Mussel Danger: LA County Warns of Toxic Algae

Public health officials in Los Angeles County have issued a strong warning concerning the consumption of recreationally harvested mussels along California's ocean shoreline. A quarantine order will be active from May 1, 2026, through October 31, 2026, covering all mussel species gathered by recreational harvesters. This advisory spans the entire California coast, from the Oregon to the Mexican border, including all bays and inlets within Los Angeles County.

During this period, officials strongly advise against human consumption of these mussels. Warmer months see mussels concentrating naturally occurring toxins, such as those causing paralytic shellfish poisoning (PSP) and domoic acid poisoning. These poisons are highly dangerous and are not neutralized by cooking. Commercial shellfish from approved sources are not affected by this order, as they undergo rigorous testing.

Symptoms of exposure can range from neurological to gastrointestinal issues. There is no specific antidote for these toxins, and treatment is supportive. Medical attention should be sought immediately if symptoms appear after consuming mussels harvested for recreation. Individuals are encouraged to submit a Foodborne Illness Report if they experience any adverse effects.