Editing Norwegian Sea (section)

=== Plankton and sea bottom organisms ===
Most of the aquatic life in the Norwegian Sea is concentrated in the upper layers. Estimates for the entire North Atlantic are that only 2% of biomass is produced at depths below 1,000 metres and only 1.2% occurs near the sea floor.<ref name="Schäfer81">Andrea Schröder-Ritzrau ''et al.'', ''[https://books.google.com/books?id=iVAzudOPt1kC&pg=PA81 Distribution, export and alteration of plankton in the Norwegian Sea Fossiliziable]''. [[#refSchaefer|Schaefer, 2001]], pp. 81–104</ref>

The blooming of the [[phytoplankton]] is dominated by [[chlorophyll]] and peaks around 20 May. The major phytoplankton forms are [[diatoms]], in particular the genus ''[[Thalassiosira]]'' and ''[[Chaetoceros]]''. After the spring bloom the [[haptophytes]] of the genus ''[[Phaecocystis pouchetti]]'' become dominant.<ref name="ICES5">[[#refICES|ICES, 2007]], pp. 5–8</ref>

<gallery class="center" widths="160px" heights="130px">
File:Hyperia.jpg|[[Hyperiidea]]
File:Pandborealisind.jpg|Shrimp ''[[Pandalus borealis]]''
File:Lophelia pertusa.jpg|''[[Lophelia pertusa]]''
File:Meganyctiphanes norvegica.jpg|''[[Northern krill|Meganyctiphanes norvegica]]''
</gallery>

Zooplankton is mostly represented by the [[copepods]] ''Calanus finmarchicus'' and ''Calanus hyperboreus'', where the former occurs about four times more often than the latter and is mostly found in the Atlantic streams, whereas ''C. hyperboreus'' dominates the Arctic waters;<ref name="ICES5"/> they are the main diet of most marine predators.<ref name="Skreslet103" /> The most important krill species are ''[[Northern krill|Meganyctiphanes norvegica]]'', ''[[Thyssanoessa inermis]]'', and ''[[Thyssanoessa longicaudata]]''.<ref name="ICES5"/> In contrast to the Greenland Sea, there is a significant presence of [[calcareous]] plankton ([[Coccolithophore]] and [[Globigerinida]]) in the Norwegian Sea.<ref name="Schäfer81"/> Plankton production strongly fluctuates between years. For example, ''C. finmarchicus'' yield was 28 g/m<sup>2</sup> (dry weight) in 1995 and only 8 g/m<sup>2</sup> in 1997; this correspondingly affected the population of all its predators.<ref name="ICES5"/>

Shrimp of the species ''[[Pandalus borealis]]'' play an important role in the diet of fish, particularly cod and [[blue whiting]], and mostly occur at depths between 200 and 300 metres. A special feature of the Norwegian Sea is extensive coral reefs of ''[[Lophelia pertusa]]'', which provide shelter to various fish species. Although these corals are widespread in many peripheral areas of the North Atlantic, they never reach such amounts and concentrations as at the Norwegian continental slopes. However, they are at risk due to increasing [[trawling]], which mechanically destroys the coral reefs.<ref name="ICES5"/>