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. 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 both in the water and on the many rocky islets throughout the viewing area. A variety of sea birds are also present.
Frederick Sound west of Portage Bay, lower Stephens Passage, and the confluence of Frederick Sound with Chatham Strait (See map). The center of this area is approximately 45 miles, by water, northwest of Petersburg, Alaska.