The objectives of this research are to conduct chemical and pharmacological studies of the as yet uncharacterized toxin of Atlantic shellfish poisoning caused by the toxic dinoflagellate, Gonyaulax tamarensis, with ultimate aims of devising preventive measures or antidotes, to study the pharmacological implications of possible therapeutic use, and also to study the dynamics of the toxins in biosystems. The experiments include isolation of toxins, a large scale culture of organisms, structure elucidation, immunochemical and pharmacological studies. Some other related deleterious dinoflagellates, including Gymnodinium breve, will also be studied.