Named because of their mottled grey color and the fact that they possess whale lice and barnacles in light-colored areas along their bodies, grey whales feed during the summer months over the continental shelves of the Chukchi and Bering Seas that separate Alaska from Russia. The eastern Pacific population of about 22,000 grey whales winters off the west coast of Canada, Western U.S. and Mexico. The nearly extinct group of 130 grey whales in the western Pacific group is thought to winter off the east coast of China.
New England whaling fleets of the 1800s hunted the North Atlantic grey whale population to extinction. Remains of these whales have been found in the Mediterranean Sea, where a sighting in 2010 off the coast of Israel made some scientists hope that the repopulation of grey whales might be possible. This same whale was spotted off Spain’s coast and is thought to have traveled from the Pacific Ocean through the increasingly ice-free Northwest Passage.
Grey whales reach 14.9 meters (49 feet) in length and weigh up to 36, 300 kilograms (40 tons). Females of this baleen whale are larger than males. Instead of a dorsal fin, the grey whale has six to 12 raised bumps, or knuckles, on top of the last quarter of the body, before the tail. Like other baleen whales, greys strain their food through baleen plates. But, unlike most whales, the grey seeks its food from the ocean floor of the Arctic. The grey whale has a tongue weighing about a ton that dislodges food from its baleen after scooping up ocean sediment. Dives last up to 30 minutes with grey whales dropping 155 meters (508 feet) below the sea’s surface.
These large whales sleep on the ocean’s surface, with just their blowholes exposed to the air. They do not sleep during their 16,000 kilometer (10,000 mile) migration, but, instead, swim day and night until they reach their summer feeding grounds in the Arctic or the winter grounds where four-meter (13-foot) calves are born. Grey whales live about 50 to 60 years.