Assessment of total mercury level in fish collected from East Calcutta Wetlands and Titagarh sewage fed aquaculture in West Bengal, India.

Total mercury levels were quantified in Tilapia mossambicus, Cirrhinus mrigela and Labio rohita, captured from East Calcutta Wetlands and Titagarh sewage fed aquaculture ponds. The bioconcentration factor of collected fish was assessed. Total mercury level ranged from 0.073 to 0.94 microg/g in both pre and post monsoon season. T. mossambicus in both season and C. mrigela at pre monsoon, cross the Indian recommended maximum limit (0.50 microg/g wet weight) for food consumption and according to World Health Organization guidelines all fish were not recommended for pregnant women and individuals under 15 years ages. A significant correlation was observed between mercury content of aquaculture pond water and fish muscle tissue. Total mercury concentration in experimental sites were higher than the control area (Wilcoxon Ranked-Sum test p > 0.05), which suggested the connection between mercury bioaccumulation and sewage fed aquaculture.