A Comparative Assessment of the Heavy Metal Loads in the Tissues of a Common Catfish (Clarias Gariepinus) From Ikpoba and Ogba Rivers in Benin City, Nigeria – AFS 2007082/9104; September 18, 2007; Department of Animal Science, Faculty of Agriculture, Ambrose Ali University, Ekpoma, Edo State, Nigeria. Department of Fisheries, Faculty of Agriculture, University of Benin, Benin City, Edo State, Nigeria; E. E. Obasohan ; J. A. O. Oronsaye and O. I. Eguavoen
ABSTRACT:
This investigation determined and monitored the concentrations of Cu, Zn, Mn, Cd, Cr, Ni and Pb in the tissues (Offal, Gills, Liver and Muscle) of the Catfish, Clarias gariepinus from Ikpoba and Ogba Rivers in Benin City, Nigeria between January and June, 2006. The same metals were also determined in the water of the two rivers. The results showed that the water and tissues of the fish from both rivers were contaminated to varying levels. The levels of the metals (except Ni and Pb) in the water of both rivers were not different at the sample stations of each river and between the rivers. The levels of Mn, Cd, Ni and Pb in water of the rivers exceeded WHO and FEPA maximum acceptable limits for drinking water and the mean natural background levels for African inland waters. It was also showed that most metals levels in fish tissues varied between stations and also between rivers. Tissues metal levels exhibited no particular trends, but seemed to be higher in offal and gills. Metal levels in all tissues were all greater than the maximum acceptable limits in food fish and thus indicated contamination to levels that could pose potential hazards when consumed. It was therefore inferred that the fishes of the rivers were unfit for human consumption. Based on the above findings, close monitoring involving human health risks assessment in relation to environmental pollution of Ikpoba and Ogba Rivers were strongly recommended.