The eastern North Pacific stock of gray whales prefer shallow, coastal waters and feed over oceanic continental shelves around the northern Bering and southern Chukchi seas between Alaska and Russia during the summer. In the winter, many of these gray whales migrate to the warm waters of Mexico's Baja California. They migrate each year along the entire West Coast of the U.S., Canada, and Mexico. The eastern North Pacific stock of gray whales were recently taken off the U.S. List of Endangered and Threatened Wildlife. Although the Atlantic stock of gray whales is basically extinct, the Eastern Pacific stock is doing well.
Gray whales carry whale lice and parasitic barnacles that look like crabs.
These parasites create yellow and white patches on the whales. Instead of a dorsal fin, gray whales have 9-13 bumps along their dorsal ridges. It is thought that gray whales probably have excellent hearing, especially at low frequencies, which is valuable in the dark ocean environment where vision is less useful. Gray whales filter their food through coarse baleen plates. Gray whales are unique in that they prefer prey that live near or on the sea floor.