Editing Bering Sea (section)

==Ecosystem==
The Bering Sea [[Continental shelf|shelf break]] is the dominant driver of [[primary production|primary productivity]] in the Bering Sea.<ref name="Springer">{{Cite journal | doi = 10.1111/j.1365-2419.1996.tb00118.x| title = The Bering Sea Green Belt: Shelf-edge processes and ecosystem production| journal = Fisheries Oceanography| volume = 5| issue = 3–4| pages = 205| year = 1996| last1 = Springer | first1 = A. M. | last2 = McRoy | first2 = C. P. | last3 = Flint | first3 = M. V. | bibcode = 1996FisOc...5..205S}}</ref> This zone, where the shallower [[continental shelf]] drops off into the [[North Aleutians Basin]] is also known as the "Greenbelt". Nutrient upwelling from the cold waters of the Aleutian basin flowing up the slope and mixing with shallower waters of the shelf provide for constant production of [[phytoplankton]].

The second driver of productivity in the Bering Sea is seasonal [[sea ice]] that, in part, triggers the spring phytoplankton bloom. Seasonal melting of sea ice causes an influx of lower salinity water into the middle and other shelf areas, causing stratification and hydrographic effects which influence productivity.<ref name="Schumacher">{{Cite journal | doi = 10.1175/1520-0485(1979)009<0079:ASFOTC>2.0.CO;2| title = A Structural Front over the Continental Shelf of the Eastern Bering Sea| journal = [[Journal of Physical Oceanography]]| volume = 9| issue = 1| pages = 79| year = 1979| last1 = Schumacher | first1 = J. D.| last2 = Kinder | first2 = T. H.| last3 = Pashinski | first3 = D. J.| last4 = Charnell | first4 = R. L.| bibcode = 1979JPO.....9...79S| doi-access = free}}</ref> In addition to the hydrographic and productivity influence of melting sea ice, the ice itself also provides an attachment substrate for the growth of algae as well as interstitial ice algae.<ref>{{Cite journal |last1=Olsen |first1=Lasse M. |last2=Duarte |first2=Pedro |last3=Peralta-Ferriz |first3=Cecilia |last4=Kauko |first4=Hanna M. |last5=Johansson |first5=Malin |last6=Peeken |first6=Ilka |last7=Różańska-Pluta |first7=Magdalena |last8=Tatarek |first8=Agnieszka |last9=Wiktor |first9=Jozef |last10=Fernández-Méndez |first10=Mar |last11=Wagner |first11=Penelope M. |last12=Pavlov |first12=Alexey K. |last13=Hop |first13=Haakon |last14=Assmy |first14=Philipp |date=2019-07-02 |title=A red tide in the pack ice of the Arctic Ocean |journal=[[Scientific Reports]] |volume=9 |issue=1 |pages=9536 |doi=10.1038/s41598-019-45935-0 |issn=2045-2322 |pmc=6606610 |pmid=31266996|bibcode=2019NatSR...9.9536O }}</ref>

Some evidence suggests that great changes to the Bering Sea ecosystem have already occurred. Warm water conditions in the summer of 1997 resulted in a massive bloom of low energy [[coccolithophore|coccolithophorid]] phytoplankton (Stockwell et al. 2001). A long record of [[Isotopic signature|carbon isotopes]], which is reflective of primary production trends of the Bering Sea, exists from historical samples of bowhead whale [[baleen]].<ref name="Schell">{{Cite journal | doi = 10.4319/lo.2000.45.2.0459| title = Declining carrying capacity in the Bering Sea: Isotopic evidence from whale baleen| journal = [[Limnology and Oceanography]]| volume = 45| issue = 2| pages = 459–462| year = 2000| last1 = Schell | first1 = D. M. | bibcode = 2000LimOc..45..459S| doi-access = free}}</ref> Trends in carbon isotope ratios in whale baleen samples suggest that a 30–40% decline in average seasonal primary productivity has occurred over the last 50 years.<ref name="Schell"/> The implication is that the [[carrying capacity]] of the Bering Sea is much lower now than it has been in the past.