Bioaccumulation of heavy metals in muscle tissue of fishes from selected aquaculture ponds in east Kolkata wetlands

Heavy metals i.e. Copper (Cu), Zinc (Zn), Manganese (Mn), Iron (Fe), Cadmium (Cd), Nickel (Ni), Mercury (Hg) and Arsenic (As) were analyzed in 35 samples of the fish muscle, from East Kolkata Wetlands (EKW). The concentration of heavy metals was in order of, Fe > Zn > Cu > Mn > Ni > As > Hg > Cd. The essential metals, such as iron, zinc, copper and manganese were in higher concentrations and, the non-essential and toxic metals such as cadmium, nickel, mercury and arsenic were generally low. The bioaccumulation pattern of metals in different species of fishes was as: Hypophthalmichthys molitrix > Oreochromis nilotica > Labeo rohita > O. mossambica > Channa marulius > Catla catla > Punctius ticto. The Pearson’s moment correlation coefficients among heavy metal were investigated and presented. This study revealed that fishes from the East Kolkata Wetland (EKW) may not be harmful to consumers since; levels of heavy metals were below the permissible limits issued by FAO/WHO. However, intensive study on fishes is a need to determine the bioaccumulation of heavy metals and other toxic pollutants i.e. pesticides, PCBs, PAHs, and dioxins in this area.