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17 Hudson Bay

17 Hudson Bay

17/18: LME FACTSHEET SERIES HUDSON COMPLEX LME

tic LMEs Arc COMPLEX LME 18 of Map Russia

LME Baffin Island ()

Canada Hudson Bay

Iceland

Newfoundland &

17 1 LMEs

Large Marine Ecosystems (LMEs) are defined as of work of the Arcc Council in developing and promong the space of 200,000 km² or greater, that encompass Ecosystem Approach to management of the Arcc marine coastal areas from basins and to the outer environment. margins of a connental shelf or the seaward extent of a predominant coastal current. LMEs are defined by ecological Joint EA Expert group criteria, including bathymetry, hydrography, producvity, and PAME established an Ecosystem Approach to Management tropically linked populaons. PAME developed a map expert group in 2011 with the parcipaon of other Arcc delineang 17 Arcc Large Marine Ecosystems (Arcc LME's) Council working groups (AMAP, CAFF and SDWG). This joint in the marine waters of the Arcc and adjacent in 2006. Ecosystem Approach Expert Group (EA-EG) has developed a In a consultave process including agencies of Arcc Council framework for EA implementaon where the first step is member states and other Arcc Council working groups, the idenficaon of the ecosystem to be managed. Idenfying Arcc LME map was revised in 2012 to include 18 Arcc the Arcc LMEs represents this first step. LMEs. This is the current map of Arcc LMEs used in the This factsheet is one of 18 in a series of the Arcc LMEs.

OVERVIEW: HUDSON BAY COMPLEX LME

The Hudson Bay (HB) complex is a large, Canadian with typical Arcc characteriscs, including cold, dilute waters and complete, seasonal ice cover. Situated between 51° and 71°N latude and 65° and 95°W longitude, it has a sea surface area of 1,242,000 km² and island surface area of 83,000 km². The basin is enclosed by Baffin Island and the Canadian mainland. Its main opening is to the (North Atlanc) via , and there is a smaller connecon to the Arcc Ocean via .

The HB complex is shallow except for Hudson Strait. The seafloor of Map: The Hudson Bay Hudson Bay is comprised of two Complex LME. saucer-shaped basins separated by a ridge-like feature that extends from Source: AMSAIIC Report the south shore and rises to a depth of < 40 m at the Midbay Bank. A broad coastal shelf extends to 80 m depth offshore the coasts of Québec (20-50 km), and Kivalliq (50-70 km), and and the northern islands (100 km). The boom slopes gradually from the shelf across the HB complex from northwest to southeast, to a smooth sea floor with an average depth of 250 beginning in early October in northern , m. Hudson Strait deepens progressively to 1,000 m in spreading into northern Hudson Bay and Hudson the east, north of , and then rises to a sill Strait by mid-October, and finally into southern less than 400 m deep that separates the HB complex and eastern Hudson Strait by early from the Labrador Sea. December. The extent and thickness of the ice increase rapidly during November and December, Hudson Bay is essenally ice-covered in winter and with maximum coverage in late April or early May. ice-free in summer. Most ice forms locally but a small Maximum ice thickness varies but generally amount of mul-year ice enters via Fury and Hecla increases from south to north, ranging from about 1 Strait. Mul-year ice is rare in Hudson Bay and 2 m in to 2 m in northern Foxe absent from James Bay. New ice forms progressively Basin.

