Sea lions die in Northern California from suspected toxic poisoning

A growing number of sea lions are falling ill or dying along Northern California beaches due to suspected domoic acid poisoning. On Monday morning, a large California sea lion was found exhibiting erratic behavior, including head weaving and seizures, at Crissy Field in San Francisco. The animal died before response teams could arrive.

The Marine Mammal Center reports that blooming algae is producing intense levels of domoic acid, a neurotoxin that accumulates in small fish like sardines and anchovies. When sea lions consume these contaminated fish, the toxin can attack the brain, causing seizures, heart failure, and permanent brain damage.

Rescue efforts have intensified, with the center receiving between 300 and 700 calls daily. While experts can attempt to flush toxins from animals if they are treated in time, many cases are discovered too late. This year, the number of rescues has already exceeded the annual average for the 600-mile California response area. Similar cases have been reported in Monterey, Santa Cruz, San Mateo, Marin, and Sonoma counties.