| Abstract: | Dense growths of macrophytes are a characteristic feature of chalk streams which may cause problems both to farmers and anglers. Weed is frequently cut to reduce flooding of surrounding land and provide open water for anglers. The objective of this study was to examine short-term responses of macroinvertebrate faunal assemblages in main flow and marginal samples to both weed-cutting and the application of herbicide and to compare these with untreated controls. No statistically significant effect could be demonstrated on such faunal parameters as biotic score, richness and abundance and a multivariate analysis of all available data showed that the weed-cut and herbicide treated sites could not be distinguished from the control sites III and V on the basis of their fauna. It is suggested that for conservation purposes small-scale management with ‘recovery strips’ separating the treated reaches can achieve the desired objectives of avoiding flooding and providing open water for anglers with minimal effects on the river biota. |
