Marine algal toxins - source organisms, accumulation and depuration in mussels, expanding profiles, and toxicology

In trade with shellfish, it is of importance that seafood can be safely consumed. ?New? toxins seem to appear world wide, and rapidly spread to new areas. In Norwegian waters, azaspiracids (AZAs) have recently been detected in mussels. Since the source or ganism of AZAs in mussels is unknown, the project will attempt to identify the producer by analysis of plankton by cell picking, and reanalyses of existing monitoring data. If the producer is identified, the project will try to cultivate the organism. St udies on toxicity of combined exposure to AZAs and other lipophilic toxins will be performed to achieve information about possible synergistic effects. Furthermore, DTX-2, an analogue in the OA-group that has hitherto not been found in Norwegian shellfish , is now emerging in Norway. More information about the relative toxicity of this and other analogues is necessary when moving from mouse bioassays to analytical methods. The project will improve the analysis of the AZAs and OA-group toxins down to single algal cell level in progress with the availability of new and advanced instrumentation. Accumulation and depuration of OA-group toxins, and to some degree AZA, in mussels will be studied using natural occurrences of the toxins. Furthermore, OA-group toxi ns in mussels will be studied in relation to Dinophysis concentrations (using natural occurrences), toxin concentration per cell, and the ratio of Dinophysis to other algae, followed by depuration studies at different seasons and under varying environment al conditions. The cellular localisation of the OA-group toxins in mussel tissues will be studied in order to increase the understanding of the depuration mechanisms. The results from the project will be communicated to the Food Control Authority in order to provide a better basis for risk management, and to the shellfish industry for better production planning.