Trace metal concentrations in marine zooplankton from the western Bay of Bengal

Abstract

Trace metal contents in zooplankton samples were estimated as a part of Marine Research-Living Resource Programme (MRLR) programme at 24 stations to establish the importance of these metals in the Bay of Bengal. The average concentration of Fe, Co, Ni, Cu, Zn, Cd and Pb in zooplankton from the Bay of Bengal indicates that it is slightly enriched in coastal samples than offshore samples. The heavy river discharge in the east coast of India might be related to the increased metal bio-availabilities in seawater and hence an increased uptake of metals by zooplankton from coastal areas than offshore areas. The zooplankton species examined showed great accumulations of metals, with bioaccumulation factors in the range greater than 15,000 to 40,000,000 with respect to the concentrations (soluble fractions) in marine waters. Metal concentrations recorded in the Bay of Bengal zooplankton may be used as background levels for future studies, a body of water about which information is still very scarce.