Assessment of Water Quality of Kware Lake Using Aquatic Insects as Bioindicators

Abstract

Water quality of Kware Lake was assessed through the abundance of aquatic insects as indicators from April to September, 2016. Samples of aquatic insects were obtained from the lake with a dip-netby dipping on monthly basis at four designated sampling stations. The insect samples collected were sorted in the laboratory and identified to order and family levels using aquatic insects' taxonomic keys. The results generated ware used to calculate insect abundance and biotic index for water quality. Standard methods of analyses were used for analyzing the physicochemical status of the water samples collected from the Lake. Pearson's Correlation was employed to relate between the abundance of insects and physicochemical parameters of water from the Lake. A total of 878 insects representing 26 families from 5 orders were observed. The bioticindex calculated for the families of Coleoptera, Diptera, Ephemeroptera, Hemiptera and Odonata were 1.11, 1.20, 1.50, 1.11 and 1.14 respectively indicating excellent water quality. Analyses of physicochemical parameters showed variable ranges and some differ in concentrations among periods of sampling but the pH, turbidity, NO_3, and PO₄were found to have significant correlation (P> 0.05) with the abundance of the insects. Measures of controlling negative human activities around the lake need to be enforced.