After hundreds of sea lions and dolphins washed up dead on Southern California beaches, experts are pointing to a toxic algae as the likely cause.

Over the course of one week (June 8-June 14), the Channel Islands Marine Life Institute in Santa Barbara received thousands of reports regarding sick and dead marine animals along California’s southern beaches, the National Oceanic and Atmospheric Administration (NOAA) stated in a press release.

“It’s been really sad,” Michelle Berman Kowalewski, a biologist and the director of the Channel Islands Cetacean Research Unit, told The New York Times.

California rescuers have been inundated with calls about sick and dying sea lions and dolphins along the state’s central coast. They believe the cause is a toxin produced by a harmful algae. https://t.co/I95cyxhDM9

— The New York Times (@nytimes) June 21, 2023

While conservation groups are awaiting test results to verify the cause behind the slew of dead and dying animals, experts have pointed to the rapid growth of toxic algae, known as Pseudo-nitzschia, as the likely cause, the outlet stated. The algae produces a neurotoxin known as domoic acid which can lead to seizures, brain damage and death, according to the NOAA.

The neurological symptoms displayed by the affected sick animals found along the shorelines combined with readings showing high concentrations of domoic acid along the southern coast of California, particularly around Santa Barbara and Ventura counties, support their assessment. (RELATED: Blob Of Seaweed Twice As Wide As The US Bears Down On Florida, Researchers Say)

“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,” Kowalewski stated, according to NOAA.

While domoic acid poses a threat to marine life, humans are only affected if they consume contaminated food items. The rise of toxic algae along California’s shores prompted the California Department of Public Health to issue a warning earlier in June against eating mussels, clams, or scallops harvested from the area.