chapter  16
34 Pages

1Chapter 6 The Wadden Sea: A Coastal Ecosystem under Continuous Change

The Wadden Sea is one of the largest coastal lagoons in the world, characterized by extensive wetlands, high biotic production, and valuable recreational and commercial fisheries. Based on physicochemical and biotic conditions, the Wadden Sea can be divided into three main regions: (1) the southern Wadden Sea (tidal range = 1.5 to 3 m) bounded by 12 elongated islands forming a sandy barrier 5 to 15 km parallel to the mainland; (2) the central Wadden Sea (tidal range >3 m) lacking barrier islands and ebb-deltas due to macrotidal conditions and the large volume of tidal water exchange; and (3) the northern Wadden Sea (with a tidal range decreasing from 3 to 1.2 m in a northward direction) consisting of 8 islands and high sand bars that form a seaward barrier some 5 to 25 km off the mainland coastline. Each region can be further divided into subareas, some of which are strongly influenced by freshwater inputs from large rivers such as the Rhine, IJssel, Ems, Weser, and Elbe, while others are considered to be dominated by coastal North Sea water. The Wadden Sea has a long history of human impacts. During the twentieth century, the exploitation

Abstract .......................................................................................................................................... 399 16.1 Introduction ..........................................................................................................................400 16.2 Physiography .........................................................................................................................400 16.3 Major Changes ......................................................................................................................403