Table 1 Distinguishing features of the Nordic seas

Baltic Sea

60 m

Strong salinity gradients

Small pelagic fish

Structural shifts

From nine surrounding countries

[99, 115, 45, 89]

North Sea

0–500 m

Thermally mixed water column, soft sediments, varied coasts of Kattegat and Skagerrak seas

Herring, sandeel, sprat and Norway pout

Depletion or reduction of larger predatory species and coastal seagrass habitats

Major rivers, south Atlantic currents, and Baltic Sea

[81, 163, 108, 90]

North-East Atlantic

Deep ocean basins, > 1000 m

Entirely oceanic and distant from land

Lack of data, but coral reefs may be habitat for unique species

Simple food webs. Primary productivity is low

Ocean currents bring contaminants and litter from maritime sources

[98, 147, 88] 

Norwegian Sea

Two deep basins (3–4000 m deep)

Transition zone driven by the Norwegian Atlantic Current

Increase in mackerel & decline in herring

Complex food web

From western North Atlantic, North Sea, Baltic Sea, Greenland Sea & Barents Sea

[85, 87]

Icelandic waters / Greenland Sea

Below and above 500 m

Coastal shelves influenced by oceanic inputs

Capelin. Immigration of mackerel & herring

Primary production ranges from very low to high

Converging currents, melting ice, local fishing activities

[91, 92]

Barents Sea / Arctic Ocean

230 m

Influx of Atlantic waters

Cod, haddock, capelin, polar cod

Simple with few fish species

Human activities i.e., cargo, tourism & aquaculture

[60, 97, 40, 47, 86]