MARINE MAMMALS Atlanc and ringed, bearded, and harbour Canadian Arcc area, with a large fracon of them seals inhabit the waters of the HB complex year- occurring in the Hudson Bay Complex. round, while polar bears and Arcc foxes frequent coastal areas in summer and ice habitats during Harbour seal is a coastal and insular seal with wide other seasons. Harp and hooded seals and at least six distribuon in temperate, boreal and sub-Arcc areas species of whales including beluga, bowhead, of both the North Atlanc and North Pacific. Small , killer, minke, and humpback whales are resident populaons of harbour seals occur along the typically seasonal visitors to the , although the coasts of Hudson Bay and James Bay. They are found first three species do overwinter in Hudson Strait and in areas where currents maintain open water year- somemes in leads and elsewhere. The round, typically in freshwater or estuarine rapids, quality, extent and duraon of the cover are small coastal polynyas, or at the ice edge. Harbour vitally important determinants of their seasonal seals occur in many of the larger river systems of distribuons, movements, reproducve success, and southern Hudson Bay including Thleiwaza, Seal, survival. Churchill, and Nelson. There is lile informaon on numbers of harbour seals and their populaon size in The is the most common and abundant Hudson Bay has not been esmated. species of seal in the HB complex, where it is resident year-round. Ringed seals occur in water of virtually Harp seal is a North Atlanc species that occurs with any depth and their distribuons likely are driven three stocks: Northwest Atlanc, / primarily by availability of predator-relief habitat, West Ice, and / stocks. Harp food availability and ice condions. Ringed seals in seals from the large Northwest Atlanc stock are Hudson Bay are relavely small with an asymptoc seasonal visitors to the HB complex which is part of length of about 1.2 m and a weight of about 50 kg. the summer feeding range for these seals. Migratory Ringed seals are adaptable in their feeding habits and harp seals move into Hudson Strait where they are eat a variety of pelagic, nectonic, and benthic common before the shore ice leaves in spring, rare in invertebrates and fishes--parcularly the amphipod summer, and common again in autumn aer the Themisto libellula, the mysid Mysis oculata, polar shore ice forms. Some seals move further west into cod, and sculpins. Sandlance appears to be an northern Hudson Bay and some may also move north important food item for ringed seals in Hudson Bay in Foxe Basin. The fracon of the stock of harp seals while polar cod contribute less to the seal diet here that move into Hudson Strait and Hudson Bay is not than in many other Arcc regions. The total number known but has been considered to be small. The of ringed seals in the Hudson Bay Complex is not Northwest Atlanc stock of harp seals has been (well) known. Smith (1975) esmated a populaon of increasing from a low of about 2 million in the early about 0.5 million ringed seals in Hudson and James 1970s to around 7-8 million in 2010. Associated with Bays. this increase they are possibly re-occupying the former range within the HB complex. is a much larger species than ringed seal, weighing 250-300 kg and measuring 2-2.5 m in Hooded seal is a North Atlanc species found with length. The species has a circumpolar distribuon in two main populaons in the northwestern and ice-covered waters and occurs with two recognized northeastern Atlanc. Seals of the western subspecies for the Atlanc and Pacific sectors. populaon are seasonal visitors to the HB complex. Bearded seals of the Atlanc subspecies are patchily The Northwest Atlanc populaon has three distributed in the HB complex, typically at low whelping areas on pack ice in the ‘Front’ area (off densies relave to ringed seals, in areas of moving southern Labrador and northern Newfoundland), sea ice and open water in depths of less than Gulf of St. Lawrence, and . Some hooded 150-200 m, especially areas in the 25-50 m depth seals migrate via Hudson Strait into northern Foxe range. Bearded seals are found throughout the Basin in July and return south in September. It is not Hudson Bay Complex with the largest numbers known if these are seals that arrive from the molng indicated to occur in Foxe Basin, Hudson Strait and area in the or if they molt on the northern and eastern Hudson Bay. There are no good Canadian side before they move into Foxe Basin. esmates of populaon size of bearded seals in the Hooded seals are uncommon in Hudson Bay and Hudson Bay Complex. Cleator (1996) suggested a James Bay. minimum of 190 thousand bearded seals for the total 3

Atlanc walrus were once widely distributed in the belugas from any of the stocks. The Western and Canadian Arcc from the northern Scoan Shelf to Eastern Hudson Bay belugas are on average smaller the central High Arcc including Hudson Bay. Since than those of the High Arcc and the 1920s there has been a general shi in walrus populaons. This may be a reflecon of the distribuon in the HB complex away from human difference in diets between the Hudson Bay communies to areas that are less accessible. Three populaons and the more northern populaons of Atlanc walrus populaons or stocks have been beluga. idenfied in the HB complex: Foxe Basin, Southern and Eastern Hudson Bay, and Northern Hudson Bay- in Hudson Bay are from the Hudson Bay Davis Strait. The Foxe Basin stock is distributed year- populaon which is considered to be separate from round in the relavely shallow waters of northern the Baffin Bay metapopulaon. These narwhals Foxe Basin. The Southern and Eastern Hudson Bay summer in northwestern Hudson Bay and most of stock is distributed from Cape Henriea Maria in them are believed to winter in eastern Hudson southern Hudson Bay north through the Belcher and Strait. Narwhals migrate out of Hudson Strait to Sleeper islands to the Oawa Islands in eastern winter east of Resoluon Island in the southwestern Hudson Bay. Born et al. (1995) suggested that the Davis Strait area. This wintering area is separated stock sizes were about 5.500 walrus for the Foxe geographically from those of the Baffin Bay Basin stock, about 6.000 for the Northern Hudson subpopulaons in Baffin Bay and northern Davis Bay-Davis Strait stock, and possibly around 500 Strait, which is one reason why Hudson Bay animals for the Southern and eastern Hudson Bay narwhals are considered to be a disnct and stock. COSEWIC (2006) reviewed these esmates separate populaon. Westdal et al. (2009) esmate but there were lile new informaon available to a Narwhal populaon of about 5.600 individuals for provide a basis for new esmates. the HB complex.

