Water Quality Assessment Based on Physicochemical Properties, Zooplankton Distribution and Composition of Owan River, Edo State, Nigeria

Abstract

With the increasing anthropogenic activities at Owan River, the suitability of the river for commercial and domestic activities deserves prominent attention. Hence, the objective of this paper was to investigate the physicochemical properties, zooplankton distribution and composition to assess the water quality of the Owan River, Edo State, Nigeria using standard methods. The zooplankton and water samples were collected from three (3) stations along the river and analysed at laboratory for taxonomic and diversity index. In the study, 18 taxa of Zooplankton comprising 32 individuals were encountered. The overall abundance was significantly higher (P > 0.05) in station 2 than in Stations 1 and 3 which were not significantly different (P < 0.05) from each other. Besides the Rotifers which were not found Cladocera and Copepods dominated low water level; contributed 53.13% and 46.87% by species and 37.50% and 18.75% relative abundance respectively. Among the Cladocera, Chydoridae and Cyclopoid Copepods were dominant in all the stations. There was no significant different (P <0.05) among the zooplankton encountered. Taxa richness (d) was highest at Stations 1 and lowest at Stations 3.  The general diversity (H) showed that station 1 had the highest diversity followed by station 2 and 3 respectively. The evenness index (E) showed that the maximum evenness was in station 3 and minimum in station 2. The analysis concluded that the river was not stressed beyond her carrying capacity, and did not exhibit harmful environmental conditions detrimental to commercial and domestic activities. Based on its physical, chemical characteristics and zooplankton diversity index, the Owan River was deemed suitable for such activities.