Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Temperate and subarctic regions of the Northern Hemisphere. In the western North Atlantic, breeds at least from Cape Dorset on southwestern Baffin Island to Massachusetts; occurs along west coast of Greenland as far north as Disko Island and Avanersuaq, along the east coast to Ittoqqortormiit (Teilman and Dietz 1994); small numbers occur, mostly in river mouths, in parts of Hudson Strait, Ungava Bay, and Hudson Bay; small local populations inhabit some rivers and lakes of western Hudson Bay, moving as far as 240 km inland; small population occurs in the Lacs des Loups Marins (Seal Lakes) at the headwaters of the Nastapoka River in northern Quebec; large population breeds on Sable Island, 125 km off Nova Scotia; extirpated from Lake Champlain and Lake Ontario; sometimes ranges as far north as Ellesmere Island and as far south as Florida (Reeves et al. 1992, which see for distribution in eastern North Atlantic. In the eastern Pacific, breeds from Bahia San Quintin, Baja California, to Aleutian Islands, Pribilof Islands, and Nome, Alaska; in the western Pacific, Commander Islands south to Hokkaido, Japan (Reeves et al. 1992). In eastern North Atlantic, ranges from Murmansk to the outer Baltic and northern France, United Kingdom south to east Anglia, southern Ireland, Faroes, Spitsbergen, and Iceland (McLaren, in Macdonald 1985).