Beluga whales of 3 (or more) populaons are found The only baleen whale that occurs commonly in the in the Hudson Bay Complex. The Western Hudson HB complex is the bowhead, and it is seldom seen in Bay populaon is the largest, with its main southern Hudson Bay and James Bay. The HB summering areas along the coast of southwestern complex is used by bowheads as wintering, Hudson Bay. The Eastern Hudson Bay populaon has migraon, summer feeding, and nursery areas. its summering area along the coast of the Nastapoka Prince Regent Inlet has historically been known as a Arc, inside of . These two populaons main nursery area for bowheads, and many or most have their main wintering areas in Hudson Strait and of the whales that summer here, are believed to adjacent areas. The Ungava Bay populaon had a return through Fury and Hecla Strait and Foxe Basin, restricted distribuon in Ungava Bay along including bowheads that have entered through southeastern Hudson Strait. . The populaon of bowheads in Baffin Bay and Hudson Bay was severely depleted by Belugas make use of most of the the commercial that ended a century ago. LME while foraging or during migraon between Close to 30,000 individuals were killed in Baffin Bay summering and wintering areas. From the main and Davis Strait over a 200-years period from 1719 wintering areas in Hudson Strait, belugas migrate in to 1915, with lower numbers taken in Hudson Bay spring along ice leads into Hudson Bay. Some also and Foxe Basin. The number of bowheads remain year- round to winter in polynyas and leads 4 summering in Hudson Bay and Foxe Basin is not well in Hudson Bay. The central porons of Hudson Bay known. and most of Foxe Basin appear not be much used by Atlanc walrus were once widely distributed in the Belugas make use of most of the Hudson Complex Canadian Arcc from the northern Scoan Shelf to LME while foraging or during migraon between the central High Arcc including Hudson Bay. Since summering and wintering areas. From the main the 1920s there has been a general shi in walrus wintering areas in Hudson Strait, belugas migrate in distribuon in the HB complex away from human spring along ice leads into Hudson Bay. Some also communies to areas that are less accessible. Three remain year- round to winter in polynyas and leads Atlanc walrus populaons or stocks have been in Hudson Bay. The central porons of Hudson Bay idenfied in the HB complex: Foxe Basin, Southern and most of Foxe Basin appear not be much used by and Eastern Hudson Bay, and Northern Hudson Bay- belugas from any of the stocks. The Western and Davis Strait. The Foxe Basin stock is distributed year- Eastern Hudson Bay belugas are on average smaller round in the relavely shallow waters of northern than those of the High Arcc and Cumberland Foxe Basin. The Southern and Eastern Hudson Bay Sound populaons. This may be a reflecon of the stock is distributed from Cape Henriea Maria in difference in diets between the Hudson Bay southern Hudson Bay north through the Belcher and populaons and the more northern populaons of Sleeper islands to the Oawa Islands in eastern beluga. Hudson Bay. Born et al. (1995) suggested that the stock sizes were about 5.500 walrus for the Foxe Narwhals in Hudson Bay are from the Hudson Bay Basin stock, about 6.000 for the Northern Hudson populaon which is considered to be separate from Bay-Davis Strait stock, and possibly around 500 the Baffin Bay metapopulaon. These narwhals animals for the Southern and eastern Hudson Bay summer in northwestern Hudson Bay and most of stock. COSEWIC (2006) reviewed these esmates them are believed to winter in eastern Hudson but there were lile new informaon available to Strait. Narwhals migrate out of Hudson Strait to provide a basis for new esmates. winter east of Resoluon Island in the southwestern Davis Strait area. This wintering area is separated Beluga whales of 3 (or more) populaons are found geographically from those of the Baffin Bay in the Hudson Bay Complex. The Western Hudson subpopulaons in Baffin Bay and northern Davis Bay populaon is the largest, with its main Strait, which is one reason why Hudson Bay summering areas along the coast of southwestern narwhals are considered to be a disnct and Hudson Bay. The Eastern Hudson Bay populaon has separate populaon. Westdal et al. (2009) esmate its summering area along the coast of the Nastapoka a Narwhal populaon of about 5.600 individuals for Arc, inside of Belcher Islands. These two populaons the HB complex. have their main wintering areas in Hudson Strait and adjacent areas. The Ungava Bay populaon had a The only baleen whale that occurs commonly in the restricted distribuon in Ungava Bay along HB complex is the bowhead, and it is seldom seen in southeastern Hudson Strait. southern Hudson Bay and James Bay. The HB complex is used by bowheads as wintering, migraon, summer feeding, and nursery areas.

