Frederick Sound is a large body of water near the Norweigan fishing village of Petersburg, Alaska. It encompasses an 80 mile area running from the mouth of the Stikine River Delta to the confluence of Chatham Strait and lower Stephens Passage.
The marine environment near Petersburg, Alaska is abundant with North Pacific sea life. There exists an abundantly rich ecosystem consisting of plankton, fish, and marine mammals. Because of this richness of marine life, the waters of Frederick Sound are primary feeding grounds for migratory humpback whales who come here each spring to feed and frolic in preparation for their fall return to Hawaii for the birth of their calves. The local waters are key to the survival of this ocean giant. Orcas, sea lions, seals, and porpoises also call the local waters home.
Of the estimated 6,000 humpback whales in the North Pacific, approximately 1,000 feed in Southeast Alaska during the summer. Nearly half of the Southeast Alaska feeding population, or approximately 500 whales, will enter the Frederick Sound area during the summer. They are after the very abundant herring and krill (shrimp-like crustaceans) which thrive in these waters. This makes Frederick Sound one of the best places in the world for observing the feeding behavior of humpback whales.
Steller sea lions, harbor seals, Dall’s porpoise, and orcas (killer whales) are also frequently seen in Frederick Sound. The area contains two major and several minor sea lion haulouts. Sea lions and humpback whales are often seen in the same feeding locations and interaction between these species is common. Harbor seals are seen in the water, on the icebergs and in the many rocky islets. A rich diversity of invertebrates adorn the tide pools, and a variety of seabirds are also present in the water and along the coastlines.
With the waters prolific with marine activity, teams of researchers, wildlife photographers, and ecotourists travel to these shores to view and study these splendid creatures. Petersburg, being a major fishing port, enjoys a large fleet of commercial vessels as well as a small charter fleet that provides viewing opportunities. With so much already here: the environment, the sea life, the research community, and the public, it became only natural for Petersburg Marine Mammal Center to arise and provide a link to the community, students, and visitors.
Several beautiful fjords, bays and glaciers adorn Frederick Sound. One of the most famous of these is LeConte Glacier, which is the southern-most tidewater glacier in the Northern Hemisphere. It produces a vast amount of calving icebergs which can sometimes be viewed flowing out of the fjord on the eastern end of the Sound. These icebergs are the reason the Norwegian fishermen founded Petersburg—a fishing port on Mitkof Island. They collected the ice to pack and send their fish south down the Western seaboard toward San Francisco.