Sea lions exposed to a neurotoxin produced by a form of algae have been washing up on a stretch of California coast line. Those not killed by the algae are behaving in some very strange ways, including disorientation and staring into space.
The Channel Islands Marine & Wildlife Institute, a non-profit dedicated to rescuing and rehabilitating marine life in the area around the Santa Barbara Channel, said in social media posts they have been struggling to keep up as they’re bombarded with calls and emails. The CIMWI has received roughly 100 reports per day about the sick animals, though some reports have been about the same animal.
The sea lions are displaying several alarming symptoms, including staring into space, disorientation, weaving their heads, mouth foaming, lethargy, unresponsiveness, muscle spasms, seizures, and an inability to get out of the tide. Those are signs they are suffering from domoic acid poisoning.
Domoic acid is produced by pseudo-nitzschia, a form of algae that usually blooms during the spring and fall when cold water wells to the surface, bringing along nutrients the algae feeds on. The algae is consumed by small fish, shellfish, bivalves, and other small animals that are then, in turn, eaten by sea lions, dolphins, and birds. In some extreme cases, domoic acid consumption is fatal for the sea lions. In June 2023, a major bloom of pseudo-nitzschia led to over 1,000 reports of sick or dead marine animals in a single week in the same area.
The severity of the current bloom isn’t clear, as data from the Southern California Coastal Ocean Observing System is not yet available. People who see a sea lion displaying symptoms are advised not to touch or approach the animals. Instead, they should note their location and contact the CIMWI’s rescue team.
The CIMWI advised the public that it can take time to investigate each report due to a limited number of volunteers responding along the 155 miles (250 km) of coast in Santa Barbara and Ventura counties. According to an emailed statement, the institute said 25 sea lions have been rescued thus far.
Staff members from nearby Vandenberg Space Force Base have been aiding the CIMWI in its rescue efforts. The base said in a statement that, alongside rescuing beached sea lions, military personnel have been testing marine life found at the facility for toxins.