More California sea lions dying

Recent deaths of 14 mammals are linked to domoic acid.

During an average year, rescue workers at the Pacific Marine Mammal Center in Laguna Beach may encounter one pregnant sea lion suffering from domoic acid poisoning — a potentially deadly illness that occurs when the animals eat fish that have been feeding on toxic algae.

In the last two weeks, the center has recorded 14 sea lion deaths attributed to domoic acid poisoning.

“Other rescue facilities are also seeing the same animals,” center spokeswoman Krysta Higuchi said. They’re “all over the place.”

In 2007, the last time the problem was this severe in Southern California, 79 sea lions died from domoic acid poisoning despite efforts by the center to rescue them, Higuchi said.

State officials have issued warnings against eating mussels, clams or whole scallops harvested recreationally in Santa Barbara County.

“Dangerous levels of domoic acid have been detected in mussels from this region, making them unsafe to consume,” the California Department of Health said in an April 13 release.

When domoic acid poisoning occurs in humans, it’s called “amnesic shellfish poisoning.” No cases have been reported in California.

Higuchi said 25 poisoned sea lions were rescued in just the last two weeks, and it was unclear how many would survive. Two of them have been released and two more have started eating again, which raises hopes, she said. Staff are injecting the remaining animals with fluids to “flush those toxins” before it affects their brains.

The acid comes from the growth of tiny single-celled algae that usually bloom for about a week during the spring. These blooms can be intensified by heavy rains that flush nutrients from fertilizers and other sources into the Pacific Ocean.

Small sea animals such as clams, mussels and anchovies feed on the algae, and then they are in turn eaten by sea lions.

“When the sea lions eat these toxic anchovies, they have serious neurological problems,” said Kathi Lefebvre, a research biologist at the National Oceanic and Atmospheric Administration Fisheries in Seattle. “The sea lions will have seizures, in some cases they’ll die, in some cases they’ll recover but have permanent brain damage.”

For the most part, humans are safe, Lefebvre said, though regulatory agencies will issue warnings if there is a danger.