ABSTRACT
Aquatic environments face increasing contamination from various pollutants, leading to the gathering of heavy metals in fishes, crucial for the nutrition of billions worldwide. This study examined the concentration and distribution of heavy metals (Fe, Zn, Cu, Pb, and Cd) in six fish species (Hemichromis fasciatus, Oreochromis niloticus, Oreochromis aureus, Synodontis nigrita, Brycinus macrolepidotus, and Chromidotilapia guntheri) from Ikpoba river. Results revealed significant variability in metal concentrations across the species. Hemichromis fasciatus exhibited the highest iron concentration (4.032±1.893 mg/kg), with a range of 2.693-5.370 mg/kg, while Oreochromis niloticus showed the lowest (0.158±0.036 mg/kg) with minimal variability (0.132- 0.183 mg/kg). Zinc levels varied widely, with Oreochromis aureus displaying the widest range (0.204-0.348 mg/kg) and Hemichromis fasciatus the narrowest (0.067-0.200 mg/kg). Synodontis nigrita had the most of copper concentration (0.122±0.035 mg/kg), with a broad range (0.097- 0.147 mg/kg), while Hemichromis fasciatus had the lowest and least variable levels (0.037±0.006 mg/kg). Lead content was highest in Oreochromis aureus (0.015±0 mg/kg), exhibiting the widest variability, and lowest in Chromidotilapia guntheri (0.007±0 mg/kg), with the narrowest range. Cadmium levels were most pronounced in Brycinus macrolepidotus (0.01±0.004 mg/kg) with significant variability, while Chromidotilapia guntheri had the lowest (0.005±0.006 mg/kg). The findings contribute valuable insights into the pattern of distribution of heavy metals in fish populations, with emphasis on the vitality of continued surveillance and management plans to reduce environmental pollution and preserve public health.
