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Belugas are extremely sociable mammals that live, hunt and migrate together in pods, ranging from a few individuals to hundreds of whales. Their bulbous forehead, called a 'melon”, is flexible and capable of changing shape. This allows them to make different facial expressions. Belugas can produce a series of chirps, clicks, whistles and squeals, which give the beluga its other name, 'the canary of the sea.' They may sound like music or even nonsense to us, but to fellow belugas they convey important information.
Many populations of belugas migrate as the sea ice changes in the Arctic. They move south in the fall as the ice forms and then return to feed again in the spring, as the ice breaks up. They can also be found near river mouths, and sometimes even venture up river. Belugas feed on a variety of fish species, such as salmon and herring, as well as shrimp, crabs and mollusks.
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This predominantly Arctic species is associated with ice floes. Its movement patterns are therefore influenced by the melting and freezing of the ice.
Bowhead whales are capable of breaking through sea ice at least seven inches thick with their large skulls and powerful bodies.
Adult bowheads are entirely black except the front part of the lower jaw which is white and prominently upturned. They can grow up to 60 feet long while still being able to leap entirely out of water. Bowheads filter their food through baleen by opening their mouths and straining plankton from the surface, the water column, or the sea floor.
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Dolphin, any of the toothed whales belonging to the mammal family Delphinidae (oceanic dolphins) as well as the families Platanistidae and Iniidae, the two that contain the river dolphins. Of the nearly 40 species of dolphins in the Delphinidae, 6 are commonly called whales, including the killer whale and the pilot whales. The name dolphin is also applied to members of the fish genus Coryphaena (family Coryphaenidae). Most dolphins are small, measuring less than 3 metres (10 feet) in length, and have spindle-shaped bodies, beaklike snouts (rostrums), and simple needlelike teeth. Some of these cetaceans are occasionally called porpoises, but scientists prefer to use this term as the common name for the six species in the family Phocoenidae, all of which differ from dolphins in having blunt snouts and spadelike teeth. Dolphins are popularly noted for their grace, intelligence, playfulness, and friendliness to humans. The most widely recognized species are the common and bottlenose dolphins (Delphinus delphis and Tursiops truncatus, respectively). The bottlenose, characterized by a “built-in smile” formed by the curvature of its mouth, has become a familiar performer in oceanariums. It has also become the subject of scientific studies because of its intelligence and ability to communicate by using a range of sounds and ultrasonic pulses. It adapts to captivity better than the common dolphin, which is timid.
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The harp seal is a true seal that lives in the north Atlantic and Arctic Oceans, spending long periods of time associated with sea ice. This species gets its common name from the harp-shaped markings on the back of the otherwise darkly colored adults. Young pups are solid white. This species is highly migratory, with individuals following Arctic sea ice as it expands and contracts throughout the year.
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Most seals are at home in frigid waters, but the Hawaiian monk seal is a rare tropical exception. Hawaiian monk seals live in the remote Northwestern Hawaiian Islands. These small islands and atolls are either uninhabited or little-used by humans. They are also surrounded with teeming coral reefs, which serve as great foraging grounds for skilled seals to swim and dive for fish, spiny lobsters, octopuses, and eels.
Monk seals spend most of their time at sea, but they come ashore to rest on beaches and use fringe vegetation as shelter from storms.
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Hooded seal, (Cystophora cristata), also called bladdernose seal, large grayish seal with dark spots that is found in open waters of the North Atlantic and Arctic oceans. Hooded seals range from the Svalbard archipelago and the Barents Sea to the Gulf of St. Lawrence. Average-sized adult males measure about 2.6 metres (8.5 feet) long and typically weigh between 300 and 400 kg (660 and 880 pounds), whereas average-sized females measure 2.2 metres (7 feet) and weigh between 160 and 230 kg (350 and 500 pounds). Hooded seals are named for the nasal ornamentation occurring in sexually mature males. Hanging like a wrinkled sac when relaxed, the appendage can be inflated to become a hood that covers the front of the face and the top of the head. Adult males also have an elastic nasal septum that can be inflated to become a reddish balloon in front of their face
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Marine Otters are the smallest species of otter in the genus Lontra. They have a body length between 50 and 79 cms (20 - 31 inches), a tail length between 30 and 36 cms (12 - 14 inches) and they weigh between 3 and 5 kgs (6.6 - 11 lbs). Marine Otters are found exclusively in marine habitats along the Pacific coast of South America, from northern Peru, along the coast of Chile, to the southern tip of South America. Marine Otters breed once a year and after a gestation period of 60 - 65 days, 2 - 4 youngsters are born. The youngsters remain with their parents until they reach independence at 10 months old.
