Macroinvertebrate-based index of biotic integrity for assessing the ecological condition of Lake Wanchi, Ethiopia

Abstract

Background : Lake Wanchi is one of the Ethiopian lakes that have huge ecological, socio-economic and aesthetic value. This study was conducted to assess the ecological condition of Lake Wanchi using the macroinvertebrate-based index of biotic integrity between September 2016 and should 2017. Methods : Four sampling sites (LWS 1, LWS 2, LWS 3, and LWS 4) were purposively selected. A rapid bioassessment protocol criterion was accustomed to categorize the sites. About 1249 macroinvertebrate individuals were collected using the D-frame net with a mesh size of 500µm. Physico-chemical analysis was also done to assess the link between the benthic macroinvertebrate structure and environmental factors within the system. Results : The benthic index of biotic integrity ranged from 12.54 to 100 and also the sites were categorized into three quality ranks: LWS 1 and 3 as fair, LWS 2 as good, and LWS 4 as very good.  Conclusions : The study confirmed that Lake Wanchi was largely influenced by agricultural and other anthropogenic factors. This study concluded that the benthic index of biotic integrity is an appropriate tool for water quality and ecological assessment in the lakes.