Beluga
Encyclopedia
The beluga or white whale, Delphinapterus leucas, is an Arctic
and sub-Arctic cetacean. It is one of two members of the family Monodontidae
, along with the narwhal
. This marine mammal
is commonly referred to simply as the beluga or sea canary due to its high-pitched twitter. It is up to 5 metres (16.4 ft) in length and an unmistakable all-white color with a distinctive protuberance on the head. From a conservation perspective, the beluga is considered "near threatened" by the International Union for Conservation of Nature; however the subpopulation from the Cook Inlet
in Alaska
is considered critically endangered and is under the protection of the United States' Endangered Species Act
. Of seven Canadian beluga populations, two are listed as endangered, inhabiting eastern Hudson Bay, and Ungava Bay.
first described the beluga. It is a member of the Monodontidae
family
, which is in turn part of the toothed whale
suborder. The Irrawaddy dolphin
was once placed in the same family; however, recent genetic evidence suggests otherwise. The narwhal
is the only other species within the Monodontidae besides the beluga.
The Red List of Threatened Species gives both beluga and white whale as common names, though the former is now more popular. The English name comes from the Russian
белуха (belukha), which derives from the word белый (belyy), meaning "white". It is sometimes referred to by scientists as the belukha whale to avoid confusion with the beluga sturgeon
.
The whale is also colloquially known as the sea canary on account of its high-pitched squeaks, squeals, clucks and whistles. A Japanese researcher says he taught a beluga to "talk" by using these sounds to identify three different objects, offering hope that humans may one day be able to communicate effectively with sea mammals.
Male belugas are larger than females. Length can range from 2.6 to 6.7 m (8.5 to 22 ft), averaging 4 m (13.1 ft) in males and 3.6 m (11.8 ft) in females. Males weigh between 1100 and 1600 kg (2,425.1 and 3,527.4 lb), occasionally up to 1900 kg (4,188.8 lb) while females weigh between 700 and 1200 kg (1,543.2 and 2,645.5 lb). They rank as mid-sized species among toothed whales.
The adult beluga is rarely mistaken for another species, because it is completely white or whitish-gray in color. Calves, however, are usually gray. Its head is unlike that of any other cetacean. Like most toothed whales it has a melon
—an oily, fatty tissue lump found at the center of the forehead. The beluga's melon is extremely bulbous and even malleable. The beluga is able to change the shape of its head by blowing air around its sinuses. Unlike many dolphins and whales, the vertebrae in the neck are not fused together, allowing the animal to turn its head laterally. The rostrum
has about 8 to 10 teeth on each side of the jaw and a total of 34 to 40 teeth.
Belugas have a dorsal ridge, rather than a dorsal fin
. The absence of the dorsal fin is reflected in the genus name of the species—apterus the Greek
word for "wingless." The evolutionary preference for a dorsal ridge rather than a fin is believed to be an adaptation to under-ice conditions, or possibly as a way of preserving heat. As in other cetaceans, the thyroid
gland is relatively large compared to terrestrial
mammals (proportionally three times as large as a horse's thyroid) and may help to sustain higher metabolism during the summer estuarine
occupations.
Its body is round, particularly when well-fed, and tapers less smoothly to the head than the tail. The sudden tapering to the base of its neck gives it the appearance of shoulders, unique among cetaceans. The tail fin grows and becomes increasingly and ornately curved as the animal ages. The flippers are broad and short—making them almost square-shaped.
The beluga inhabits a discontinuous circumpolar distribution in Arctic and sub-Arctic waters ranging from 50° N to 80° N, particularly along the coasts of Alaska
, Canada
, Greenland
, and Russia
. The southernmost extent of their range includes isolated populations in the St. Lawrence River estuary and the Saguenay fjord
, around the village of Tadoussac, Quebec
, in the Atlantic and the Amur River delta, the Shantar Islands
and the waters surrounding Sakhalin Island in the Sea of Okhotsk
.
In the spring, the beluga moves to its summer grounds: bay
s, estuaries
and other shallow inlets. These summer sites are discontinuous. A mother usually returns to the same site year after year. As its summer homes clog with ice during autumn, the beluga moves away for winter. Most travel in the direction of the advancing icepack and stay close to its edge for the winter months. Others stay under the icepack—surviving by finding ice leads and polynya
s (patches of open water in the ice) in which they can surface to breathe. Beluga may also find air pockets trapped under the ice. The beluga's ability to find the thin slivers of open water within a dense ice pack that may cover more than 96% of the surface mystifies scientists. Its echo-location
capabilities are highly adapted to the sub-ice sea's peculiar acoustics and it has been suggested that belugas can sense open water through echo-location.
