Mercury in the Biotic and Abiotic Matrices along Bombay Coast

Abstract

Studies conducted during 1983-84 revealed that maximum Hg accumulation was in the surface sediment deposited in the vicinity of discharge zones, towards the northern region of the Thana creek. The levels in sediment decreased gradually downstream towards the mouth of the creek. Furthermore, no positive correlation between organic matter and Hg was evident in the sediment samples. Arcid blood clam Anadara granosa (Order: Taxadonta) and gobiidfish (mudskipper) Boleophthalmus boddaerti from Trombay coast (Bombay) monitored at monthly intervals showed an average body burden of 0.8 plus or minus 0.3 and 0.63 plus or minus 0.1 mu g.g-1 dry weight edible tissue respectively. A. granosa displayed strong seasonal variation in bioaccumulation of Hg with the highest level being recorded during monsoon months and the lowest in premonsoon period. Bioaccumulation of Hg (total) in the blood clams per unit dry weight was independent of body weight. Total Hg in 24 species of pelagic fish including sharks and teleosts sampled from commercial landings varied in the range of 0.03 to 0.82 mu g.g-1 dry tissue.