Beluga Whale (Delphinapterus leucas)

Beluga Whale
(Delphinapterus leucas)
Photo: NMFS National Marine Mammal Laboratory

Did You Know?

· Belugas are known as the "canaries of the sea" because of the vast range of sounds they produce .

· The name beluga comes from the Russian word "bielo" for white.

· Belugas have flexible necks, allowing them to move their heads separate from their bodies.

Status
ESA Endangered - Cook Inlet
MMPA Depleted - Cook Inlet

Taxonomy
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Monodontidae
Genus: Delphinapterus
Species: leucas

Species Description
The beluga whale (Delphinapterus leucas) is a small, white-toothed whale. Adult belugas may reach a length of 16 feet (5 m), though average size is 12 to 14 ft (about 4 m). Males may weigh about 3,300 lbs (1,500 kg) and females 3,000 lbs (1,360 kg). Beluga whales lack a dorsal fin and do not typically produce a visible "blow" when breathing at the surface.

Unlike other cetaceans, belugas can move their head up, down, and side to side, because their cervical vertebrae are not fused. This feature appears to be an adaptation to maneuvering and catching prey in muddy or ice-covered areas.

Beluga whales are covered with a thick layer of blubber that accounts for as much as 40 percent of their body mass. This fat provides thermal protection and stores energy. Belugas are unique among cetaceans in that they shed their outer layer of skin, or molt, each summer around July. They concentrate in shallow water where there is coarse gravel to rub against. The rubbing action helps remove the top layer of old yellow skin and reveal the new skin underneath.

Beluga whales mate in the spring, usually in March or April, in small bays and estuaries. Gestation lasts about 14-15 months, and calves are born between March and September, mostly between May and July. Females give birth to single calves (and on rare occasion twins) every two to three years on average. They give birth where the water is relatively warm (50-60° F or 10-15° C). Beluga calves nurse for at least 12 to 18 months, until their teeth emerge, at which point they supplement their diets with shrimp and small fishes. Most calves continue to nurse for another year after beginning to eat solid food. Female belugas are old enough to reproduce at around 4 to 7 years of age and males around 7 to 9 years. Their lifespan is thought to be about 35-50 years.

Belugas are extremely social animals that typically migrate, hunt, and interact together in groups of 10 to several hundred. They are known as the "canaries of the sea," because they produce a vast repertoire of sounds including whistles, squeals, moos, chirps, and clicks . They have a well-developed sense of hearing and echolocation, and are reported to have acute vision both in and out of water. Belugas are opportunistic feeders, eating octopus, squid, crabs, shrimp, clams, mussels, snails, sandworms, and fishes, including anadromous eulachon and salmon and marine species such as capelin, cod, herring, smelt, flounder, sole, sculpin, lamprey, and lingcod.

Habitat
Beluga whales are generally found in shallow coastal waters, often in water barely deep enough to cover their bodies, but have also been seen in deep waters. They seem well adapted to both a cold ocean habitat and a warmer freshwater habitat. Belugas can be found swimming among icebergs and ice floes in the waters of the Arctic and subarctic, where water temperatures may be as low as 32° F (0° C). They can also be found in estuaries and river basins.

In April 2009, NMFS solicited public comments and information in an Advance Notice of Proposed Rulemaking (74 FR 17131 [pdf]) to designate critical habitat for Cook Inlet beluga whales.

Beluga Whale Range Map
(click for larger view PDF)

Distribution
Beluga whales are circumpolar in distribution. Beluga whales inhabit the Arctic and subarctic regions of Russia, Greenland, and North America. They inhabit the Arctic Ocean and its adjoining seas, including the Sea of Okhotsk, the Bering Sea, the Gulf of Alaska, the Beaufort Sea, Baffin Bay, Hudson Bay, and the Gulf of St. Lawrence. During certain times of the year, belugas may also be found in large rivers, such as the Yukon, as they seem to be unaffected by salinity changes.

Population Trends
Five distinct stocks of beluga whales occur in the United States, all in Alaska:

Cook Inlet
Bristol Bay
Eastern Bering Sea
Eastern Chukchi Sea
Beaufort Sea

Of the five stocks, the Cook Inlet stock is the most isolated; genetic samples suggest these whales have been isolated for several thousand years. The Cook Inlet stock has been severely reduced in numbers over the last several decades. NMFS estimates this population numbered as many as 1,300 in the late 1970s. By 1994, the estimate was only about 650. The current estimate is about 280 whales. The Cook Inlet stock of beluga whales is designated as depleted under the Marine Mammal Protection Act (MMPA) and was recently listed as endangered under the Endangered Species Act (ESA).