In 1849, while constructing the first railroad between Rutland and Burlington
in Vermont
, workers unearthed the bones of a mysterious animal in the town of Charlotte
. Buried nearly 10 feet (3 m) below the surface in a thick blue clay
, these bones were unlike those of any animal previously discovered in Vermont. Experts identified the bones as those of a beluga. Because Charlotte is over 150 miles (241.4 km) from the nearest ocean, early naturalists were at a loss to explain the bones of a marine mammal
buried beneath the fields of rural Vermont. Today, the Charlotte whale aids in the study of the geology and the history of the Champlain Basin, and this fossil is now the official Vermont State Fossil (making Vermont the only state whose official fossil is that of a still extant animal).
On June 9, 2006, a young beluga carcass was found in the Tanana River
near Fairbanks
in central Alaska, nearly 1700 kilometres (1,056.3 mi) from the nearest ocean habitat. Belugas sometimes follow migrating fish, leading Alaska state biologist Tom Seaton to speculate that it had followed migrating salmon
up the river at some point in the prior fall.
Belugas are highly sociable. Groups of males may number in the hundreds, while mothers with calves generally mix in slightly smaller groups. When pods aggregate in estuaries, they may number in the thousands. This can represent a significant proportion of the entire population and is when they are most vulnerable to hunting.
Pods tend to be unstable, meaning that they tend to move from pod to pod. Radio tracking has shown that belugas can start out in a pod and within a few days be hundreds of miles away from that pod. Mothers and calves form the beluga's closest social relationship. Nursing times of two years have been observed and lactational anestrus may not occur. Calves often return to the same estuary as their mother in the summer, meeting her sometimes even after becoming fully mature.
Belugas can be playful—they may spit at humans or other whales. It is not unusual for an aquarium
handler to be drenched by one of his charges. Some researchers believe that spitting originated with blowing sand away from crustacean
s at the sea bottom.
Unlike most whales, it is capable of swimming backwards.
Males reach sexual maturity between four and seven years, while females mature at between six and nine years. The beluga can live more than 50 years.
Female belugas typically give birth to one calf every three years. Most mating occurs between February and May, but some mating occurs at other times of year. It is questionable whether the beluga has delayed implantation
. Gestation lasts 12 to 14.5 months.
Calves are born over a protracted period that varies by location. In the Canadian Arctic, calves are born between March and September, while in Hudson Bay
, the peak calving period is in late June, and in Cumberland Sound
, most calves are born from late July to early August.
Newborns are about 1.5 metres (4.9 ft) long, weigh about 80 kilograms (176.4 lb), and are grey in color. The calves remain dependent on their mothers for at least two years.
. It also eats cephalopod
s (squid
and octopus
) and crustaceans (crab
and shrimp
). Foraging on the seabed typically takes place at depths of up to 1000 feet (304.8 m) but they can dive at least twice this depth. A typical feeding dive lasts 3–5 minutes, but belugas submerge for up to 20 minutes at a time.
is its other significant natural predator.
in New York City
in 1861. Today it remains one of the few whale species kept at aquaria
and sea life parks across North America, Europe, and Asia. Its popularity there with visitors reflects its attractive color, and its range of facial expressions. While most cetacean "smiles" are fixed, the extra movement afforded by the beluga's unfused cervical vertebrae allows a greater range of apparent expression. Most belugas found in aquaria are caught in the wild, though captive breeding programs enjoy some success.
Both the United States Navy
and the Russian Navy have used belugas in anti-mining
operations in Arctic waters. In one instance, a captive beluga brought a cramp-paralyzed diver from the bottom of the pool up to the surface by holding her foot in its mouth, certainly saving the female diver's life.
The global population of belugas today stands at about 100,000. Although this number is much greater than that of many other cetaceans, it is much smaller than pre-hunting populations. There are estimated to be 40,000 individuals in the Beaufort Sea
, 25,045 in Hudson Bay
, 18,500 in the Bering Sea
, and 28,008 in the Canadian Low Arctic. The population in the St. Lawrence estuary
is estimated to be around 1,000. It is considered an excellent sentinel species (indicator of environment health and changes). This is because it is long-lived, on top of the food web, bearing large amounts of fat and blubber, relatively well-studied for a cetacean, and still somewhat common.
Because the beluga congregates in river estuaries, pollution is proving to be a significant health danger. Incidents of cancer
have been reported to be rising as a result of St. Lawrence River pollution. Local beluga carcasses contain so many contaminants that they are treated as toxic waste. Reproductive pathology has been discovered here, possibly caused by organochlorines
. Levels between 240 ppm and 800 ppm of PCB
s have been found, with males typically having higher levels. The long-term effects of this pollution on the affected populations is not known.
