Evaluation of African Manatee Trichechus senegalensis habitat quality and abundance along Lower Benue River Nigeria

Abstract

This study evaluated the status, perceived abundance, distribution, and habitat suitability of the African manatee (Trichechus senegalensis) along selected sections of lower River Benue basin, Nigeria, using an integrated approach. Data were collected through, physico-chemical water quality assessment, structured questionnaires, and community ecological knowledge. Physico-chemical parameters varied significantly among sites (p < 0.001) but were generally within ranges suitable for aquatic vegetation and manatee habitat, with Gbajimba exhibiting the most favourable conditions. Community surveys (n = 100) indicated high awareness of manatees (70–90%) across all communities, though reported sightings were infrequent, suggesting low-density and cryptic populations. Chi-square analysis showed no significant differences (p > 0.05) among communities in awareness, sightings, seasonal occurrence, or perceived population trends. Focus group discussions identified Gbajimba as having the highest perceived abundance, while Makurdi, Agatu, and Abinshi were characterized by low or declining populations. Calm waters, abundant aquatic vegetation, deep pools, and shelter were consistently identified as preferred key habitat features. Major threats included habitat degradation, sand mining, hunting, pollution, incidental capture in fishing gear, and boat disturbance. Habitat suitability analysis classified Gbajimba as highly suitable, Makurdi and Agatu as suitable, and Abinshi as moderately suitable. The findings confirm the continued but uneven presence of Trichechus senegalensis along the lower River Benue basin and highlight the need for habitat protection and non-visual monitoring approaches, such as passive acoustics and environmental DNA, to support effective conservation.