North Pacific Right Whale
About the Species
North Pacific right whales are one of the rarest of all large whale species and among the rarest of all marine mammal species. Two other species of right whale exist in the world’s oceans: the North Atlantic right whale, which is found in the North Atlantic Ocean, and the southern right whale, which is found in the southern hemisphere. North Pacific right whales are baleen whales, which feed by straining huge volumes of ocean water through their comb-like baleen plates that trap copepods and other zooplankton.
Commercial whaling greatly reduced right whale populations in the Pacific Ocean. Whaling is no longer a threat, but human activity such as entanglement in fishing gear and marine debris, vessel strikes, impacts from climate change, Oil and gas development, and ocean noise, continue to endanger this species.
NOAA Fisheries is committed to conserving and protecting the North Pacific right whale. Our scientists and partners use a variety of innovative techniques to study, and protect this species.
North Pacific right whales have been listed as endangered under the Endangered Species Act since 1970 and are depleted under the Marine Mammal Protection Act. There are no reliable estimates of current abundance or trends for right whales in the North Pacific. There are likely fewer than 500 North Pacific right whales remaining, and most sightings have been of single whales, though small groups have been sighted. Only about 30 individuals are estimated to remain of the Eastern stock that visits Alaskan waters.
The North Pacific right whale has a stocky black body, although some individuals have white patches on their undersides. They have no dorsal fin, a large head that is about a quarter of its body length, and raised patches of rough skin, called callosities, on the head, over its eyes, behind the blowhole, and around the mouth. The tail is broad, deeply notched, and all black with a smooth trailing edge. Females are slightly larger than males.
Behavior and Diet
Right whales are baleen whales, so they filter their food by straining huge volumes of ocean water through their baleen plates, copepods and other zooplankton such as shrimp. Right whales feed from spring to fall and in winter in certain areas. Their primary food sources are zooplankton, including copepods, euphausiids, and cyprids. Unlike some other baleen whales, right whales are skimmers: they feed while moving with their mouth open through patches of zooplankton.
Where They Live
Right whales have occurred historically in all the world's oceans from temperate to subpolar latitudes. Contemporary sightings of right whales have mostly occurred in the central North Pacific and Bering Sea. Sightings have been reported as far south as central Baja California in the eastern North Pacific, as far south as Hawaii in the central North Pacific, and as far north as the sub-Arctic waters of the Bering Sea and sea of Okhotsk in the summer. Since 1996, right whales have been observed repeatedly in their Critical Habitat in the southeastern Bering Sea during the summer months. Migration patterns of the North Pacific right whale are unknown, although it is thought the whales spend the summer in far northern feeding grounds and migrate south to warmer waters, such as southern California, during the winter. From 1965 to 1999, years during which the U.S.S.R. harvested North Pacific right whales illegally, there were only 82 sightings of right whales in the entire eastern North Pacific, with the majority of those occurring in the Bering Sea and nearby areas of the Aleutian Islands. Calving grounds have not been found in the eastern North Pacific. Worldwide, most known right whale nursery areas are in shallow, coastal waters.
Lifespan & Reproduction
Using cross-sections of teeth is one way to determine a mammal’s age. However, right whales have no teeth. Therefore, ear bones and, in some cases, eye lenses can be used to estimate age in right whales after they have died. It is believed that right whales live to at least 70 years, but there are little data on longevity.
Right whales probably mate around 8 years old. Females give birth to their first calf at an average age of 9 to 10 years. Females are pregnant for about 12 to 13 months and produce a calf approximately every three to five years. Calves are born able to swim, and mothers and calves form a very close attachment. Calves stay close to their mothers, swimming up on their backs or butting them with their heads. Mother may roll over on their backs and hold their calves in their flippers. Calves are usually weaned toward the end of their first year.
Because of their rarity and scattered distribution, it is nearly impossible to assess the threats to this species, but possible threats include:
Vessel strikes can injure or kill North Pacific right whales. Vessel strikes are a primary cause of death in North Atlantic right whales, and it is likely that North Pacific right whales are also vulnerable to this threat. As Arctic sea ice continues to decline, the projected increase in ship traffic from the opening of trans-polar shipping routes will increase the risk of vessel strikes, and also increase ambient noise and pollution.
North Pacific right whales can become entangled in fishing gear and marine debris, either swimming off with the gear attached or becoming anchored. While there are very few known entanglements of North Pacific right whales, entanglement in fishing gear, including traps, pots, or gillnets, is a significant source of mortality for North Atlantic right whales, and has been documented on Western Arctic bowhead whales which seasonally occupy the same areas as North Pacific right whales. Once entangled, whales may drag attached gear for long distances, ultimately resulting in fatigue, compromised feeding ability, or severe injury, which may lead to reduced reproductive success and death.
Underwater noise pollution interrupts the normal behavior of right whales by reducing their ability to communicate, increasing their stress levels, interrupting their normal behavior, and displacing them from areas important to their survival. If loud enough, ocean noise can cause temporary or permanent hearing loss.
