Variation of benthic fauna composition in river Benue at Makurdi, Benue State, Nigeria

Abstract

Macro benthic fauna ofrnRiver Benue at Makurdi, Benue State Nigeria was studied for two years from Julyrn2011- June 2013 at five sampling stations along the river course. Sedimentsrnsamples were collected monthly using Van Veen Grab and analyzed for thernpresence of macro benthic fauna at the five different sample stations. Thernresult of the sediments showed that a total of 4,451 macro benthic faunarnindividuals comprising of 4 phyla and 21 taxa were obtained. More individualsrnwere recorded during the dry seasons as compared to the rainy seasons. Benuernbrewery (570, Individuals) and Mikap Nigeria Ltd (649 Individuals) recorded lowrnpopulation as compared to the other locations: Coca cola (1,177 Individuals),rnWadata market (1,043 Individuals) and Wurukum abattoir (1,012 Individuals).rnAthropoda had the highest population of individuals as compared to Annelida,rnMollusca and Platyhelminthes. Mosquito larvae was determined with the highestrnrelative abundance of 10.8% throughout the period of the study at Wadata marketrnwhile the lowest relative abundance of 0% was observed for Stone fly and Mayrnfly at Benue brewery and Mikap Nigeria Ltd stations throughout the period.rnThere was generally low biodiversity of benthic fauna community which indicaternthe perturbed nature of the study area. Diversity indices result showed a variationrnin the community structure of River Benue. It is recommended that therndischarged of effluents and other waste into the River Benue should berncontrolled and enforced.