Assessment of the Biochemical and Genotoxic Effects of Ecologically Relevant Concentrations of Nickel in Clarias gariepinus (Burchell, 1822)

Abstract

This study was aimed at determining the biochemical and genotoxic effects of ecologically relevant concentrations of Nickel (Ni) in Ologe Lagoon; which constitutes its originality. An initial field study was conducted to determine the concentrations of some heavy metals (arsenic, nickel and lead) in surface water, sediments, and fish from Ologe Lagoon. Ten fish per test concentration were used for the bioassay. Oxidative stress indicators (superoxide dismutase, catalase, reduced glutathione and malondialdehyde), and nuclear abnormalities were assessed in fish chronically exposed to ecologically relevant concentrations of Ni. Environmentally relevant concentrations of Ni did not have any significant effects on the levels of reduced glutathione, catalase, superoxide dismutase and malondialdehyde after 30 days of exposure. Similarly, Ni had no significant effects on all tested parameters of genotoxicity after day 30. Therefore, environmentally relevant concentrations of Ni in Ologe Lagoon may not have any deleterious effects in terms of oxidative stress and genotoxicity.