Indirect human disturbance may also be a threat. While some populations tolerate small boats, others actively try to avoid ships. Whale-watching has become a booming activity in the St. Lawrence and Churchill River
areas.
Because of its predictable migration pattern and high concentrations, the beluga has been hunted by indigenous Arctic peoples for centuries. In many areas, hunting continues, and is believed to be sustainable. However, in other areas, such as the Cook Inlet
, Ungava Bay
, and off western Greenland
, previous commercial operations left the populations in great peril. Indigenous whaling continues in these areas, and some populations continue to decline. These areas are the subject of intensive dialogue between Inuit
communities and national governments aiming to create a sustainable hunt.
es have been found in the gastric compartments of belugas in the St. Lawerence River. Herpesvirus as well has been detected on occasion in belugas. Encephalitis
has sometimes been observed and the protozoa
Sarcocystis
can infect the animals. Ciliates have been observed to colonize the blowhole yet may not be pathogen
ic or especially harmful.
Erysipelothrix rhusiopathiae
bacilli
, likely from contaminated fish in the diet, can endanger captive belugas, causing anorexia
, dermal plaques, and lesion
s. This may lead to death if not diagnosed early and treated with antibiotics.
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As of 2008, the beluga is listed as "near threatened" by the IUCN, due to uncertainty about the number of belugas over parts of its range (especially the Russian Arctic), and the expectation that if current conservation efforts cease, especially hunting management, the beluga population is likely to qualify for "threatened" status within five years. Prior to 2008, the beluga was listed as "vulnerable", a higher level of concern. IUCN cited the stability of the largest subpopulations and improved census methods that indicate a larger population than previously estimated.
To prevent hunting, belugas are protected under the International Moratorium on Commercial Whaling; however, small amounts of beluga whaling are still allowed. Since it is very difficult to know the exact population of belugas because their habitats include inland waters away from the ocean, it is easy for them to come in contact with oil
and gas
development centers. To prevent whales from coming in contact with industrial waste, the Alaskan and Canadian governments are relocating sites where whales and waste come in contact.
To prevent captive whales from dying, researchers from the Vancouver Aquarium Marine Science Centre are finding ways to prevent fungi from entering the habitats and to constantly check their health. Healthy captive belugas are important because they are one of the only whales found in many marine aquariums. The high numbers of captives adds to the threat to the beluga population, while their carcasses contribute to scientific research.
Subpopulations are subject to differing levels of threat and warrant individual assessment. The Cook Inlet subpopulation is listed as "Critically Endangered" by the IUCN as of 2006. The Cook Inlet beluga population is listed as Endangered under the Endangered Species Act
as of October 2008.
This was due to overharvesting of belugas prior to 1998. The population has failed to recover even though the reported harvest has been small. The most recent published estimate as of May 2008 was 302 (CV=0.16) in 2006. In addition, the National Marine Fisheries Service
indicated the 2007 aerial survey's point estimate was 375.
The Beluga whale is listed on appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). It is listed on Appendix II as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.
from the late Miocene
period. A single fossil from the Baja California peninsula
, indicates that the family once inhabited warmer waters. The fossil record also indicates that in comparatively recent times the beluga's range varied with that of the polar ice packs—expanding during ice age
s and contracting when the ice retreats.
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...
and sub-Arctic cetacean. It is one of two members of the family Monodontidae
Monodontidae
The cetacean family Monodontidae comprises two unusual whale species, the narwhal, in which the male has a long tusk, and the white beluga whale...
, along with the narwhal
Narwhal
The narwhal, Monodon monoceros, 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, the narwhal males are distinguished by a characteristic long, straight, helical tusk extending from their...
. This marine mammal
Marine mammal
Marine mammals, which include seals, whales, dolphins, and walruses, form a diverse group of 128 species that rely on the ocean for their existence. They do not represent a distinct biological grouping, but rather are unified by their reliance on the marine environment for feeding. The level of...
is commonly referred to simply as the beluga or sea canary due to its high-pitched twitter. It is up to 5 metres (16.4 ft) in length and an unmistakable all-white color with a distinctive protuberance on the head. From a conservation perspective, the beluga is considered "near threatened" by the International Union for Conservation of Nature; however the subpopulation from the Cook Inlet
Cook Inlet
Cook Inlet stretches from the Gulf of Alaska to Anchorage in south-central Alaska. Cook Inlet branches into the Knik Arm and Turnagain Arm at its northern end, almost surrounding Anchorage....
in Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
is considered critically endangered and is under the protection of the United States' Endangered Species Act
Endangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...