5 Killer whale is now a regular summer visitor to the crack and re-freeze. They move onto the ice when it northwestern Hudson Bay and Foxe Basin. forms in the fall and travel widely unl melng Historically killer whales were not known to occur forces them ashore to fast unl freeze-up. The ice in the Hudson Bay region, despite extensive clearance paern combined with site fidelity to observaons during the bowhead whaling period in denning areas contributes to the separaon of the 1800s and early part of the 1900s. There were a subpopulaons in the HB Complex. The ice few sighngs from Hudson Strait in the early part of generally clears from north to south in Hudson Bay, the 1900s, with a marked (exponenal) increase in opening first in the eastern and northwestern parts, the number of sighngs in Hudson Bay aer 1940. and with the last ice to melt away usually found in The increased occurrence of killer whales in Hudson southern Hudson Bay off the coast of Ontario. Bay followed a change to lighter ice condions with earlier break-up in Hudson Strait, which may have Polar bears from western and southern Hudson Bay served as a blocking ‘choke point’ for killer whales have tended to be larger than bears from other previously. Killer whales in the Hudson Bay region subpopulaons in the Canadian Arcc. Polar bears appear to be of the mammal eang ecotype, and of the Western Hudson Bay subpopulaon were they have been reported to prey on narwhal, found also to have higher reproducve rates than beluga, bowhead, and seals. The number of killer populaons further north, with 40% of the females whales that use the Hudson Bay region for summer having a two-year rather than a three-year feeding is not known reproducve cycle, weaning the cubs aer 1.5 year. With earlier break-up of ice in spring or early Polar bears from three subpopulaons inhabit the summer, the period of spring feeding on ringed seal Hudson Bay Complex: the southern Hudson Bay, pups becomes shorter and the period on land western Hudson Bay, and Foxe Basin fasng with lile or no food becomes longer. This subpopulaons. In addion, bears from a fourth has been associated with bears of the Western subpopulaon, the Davis Strait subpopulaon are Hudson Bay subpopulaon coming ashore in poorer found in the eastern part of Hudson Strait and condion and having lower reproducve success. Ungava Bay. The most important factor affecng the The Western Hudson Bay subpopulaon seasonal distribuon and movement of polar bears was recently (2004) esmated to be about 950. The is the seasonal variaon in sea ice condions. Bears Southern Hudson Bay subpopulaon was recently rely on the ice to provide a travel plaorm for esmated to be about 700 bears in 2005. The Davis hunng ringed and bearded seals, and prefer areas Strait subpopulaon was esmated to be about where wind, water currents or des cause the ice to 2.100 bears in 2006.

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FISH WATERFOWL

Knowledge of fishes in the HB complex is scant Large areas of the Hudson Bay and James Bay coasts except for harvested anadromous species, and in provide crically important habitat for migrang the vicinity of large estuaries. Lack of a proven, and moulng North American waterfowl. During commercial offshore fisheries resource has limited the breeding season most of these waterfowl - offshore fisheries research, and ice condions have frequent low lying near lakes or coastal limited seasonal research. river mouths. Low-lying coasts with important habitats for waterfowl are also found on islands in At least 61 species of fish use the waters of Hudson/ the northern Hudson Bay and in the Foxe Basin, as James Bay—fewer than are present in Hudson Strait well as along western Baffin Island from the Foxe (89) and along the Atlanc coast. Very lile is Peninsula north to Taverner Bay. Costal habitats are known of the fishes in Foxe Basin. Species richness important post-breeding feeding areas for many and abundance increases in an easterly direcon waterfowls including molng ducks and geese. They through Hudson Strait. James Bay and southern are also important staging areas for migratory Hudson Bay support characterisc and unusual waterfowls, including populaons of sea ducks and estuarine fish communies that consist of a mixture geese that breed further north in the Canadian of Arcc marine, estuarine, and freshwater species. Arcc Archipelago and the northern Baffin Bay area. Estuarine communies in the south include more The vast majority of waterfowl are migratory and freshwater and anadromous species and fewer leave the Hudson Bay Complex to winter either on Arcc and deepwater species than those to the coasts or inland further south in . north. The Hudson Bay Complex spans a wide range of o Warm, shallow, dilute estuaries along the latudes (from 52 to 70 N) and climac condions, coast, from the River north to Lac and the number of species generally decreases from Guillaume Delisle (Richmond Gulf), aract typically south to north. A total of 33 species of waterfowl freshwater species such as lake trout, lake are common or regular breeders in this LME. They whitefish, lake cisco, and burbot. Further north and include 12 species of sea ducks, 7 dabbling ducks, 3 moving offshore, where the salinity is higher and diving ducks, 6 geese, one swan, and 4 species of water colder, there are fewer freshwater species divers. The most numerous and widespread are and more Arcc species such as Arcc charr, common and northern eider, long-tailed duck, red- Greenland cod and shorthorn sculpin. The estuaries breasted merganser, , snow goose, provide important seasonal foraging and nursery and red-throated diver. habitat for many species, spawning habitat for some, and year-round habitat for fourhorn sculpin. Offshore, the relavely shallow depths in James Bay, Hudson Bay, and much of Foxe Basin likely exclude many of the deepwater fishes that occur in Hudson Strait, including commercially valuable species such as the (turbot) and redfish.

