Marine algal toxins in shellfish - a Japanese-Norwegian collaboration

In trade with shellfish, it is of importance that seafood is safe for consumption. Several algal toxins have long been known to accumulate in shellfish and cause poisoning of shellfish consumers. New toxins seem to appear world wide, and rapidly spread to new areas. In Norwegian waters, azaspiracids have recently been detected in mussels, and the pectenotoxins and okadaic acid group of toxins have caused problems for the Norwegian shellfish industry sector as well as consumers. Effective management of the se toxins requires rapid and affordable analytical methods, knowledge about metabolites formed when the toxins are ingested by shellfish, and information on the toxicity of such metabolites when ingested by the consumers. The introduction of risk assessm ent based food safety management systems in the shellfish sector, have put increasing focus on the lack of cost-effective HACCP tools that are suitable for in-process testing and verification through end product testing. This involves the development and validation of rapid assays like ELISAs and rapid tests in the lateral flow immunoassay format. Furthermore, there is a need for early-warning tools, such as toxin adsorbent disks (TADs), that can be used as a simple and sensitive way of monitoring emerg ing toxic blooms in the water masses. This involves the passive adsorption of biotoxins onto porous synthetic resin filled disks, and their subsequent extraction and analysis. The method is founded on the observation that algal cells leak toxin, including the lipophilic algal toxins, into the seawater. In cases where the toxin producer is unknown, TADs are particularly useful as early warning tools since they have the advantage of directly targeting the toxic compounds of interest. When coupled with appro priate analytical techniques (e.g. LC-MS/MS multi-toxin screens, ELISA assays, receptor binding assays), the method has the potential to offer valuable data as a supplement to ongoing monitoring of algal toxins.