River biota as indicators and scavengers of heavy metal pollution

Bioaccumulation of heavy metals by different groups of aquatic organisms i.e. algae, macrophytes and animals (mollusc and fish) encountered in river Ganga was studied with a view to ascertaining if these could be used as scavengers for reducing heavy metal toxicity. In algae (Anabaena and Cladophora) accumulation of zinc was maximum while among the macrophytes, Potamogeton crispus showed comparatively higher metal accumulating capacity. In general, mollusc were better metal accumulators than algae, macrophytes and fish and thus these organisms could be used as scavengers as well as indicators of high levels of metal pollution in aquatic ecosystems.