Unsafe toxin levels sometimes occur outside the annual quarantine period. CDHS declares special local quarantines whenever unsafe levels of toxins appear. Domoic acid poisoning has never been reported in humans in California. The annual mussel quarantine does not apply to companies licensed by the State as certified shellfish harvesters. CDHS tests and certifies the shellfish from these companies to be safe.
Oysters are the principal bivalve shellfish harvested commercially in California.
Other shellfish are available in California retail food stores and restaur- ants throughout the year. State and federal agencies regulate all commercially harvested shellfish in the United States. These regulations make certain that only safe and wholesome shellfish are available to the consumer. Mussels may be harvested and sold for fish bait at any time. Shellfish Information Line CDHS provides a recorded current update on marine toxin activity in California.