ABSTRACT
Many large whales in the Northern Hemisphere migrate long distances between their calving areas to the south and their northern feeding grounds. Some swim very near shore during at least part of this annual migration. The eastern Pacific gray whale population winters in lagoons and coastal areas of Baja California, Mexico, where calving and mating occur, and then migrates north along the west coast to North America to northern Alaskan waters, where the whales feed during summer and autumn. From their wintering grounds in the westcentral Bering Sea, bowhead whales migrate north in spring to summer feeding areas in the Arctic Ocean. During this migration they move through openings in the sea ice, called leads, which regularly occur close to shore at certain locations.
