VENTURA COUNTY, Calif. — A new count shows southern sea otters making a tepid comeback along the coast of California, and experts say more work needs to happen to protect the furry mammals.
Working with other agencies, the U.S. Geological Survey has counted the sea otter population each spring since the 1980s. Federal and state wildlife agencies use the information to help manage the threatened species and aid its recovery, officials said.
“We’re pleased to see a reversal in the negative trend that happened in the last few years,” said Tim Tinker, a research biologist with the USGS Western Ecological Research Center.
But overall, the population seems to have reached a plateau, he said.
This year’s count started in April and spanned from San Mateo County to the edge of Ventura County at Rincon Point. The survey found 2,865 otters and pups this year, bringing the three-year average to 2,792. That’s slightly up from the three-year average of 2,711 in 2010.
The 2011 survey wasn’t completed due to weather conditions, officials said.
The number of California sea otters significantly increased in the mid-2000s and exceeded 2,800 in 2007. The population started dropping three years ago.
Some areas along the coast are showing increases while others have stayed stable or declined slightly, said Tinker, also an adjunct professor at the University of California, Santa Cruz. Work is ongoing to better understand what’s causing those differences, he said.
Threats to sea otters continue to include infections and boat strikes. This year, officials found an increase in the number of lethal shark bite wounds.
“That’s one of the causes of death we’re investigating right now,” Tinker said. The so-called tasting bites may happen because sharks mistake the otters for similar-size seals and move on when they get a mouthful of fur instead of blubber.
Little can be done about natural factors affecting the sea otters, but the Fish and Wildlife Service says the marine mammal’s recovery likely depends on the population’s expansion into new areas.
A no-otter zone was established in 1987 as part of the recovery program to protect the marine mammals, keeping them away from fishermen after the same food otters eat.
Otters were relocated to San Nicolas Island off the Ventura County coast with the hopes they would establish a population there. Any animals found south of Point Conception -- the no-otter zone -- would be captured and moved to the island or back north.
But most of the otters swam away, and the program was abandoned in 1993.
The federal agency, however, did not officially end the plan at the time. That process is ongoing and likely will be completed by the end of the year.
(Contact Cheri Carlson of the Ventura County Star in California at ccarlsonvcstar.com