ABSTRACT
In Tunisia, the most important sector of aquaculture is shellfish farming industry. Unfortunately, in recent years this sub-sector knows many problems of shellfish contamination due to blooms of toxic algae. This phenomenon occurred for the first time in 1994 in the Gulf of Gabes after the proliferation of Karenia cf. selliformis which synthesizes gymnodimine, a potent neurotoxin. Following these effects, several collection sites especially Boughrara lagoon, were closed for extended periods. Recently, an atypical toxicity was detected, initial characterization studies carried out by LC-MS showed that the toxins detected probably belong to the family PSP toxins. The lagoon of Bizerte was also known since 2006, a repeatable events of contamination of mussels and oysters. As a result, many samples were DSP and PSP positive with concentrations up to 2100 microg eq.STX/100 g meat.