Comparative study of the patterns of bioaccumulation of essential (Cu, Zn) and non-essential (Cd, Pb) trace metals in various estuarine and coastal organisms

Abstract

The patterns of accumulation of essential and non-essential trace metals have been studied comparatively in worms, molluscs, crustaceans, and fish exposed to short-term experimental contaminations and low chronic contaminations in a polluted environment. In short-term contaminations, the concentrations X of the non-essential metals cadmium and lead in the organisms depend mainly on their environmental level Y according to the power function Y = aX b . For copper - an essential metal - this equation is also suitable to describe the bioaccumulation in some species ( Nereis diversicolor O.F. Müller, Scrobicularia plana (da Costa), Gammarus zaddachi Sexton) for a large range of experimental overloads. As for the mussel Mytilus edulis L., this equation is accurate for medium or high overloads only. All the species are able to control the level of the essential zinc in their tissues but for both copper and zinc the best regulators are the more highly evolved forms including decapod crustaceans and fish. The in situ chronic contaminations support the same conclusions. In one fish and one decapod crustacean species it has been shown that the regulation mechanisms may be functional since early life stages. When the duration of exposure to essential metals increases, the regulation mechanism is, however, disturbed by more and more low additional concentrations in sea water.