All 4 of the other stocks are considered stable or have not exhibited a decreasing trend in numbers. Population size estimates from the most recent Stock Assessment Reports are (approximately):

Bristol Bay: 1,600 individuals
Eastern Bering Sea: 18,000 individuals
Eastern Chukchi Sea: 3,700 individuals,
Beaufort Sea: 40,000 individuals

Threats
Belugas are the only cetacean with skin thick enough to be used as leather when tanned. For this and other reasons they have been harvested over the years. Human-caused mortality, primarily legal subsistence harvest by Alaska Natives, has been the most significant source of mortality of this species during recent times. Subsistence harvest is the only factor that can be identified as influencing the decline of the Cook Inlet population from 1994 to 1998 when 67 whales per year were harvested, prompting the "depleted" designation under the MMPA. The lack of recovery of the population after these harvests were curtailed was a factor that contributed to the recent ESA listing. Moreover, Cook Inlet is highly developed, and human activity is expected to increase in the future. Potential human-caused threats to this population include shipping, oil and gas production and transport, indirect and direct adverse effects from commercial fishing gear (e.g., gillnets) and operations, pollution, habitat destruction and alteration, harassment due to increasing commerce and recreation in Cook Inlet, and noise.

The other 4 stocks have levels of subsistence harvest that do not threaten their survival, and hence those stocks are not considered "strategic" stocks under the MMPA.

Bycatch in various commercial fisheries sometimes occurs but does not appear to be a threat to any of the stocks.

Natural threats from predation are also potentially of concern. Natural predators of belugas are polar bears and killer whales. Predation by killer whales is estimated at least 1 animal per year. According to some population models, this is just below a level that would lead to population declines. Beluga whales trapped by ice are often susceptible to predation by polar bears, starvation, and suffocation. Strandings are common in this population and seem to result from avoidance of killer whales plus other unknown causes. The low reproductive rate of beluga whales is also a concern.

Conservation Efforts
NMFS developed a conservation plan [pdf] under the MMPA that details many proposed and current conservation actions. The plan sets a goal of a minimum population of 780 animals before NMFS would no longer consider this stock depleted. Achievement of this goal is expected to take a minimum of 30 years. Management of the Alaskan Native subsistence fishery in Cook Inlet occurs through a Cooperative Agreement between NMFS and the Cook Inlet Marine Mammal Council. A separate co-management agreement is in place for the native subsistence fishery for the other 4 stocks. These groups set harvest limits and other requirements to ensure conservation of the species.

Regulatory Overview
On March 3, 1999, NMFS received two petitions to list the Cook Inlet population of beluga whales as endangered under the ESA. The petitioners requested that we promulgate an emergency listing under section 4(b)(7) of the ESA, designate critical habitat for Cook Inlet beluga whales, and take immediate action to implement rulemaking to regulate the harvest of these whales.

In May 2000, NMFS designated Cook Inlet beluga whales as depleted under the Marine Mammal Protection Act. However, at that time, the agency determined that the Cook Inlet beluga whale DPS was not threatened or endangered under the ESA. Because this stock did not show significant evidence of recovery thereafter, NMFS initiated a second Status Review in the spring of 2006.

In April 20, 2006, the Trustees for Alaska petitioned NMFS to list the Cook Inlet beluga whale as threatened or endangered under the ESA. NMFS evaluated the petition and conducted a status review.

In October 2008, NMFS determined that beluga whales needed protection under the ESA, and on October 22, 2008, listed the population as endangered.

In April 2009, NMFS solicited public comments and information in an Advance Notice of Proposed Rulemaking to designate critical habitat for Cook Inlet beluga whales.

Key Documents
(All documents are in PDF format.)

Title	Federal Register	Date
Advance Notice of Proposed Rulemaking to Designate Critical Habitat for Cook Inlet Beluga Whales	74 FR 17131	04/14/2009
Final Rule to List Cook Inlet Beluga Whale as Endangered	73 FR 62919	10/22/2008
Conservation Plan for Cook Inlet Beluga Whale	n/a	10/2008
Draft Conservation Plan for Cook Inlet	70 FR 12853	03/16/2005
Long-term Harvest Limits for Cook Inlet DPS	73 FR 60976	10/15/2008
2008 Status Review for Cook Inlet	n/a	04/2008
Status Review Supplement for Cook Inlet (2008)	n/a	10/2008
2006 Status Review for Cook Inlet	71 FR 14836	03/24/2006
6-Month Extension Regarding Petition to List the Cook Inlet Beluga Whale DPS Under the Endangered Species Act	73 FR 21578	04/22/2008
Proposed Endangered Status for the Cook Inlet Beluga Whale "Distinct Population Segment" (DPS)	72 FR 19854	04/20/2007
90-Day Finding for a Petition To List the Cook Inlet population as Endangered under the ESA	71 FR 44614	08/07/2006
Depleted Designation for Cook Inlet population	65 FR 34590	05/31/2000
Stock Assessment Reports	n/a	various

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