Okadaic acid

Okadaic acid is a polyether marine toxin produced by certain dinoflagellate algae, notably species of Dinophysis and Prorocentrum, which accumulates in filter-feeding bivalves such as mussels, oysters, and scallops. It is the principal causative agent of diarrhetic shellfish poisoning, an illness marked by nausea, vomiting, diarrhoea, and abdominal pain beginning within hours of eating contaminated shellfish. Because the toxin is heat-stable and survives cooking, safety depends on monitoring algal cell counts and toxin levels in shellfish waters and closing harvest areas when limits are exceeded. Regulatory programmes across shellfish-producing regions enforce maximum levels to protect consumers from this recurring hazard.