Accumulation of Phycotoxins in the Mussel Mytilus galloprovincialis from the Central Adriatic Sea

Surveys of DSP (Diarrheic Shellfish Poisoning) toxin profiles in the mussel Mytilus galloprovincialis from coastal waters of the central Adriatic Sea, over the years 1995 to 2001, demonstrate that incidents of shellfish toxicity in this area are dominated by the occurrence of okadaic acid (OA) and a PTX derivative, 7-epi-pectenotoxin-2-seco acid (7-epi-PTX-2SA). Toxin composition and the relative ratio of toxic components in shellfish is in correlation with the occurrence of DSP producing organisms from the Dinophysis species along with Prorocentrum micans and Lingulodinium polyedrum. The occurrence of D. sacculus shortly before the appearance of OA in shellfish implicates its possible involvement as the source of toxicity. In thecentral Adriatic, the infestation period generally ranges from June to August. Augmented toxin production may shift the depuration phase to September; however, the length of decontamination period is not in correlation with increased initial toxicity. The mussel M. galloprovincialis may retain contamination with 7-epi-PTX-2SA beyond the commonly recognized infestation period, extending the risk of human poisoning from consumption of seco-contaminated seafood