Wildlife officials are investigating a possible outbreak of domoic acid poisoning among sea lions in the Pacific Ocean. Over a four-day period, the California Wildlife Center (CWC) received at least 14 reports of distressed sea lions, sparking concern over the potential impact of a toxic algal bloom.
Domoic acid is a naturally occurring neurotoxin produced by the algae Pseudo-nitzschia. When small fish, such as anchovies or sardines, consume the algae, the toxin accumulates in their bodies. Predators, including sea lions, then ingest the contaminated fish, leading to severe health complications. Even at low doses, domoic acid can cause irreversible brain and heart damage in marine mammals.
Domoic acid poisoning, also known as Amnesic Shellfish Poisoning (ASP), is also caused by consuming seafood contaminated with domoic acid, a neurotoxin produced by certain species of marine diatoms.
When Pseudo-nitzschia populations rapidly grow due to favorable conditions they release domoic acid into the water. Bioaccumulation in Marine Life – The toxin accumulates in shellfish, anchovies, sardines, crabs, and other seafood that feed on these algae.
Sea lions suffering from domoic acid toxicity exhibit:
- Seizures
- Disorientation and “stargazing” (a characteristic upward head tilt)
- Lethargy or comatose states
While officials have not yet confirmed domoic acid as the cause, recent heavy rains and runoff have created conditions conducive to toxic algal blooms in the ocean, making it a strong suspect.
Residents and beachgoers are urged not to approach or interact with distressed sea lions. The animals may be suffering and confused, posing a risk of injury if they feel threatened.
Wildlife officials continue to monitor the situation and are working to determine the full extent of the outbreak.