In boom trawls of eastern Hudson Strait, Arcc cod are dominant in terms of numbers and Greenland halibut in terms of weight; in western Hudson Strait they are replaced by lumpfish and seasnails. Small, shallower water species such as capelin and Arcc cod are vital links in the food chain of the HB complex between pelagic invertebrates and larger fish, marine mammals and birds. Large numbers of capelin spawn on beaches in the Belcher Islands and near the in June. Arcc cod are oen associated with ice cracks of edges and move inshore in late summer, somemes in very large schools. Larval Arcc cod are very common in the coastal waters of 7 southeastern Hudson Bay.

SEABIRDS SHOREBIRDS The Hudson Bay Complex LME provides resources The Hudson Bay Complex offers extensive habitats of crical naonal and internaonal importance to for shorebirds parcularly along lowlying coastlines migratory , waterfowl, and shorebirds. Few where high dal ranges provide large areas of species remain year-round due to the near interdal flats adjacent to tundra and . complete ice cover. The Hudson Bay Complex LME These provide important breeding, feeding and provides breeding habitats and feeding grounds for migraon habitats for a large number of shorebirds several species, and serves also as of many species. The wide latudinal range from migraon area and to lesser extent as wintering southern James Bay (52oN) to northern Foxe Basin habitat for seabirds and other birds. Eleven species (at about 70oN) spans a wide range of of seabirds are regular breeders in this LME (2 auks, environmental condions from northern boreal to 5 , Arcc tern, and 3 skuas. The most abundant near high arcc, contribuon to a high diversity of breeder by far is the thick-billed murre (670,000 shorebirds in this LME. pairs), which constute 90% of the summer seabird biomass in northern Hudson Bay and Hudson Strait About 27 species breed regularly around the and supports the third-largest seabird community coastlines of the Hudson Bay Complex. These in the Canadian Arcc. The seabirds migrate into comprise 10 calidrine sandpipers, 3 phalaropes, the region mostly from the east via Hudson Strait. ruddy turnstone, 4 plovers, 3 godwits and curlews, In contrast, waterfowl and shorebirds typically 4 shanks, and 2 snipes and dowitchers. All the enter from the south via James Bay or southern shorebirds are migratory and leave the Hudson Bay Hudson Bay. Complex to winter at lower latudes and in . The extremely flat shorelines of southern Hudson Bay and western James Bay combined with relavely large dal ranges result in very wide dal flats, extensive eelgrass beds and rich coastal marshes make it one of the most important stopping places in North America for migrang 8 Arcc-breeding waterfowl and shorebirds. ARCTIC LMEs 1. Faroe Plateu LME 2. Iceland Shelf and Sea LME 3. Greenland Sea-East Greenland LME 4. LME 5. Barents Sea LME 6. LME 7. LME 8. LME 9. East LME 10. Aleuan Islands LME 11. West Bering Sea LME 12. Northern Bering- LME 13. Central Arcc Ocean LME 14. LME 15. Canadian High Arcc - North Greenland LME 16. Canadian Eastern Arcc - West Greenland LME 17. Hudson Bay Complex LME 18. Labrador-Newfoundland LME

LITERATURE REFERENCES Acknowledgements • The 2007 assessment of Oil and Gas in the Arcc (OGA) - PAME gratefully acknowledges the financial AMAP (2007) support provided to this project by the Nordic • AMAP OGA 2007 - Updated descripon of the Barents Sea Council of Ministers and the OAK Foundaon. LME. Lead author: Hein Rune Skjoldal. • Arcc Marine Areas of Heightened Ecological and Cultural Significance: Arcc Marine Shipping Assessment (AMSA) IIC - AMAP/CAFF/SDWG (2013) • Large Marine Ecosystems (LMEs) of the Arcc area Revision of the Arcc LME map - PAME (2013) Text: David J. Prieto

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