Western Alaska - More Information

Background information on the Western Alaska/Aleutian - Bering Sea Islands region, a DU conservation priority area

Western Alaska (Region 1*) consists of the Subarctic Coastal Plain from Kotzebue Sound and Seward Peninsula to the Bristol Bay lowlands. The coastline includes the Norton Sound, Bering Sea islands, Bristol Bay, and the Yukon-Kuskokwim Delta which is the largest riverine delta in western North America. The Norton Sound contains 16 lagoons (over 88,000 ha), 2 large tidal river mouths (over 2,100 ha), 49 rivers, and 386 streams. The four Bering Sea islands (St. Lawrence, Nunivak, St. Matthew and the Pribilofs) contain 37 lagoons (over 37,000 ha), 40 rivers, and nearly 400 streams. Bristol Bay (including the Alaska Peninsula) contains 31 lagoons (over 206,000 ha), 3 large tidal river mouths (nearly 16,000 ha), 56 rivers, and 749 streams. The Yukon-Kuskokwim Delta contains 13 lagoons (over 103,000 ha), 22 large tidal river mouths (over 141,000 ha), 171 rivers, and nearly 2,100 streams. Overall, this region contains over 9.7 million ha of salt water less than 18 m in depth, 10,881 km of shoreline, 97 lagoons with an area greater than 435,000 ha, 27 large tidal river mouths with an area nearly 160,000 ha, some 534,000 ha of unvegetated intertidal zone, over 1 million ha of vegetated intertidal zone, 316 rivers, and over 3,600 streams (King and Dau 1981). The wet and moist tundra of the Subarctic Coastal Plain is dominated by sedges, grasses, and mosses, with numerous lakes and ponds.

The Yukon-Kuskokwim Delta is one of the most important waterbird areas on the continent. Within 60 km of the coast this area is directly impacted by tidal action, but annual precipitation, river action, and permafrost play significant roles in wetland function. Wet meadows and sedge marshes are interspersed throughout the volcanic Aleutian Islands. The Alaska Peninsula is a 48,000 km2 area extending from Becharof Lake to Dutch Harbor and is dominated by dwarf scrub, moss/lichen, tall riparian, and sedge wetlands. The peninsula has a coastline longer than that of the conterminous United States, and includes Izembek Lagoon which contains 34,000 ha of eelgrass (one of the largest eelgrass beds in the world).

*Region 1 - NABCI Bird Conservation Regions 1 & 2

Importance to waterfowl

Yukon-Kuskokwim Delta, Bristol Bay lowlands, Kotzebue Sound, Izembek Lagoon, and the Aleutian and Bering Sea Islands are the most important waterfowl areas of this region. The Yukon Delta has an estimated breeding population of 1.3-1.7 million ducks, nearly the entire population of emperor and cackling Canada geese, and nearly 70% of the continental population of black brant (King and Lensink 1971). Density of ducks (1989-91) in subarctic tundra (20.5 pairs/mi2) is lower than encountered in boreal forest (24.5 pairs/mi2) or arctic tundra (33.1 pairs/mi2) regions (Conant and Dau 1991). Dominant breeding species in the Bristol Bay according to U.S. Fish and Wildlife Service (USFWS) surveys include scaup (nearly 130,000), scoter (>75,000), mallard (69,000), green-winged teal (>61,000), northern pintail (>59,000), and American wigeon (>46,000). Dominant species in the Yukon Delta include northern pintail (>362,000), green-winged teal (> 263,000), scaup (>254,000), northern shoveler (>181,000), mallard (>157,000), and tundra swan (>116,000). Dominant species in the Seward Peninsula include northern pintail (>131,000), northern shoveler (>53,000), American wigeon (>41,000), and scaup (>33,000). Dominant species in the Kotzebue Sound include American wigeon (>147,000), northern shoveler (>142,000), northern pintail (>112,000), mallard (nearly 93,000), and scaup (>80,000).

