Biochemical Changes in Tilapia (Oreochromis niloticus) Exposed to Textile Effluents from Funtua Industrial Area, Katsina State, North West Nigeria

Industrial effluent pollution represents a growing threat to aquatic ecosystems and fish health in Nigeria's industrial corridors. This study investigated the biochemical alterations in Oreochromis niloticus exposed to sublethal concentrations of textile effluents collected from the Funtua industrial area in Katsina State, North West Nigeria. Ninety fingerlings were divided into five groups: a control receiving clean borehole water and four groups exposed to 10%, 25%, 50%, and 75% effluent dilutions for twenty-one days. Liver homogenates and whole blood were analysed for activities of superoxide dismutase, catalase, malondialdehyde, alanine aminotransferase, and aspartate aminotransferase at days seven, fourteen, and twenty-one. Effluent-exposed fish demonstrated concentration-dependent increases in malondialdehyde and hepatic enzyme activities, alongside significant depletion of antioxidant enzyme activities, indicating oxidative stress and hepatocellular damage. Fish at 75% effluent concentration exhibited the highest biochemical disruption and showed visible behavioural abnormalities including loss of equilibrium and reduced feeding. These findings demonstrate that sublethal textile effluent exposure induces measurable biochemical toxicity in Nile tilapia and support the application of fish biochemical parameters as biomarkers for water quality monitoring. Regulatory enforcement of effluent treatment standards in Katsina State is strongly recommended. Keywords: Oreochromis niloticus, textile effluent, oxidative stress, hepatotoxicity, Katsina.