Heavy Metals and Physico-Chemical Properties of Clarias Gariepinus from Five Water Bodies in South East Nigeria

This study was conducted to evaluate the concentration of lead (Pb), copper (Cu) and zinc (Zn) of clarias gariepinus from three rivers (Uwana, Oziza, Akpoha,) and two aquaculture fish farms (PolyUwana and Ngwo) in the south-eastern part of Nigeria. Samples of fish species and water were obtained in triplicates from fishermen and aquaculture sellers. The fish samples were digested and analyzed. The physico-chemical properties of the water samples were also determined. The result showed that Pb concentrations (ppm) in the fish samples were 0.000 ± 0.001 (Uwanariver), 0.014 ± 0.041 (Ngwo), 0.022 ± 0.026 (Akpoha river), 0.043 ± 0.057 (Oziza river) and 0.047 ± 0.063 (PolyUwana). Cu concentrations were 0.020 ± 0.027 (Uwana river), 0.028 ± 0.026 (Oziza river), 0.029 ± 0.023 (PolyUwana), 0.038 ± 0.021 (Ngwo) and 0.048 ± 0.071 (Akpoha river). Zn concentrations were 0.366 ± 0.178 (Uwana river), 0.458 ± 0.323 (PolyUwana), 0.467 ± 0.356 (Akpoha river), 0.486 ± 0.245 (Oziza river) and 0.492 ± 0.161 (Ngwo). There were significant (p < 0.05) differences between the river sources for Pb. There was no significant difference between the river sources for Zn and Cu. The physicochemical properties of the water showed low levels of the elements studied and the highest concentration of metals was in Oziza river while the lowest concentration was in Ngwo Aquaculture. There were no significant (p> 0.05) differences in Pb, Cu and Zn concentrations of the water samples. Water sample from Oziza river was also found to have the highest turbidity (15.20), highest titrable acidity (0.95) and lowest pH (5.47). In all cases, the heavy metal concentrations were lower than the maximum limit set by FAO/WHO.