Ojija,Fredrick.Laizer, Hudson.2025-08-072025-08-072016-06-062277-8616https://repository.must.ac.tz/handle/123456789/420This Journal Article was Publish by IJSTRThis study was carried out to assess the water quality of Nzovwe stream using macroinvertebrates as bioindicators. Biological monitoring working party (BMWP) scoring system was the index used to assess the ecosystem health of Nzovwe stream. A total of 584 aquatic macroinvertebrates were identified from Nzovwe stream. They belonged to 22 families. The most abundant taxa were Odonata (35.959%), Hemiptera (25.514%), Coleoptera (18.493%), and Diptera (12.842%). Whereas the least abundant taxa were Ephemeroptera and Gastropoda, each constituting 1.028% of all macroinvertebrates. The most abundant macroinvertebrates were Dragonflies (27.226%), Water striders (13.185%), and Creeping water bugs (10.274%), whereas the least abundant were Giant water bugs (0.514%) and Backswimmers (0.514%). The BMWP score of Nzovwe stream was 115. Based on this score, the water of Nzovwe stream is neither very clean nor significantly altered aquatic environment. Hence the Nzovwe stream is moderately polluted due to non-point source pollution from several sources. Moreover, it was found that agricultural activities, washing and bathing could alter physico-chemical parameters of the stream and hence changing the abundance of macroinvertebrates as well as the quality of water. This study, therefore, recommends that the source of pollutants should be controlled and the stream regularly monitored by the relevant authorities. Additionally, biological indicators and their indices are suggested to be used in assessing the condition of a stream ecosystem.enArticle