. Of seven Canadian beluga populations, two are listed as endangered, inhabiting eastern Hudson Bay, and Ungava Bay.
Taxonomy
In 1776, Peter Simon PallasPeter Simon Pallas
Peter Simon Pallas was a German zoologist and botanist who worked in Russia.- Life and work :Pallas was born in Berlin, the son of Professor of Surgery Simon Pallas. He studied with private tutors and took an interest in natural history, later attending the University of Halle and the University...
first described the beluga. It is a member of the Monodontidae
Monodontidae
The cetacean family Monodontidae comprises two unusual whale species, the narwhal, in which the male has a long tusk, and the white beluga whale...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, which is in turn part of the toothed whale
Toothed whale
The toothed whales form a suborder of the cetaceans, including sperm whales, beaked whales, dolphins, and others. As the name suggests, the suborder is characterized by the presence of teeth rather than the baleen of other whales.-Anatomy:Toothed whales have a single blowhole on the top of the head...
suborder. The Irrawaddy dolphin
Irrawaddy dolphin
The Irrawaddy dolphin is a euryhaline species of oceanic dolphin found in discontinuous subpopulations near sea coasts and in estuaries and rivers in parts of the Bay of Bengal and Southeast Asia.-Etymology and taxonomic history:...
was once placed in the same family; however, recent genetic evidence suggests otherwise. The narwhal
Narwhal
The narwhal, Monodon monoceros, 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, the narwhal males are distinguished by a characteristic long, straight, helical tusk extending from their...
is the only other species within the Monodontidae besides the beluga.
The Red List of Threatened Species gives both beluga and white whale as common names, though the former is now more popular. The English name comes from the Russian
Russian language
Russian is a Slavic language used primarily in Russia, Belarus, Uzbekistan, Kazakhstan, Tajikistan and Kyrgyzstan. It is an unofficial but widely spoken language in Ukraine, Moldova, Latvia, Turkmenistan and Estonia and, to a lesser extent, the other countries that were once constituent republics...
белуха (belukha), which derives from the word белый (belyy), meaning "white". It is sometimes referred to by scientists as the belukha whale to avoid confusion with the beluga sturgeon
Beluga sturgeon
The beluga or European sturgeon is a species of anadromous fish in the sturgeon family of order Acipenseriformes. It is found primarily in the Caspian and Black Sea basins, and occasionally in the Adriatic Sea...
.
The whale is also colloquially known as the sea canary on account of its high-pitched squeaks, squeals, clucks and whistles. A Japanese researcher says he taught a beluga to "talk" by using these sounds to identify three different objects, offering hope that humans may one day be able to communicate effectively with sea mammals.
Description
The adult beluga is rarely mistaken for another species, because it is completely white or whitish-gray in color. Calves, however, are usually gray. Its head is unlike that of any other cetacean. Like most toothed whales it has a melon
Melon (whale)
The melon is an ovoid-shaped, fatty organ found in the forehead of all toothed whales , including dolphins and porpoises and believed to be used in echolocation....
—an oily, fatty tissue lump found at the center of the forehead. The beluga's melon is extremely bulbous and even malleable. The beluga is able to change the shape of its head by blowing air around its sinuses. Unlike many dolphins and whales, the vertebrae in the neck are not fused together, allowing the animal to turn its head laterally. The rostrum
Rostrum (anatomy)
The term rostrum is used for a number of unrelated structures in different groups of animals:*In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes....
has about 8 to 10 teeth on each side of the jaw and a total of 34 to 40 teeth.
Belugas have a dorsal ridge, rather than a dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
. The absence of the dorsal fin is reflected in the genus name of the species—apterus the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
word for "wingless." The evolutionary preference for a dorsal ridge rather than a fin is believed to be an adaptation to under-ice conditions, or possibly as a way of preserving heat. As in other cetaceans, the thyroid
Thyroid
The thyroid gland or simply, the thyroid , in vertebrate anatomy, is one of the largest endocrine glands. The thyroid gland is found in the neck, below the thyroid cartilage...
gland is relatively large compared to terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
mammals (proportionally three times as large as a horse's thyroid) and may help to sustain higher metabolism during the summer estuarine
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
occupations.
Its body is round, particularly when well-fed, and tapers less smoothly to the head than the tail. The sudden tapering to the base of its neck gives it the appearance of shoulders, unique among cetaceans. The tail fin grows and becomes increasingly and ornately curved as the animal ages. The flippers are broad and short—making them almost square-shaped.
