Bioaccumulation of Heavy Metals in Water Column, Sediments, and Tissues of Silver Catfish (Chrysichthys nigrodigitatus) and Nile Tilapia (Oreochromis niloticus) Collected from Sagbo Koji Riverine Community, Lagos Island, Southwest Nigeria

This study investigates the bioaccumulation of heavy metals in two commercially important fish species, Silver Catfish (C. nigrodigitatus) and Nile Tilapia (O. niloticus), as well as in the water and sediment of Sagbo Koji, a riverine community within Lagos Island, Nigeria. Samples of water, sediment, and fish tissues were collected from three stations over an eight-week period. Concentrations of nine heavy metals (Fe, Zn, Pb, Cu, Mn, Ni, Cr, Cd, and Co) were analyzed using Inductively Coupled Plasma-Optical Emission Spectrometry (IC-OES). Results revealed that most metals exceeded WHO/FEPA permissible limits in fish tissues, water, and sediments. C. nigrodigitatus accumulated higher levels of metals compared to O. niloticus, with Fe and Zn being the most abundant in both species. Bioconcentration Factor (BCF) analysis showed significant uptake of metals from both water and sediment, with Fe and Pb displaying the highest BCFs. The findings underscore the ecological and public health risks posed by anthropogenic pollution in the area and highlight the need for improved environmental monitoring and regulation.