STUDIES ON CONCENTRATION OF HEAVY METALS IN TISSUES OF FISH SPECIES (Clarias gariepinus and Oreochromis niloticus) IN LOWER RIVER NIGER AT GEREGU AJAOKUTA, KOGI STATE, NIGERIA

Abstract

 A study was conducted to assess of heavy metal concentrations in tissues (gills, viscera, and muscles) of Clarias gariepinus and Oreochromis niloticus from the Lower River Niger, Geregu Village. Sampling took place over three months (May-July) to evaluate spatial and temporal variations. Three sites along the River Niger at the location was marked for the samples collection and were designated as site A, B and C. The fish samples (muscle, gills and viscera) collected were digested and prepared for heavy metal analysis using Atomic Absorption Spectrophometer (AAS). Six heavy metals (lead, zinc, chromium, cadmium, iron, and nickel) were analyzed using AAS. The collected data were subjected to statistical analysis using Statistical Package for Social Sciences (SPSS, version 20). Results showed lead was the most prevalent in gill tissues across both species. However, all heavy metal concentrations were below recommended guidelines set by World Health Organization (WHO). The study's findings suggest the Lower River Niger's aquatic ecosystem is relatively unpolluted with heavy metals, ensuring the fish are safe for human consumption.