Pollution contributing to marine mammal deaths

Investigators say water pollution is contributing to a spate of marine mammal deaths that have scattered carcasses along the California coast.

In the past several weeks, dozens of whales, dolphins and sea lions have washed ashore dead or dying from Los Angeles’ Venice area to San Luis Obispo.

The latest discovery occurred Tuesday in Ventura, where an 8-foot juvenile minke whale washed up dead at San Buenaventura State Beach. Lifeguards buried it in the sand.

“It is episodic. Springtime is peak time when this happens,” said Michelle Berman, assistant curator and marine mammal specialist for the Santa Barbara Museum of Natural History. “Animals are reproducing, and we have upwelling and nutrients that can lead to red tides. But to have so many in a short time frame is not so common.”

In Santa Barbara, a 29-foot sperm whale washed ashore April 9 near Isla Vista. In both instances involving whales, investigators collected tissue samples from the carcasses in an effort to pinpoint the cause of death.

Meanwhile, numerous dolphins and sea lions are washing ashore sick or dead on Southland beaches.

Peter Wallerstein, president and founder of Whale Rescue Team in Los Angeles, said he has conducted 78 marine mammal rescues this year, many of them common dolphins. He rescued a dolphin at Santa Monica beach and another at Venice beach this week. A live harbor porpoise washed up near Oceano Dunes near San Luis Obispo but died later.

Joe Cordaro, wildlife biologist for the National Marine Fisheries Service, said he does not see an ecological disaster under way but is concerned about toxic algae. It can produce domoic acid, which accumulates in shellfish and fish and sickens seabirds, otters, sea lions, dolphins, whales and humans. He said some sea lions show symptoms of domoic acid poisoning, including seizures and paralysis, but he said investigations are under way to determine if other factors contribute to the problem.

“We get spurts like this from time to time,” Cordaro said, “but whenever we get one like this, this many (fatalities) at one time, it raises our antennae.”

Officials warn beach-goers to keep themselves and children a safe distance from animals that appear distressed, especially sea lions.