The California Department of Public Health has implemented a six-month quarantine on recreational mussel harvesting along the state’s coastline, citing the risk of naturally occurring toxins that can cause severe illness. The ban extends from the Oregon border to the Mexican border, including all areas within Los Angeles County.

Quarantine Details and Scope

The quarantine order, issued on Wednesday, advises against human consumption of mussels gathered from California’s ocean shores. This includes all bays, inlets, and harbors throughout the state. The Los Angeles County Department of Public Health actively monitors for illnesses potentially linked to shellfish consumption.

Toxin Risks and Symptoms

During the quarantine, mussels can accumulate highly poisonous toxins, including paralytic shellfish poison and domoic acid biotoxins. These toxins are found in various bivalve shellfish like clams, oysters, and scallops. Shellfish toxin levels are unpredictable and can increase rapidly.

Cooking does not eliminate these toxins. Symptoms of domoic acid poisoning, also known as amnesic shellfish poisoning, can appear within 30 minutes to 24 hours after ingestion. These symptoms include nausea, vomiting, diarrhea, abdominal pain, confusion, and potentially memory loss or neurological damage.

Bait Use and Public Safety

Mussels can still be used or sold as bait, but must be clearly labeled: MUSSELS FOR BAIT ONLY, UNFIT FOR HUMAN FOOD, in letters at least one-half inch in height. This annual quarantine, combined with ongoing surveillance and public education, is essential for protecting public health.