They also eat a variety of fish, including salmon, eulachon, cod, herring, smelt, and flatfish. Beluga whales live in the Arctic Ocean and its nearby seas in the Northern Hemisphere. They are common to many regions of Alaska, as well as Russia, Canada, and Greenland.
Belugas are usually found in shallow coastal waters during the summer months, often in shallow water. During other seasons, they may be found in deeper waters, diving to 1,meter depths for periods of up to 25 minutes. Belugas also seasonally inhabit estuaries and large river deltas to feed on fish runs, and are thus well-adapted to both cold ocean habitats and relatively warmer freshwater habitat. Beluga whales are believed to mate in late winter and spring.
Depending on the population, this may occur during migration or in their wintering grounds. Females reach sexual maturity when they are about 6 to 14 years old, and males when they are slightly older. Pregnancy lasts approximately 15 months, and calves nurse for at least 2 years. Females can give birth every 2 to 3 years. Pregnancy rates showed signs of decline after age 46 years old in northwest Alaska.
It is notable, however, that the oldest female in the northwest Alaska sample, at age 70, was carrying a near-term fetus. The oldest female beluga whale from Cook Inlet was 47 years old and appeared to have recently given birth. Belugas generally give birth during summer in areas where the water is relatively warm, as newborn calves lack a thick blubber layer to protect them from cold water.
Calves benefit from the warmer waters found in shallow tidal flats and estuaries. Beluga whale populations are exposed to a variety of stressors and threats, including pollution e. The Cook Inlet population has additional threats because of its proximity to the most densely populated area of Alaska Anchorage. Beluga whales are susceptible to habitat destruction and degradation.
This can range from barriers that limit their access to important migration, breeding, feeding, and calving areas, to activities that destroy or degrade their habitats.
Barriers that could prevent beluga movements may include shoreline and offshore development oil and gas exploration and development, harbors and ports, dredging, pile driving and increased boat traffic. Contaminant releases may also degrade habitat.
Contaminants enter ocean waters from many sources, including point source and nonpoint source, such as oil and gas development, wastewater discharges, urban runoff, and other industrial processes. Once in the environment, these substances move up the food chain and accumulate in predators at the top of the food chain such as beluga whales.
T he discovery of a beluga whale in Norwegian waters that may or may not be working for the Russian navy has captured worldwide attention.
The find alarmed Norwegian officials and led to speculation that the mammal may have been trained to spy for Russia. The Russian defense ministry has denied having a program that uses marine mammals, the Guardian reported. If the whale is indeed a Russian spy, as speculated in headlines around the world, it would not be the first marine mammal drafted into military service.
In the s, at the height of the Cold War, the Soviet authorities reportedly trained beluga wales, dolphins, sea lions and fur seals to search for underwater mines and other objects.
Following the collapse of the Soviet Union, marine mammal training was discontinued and, according to a BBC report, the guard dolphins were sold to Iran.
In , after the Russian annexation of Crimea, the dolphins came under the control of the Russian Ministry of Defense. Having survived her long journey, first overland to New York and then by ship across the Atlantic Ocean, the beluga only lived for four days at the aquarium. Perhaps she died from stress or exhaustion. Maybe her internal organs and muscles were damaged, since whales are not built to withstand the pressure of their heavy bodies on a flat surface for a long time.
It is unlikely that the beluga died from being placed in fresh water, because belugas often make their way up rivers, far from the sea and salt water, and do just fine. The aquarium staff that examined the animal after it died, including a naturalist named Henry Lee, found pneumonia in her lungs, likely from the trip across the Atlantic.
The men in charge of her care did not understand at the time that whales have difficulty managing their own body heat when out of water. With her thick layer of blubber, the beluga might have actually been too hot.
In telling the story of this whale, Henry Lee wrote about belugas, which were the first whales that aquariums regularly displayed in the United States and in Great Britain, even before they displayed dolphins. First observed by the Inuit of the Arctic, and then later by European explorers, whalers, and fishermen, beluga whales do have some of the most varied vocalizations of any marine mammals. From their blowholes, they make a range of sounds that include moos, whistles, tweets, and a wet brambling sound that is an awful lot like a flatulent toot.
With echolocation through their oil-filled melons, belugas send out an even greater variety of clicks, squeaks, and rattles, some of which are too high-pitched for humans to hear. Lawrence, Canada. See How do marine mammals communicate using sound? Originating in the air sacs of the head, these vocalizations sound like a variety of whistles , squeals, chirps and clicks.
It is even possible to hear these sounds above water or through the hull the main body of a ship or vessel most of which goes under the water , including the bottom, sides, and deck but not the masts, superstructure, rigging, engines, and other fittings. Belugas emit non-echolocation calls with an average frequency range from 2. Additionally, a captive beluga produced echolocation sounds between 40 and 60 kHz in one location and between and kHz after it was transported to another location.
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