It is a temperate semi-enclosed coastal shelf sea connected to the Norwegian Sea and Celtic Seas ecoregion in the north, the Bay of Biscay and Iberian Coast ecoregion in the south and the Baltic Sea ecoregion in the east. Its oceanography is characterized by a permanently thermally mixed water column in the south and east and seasonal stratification in the north as well as exchanges with the adjacent Atlantic and Baltic waters.
The ecoregion consists of four key areas:
- The northern North Sea (depths 0–500 m), strongly influenced by Atlantic oceanic inflow and has the deep Norwegian trench in the east. The majority of the area is stratified in summer. The dominant human activities are fishing and oil and gas production.
- The southern North Sea (depths 0–50 m), characterized by large river inputs, tidal currents, and shallow waters, which result in a strongly mixed water column all year round. The dominant human activities are fishing, shipping, ports, gas production, wind farms, and aggregate (sand) extraction.
- The Skagerrak and Kattegat form the link to the Baltic Sea and are less saline and less tidal than the rest of the ecoregion. The water column is predominatly stratified. The dominant human activities are fishing, shipping, and wind farms.
- The English Channel joins the southern North Sea to the Atlantic. It is usually mixed and strongly influenced by wind and tidal events. The dominant human activities are fishing, shipping, and aggregate (gravel) extraction.
Management
The Greater North Sea ecoregion includes all or parts of the Exclusive Economic Zones (EEZ) of six EU Member States (MS; France, Belgium, the Netherlands, Germany, Denmark, and Sweden), as well as Norway and United Kingdom (UK). The ecoregion strongly overlaps with the North Sea Advisory Council (NSAC) administrative region, OSPAR Region II and large marine ecosystem (LME) 22.
The key policies for conservation in the EU are: the Birds and Habitats Directives (including the Natura 2000 ecological network), the Marine Strategy Framework Directive (MSFD), and the Biodiversity Strategy 2030. Norway and UK have similar national regulations, such as the Norwegian Integrated Management of the Marine Environment of the North Sea and Skagerrak or the UK Marine Strategy. Marine mammal issues are considered in cooperation under the North Atlantic Marine Mammal Commission (NAMMCO).
Key policies that regulate human activities in the EU are: the Integrated Maritime Policy, the Maritime Spatial Planning Directive (MSP), and the Blue Growth Strategy. International shipping is managed under the International Maritime Organization (IMO; through, for example, the International Convention for the Prevention of Pollution from Ships [MARPOL], the International Convention on the Control of Harmful Anti-fouling Systems on Ships [AFS], and the International Convention for the Control and Management of Ships' Ballast Water and Sediments). Oil and gas related activities are managed at national level (in accordance with the OSPAR Convention and the Bonn Agrement).
Fisheries management in the ecoregion are partly affected through coastal state agreements between the EU, Norway, and UK, which covers most commercial demersal fish, small pelagic fish, and Norway lobster (Nephrops norvegicus) fisheries. The majority of shellfish fisheries (i.e. all except Norway lobster) are determined as national responsibilities. Managerial responsibility for salmon is taken under the North Atlantic Salmon Conservation Organization (NASCO) and for large pelagic fish by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Fisheries policy is determined by national governments (UK and Norway) and the EU Common Fisheries Policy. Collective fisheries advice is provided by the International Council for the Exploration of the Sea (ICES), the European Commission's Scientific Technical and Economic Committee for Fisheries (STECF), and the North Sea (NSAC), and the Pelagic Advisory Councils. Environmental policy is managed by national governments and agencies and OSPAR, with advice being provided by national agencies, OSPAR, the European Environment Agency (EEA), and ICES.
