Often longer than a school bus and weighing 30 to 40 tons, gray whales move in large pods as they travel more than 12,000 miles from Mexico to Alaska and back. With a feeding pattern that is unique among whales, the gray whale consumes bottom-dwelling crustaceans and krill by turning on its side and scooping up huge amounts of sediment from the sea floor. The whale separates the food by filtering out the water and sediment through its sieve-like baleen.
Climate Change Impacts
Rises in sea temperature have degraded the gray whale’s Arctic feeding grounds, so that a food supply formerly estimated to support 90,000 whales can no longer feed even the estimated 22,000 roaming the Pacific Ocean. As a result, scientists are reporting more cases of thin adults and dying calves—signs that changes are occurring in their northern feeding grounds. Since gray whales stir up huge amounts of food sediments when they feed, the decline in their population also means less food for seabirds that depend on the dredged food sediments.