Responses of macroinvertebrate traits to agricultural activities: a case study of a rural river in North-central Nigeria

Globally, macroinvertebrate trait-based approaches have been utilised to assess environmental vulnerabilities due to the potential information they provide about the mechanisms underlying the dynamics in their community structure. In this study, we explored the responses of macroinvertebrate traits to agricultural activities in River Wanzum, North-central Nigeria. Macroinvertebrates and water were sampled from four sampling stations using standard methods for 24 months (December 2021 and November 2023). Five traits (feeding habit, respiration, body size, body form/shape and mobility) were selected to assess the level of functional deterioration occurring at the sampling stations. From the RLQ model we constructed, the first and second RLQ axes eigenvalues are 0.69322 and 0.29527, and the cumulative projected inertia is 64.98% and 92.66% for axes 1 and 2, respectively. Macroinvertebrate traits, such as collector-filtering, shredding feeding habit, spherical body shape, gill form of respiration, medium body size, large and very large body size organisms, were associated with stations 1 and 4 subjected to less agricultural activities. The fourth corner analysis revealed a negative relationship between COD and taxa that use collector-filtering feeding habits. Overall, we conclude that a trait-based approach can provide ecologically based information with predictive responses by developing relationships between traits and environmental factors.