The California Department of Public Health (CDPH) has issued two sets of advisories against consuming Dungeness Crab in parts of Northern California due to risk of Amnesic Shellfish Poisoning from domoic acid (DA).

CDPH conducts regular sampling and biomonitoring of shellfish for this toxin, and found high levels in significant portions of crabs caught within the affected areas: spanning from Oregon border down to Cape Mendocino, and Sonoma County to Point Reyes.

Our California-Harmful Algae Risk Mapping (C-HARM) system generates predictions of harmful algal bloom (HAB) conditions. Across the same period and spatial extent of sampling that informed these CDPH advisories, model output reflected a high probability for dangerous concentrations of domoic acid in the certain types of phytoplankton that produce it, and end up as a component in the regional food-web.

Domoic acid toxicity is the cause of Amnesic Shellfish Poisoning, which is a dangerous illness to humans. The toxin presents a potentially (and historically) devastating disruptor to the well-being of marine mammals and their broader ecosystem.

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