The bioaccumulation of heavy metals in fish Cyprinus carpio such as zinc, chromium, copper, cadmium and lead were evaluated during the year of July 2011 to July 2012 from Vettar Estuary, Nagapattinam Coastal area, Tamilnadu. The fish organs viz., gill, intestine, liver, kindey and muscle from the selected freshwater fish was carefully dissected for determination of heavy metals. Bioaccumulation of metals exhibited spatio-temporal variations. In general, the accumulation is maximum during the monsoon season and minimum during summer season. Such a relationship may be due to the background level of metals and due to the presence of favourable environmental physico-chemical characteristics. Gill and intestine exhibited maximum levels of accumulation owing to the route of entry via water and food. In monsoon season even the muscle, edible part of the fish, exhibited higher levels of non-essential metals, which exceeded the FAO’s safe permissible limits. The levels of heavy metals were determined using Clicos Sl- 176 double beam Atomic Absorption Spectrophotometer (AAS). The heavy metals accumulated in freshwater fish species might be due to increase in agricultural influx waters, domestic waters and anthropogenic activities.
