The California Department of Public Health (CDPH) has issued its annual mussel quarantine, effective from May 1 through October 31, 2025, warning recreational sport harvesters against consuming mussels gathered from the state’s ocean shorelines due to the risk of serious, potentially fatal, biotoxin poisoning.
The quarantine stretches from the Oregon border to the Mexican border, covering all bays, inlets, and harbors, including those in Los Angeles County. It applies only to recreationally harvested mussels and does not affect commercially sold shellfish from certified harvesters, which are subject to routine safety testing.
The seasonal restriction is implemented under California Health and Safety Code Section 131056 to prevent public exposure to naturally occurring marine toxins such as paralytic shellfish poison (PSP) and domoic acid. These toxins can build up in mussels and other bivalve shellfish like clams, oysters, and scallops. Cooking does not eliminate the toxins, making raw or cooked recreationally harvested shellfish dangerous to consume…