Assessment of Water Quality Parameters of Zobe and Ajiwa Reservoirs, Katsina State, Nigeria

A seven month study was carried out between August 2020 and February 2021, to assess the physicochemical parameters of Ajiwa and Zobe reservoirs in Katsina State, Nigeria, with a view to understanding the pollution status of the water bodies. Selected water quality parameters were assessed using standard methods, these include temperature, pH, dissolved oxygen (DO), hardness, turbidity, alkalinity and ammonia-nitrogen. The parameters were compared between the two water bodies using independent sample t-test, while Pearson correlation analysis was used to examine the interdependence among the water quality parameters. Temperature and transparency were higher in Zobe reservoir 24.14+0.77 °C and 8.36+0.12 cm respectively than in Ajiwa reservoir 23.13+0.74 °C and 7.37+0.11 respectively. DO, pH, Alkalinity, ammonia-nitrogen and hardness were all higher in Ajiwa reservoir, although none of the parameters was different significantly between the two water bodies (P>0.05). However, they were all within the recommended level for optimum performance of tropical fish species, except ammonia-nitrogen that was consistently higher than 1 mg/L. There were variations in the water quality parameters across the months. Temperature and ammonia-nitrogen were higher during the rainy season between August and October, then decline afterwards through the harmattan cold season. Transparency, DO,pH and hardness had their least during the rainy season, then rose gradually to peak in February. Some of the water quality parameters showed interdependence among each other with either negative or positive significant correlations. It is safe to say the water bodies are not polluted, however, the ammonia-nitrogen level deserves attention to prevent sub-optimal living of the fishes and other aquatic organisms in the water bodies