A Survey of Fish Species Abundance and Distribution in Komadugu Yobe River

Komadugu Yobe River is a vital freshwater ecosystem in North-Eastern Nigeria, supporting the livelihoods of thousands of fishermen and contributing significantly to regional food security. Despite its economic importance, comprehensive data on fish species composition, abundance, distribution, and water quality parameters along the river's full length have been lacking hence informed this study. Ten sampling locations were established at 20 km intervals along the river from upstream to downstream. Monthly data collection was conducted over a 12-month period. Fish were captured using different fishing gears appropriate for different water depths and foraging behaviors. Water quality parameters were measured onsite and through laboratory analyses following standard methods. Fish species were identified using taxonomic keys, enumerated, and weighed. Data were analyzed using ANOVA, diversity indices (Shannon-Weiner and Simpson), and percentage abundance calculations. A total of 260,674 individual fish (biomass: 80,643.04 kg) belonging to 13 families and 29 species were recorded. Cichlidae and Mormyridae were the most species-rich families (5 species each). Shannon-Weiner diversity index (H'=2.19) and Simpson diversity index (D=0.80) indicated high species diversity. Alestes nurse dominated numerically (17.89%), while Clarias gariepinus contributed the highest biomass (13.45%). Water quality parameters remained within optimal ranges for tropical fish species with no significant spatial variations (P>0.05). The Komadugu Yobe River supports a diverse and evenly distributed fish community, attributable to stable and favorable physicochemical conditions throughout its length. Three species (Barilius senegalensis, Clarias spp., and Tetraodon fahaka) showed evidence of decline and require conservation attention. These findings provide essential baseline data for sustainable fisheries management and biodiversity conservation in the region.