Beluga whale swimming with calf. Credit: Chris Garner, Joint Base Elmendorf–Richardson.
Beluga whale swimming with calf. Credit: Chris Garner, Joint Base Elmendorf–Richardson.
About the Species
Beluga whales are known for their white color and range of vocal sounds, earning them the title of "canary of the sea." They are very social animals, forming groups to hunt, migrate, and interact with each other.
Beluga whales are found globally throughout the Arctic and sub-Arctic waters, in the United States, in the state of Alaska. They are at home along coastal bays and inlets and can move between salt and freshwater. A thick layer of fat, called blubber, and thick skin helps them live in the freezing waters of the arctic and subarctic environment. Belugas also lack a dorsal fin so that they can swim with ice.
Beluga whales are vulnerable to many stressors and threats, including pollution, habitat degradation, harassment, interactions with commercial and recreational fisheries, oil and gas exploration, disease, predation from killer whales, and other types of human disturbance.
Commercial and sport hunting once threatened beluga whale populations. These activities are now banned, though some Alaska Natives still hunt beluga whales for subsistence—the practice of hunting marine mammals for food, clothing, and handicrafts are necessary for preserving the livelihood of Native communities. In 2005, a harvest management plan was approved to regulate the Cook Inlet beluga harvest. Alaska Native hunters last harvested Cook Inlet beluga whales in 2005.
All beluga whale populations are protected under the Marine Mammal Protection Act (MMPA). NOAA Fisheries has designated the Cook Inlet beluga whale population in Alaska and the Sakhalin Bay-Nikolaya Bay-Amur River stock in Russia as depleted under the MMPA (i.e., they have fallen below their optimum sustainable population levels).
In addition, the Cook Inlet distinct population segment has been listed as an endangered species under the Endangered Species Act. Cook Inlet belugas are one of NOAA Fisheries' Species in the Spotlight—an initiative that includes animals considered most at risk for extinction and prioritizes their recovery efforts.
NOAA Fisheries is committed to conserving beluga whales. Our scientists and partners use a variety of innovative techniques to study and protect beluga whales.
and protecting and rebuilding depleted and endangered populations. We also work with our partners to protect critical habitat for Cook Inlet belugas and engage the public in conservation efforts.
Population Status
In the United States, NOAA Fisheries identified five stocks of beluga whales in Alaskan waters. The five stocks of beluga whales are:
- Beaufort Sea
- Bristol Bay
- Cook Inlet
- Eastern Bering Sea
- Eastern Chukchi Sea
Each stock is unique, isolated from one another genetically and geographically by migration routes and preferred habitats. NOAA Fisheries' stock assessment reports estimate population size for marine mammal stocks within U.S. waters.
Worldwide, belugas may number in the hundreds of thousands; however, some stocks are small, numbering in the low hundreds. The endangered Cook Inlet beluga whale population has declined by nearly 80 percent since 1979, from about 1,300 whales to an estimated 279 whales in 2018. The rapid decline and dire status of the Cook Inlet beluga whale population makes it a priority for NOAA Fisheries and its partners to promote recovery to prevent extinction.
The population of Sakhalin Bay-Nikolaya Bay-Amur River beluga whales, a stock in the eastern North Pacific off the coast of Russia, is estimated to be around 3,961 whales. In response to a petition, NOAA Fisheries conducted a status review of the stock and designated it as depleted under the MMPA in 2016.
Protected Status
ESA Endangered
1 distinct population segment
CITES Appendix II
MMPA Protected
MMPA Depleted
1 stock
MMPA Depleted
1 stock
- Sakhalin Bay-Nikolaya Bay-Amur River stock
Appearance
Beluga whales are dark grey as calves. Their skin lightens as they age, becoming white as they reach physical maturity. They lack a pronounced rostrum, or beak, and the top of their head is characterized by a round, flexible “melon” that focuses and modulates their vocalizations, including echolocation “clicks.” They are a toothed whale, possessing 18 to 20 teeth in both the upper and lower jawbones, for a total of 36 to 40 teeth.
