Toxic algae bloom killing dolphins and other marine animals along Southern California coast, experts say

LOS ANGELES — Dozens of marine animals, including an unprecedented number of dolphins, are dying due to a toxic algae bloom now stretching from San Diego to San Luis Obispo. The entire shoreline is an extreme danger zone due to a neurotoxin called domoic acid or DA.

This is the fourth year in a row that this has happened, and experts say this is the worst yet.

A map from the Southern California Coastal Ocean Observing System shows the high amount of domoic acid at the center of the toxic algae bloom now engulfing the Southern California coast and killing numerous animals.

“It’s the worst we’ve ever seen here in Southern California on many different fronts, but dolphin strandings, it’s unprecedented,” said John Warner, the CEO of the Marine Mammal Care Center in Los Angeles.

In the past week, there have been more than 50 dead and dying dolphins found along the L.A. County coast. There were 16 in San Diego on Sunday alone.

“It’s really been consistently severe, the number of animals coming up on the beaches, either with seizures or dead or dying, has continued at a pretty high rate,” said Michael Milstein with NOAA Fisheries, West Coast Region.

Sea lions are traditionally the main victims of a toxic algae bloom, which can cause them to turn aggressive and attack beachgoers. But now, the toxic algae bloom is moving further up the food chain.

READ MORE: Aggressive sea lion caught on video at Newport Beach euthanized after chasing surfers

Shocking video shows an aggressive sea lion actively going after people in the water and on shore. Experts say a toxic algae bloom in the water is making marine mammals sick and changing their behavior.

Researchers say a minke whale found in the Port of Long Beach and a young gray whale in Huntington Beach both died due to domoic acid toxicity.

“It is a natural phenomenon that happens because of offshore winds, cold water upwelling, but it can be fed and sort of put on steroids by the things we’re doing,” Warner said.

Debris from the wildfires and fertilizer runoff are helping to fuel the toxic algae, which are eaten by small fish, which are then eaten by marine mammals and birds, causing a potentially deadly toxic overdose.

While sea lions and birds can be saved, it is 100% fatal for dolphins.

As researchers are sounding the alarm, they are also holding hope that the beloved animals won’t suffer any long-term damage.

“We know these populations are resilient, strong and can bounce back from this relatively quickly, provided they have the food and other resources they need,” Millstein said.

At this point, experts say they see little hope for immediate relief given how widespread and well-fed the algae bloom is.

Copyright © 2025 KABC Television, LLC. All rights reserved.

You May Also Like

'Jeopardy!' champion Caleb Groen from Thousand Oaks, California tops $300,000 after 10 wins

Jeopardy! Champion Caleb Groen of Thousand Oaks Surpasses $300,000 With 10th Win

LOS ANGELES — Caleb Groen, a Thousand Oaks, California, native, has become…
Foreclosure filings surged 21% this year. Here are the states where they are rising fastest.

Foreclosure Filings Jump 21%: States Seeing Biggest Spikes

Foreclosure activity climbed sharply across the United States in the first half…
Shameless NYC Council members give themselves a big fat 18% pay hike -- on first day on the job

NYC Council Members Vote Themselves 18% Pay Raise on Day One

They made a lot of noise over their own paychecks. City Council…
NFL employee injured in Midtown tower shooting sues NYC for $24M

NFL Employee Wounded in Midtown Tower Shooting Files $24M Lawsuit Against NYC

An NFL employee wounded in last year’s deadly Midtown Manhattan office tower…
Gurnee Woodland Elementary School teacher Todd Fowler charged with disseminating child pornography, Lake County Sheriff says

Coast Guard Joins Mayday Search Near Indiana Dunes Park

PORTER, Ind. () — A search on Lake Michigan was called off…
A new chapter for America’s 250th: 'J250' initiative puts Jewish contributions in the spotlight

J250 Puts Jewish Contributions at Heart of America’s 250th

DOJ launches 15-city antisemitism awareness tour amid rising hate crimes As antisemitic…
Family of grandmother who was killed falling into open NYC manhole files wrongful death suit against ConEd

Family of Grandmother Killed in Open NYC Manhole Fall Files Wrongful Death Lawsuit Against Con Edison

The grieving family of a grandmother who died after falling into a…
Lucas Bradshaw's family sues Amazon, others after driver Shawn Akison crashes into school bus in LaPorte County, Indiana in 2025

Lucas Bradshaw’s Family Sues Amazon Over Indiana School Bus Crash

LAPORTE COUNTY, Ind. () — The family of a teenage baseball player…
Mikie Sherrill ripped after NJ skips flag directive honoring Lindsey Graham: ‘Most political governor’

Mikie Sherrill Faces Criticism After New Jersey Skips Flag Directive Honoring Lindsey Graham

New Jersey Gov. Mikie Sherrill is facing criticism after state flag-status records…
Baltimore beat-down: Video shows group of teens pummeling elderly man outside 7-Eleven as police hunt suspects

Police Seek Teens After Baltimore 7-Eleven Elderly Man Beating

Baltimore police are asking for the public’s help identifying a group of…
Trump zeroes in on election security. His team has cut thousands of election-focused federal workers.

Trump Focuses on Election Security as Team Cuts Thousands of Federal Election Workers

Election security has remained a defining focus for President Trump for years.…
NYC subway shove victim recounts terrifying attack by unhinged stranger

NYC Subway Shove Victim Recounts Terrifying Attack by Stranger

It is the kind of subway horror story New Yorkers fear most.…