Together with the Danish and German sections, the Wadden Sea (Waddenzee) is the largest intertidal area in Europe. Important habitats of the ecosystem include mudflats, sandflats, saltmarshes, shallowly submerged sandbanks, and estuaries. The Dutch section is bounded by the Waddeneilanden and the mainland. It was separated from Lake IJsselmeer (site 034) in 1932 and from the Lauwerszee (015) in 1969. The Wadden Sea IBA includes the main part of the intertidal system but the main isles (005, 009), the bays (013, 017) and the saltmarshes/forelands (002-004, 006-008, 010-014, 016) have been considered as separate sites. The area covered by the Wadden Sea Memorandum (national policy paper), of which the boundary is determined by the mean of the annual maximum high-water mark, overlaps with these sites and has a total area of 272,100 ha. Human activities include extraction of natural gas and of sand, and shellfish fisheries.
The Wadden Sea is a major breeding, staging, wintering, feeding and moulting area for huge numbers of many duck, goose, wader, gull and tern species. No numbers are given for breeding birds as most nest in immediately adjacent IBAs. This complex site was not taken into account for the application of C6 criterion (`five most important sites in NUTS region'), because of its close proximity to adjacent sites (002-014, 016-017).
Pressure/threats to key biodiversity
Mechanical fishing of cockles Cardium by suction dredging, military training, recreation, and gas extraction are the main threats to the area. Cockle fishing affects the food resources of birds such as Somateria mollissima and Haematopus ostralegus and destroys the sediment structure, while all long-established banks of mussels Mytilus have been removed, and the recovery of eel-grass Zostera is hindered. The Special Protection Area and the Ramsar designation cover the whole of this site although the area-sizes given in the designation orders are much less. The two Natural Monuments together cover about 85% of the area, including all of the saltmarshes and most of the intertidal flats. The current management plan covers the period 1996-2001.
National Partial International HighAbout 108,000 ha of IBA covered by Natural Monument (Waddenzee I, 125,000 ha). 79,700 ha of IBA covered by Natural Monument (Waddenzee II, 80,000 ha). 233,855 ha of IBA covered by Special Protection Area (Waddenzee, `250,000 ha' [official, incorrect figure]). 233,855 ha of IBA covered by Ramsar Site (Waddenzee, `250,000 ha' [official, incorrect figure]). 233,855 ha of IBA covered by Biosphere Reserve (Waddenzee, 260,000 ha).
BirdLife International (2020) Important Bird Areas factsheet: Wadden Sea. Downloaded from
http://www.birdlife.org on 27/11/2020.