Article Title: Assessment of Heavy Metals (Zn, Pb, Cr and Cd) Levels in the Gill, Intestine and Flesh of Oreocromis niloticus and Liza grandisquamis obtained from Azuabie and Okujagu-Ama creeks in the Niger Delta, Nigeria.
The Azuabie and Okujagu-Ama creeks, are prone to pollution due to the discharge of industrial, domestic and abattoir wastes into the creeks. The aim of this study was to assess the level of some heavy metals (Zn, Pb, Cr and Cd) in the gill, intestine and fleshy tissue of Oreochromis niloticus and Liza grandisquamis obtained from the creeks. Fish Samples were analysed following the method of ASTM and determined using Atomic Absorption Spectrophotometery. Results indicated fish samples examined generally had elevated concentrations of heavy metals. In the gill and intestine of Orechromis niloticus, it was observed that Zn>Cr>Pb>Cd but in the fleshy tissue Zn>Pb>Cd>Cr but generally, Zn had the highest concentration in the different parts of the fish examined. Also, in the tissues of Liza grandisquamis, it was observed that generally, Zn>Cr>Pb>Cd. Though, individual metals varied in concentrations, the gill, intestine and flesh of both species of fish samples did not show significant difference (p>0.05) in their metal levels. The t-Test of significance for each metal between the two creeks was also not significantly different (P>0.05), implying that metal concentrations in fish from the two creeks were almost the same. It was however, noticed that the concentration of metals in fish from the creeks generally exceeded limits in sea food set by WHO, FAO and FEPA. Conclusively, there was gradual bioaccumulation and possible biomagnefication of heavy metals in fish from Azuabie and Okujagu-Ama creeks and this could be a risk for consumers of sea food from such presumed polluted areas.
Keywords: Heavy metals, Fish, Azuabie and Okujagu-Ama creek, Niger Delta