Seeing huge whales in their native habitat counts as one of life's great experiences. Each summer 15-20 humpback whales regularly feed in park waters, concentrating in the lower part of the bay. They migrate here from their winter home in the warm waters off Hawaii and can often be seen along the shorelines of Southeast Alaska. Special regulations go into effect when large concentrations of whales are in the park. The regulations affect vessel speed limits and travel routes in certain areas.

Humpback whales are the most acrobatic of whales, heaving their massive selves by leaps and turns out of the water. Humpbacks are both cosmopolitan—found in all oceans—and endangered. Only about seven percent of their pre-whaling numbers remain. Coastal feeders who love shorelines, bays, and fjords, they are naturals for Alaska, which boasts nearly 34,000 miles of tidal shoreline. Humpbacks feed here on krill, shrimp, and various fish, including capelin. Humpbacks feed heavily because, unlike most birds and mammals, they do not feed year round. Humpbacks must store enough fat in summer to last the rest of the year. Adults average 40 to 50 feet long, females being the larger. Adults weigh in at about three-quarters of a ton per running foot.

An adult humpback has from 600 to 800 baleen plates in its mouth. These plates end in bristles. In the feeding process, huge masses of sea organisms are scooped into the mouth. Then the water, some 150 gallons at a shot, is expelled while the plates filter in the edibles. Were you to stare into a humpback's mouth— which opens to 90 degrees— you might not readily discount the Biblical mishaps of Jonah. Glacier Bay humpbacks have been observed working singly or in pairs to cast a"net" of bubbles about their prey and then harvesting the hapless creatures—probably shrimp and other slower-moving organisms—caught in their airy illusion.

Whales include the largest creatures our world has known. Blue whales weighed up to 200 tons before whaling days. Sixty to 100 million years ago the ancestors of today's whales were land dwelling, warm-blooded, air breathing mammals who successfully returned to the seas to live. Alaskan waters boast 10 species of baleen whales and 5 toothed whales. Glacier Bay waters boast 2 of the baleen whales, the minke and humpback, and 1 toothed whale, the orca. The whales' appeal mixes familiarity and strangeness. Whales live in family groups, aid each other in distress, and talk to each other. Some serious observers credit whales with rational thought.

Minke whales are thought to be quite migratory and are more at home in cold northern waters than most baleen whales. (Baleen whales are named for how they feed). Cod and pollock are their main diet here. Farther south minkes favor krill. The upper size limit of minke whales in northern waters is 33 feet. Among large whales, minkes are fast swimmers, making speeds up to 20 miles per hour. As whaling has depleted more favored species, the rich-meated minke has become the most often killed baleen whales. Their North Pacific population appears to have declined to between one-fourth and one-third its pre-whaling numbers.

Orca whales feed on various marine animals, including fish, sea lions, seals, porpoises, sharks, squid, and other whales. Also called killer whales, orcas can hunt in teams and have killed blue whales, the world's largest animals. Male orca whales average about 23 feet long; the females less. They have no natural enemies. Thought to be highly intelligent, orcas are readily trained in captivity. They can swim at a steady 29 miles per hour. Their distinctive, largely triangular dorsal fin may reach nearly 6 feet high on old males.