Range and habitat
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
, and Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
. The southernmost extent of their range includes isolated populations in the St. Lawrence River estuary and the Saguenay fjord
Saguenay River
The Saguenay River is a major river of Quebec, Canada.It drains Lac Saint-Jean in the Laurentian Highlands, leaving at Alma and running east, and passes the city of Saguenay. It drains into the Saint Lawrence River at Tadoussac....
, around the village of Tadoussac, Quebec
Tadoussac, Quebec
Tadoussac is a village in Quebec, Canada, at the confluence of the Saint Lawrence and Saguenay rivers. It was France's first trading post on the mainland of New France and an important trading post in the seventeenth century, making it the oldest continuously inhabited European settlement in...
, in the Atlantic and the Amur River delta, the Shantar Islands
Shantar Islands
The Shantar Islands are a group of fifteen islands that lie in Uda Bay, in the southwestern zone of the Sea of Okhotsk. These islands are located close to the shores of the Siberian mainland...
and the waters surrounding Sakhalin Island in the Sea of Okhotsk
Sea of Okhotsk
The Sea of Okhotsk is a marginal sea of the western Pacific Ocean, lying between the Kamchatka Peninsula on the east, the Kuril Islands on the southeast, the island of Hokkaidō to the far south, the island of Sakhalin along the west, and a long stretch of eastern Siberian coast along the west and...
.
In the spring, the beluga moves to its summer grounds: bay
Bay
A bay is an area of water mostly surrounded by land. Bays generally have calmer waters than the surrounding sea, due to the surrounding land blocking some waves and often reducing winds. Bays also exist as an inlet in a lake or pond. A large bay may be called a gulf, a sea, a sound, or a bight...
s, estuaries
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
and other shallow inlets. These summer sites are discontinuous. A mother usually returns to the same site year after year. As its summer homes clog with ice during autumn, the beluga moves away for winter. Most travel in the direction of the advancing icepack and stay close to its edge for the winter months. Others stay under the icepack—surviving by finding ice leads and polynya
Polynya
A polynya or polynia is an area of open water surrounded by sea ice. It is now used as geographical term for an area of unfrozen sea within the ice pack. It is a loanword from , , which means a natural ice hole, and was adopted in the 19th century by polar explorers to describe navigable...
s (patches of open water in the ice) in which they can surface to breathe. Beluga may also find air pockets trapped under the ice. The beluga's ability to find the thin slivers of open water within a dense ice pack that may cover more than 96% of the surface mystifies scientists. Its echo-location
Animal echolocation
Echolocation, also called biosonar, is the biological sonar used by several kinds of animals.Echolocating animals emit calls out to the environment and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects...
capabilities are highly adapted to the sub-ice sea's peculiar acoustics and it has been suggested that belugas can sense open water through echo-location.
In 1849, while constructing the first railroad between Rutland and Burlington
Burlington, Vermont
Burlington is the largest city in the U.S. state of Vermont and the shire town of Chittenden County. Burlington lies south of the U.S.-Canadian border and some south of Montreal....
in Vermont
Vermont
Vermont is a state in the New England region of the northeastern United States of America. The state ranks 43rd in land area, , and 45th in total area. Its population according to the 2010 census, 630,337, is the second smallest in the country, larger only than Wyoming. It is the only New England...
, workers unearthed the bones of a mysterious animal in the town of Charlotte
Charlotte, Vermont
Charlotte is a town in Chittenden County, Vermont, United States. The town was named for Sofia Charlotte of Mecklenburg-Strelitz, youngest daughter of Duke Charles Louis Frederick of Mecklenburg-Strelitz.The population was 3,569 at the 2000 census....
. Buried nearly 10 feet (3 m) below the surface in a thick blue clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...
, these bones were unlike those of any animal previously discovered in Vermont. Experts identified the bones as those of a beluga. Because Charlotte is over 150 miles (241.4 km) from the nearest ocean, early naturalists were at a loss to explain the bones of a marine mammal
Marine mammal
Marine mammals, which include seals, whales, dolphins, and walruses, form a diverse group of 128 species that rely on the ocean for their existence. They do not represent a distinct biological grouping, but rather are unified by their reliance on the marine environment for feeding. The level of...
buried beneath the fields of rural Vermont. Today, the Charlotte whale aids in the study of the geology and the history of the Champlain Basin, and this fossil is now the official Vermont State Fossil (making Vermont the only state whose official fossil is that of a still extant animal).
