Toxic Algal Bloom Makes Sea Lions Go Aggressive, Attacking Los Angeles Beachgoers

Aggressive sea lions that had been sick from domoic acid poisoning bit some beachgoers in Los Angeles.

A few beachgoers in Los Angeles were bitten by aggressive sea lions that had been sick and suffering from the effects of domoic acid poisoning.

Aggressive Biting Sick Sea Lions

Experts on marine wildlife claimed that a poisonous algal bloom in Southern California that is infecting hundreds of sea lions is causing the animals to act abnormally, including being aggressive and even attacking beachgoers.

Domoic acid, which is toxic and can be lethal to marine life, is released by the aforementioned bloom. According to Marina Mammal Care Center CEO John Warner, the number of reports of sea lion bites at LA beaches increased as it moved down the coast through San Luis Obispo past Los Angeles County.

According to Warner, the center has received over 20 reports of aggressive sea lions biting swimmers at LA beaches in the last three to four weeks.

According to Warner, the conduct is wildly unusual for sea lions. Although no scientific study has explicitly stated that this is connected to domoic acid, it would be logical to assume that the two are connected.

Domoic acid, which damages a sea lion's brain and alters its behavior and capacity to respond to its environment, has been causing sick sea lions to wash up on coasts for almost two weeks now, Patch reports.

Domoic Acid Poisoning in Sea Lions

Pseudo-nitzschia australis is a form of algae that produces domoic acid during specific harmful algal bloom occurrences. Small fish, such as sardines and anchovies, build up this neurotoxin, which sea lions subsequently consume in enormous amounts.

Domoic acid causes seizures and heart failure by attacking the heart and brain. It typically results in permanent brain damage if untreated. The toxin will eventually naturally leave an animal's system, but sea lions who are repeatedly exposed to it will experience more severe and long-lasting symptoms, according to The Marine Mammal Center.

Domoic acid also kills sea lions and other animals and causes vomiting, strange behavior, seizures, pregnancy loss, and death. The rise in sea lion incidents could be a sign that other marine animals are coming under more and more threat.

In cases where domoic acid is not present, strandings and symptoms still appear, indicating that past exposure may have had negative effects on one's health. Wildlife vets and staff can better grasp the handling risks that may arise with these violent animals during rehabilitation by recognizing unnaturally aggressive behaviors as an indication of domoic acid poisoning. Affected animals can then receive the most appropriate diagnosis and treatment, according to National Centers for Coastal Ocean Science NCCOS.

In the Works

NCCOS is investigating the connection involving aggression and seizure behavior in laboratory rats subjected to the toxin domoic acid as part of an ongoing investigation to determine the source of domoic poisoning and better understand the symptoms California sea lions experience as a result of the toxin. According to their findings, seizures or not, heightened aggression can be a sign of domoic acid overdose. However, the aggression is not long-lasting.

Their continued research will give decision-makers a scientific foundation on which to base the best rehabilitation strategies. Their work is described in detail on the NCCOS website.