ABSTRACT

Various factors could impact the quality of water body such as tidal regimes, seasonal variations, Physico-chemical parameters and anthropogenic activities. This study aimed at assessing the distribution of Macrobenthic invertebrates of Osse River, Edo State was carried out at three stations from November 2020 to February 2021. The physical and chemical parameters analyzed were Air and Water temperatures, Flow-rate, pH, Depth, Dissolved oxygen, Biochemical oxygen demand, Iron and copper. These Physico-chemical parameters showed significant difference (p>0.05) in their values except depth which showed no significant difference (p<0.05) across the stations. Station 3 had the highest values for Air and Water temperature, flow-rate, and dissolved oxygen, Station 2 had the highest value for depth, transparency, while station 1 had the highest values for pH, biochemical oxygen demand, iron and copper. All macrobenthic invertebrates were identified to family level, a few species were observed. A total of 1004 individuals were recorded across the three study stations. Of these 4, 7, and 5 taxa were recorded in station 1, 2 and 3 respectively while the numbers of individuals were 220, 392 and 392 respectively. Ephemeroptera had a total of 892 individuals with Baetidae and Caenoidae being the most dominant of the group constituting 288 and 340 individuals respectively, Tricoptera constituted 112 individuals of the total macrobenthic invertebrates collected with polycentropodidae being dominant. No Plecoptera was found across the three study stations. The lowest taxa richness of individuals was recorded in station 1, while the highest was recorded in station 2. Evenness was highest at station 1. Station 2 had the highest value for general diversity. The overall comparison of members of the Ephemeroptera, Plecoptera, Trichoptera all had their P-value to be 0.0000, this signifies that there was high significant difference amongst the macrobenthic invertebrates from the study stations. The high diversity of macrobenthic communities is suggestive of low anthropogenic activities which resulted in less stress and abundance of sensitive species.