Editing Norwegian Sea (section)

=== Fish ===
[[File:Clupea harengus.png|thumb|Atlantic herring]]

The Norwegian coastal waters are the most important spawning ground of the [[Atlantic Herring|herring populations]] of the North Atlantic, and the hatching occurs in March. The eggs float to the surface and are washed off the coast by the northward current. Whereas a small herring population remains in the fjords and along the northern Norwegian coast, the majority spends the summer in the Barents Sea, where it feeds on the rich plankton. Upon reaching puberty, herring returns to the Norwegian Sea.<ref name="Blindheim382">[[#refBlindheim|Blindheim, 1989]], pp. 382–401</ref> The herring stock varies greatly between years. It increased in the 1920s owing to the milder climate and then collapsed in the following decades until 1970; the decrease was, however, at least partly caused by overfishing.<ref name="Wefer"/> The biomass of young hatched herring declined from 11 million tonnes in 1956 to almost zero in 1970;<ref name="Skreslet103"/> that affected the ecosystem not only of the Norwegian Sea but also of the Barents Sea.<ref name="Stokke">Olav Schram Stokke ''Governing High Seas Fisheries: The Interplay of Global and Regional regime,'' Oxford University Press, 2001 {{ISBN|0-19-829949-4}}, pp. 241–255</ref>

[[File:Mallotus villosus.gif|thumb|[[Capelin]] is a common fish of the Atlantic-arctic transitional waters]]
Enforcement of environmental and fishing regulations has resulted in partial recovery of the herring populations since 1987.<ref name="Wefer"/><ref name="Skreslet103"/> This recovery was accompanied by a decline of capelin and cod stocks. While the capelin benefited from the reduced fishing, the temperature rise in the 1980s and competition for food with the herring resulted in a near disappearance of young capelin from the Norwegian Sea.<ref name="Helfman321">Gene S. Helfman ''Fish Conservation: A Guide to Understanding and Restoring Global Aquatic Biodiversity and Fishery Resources'', Iceland Press, 2007 {{ISBN|1-55963-595-9}}, pp. 321–323</ref> Meanwhile, the elderly capelin population was quickly fished out. This also reduced the population of cod – a major predator of capelin – as the herring was still too small in numbers to replace the capelin in the cod's diet.<ref name="Helfman321"/><ref name="NRC">National Research Council (U.S.). Committee on Ecosystem Management for Sustainable Marine Fisheries: Sustaining Marine Fisheries, National Academies Press, 1999, {{ISBN|0-309-05526-1}}, p. 46</ref>

[[File:Micromesistius poutassou Gervais.jpg|thumb|Blue whiting]]

[[Blue whiting]] (''Micromesistius poutassou'') has benefited from the decline of the herring and capelin stocks as it assumed the role of major predator of plankton. The blue whiting spawns near the British Isles. The sea currents carry their eggs to the Norwegian Sea, and the adults also swim there to benefit from the food supply. The young spend the summer and the winter until February in Norwegian coastal waters and then return to the warmer waters west of Scotland.<ref name=b366/> The Norwegian Arctic cod mostly occurs in the Barents Sea and at the [[Svalbard]] Archipelago. In the rest of the Norwegian Sea, it is found only during the reproduction season, at the Lofoten Islands,<ref name="Blindheim382"/> whereas ''[[Pollachius virens]]'' and [[haddock]] spawn in the coastal waters.<ref name=b366/> [[Mackerel]] is an important commercial fish. The coral reefs are populated by different species of the genus ''[[Sebastes]]''.<ref name="ICES5"/>