The genus name Delphinapterus translates to “dolphin without a fin.” Instead of a dorsal fin, belugas have a tough dorsal ridge, which allows them to swim easily under ice floes (sheets of floating ice). Unlike other whales and dolphins, their neck vertebrae are not fused, so belugas can nod and move their heads from side to side.
Beluga whales are covered with a thick layer of blubber that accounts for up to 40 percent of their weight. The blubber keeps them warm in the arctic waters and stores energy. Some beluga populations shed their outer layer of skin each summer during an annual molt. They rub against coarse gravel in shallow waters to help remove the layer of old, yellowed skin.
Behavior and Diet
Belugas are social animals. They return to their birth areas each summer to feed and calve. Groups may range from one or two whales to several hundred whales. Individuals move between groups within these populations, unlike some killer whales, which appear to have strong ties within their maternal-led pods.
Belugas are known as the "canaries of the sea" because they produce many different sounds, including whistles, squeals, moos, chirps, and clicks. They rely on their hearing and ability to echolocate, using sound to navigate and hunt for prey. Belugas also have sharp vision in and out of water.
Beluga whales have a varied diet consisting of octopus, squid, crabs, shrimp, clams, snails, and sandworms. They also eat a variety of fish, including salmon, eulachon, cod, herring, smelt, and flatfish.
Where They Live
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 1,000-meter depths for periods of up to 25 minutes. They swim among ice floes in arctic and subarctic waters, where temperatures may be as low as 32°F. 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 habitats.
World map providing approximate representation of the beluga whale's range.
Lifespan & Reproduction
Similar to tree rings that can be used to age a tree, beluga teeth acquire a “growth layer group” (GLG) for each year they age. The oldest beluga on record had 80 GLGs, though this may be an underestimate of the whale’s true age due to the wear on their teeth. The oldest Cook Inlet beluga whale had 49 GLGs.
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.
Threats
Beluga whale populations are exposed to a variety of stressors and threats, including pollution (e.g., chemicals, trash), shipping, energy exploration and development, commercial fishing, extreme weather events, strandings, predation from killer whales and polar bears, underwater noise, subsistence harvesting, and other types of human disturbance. The Cook Inlet population has additional threats because of its proximity to the most densely populated area of Alaska (Anchorage).
Habitat Degradation
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
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. Because contaminants have long lifespans and blubber stores, belugas accumulate these contaminants in their bodies, threatening their immune and reproductive systems.
Prey Limitations
Overfishing, habitat changes, development, and the impacts of climate change can decrease the amount of food available to beluga whales. Without enough prey, belugas might experience decreased reproductive rates and increased mortality rates. Understanding the potential for food limitations to hinder population recovery is especially important for Cook Inlet beluga whales because they live in an area with high human activity.
Strandings
Live strandings occur when marine mammals become "beached" or stuck in shallow water. The exact cause of most stranding cases is unknown. Belugas may strand when molting avoiding predators; or avoiding other threats, such as noise and vessel traffic; when chasing prey, or when suffering from injuries or disease. Unlike other whales and dolphins, healthy belugas that live-strand wait for the high tide to refloat and swim to deeper water. Unfortunately, belugas have died after live strandings. Belugas with compromised immune systems may not survive a live stranding through a tide cycle.
Ocean Noise
Underwater noise pollution interrupts the normal behavior of beluga whales, which rely on sound to communicate and echolocate. If loud enough, noise can cause permanent or temporary hearing loss. This is of particular concern for the Cook Inlet population, which inhabits an area with high vessel traffic, oil and gas exploration and development, dredging and pile-driving, airports, military operations, and other noise-making anthropogenic (human-caused) activities.
Climate Change
The impacts of climate change on whales are unknown, but it is considered one of the largest threats facing high latitude regions where many gray whales forage. Most notably, the timing and distribution of sea ice coverage is changing dramatically with altered oceanographic conditions. Any resulting changes in prey distribution could lead to changes in foraging behavior, nutritional stress, and diminished reproduction for beluga whales. Additionally, changing water temperature and currents could impact the timing of environmental cues important for navigation and migration.
Scientific Classification
| Animalia |
Chordata |
Mammalia |
Cetacea |
Monodontidae |
Delphinapterus |
leucas |
