Sea lions are dying in record numbers from Chile to Oregon and the Marine Mammal Center in Marin County has seen the number of stranded and dead sea lion pups in the Bay Area hit a number not seen since 1998.
And the deaths have hit home.
An adult sea lion was rescued last week at Coyote Point in San Mateo and Pacifica has also seen a large number of stranded sea lion pups wash up on its beaches.
In 1998, the Marine Mammal Center responded to just less than 1,200 stranded sea lions. This year, by mid-July, the center had already exceeded that number, said Dr. Bill Van Bonn of the Marine Mammal Center.
"We have already attended to more than 1,300 stranded or dead sea lions," Van Bonn said. The center's mission is to rehabilitate the pups and send them back out into the ocean.
The center has exceeded capacity for most of the year.
The deaths could be attributed to a warming ocean, or El Nino event, as was the case in 1998, said Dr. Bill Van Bonn of the Marine Mammal Center.
"It's not likely any kind of new virus or disease," Van Bonn said.
The deaths and strandings are more likely due to adult sea lions being forced to search farther out to sea to find food, leaving pups closer to shore, eventually starved and dehydrated.
"The pups are no longer nursing when the adults leave but are unable to make the long trips to find food," Van Bonn said.
Van Bonn was in Oregon a month ago where sea lions are being stranded at a similar rate. At least 200 sea lions have been found dead along Chile's northern coast last week.
Environmental groups said Saturday they suspect a local molybdenum plant may be to blame for the deaths in the Southern Hemisphere. Peru also reported earlier this month that more than 20 sea lions had been found dead in the Chimbote region there.
Controversy erupted recently in Oregon when it was suspected six sea lions were gunned down at Bonneville Dam. The sea lions feed on salmon and compete with commercial fisherman and puncture wounds suggested the sea lions were shot while trapped inside floating cages.
Federal fisheries officials said they do not know how the animals died, however.
Examinations found no gunshot wounds and determined the neck wounds were probably caused by bites from another sea lion.
Sea lions have had robust numbers in recent years, however, Van Bonn said, and that strandings and deaths are fairly typical.
"The difference this year is the numbers," he said. "There are far more strandings this year than in previous years."
The Marine Mammal Center deals with stranded sea lions and other animals from 600 miles of coast and relies on more than 800 volunteers to rescue the animals.
An algal bloom, or red tide, took place in Half Moon Bay last week. Red tide is an event that algae accumulate rapidly in the water.
Some red tides are associated with the production of natural toxins, depletion of dissolved oxygen or other harmful effects. The worst effects of red tides are the associated wildlife deaths among marine and coastal species of fish, birds, marine mammals and other organisms.
The Marine Mammal Center sends data to the National Oceanic and Atmospheric Administration and will start sitting down with the numbers soon, said Van Bonn, who has worked with marine mammals for more than 26 years.
Bill Silverfarb can be reached by e-mail: firstname.lastname@example.org or by phone: (650) 344-5200 ext. 106.