Indigenous Fish Diversity and Socioeconomic Importance in the Lower River Niger (Lokoja, Nigeria): Implications for Inland Fisheries Management and Aquaculture Development

Abstract

 Inland capture fisheries play a vital role in food security and rural livelihoods in Nigeria and also provide a foundation for aquaculture development through the supply of indigenous species. This study assessed the diversity, spatial distribution, and socioeconomic importance of indigenous fish species in the Lower River Niger at two fishing locations: Kpata and Ganaja Ferry sites in Lokoja. Fish species data were collected over a six-week period through direct sampling of artisanal fish catches, while socioeconomic information was obtained through structured interviews with fishers and fish traders. Species identification was carried out using standard taxonomic keys, and ecological indices including species richness, relative abundance, and Shannon–Wiener diversity were calculated. Economic importance was evaluated based on local demand, market price, and utilization patterns. A total of 15 indigenous fish species were recorded across both sites. Kpata had higher species richness (13 species) and abundance, dominated by Chrysichthys nigrodigitatus (138 individuals) and Oreochromis niloticus (120 individuals). In contrast, Ganaja Ferry site showed lower diversity and was dominated by Heterotis niloticus (45 individuals) and Clarias gariepinus (39 individuals). Spatial distribution analysis revealed site-specific species presence, with disturbance-tolerant species such as Silver Catfish and Nile Arowana dominating heavily trafficked areas. Shannon–Weiner diversity indices confirmed greater diversity and evenness at Kpata (H’=2.45, E=0.83) than at Ganaja Ferry (H’=1.58, E=0.63). Economic evaluation indicated that Nile Tilapia and African Catfish were of very high importance due to strong local demand and high market value (₦1500–7500/kg), whereas species such as Weather Loach and Grey Mullet were of minimal economic relevance. The results show that spatial variation in habitat characteristic strongly influence fish communities, and that resilient, economically valuable indigenous species continue to play a key role in food security and could support sustainable aquaculture development, providing baseline information for inland fisheries management in Nigeria.