On June 9, 2006, a young beluga carcass was found in the Tanana River
Tanana River
The Tanana River is a tributary of the Yukon River in the U.S. state of Alaska. According to linguist and anthropologist William Bright, the name is from the Koyukon tene no, tenene, literally "trail river"....
near Fairbanks
Fairbanks, Alaska
Fairbanks is a home rule city in and the borough seat of the Fairbanks North Star Borough in the U.S. state of Alaska.Fairbanks is the largest city in the Interior region of Alaska, and second largest in the state behind Anchorage...
in central Alaska, nearly 1700 kilometres (1,056.3 mi) from the nearest ocean habitat. Belugas sometimes follow migrating fish, leading Alaska state biologist Tom Seaton to speculate that it had followed migrating salmon
Salmon
Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...
up the river at some point in the prior fall.
Life history
Pods tend to be unstable, meaning that they tend to move from pod to pod. Radio tracking has shown that belugas can start out in a pod and within a few days be hundreds of miles away from that pod. Mothers and calves form the beluga's closest social relationship. Nursing times of two years have been observed and lactational anestrus may not occur. Calves often return to the same estuary as their mother in the summer, meeting her sometimes even after becoming fully mature.
Belugas can be playful—they may spit at humans or other whales. It is not unusual for an aquarium
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
handler to be drenched by one of his charges. Some researchers believe that spitting originated with blowing sand away from crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s at the sea bottom.
Unlike most whales, it is capable of swimming backwards.
Males reach sexual maturity between four and seven years, while females mature at between six and nine years. The beluga can live more than 50 years.
Reproduction
Embryonic diapause
Delayed Implantation or Embryonic Diapause is a reproductive strategy used by approximately 100 different mammals in seven or eight different orders. In embryonic diapause, the embryo does not immediately implant in the uterus, but is maintained in a state of dormancy. Little to no development...
. Gestation lasts 12 to 14.5 months.
Calves are born over a protracted period that varies by location. In the Canadian Arctic, calves are born between March and September, while in Hudson Bay
Hudson Bay
Hudson Bay , sometimes called Hudson's Bay, is a large body of saltwater in northeastern Canada. It drains a very large area, about , that includes parts of Ontario, Quebec, Saskatchewan, Alberta, most of Manitoba, southeastern Nunavut, as well as parts of North Dakota, South Dakota, Minnesota,...
, the peak calving period is in late June, and in Cumberland Sound
Cumberland Sound
Cumberland Sound is an Arctic waterway in Qikiqtaaluk Region, Nunavut, Canada. It is a western arm of the Labrador Sea located between Baffin Island's Hall Peninsula and the Cumberland Peninsula...
, most calves are born from late July to early August.
Newborns are about 1.5 metres (4.9 ft) long, weigh about 80 kilograms (176.4 lb), and are grey in color. The calves remain dependent on their mothers for at least two years.
Feeding
The beluga is a slow swimmer that feeds mainly on fishFish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
. It also eats cephalopod
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
s (squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
and octopus
Octopus
The octopus is a cephalopod mollusc of the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms...
) and crustaceans (crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
and shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
). Foraging on the seabed typically takes place at depths of up to 1000 feet (304.8 m) but they can dive at least twice this depth. A typical feeding dive lasts 3–5 minutes, but belugas submerge for up to 20 minutes at a time.
Predation
Polar bears take particular advantage of situations when belugas become trapped by ice and are thus unable to reach the ocean. The bears swipe at the belugas and drag them onto the ice. The orcaOrca
The killer whale , commonly referred to as the orca, and less commonly as the blackfish, is a toothed whale belonging to the oceanic dolphin family. Killer whales are found in all oceans, from the frigid Arctic and Antarctic regions to tropical seas...
is its other significant natural predator.
Relation to humans
Belugas were among the first whale species in captivity. The first beluga was shown at Barnum's MuseumBarnum's American Museum
Barnum's American Museum was located at the corner of Broadway and Ann Street in New York City, USA, from 1841 to 1865. The museum was owned by famous showman P.T. Barnum and his partner and original owner, John Scudder. Prior to their partnership, the museum was known as Scudder's American...
in New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
in 1861. Today it remains one of the few whale species kept at aquaria
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
and sea life parks across North America, Europe, and Asia. Its popularity there with visitors reflects its attractive color, and its range of facial expressions. While most cetacean "smiles" are fixed, the extra movement afforded by the beluga's unfused cervical vertebrae allows a greater range of apparent expression. Most belugas found in aquaria are caught in the wild, though captive breeding programs enjoy some success.
