Variation of residual mercury in penaeid prawns from Rushikulya estuary, east coast of India

Two commercially important penaeid prawn species were collected from Rushikulya estuary for assessment of Hg content during March 1994 to February 1995. The levels of mercury were determined by employing modified,Bethege apparatus and subsequently using a mercury analyser. The study revealed that Hg concentration in the edible parts of Penaeus monodon and Penaeus indicus at both the stations was higher than that in the non-edible parts during monsoon. Reverse trend prevailed in the premonsoon season. The station II, located near a chlor-alkali factory, always exhibited higher values as compared to station I located near the mouth. Further higher Hg concentrations in P. monodon and lower in P, indicus was noticed at both the stations. Residual concentrations of mercury in the organisms were found to be fairly below the legally permissible limit of Hg in fish and fishery products in India.