Since April, Marine Animal Rescue has rescued 33 sea lions suffering from domoic acid poisoning in L.A. County, according to the group’s incident reports. Last year, the organization rescued none.
Peter Wallerstein, Director of Marine Animal Rescue, said this is the first time he’s seen sea lions with domoic acid poisoning in five years.
“The fish eat the Pseudo-nitzschia (algae) and the sea lions eat the fish and the neurotoxins in their bodies affects their brains and it really does all kinds of damage to them,” Wallerstein said.
Wallerstein said in years past the period in which he found sea lions and others suffering from domoic acid poisoning lasted about a month.
About 24 percent of the sea lions Marine Animal Rescue has rescued were found on Hermosa Beach, Redondo Beach or Manhattan Beach. Many of the sea lions with domoic acid poisoning are pregnant females.
The domoic acid, produced by the algae Pseudo-nitzschia, can cause neurological problems, like seizures and paralysis, in sea lions and other animals, according to Clarrissa Anderson, executive director of the Southern California Coastal Ocean Observing Systems at Scripps Institution of Oceanography.
“It mimics important amino acids that we need, sea lions need them, any vertebrate needs them. It then acts as a toxic neurotransmitter by kind of falsely binding to those same transmitters that your amino acids would. You end up with a pretty bad neurotoxic effect,” Anderson said.
The memory center of the brain, the hippocampus, gets degraded and destroyed over time when animals are exposed to the toxins, Anderson said. Though there are some things that can be done to lessen the effects of the domoic acid poisoning, there is no cure. As a result, once an animal has been stranded from domoic acid poisoning, its chances of becoming stranded in the future is higher.
Wallerstein attributes the increase in the number of sea lions suffering from domoic acid poisoning to the abnormal amount of rain L.A. County saw this past winter.
“It’s from pesticides and fertilizers and stuff that gets washed into the ocean when it rains and that feeds the bloom. So it makes it bloom much more intense and a lot bigger,” Wallerstein said.
Anderson said she would be hesitant to link the recent rain to the increase in sea lions suffering domoic acid poisoning.
“It’s been hard to show that link between runoff and increase in pseudo nietzsche algal bloom,” Anderson said.
Nonetheless, Anderson said she would not separate human activity from the increase in the algal blooms.
“We do know society is shaping harmful algal blooms. We are having an effect. We are seeing more of them. We are seeing bigger ones, more toxic ones all the time all over the entire world,” Anderson said. “Even if there is no smoking gun in this particular bloom, we know that a lot of our activity is shaping the course of the trends that we are seeing.”