Both the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
and the Russian Navy have used belugas in anti-mining
Naval mine
A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...
operations in Arctic waters. In one instance, a captive beluga brought a cramp-paralyzed diver from the bottom of the pool up to the surface by holding her foot in its mouth, certainly saving the female diver's life.
Population and threats
Beaufort Sea
The Beaufort Sea is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, the Yukon, and Alaska, west of Canada's Arctic islands. The sea is named after hydrographer Sir Francis Beaufort...
, 25,045 in Hudson Bay
Hudson Bay
Hudson Bay , sometimes called Hudson's Bay, is a large body of saltwater in northeastern Canada. It drains a very large area, about , that includes parts of Ontario, Quebec, Saskatchewan, Alberta, most of Manitoba, southeastern Nunavut, as well as parts of North Dakota, South Dakota, Minnesota,...
, 18,500 in the Bering Sea
Bering Sea
The Bering Sea is a marginal sea of the Pacific Ocean. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves....
, and 28,008 in the Canadian Low Arctic. The population in the St. Lawrence estuary
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
is estimated to be around 1,000. It is considered an excellent sentinel species (indicator of environment health and changes). This is because it is long-lived, on top of the food web, bearing large amounts of fat and blubber, relatively well-studied for a cetacean, and still somewhat common.
Because the beluga congregates in river estuaries, pollution is proving to be a significant health danger. Incidents of cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
have been reported to be rising as a result of St. Lawrence River pollution. Local beluga carcasses contain so many contaminants that they are treated as toxic waste. Reproductive pathology has been discovered here, possibly caused by organochlorines
Organochloride
An organochloride, organochlorine, chlorocarbon, chlorinated hydrocarbon, or chlorinated solvent is an organic compound containing at least one covalently bonded chlorine atom. Their wide structural variety and divergent chemical properties lead to a broad range of applications...
. Levels between 240 ppm and 800 ppm of PCB
Polychlorinated biphenyl
Polychlorinated biphenyls are a class of organic compounds with 2 to 10 chlorine atoms attached to biphenyl, which is a molecule composed of two benzene rings. The chemical formula for PCBs is C12H10-xClx...
s have been found, with males typically having higher levels. The long-term effects of this pollution on the affected populations is not known.
Indirect human disturbance may also be a threat. While some populations tolerate small boats, others actively try to avoid ships. Whale-watching has become a booming activity in the St. Lawrence and Churchill River
Churchill River (Hudson Bay)
The Churchill River is a major river in Alberta, Saskatchewan and Manitoba, Canada. From the head of the Churchill Lake it is 1,609 km long. It was named after John Churchill, 1st Duke of Marlborough and governor of the Hudson's Bay Company from 1685 to 1691...
areas.
Because of its predictable migration pattern and high concentrations, the beluga has been hunted by indigenous Arctic peoples for centuries. In many areas, hunting continues, and is believed to be sustainable. However, in other areas, such as the Cook Inlet
Cook Inlet
Cook Inlet stretches from the Gulf of Alaska to Anchorage in south-central Alaska. Cook Inlet branches into the Knik Arm and Turnagain Arm at its northern end, almost surrounding Anchorage....
, Ungava Bay
Ungava Bay
Ungava Bay is a large bay in northeastern Canada separating Nunavik from Baffin Island. The bay is shaped like a rounded square with a side length of about and has an area of approximately...
, and off western Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
, previous commercial operations left the populations in great peril. Indigenous whaling continues in these areas, and some populations continue to decline. These areas are the subject of intensive dialogue between Inuit
Inuit
The Inuit are a group of culturally similar indigenous peoples inhabiting the Arctic regions of Canada , Denmark , Russia and the United States . Inuit means “the people” in the Inuktitut language...
communities and national governments aiming to create a sustainable hunt.
Pathogens
PapillomavirusPapillomavirus
Papillomaviridae is an ancient taxonomic family of non-enveloped DNA viruses, collectively known as papillomaviruses. Several hundred species of papillomaviruses, traditionally referred to as "types", have been identified infecting all carefully inspected birds and mammals, but also a small number...
es have been found in the gastric compartments of belugas in the St. Lawerence River. Herpesvirus as well has been detected on occasion in belugas. Encephalitis
Encephalitis
Encephalitis is an acute inflammation of the brain. Encephalitis with meningitis is known as meningoencephalitis. Symptoms include headache, fever, confusion, drowsiness, and fatigue...
has sometimes been observed and the protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
Sarcocystis
Sarcocystis
Sarcocystis is a genus of protozoa. Species in this genus infect reptiles, birds and mammals. The name is dervived from Greek: sarx = flesh and kystis = bladder.There are about 130 recognised species in this genus...
can infect the animals. Ciliates have been observed to colonize the blowhole yet may not be pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
ic or especially harmful.
