Health Advisory for Recreational Mussel Harvesting Along the California Coast

Quarantine Order for California Mussels Issued by Health Officials

The California Department of Public Health has announced a six-month quarantine for mussels collected along the state’s ocean shore, warning that these shellfish should not be consumed by humans.

This quarantine spans from the Oregon border to the Mexican border, encompassing all bays, inlets, and harbors in Los Angeles County. The Los Angeles County Department of Public Health is conducting daily surveillance to monitor illness cases linked to the consumption of mussels and other bivalve shellfish. In collaboration with state officials, the department actively collects shellfish samples for testing.

During this quarantine period, mussels can accumulate naturally occurring toxins that pose significant health risks, including paralytic shellfish poison and domoic acid biotoxins, which also affect clams, oysters, and scallops. Toxin levels in shellfish can fluctuate unpredictably and may rise rapidly, making annual quarantine measures essential. These measures work alongside year-round monitoring, public education efforts, shellfish advisories, and commercial closures when necessary, as cooking does not eliminate these toxins.

It is important to note that the advisory does not extend to commercially sourced shellfish from approved suppliers. For those using mussels as bait, they must be sold in containers clearly marked in bold type as "MUSSELS FOR BAIT ONLY, UNFIT FOR HUMAN FOOD," as per health regulations in Los Angeles County.

Symptoms associated with domoic acid poisoning, commonly known as amnesic shellfish poisoning, can manifest anywhere from 30 minutes to 24 hours after consuming contaminated seafood.