Changes in Plant community at Foxcote Reservior Following Use of Ferric Sulphate to Control Nutrient Levels

Abstract

SYNOPSISIn an attempt to control planktonic algal growth in In an attempt to cosntrol planktonic algal growth in Foxcote water supply reservoir, which is supplied by eutrophic waters from the river Great Ouse, ferric sulphate has been used to reduce ortho‐phosphate concentrations in the pumped inlet water. Internal recycling of sediment‐bound nutrients retarded the expected algal control for almost three years. During the third year, a marked change in the ecology of the reservoir occurred, and planktonic algae were largely replaced by prolific growths of filamentous species and rooted macrophytes. While the changed flora have caused their own problems, the reservoir is now less prone to closure due to intractable water treatment problems.