A spate of recent shark attacks has devastated already diminished numbers of sea otters along the California coastline.
Scientists recorded 19 cases of shark bite wounds to sea otters in August, compared to a 10-year average of seven. In recent weeks, The Associated Students Coastal Fund teamed up with the Defenders of Wildlife — a national, nonprofit organization dedicated to the protection of native animals and plants — to organize the eighth annual Sea Otter Awareness Week.
The Coastal Fund also awarded the organization a grant with the stipulation that the group hire two UCSB students to help with the annual project.
Even though researchers aren’t certain why attacks have increased in the past few months, some scientists and marine researchers attribute the phenomenon to the greater number of juvenile sharks lining California’s coast. The young predators often mistakenly bite the otters as they transition from preying on fish to larger creatures such as seals and sea lions.
Although shark bites are usually accidental or exploratory, Michael Harris, an environmental scientist for the California Department of Fish and Game, said such wounds nevertheless prove to be fatal for otters as they tend to have fragile bodies.
“White sharks do not typically feed on sea otters,” Harris said. “Their preferred prey is seals and sea lions. This would explain why the majority of the otters collected have a single bite mark. These bites are more investigative — like a taste test.”
This summer’s relatively cool temperatures are also likely to have tempted the sharks into previously uncharted waters.
Aside from predator attacks, Tim Tinker, a research wildlife biologist for the U.S. Geological Survey Western Ecological Research Center, said other factors have led to the sea otter population decline.
“Our data suggest that breeding-age females are dying in higher-than-usual numbers from multiple causes, including infectious disease, toxin-exposure, heart failure, malnutrition and shark attacks,” Tinker said.
Tinker also said human activities and natural causes such as use of toxic fertilizers and detergents, oil leaks, over-fishing, by-catching and climate change have threatened America’s sea otter communities.
With the population falling 3.6 percent for a second consecutive year, widespread disease and the recent influx of freshwater toxins into the otters’ saline habitat have also had a detrimental effect.
Jim Curland, a marine program associate for Defenders of Wildlife, said the organization encourages communities to be aware of the consequences that their actions have on marine ecosystems.
“Our belief is that to inform the public about the plight of a particular species is to engage them,” Curland said. “If we are to save any species, it has to come from public involvement, education and a change in behavior.”