Induction of oxidative stress and DNA damage in two common fish species of rivers and reservoirs in Ilorin, Northcentral, Nigeria

Abstract

Rivers and reservoirs around the world are becoming dumping sites for liquid and solid wastes which are toxic to the fish. The physicochemical parameters and ecotoxicological potential of fish species in Ilorin's major rivers and reservoirs were investigated. Water and fish samples were collected from five sites: Unilorin Reservoir (A), Apodu Reservoir (B), Asa Reservoir (C), Asa River (Harmony) (D), and Asa River (Unity) (E). Excluding rivers (D and E) with low dissolved oxygen (DO) and a slight increase in lead (Pb), all physicochemical parameters were within the NSDWQ and WHO criteria for drinking water. Fish samples at D and E showed changes in the serum biochemical and haematological profiles and induction of micronuclei (MN), nuclear abnormalities (NA) and DNA single-strand break. Antioxidant enzymes were also increased in the fish. Our findings show that water from D and E can cause cytogenotoxic in fish due to hypoxic conditions triggered by Pb. This study will provide valuable health risks and future river water treatment strategies.

Keywords

• Rivers
• reservoirs
• genotoxicity
• oxidative stress
• Tilapia zillii
• Clarias gariepinus