modelling showed that relative total density and egg production of snapper were higher in all three reserves than in fished areas. Snapper that were larger than the minimum legal size were estimated to be 14 times denser in protected areas than in fished areas, and the relative egg production was estimated to be 18 times higher. In the Leigh reserve, legal-size snapper were larger than legal-size snapper in fished areas.
  4. At the Leigh reserve, snapper density consistently peaked at the reserve centre and declined towards either boundary, which suggests that snapper became increasingly vulnerable to fishing towards the reserve boundaries.
  5. Inshore snapper density was significantly higher in autumn than in spring, supporting previous suggestions that snapper make regular inshore-offshore seasonal migrations that might be related to spawning. We suggest that the observed recovery of snapper populations within reserves is attributable to immigration of individuals from fished areas that take up residency within reserves, rather than juvenile recruitment.
  6. Synthesis and applications. This study demonstrates the effectiveness of marine reserves for protecting an exploited species previously thought to be too mobile to respond to area-based protection. Although it is difficult to envisage significant enhancement of fished areas via adult emigration, it is likely that the reserves contribute significantly to local gamete production. In addition, the protection of fish populations within reserves might slow reductions in genetic diversity caused by size-selective mortality brought about by exploitation.

baited underwater video; fishing; migration; no-take; recovery; replication

Willis, T.J., R.B. Millar, R.C. Babcock, and N. Tolimieri. 2003. Comment - Burdens of evidence and the benefits of marine reserves: putting Descartes before des horse? Environmental Conservation 30(2): 97-103.

An extensive literature has appeared since 1990 on the study of 'no-take' marine reserves and their potential to make significant contributions to the conservation and management of fisheries, especially in tropical environments (see Polunin 1990; Roberts & Polunin 1991; DeMartini 1993; Roberts 1997; Allison et al. 1998; Guenette et al. 1998). The literature describes many potential benefits of marine reserves to fisheries, including increases in spawner-biomass-per-recruit and increases in larval supply from protecting 'source' populations ( Jennings 2000). The important word here is 'potential'. Some claims made by advocates of marine reserves might be regarded as optimistic, whereas critics of reserves might sometimes have been unduly harsh. Conservation goals for marine reserves are often poorly defined, and differences of opinion regarding the efficacy of reserves for fulfilling any of their stated goals can frequently be attributed to a lack of good information with which to predict their effects. Here, we critically examine the literature from 1990-2001 to determine (1) the relative effort put into empirical and theoretical approaches to predict reserve effects, and (2) the quality of empirical evidence available to support theoretical predictions. It is not the purpose of this article to single out particular studies for criticism (although this is sometimes inevitable to provide examples), nor to draw conclusions concerning the efficacy of marine reserves.

Our purpose is to examine the science, rather than politics, of the field of 'marine reserves'. We examined the relevant peer-reviewed primary literature from 1990-2001 by searching the Current Contents and Science Citation Index (ISI) databases using the keywords 'marine reserve' found anywhere in a paper. Also included were papers that were not in the search databases but were cited in papers that were (these included refereed proceedings of symposia, but excluded book chapters and unpublished reports). Only studies that directly investigated the effects of reserves were included. Many articles that explored specific biological issues mentioned marine reserves incidentally in the discussion. These were removed from the analysis, as were those concerned solely with policy, management or advocacy. The remaining papers (n _ 205) were classified into three groups, namely empirical (presenting field data from existing reserves), theoretical (conceptual or numerical modeling studies) and review (including notes and ideas papers based on other literature). With few exceptions, empirical papers reported some positive impact of the marine reserve or reserves under study, so these were carefully examined to determine (1) the robustness of the survey design, and (2) the effect size.

Yoklavich, M. M., H. G. Greene, G. M. Cailliet, D. E. Sullivan, R. N. Lea and M. S. Love. 2000. Habitat associations of deep-water rockfishes in a submarine canyon: an example of a natural refuge. Fishery Bulletin. 98:625-641.

A multidisciplinary assessment of benthic rockfishes (genus Sebastes) and associated habitats in deep water was conducted in Soquel Submarine Canyon, Monterey Bay, California. Rock habitats at depths to 300 m were identified by using bathymetric and side-scan sonar imaging, verified by visual observations from a manned submersible, mapped and quantified. Species composition, abundance, size, and habitat specificity of fishes were determined by using a video camera and parallel laser system along transects made by a submersible.

We counted 6208 non-schooling fishes representing at least 52 species from 83 10-min strip transects that covered an estimated 33,754 m2. Rockfishes represented 77% of the total number of individuals, and included a minimum of 24 species. Six distinct habitat guilds of fishes were manifest from habitat-based clustering analysis: small species were associated with mud and cobble substrata of low relief, and larger species of rockfishes were associated with high relief structures such as vertical rock walls, ridges, and boulder fields. There was remarkable concordance between some of the guilds identified in Soquel Canyon and the results of other habitat-specific assessments of fishes along the west coast of the United States from central California to Alaska. These generalities are valuable in predicting community structure and evaluating changes to that structure, as well as in applying small-scale species-habitat relationships to broader-scale fishery resource surveys. Additionally, establishment of these groups is critical when incorporating the concept of essential fish habitat (EFH), and negative impacts to it, into the management of fisheries in relatively deep water, as required by the Sustainable Fisheries Act of 1996. High numbers of large rockfishes (e.g. Sebastes chlorostictus, S. levis, S. rosenbblatti, and S. ruberrimus) were locally associated with rock ledges, caves, and overhangs at sites having little or no evidence of fishing activity. Abundance and size of several species were lower at fished than at unfished sites. We suggest that rock outcrops of high relief interspersed with mud in deep water of narrow submarine canyons are less accessible to fishing activities and thereby can provide natural refuge for economically important fishes, as exemplified in Soquel Canyon.

Yorio, P. (2009). Marine protected areas, spatial scales, and governance: implications for the conservation of breeding seabirds. Conservation Letters XX: 1-8.

As in many regions worldwide, seabird colonies in Argentina are important conservation targets of marine protected areas (MPAs). Seabirds are wide ranging, often crossing jurisdictional boundaries during foraging. Using a recently designated MPA as a case study, this article discusses the challenges of protecting breeding seabirds given their spatial requirements and use of different jurisdictions. Seabirds breeding at the MPA have distinct foraging strategies. Rock Shags and Olrog's Gulls forage inshore within the MPA. Imperial Cormorants, Magellanic Penguins, and Southern Giant Petrels, in contrast, often feed beyond the MPA's jurisdiction, traveling into provincial, federal, or international waters where they can be affected by fisheries and oil development. This indicates the need of management actions beyond MPA boundaries. The large scale and connectivity of marine ecosystems and the variety of economic pressures require the participation of stakeholders and several government agencies in conservation issues, and thus integrated coastal management and marine spatial planning appear as options to complement the use of MPAs. Although MPAs are a valuable tool to conserve breeding seabirds, increased efforts are needed to design new governance structures and complementary strategies for spatial protection so as to deal with the biological, social, and political complexities of marine systems.

Breeding seabirds; conservation tools; fisheries; foraging seabirds; governance; marine protected areas; Patagonia; spatial scales

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