Barents Sea Ecosystem

• Category: Marine and Oceanic Biomes.
• Geographic Location: North of Norway and Russia.
• Summary: The Barents Sea hosts large flocks of seabirds and stocks of fish. Although on the fringe of civilization, it is exposed to overfishing, oil exploration, and nuclear contamination.

A branch of the Arctic Ocean, the Barents Sea ecoregion includes the heavily glaciated arctic archipelagos of Svalbard and Franz Josef Land to the north, and Novaya Zemlya to the east. It extends to mainland Norway and Russia, and abuts the coastal White Sea along northwestern Russia. Bordered to the west by the Greenland Sea and to the southwest by the Norwegian Sea, the Barents Sea receives flow from warm currents through the latter; this North Atlantic Drift current helps keep ports along its southern shores ice-free in winter. The Barents is considered the warmest of the circumpolar seas—although its northern reaches are ice-bound most of the year, and it receives cold polar currents from several directions.

A continental-shelf sea, the Barents has an average depth of 755 feet (230 meters). With a surface area of 540,000 square miles (1.4 million square kilometers), water volume is about 77,250 cubic miles (322,000 cubic kilometers).

Indigenous settlements of the Same people (formerly called Lapps) within the biome are widespread across the northernmost European coastal areas. There is also a sparse presence of the Nenets and the Komi along the Russian northern rim. Traditionally, the peoples have been fishermen, hunters, and reindeer herders. Present-day economic activities extend to mining and some agriculture. Contemporary human pressures affecting the Barents come largely from the major shipping, fishery, and petroleum development activities in Norwegian and Russian territorial waters.

Species Richness

The benthic (deep sea layer) fauna and flora of the Barents Sea is diverse, including approximately 2,500 vertebrate species and up to 300 species of phytoplankton. The mixing of warmer North Atlantic Drift waters with cold Arctic Sea waters, as well as nutrient-rich river inflows from the continent, together provide a fertile basis for vast amounts of krill, copepods, jellyfish, and mollusks. In addition, there are extensive cold water reefs that harbor crustacean populations and anchor kelp forests, making for even greater biological productivity.

Capelin (Mallotus villosus) in great numbers feed upon crustaceans and krill here, forming a vast feast for higher creatures including the economically vital cod, cetaceans, and other marine mammals and seabirds. Besides the cod (Gadus morhua) and polar cod, the Atlantic salmon (Salmo salar) is a major component of the fisheries. Th ecosystem boasts over 150 different species of fish in its waters.

The large stocks of fish and plankton in the Barents Sea support some 20 million seabirds during summer months. Out of the thirty key seabird species in the biome, the little auk (Alle alle), black-legged kittiwake (Rissa tridactyla), common guillemot (Uria aalge), and Atlantic puffin (Fratercula arctica) make up more than half of the breeding population.

Marine Mammals

The Barents Sea ecoregion host twenty-four species of marine mammals: twelve species of large cetaceans, five of dolphins, and seven pinnipeds. Most of the dolphins and cetaceans are long-distance migrants; the only three permanent residents are the narwhal (Monodon monoceros), white whale or beluga (Delphinapterus leucas), and bowhead whale (Balaena mysticetus). Among the whales, the northern right whale (Eubalaena glacialis) came to the brink of extinction due to industrial whaling pressure, while the blue whale (Balaenoptera musculus) and bowhead whale have not recovered their population size since the major whaling period. The fate of the other cetaceans is at risk; among those listed as endangered, vulnerable, or rare in Russia and/or Norway are the sei (Balaenoptera borealis), fin whale (Balaenoptera physalus), and narwhal.

The polar bear (Ursus maritimus) was also close to extinction as a result of hunting but in 1973 was protected and its population is recovering; estimated numbers range from 3,000 to 5,000 individuals. Among the pinnipeds, the walrus (Odobenus rosmarus) was close to extinction by the 1950s and is currently listed as protected in Norway and vulnerable in Russia. In contrast, the population of the harp seal (Pagophilus groenlandicus) is about 1.2 million; it is a dominant species here, spending winters on the ice and the rest of the year in open water.

