Toxic Algae Sickness Spreads Among California Marine Wildlife

A group of seals seen in Isla de Lobos, an island off the coast of Punta del Este, 140 km east of the Uruguayan capital, Montevideo, 10 August 2005. Pablo Porciuncula/AFP via Getty Images

According to the National Oceanic and Atmospheric Administration, hundreds of Dolphins and other marine mammals along the Southern California coast have gotten sick or died this month due to toxic algae bloom.

The rapid growth of the algae Pseudo-nitzschia causes the production of a neurotoxin called domoic acid, which leads to animal strandings as the toxin is transferred into the marine food web.

Marine mammals like sea lions and dolphins ingest the toxin when they eat affected prey.

The Channel Islands Marine & Wildlife Institute (CIMWI) has fielded more than 1,000 reports of sick and dead marine mammals from June 8 through June 14, said Ruth Dover, co-founder and managing director.

CIMWI is part of the West Coast Marine Mammal Stranding Network, coordinated by NOAA Fisheries, and responds to live marine mammal strandings in Ventura and Santa Barbara Counties.

The front entrance to Marine Mammal Center in the Marin Headlands in Sausalito, Calif., on September 10, 2012. Canticle/WikipediaCommons

“We are managing more than 200 reports of marine mammals in distress daily,” Dover said. “We are doing our best to keep up with the intense pace. Please continue to report all sick and injured marine mammals as we get to as many animals as possible, as quickly as we can, each day.”

On Tuesday, June 13, CIMWI staff and volunteers managed more than 200 reports of distressed animals, including nine live dolphins and 25 sick sea lions. “We are doing the best we can to keep up with this intense pace,” CIMWI said in an Instagram post on Wednesday, which showed television coverage of volunteer efforts.

Forecasts provided by NOAA CoastWatch and the Southern California Coastal Ocean Observing System show high concentrations of domoic acid from Orange County north to San Luis Obispo County.

“I have never seen anything this intense in terms of the numbers of animals in my 20 years of responding to strandings in this area,” said Michelle Berman Kowalewski, founder and director of the Channel Islands Cetacean Research Unit.

She said many of the dolphins had been stranded alive and then died. Several of the dolphins and many of the sea lions were pregnant females.

Algae usually bloom between March and June in California, but may be peaking later this year because of a long and rainy winter.

The blooms can pose a danger to humans as well. People can become sick if they consume fish packed with the toxins, though the California Department of Public Health monitors these levels and closes shellfish beaches when necessary, David Caron, a biological sciences professor at the University of Southern California, said.

Humans may also attempt to approach larger mammals like sea lions and dolphins if they see them stranded on the beach, but the animals may become aggressive because of the toxins.

Dr. Caron said that people should avoid marine creatures and call rescue organizations, which have saved some animals by capturing them, feeding them, and giving them liquids until they can flush the toxins out of their systems.

At the Pacific Marine Mammal Center in Laguna Beach, the staff mostly treats females who have just given birth and are lactating, the OC Register reported.

“If we can get the girls out of their intoxicated state, we might release them earlier in hopes that they can find their pups again,” Dr. Alissa Deming told the OC Register. “Sea lions are very good mothers and sometimes take another pup and raise it. We’d like them to have a chance to get back out to the islands again.”

Tests of tissue samples collected from the affected animals may help understand how the toxin spreads and whether other factors, such as illness, may be involved.

“We are trying to learn as much as we can as fast as possible,” Kowalewski said. “As difficult as it is to see these animals die, we want to gather information to help understand how and why this is happening the way it is.”