Sea lion dies at San Francisco beach after possible poisoning from algae bloom
Distressed sea lion spotted at San Francisco beach
A sea lion spotted in distress at a San Francisco beach Monday morning has died, according to the Sausalito-based Marine Mammal Center, which sent volunteers to help the mammal.
SAN FRANCISCO - A sea lion spotted in distress at a San Francisco beach Monday morning has died, according to the Sausalito-based Marine Mammal Center, which sent volunteers to help the mammal.
Sea lion dies on San Francisco beach
What we know:
The sea lion was found at a Presidio beach, just east of the Golden Gate Bridge.
Video shows the sea lion in the sand as beachgoers move throughout the area.
According to volunteers with the Marine Mammal Center, the sea lion likely developed domoic acid poisoning from algal blooms.
The California Academy of Sciences will collect the animal from the beach and perform a necropsy to determine its exact cause of death.
Trend of sick sea lions along California's coast
Big picture view:
This latest case is part of a growing trend of sick sea lions along California's coastline.
Warmer ocean temperatures and El Niño conditions are infecting bottom-dwelling fish, causing neurological issues in the marine mammals that consume them.
The Marine Mammal Center said last week that it's handling a massive influx of sick sea lions across its 600-mile territory.
By the numbers:
Response hotlines are seeing between 200 and 650 calls a day, according to Katie D’Innocenzo, public information officer for the center.
Time is critical for these animals, as treatment with clean fish and fluids can lead to recovery if teams reach them in time; otherwise, the condition is fatal.
The toxin behind the illness, domoic acid, is the same substance that severely damaged or ruined Dungeness crab seasons in years past.
Because bottom-dwelling Dungeness crabs feed on the same algae debris, concerns are growing about the potential impact on the upcoming commercial season.
The Source: Information in this story was reported by KTVU reporter Christien Kafton with information gathered from the Marine Mammal Center in Sausalito, Calif. Portions of the story were reported in a previous KTVU story on sea lions published Sept. 4, 2026.