Water quality and physiological stress biomarkers in selected fish species from Benue Cement Dam, Gboko, Nigeria

This study assessed surface water quality using NESREA (2011) standards and fish functional responses in Benue Cement Dam, Gboko, Nigeria. Water temperature (26.08–29.08 °C) and pH (6.17–7.62) were within permissible limits, whereas total hardness, alkalinity, chloride, and ammonia nitrogen were above guideline values. Haematological parameters showed significant alterations, including high haemoglobin concentrations and notably increased white blood cell counts across fish species and seasons, indicating physiological stress. Substantial increases in enzyme activities (ALP, AST) and oxidative stress biomarkers (SOD, CAT, GR, MDA, GPx; p < 0.05–0.001) further confirmed oxidative imbalance and effect on fish health. The findings suggest that damming and various industrial activities in the area have reduced water quality and induced stress in inhabiting fish populations. Haematological and oxidative biomarkers as practical tools for aquatic ecosystem monitoring have indicated the need for stricter pollution control and sustained biomonitoring efforts.