HEAVY METAL ACCUMULATION IN MOLLUSCS AND SEDIMENT FROM UPPANAR ESTUARY, SOUTHEAST COAST OF INDIA

The concentration of (Cd, Co, Cu, Fe, Mg, Mn, Pb, Zn) were analyzed in sediments, shells and tissues of the molluscs Meretrix meretrix, Crassostrea madrasensis and Cerithidea cingulata from two stations of Uppanar Estuary, southeast coast of India. The concentrations of the heavy metals analyzed exhibited variations in sediments, tissues and shells of the study animal from all the two stations. Zn and Cu concentration were below the alarming level. In the present study Mg content was found to be higher in shell and tissue. The Fe content was found to be higher in sediment in both the stations, but it was the second highest metal recorded in shell and tissue. Cd and Co was minimum accumulated of all the metals estimated in sediment and animal whereas Mg was recorded maximum (548.3 +/- 5) in C. cingulata shell. All the metals analysed were within the safety level. The combined correlation of both the stations between the sediment vs. sediment, tissue vs. tissue, shell vs. shell were positively correlated and significant at P < 0.001 and P < 0.05 level. In addition to continuous contribution of pollutants due to human activities, industries may have a significant contribution of these metals in all the stations. As suggested by many reported studies found in the literature, regular biomonitoring of heavy metal concentrations at these sites is needed since Meretrix meretrix, Crassostrea madrasensis are a popular commercial bivalve in India.