The contamination of seafood by algal toxins regularly affects animals living in several areas of the world, and the number of toxic phycotoxins which are being characterized is steadily increasing. The extreme dynamics characterizing the field of algal toxins has stimulated the development of tools to be implemented in the monitoring of contamination of seafood by individual toxin classes. Under these circumstances, functional assays which can encompass the analytical potential of chemical methods and the predictive features of biological tests are sought. A variety of functional assays for the detection of phycotoxins has been developed in the last 20 years, and the analysis of their features reveals that their specificity is related to the hierarchical level of the biological response to the toxin that has been exploited for its detection. Ideally, analytical methods which could allow accurate estimates of the overall toxicity of multiple classes of toxins in a single procedure would provide the best means for the highest standards in consumer protection and the most rational and economical tools in the management of risks posed by phycotoxins in a wider scale. The achievement of a "systemic functional assay for marine biotoxins" does not appear to be at hand, but its inclusion among the foreseeable events is fully justified by the new research tools and approaches which have become available for the high throughput analysis of entire molecular domains at the cellular level.