ASSESSMENT OF HEAVY METAL RESIDUES IN WATER, FLESH, GILLS AND LIVER OF Tilapia guineensis AND Clarias gariepinus FROM ELEYELE RIVER, IBADAN, NIGERIA

Industrialization and urbanization have brought about the contamination of river bodies, resulting in fish and other aquatic contamination. This study investigates the concentration of heavy metal residue such as in water, flesh, gills and liver of Tilapia guineensis (tilapia fish) and Clarias gariepinus (catfish) collected from the Eleyele river. Fifteen (15) water samples and three (3) fish samples of each specie were collected from five (5) different points along the Eleyele river, including: Oluseyi, Agbaje, Dam, Oba-Ido, and the ‘Save and Serve’ area. Three treated water samples were also collected from the Eleyele Water Corporation to serve as a control. The residue concentrations of heavy metals in the samples were analysed using Atomic Absorption Spectrophotometer (AAS). The concentrations of ranged from , ranged from ranged from ranged from ranged from 0.06±0.07 to 1.08±0.14. Significant differences in metal concentrations were identified across the various water sampling stations (p0.05) using analysis of variance. The highest and least values of metal residue concentrations obtained in the two fish species were 2.91±0.11 and 1.07±0.13 respectively. The results of metal concentrations in the gills and liver of catfish were in order of , while those of tilapia gills and liver were in the order of and respectively. The results of water samples, fish flesh and tissues exceeded the recommended values of standard organizations used as references. The minor differences in the results could be attributed to factors influencing metal uptake, such as age, feeding habits, geographic distributions, and species-specific factors. As a result, consumption of aquatic animals can cause acute and chronic diseases in humans and the animals that consume them.