Dangerous levels of the nerve toxin domoic acid have been detected in some of these species and may be present in the other species not yet tested. Domoic acid is a naturally occurring toxin that can cause illness or death in humans.
No cases of human poisoning from domoic acid are known to have occurred in California.
This advisory is in addition to the current health advisory for the same seafood items along the Ventura coast that was issued on August 20 and the annual quarantine on the sport-harvesting of mussels along the entire California coastline that took effect May 1.
This warning does not apply to commercially sold clams, mussels, scallops or oysters from approved sources. State law only permits state-certified commercial shellfish harvesters or dealers to sell these products. Shellfish sold by certified harvesters and dealers are subject to frequent mandatory testing.
Symptoms of domoic acid poisoning can occur within 30 minutes to 24 hours after eating toxic seafood. In mild cases, symptoms may include vomiting, diarrhea, abdominal cramps, headache and dizziness. These symptoms disappear within several days. In severe cases, the victim may experience difficulty breathing, confusion, disorientation, cardiovascular instability, seizures, excessive bronchial secretions, permanent loss of short‑term memory, coma, and death. Visit Annual Mussel Quarantine – Frequently Asked Questions for additional information.
To receive updated information about shellfish poisoning and quarantines, call CDPH toll-free “Shellfish Information Line” at (800) 553-4133.