Abstract:

A comparative analysis of the physiology and toxin composition was performed on a suite of clonal cultures of the potentially toxic dinoflagellate Alexandrium tamarense. These were established from resting cysts or vegetative cells isolated from sediment or the water taken from the coasts of Greenland, Iceland, Chukchi Sea and Gulf of Maine. Maximum growths were observed between 38 µmol·m^–2·s^–1 and 91 µmol·m^–2·s^–1. No dcGTX2 was detected in all 12 isolates, toxin content significant variation was observed. In general, toxin contents and toxicity were generally highest at higher irradiation. This may indicate that the genetically determined toxin profiles in A. tamarense species are more complex than previously appreciated.

Key words: Alexandrium tamarense, the Arctic, Gulf of Main, Irradiation, PSP toxins