Erysipelothrix rhusiopathiae
Erysipelothrix rhusiopathiae
Erysipelothrix rhusiopathiae is a gram-positive, catalase-negative, rod-shaped bacterium. It grows aerobically and anaerobically and does not contain endotoxin. Distributed worldwide, E. rhusiopathiae is primarily considered an animal pathogen, causing a disease known as erysipelas in animals...
bacilli
Bacilli
Bacilli refers to a taxonomic class of bacteria. It includes two orders, Bacillales and Lactobacillales, which contain several well-known pathogens like Bacillus anthracis .-Ambiguity:...
, likely from contaminated fish in the diet, can endanger captive belugas, causing anorexia
Anorexia (symptom)
Anorexia is the decreased sensation of appetite...
, dermal plaques, and lesion
Lesion
A lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :...
s. This may lead to death if not diagnosed early and treated with antibiotics.
Conservation status
To prevent hunting, belugas are protected under the International Moratorium on Commercial Whaling; however, small amounts of beluga whaling are still allowed. Since it is very difficult to know the exact population of belugas because their habitats include inland waters away from the ocean, it is easy for them to come in contact with oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
and gas
Gas
Gas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
development centers. To prevent whales from coming in contact with industrial waste, the Alaskan and Canadian governments are relocating sites where whales and waste come in contact.
To prevent captive whales from dying, researchers from the Vancouver Aquarium Marine Science Centre are finding ways to prevent fungi from entering the habitats and to constantly check their health. Healthy captive belugas are important because they are one of the only whales found in many marine aquariums. The high numbers of captives adds to the threat to the beluga population, while their carcasses contribute to scientific research.
Subpopulations are subject to differing levels of threat and warrant individual assessment. The Cook Inlet subpopulation is listed as "Critically Endangered" by the IUCN as of 2006. The Cook Inlet beluga population is listed as Endangered under the Endangered Species Act
Endangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...
as of October 2008.
This was due to overharvesting of belugas prior to 1998. The population has failed to recover even though the reported harvest has been small. The most recent published estimate as of May 2008 was 302 (CV=0.16) in 2006. In addition, the National Marine Fisheries Service
National Marine Fisheries Service
The National Marine Fisheries Service is a United States federal agency. A division of the National Oceanic and Atmospheric Administration and the Department of Commerce, NMFS is responsible for the stewardship and management of the nation's living marine resources and their habitat within the...
indicated the 2007 aerial survey's point estimate was 375.
The Beluga whale is listed on appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). It is listed on Appendix II as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.
Evolution
The beluga's earliest known ancestor is the prehistoric Denebola brachycephalaDenebola brachycephala
Denebola brachycephala is an extinct whale belonging to the family Monodontidae. It is the first known ancestor of the beluga and dates from the Upper Miocene period. A fossil was found in the Baja California peninsula, indicating that the family once existed in warmer waters....
from the late Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
period. A single fossil from the Baja California peninsula
Baja California Peninsula
The Baja California peninsula , is a peninsula in northwestern Mexico. Its land mass separates the Pacific Ocean from the Gulf of California. The Peninsula extends from Mexicali, Baja California in the north to Cabo San Lucas, Baja California Sur in the south.The total area of the Baja California...
, indicates that the family once inhabited warmer waters. The fossil record also indicates that in comparatively recent times the beluga's range varied with that of the polar ice packs—expanding during ice age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
s and contracting when the ice retreats.
See also
- Pour la suite du mondePour la suite du mondePour la suite du monde is a 1963 Canadian documentary film directed by Michel Brault and Pierre Perrault. It was entered into the 1963 Cannes Film Festival....
, a documentary about traditional beluga hunting on the Saint Lawrence River
Further reading
}}- Outridge, P. M., K. A. Hobson, R. McNeely, and A. Dyke. 2002. "A Comparison of Modern and Preindustrial Levels of Mercury in the Teeth of Beluga in the Mackenzie Delta, Northwest Territories, and Walrus at Igloolik, Nunavut, Canada". Arctic. 55: 123–132.
External links
- US National Marine Fisheries Service beluga whale page
- Cook Inlet Beluga Population Info
- Vancouver Aquarium Beluga Webcam
- ARkive Photos
- Animal Diversity Web
- Video of belugas blowing bubble rings and performing other tricks at a Japanese aquarium
- Convention on Migratory Species page on the Beluga / White whale