A mystery surrounds the spraying of the hyacinth on the Hartbeespoort Dam by a helicopter on Thursday, 3 December, with no one taking responsibility so far.
Upon enquiries by Kormorant, the North West Department of Economic Development, Environment, Conservation and Tourism (DEDECT) indicated that they were not aware of the spraying. A spokesperson of the Department of Water and Sanitation (DWS), that has the authority over the dam and must give permission for such activities, said on Wednesday that according to information, the spraying was done by private parties. “The DWS as custodian has requested the Department of Environment, Forestry and Fisheries (DEFF) to follow up on the matter as there was no such request made,” said DWS spokesperson, Sputnik Ratau.
In the meantime the Centre for Biological Control at Rhodes University, that has been using biological control on the hyacinth, said in a statement that the application of herbicide on the dam was done without their knowledge and was not endorsed by the organisation,
“The use of herbicide to control water hyacinth is an effective and important tool for managing water hyacinth, however, over-reliance on herbicide to manage aquatic weeds does come with risks, which may include changes in water quality, the potential for algal bloom, and negative effects on the biocontrol agents (insects on the hyacinth),” the CBC said in a statement this week.
“The weevils on the hyacinth, whose larval stages exist within the plant and cannot escape when the plants sink, are most affected by the herbicide applications. Furthermore, extensive herbicide sprays place the dam back on the herbicide-treadmill, whereby constant spraying is required to maintain the plants as the biocontrol agent populations become constantly reduced.”
(Anyone with information about the spraying can contact Kormorant on 072 953 0071.)