Domoic Acid Poisoning

Sea Lions Rescued from Domoic Acid Poisoning

By Peter Wallerstein

Peter Wallerstein of MAR testing the responsiveness of a California sea lion. Photo: Jonathan Alcorn

LOS ANGELES COUNTY In the spring of 2002 a crisis fell upon hundreds, if not thousands, of pregnant California sea lions, dolphins and pelicans along the Pacific coast of the United States. Domoic acid, a naturally occurring marine biotoxin, produced by marine diatoms which are members of the genus Pseudo-nitzschia, forced pregnant sea lions to beach themselves suffering major seizures, foaming from their mouths, the whites of their eyes bloody red and many of the sea lions, paralyzed from the toxin had blood excreting from their nipples.

The sea lions were completely disoriented from the neurotoxin. Dozens of Common dolphins and pelicans also suffered from attacks on their brains and nervous systems by the rapid reproduction of the toxic single-cell plankton. The Marine Mammal Care Center at Fort MacArthur in San Pedro, California accepts mammals for rehabilitation from Los Angeles County and parts of Orange and Ventura Counties. The Center’s staff and volunteers did an excellent job during the domoic crisis, but Fort MacArthur was overloaded for weeks which prompted the National Marine Fisheries Service (NMFS) to enact a 48 hour monitoring period before an animal may be rescued. Only “non-responsive” animals could be assisted before the 48 hour period expired. NMFS policy caused members of Marine Animal Rescue (MAR) to have to triage dozens of sea lions daily leaving them unassisted on the beach.

Peter Wallerstein of MAR hoop netting an adult female sea lion suffering from domoic acid poisoning. Photo: Steve McCrank/Daily Breeze

It was very difficult to leave a suffering animal on the beach that we would normally rescue immediately. From 7 o’clock in the morning to 10 o’clock at night we located the animals, gave each of them multiple evaluations throughout the day, rescued as many of the animals as possible and evaluated the new ones that arrived daily. The MAR hotline was receiving over 60 calls a day. We would receive calls at 2 o’clock in the morning from irate citizens wanting to know why we weren’t helping the animal they were calling us about. But most citizens after hearing what was truly going on, understood and were sympathetic. Some citizens even assisted  with the safer parts of our rescues.

Almost all of the sea lions suffering from the domoic acid would arrive at the beach very hyperactive. The first day they would stay at shores edge, up on the fore flippers, rocking their heads back and forth, over and over again. After 24 hours, many much sooner, the sea lions were forced to their bellies, paralyzed by the toxin. When the domoic crisis began we observed some of the victims having seizures in the surf, looking as if they would not make it to the beach alive. We began pulling some of the sea lions from the surf to a safe place on the beach. Although very dangerous, this would at least give them another chance.

As the numbers increased, we couldn’t possibly pull all the sea lions from the surf, we had to observe and hope for the best. We did see that the vast majority made it to the beach on their own. Others swam off, only to attempt beaching somewhere else. More than once we were called to assist a domoic sea lion that had gotten stuck, deep into a rock jetty. The poor sea lions couldn’t move in any direction and at the same time they were suffering from seizures. In one incident, County Lifeguard, Dave Estey, a citizen and myself worked for close to an hour, using cargo straps, shovels and our hands and feet to finally free and then rescue the suffering sea lion.

In April, some of the sea lions began birthing their pups prematurely. Some were stillborn, others alive. We were advised that at this point the pups lungs were so under developed that they wouldn’t survive no matter what anyone did. We decided to keep those pups with their moms for the few hours they had to live. It was heartbreaking. We did observe that many of the pregnant sea lions that gave birth prematurely, were gaining strength and returning to the water with added vigor on their own.

The mis-education people receive from captive display facilities was very obvious during this crisis. A sea lion beached on a busy day in Venice, California and was quickly surrounded by 200 people trying to pet the frightened and distressed sea lion. I am amazed that more people weren’t bitten. Luckily for the citizens the domoic caused most of the sea lions to be very incoherent to their surroundings. We saw people attempting to bounce balls off a sea lions nose or take family photos next to the suffering and unpredictable sea lions. Other well intentioned, but misguided citizens tried to pull the sea lions back into the water not knowing how dangerous this could be and also that their actions might cause death to the sea lion. Some people would even hold the head of a sea lion while it was suffering a seizure. One out of ten sea lions awoke from their seizures looking for something to attack. In one incident, in Venice Beach, a women got too close to a sea lion as it awoke from a seizure. She got bit severely and the sea lion, up on all fours charged at anything near it. It was very sad to see these normally non-aggressive animals act so violently and out of control. They were scared and sick. The sea lion charged the Lifeguards upon their arrival and also charged MAR volunteers when we arrived. Due to her aggressiveness and her location we received permission to rescue her. With assistance from County Lifeguards we rescued the sea lion and brought her in for treatment at Fort McArthur.

Sea lion suffering from domoic acid. Watch this rescue and more in the MAR "Making the Difference" Promo Video on the Home Page.

With the Federal policies, the public safety issues and the enormous number of stranding it took the cooperative efforts of many agencies that allowed MAR to successfully  rescue over 100 animals, including 68, 200 plus pound sea lions and dolphins. We triaged hundreds of other animals. The City of Los Angeles Animal Control was very supportive, backing MAR up by handling many of the pelican calls. Special thanks to the Los Angeles County Animal Control along with some other Animal Control agencies like Manhattan and Redondo Beach for their support and cooperation. Thanks to the Police and Fire Departments throughout the County who cooperated and assisted MAR during the domoic crisis. Special acknowledgment and thanks must go to the Los Angeles County Lifeguards. Their professionalism, physical conditioning, cooperation and their participation in just about every MAR rescue allowed MAR volunteers to assist as many of the suffering animals as we did.

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Video footage of sea lions suffering from domoic acid poisoning.

The official numbers provided by the Federal government are considerably lower than the actual numbers. Many  dead sea lions are still washing on shore daily. We all agree that the suffering was intense. Fifty percent of the domoic cases we rescued have a chance for survival and have another chance to give birth again. No one knows to what level the sea lion population has suffered from the domoic Acid. Considering the numbers we saw on our local beaches it is a great concern of ours. Domoic acid effected much of the Pacific coast. The rookeries on the Channel Islands of the coast of California must be strewn with dead bodies. Why did this toxic bloom happen so early in the year? Domoic blooms are usually seen in the summer months, after the pupping season. The bloom seemed to single out pregnant California sea lions who still had a couple of months to go before the pupping season and male Common dolphins. All of the sea lions MAR rescued or triaged were pregnant. We do know the domoic acid caused lesions on the brains of the animals. But, with so little experience with these kind of cases, much needs to be learned about the long term effect domoic acid will have on the survivors.

During the El Niño season of 1997-98 we saw hundreds of pups starve to death due to the lack of available food and a place to care for all of them. We’ve seen and rescued many animals suffering from gill net entanglement and gun shot wounds. But, in 20 years of Southern California rescue experience, I have never seen anything on our local beaches that compares to the horrific and heartbreaking suffering caused by the toxic algae bloom in the spring of 2002.

MAR volunteers gave each and every animal our very best efforts.

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