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The minke whale is the smallest baleen whale in North American waters. These rorquals have a relatively small, dark, sleek body that can reach lengths of up to about 35 feet and weigh up to 20,000 pounds. Females may be slightly larger than males. Minke whales have a fairly tall, sickle-shaped dorsal fin located about two-thirds down their back. Their body is black to dark grayish/brownish, with a pale chevron on the back behind the head and above the flippers, as well as a white underside. Calves are usually darker in coloration than adults.Minke whales are usually sighted individually or in small groups of two to three, but loose groupings of up to 400 animals have been seen in feeding areas closer to the poles. The segregation and distribution of these Northern Hemisphere whales suggests a complex social and population structure, but less is known about the populations in the Southern Hemisphere.
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The narwhal is the unicorn of the sea, a pale-colored porpoise found in Arctic coastal waters and rivers. These legendary animals have two teeth. In males, the more prominent tooth grows into a swordlike, spiral tusk up to 10 feet long. The ivory tusk tooth grows right through the narwhal's upper lip. Scientists are not certain of the tusk's purpose, but some believe it is prominent in mating rituals, perhaps used to impress females or to battle rival suitors. Females sometimes grow a small tusk of their own, but it does not become as prominent as the male's.
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The playful North American river otter is equally at home in the water and on land. It makes its home in a burrow near the water's edge, and can thrive in river, lake, swamp, or estuary ecosystems. Otter abodes feature numerous tunnels—one of which usually allows them to come and go from the water.
Males do not help raise young otters. Females retreat to their underground dens to deliver litters of one to six young. When the young are only about two months old, they get an advanced swimming lesson—their mother pushes them into the water. Otters are natural swimmers and, with parental supervision, they soon get the hang of it.
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The killer whale, also known as orca, is one of the top marine predators. It is the largest member of the Delphinidae family, or oceanic dolphins. Members of this family include all dolphin species, as well as other larger species such as the long-finned pilot whales and short-finned pilot whales, whose common names also contain 'whale' instead of 'dolphin.' Killer whales are mostly black on top with white undersides and white patches near the eyes. They also have a gray or white saddle patch behind the dorsal fin. These markings vary widely between individuals and populations. Adult males develop disproportionately larger pectoral flippers, dorsal fins, tail flukes, and girths than females.
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Risso's dolphins, sometimes called gray dolphins, are found in the temperate and tropical zones of all the world’s oceans. These cetaceans generally prefers deeper offshore waters, especially near the continental shelf edge and slope, where they can dive to at least 1,000 feet and hold their breath for 30 minutes. They are also very active on the ocean surface.Risso's dolphins have a robust body with a narrow tailstock. These medium-sized cetaceans can reach lengths of approximately 8.5 to 13 feet and weigh 660 to 1,100 pounds. Males and females are usually about the same size. They have a bulbous head with a vertical crease and an indistinguishable beak. They have a tall, curved, sickle-shaped dorsal fin located mid-way down their back.
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California sea lions are “eared seals” native to the West Coast of North America. They live in coastal waters and on beaches, docks, buoys, and jetties. They are easily trained and intelligent and are commonly seen in zoos and aquariums. California sea lions are playful, intelligent, and very vocal (sounding like barking dogs). Adult females and juveniles are slender-bodied and are blonde to tan in color. Adult males are generally larger than females and are mostly dark brown to black in color. Pups are dark brown at birth and weigh about 16 pounds. When pups are 4 to 5 months old, they molt their dark brown coats for light brown or silver coats.
California sea lions have broad front flippers and long, narrow snouts. Subadult and adult males have pronounced forehead crests crowned with tufts of blonde or lighter hair. California sea lions have visible ear flaps, and three to five claws on their hind flippers.
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The rare Southern river otter lives in freshwater systems with abundant riparian vegetation. It hunts mainly fish, but also forages for crabs, molluscs and birds. It is found in inland lakes and close to the rocky coastal habitats of Argentina and Chile, never far from a source of freshwater. The Southern river otter’s habitat is very fragmented, possibly due to its rarity and also the fact that this extremely shy animal avoids the many fishing villages and areas with no potential shelter. Imported salmon is taking over some areas, and by devouring local fish species and being too fast for otters to catch, its presence is proving to be a problem for the Southern River otter.
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Sperm whales are easily recognized by their massive heads and prominent rounded foreheads.
