Comparative Evaluation of Heavy Metal Contents in Tilapia and Catfish Collected from Saki dam, Oyo State, Nigeria

Abstract

The present study was conducted to evaluate the anti-nutrients, proximate and mineral composition in catfish and tilapia fish collected from Saki dam. The gills, body and head parts of each fish sample were separately digested by using aqua regina and another set was dried and then ground separately before taken for laboratory analysis.  For tilapia fish, Cd concentration was the same at each part of the fish (0.28±0.00 mg/kg), the Pb, Zn, Fe, and Cr concentrations ranged from 0.50±2.17 to 5.22±1.51 mg/Kg, 0.86±0.19 to 2.86±0.45 mg/Kg, 0.74±0.03 to 1.93±0.01mg/Kg and 0.95±0.20 to 1.59±0.19 mg/Kg respectively. Pb had the highest concentration and was found at the head of the fish. In catfish, the Cd was not detected in the gill but its highest concentration (0.04±0.01 mg/Kg) was found in the head. Pb, Zn, Fe and Cr concentration ranged from 0.12±1.13 to 2.99±0.65 mg/Kg, 1.24±0.31 to 6.13±0.75 mg/Kg, 0.95±0.02 to 1.26±0.10 mg/Kg and 0.41±0.10 to 0.56±0.26 mg/Kg respectively. The results showed that all the parts tested contain trace amounts of the elements analyzed. Zn was found as the element with the highest concentration and was detected in the body part. Cd and Zn concentrations were generally low in all the samples when compared to the permissible limits stated by WHO while Pb and Fe concentrations were higher than the permissible limit in almost all parts of the samples.  It can be concluded that the contamination of Pb and Fe in the fish samples may pose a threat to human health. Advise is hereby given that fishes should be handled carefully and neatly to prevent the accumulation of heavy metals.