Combined toxicity studies on Perna spp.

Abstract

Knowledge of the interaction of various pollutants in the environment is necessary to set water quelity standards. The water body receiving the effluents can have pollutants of varied nature r u u l t i n g in a conglomeration of toxic components. Measurements of toxic effects of pollutants on sessile marine bivalves provide a valuable indication of environmental impact since the resident time of such animals in any locality follows a specific pattern In this connection a multiple factor approach to study toxic effects is warranted. With this view in mind combined toxicity studies employing heavy metals. crude and pesticides were undertaken with mussels as target organisms. In the present document one of such investigations is reported. The joint action of silver (unvarying) + copper (varying) and copper (unvarying) 4- silver (varying) mixtures were delineated, in the case of Perna viridis these combinations reduced less than additive reaction whereas in Perna indica the relation was more then additive, species specific dependence in toxicity. Silver was proved to be highly toxic when present alone in the teat medium The results clearly show that the interaction between two or more pollutants