Recent accomplishments of CDFW's scientific community
Beneath the waters off the California coast are vast forests that are home to an astounding variety of animals. Their sunlit canopies can soar 150 feet from the ocean’s floor. But instead of trees, these forests are made of kelp.
Worldwide, kelp is used in a host of everyday products like toothpaste, pudding, ice cream and even pharmaceuticals. Although kelp is valuable to humans, it is critical to sustaining life for many ocean-dwelling wildlife species ranging from microscopic plankton to sea otters, pelagic birds and predatory fishes. When a kelp forest is depleted, the entire underwater ecosystem can be thrown out of balance. This is why CDFW scientists are tracking and studying the amount of kelp growing in coastal waters.
In 1989, CDFW marine biologists began using aerial surveys to monitor the size of the kelp forests off of California’s coast. A second survey was conducted a decade later, and since 2002, CDFW has made an effort to conduct these surveys annually (although budget issues sometimes require skipping a year).
The surveys are conducted along the entire coastline and offshore of the Channel Islands. CDFW conducted the earliest surveys on its own, but now contracts out for this work. The contractor uses an aircraft with a specialized camera system that picks up the infrared image of the kelp. Those images become Geographic Information System (GIS) shapefiles that capture a snapshot of what the kelp canopy looks like on a given day. The images enable the viewer to see and compare the spatial area of a specific kelp forest over time.
A graph depicting CDFW’s historic aerial kelp survey data is located on the Kelp and Other Marine Algae webpage.
CDFW’s most recent (2016) kelp survey includes the following findings:
Rebecca Flores Miller, a marine environmental scientist with CDFW’s Marine Region office in Monterey, was the coordinator for the 2016 kelp survey.
“Kelp does fluctuate normally, anyway … there is a seasonality with it,” she explains. “However, during El Nino and warm water conditions as we’ve had in the recent past, the canopy doesn’t grow as well.”
Coastal development can also negatively affect the kelp canopy, as it sometimes leads to pollution, increased turbidity (which reduces the light needed for photosynthesis) and siltation (which can hinder growth or bury young kelp). An increase in urchin populations can also have a dramatic impact on kelp, and recently, a wasting disease decreased the numbers of sea stars (a predator of urchins) statewide.
“All of these things are connected within the ecosystem,” Flores Miller says.
Kelp survey data is available to anyone who is interested – members of the general public, other governmental agencies, universities and researchers.
The dataset has many uses, both within and outside of CDFW. It is used during the review process for commercial kelp bed lease requests. It has been a critical piece of the Marine Protected Area planning process. It has been used to help predict the abundance of many kelp forest-dependent species valued by humans, such as abalone. And it has helped scientists understand issues such as the recent abalone die-off in northern California.
CDFW Photos: giant kelp and bull kelp (by Rebecca Flores Miller), and image of kelp forest near Cambria taken during the 2016 aerial kelp survey.
Fate has not been kind to the San Joaquin kit fox (Vulpes macrotis mutica).
Shrinking habitat caused by urbanization and agricultural expansion landed this Central Valley native on the federal Endangered Species List decades ago. California’s total population of San Joaquin kit foxes may now be down to a few thousand animals. To make matters worse, its favorite food, the kangaroo rat, is likewise endangered as the desert habitat it prefers continues to disappear.
Wildlife biologists took heart, however, in a population that seemed to be thriving within the city limits of Bakersfield. Unlike San Joaquin kit fox populations in other parts of the Central Valley range, the Bakersfield foxes adapted quite nicely to urban life. Their number – estimated between 200 and 400 animals – has evidently seemed to be holding steady and possibly increasing.
Their cute and cuddly appearance make them popular with city residents. Earlier research showed the population was healthy and genetically robust. Wildlife biologists were counting on those urban foxes to ensure the species’ survival should kit fox populations completely collapse elsewhere.
Today, those Bakersfield kit foxes are under siege, suffering from an outbreak of highly infectious sarcoptic mange. Mange – a skin condition caused by parasitic mites -- leads to hair loss, open wounds from scratching and, ultimately, death. The first case was detected among the kit fox population in March 2013, and since then, more than 200 cases have been documented. The epidemic has grown worse every year.
Given the importance of the Bakersfield population, CDFW, the U.S. Fish and Wildlife Service, the California State University, Stanislaus, the University of California, Davis (UCD), and various nonprofit wildlife groups have all joined forces to combat the mange.
Jaime Rudd, an environmental scientist in CDFW’s Wildlife Investigations Lab in Sacramento, is leading CDFW’s efforts while simultaneously writing her UCD Ph.D. dissertation on the outbreak. Rudd is researching ways to prevent mange from spreading to healthy animals, and assisting Stanislaus State’s Endangered Species Recovery Program with trapping and treating diseased foxes.
Severely diseased kit foxes are trapped and transported to the California Living Museum, a Bakersfield wildlife rehabilitation facility and zoo. There, the kit foxes are hospitalized, given life-saving antibiotics and fluids and treated with a topical pet product that kills the mites. The foxes often need months of treatment before they are healthy enough to release. And although the intervention saves individual lives, the process is costly and time-consuming – and doesn’t prevent the treated fox from getting mange a second or third time.
Rudd is making good use of her undergraduate degree in molecular biology, analyzing the DNA of the mites to see if they might be related to those in dogs and coyotes, which could be spreading the mange to the foxes.
“Essentially, we want to look at their molecular signature to see if these mites are related,” Rudd said.
Rudd is studying a group of wild kit foxes living on the CSU Bakersfield campus, which no doubt are supplementing their diet with burger bits and pizza crusts discarded by college students. Rudd is monitoring the group with trail cameras, outfitting some foxes with radio tracking collars and others with the type of preventative flea and tick collar you might use on a pet dog or cat.
“We want to evaluate the efficacy of these collars,” she said. “If they’re only going to work for two months, the collars won’t help us slow down the spread of mange, so is it really worth the effort of putting them on? But if they’re going to work for five months or more, then it might be worth the effort.”
If there is any hope sustaining Rudd and her colleagues in this important, though often disheartening, work, it’s this: “The fact we are not seeing mange in the outlying populations is cause for optimism,” she said. “If nothing else, we can at least try to keep it from leaving the city.”
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