A sick sea lion is pictured at the Marine Mammal Care Center in San Pedro, California, on July 6, 2023.
Los Angeles, California – Thousands of marine mammals along the Southern California coast have fallen ill or died this year due to a severe harmful algae bloom, according to marine life experts and federal officials.
The bloom, first detected in February, has been linked to the deaths of several species, including sea lions, dolphins, and whales. The National Oceanic and Atmospheric Administration (NOAA) Fisheries West Coast confirmed in a news release that four whales — one humpback, one minke, and two gray whales — have washed ashore dead in Orange and Los Angeles counties in recent weeks.
NOAA determined that domoic acid, a neurotoxin produced by the algae, was the cause of death for two of the whales: a juvenile female humpback whale stranded in Huntington Beach and a juvenile male minke whale found in the Port of Long Beach.
“This is consistent with the many other marine mammals we have seen affected by domoic acid produced by the harmful algal bloom off Southern California,” said Michael Milstein, spokesperson for NOAA’s West Coast regional office, in a statement to the Los Angeles Times.
Domoic acid accumulates in small fish such as sardines and anchovies, which are then eaten by larger predators. The toxin moves up the food chain, ultimately affecting marine mammals who feed on contaminated fish.
NOAA noted this is the fourth consecutive year Southern California has experienced domoic acid outbreaks, with the current bloom being the most severe to date. Experts believe rising ocean temperatures are contributing to the frequency and intensity of these harmful algae blooms.
The agency is urging members of the public to report any sightings of stranded marine mammals to the West Coast Marine Mammal Stranding Network by calling 866-767-6114.
As the blooms continue, marine scientists and wildlife responders are monitoring coastal areas closely and warning beachgoers to stay away from distressed or deceased animals.
