Wadden Sea and Dutch Delta

The Wadden Sea is an international, highly productive estuarine area, and one of the largest coastal wetlands in the world. Situated abreast mainland Europe in the south-eastern portion of the North Sea, it borders Germany, the northern portion of the Netherlands, and western Denmark, thereby requiring tri-lateral cooperation in the management and protection of the system. This coastal area is a biodiversity hotspot due to its positioning as a convergence point of multiple domains, including terrestrial, fresh water, brackish and marine habitats. This multi-faceted combination allows for the support of a wide breadth of biota.

The Wadden Sea is characterized by extensive tidal mud flats, saltmarshes, and deeper tidal creeks between the mainland and chain of islands which denote the outer boundary between the Wadden and North Sea. This mosaic of systems interacts dynamically due to wind, wave, tidal and riverine/runoff forcing functions, resulting in the creation of different types of coastlines. The common composition of such a coastline includes one or all of the following : i) a barrier coast with lido, barrier islands, mudflat systems and coastal lagoons, ii) deltaic systems and iii) bar-built and funnel-shaped estuaries. In the case of the Wadden Sea, all aspects are included to varying degrees.

The area has both UNESCO World Heritage and Natura 2000 status. It is approximately 500 km long with a surface area of around 9000 km2, a quarter of which is located within the Netherlands. Almost the entire region is submerged at high tide, and half the area (the mud flats where many birds feed) is exposed during low tide. As with many lagoonal and estuarine systems, the variety of habitats and high productivity lends itself to having a large biodiversity of invertebrates, fish, birds and marine mammals.

The high value ascribed to the Wadden Sea comes from its important regulatory and maintenance functions for the south-eastern coastal portion of the North Sea, its diverse aesthetic values, and the protection it offers against westerly storms to the German, northern Dutch, and western Danish coasts. The Wadden Sea is a nursery area for many fish species as well as a resting and fuelling station for a wide variety of wading birds. More than half of the juvenile plaice, a flatfish, population of the North Sea grow up in the area. Moreover, more than 10 million birds spend varying degrees of time in the region, often on migratory routes between nesting grounds near the North Pole to wintering sites as far south as Africa. This treasured combination of varied species and aesthetics draws a high volume of tourists in many forms, including but not limited to island visitors, game fisherman, boating and mudflat walking excursionists, and commercial operations. Commercial activities include industrial fishing for commercial fish and shellfish; recently aquaculture for shellfish has been introduced. One of the objectives of the application of protected area status to the Wadden Sea is to limit the degree of exploitation by the commercial shellfish industry whose high degree of pressure through mussel extraction has significantly impacted the system’s capacity to support the large volume of migratory birds.

The management goals of the Wadden Sea are primarily at the national level, but agreements have been made between all three countries which have stake in a portion of the systems to have the policy and management developed at the trilateral level; see http://www.waddensea-secretariat.org/trilateral-cooperation/organisational-structure. Note that this organizational body needs to be taken into account when addressing future management issues of the Wadden Sea.


Wadden Sea - Table of ecosystem services/functions and available data


Dutch Delta - Table of ecosystem services/functions and available data




Click here to download a poster of the protected area.