Transformation of a Delta : converting estuaries to lakes

Large-scale transformations have been carried out in the delta of the Rhine, Meuse and Scheldt in the loss of estuarine ecosystems, the change in the process of sedimentation and erosion, and the development of new aquatic and terrestial ecosystems. The ecological consequences of the transformation of the Grevelingen estuary into a salt-water lake and some surprising developments are described briefly. The need for a limited restoration of the water exchange between the lake and the North Sea is indicated, as well as the major impacts of the exchange. The necessity for the maintenance or restoration of estuaries, the ecological development and the possibilities of the new lakes, and the management, backed by research, are needed to make the fullest possible use of the potential offered by new lakes. It is also concluded that salt lakes have interesting perspectives.