14/18: LME FACTSHEET SERIES BEAUFORT SEA LME tic LMEs Arc BEAUFORT SEA LME MAP 18 of Map Canada LME Amundsen Gulf Victoria Island Iceland Inuvik Region Central Arctic Ocean Baffin Island 14 "1 ARCTIC LMEs Large Marine Ecosystems (LMEs) are regions of ocean space ! PAME developed a working map delineaMng 17 ArcMc Large of 200,000 km² or greater, that encompass coastal areas Marine Ecosystems (ArcMc LME's) in the marine waters of the from river basins and estuaries to the outer margins of a ArcMc and adjacent seas in 2006. In a consultaMve process conMnental shelf or the seaward extent of a predominant including agencies of ArcMc Council member states and other coastal current. LMEs are defined by ecological criteria, ArcMc Council working groups, the ArcMc LME map was including bathymetry, hydrography, producvity, and revised during 2012. The revised boundaries of the 18 tropically linked populaMons. The LME concept for current LMEs were mapped by the Ecosystem Approach ecosystem-based management has 5-module approach Expert Group (EA-EG) in a report of the consultaMve process. focused on producMvity, fish and fisheries, polluMon and This is the working map of ArcMc LMEs and used for ecosystem health, socioeconomics, and governance. descripMve purposes in the work of the ArcMc Council. This factsheet is one of 18 in a series of the Arc;c LMEs. OVERVIEW: BEAUFORT SEA LME The Beaufort Sea LME consists of two main parts: the shallow shelves around the margins in the south and east adjacent to a deep basin with depths greater than 3 km. The shelves are separated from the deep Beaufort Sea basin by steep slopes which consBtute a third main Victoria Island topographic feature. The deepest parts are around Cape Bathurst 3.500m deep. Prominent Polynya Amundsen features are the Mackenzie Gulf delta river and estuary and the Cape Bathurst Polynya in the Amundsen Gulf. Map: The Beaufort Sea LME. Source: AMSAIIC Report Mackenzie River Mouth The Mackenzie River is the most sediment-rich river in the Arcc and transports annually about 130 million tons of sediments into the Beaufort Sea. The Mackenzie and Amundsen Gulf region provides important breeding, feeding and migraBon habitats for birds, as Ice begins to form in early to mid-October, iniBally in do areas in the CoronaBon and Queen Maud gulfs the nearshore zones and extends outward to expand south of Victoria Island. Three subpopulaons of and eventually establish the landfast ice zone, usually polar bears inhabit this LME: the southern and by November, generally extending out to 20m depth northern Beaufort and M’Clintock subpopulaBons. growing to a 2m thick level. A mobile ice pack occupies the bulk of the Beaufort Sea region in The primary producon is relaBvely high due to winter. influence of nutrient-rich Pacific water, and zooplankton residing in the deeper offshore areas. As elsewhere in the Arcc, lack of light and nutrients There is probably a large migratory populaBon of are the two main factors limiBng phytoplankton polar cod in the eastern Beaufort Sea, which is a growth in the Beaufort Sea. Phytoplankton are, along major summer feeding area for large numbers of with zooplankton, the base of marine food webs in bowheads and belugas from migratory populaBons the Beaufort LME, as most other marine ecosystems. wintering in the Bering Sea. "2 ! MARINE MAMMALS Five species of marine mammals occur regularly in During summer, ringed seals are dispersed the Beaufort Sea: the bowhead whale, beluga whale, throughout open-water areas. Seasonal ringed seal, bearded seal, and polar bear. concentraMons of seals (related to food sources) are known in offshore waters of the Amundsen Gulf Bowhead and beluga whales region off the Tuktoyaktuk Peninsula and off Cape The recurrent polynya and ice-edge habitat make the Dalhousie in summer. In the Canadian Beaufort Sea, Cape Bathurst Polynya an important beluga, the bearded seal is most abundant over depths 25– bowhead whale, polar bear, and ringed seal feeding 50 m. During the summer open-water period, much ground. Beluga (around 40.000 individuals) and of the Canadian Beaufort is unsuitable for feeding bowhead whales (about 10.000 individuals) of the because the pack-ice habitat preferred by bearded large migratory Beaufort Sea and Bering-Chukchi- seals typically retreats north to waters deeper than Beaufort Sea populaMons, respecMvely, use the those used by bearded seals. In most areas, numbers polynya area in the eastern Beaufort Sea as their are low, but bearded seals are relaMvely common in main feeding ground in the early part of summer certain nearshore areas along southern Banks Island, (May–June). Cape Parry, and Herschel Island. The abundance of bearded seals is relaMvely low (1200-3100 in the The Bering-Chukchi-Beaufort Sea stock of bowhead eastern Beaufort Sea). whales winters in the Bering Sea, and most of the stock summers in the Canadian Beaufort Sea and Polar bear Amundsen Gulf. The spring migraMon across the Two subpopulaMons of polar bears occur in the BS western Beaufort Sea occurs through