Effects of the Macro-Invertebrates Community structure On the Quality of Surface Water in Enugu Urban, Enugu State, Nigeria

Abstract

The need for a robust understanding of macro invertebrates’ diversity can lead to specific management of surface water. This is essential due to frequent threats to aquatic ecosystem. The thrust of this study was to examine the water quality assessment using macro-invertebrates in surface waters in Enugu urban. In this study, 12 surface water samples were collected from the six major rivers in Enugu urban. Macro invertebrates were collected using semi-quantitative sampling techniques.The study spanned both the dry (February –early April) and the wet seasons, (late April to September). Nine (9) taxa comprising of 33 species belonging to Arthropod, Annelida and Mollusca were identified accounted for 1163 individuals. Increasing dominance of Macro-invertebrates followed the order: Mollusca (35%), Coeloptera (28%), Diptera (12.7%), Annelida (11.4%), Trichoptera (4.96%), Placoptera (2.78%), Ephemeroptera (3%), Hemiptera (0.85%) and Odonata (0.08%). The low number of macro-invertebrates and the dominant species (Melanoides, tuberculataandChironomussp.) being pollution tolerant suggest that the rivers especially Ekulu and Asata is relatively under stress. Species diversity indices showed a variation in the community structure in the rivers. Therefore, there is a need to regularly monitor and control the source of pollutants to the water bodies.