The Barents Sea is a marginal sea of the Arctic Ocean, located off the northern coasts of Norway and Russia and divided between Norwegian and Russian territorial waters. Known among Russians in the Middle Ages as the Murman Sea ("Norse Sea"), the current name of the sea is after the historical Dutch navigator Willem Barentsz.
This is a rather shallow shelf sea, with an average depth of 230 metres (750 ft), and it is an important site for both fishing and hydrocarbon exploration. The Barents Sea is bordered by the Kola Peninsula to the south, the shelf edge towards the Norwegian Sea to the west, and the archipelagos of Svalbard to the northwest, Franz Josef Land to the northeast and Novaya Zemlya to the east. The islands of Novaya Zemlya, an extension of the northern end of the Ural Mountains, separate the Barents Sea from the Kara Sea.
Although part of the Arctic Ocean, the Barents Sea has been characterised as "turning into the Atlantic" or in process of being "Atlantified" because of its status as "the Arctic warming hot spot." Hydrologic changes due to global warming have led to a reduction in sea ice and in stratification of the water column, which could produce major changes in weather in Eurasia. One prediction is that as the Barents Sea's permanent ice-free area grows additional evaporation will increase winter snowfalls in much of continental Europe.
Due to the North Atlantic drift, the Barents Sea has a high biological production compared to other oceans of similar latitude. The spring bloom of phytoplankton can start quite early near the ice edge, because the fresh water from the melting ice makes up a stable water layer on top of the sea water. The phytoplankton bloom feeds zooplankton such as Calanus finmarchicus, Calanus glacialis, Calanus hyperboreus, Oithona spp., and krill. The zooplankton feeders include young cod, capelin, polar cod, whales, and little auk. The capelin is a key food for top predators such as the north-east Arctic cod, harp seals, and seabirds such as common guillemot and Brunnich's guillemot. The fisheries of the Barents Sea, in particular the cod fisheries, are of great importance for both Norway and Russia.
SIZEX-89 was an international winter experiment in 1989 for which the main objectives were to perform sensor signature studies of different ice types in order to develop SAR algorithms for ice variables, such as ice types, ice concentrations and ice kinematics.Although previous research suggested that predation by whales may be the cause of depleting fish stocks, more recent research suggests that marine mammal consumption has only a trivial influence on fisheries. A model assessing the effects of fisheries and climate was far more accurate at describing trends in fish abundance. There is a genetically distinct polar bear population associated with the Barents Sea.