The Region and its Avifauna
The region discussed here encompasses nearly half of the United States and Canadian coastlines, extending from Washington to the eastern edge of the Northwest Territories. Alaska alone has two-thirds of the United States' continental shelf (Bartonek et al. 1971). This region's marine and estuarine waters are some of the most productive in the world and support a diverse wealth of bird life throughout the year. Sanger (1972), for example, estimated total summer standing stocks of some 21 million birds in an area approximating the outer continental shelf from the Bering Strait south along the coasts of the Aleutian Islands and North America to central California. Sanger and King (this volume), to whom more data were available, revised this estimate upward to 45 million. Bartonek et al. (1974) provided estimates of year-round standing stocks of 27 million birds in the Bering Sea alone.
North and east of the Bering Strait, population estimates of the bird fauna are less complete. Swartz (1966) estimated, however, that seabird populations of five colonies in the vicinity of Cape Thompson in the Chukchi Sea exceeded a total of 420,000 breeding birds in 1960. Information provided by Bartonek and Sealy (this volume) indicates that large colony complexes at Cape Lisburne and Little Diomede Island each number, in aggregate, over 1 million breeding birds, mainly alcids, kittiwakes (Rissa spp.), gulls (Larus spp.), fulmars (Fulmarus glacialis), and cormorants (Phalacrocorax spp.). Although the Chukchi Sea coast north of Cape Lisburne has no rocks suitable for cliff-nesting seabirds, large numbers of tundra-nesting species use the inshore waters as a migratory pathway, and many nonbreeding cliff nesters summer in these waters (J. M. Scott, comments by Pacific Seabird Group on U.S. Department of the Interior Draft Environmental Statement 74-90). According to Scott, sea ducks and gulls are the most numerous birds in the Beaufort Sea. Observations by Thompson and Person (1963) of an estimated 1 million eiders, mostly king eiders (Somateria spectabilis) and Pacific eiders (S. mollissima), passing over Point Barrow en route to molting areas, reflect the numbers involved. Oldsquaws (Clangula hyemalis) use coastal waters of the Beaufort Sea for postbreeding wing molts; Bartels (1973) estimated their numbers at nearly 400,000 in the fall and perhaps more during the molting period. Shorebirds, jaegers (Stercorarius spp.), gulls, and terns, most of which use coastal waters at some time during the summer season, swell bird numbers by several millions in this area (Arctic Institute of North America 1974).
As indicated by Sanger (1972), the seabirds inhabiting coastal areas south of Bering Strait are mainly members of the Procellariidae in summer and Alcidae in winter. Sooty shearwaters (Puffinus griseus) are the prevalent summer species and ancient murrelets (Synthliboramphus antiquus) and marbled murrelets (Brachyramphus marmoratus) are the most abundant winter species. Sanger's central subarctic domain (offshore waters including the Gulf of Alaska) had a different species composition. During the summer, procellariids—mostly slender-billed shearwaters (Puffinus tenuirostris) and sooty shearwaters—made up 94% of the biomass. Procellariids, including fulmars, larids (largely glaucous-winged gulls, Larus glaucescens), black-legged kittiwakes (Rissa tridactyla), and large alcids, including the tufted puffin (Lunda cirrhata), made up 87% of the winter biomass in this domain (Sanger 1972).
Although most of the arctic waters, including the Bering, Chukchi, and Beaufort seas, are unavailable to birds during the winter because of pack ice, they seasonally host an avifauna dominated by colony nesters, such as common and thick-billed murres (Uria aalge and U. lomvia), and tundra nesters, such as oldsquaws and eiders. In far northern waters, sea ducks (mainly eiders and oldsquaws), red phalaropes (Phalaropus fulicarius), and gulls are the predominant species.
Intertidal areas throughout the Alaska, British Columbia, and Washington coasts support characteristic assemblages of shorebirds, including the black oystercatcher (Haematopus bachmani), rock sandpiper (Erolia ptilocnemis), wandering tattler (Heteroscelus incanum), surfbird (Aphriza virgata), and black turnstone (Arenaria melanocephala) as reported by J. M. Scott (comments by Pacific Seabird Group to U.S. Department of the Interior Draft Environmental Statement 74-90). Perhaps the greatest concentrations of shorebirds in this whole region occur during spring and fall migrations in Prince William Sound. The tremendous numbers of migrating birds using these tidal and marsh areas are hard to imagine, but densities of up to 250,000 shorebirds per 259 hectares (ha) on portions of the more than 51,820-ha tidal flats of the Copper River Delta have been recorded (Isleib and Kessel 1973).
Although this region's avifauna is remarkable from the numerical standpoint, it is important to remember also that some of its species are limited in distribution to this area. According to Bartonek et al. (1971), Alaska is the only known breeding area for black turnstones, bristle-thighed curlews (Numenius tahitiensis), surfbirds, western sandpipers (Ereunetes mauri), and Kittlitz's murrelets (Brachyramphus brevirostris). Several waterfowl species, including the dusky Canada goose (Branta canadensis occidentalis), cackling Canada goose (B. c. minima), Aleutian Canada goose (B. c. leucopareia), and Aleutian common teal (Anas crecca nimia) nest only in Alaska coastal areas (Bartonek et al. 1971). Izembek Lagoon on the Alaska Peninsula annually hosts the entire population of black brant, Branta nigricans (Hansen and Nelson 1957), and many other waterfowl, seabird, and shorebird species nest or live in this region in numbers important to their worldwide welfare.
Current and Planned Resource Development
The immense nonrenewable resource wealth of Alaska and other arctic regions has remained virtually unrecognized or unexploited until recently because of the availability of these resources in more accessible locations. As supplies have diminished or been exhausted elsewhere and demands have increased, however, it has become economically feasible or necessary to tap supplies in less-accessible regions. For this reason, the petroleum industry has recently expanded its exploratory efforts in the far North with well-known success. Deposits of metallic ores, coal, and other raw materials to feed industry have likewise been discovered and plans devised for their extraction and sale. Pressed with decreased availability of commercial timber elsewhere, the logging industry has similarly begun to broaden its efforts into Alaska. Expansion of industrial activities into the North is proceeding at a rapidly accelerating pace, and these industries, their associated support industries, and expanded human populations are having and will continue to have unprecedented impact on these marine ecosystems, including their avifauna.