Diarrhetic mussel poisoning in the Netherlands related to the dinoflagellate Dinophysis acuminata.

In 1961, 1971, 1976, 1979 and 1981 several cases of mussel poisoning have been recorded in the Netherlands. During the outbreak of this phenomenon, consumers of raw or cooked mussels, Mytilus edulis, obtained from the Dutch shellfish-growing areas, showed gastrointestinal disorders. Investigations revealed that phytoplankton bloom of the dinoflagellate Dinophysis acuminata Claparède & Lachman preceded the mussel poisoning. After the disappearance of these dinoflagellates, the toxicity of mussels was slowly diminishing and no longer detectable after a cleansing period of about 4 weeks at 14-15 degrees C. Toxicity of mussels could easily be detected by the rat bioassay. The chemical structure of the toxin, isolated in 1981 from toxic mussels from the Dutch Waddensea has been determined in Japan as a dinophysis-type toxin.