Details

Autor(en) / Beteiligte

• Gumede, Sabelo Victor

Titel

Assessment and Management of the Impact of Platinum Mining on Water Quality and Selected Aquatic Organisms in the Hex River, Rustenburg Region, South Africa

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

2012

Link zum Volltext

• ProQuest

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• Mining operations significantly influence the environment due to direct and indirect discharges of waste products into the aquatic systems. The primary aim of this study was to assess the current situation in the platinum mining area and develop a management plan to ensure that existing and potential environmental impacts caused by platinum mining and processing are mitigated.To do this, an assessment was carried out to investigate changes in critical aquatic invertebrate and fish community distributions and assess how they relate to measured environmental factors. Five sites were selected, one reference site which is upstream of heavy mining activities and four sites within heavy mining and processing activities. Standard techniques for water, sediment, invertebrate and fish sampling were used. Macro-invertebrates sampled were identified to family level whereas fish were identified to species level.Multivariate analysis used was cluster analysis by non-metric multidimensional scaling (NMDS) for both macro-invertebrates and fish. Three methods of ordination were used to analyze the biotic and abiotic data namely N-MDS, Correspondence Analysis (CA) and Canonical Correspondence Analysis (CCA).Cluster analysis of macro-invertebrates data revealed three major groups based on sampling period (low flow or high flow) and the last cluster according to the locality. Multidimensional scaling ordination of high and low flow for macro-invertebrate communities confirmed the groupings detected by cluster analysis. Cluster analysis for fish communities revealed two groups at 50% similarity; the first group is the combination of reference and exposure sites for both high and low flow sampling regimes. No fish were sampled at site 4 during both low and high flow regimes. Multidimensional scaling ordination of high and low flow fish communities confirmed the groupings detected by cluster analysis. Analysis using a similarity profile (SIMPROF) test indicated that fish communities are statistically (p=5%) the same. It was found that macro-invertebrates and fish respond differently to environmental variables. The macro-invertebrate and fish community structure indicated no clear-cut distinction between exposure and reference sites. CCA indicated that metals in sediment and water appear to have a stronger relationship with macro-invertebrate community structure than fish community structure. On the other hand, the metal accumulation in fish liver and muscle tissue did not show any relationship with the environmental variables. Similarity percentages (SIMPER) for cluster analysis was used to determine indicator species to the trend and this revealed that Tabanidae, Oligochaeta and Corixidae were the major contributors to the separation of macro-invertebrate groups which are pollution tolerant families. It was found that macro-invertebrate community distribution is influenced more by contaminants in the sediment than sediment particle size. Furthermore, it was found that that non-core mining activities negatively affect the fish communities of the Hex River. The results indicated that site four is highly impacted by mining activities in terms of water and sediment quality.The study was thus able to provide data and co-ordinate resources towards the development of the management plan to ensure that changes in the macro-invertebrate and fish community distributions due to water and sediment qualities are detected in time and mitigation measures put in place. It is expected that a management plan will be used to conduct the Hex River rehabilitation process, which is a commitment in the Environmental Management Programme Report (EMPR) for Rustenburg Platinum Mines (RPM).