Lugworm mortalities and a bloom of Gyrodinium aureolum Hulburt in the eastern Irish Sea, Autumn 1971

Abstract

A bloom of the dinoflagellate Gyrodinium aureolum Hulburt in the eastern Irish Sea during September and October 1971 was accompanied by unusual mortalities of Arenicola marina L. and Echinocardium cordatunt Pennant. Observations in the field and laboratory suggest that the mortalities may not have been directly related to the occurrence of Gyrodinium but could have been a consequence of unusual climatic conditions which resulted in oxygen depletion in benthic substrates. The decomposition of the bloom possibly aggravated the situation.