offshore ice LME: the Northern Beaufort Sea (1000 individuals) leads, generally from mid April to mid June, and Southern Beaufort Sea (1500) subpopulaMons. depending on ice condiMons. Most remain in During winter and spring, most polar bears are found offshore waters (>200 m deep) among the offshore on the sea ice, tending to concentrate along pressure pack ice in the central and eastern Beaufort Sea unMl ice that parallels the coasts, and in the vicinity of floe late July to mid August, when they begin to move edges. gradually toward coastal and nearshore areas. In summer, when the pack ice retreats offshore, polar Generally, adults move into Amundsen Gulf into bears are found along the edge of the pack ice. water depths 50–200 m off Bathurst Peninsula, small During years with lifle or no pack ice near the coast, (<10 m) sub adults move into coastal and nearshore polar bears are ogen found along the coastline and waters at water depths 10–50 m along the Yukon on barrier islands. In late March and early April, coast, and large sub adults move into nearshore and females that have denned on land return with their shelf waters at water depths 20–200 m off the Yukon cubs to the sea ice to hunt seals. In early summer, coast, Mackenzie Delta, and Tuktoyaktuk Peninsula. they are relavely concentrated in areas with irregular coastlines such as bays, parMcularly those Ringed and bearded seals within which ice remains longer than in other areas. During the spring breeding and molMng seasons, ringed seals are dispersed at low densiMes in the ice Polar bears of the Southern Beaufort populaMon throughout the southeastern Beaufort Sea. Prime move north with the retreaMng pack ice in summer breeding habitat are in areas with a high proporMon and move south in the autumn as ice develops to of ice cover and moderate water depths of 50–75 m. areas where they can hunt ringed and also bearded Ringed seal pups are born in April, mostly on landfast seals. Bears of the northern populaMon move north ice. with the retreaMng ice off western Banks Island and M’Clure Strait in summer and south and east into Amundsen Gulf when ice develops in fall. "3 ! BIRDS Sea-associated birds are widespread in substanMal in the estuaries of the Mackenzie, Anderson, numbers in coastal, nearshore, and offshore waters Colville, Sagavanirktok, and Canning rivers, and of the Beaufort Sea LME. The greatest numbers of numerous other smaller rivers and streams, support marine birds, at least several million, occur in large numbers of nesMng, brood-rearing, molMng, coastal and nearshore zones. The most numerous and feeding waterfowl and shorebirds during the among the marine birds are ducks and geese summer season. including eiders and other sea ducks, and various species of shorebirds. Important nesMng and molMng habitats for geese (greater white-fronted goose, Richardson’s cackling Seabirds, waterfowl (ducks, geese and swans), and goose, lesser Canada goose, snow goose) are found shorebirds (plovers, snipes, sandpipers, phalaropes on Kendall and Richards islands in the outer and others) use coastal and marine habitats to Mackenzie Delta, on bays along the Tuktoyaktuk larger or lesser degree during the annual cycle and Peninsula (Kukjutkuk Bay, Hutchinson Bay, McKinley are collecMvely called marine birds. Marine birds are Bay-Phillips Island), and on bays and river deltas in widespread in substanal numbers in coastal, the Liverpool Bay area. The outer Mackenzie Delta nearshore, and offshore waters of the Beaufort Sea provides criMcal habitat during the autumn LME. The greatest numbers, at least several million, migraMon for black brant. River deltas and adjacent occur in coastal and nearshore zones, with the most coastal wetlands along the North Slope of Alaska, numerous being ducks and geese including eiders notably the Colville and Sagavanirktok estuaries, are and other sea ducks, and various species of also used as nesMng and molMng habitats for geese. shorebirds. Long-tailed ducks are the most abundant and The Cape Bathurst Polynya and the associated leads widespread sea duck throughout the Beaufort Sea along the Toktoyaktuk Peninsula and Banks Island region. During summer, males and non-breeding are used as spring staging and feeding areas for females aggregate in coastal lagoons and bays several species of sea ducks, divers and seabirds where they undergo an extensive feather molt. including common (Pacific) and king eiders, long- Together with lesser numbers of scoters, scaup, red- tailed duck, red-throated diver, Pacific loon, breasted mergansers, and some common eiders, glaucous gull and ArcMc tern. these molMng birds are flightless and vulnerable during this period. Important molMng areas for sea Cliffs are a rare habitat along the southern Beaufort ducks in the eastern Beaufort Sea are the McKinley Sea, and cliffs at Cape Perry in the Amundsen Gulf Bay-Phillips Island and Kukjuktuk and Hutchinson area hold the only breeding colony of thick-billed Bay areas along the Tuktoyaktuk Peninsula, several murre in the Beaufort Sea.