Diarrhoetic shellfish poisoning toxins in Cancer pagurus Linnaeus, 1758 (Brachyura, Cancridae) in Norwegian waters

During the summer of 2002 there were several episodes of human intoxication after consumption of brown crabs ( Cancer pagurus ) caught along the Norwegian south coast. The toxic agent was one of the well-known phycotoxins, the diarrhoetic shellfish poisoning (DSP) complex, routinely found in blue mussels ( Mytilus edulis ). This toxin has not previously been documented in brown crabs. The route and rate of toxin accumulation as well as the rate of toxin depuration in crabs were determined in laboratory experiments. The DSP toxins only accumulate in digestive organs (hepatopancreas, HP) in the crabs. When fed with blue mussels containing more than 1000 μg of okadaic acid equivalents kg −1 , the crabs accumulated 3-30% of the toxin. After 2 weeks, the average toxin level in the crabs exceeded the preliminary limit of DSP toxins at 400 μg okadaic acid equivalents kg −1 HP established by the Norwegian Food Safety Authority. A 50% reduction in toxin level was observed after 14-18 days when the crabs were fed fish instead of toxic mussels.