Internationally speaking the Wadden Sea of Schleswig-Holstein is subject to the Ramsar-Convention on Wetlands of International Importance. Since 2002 the area is also listed as a Particularly Sensitive Sea Area (PSSA). Additionally the national park is subject to a trilateral convention for protecting grey seals, harbour seals and Cetaceans called ‘Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas’ as well as to the Agreement on the Conservation of African-Eurasian migratory water birds. The area is designated for the purpose of the Bird directive of the European Union (79/409/EWG) as well as the for the purpose of the Habitats Directive and therefore a part of the European Natura 2000 nature protection network. As a part of the Marine Strategy Framework Directive the ecological status of the Wadden Sea has to be protected and improved. In the purpose of the Waterframework directive the national park is partly assigned to the Flussgebietseinheit (FGE) Eider, a so called "unit of the river basin Eider", and partly to the FGE Elbe. Harbour seals are protected in the Wadden Sea by the ‘Agreement on the Conservation of Seals in the Wadden Sea’. The 26 July 2009 the Wadden Sea of Schleswig-Holstein received the Status of UNESCO World Heritage together with the Wadden Sea of Lower Saxony and the Netherlands. The adjacent Wadden Sea of Hamburg received the Status in 2011, the National Park Vadehavet in Denmark in 2014.