Sea ducks (primarily eiders, long-tailed ducks, and scoters) winter in large assemblages along the Alaska Peninsula, Aleutian, Bering Sea, and Kodiak Islands. Single flocks may reach several 100,000 birds, and several million sea ducks winter in this region. This region, combined with the shore of the Arctic Coastal Plain, is the most important area for sea ducks in North America. More than nine million waterfowl are heavily dependent on Bering Sea habitats during their annual cycle, which accounts for approximately 11% of the continental populations (King and Dau 1981). Six species including cackling Canada goose, emperor goose, and Aleutian Canada goose use these areas exclusively (King and Dau 1981). The 15,720 km2 of intertidal habitat found on the eastern Bering Sea coast is probably not duplicated elsewhere on the continent in an area of comparable size. It is not uncommon to find densities of nesting waterfowl, primarily geese, in excess of 57/km2 in the intertidal habitat of the Yukon Delta (King and Dau 1981). The Aleutian Islands contain habitat for the only North American population of European common teal, and Eurasian wigeon breed in the coastal Yukon Delta.

Importance to other birds

Even without its large populations of waterfowl, the Yukon Delta would be unique for its large populations of waterbirds (King and Lensink 1971). Arctic and red-throated loons are common breeders, as are bar-tailed godwits, dunlins, western sandpipers, northern and red phalaropes, and black and ruddy turnstones. Coastal habitats provide key staging areas for bristle-thighed curlews and whimbrels during late summer (King and Lensink 1971). Colonies of sea birds have been described at 135 locations in the Gulf of Alaska and the Bering Sea, exclusive of the Aleutian Islands (King and Lensink 1971). At least 26 colonies contain more than 100,000 breeding birds and several contain more than a million. Dominant sea bird species include red-faced and pelagic cormorants, red-legged and black-legged kittiwakes, Aleutian terns, Kittlitz’s murrelets, horned puffins, and least and whiskered auklets. This region is the most important area for alcids and kittiwakes in western North America.

Environmental risks

The principal risk in this area is contamination of near shore waters. Petroleum exploration has been stopped in recent years by a drilling moratorium. There are numerous offshore wells in the Bering Sea, but the greatest risk is from maritime shipping, especially international ships that are not kept to the same standard as U.S. or Canadian vessels. Floating petroleum in the near shore waters or the principal lagoons of the Bering Sea could destroy large numbers of geese and sea ducks (King and Dau 1981). Similarly, oil cast by storm tides into the nesting habitats of the Yukon Delta could cause considerable waterfowl mortality (King and Dau 1981). Marine terminals for oil storage have been proposed for western Alaska, even at Izembek Lagoon. Digital landcover maps of this region are critical for resource managers to make sound management decisions. Existing landcover maps will facilitate planning or execution of hazardous material containment. Through pro-active delivery of landcover scenes, change detection is feasible if significant spill occurs.

Current conservation programs

Ducks Unlimited has digitally mapped wetlands and associated uplands through remote sensing of the Lake Iliamna region at the base of the Alaska Peninsula and near coastal areas of Norton Sound. Little digital landcover data exists for the vast majority of this region. Partnerships with the Alaska Science Center, USFWS, and University of Alaska have resulted in research efforts on brant, cackling Canada goose, emperor goose, greater scaup, and spectacled eider.

Goals

  • To complete wetland habitat mapping on at least 10,121,000 ha. Areas of importance include Selawik, Yukon Delta (over 7,692,000 ha), Togiak, Alaska Peninsula, Kodiak, and Izembek National Wildlife Refuges (NWRs); Bering and Aleutian Islands (especially St. Lawrence Island); Bering Land Bridge and Katmai National Park (NP).
  • To complete analyses of waterbird associations with landcover, especially in core areas such as Yukon Delta. To aid in risk assessment of potential oil damage in core lagoons.
  • To assist in research on coastal tundra ecology, sea duck, brant, and emperor goose ecology, and habitat use by northern pintail and scaup.
  • To aid resource managers, principally USFWS and First Nation, in positive management decisions.

Assumptions

  • Dramatic population declines for several species of sea ducks have been observed, but causes are unknown.
  • This vast region has specific core areas that are important for waterbirds, but many of the specific locations are poorly known or understood.
  • Changes in population structure may be due to conditions on wintering or migration areas.
  • Reduction in subsistence harvest (Hooper Bay agreement) has had a substantial influence on the recovery of several goose populations.

Strategies

  • Expand partnerships with developed image classification protocol and technology of waterbird habitat use and relationship to fire histories with USFWS, Alaska Science Center, Alaska Fire Service, and First Nations on the Yukon Delta and Alaska Peninsula regions.
  • Pursue research projects with Alaska Science Center and Universities on tundra ecology, northern pintail, greater scaup, sea duck, and emperor goose ecology, and the relationship that Bering Sea marine environments play to western Alaska waterbird habitats.
  • Focus on gaining critical resource information that can be used for risk assessment of potential degradation.