SUMMARY
As a result of eutrophication studies that have been performed by the National Institute for Water Research for many years it was decided in 1980 that a detailed investigation into this area take place. Hypertrophic Hartbeespoort Dam was selected as the study site. A simulation model, named TROFIC, of the ecosystem was developed and updated over a three-year research program. Different management strategies were performed to attempt to reduce the size of phytoplankton standing stock and to modify the phytoplankton species composition so that blue-green algae are no longer dominant. In this paper the applicability of each strategy to the model is examined by means of results obtained and conclusions drawn from these results.