Studies on the resistance of marine bottom invertebrates to oxygen-deficiency and hydrogen sulphide

Abstract

Oxygen-deficient and H2S-containing marine areas are characterized by a decline in the number of species. In laboratory experiments with bottom invertebrates from various biotopes of the North Sea and the Baltic, comparative measurements of the resistance to oxygen-deficiency alone, and to the simultaneous presence of H2S, were carried out. The resistance values obtained show relations to the substratum on which the species naturally occur. The resistance to H2S is greater in those macrofauna species which show higher survival rates under oxygen-deficiency. Further experiments with isolated tissues demonstrate that the species specific differences in resistance occurring in whole animals are already based on the cell metabolism. In general, oxygen-deficiency and simultaneous presence of H2S were endured better in cold than in warmth, and at somewhat reduced pH-values (around 7). The dependence of this resistance on the salinity was only minimal in euryhaline species.