Domoic Acid (a marine biotoxin) in fish and shellfish

Domoic acid is a potent neurotoxin that can cause symptoms such as nausea, vomiting, and diarrhea at lower doses and seizures, coma, irreversible memory loss (“Amnesic Shellfish Poisoning”), and death at higher doses. Domoic acid is produced by marine algal blooms under certain conditions. Domoic acid can temporarily build up in crabs, lobsters, clams and other fish and shellfish, making them hazardous to eat for humans, marine mammals, and birds. No human cases of domoic acid poisoning have been reported in California; however, mild cases may not be readily recognized. Domoic acid is considered responsible for hundreds of sea lion illnesses or deaths in the state.

OEHHA, in consultation with the Department of Public Health, recommends closures, delay of openings, and re-openings of fisheries based on high levels of toxic substances, including marine biotoxins such as domoic acid, under Fish and Game Code Section 5523. Recommendations to close or delay the opening of fisheries are made when levels of domoic acid meet or exceed the federal action level for this toxin. Recommendations for re-opening fisheries are made when domoic acid levels fall below the action level in two successive samples collected at least 7 days apart. Closures, delay of openings, and re-openings are implemented by the California Department of Fish and Wildlife. Check California Department of Fish and Wildlife’s Health Advisories for Finfish, Shellfish, and Crustaceans, or call California Department of Public Health’s Shellfish Biotoxin Information Line (800-553-4133) for current advisories and closures.



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Fish, Ecotoxicology and Water Section

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1001 I Street
Sacramento, CA 95814
Phone: (916) 423-7572

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