Document Type : Primary Research paper
Department of Fisheries and Aquatic Sciences, Bahir Dar University
Streams are affected by different anthropogenic activities and often effects are reflected on the organisms living within these habitats. The response of organisms to stressors range from a decrease in abundance and diversity to the emergence of deformed structures. These responses of organisms are often used for stream health assessments. In this study, the incidence of Chironomus spp. muntum deformities was assessed to understand its potential use as a water quality indicator in Gerado and Abeyi streams in Sebeta town, Ethiopia. Chironomid and environmental data were sampled monthly from October 2016 to January 2017 at three sampling sites. The sampling sites were affected mainly by domestic activities and industrial effluents. The highest intensity of deformity (15%) was observed in GR1, a site affected by laundry activities, with TP 4.34±2.20mg/l, turbidity 32.1±9.44 NTU and conductivity 117.23±94.11 µS/cm followed by GR2 (12%) which receives effluents from the textile factory, with TP 29.29±9.58 mg/l, turbidity 50.8±40.62 NTU and conductivity 2518.00±2043.42 µS/cm. The least deformity was encountered in AB1 (9%), a site which was served as dumping of domestic wastes with TP of 4.10±1.86mg/l, turbidity 21.6±2.54 NTU and conductivity of 142.93±130.41 µS/cm. The frequency of deformity does not directly correspond with measured physicochemical parameters. Therefore, associating deformity with other factors like heavy metal measurements, the physical structure of the sediments, habitat type, feeding habit of the organism and geographical area are mandatory.