The Wadden Sea is among the largest coastal wetlands in the world. It is a key area and the most important staging site along the East Atlantic Flyway for birds moving between breeding areas in the Arctic from Canada/Greenland in the west to Siberia in the east to wintering areas in West Europe, the Mediterranean and Africa. The Wadden Sea’s shallow, tidal influenced waters, its extensive tidal flats and adjacent saltmarshes provide food for about 12 million waterbirds which stop to build up their fat reserves for their further migration, moulting during autumn or staging during winter. At least 52 populations of 41 migratory waterbirds use the Wadden Sea annually. Of these, the numbers of 44 populations of 34 species are large enough for the Wadden Sea to be considered as their most important stopover site during migration (Meltofte et al., 1994, Blew et al., 2005a).