Concerns for the north coast abalone fishery include:
- Small numbers of young abalone
- Indications of depletion at heavily used sites
- Increase in legal abalone take
CDFW scuba surveys have revealed few abalone in the 2-5 inch size range, an indication that significant reproduction has not occurred. At Van Damme State Park in the early 1990's scuba surveys found that over 75% of the population was under the legal size compared to only 50% today. Surveys at Fort Ross, Salt Point, and two reserve sites (Bodega and Cabrillo) show a similar lack of small abalone. Surveys have shown no significant reproductive events in red abalone in more than a decade. Even if large numbers of young abalone were to appear this year, the growth rate of north coast red abalone is so slow that they will not grow to legal size for ten years or more.
Data from abalone creel surveys show significant increases in travel distance for shore pickers at some sites. This means that areas nearest to access points are depleted and fishermen must travel farther to take abalone. Creel data also show declines in catch-per-unit effort for some Sonoma and southern Mendocino County sites.
Mendocino and Sonoma Counties now account for 96% of the sport abalone effort. The estimated take for these counties increased 27% in the past decade.
Poaching is a problem but wardens estimate all forms of illegal take are only 12% of the legal take. The legal take is considerably larger than the illegal take.
These concerns lead biologists to believe that a precautionary approach to the management of red abalone should be taken to conserve red abalone resources.
Abalone are easily overfished. They have slow growth, infrequent reproductive success, vulnerability to fishery-related injuries, high mortality of small animals, and need high densities for successful reproduction. These factors limit the ability of abalone to withstand a fishery. An abalone fishery could take decades to recover from collapse. Great care will be needed to prevent the northern California red abalone fishery from joining all the abalone fisheries which have collapsed worldwide.
There have been reports of numerous empty shells of undersized abalone at popular fishing sites. Although there are many possible causes of death for undersized abalone, a likely cause is carelessness in picking and returning undersized abalone.
Ab irons are designed to reduce the chances of injuring abalone, but the irons can still cause fatal wounds if used improperly. Foot cuts deeper than inch are likely to cause death since abalone have no blood clotting capabilities. Cuts around the head are often fatal. When sliding an iron under an abalone, keep the iron as close to the rock as possible to avoid stabbing the foot. In prying abalone off rocks it is important that the ab iron handle be lifted away from the rock so that the tip of the bar does not dig into the bottom of the foot.
Even uninjured abalone could easily be killed by predators if they are not carefully returned to suitable habitat. Abalone put on sandy areas or seaweed covered rock surfaces will not be able to clamp down sufficiently to protect themselves from predators. Fishing regulations require an undersized abalone be returned to the same surface of the rock from which it was detached. Experienced abalone pickers can distinguish undersized abalone and do not remove them from rocks. Avoiding removal of undersized abalone helps protect abalone populations since any time an abalone is removed from a rock, there is a chance that it could be fatally injured or unable to reattach to a safe location.
Abalone punch cards must be returned to CDFW. These cards provide valuable information for understanding the fishery. Past efforts in estimating total annual take of abalone were conducted by telephone surveys with limited sample sizes. Since punch card data have a much larger sample size, estimates made from these data will be more accurate and precise.
The 2000 estimates were derived from about 1000 abalone punch cards randomly sampled from over 10,000 cards: the average number of days fished was 5.1, average number of abalone taken per day was 3.6, and average annual take was 18.5 abalone. More than half of the sampled cards showed 12 abalone or fewer. Approximately 25% of the fishermen took 30 or more abalone, less than 8% took more than 50 abalone and less than 0.4% took 100 abalone. June had the highest number of days of fishing followed by May and April. Effort for abalone drops off sharply after August with only 11% of the total catch taken in October and November.
The estimated total take from punch cards was 728,000 abalone over 202,000 days of fishing; this number represents over 2 million pounds of abalone which is too high to be sustainable. These levels of catch are similar to the take of red abalone in the southern California commercial fishery in the 1960's before the fishery started to decline. Since the southern California abalone fishery could not sustain this level of take, it is likely the northern California recreational fishery would not be able to sustain this level either. Red abalone in northern California are believed to grow slower and reproduce less frequently than those in the south; these population characteristics make northern red abalone even more vulnerable to overfishing than southern red abalones. To protect this valuable fishery, cautious management measures need to be taken. It is important to begin to protect abalone populations in early stages of overfishing since they recover very slowly.