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North Pacific Right Whale (Eubalaena japonica)

Range and Habitat: Sea of Okhotsk, Bering Sea, and northern North Pacific Ocean
North Atlantic Right Whale
North Pacific Right Whale (Photo: Brenda Rone)

Status under U.S Law:

ESA- Endangered
MMPA - Depleted

Conservation issues:
Small population size, ship collisions, entanglement in fishing gear, oil spills, offshore oil and gas exploration and development
Physical characteristics: At Birth Maturity
Length 4-4.6 m
(13 -15 ft)
15 - 18.3 m
(49 - 60 ft)
Weight 910 kg
(2,000 lb)
Up to 60,000 kg
(132,000 lb)


> 70 years

North Pacific right whales were severely depleted by commercial whaling and are now among the world's most endangered mammals. Two populations are thought to survive: one in the western North Pacific off of Russia, and the other in the eastern North Pacific off Alaska and coastal North America. The status of both populations is poorly known. The western population is thought to number in the low hundreds although reliable information to support that estimate is limited (Allan and Angliss 2014). The eastern population appears to number a few tens of animals, making it the most endangered marine mammal population in U.S. waters and perhaps the most endangered large whale population in the world (Wade et al 2010).

Prior to commercial whaling, there were likely over 20,000 right whales in the North Pacific. Intensive whaling in the mid- to late 1800s nearly eliminated them before hunting of right whales was prohibited by international convention in 1935. The population apparently began to recover in the mid-1900s, but in the 1960s illegal Soviet whaling killed an estimated 681 right whales in the North Pacific and adjacent Okhotsk and Bering Seas (Ivashchenko et al. 2009 and 2013). This catch in the northern Gulf of Alaska and southeast Bering Sea virtually eliminated the eastern population. Between the late 1960s and the mid-1990s sightings of right whales in the eastern North Pacific were rare, widely scattered, and almost always of solitary animals. Then, in the summer of 1996, a group of four animals was reported in the southeastern Bering Sea (Goddard and Rugh 1998). Each year since then, the National Marine Fisheries Service has undertaken aerial, shipboard, and/or acoustic surveys of this area during the summer to assess their status.

The best estimate of current population size, based on photo identification and genetic samples of animals seen in the Bering Sea through the summer of 2010, is just 31 (95% CL = 23-54) individuals (Wade et al 2010). Although there is some evidence of calving, the location of winter calving ground and other winter habitat is unknown. In 2006 the National Marine Fisheries Service designated two areas as critical habitat (71 Fed. Reg. 38277) based largely on summer sightings locations gathered since 1996 and passive acoustic detections since 2000: a large area in the eastern Bering Sea and a small area south of Kodiak Island in the Gulf of Alaska. A recovery plan for the species was adopted by the agency in 2013.

Figure 1. North Pacific right whale sighting locations from 1973 to 2006 and designated critical habitat areas.


From 2007 to 2010 almost all research on eastern North Pacific right whales was focused in the southeast Bering Sea critical habitat area and was funded by the Minerals Management Service (now the Bureau of Ocean Energy Management). Those funds, approximately $1 million per year, were transferred to the National Marine Fisheries Service to collect data on right whales for use in analyzing plans for oil and gas exploration and development in the Southeast Bering Sea. However, after plans for lease sales in the Bering Sea were canceled in 2009, the Bureau withdrew funding for further right whale studies. Since then the National Marine Fisheries Service has not included requests for North Pacific right whale research in its budget requests to Congress. As a result, almost no work (other than maintenance of four acoustic buoys supported with Bureau of Ocean Energy Management funds to detect right whale calls in the Bering Sea) has been undertaken to collect information on this endangered population. Although there are no current plans for oil and gas exploration and development in the southeast Bering Sea, interest in the area could be revived in future plans. There also is uncertainty about the northern extent of the right whale range in the northern Bering or even Chukchi Seas and seasonal reductions of sea ice could enable right whales to move further north in summer months. Given ongoing oil and gas development in Arctic waters off Alaska, it is possible that these activities could affect right whales.

Recognizing the pressing need for information to evaluate and support North Pacific right whale management activities, the Marine Mammal Commission has dedicated an increased portion of its Fiscal Year 2014 appropriation for work on this species. As this update was being prepared, the Commission was investigating ways to use those funds to analyze acoustic data from the eastern North Pacific with the goal of identifying other important, but currently unknown, right whale habitats.

North Pacific Right Whale Recovery Plan

On 20 March 2012 the Center for Biological Diversity, a non-governmental environmental organization, filed a notice of intent to sue the National Marine Fisheries Service for failing to develop a recovery plan for North Pacific right whales under the Endangered Species Act. To avoid the suit, the agency agreed to prepare a recovery plan for the species. On 23 January 2013, the Service circulated a draft recovery plant for public review (78 FR 4835).

The Commission provided comments to the Service on the draft plan on 11 March 2013. In part the Commission recommended that the plan clarify that there was considerable uncertainty about the size of the western North Pacific population. Noting that it would be impossible to adequately assess risks from human activities, particularly from ship collisions and entanglement in fishing gear, without knowing where remnants of the eastern North Pacific right whale population occur throughout the year, the Commission also recommended that the plan (1) redefine its primary plan goal to focus initially on identifying the species’ seasonal movement and habitat-use patterns; (2) include a new section in the plan identifying and describing the research needed to determine right whale movements and habitat-use patterns; and (3) assign a priority one ranking to research tasks most important for identifying seasonal movements and habitats.

On 3 June 2013, the Service adopted a final recovery plan for North Pacific right whales (National Maine Fisheries Service 2013) that incorporated the Commission’s comment. It noted that the primary purpose of the plan is to provide a research strategy to obtain data necessary to determine seasonal movements and habitat use patterns. It noted that this was necessary to provide a basis for understanding whether and how threats may be limiting the species recovery and what might be done to minimize potential threats. Among the tasks identified to assess the species distribution and movements were aerial and ship board surveys, acoustic monitoring, and satellite telemetry tags. Cost estimates for those and related studies over the next five years were estimated to cost at least $14.5 million.

Links for Additional Information

Commission Reports and Related Publications:

See North Pacific Right Whale sections in chapters on Species of Special Concern in past Annual Reports to Congress (Link to Past MMC Annual Reports)

Endangered, Threatened, and Depleted Marine Mammals in U.S. Waters - A Review of Species Classification Systems and Listed

The Status of Protection Programs for Endangered, Threatened, and Depleted Marine Mammals in U.S. Waters

Commission Letters:

To view recent Commission letters concerning North Pacific right whales choose a date below

March 11, 2013 - on a draft North Pacific right whale recovery plan

December 14, 2007 - on proposed critical habitat areas

February 22, 2007 on proposed rules to list North Atlantic and North Pacific right whales separately under the Endangered Species Act

January 3, 2006 on proposed critical habitat areas

Additional Links:

National Marine Fisheries Service - Office of Protected Species - North Pacific Right Whale

National Marine Fisheries Service - Stock Assessment Reports

Alaska Fisheries Science Center - Detecting Right Whales Using Passive Acoustics in SE Bering Sea

Alaska Department of Fish and Game - North Pacific Right Whales

Wikipedia - North Pacific Right Whale






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