North Pacific High Sea

The eastern Bering Sea lies over a broad continental shelf, its waters opening toward Bristol Bay and the Yukon-Kuskokwim coast. In winter sea ice advances across the shelf; in spring it breaks and retreats, changing the feeding and resting grounds of marine mammals and birds. The edge of the ice also affects the exchange of heat between sea and air, giving these northern waters a character distinct from the open Pacific beyond the Aleutians.