The environmental quality and macroinvertebrate community structures of wetlands found in the Lake Tana Watershed, Ethiopia

Abstract

The present study was conducted to assess the environmental quality status and macroinvertebrate community structures of wetlands using macroinvertebrates as bioindicators. A multimetric biotic index approach was used for the study. The findings revealed 3,367 macroinvertebrates belonging to 37 families. The percentages of Ephemeroptera, Odonata, and Tricoptera (%EOT), percent Diptera, percent filterercollectors, the ratio of Ephemeroptera, Plecoptera, and Trichoptera to Chironomid (EPT/C), the Biological Monitoring Working Party Score, and the Shannon–Wiener diversity index were all significantly related to human disturbance and could be used to assess water quality. Based on the macroinvertebrate index, human disturbance had a significant impact on Shesher wetland, a relatively lower impact on Avaji and Yitamot, and a moderate impact on Chimba, while Dena and Wonjeta had good habitat quality. Their water quality was very poor, poor, moderate, and very good, in that order. Farming, leather tanning, waste dumping, and effluent discharges were responsible for the poor habitat quality of impacted wetlands. Therefore, unless managed properly, human disturbance activities in the wetlands catchment were threatening macroinvertebrates and the wetlands ecosystem. Hence, implementation of catchment-based management together with continuous health status monitoring and a standalone wetland policy should be established.