Heavy Metals Concentration in Sediment and Fish Samples from Owena Multi-Purpose Dam, Ondo State, Southern Nigeria

Abstract

Sediment samples taken from eight locations within the Owena Multi-purpose Dam in six sampling campaigns, covering the wet and dry seasons were analyzed for Pb, Cd, Cu, Cr, Ni, Fe, Mn and Zn using the atomic absorption spectroscopic method. Samples of three fish species: Clarias gariepinus, Clarias anguillaris and Oreochromis niloticus collected from the dam were also analysed for the above metals concentration. Results of heavy metals determination revealed significant seasonal variation (P = .05) in most measured parameters, while spatial variation was not significant. Generally, the results indicate that the measured parameters of the dam sediment were far lower than the Probable Effect Concentrations (PEC). Also, all metals monitored were detected in all the fish samples except cadmium that was not detected in the trunk of Oreochromis niloticus. They, however, showed values that were within the acceptable International Standards in fish for human consumption and so, could not presently cause any health hazard. The present study has produced vital information about the current status of the dam, which would also serve as a baseline for future monitoring of the dam. Sediment; heavy metals; Owena multi-purpose dam; fish; coefficient of variation