California Sea Lions Falling Ill From Algal Bloom Toxin
California sea lions are becoming sick and washing ashore along the coast due to poisoning from domoic acid, a toxin produced by algal blooms. The Marine Mammal Center in Sausalito has treated over 100 affected sea lions, with a significant…
San Francisco Oakland San Jose, CA, September 2, 2026 —
California sea lions are experiencing a surge in illness and appearing stranded along the state’s coastline, primarily due to poisoning by domoic acid. This neurotoxin is produced by certain types of marine algae that form harmful algal blooms.
The Marine Mammal Center, based in Sausalito, has reported treating more than 100 sea lions affected by the domoic acid poisoning. Officials noted a significant increase in these cases beginning in July.
The affected animals have been observed along a wide stretch of the coast, with a notable concentration of cases reported in the counties of Monterey, Santa Cruz, San Mateo, San Francisco, Marin, and Sonoma.
Sea lions exhibiting symptoms of domoic acid poisoning often display lethargy, disorientation, and seizures. These neurological effects can be severe and are characteristic of the toxin’s impact.
Contributing environmental factors have been identified, including warm ocean temperatures and broader climate change patterns, which are believed to play a role in the proliferation of the algal blooms responsible for producing the toxin.
Story summarized from the original created by Steph Rodriguez on ww2.kqed.org, see more information here.
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