The Barents Sea is a heterogeneous system changing from boreal conditions in south-west to Arctic conditions in the north. To better reflect the changing conditions and trends over the large shelf and slope regions of the Barents Sea Large Marine Ecosystem (LME), we have subdivided the Barents Sea into twelve subareas shown in Figure 2.1.1 This division is a modified version of the system of subareas used in the analysis of spatial and temporal patterns of biomass of the pelagic compartment by Eriksen et al. (2017).
The Barents Sea opening with inflow of Atlantic water is divided into two subareas. The South-West subarea includes the system of banks along the north coast of Norway (Tromsøflaket and North Cape Bank) and the Norwegian Coastal Current. The Bear Island Trench is the deep area leading into the Barents Sea where most of the inflow of Atlantic water takes place. The Atlantic Current splits into two branches, one flowing east across the Thor Iversen Bank subarea located south of the Central Bank. This subarea consists of relatively deep banks that represents a shallowing between the deep areas of the Bear Island Trough and the South-East Basin. The Hopen Deep subarea is where the other branch of Atlantic water flows north. This is a deep area located between the shallower Central Bank in east and the Svalbard Bank in west.
The Central Bank subarea contains the Central Bank and the deeper areas between the Central Bank and Great Bank where Atlantic water from the Hopen Deep branch flows east on the way to the opening in northeast. The Central Bank has a clockwise circulation of water over it, and used to have Arctic conditions associated with ice freezing and formation of cold bottom water in winter. With warming this is now changing. The Great Bank subarea (or the Persey Elevation) to the north is another major bank in the northern Barents Sea which is traditionally an important summer feeding area for the Barents Sea capelin stock. The Svalbard subarea is heterogeneous with the Svalbard (or Spitsbergen) Bank and the Storfjord-system south of the archipelago along with the West Spitsbergen and North Svalbard shelf and slope areas. The Franz-Victoria Trough subarea lies between Svalbard and Franz Josef Land and includes the Franz-Victoria Trough leading into Olga Deep south of Kong Karls Land as well as the shelf region around Kvitøya and Victoria Island. The Franz Josef Land subarea is the waters around the archipelago bounded by St. Anna Trough in the Kara Sea in east and a line along approximately 78.5°N in south.
The Northeast subarea is the area east of the Great Bank and Central Bank and includes the Northeastern Basin, Novaya Zemlya Bank, the sill region between Novaya Zemlya and Franz Josef Land, and the head of the St. Anna Trough leading into the northern Kara Sea. The South-East Basin includes the deep basin and the surrounding slopes to the east of the Central Bank and Thor Iversen Bank. The South-East subarea is comprised of the general shallow waters of the southeastern Barents Sea with the Murmansk Rise, North Kanin Bank, and Goose Bank, and the Pechora Sea.