Physicochemical Properties of Water and Heavy Metals Concentration of Sediments, Feeds and Various Farmed Tilapia (Oreochoromis niloticus) In Bangladesh

Heavy metals to man through aquatic life occur with the consumption of affected fish which is detrimental to the human body, having toxic and carcinogenic effects. In Bangladesh, the practice of Tilapia (Oreochromis niloticus) culture has become popular due to its great demand to people. This study aimed at determining levels of Cd, Cr, Cu, Pb, Ni in feed used for tilapia culture (N=18), in sediment (N=9) and water (N=9) of three culture pond of three different farms of Noakhali region in Bangladesh. Heavy metal concentration was detected by Atomic absorption spectroscopy. The average metal concentration in fishes of farm 1, farm 2 and farm 3 following trend Pb>Cr>Cu>Ni>Cd, Pb>Ni>Cr>Cu>Cd, and Pb>Ni>Cu>Cr>Cd, respectively. The level of selected heavy metals was below detection limit in a water sample. The order of heavy metal concentration in feed samples of each farm was decreased in the similar sequence of Cu>Cr>Ni>Pb>Cd. Heavy metal concentrations in the sediment of farm 1 was decreased in the order of Cu>Ni>Pb>Cr>Cd but metal concentrations in the sediment of farm 2 and farm 3 were decreased in the similar manner of Ni>Cu>Cr>Pb>Cd. The results show evidence of bioaccumulation of heavy metals in the fish with alarming levels that are higher than IAEA-407 limits, therefore, posing a potential risk for the consumer.