Beaufort Sea large marine ecosystem

Source: NOAA

Brief Description

caption Location of the Beaufort Sea LME. (Source: NOAA)

The Beaufort Sea Large Marine Ecosystem (LME) is characterized by its Sub-Arctic climate. It is a high-latitude marine region situated off the coast of northern Alaska, in the United States, and of Canada. The LME is characterized by its extreme environment, and is driven by major seasonal and annual changes in Arctic climate conditions. It is covered with ice for most of the year. The Beaufort Gyral Stream forms a clockwise drift pattern. Other relevant ecological criteria are bathymetry and trophodynamics. An LME book chapter pertaining to this LME is Carleton Ray and Hayden, 1993, which describes marine biogeographic provinces of the Bering, Chukchi and Beaufort Seas.


During the winter there is limited light penetration because of ice cover. In the summer when the ice melts, productivity estimates are significantly higher. The coastal region supports a wide diversity of organisms, some of which are unique to this coast. The Beaufort coastal areas provide habitat for ducks, geese, swans, shorebirds and marine birds. Many species of birds and fish rely on river deltas, estuaries, spits, lagoons and islands in coastal waters for breeding, food, shelter, and for rearing their young. The Beaufort Sea LME is considered a Class III, low productivity (<150 grams of Carbon per square meters per year (gC/m2-yr)) ecosystem based on SeaWiFS annual global primary productivity estimates. An important question is how this productivity might change under an altered climatic regime. For data on selected invertebrates, fishes, birds and mammals, see Carleton Ray and Hayden, 1993.

Fish and Fisheries

caption (Source: NOAA)

NOAA statistics on Alaska in “Our Living Oceans” apply to all of Alaska, without a specific statistical breakdown for the US section of the Beaufort Sea LME. For statistics on the Beluga and other marine mammals in the Beaufort Sea, see NOAA, 1999, p. 231. The key subsistence marine species are likely to undergo shifts in range and abundance due to climate change. The University of British Columbia Fisheries Center has detailed fish catch statistics on this LME. Click on the thumbnail image for more information. Twenty-one species of fish are harvested commercially, including Arctic cisco (Coregonus autumnalis), broad whitefish (C. nasus), least cisco (C. sardinella), and Dolly Varden char (Salvelinus malma). Several species (including the Dolly Varden char) are anadromous and move seasonally between freshwater and underground springs in the winter, and salt water in the summer. These species have adapted to Arctic conditions through complex migration patterns, late maturity and low recruitment rates.

Pollution and Ecosystem Health

Monitoring strategies have generally excluded The Beaufort Sea LME off of Alaska (USA) because of logistical problems. An area of concern is the effect of changes in the Arctic climate on fish, marine mammals, and associated wildlife. Changes in water flow, the transport of nutrients through the Bering Strait, and the loss of ice habitat caused by global warming will have an effect on the living marine resources of this LME. Oil and gas exploration, extraction, and transport in this LME are also a critical factor. New drilling projects targeting oil and gas in the Alaskan Beaufort Sea require constant monitoring. Recommended impact assessments should include analyses of potential mortality in the event of spills, damage to food sources, production-related changes in marine mammal distribution, movement, and abundance, and additionally, how the native people might be affected by exposure to contaminants in whales and other marine mammals from the oil industry. Pollution and disturbance from vessel traffic on the proposed Northern Sea Route is a concern.


Economic activity is mostly concerned with the exploitation of natural resources (petroleum, natural gas, fish, and seals). Fish contributes to the economy and provides protein for the region’s native people. The Inupiat harvest fish and bowhead whales. The Inuvialuit harvest several species of marine mammals. Ringed seals were once important to the local cash economy but the market for seal pelts has disappeared. Whaling, however, continues to be a key subsistence activity. Oil has been discovered in Prudhoe Bay, but offshore oil production costs are higher in the Arctic than elsewhere. The Northstar Project targets oil in the Alaskan Beaufort Sea, but scientists recommend that it should consider native hunters and consumers of whales in the area. Whales and other marine mammals might be exposed to contaminants from the oil industry. The protection of the regional lifestyle is a major socioeconomic theme, as is the need to protect and preserve the Arctic wildlife, its environment, and biological productivity.


The Beaufort Sea LME is bordered by Alaska (USA), by the Yukon Territory, the Inuvik Region, and part of the Northwest Territories (Canada). There are transboundary issues needing to be addressed by both countries. Governance for fisheries in Alaska comes under the Alaska Department of Fish and Game. In Canada, self-government is being negotiated by two native groups, the Inuvialuit and Gwich'in, to ensure that they retain control over their inherent rights and preserve their cultural identity and values within a changing northern society. A Beaufort Sea Beluga Management Plan was developed in 1993 by the Fisheries Joint Management Committee. The goals of the plan were to maintain a thriving population of beluga whales and a sustainable harvest of beluga for the Inuvialuit people.


Articles and LME Volumes

  • Ray, G. Carleton and B.P. Hayden, 1993. Marine biogeographic provinces of the Bering, Chukchi, and Beaufort Seas. In: K. Sherman, L.M. Alexander and B.D Gold, Large Marine Ecosystems—Stress, Mitigation, and Sustainability. AAA Press, p. 175-184. ISBN: 087168506X.

Other References

  • Aagaard, K., 1984. The Beaufort Undercurrent. In: The Alaskan Beaufort Sea: Ecosystems and Environment, edited by P. Barnes and E. Reimnitz, pp. 47- 71, Academic Press, New York, 1984. ISBN: 0120790300.
  • Lister, C.R.B., 1987. Geothemal resources, in Scholl, D.W., Grantz, Arthur, and Vedder, J.G., eds., 1987, Geology and resource potential of the continental margin of western North America and adjacent ocean basins - Beaufort Sea to Baja California: Houston Texas, Circom-Pacific council for energy and mineral resources, Earth Science Series, v. 6, p. 739-751. ISBN: 0933687060.
  • NOAA, 1999. Our living oceans—report on the status of U.S. Living Marine Resources, 1999. 301 pages.
  • Padman, L., and T. M. Dillon, 1987. Vertical fluxes through the Beaufort sea thermohaline staircase. Journal of Geophysical Research, 92, 10,799-10,806.

Disclaimer: This article is taken wholly from, or contains information that was originally published by, the National Oceanic and Atmospheric Administration (NOAA). Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the National Oceanic and Atmospheric Administration (NOAA) should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.



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