Southland Sea Lions Succumbing to Toxin

At least 22 sick or dead sea lions stricken by a debilitating toxin have washed up on Southern California beaches in recent weeks, raising fears that the poison could kill hundreds more this summer.

Three dead sea lions believed to have ingested the substance were discovered in San Pedro on Monday morning, one at Cabrillo Beach and two at White Point, rescue workers said. Late Monday afternoon, a sick, pregnant female lion washed up on Venice Beach.

On Sunday, four of the ailing mammals -- at least one of them pregnant -- were rescued from Dockweiler State Beach near Playa del Rey, Venice Beach, Santa Monica State Beach and Will Rogers State Beach, and taken to a marine care center in San Pedro for treatment. At least three other sick sea lions were found recently on some of the same beaches.

In Orange County, the toxin has been detected in at least 11 pregnant sea lions in Huntington Beach and Newport Beach in recent weeks, and all succumbed to illness, said Michele Hunter, director of animal care at the Pacific Marine Mammal Center in Laguna Beach.

“It’s put a tremendous strain on us,” said Hunter, whose center treated some of the sea lions. “It’s hard for the volunteers and very disheartening to see these sea lions have seizures, because it’s not just affecting one life, it’s affecting two. They are such beautiful, intelligent, graceful animals.”

The sea lions were poisoned by domoic acid, which is produced by a naturally occurring algae. Sardines, anchovies, clams, mussels and other marine life feed on the algae and are in turn eaten by sea lions, dolphins and seabirds such as pelicans. Passed on in this way, the toxin can cause a neurological disorder resulting in seizures, disorientation, loss of muscle coordination and death.

The disorder’s toll on sea lions and other wildlife in Southern California waters has increased since 2002, and scientists are not sure why. That year, more than 1,100 sea lions from Santa Barbara to San Diego were sickened by the toxin, and 600 died.

In 2003 and again in 2004, 75 to 100 sea lions washed up on Los Angeles, Ventura and Orange County beaches, said Peter Wallerstein, director of the Whale Rescue Team in Playa del Rey, which cares for sick marine animals.

In previous years, state health officials have alerted the public to avoid eating certain small fish and shellfish that may be contaminated.

“Before 2002 we saw very few of these cases in Southern California,” Wallerstein said, adding that global warming may be intensifying production of algae blooms, or they may be fed by pollutants such as nitrate runoff from agriculture.

“I’m alarmed because this could seriously impact the California sea lion population,” he said. “I think we’ve had the first red flag this week.”

Rescue workers are especially concerned because the appearance of the algae in late spring and early summer is having the most serious effect on pregnant sea lions, which normally give birth and mate in the summer.

The females seem more susceptible than males because of feeding patterns: They are likely to eat more of the algae-tainted fish while pregnant, said David Bard, operations director of the Marine Mammal Care Center at Ft. MacArthur in San Pedro, which is tending seven stricken sea lions. Many animals survive with treatment, he said.

“The key thing is to keep them hydrated and nutritionally stable while they’re coming out of this,” said Bard. “We can also administer anticonvulsants. If the toxin doesn’t stay in the system, there is a chance. But if there is long-term tissue damage in the brain, it can turn into a chronic condition.”

Hunter said several of the sea lions rescued in Orange County died en route to the center before they could be treated. Two of the 11 sea lions gave birth to stillborn cubs. A couple of others had aborted in the wild.

The others were carrying dead fetuses. One sea lion with signs of the poisoning was also found to have cancer of the uterus and was euthanized, Hunter said.

Rescue workers and animal control officers stressed that people should not try to help sea lions that beach themselves because the sick animals can bite and transmit other diseases. Under the federal Marine Mammal Protection Act, it is illegal to touch or disturb a marine animal, and violators face a $10,000 fine and up to a year in jail, said Chris Linkletter, a captain with the Los Angeles County Lifeguards.

“People can go to the nearest open lifeguard station or contact a beach maintenance crew,” Linkletter said. “We can actually evaluate the animal to determine if it’s in distress and call the proper authorities.”