Toxic Bloom Sickens California Sea Lions

A severe toxic algal bloom is causing widespread poisonings among sea lions and other marine mammals along the California coast. Dozens of sea lions have been affected by domoic acid, a neurotoxin produced by algae, which can lead to seizures and heart failure. The Marine Mammal Center reports a significant flare-up in cases, particularly in Monterey and Santa Cruz counties, with over 100 cases already reported in 2026, surpassing typical annual numbers.

Sea lions ingest the toxin by eating contaminated fish, and due to their hydration methods, they receive large doses with no way to flush it from their systems. This repeated exposure can cause permanent neurological damage. Experts note the illness has become more unpredictable, appearing year-round rather than just in summer, and warmer ocean temperatures linked to El Niño may be contributing to the severity of the blooms.

Authorities are urging the public to maintain a safe distance of at least 100 yards from any sick or stranded sea lions, as they can be dangerous and unpredictable. Reporting sightings to NOAA or the Marine Mammal Center is crucial for rescue efforts. Volunteers are also needed to assist with the physically demanding operations of rescuing these distressed animals.