The narwhal, or narwhale, Monodon monoceros, Occurs casually in Alaska waters, is a medium-sized toothed whale that lives year-round in the Arctic. One of two living species of whale in the Monodontidae family, along with the beluga whale, narwhal males are distinguished by a long, straight, helical tusk, actually an elongated upper left canine. Found primarily in Canadian Arctic and Greenlandic waters, rarely south of 65°N latitude, the narwhal is a uniquely specialized Arctic predator. In the winter, it feeds on benthic prey, mostly flatfish, at depths of up to 1500 m under dense pack ice. Narwhals have been harvested for over a thousand years by Inuit people in northern Canada and Greenland for meat and ivory, and a regulated subsistence hunt continues to this day. While populations appear stable, the narwhal is particularly vulnerable to climate change due to a narrow geographical range and specialized diet.
The sperm whale (Physeter macrocephalus) is a large toothed whale (odontocete) belonging to the order Cetacea. It is the only living member of genus Physeter, and one of three extant species in the sperm whale family, along with the pygmy sperm whale and dwarf sperm whale of the genus Kogia. A marine mammal, it possesses the largest brain of any animal. Its name derives from a milky-white waxy substance, spermaceti, found in its enormous head.
A mature male can grow to 67 ft long, its head representing up to one-third of the animal's length. The largest living toothed animal, the species feeds primarily on giant and colossal squid. Plunging to 3 kilometres (9,800 ft) for prey, it is the deepest diving mammal. Its clicking vocalization, a form of sonar which may have other purposes, is the loudest sound produced by any animal.
Cuvier's beaked whale (Ziphius cavirostris) is the most widely distributed of all the beaked whales. It is the only member of the genus Ziphius. Another common name for the species is goose-beaked whale because its head is said to be shaped like the beak of a goose.
Stejneger's beaked whale (Mesoplodon stejnegeri), sometimes known as the Bering Sea beaked whale or the Saber-toothed whale, is a poorly-known member of the genus Mesoplodon inhabiting the northern North Pacific Ocean. Leonhard Hess Stejneger collected the type specimen (a beach-worn skull) on Bering Island in 1883, which provided the description by Frederick W. True in 1885. In 1904, the first complete skull (from an adult male that had stranded near Newport, Oregon) was collected, which confirmed the species' validity. The most noteworthy characteristic of the males is the very large, saber-like teeth, hence the name.
Risso's have a relatively large anterior body and dorsal fin, while the posterior tapers to a relatively narrow tail. The bulbous head has a vertical crease in front.
Infants are dorsally gray to brown and ventrally cream-colored, with a white anchor-shaped area between the pectorals and around the mouth. In older calves, the non-white areas darken to nearly black, and then lighten (except for the always dark dorsal fin.) Linear scars mostly from social interaction eventually cover the bulk of the body. Older individuals appear mostly white. Most individuals have 2–7 pairs of teeth, all in the lower jaw.
Length is typically 10 feet although specimens may reach 14.1 feet. Like most dolphins, males are typically slightly larger than females. This species weighs 660–1,100 lb making it the largest species called "dolphin".
The Killer whale is also known as the orca whale because it has been known to attack and eat other whales, and large prey animals such as seals and sea lions. Orcas are scattered among the Continental Shelf from southeast Alaska through the Aleutian Islands. They can also be seen in the waters of Prince William Sound.
The harbour porpoise (Phocoena phocoena) is one of six species of porpoise. It is one of the smallest marine mammals. As its name implies, it stays close to coastal areas or river estuaries, and as such, is the most familiar porpoise to whale watchers. This porpoise often ventures up rivers, and has been seen hundreds of miles from the sea. The harbour porpoise may be polytypic, with geographically distinct populations representing distinct races: P. p. phocoena in the North Atlantic and West Africa, P. p. relicta in the Black Sea and Sea of Azov, an unnamed population in the northwest Pacific and P. p. vomerina in the northeast Pacific.
The unique body shape of Dall's porpoise makes it easily distinguishable from other cetacean species. The animal has a very thick body and a small head. The colouration is rather like that of a killer whale; the main body of the porpoise is very dark grey to black creeper, with very demarcated white patches on the flank and belly. The dorsal fin is set just back from the middle of the back and sits up erect. The upper part of the dorsal fin has a white to light grey "frosting".
The fluke has a similar frosting. The adult fluke curves back towards the body of the animal, which is another distinguishing feature. It is larger than other porpoises, growing up to 7.5 ft in length and weighing between 290 and 490 lb. There is also sexual dimorphism in the species, with males being larger, having a deeper caudal peduncle and a pronounced hump behind the anus. Young Dall's have a greyish tint and dark-colored flukes.
During the summer, belugas eat a variety of fish, occasionally supplemented by other small marine life. Belugas' winter feeding habits are virtually unknown. Belugas are generally found in the ocean, but they may also ascend large rivers such as the Yukon on occasion and do not appear to be affected by the salinity change. There are two populations of belugas in Alaska. The Cook Inlet population is found in the inlet and Shelikof Strait region, and numbers approximately 400 to 500 animals. The larger Bering Sea population ranges throughout the Bering, Chukchi, and Beaufort seas; this group comprises perhaps 25,000 animals. Alaska natives harvest small numbers of belugas for food and oil.
The Bering Sea stock of bowhead whales is the species' only population that exists in significant numbers, due to previous commercial whaling. While there were 18,000 Bering Sea bowheads before the introduction of commercial whaling, as of 1992[update] their population was only between 6,400 and 9,200. Bering Sea bowheads follow a 3,600-mile (5800 km) migration route, wintering in the Bering Sea, then moving through the Bering Strait, across the Chuckchi Sea, and into the Canadian Beaufort Sea for the summer. To Alaskan Inuit, bowhead whales are the most important subsistence animal, both culturally and nutritionally. Subsistence whale hunts are managed in accordance with the International Whaling Commission; 41 whales were taken in 1993.
Blue whales, which can be found in all the world's oceans, are rare north of the Bering Sea. Blue whales, which are migratory, may be seen in Alaska during the summer; historically, they have been sighted in the eastern Gulf of Alaska, the eastern Aleutians, and the far western Aleutians. Blue whales are rarely seen in near-shore Alaska waters, preferring to spend time along the edges of continental shelves. There have been few recent sightings of blue whales in Alaska; the total north Pacific population of blue whales was approximately 1,200 to 1,700 as of 1994, down from 4,900 to 6,000 before the advent of whaling. In the north Pacific, blue whales primarily eat the krill species Euphausia pacifica and Thysanoessa spinifera.