Bioaccumulation of Trace Metal in Two Species of Crabs from Chilika Lagoon, East Coast of India

Abstract

Two important species of crabs from the Chilika lagoon were selected for analysis of trace metal concentration. These two species were Scylla serrata and Portunus pelagicus, of which S. serrata attains the highest length of 13.2 cm and weight 238.52 gm, while the highest length and weight of Portunus pelagicus was observed to be 8.5 cm and 92.3 gm respectively. Heavy metal concentration of Mn, Fe, Cu and Zn was observed in the muscles, body carapace and leg carapace. The metal concentration was lowest in the muscle. Metal concentration of Mn, Fe, Cu and Zn varied from 3.8 to 5.5 ppm, 14.4 to 18.4 ppm, 6.1 to 9.1 ppm and 152 to 211 ppm dry weight respectively in the leg carapace. Similarly the concentration of metals in the muscle were in the range of 3.8 to 5.1 ppm, 14.4 to 17.5 ppm, 4.8 to 7.4 ppm and 129 to 188 ppm dry weight for Mn, Fe, Cu and Zn respectively. Metal concentration in the body carapace for these four metals varied from 3.8 to 5.3 ppm, 15.2 to 18.2 ppm, 5.8 to 8.6 ppm and 152 to 193 ppm dry weight respectively. Scylla serrata contained higher muscle concentration of Mn, Fe, Cu and Zn than the other species of crab, viz., P. pelagicus. There was no correlation between body size and heavy metal concentration. However, the metal concentration found in the present study was lower to metal concentration levels of crab from other parts of the world and as such there is no public health problem in consuming these crabs from the Chilika lagoon, Odisha.