Economy and Threats

The rich biodiversity of the Barents Sea ecoregion faces great challenges. Among them are the fishing industry, radioactive contamination, shipping activities, petroleum exploration and exploitation, introduced species, deep sea mining, and climate change in the near future. Large-scale offshore fisheries came in by the middle of the twentieth century, building upon centuries of more artisanal fishing techniques. Among the most devastating industrial techniques are bottom trawling, dredging, and the use of drift nets. The first two damage the ocean bottom and deepwater corals, while drift nets are responsible for drowning adult seabirds. In spite of the large fish stocks in the region, the population of fish diminished greatly; for instance, spring-spawning Norwegian herring (Clupea harrengus) stocks crashed in the 1960s and took more than twenty years of concerted efforts to rebuild.

The Barents Sea and its sediments have been impacted by the introduction of manufactured nuclear material from a variety of sources. These include atmospheric fallout, including from the Chornobyl disaster; radioactive industrial material discharged by European nations and dumped at sea by the former Soviet Union; and nuclear reactor and weapons testing by the Soviet Union in Novaya Zemlya. Heavy metals like mercury and lead, as well as persistent organic pollutants (POPs) like DDT (dichlorodiphenyltrichloroethane), HCHs (hexachlorocyclohexanes), and PCBs (polychlorinated biphenyls), also find their way to the Barents Sea. Since POPs are fat soluble, they readily bioaccumulate as they move up the food chain toward top predators.

Since 1980, the Barents Sea has seen continually accelerating gas and oil exploration. Potential undersea fields are being actively developed in both the Norwegian and Russian zones. Underwater construction, spills, and increased shipping traffic are ongoing risks. Interest in deep sea mining and Norway's openness to allowing such activities in the Barents Sea raises concerns among environmentalists. Researchers warn of the threat such activities pose to biodiversity in the region. Further, with global warming, it is predicted that the opening of sea lanes across the deicing polar waters north of Europe and Asia will see industrial transport multiply at exponential rates, along with port facility and energy industry development.

On the aquaculture front, economically suitable fish such as various species of salmon and cod, as well as king crab (Lithodes maja, Paralithodes camtschaticus, et al.) are likely to make inroads into existing habitats, competing for food, as well as raising the risk of diluting the genetic defenses of their wild cousins through interbreeding. Introduced species reported in the Barents Sea already include a range of crab species as well as Pacific salmon and several plant types.

Conservation efforts have been made to protect parts of the Barents Sea ecoregion. The total marine protected area is 22,800 square miles (59,000 square kilometers), equal to less than 3 percent of the marine realm, while the protected land area (mostly islands) is 21,000 square miles (54,500 square kilometers).

One obstacle to continued rich biodiversity here is the prevalence of petroleum fields in highly sensitive habitats. The Norwegian Pollution Control Authority, for example, has called for the Nordland VI oil field to be declared a “petroleum-free area” due to its congruence with vital fish and seabird habitats.

Bibliography

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Hamre, Johannes. "Biodiversity and Exploitation of the Main Fish Stocks in the Norwegian-Barents Sea Ecosystem." Biodiversity and Conservation, vol. 3, no. 6, 1994, pp. 473-92.

Honneland, Geir. Making Fishery Agreements Work: Post-Agreement Bargaining in the Barents Sea. Edward Elgar, 2012.

Larsen, Tore, et al., editors. "Description of the Barents Sea Ecoregion." The Barents Sea Ecoregion: A Biodiversity Assessment. World Wildlife Fund, 2004, pp. 12-34.

Matishov, Dmitry G., and Gennady G. Matishov. Radioecology in Northern European Seas. Springer, 2010.

Sando, Anne Britt. "Only Modest Changes in Near Future Biological Production in the Barents Sea." Bjerkness Centre for Climate Research, 15 Dec. 2021, bjerknes.uib.no/en/article/news/only-modest-changes-near-future-biological-production-barents-sea. Accessed 29 Oct. 2024.