EFFECTS OF PHYSICO-CHEMICAL PARAMETERS ON THE DISTRIBUTION OF MACROPHYTES IN BIRNIN KUDU LOCAL GOVERNMENT, JIGAWA STATE, NIGERIA

ABSTRACT This study investigated the effects of physico-chemical parameters on the distribution of aquatic macrophytes in Kafin Gana Dam, located in Birnin Kudu Local Government Area of Jigawa State, Nigeria. Water and macrophyte samples were collected from three sites (inlet, middle, and outlet) to determine how variations in water temperature, pH, dissolved oxygen (DO), electrical conductivity (EC), total dissolved solids (TDS), turbidity, nitrate, phosphate, and biological oxygen demand (BOD) influence macrophyte abundance and diversity. Results showed discernible spatial variation in water quality, with nutrient levels (nitrate and phosphate), EC, TDS, and turbidity increasing progressively toward the outlet, while DO decreased downstream. Five dominant macrophyte species Eichhornia crassipes, Typha domingensis, Nymphaea lotus, Pistia stratiotes, and Ceratophyllum demersum were identified, with higher abundance recorded at nutrient-enriched sites. Correlation analysis revealed strong positive relationships between macrophyte abundance and nutrient levels (r = 0.88 for nitrate; r = 0.91 for phosphate), while DO showed a negative relationship (r = –0.68), indicating oxygen depletion in areas with dense vegetation. The findings demonstrate that nutrient enrichment and ionic concentration are major drivers of macrophyte proliferation in the dam, signaling moderate eutrophication. The study concludes that anthropogenic activities contribute significantly to water quality changes, influencing macrophyte distribution. It recommends regular monitoring of water quality, control of agricultural runoff, and the management of invasive species to promote ecological balance and sustainable use of the dam ecosystem.