The California Department of Public Health (CDPH) coordinates a routine monitoring program along the California coast to sample mussels and other shellfish like clams and scallops for the presence of Paralytic Shellfish Poisoning (PSP) and domoic acid toxins. Commercial shellfish harvesters are also required to provide weekly shellfish samples to CDPH for PSP toxin assay and domoic acid analysis. If toxin levels are high enough, warnings and quarantines are issued to protect the recreational fishing public and shellfish consumers.
CDPH also has a coastwide, monthly seawater monitoring program which detects the naturally occurring, microscopic algae that produce PSP and domoic acid toxins. When toxin levels begin increasing, CDPH may expand its mussel sampling effort to include other seafood species. If toxin levels increase quickly beyond the federal alert level for either toxin, then CDPH may immediately issue a health advisory for all potentially impacted seafood species in the affected region.
The Office of Environmental Health Hazard Assessment (OEHHA), in consultation with CDPH, recommends closures, delay of openings, and re-openings of recreational and commercial fisheries based on high levels of toxic substances, including marine biotoxins such as domoic acid, under Fish and Game Code 5523. Recommendations to close or delay the opening of fisheries are made when domoic acid levels meet or exceed the federal action level for this toxin. Closures, delay of openings, and re-openings are implemented by the California Department of Fish and Wildlife (CDFW). Recommendations for re-opening fisheries are made when domoic acid levels fall below the action level in two successive samples collected at least seven days apart.
OEHHA also issues safe eating guidelines, or consumption advisories based on the amount of mercury or other chemical toxins found in finfish, shellfish and crustaceans. Consumption advisories can help to reduce your exposure to chemicals in sport fish—fish that you and your family or friends catch.
This page was established as a source of information for fishermen and the fishing industry. When circumstances arise, marine biotoxin-related fishery closures, delay of openings, re-openings, CDPH warnings, quarantine information, and health advisories about consuming California's ocean finfish, shellfish and crustaceans will be posted here.