title: Macroinvertebrate assemblages in agricultural, mining, and urban tropical streams: implications for conservation and management.
abstract: The study evaluated the response of macroinvertebrate assemblages to changes in water quality in different land-use settings in Manyame catchment, Zimbabwe. Four land-use categories were identified: forested commercial farming, communal farming, Great Dyke mining (GDM) and urban areas. Macroinvertebrate community structure and physicochemical variables data were collected in two seasons from 41 sites following standard methods. Although not environmentally threatening, urban and GDM areas were characterised by higher conductivity, total dissolved solids, salinity, magnesium and hardness. Chlorides, total phosphates, total nitrogen, calcium, potassium and sodium were significantly highest in urban sites whilst dissolved oxygen (DO) was significantly higher in the forested commercial faming and GDM sites. Macroinvertebrate communities followed the observed changes in water quality. Macroinvertebrates in urban sites indicated severe pollution (e.g. Chironomidae) whilst those in forested commercial farming sites and GDM sites indicated relatively clean water (e.g. Notonemouridae). Forested watersheds together with good farm management practices are important in mitigating impacts of urbanisation and agriculture. Strategies that reduce oxygen-depleting substances must be devised to protect the health of Zimbabwean streams. The study affirms the wider applicability of the South African Scoring System in different land uses.
authors.affiliation: School of Wildlife, Ecology and Conservation, Chinhoyi University of Technology, Off Harare-Chirundu Rd, P. Bag 7724, Chinhoyi, Zimbabwe. mrmwedzi@gmail.com.
authors.forename: Tongayi
authors.initials: T
authors.lastname: Mwedzi
authors.affiliation: School of Wildlife, Ecology and Conservation, Chinhoyi University of Technology, Off Harare-Chirundu Rd, P. Bag 7724, Chinhoyi, Zimbabwe.
authors.forename: Taurai
authors.initials: T
authors.lastname: Bere
authors.affiliation: School of Wildlife, Ecology and Conservation, Chinhoyi University of Technology, Off Harare-Chirundu Rd, P. Bag 7724, Chinhoyi, Zimbabwe.
authors.forename: Tinotenda
authors.initials: T
authors.lastname: Mangadze
mesh_terms: D000383:Agriculture; D000818:Animals; D059001:Aquatic Organisms / Q000502:physiology*; D058448:Biota; D003247:Conservation of Natural Resources; D016468:Forestry; D007448:Invertebrates / Q000502:physiology*; D008906:Mining; D045483:Rivers / Q000737:chemistry*; D012621:Seasons; D014507:Urbanization; D060753:Water Quality; D015030:Zimbabwe
keywords: Dissolved oxygen; Forested watershed; Land-use; SASS; Water quality