They have the largest brain of any creature known to have lived on Earth. Their heads also hold large quantities of a substance called spermaceti. Whalers once believed that the oily fluid was sperm, but scientists still do not understand the function of spermaceti. One common theory is that the fluid—which hardens to wax when cold—helps the whale alter its buoyancy so it can dive deep and rise again. Sperm whales are known to dive as deep as 3,280 feet in search of squid to eat. These giant mammals must hold their breath for up to 90 minutes on such dives.
These toothed whales eat thousands of pounds of fish and squid—about one ton per day. Sperm whales are often spotted in groups (called pods) of some 15 to 20 animals. Pods include females and their young, while males may roam solo or move from group to group. Females and calves remain in tropical or subtropical waters all year long, and apparently practice communal childcare. Males migrate to higher latitudes, alone or in groups, and head back towards the equator to breed. Driven by their tale fluke, approximately 16 feet from tip to tip, they can cruise the oceans at around 23 miles per hour.
These popular leviathans are vocal and emit a series of “clangs” that may be used for communication or for echolocation. Animals that use echolocation emit sounds that travel underwater until they encounter objects, then bounce back to their senders—revealing the location, size, and shape of their target.
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The Spotted-necked otter is so-called because of the creamy white mottled blotches on the neck and chest. Its long sinuous body is covered in dense, water-repellent fur, and its color ranges from reddish to chocolate brown. More aquatic than other otters from Africa, its fully webbed paws have sharp, well-developed claws. Inside its short, broad muzzle are relatively small teeth, which are adapted for catching fish instead of the crustaceans that the clawless otters eat. Its long hairy tail ends in a point and is flattened horizontally.
Spotted-necked otters are carnivores, they eat mainly fish, but also eat frogs, mollusks, crabs, and aquatic insects and their larvae. Typically solitary, the Spotted-necked otter lives in a small family group, according to the time of year. Sometimes they forage in loosely knit groups with up to 20 individuals. They may do this because it is easier to catch fish if they keep the shoal together. Males have a large home range with more than one female living within it. It has one or more dens (or holts) in its territory, one of the entrances typically being underwater. Although this species is usually crepuscular or nocturnal, the otters in Lake Victoria are diurnal. These animals may be vocal, with a range of calls including a contact call, which is a harsh mewing, and a high pitched distress call which is a squawking. They enjoy playing, either with other otters or alone.
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Subantarctic fur seals are uniquely colored amongst otariids; their dark brown or gray dorsal surface contrasts with a pale ventral surface. They are strongly sexually dimorphic with adult males some three times heavier than adult females. Subantarctic fur seals breed on seven island groups in the Southern Ocean, north of the Antarctic Polar Front. Some 99% of pup production takes place at Gough Island, the Prince Edward Islands, and Amsterdam Island. Adults haul out in the austral summer to breed in polygynous aggregations. Following this, adult females undertake regular foraging trips typically of several hundred kilometers each until their pups are weaned at 10 months of age. Prey is primarily myctophid fish and cephalopods. Although this species was reduced to low numbers by commercial sealing by the early 20th century, the population has since grown to some 400,000 and its conservation designation is Least Concern.
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Vaquita, the world's rarest marine mammal, is on the edge of extinction. The plight of cetaceans—whales, dolphins, and porpoises—as a whole is exemplified by the rapid decline of the vaquita in Mexico, with about 10 individuals remaining. This little porpoise wasn't discovered until 1958 and a little over half a century later, we are on the brink of losing them forever. Vaquita are often caught and drowned in gillnets used by illegal fishing operations in marine protected areas within Mexico's Gulf of California. The population has dropped drastically in the last few years.
The vaquita has a large dark ring around its eyes and dark patches on its lips that form a thin line from the mouth to the pectoral fins. Its top—the dorsal surface—is dark gray, its sides are pale gray, and its underside—the ventral surface—is white with long, light gray markings. Newborn vaquita have darker coloration and a wide gray fringe of color that runs from the head to the flukes, passing through the dorsal and pectoral fins. They are most often found close to shore in the Gulf's shallow waters, although they quickly swim away if a boat approaches.
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The mustached and long-tusked walrus is most often found near the Arctic Circle, lying on the ice with hundreds of companions. These marine mammals are extremely sociable, prone to loudly bellowing and snorting at one another, but are aggressive during mating season. With wrinkled brown and pink hides, walruses are distinguished by their long white tusks, grizzly whiskers, flat flipper, and bodies full of blubber. The two subspecies of walrus are divided geographically. Atlantic walruses inhabit coastal areas from northeastern Canada to Greenland, while Pacific walruses inhabit the northern seas off Russia and Alaska, migrating seasonally from their southern range in the Bering Sea—where they are found on the pack ice in winter—to the Chukchi Sea. Female Pacific walruses give birth to calves during the spring migration north.
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