The Wadden Sea constitutes one of the world’s most important wetlands for migratory waterbirds. It is the single most important staging and moulting area and an important wintering area for waterbirds on the East Atlantic Flyway from the Arctic to South Africa. The Joint Monitoring of Migratory Birds (JMMB) program is carried out in the framework of the Trilateral Monitoring and Assessment Program (TMAP), and constitutes an internationally coordinated long-term monitoring program. It covers a large connected eco-region stretching from Den Helder in The Netherlands to Esbjerg in Denmark; regular ground counts for most species and areas plus aerial counts for seaducks involves hundreds of observers and several institutes and agencies.
After the publication of trends, comprehensive species accounts and assessments in the most recent reports (Blew et al. 2005 and Blew et al. 2007), the JMMB group agreed, that from now on a yearly update of these trend calculation shall be published on this website. Here, trends of 34 waterbird species for the international Wadden Sea and the four regions - The Netherlands, the Federal States of Germany, Niedersachsen and Schleswig-Holstein, and Denmark will be presented.

Details of the “Joint Monitoring program of Migratory Birds in the Wadden Sea” are given in Rösner et al., (1993) and updated in Blew et al., (2005). This program, consisting of international synchronous counts, spring-tide counts and aerial counts (only Common Eider), has been carried out by all Wadden Sea countries since 1992. Some differences between the countries’ programs exist, due to different national approaches and older already existing counting programs, but these do not hamper the overall goal for calculating trends. Because many usable counting data before 1992 exist as well, it has been decided to include counts back to the season 1987/1988.
The area considered is the Wadden Sea Cooperation Area. This is, in general terms, the area seaward of the main dike (or, where the main dike is absent, the spring-high-tide-water line, and in the rivers, the brackish-water limit) up to 3 nautical miles from the baseline or the offshore boundaries of the Conservation Area (Essink et al., 2005). The total area covers 14,700 km², with 4,534 km² of tidal flats.

Trends, methods, an overview map of the study area and references for the Trilateral Monitoring and Assessment Program for migratory birds can be found here: