Physicochemical Parameters of Water Quality at Some Selected Sections of the Gongola River Continuum.

Abstract

Water quality is a fundamental determinant of aquatic ecosystem health and human well-being, yet it is increasingly threatened by anthropogenic and natural pressures. This study assessed the physicochemical parameters at some selected sections of the Gongola River continuum, northeastern Nigeria, to evaluate spatial and temporal variations in water quality and ecological implications. Four sampling stations: Wuyo (upstream), Dadinkowa (midstream below dam), Malleri (agriculturally influenced), and Kupto (downstream) were selected to represent the longitudinal profile of the river. Fortnight sampling was conducted between January and December 2024, and parameters measured included air and water temperatures, turbidity, pH, total dissolved solids (TDS), electrical conductivity (EC), dissolved oxygen (DO), biochemical oxygen demand (BOD), nitrate, and phosphate. Standard methods of the American Public Health Association (APHA, 2023) were applied, and data were analyzed using analysis of variance (ANOVA) with post hoc least significant difference (LSD) tests. Results revealed minimal spatial variation across stations, with most parameters within acceptable limits for freshwater ecosystems. Mean DO concentrations (7.98–8.17 mg/L) indicated a well-oxygenated system, while BOD values (3.66–3.73 mg/L) suggested low organic pollution. Nitrate (1.30–1.48 mg/L) and phosphate (0.88– 0.98 mg/L) concentrations were low, reducing the risk of eutrophication. Although uniformity in physicochemical parameters suggests effective natural self-purification and integrated hydrological processes, continuous monitoring is required to mitigate cumulative impacts of agriculture, effluents, and dam regulation. This study provides essential baseline information for the management of the Gongola River and highlights the need for integrated watershed management to sustain water quality, fisheries, and community livelihoods.