Biological monitoring and pollution assessment of the Mukuvisi River,Harare, Zimbabwe

The ecological health and biodiversity of the Mukuvisi River system were investigated during this brief study to assess the functioning of the natural river system, utilizing biological monitoring. The study covered a period of 5 weeks from 15 September to 12 October 2005, during which a weekly sampling routine was conducted, and the effects of pollution on the river were investigated. The pH, dissolved oxygen concentration, temperature and electrical conductivity, as well as the two major nutrients in the water (phosphorus; nitrogen) were measured at four sites along the Mukuvisi River. Macroinvertebrate species also were identified and enumerated at each site, using the South African Scoring System version 4 (SASS4) to assess the biological diversity and to evaluate pollution levels at each site. Site 2 was the most polluted, while site 4 was the cleanest site. It was concluded that, although the river receives pollutants along its course, it also has a self‐purification capacity that can be enhanced by remedial measures against pollution. Possible remedial actions are discussed as recommendations in this study.