Abstract

The detrimental effects of man on the aquatic environment are constant. In the Ogun River, Nigeria, four fish species Oreochromis niloticus, Malapterurus electricus, Parachanna obscura, and Chrysichthys nigrodigitatus were chosen for this study to assess the proximate composition and concentration of certain heavy metals. Atomic absorption spectrometry was used to examine the fish species for Manganese (Mn), Lead (Pb), Nickel (Ni), Cadmium (Cd), and Zinc (Zn). The fish species were gathered from the Abeokuta axis of the river. Utilizing accepted techniques, the moisture, crude protein, ash, and fat contents of the four fish species were examined. The findings showed that the four fish species had different rates of metal buildup. Only Oreochromis niloticus and Chrysichthys nigrodigitatus showed Pb and Mn traces, respectively. The liver and gills accumulated more metals than the muscles, with the exception of a few instances when Pb and Ni were found in the muscles of Oreochromis niloticus and Parachanna obscura, respectively. In every instance, the metal concentrations exceeded what was considered acceptable by international standards. While fat was the least abundant nutrient in all fish species (0.88-1.89 percent), all fish had high moisture contents of between 75 and 80 percent. The variations in proximal values between fish species were not noteworthy.