'n Limnologiese evaluering van waterhulpbronne by Kragbronkragstasies

Abstract

Water resources associated with coal driven power stations are usually exposed to various sources of pollution and anthropogenic stress. With increasing public awareness and stricter environmental legislation, the restoration of all disturbed areas under the control of Power Stations to a point where they satisfy the major ecological norms has become an important aspect of their environmental management strategy. The closure of such sites and the subsequent rehabilitation of these areas makes it imperative that the end use of these sites and water resources must be defined and that the quality of water resources must be described in order to evaluate any possible risk in utilising these resources. The main aim of this study was therefore to describe the species composition and diversity of aquatic fauna associated with the water resources at the two KRAGBRON Power Stations and to identify the relationships between water quality and species composition of aquatic invertebrates. Water from the study dams and nearby pans showed a range of water quality types and characteristic aquatic invertebrate communities were shown to be associated with each of these water resources. Significant differences in species diversity between the study dams and pans were determined. The positive role of reed beds in water purification was related to an increase in species diversity. The negative effect of ash deposits in water on the aquatic invertebrate fauna was shown. The results from this study provide a basis for recommendations for the use and further rehabilitation of these sites and provide reference data for further impact studies on aquatic fauna.