During the brief arctic summer, dozens of species of migrating birds make use of the unpredictable sections of open water that appear in the ecozone. As the pack ice breaks up, ice edges become vital areas for mammals and seabirds. Taking advantage of the conditions there to feed, stage, and moult are small numbers of Tundra Swans, loons, geese, ducks, and several species of shorebirds, gulls, Jaegers, Arctic Terns, Alcids, and Fulmars.

Polar Bears and Ringed Seals roam throughout the region. Bearded and Harp Seals are found along the east coast of Ellsemere Island, where open waters promise easy breathing. In winter, the unfrozen North Water Polynya serves as a refuge for marine mammals. In the 19th and early 20th centuries, whalers hunted the Bowhead Whale almost to extinction. While their numbers have rebounded in western waters, the eastern stock is still severely depleted and the species is considered endangered.

Large schools of small Arctic Cod exist across the ecozone supporting populations of seals, Beluga Whales and Narwhals. It has been estimated that seabirds and marine mammals consume 148,000 tonnes of these fish annually in Lancaster Sound alone. Arctic Char are plentiful in the Queen Maud Gulf, shrimp thrive in the south Baffin and Hudson Strait waters, and scallops are found off south Baffin Island and in Hudson Bay.

Important but threatened pods of the Beluga Whale spend their summers along the west coast of Hudson Bay. The largest population of Polar Bears in Canada builds dens along the coast of Hudson Bay near Churchill, Man. The tidal flats and salt marshes of the bay also welcome some of the world's largest concentrations of breeding and migrating waterfowl. One of the largest known populations of Peregrine can be found along the northwest coast.