Beluga whale swimming with calf. Photo: Chris Garner, Joint Base Elmendorf–Richardson
Beluga whale swimming with calf. Photo: 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 in the United States in Alaska and globally throughout the Arctic Ocean. They are at home in large rivers and can move between salt and fresh water. 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 under ice.
Beluga whales are vulnerable to many stressors and threats, including pollution, habitat degradation, predation from killer whales, harassment, interactions with commercial and recreational fisheries, oil and gas exploration, disease, and other types of human disturbance such as underwater noise.
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, shelter, heating, and other uses necessary for preserving the livelihood of Native communities. Beluga subsistence harvest in the Cook Inlet of south-central Alaska is now regulated because of the lack of recovery in the area. Alaska Natives last hunted Cook Inlet beluga whales in 2005.
All beluga whale populations are protected under the Marine Mammal Protection Act. NOAA Fisheries has designated the Cook Inlet beluga whale population in Alaska and the Sakhalin Bay-Nikolaya Bay-Amur River stock off the coast of 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 and protecting and rebuilding depleted and endangered populations. Our scientists and partners use a variety of innovative techniques to study and protect beluga whales. We also work with our partners to protect critical habitat for Cook Inlet belugas and engage the public in conservation efforts.
Status
In the United States, NOAA Fisheries has identified five stocks of beluga whales, all in Alaskan waters—the Beaufort Sea, Bristol Bay, Cook Inlet, eastern Bering Sea, and eastern Chukchi Sea stocks. Each stock is unique, isolated from one another genetically and/or physically by migration routes and preferred habitats. NOAA Fisheries' stock assessment reports estimate population size for 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 prevent extinction and promote recovery.
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
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 sexual 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 36 to 40 teeth total in both the upper and lower jawbones.
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 hunt, breed, and calve. Groups may range from one or two whales to several hundred. Individuals move between groups within these populations, unlike 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 both 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 fishes, including salmon, cod, sole, herring, eulachon, smelt, and flounder.
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 water barely deep enough to cover their bodies. 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 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. The oldest Cook Inlet beluga whale had 49 GLGs.
Beluga whales are believed to mate in late winter and early spring. Depending on the population, this may occur during migration or in their wintering grounds. Females reach sexual maturity when they are about 9 to 14 years old, and males when they are slightly older. Pregnancy lasts ~15 months, and calves nurse for 2 years. Females give birth every 2 to 3 years.
Pregnancy rates showed signs of decline after age 40 in the eastern Chukchi Sea females and at around 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 water of shallow tidal flats and estuaries.
Threats
Beluga whale populations are exposed to a variety of stressors and threats, including pollution (e.g., heavy metals, chemicals, trash), shipping, energy exploration, commercial fishing, extreme weather events, strandings, predation from killer whales, subsistence harvesting, and other types of human disturbance such as underwater noise. The Cook Inlet population faces additional threats because of its proximity to the most densely populated area of Alaska (Anchorage) during the summer season.
Habitat Degradation
Beluga whales are susceptible to habitat destruction and degradation. This can range from physical barriers that limit their access to important migration, breeding, feeding, or calving areas, to activities that destroy or degrade their habitats. Physical barriers may include shoreline and offshore development (oil and gas exploration, dredging, pile driving) and increased boat traffic. Contaminant releases may also degrade habitat.
Contaminants
Contaminants enter ocean waters from many sources, including 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 of their long lifespan and blubber stores, belugas accumulate these contaminants in their bodies, threatening their immune and reproductive systems.
Food Limitations
Overfishing, habitat changes, and the impacts of climate change can decrease the amount of food available to beluga whales. Without enough prey, they 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 cause of most stranding cases is unknown. Belugas may strand when molting (to avoid predation or 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 are usually able to refloat and swim to deeper water during the next high tide. Unfortunately, belugas have died after stranding on their sides and inhaling muddy water. Larger belugas with compromised immune systems also may not survive stranding through a tidal 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, military operations, and other noise-making anthropogenic (human-caused) activities.
Scientific Classification
| Animalia |
Chordata |
Mammalia |
Cetacea |
Monodontidae |
Delphinapterus |
leucas |
