The Site is a marine and coastal wetland in the Wadden Sea, between the mainland and barrier islands, consisting of extensive tidal mudflats, salt marshes, wet meadows, reclaimed polders, sand banks, and dune systems. The Ramsar Site boundary has been adjusted to follow the Natura 2000 boundary, and the former Ramsar Sites Griend (former Site no. 196) and Boschplaat (former Site no. 195) as well as 750 ha of the nature development area Friesland Buitendijks have been included within the Wadden Sea Ramsar Site. These changes have together resulted in an area increase of over 5,000 ha. Waddenzee is internationally important for many threatened species such as avocet and Sandwich tern, as well as for more than 20,000 wintering migratory birds. In addition, more than 5,000 individuals of harbour seal regularly use the site. The coastal wetland plays an important role in flood regulation, shoreline stabilization and sediment trapping. The main activities within the Site are commercial fisheries, sand, clay, shell and gravel extraction, oil and gas exploitation, wind turbine electricity generation and military training. All these activities are potential threats to its ecological character. The management plan was updated in 2010.