Ecological aspects of the Zuiderzee Project

In this paper firstly history, objectives, management and decision making process of the Zuiderzee Project are described. Then the ecological situation as it existed before 1930 will be discussed, followed by a description of the changes resulting from enclosure the Zuiderzee. Afterwards development in waterquality and significancy for birds in IJsselmeer, Markermeer, Ijmeer and Border Lakes are regarded in relation to engineering, management and planning. Also the significance of the reclaimed polders for birds and some effects or urbanization upon ecological values are discussed. Much attention is given to birds, because they can be seen as indication for functioning of the system as a whole. Finally are described integration of results of ecological studies in planning and execution of successive stages of the Zuiderzee Project.