CSIR Natural Resources and the Environment, P.O. Box 395, Pretoria, 0001, South Africa; Department of Genetics, University of Pretoria, Hillcrest, Pretoria ZA002, South Africa; Department of Microbiology and Plant Pathology, University of Pretoria, Hillcrest, Pretoria ZA002, South Africa
Oberholster, P.J., CSIR Natural Resources and the Environment, P.O. Box 395, Pretoria, 0001, South Africa; Botha, A.-M., Department of Genetics, University of Pretoria, Hillcrest, Pretoria ZA002, South Africa; Cloete, T.E., Department of Microbiology and Plant Pathology, University of Pretoria, Hillcrest, Pretoria ZA002, South Africa
Macroinvertebrate communities in Rietvlei nature reserve wetland area and their relationship with water quality were studied with the aim to evaluate their use as potential indicators of pollution. Sampling locations were selected to include outlets from swage effluent, agricultural and informal residential runoff. A large increase in nutrient concentrations was observed downstream from discharged treated sewage with an associated decrease in species richness. Bioassays performed included: Daphnia magna, Hydra attenuate, Lactuca sativa, Allium cepa and Pyxicephalus adspersus. The highest percentage of lethality response to a screen (100% concentration) of sampled wetland water by test specimens were observed at the point source input of the Hartbeespoort treated sewage plant. Data generated from the AUSRIVAS method and multitrophic level bioassays revealed the deterioration of the wetland possibly due to factors such as increasing urbanization, industrialization, agriculture runoff and rapid human settlement in the Hennops River catchment area and its principal tributaries. © 2008 Elsevier Ltd. All rights reserved.
Agricultural runoff; Automation; Catchments; Concentration (process); Effluents; Oil spills; Pollution; Reusability; River pollution; Rivers; Sewage; Water quality; Wetlands; Allium cepa; AUSRIVAS; Chemical evaluation; Daphnia magna; Lactuca sativa; Macroinvertebrate communities; Multitrophic level; Multitrophic level bioassay; Nutrient concentrations; Peat bog; Point sources; Potential indicators; River catchments; Sampling locations; Sewage waters; South Africa; Species richness; Test specimens; Treated sewage discharge; Wetland area; Water pollution; runoff; agricultural runoff; bioassay; biological analysis; catchment; chemical analysis; community response; industrialization; macroinvertebrate; nutrient; peatland; sewage; sewage treatment; species richness; tributary; urbanization; water pollution; water quality; wetland; agriculture; analytic method; article; AUSRIVAS method; Australia; bioassay; catchment; chemical analysis; coelenterate; concentration response; Daphnia; deterioration; Hydra attenuate; industrialization; lettuce; macroinvertebrate; nonhuman; nutrient concentration; onion; Pyxicephalus adspersus; river ecosystem; sewage effluent; source point; South Africa; species richness; urbanization; water pollution; water quality; wetland; Biological Assay; Ecosystem; Environmental Monitoring; Eutrophication; Fresh Water; Nitrogen; Phosphorus; Sewage; South Africa; Waste Disposal, Fluid; Water Pollutants, Chemical; Water Pollution; Wetlands; Africa; Gauteng; Rietvlei Nature Reserve; South Africa; Southern Africa; Sub-Saharan Africa; Allium cepa; Daphnia magna; Hydra; Lactuca sativa; Pyxicephalus adspersus