. . . Predicting and Minimizing Environmental Impacts . . .
 

The Species



Harbor Porpoise (Phocoena phocoena)


© 2002 Encyclopædia Britannica, Inc.

Any toothed whale in the family Phocoenidae. The four species (genus Phocoena) of the common, or harbour, porpoise are primarily fish eaters that travel in pairs or large groups. They are gray or black above and white below. The shy P. phocoena, found throughout the Northern Hemisphere, rarely leaps. The other species of Phocoena are found along Californian and South American coasts. The active, gregarious Dall porpoise (Phocoenoides dalli) of the North Pacific and the True porpoise (P. truei) of Japan often swim with ships, usually in groups of 2 to 20. Both eat cephalopods and fishes and are black with a large white patch on each side. The black finless porpoise (Neomeris phocoenoides), a small, slow animal, inhabits the Pacific and Indian oceans. At most 7 ft (2 m) long, porpoises are shorter and chubbier than dolphins and have a blunt snout.

For an in-depth description, visit the harbor porpoise species profile at OBIS-SEAMAP.



Harbor Seal (Phoca vitulina)

Nonmigratory, earless seal found throughout the Northern Hemisphere. Harbour seals are whitish or grayish at birth, generally gray with black spots as adults. The adult male may reach a length of about 6 ft (1.8 m) and a weight of almost 300 lb (130 kg); the female is somewhat smaller. Found along coastlines and in a few freshwater lakes in Canada and Alaska, the harbour seal is a gregarious animal that feeds on fish, squid, and crustaceans. It is of little economic value and in some areas is considered a nuisance by fishermen.

For an in-depth description, visit the harbor seal species profile at OBIS-SEAMAP.



Humpback Whale (Megaptera novaeangliae)


© 2002 Encyclopædia Britannica, Inc.

They live along all major ocean coasts, sometimes swimming close inshore or even into harbours and up rivers. Humpbacks grow to 40–52 ft (12–16 m) long. They are black above, with some white below, and have large knobs on the head and jaws. The humpback migrates between polar waters in summer and tropical or subtropical breeding grounds in winter. It feeds on shrimplike crustaceans, small fish, and plankton. It is probably the most vocal of all whales and one of the most acrobatic. Much reduced in number by overhunting, humpbacks have been protected worldwide since the 1960s, and some populations seem to be increasing.

For an in-depth description, visit the humpback whale species profile at OBIS-SEAMAP.



Leatherback Sea Turtle (Dermochelys coriacea)


© 2002 Encyclopædia Britannica, Inc.

The leatherback is the largest, deepest diving, and most migratory and wide ranging of all sea turtles. The adult leatherback can reach 4 to 8 feet in length and 500 to 2000 pounds in weight. Its shell is composed of a mosaic of small bones covered by firm, rubbery skin with seven longitudinal ridges or keels. The skin is predominantly black with varying degrees of pale spotting; including a notable pink spot on the dorsal surface of the head in adults. A toothlike cusp is located on each side of the gray upper jaw; the lower jaw is hooked anteriorly. The paddle-like clawless limbs are black with white margins and pale spotting. Hatchlings are predominantly black with white flipper margins and keels on the carapace. Jellyfish are the main staple of its diet, but it is also known to feed on sea urchins, squid, crustaceans, tunicates, fish, blue-green algae, and floating seaweed.

For an in-depth description, visit the leatherback species profile at OBIS-SEAMAP.



N. Atlantic Right Whale (Eubalaena glacialis)


© 2002 Encyclopædia Britannica, Inc.

Any of five species (genera Balaena, Eubalaena, and Caperea) of baleen whales (family Balaenidae) with a stout body and an enormous head. The upper jaw is strongly arched, and the lower lip curves upward along the side, giving the lower jaw a scooplike form. There is no dorsal fin except in the pygmy right whale (Caperea marginata), a small, seldom-seen whale of the Southern Hemisphere. The bowhead whale (Balaena mysticetus), inhabiting Arctic and northern temperate waters, is black, with a white chin, throat, and sometimes underparts. It grows to about 65 ft (20 m). The northern right whale (E. glacialis) grows to 60 ft (18 m). Similar to the bowhead but with a smaller, less strongly arched head, it may also have a “bonnet,” a horny growth infested with parasites, on its snout. Both species have been protected since 1946.

For an in-depth description, visit the right whale species profile at OBIS-SEAMAP.



Sperm Whale (Physeter macrocephalus)


© 2002 Encyclopædia Britannica, Inc.

Sperm whales have an enormous head, squarish in profile, and a narrow, underslung lower jaw with large conical teeth that fit into sockets in the toothless upper jaw when the mouth is closed. They are dark blue-gray or brownish. (Herman Melville's Moby-Dick was presumably an albino.) The male grows to 60 ft (18 m). Herds of 15–20 live in temperate and tropical waters worldwide. They commonly dive to 1,200 ft (350 m), feeding primarily on cephalopods. The whales have been hunted for their spermaceti (a waxy substance in the snout, used in ointments and cosmetics) and for ambergris.

For an in-depth description, visit the sperm whale species profile at OBIS-SEAMAP.