Biotoxins from Harmful Algal Blooms
Harmful algal blooms (HABs) have been documented in North Atlantic and southern right whales and identified as a threat to both populations. It has been suggested that effects from HABs could heighten the whales’ susceptibility to both ship strikes and entanglements. There is concern about the emerging prevalence of algal toxins in habitat used by North Pacific right whales. Due to lack of access to the species, algal toxins have not been found in North Pacific right whales; however, they have been documented in bowhead whale carcasses in the Arctic, which can be used as a proxy for right whales. Domoic acid and saxitoxin was present in 68 percent and 32 percent, respectively, of bowhead whale carcasses examined from the Arctic, the highest prevalence of the 13 species examined in a study looking at harmful algal blooms in Arctic marine mammals.
The impacts of climate change on baleen whales are unknown, but it is considered one of the largest threats facing remote habitat in the North Pacific. Most notably, the timing and distribution of zooplankton prey is largely governed by sea ice coverage and could change dramatically with altered oceanographic conditions. Changes in zooplankton distribution could lead to nutritional stress and diminished reproduction for North Pacific right whales. Additionally, changing water temperature and currents could impact the timing of environmental cues important for navigation and migration, and the location of critical habitat within the North Pacific right whale range. Changes in ice extent, density, and persistence could alter the dynamics of the Bering Sea shelf zooplankton community, and in turn, affect the foraging behavior and success of right whales.
Eastern and Western Populations
North Pacific right whales are considered to exist in two populations based on geographic distribution: eastern and western North Pacific. The range of eastern North Pacific right whales is believed to encompass the Gulf of Alaska and the Bering Sea, while the western population ranges from near the Commander Islands, the coast of Kamchatka, along the Kuril Islands and in the Sea of Okhotsk.
There are few reliable estimates of the current number of North Pacific right whales, but it is thought to be in the low 100s. There may have been as many as 37,000 North Pacific right whales before commercial whaling drastically reduced populations in the 19th century.
The eastern population of North Pacific right whales is one of the smallest large whale populations in U.S. waters. The eastern population may only have only 30 animals. After being hunted extensively in the nineteenth century, they were protected by international treaties in the 1930s and 1940s. Despite these protections, illegal Soviet whaling in U.S. waters during the 1960s decimated the already reduced population, and there have been no signs of recovery since. In fact, for many years, the whales were so rarely seen that sightings of individuals warranted publication.
Since 1996, North Pacific right whales have been found repeatedly in or near their Critical Habitat, a small area of the southeastern Bering Sea. Even though there have been substantial research efforts in this area in certain years, the entire photographic identification catalog of Bering Sea right whales (as of 2017) only includes 23 individuals, and the genetics archive contains only 21 individuals.
The population in the Bering Sea is thought to number only about 28 whales, with 20 males and eight females. The small number of females is of great concern, and relatively few calves and juveniles have been seen in the last few decades (one in 2002, two in 2004, and one in 2017). Even fewer whales have been seen in the Gulf of Alaska, with only a few individuals ever identified (in 2005, 2006, 2013, and 2017). During recent ship surveys in the Gulf of Alaska in 2009 and 2013, no right whales were seen, but at least three individuals were detected acoustically.
Dedicated aerial surveys, ship surveys, and satellite tagging research on North Pacific right whales in the Bering Sea have not been conducted since 2010 due to a lack of funding. The only current field research on North Pacific right whales consists of several acoustic recorders in the Bering Sea that can detect their occurrence.
The area inhabited by North Pacific right whales from the western stock includes Russian and Japanese territorial and exclusive economic zone waters and some international waters, even in the center of the Sea of Okhotsk. As a result, surveys for whales have generally not been comprehensive. Therefore, information on distribution and abundance from the western stock is limited, and its status is currently unknown.
The only existing estimate of the western North Pacific right whale population comes from three Japanese minke whale sighting surveys in the Sea of Okhotsk conducted between 1989 and 1992. This estimate was 922 animals; however, biases were identified in the survey methodology, and the estimate should be considered unreliable given its low precision. The population estimate for the western stock is likely in the low hundreds.
In the western North Pacific, recent sightings of right whales have been reported. These include five observations of a total of ten animals in June 2012 in offshore waters some 290 miles southeast of Kamchatka, together with a pair of whales recorded in June 2013 east of the Kuril Islands. A breaching right whale was observed during a sightseeing cruise off the Shiretoko Peninsula of Japan in July 2013 making it the first confirmed sighting in the area for several decades and the first recorded in Hokkaido. In February 2015, a young right whale was found entangled in aquaculture gear at Namhae, South Korea and successfully released, making it the first record of this species in the Sea of Japan in 41 years. In October 2016, an entangled right whale was reported to have died while being disentangled in Volcano Bay, Hokkaido, Japan.
In the Spotlight
The North Pacific right whale has been listed as endangered under the Endangered Species Act since 1973 when it was listed as the "northern right whale." It was originally listed as endangered under the Endangered Species Conservation Act, the precursor to the ESA, in June 1970. The species is also designated as depleted under the Marine Mammal Protection Act.
Recovery Planning and Implementation
Under the ESA, NOAA Fisheries is required to develop and implement recovery plans for the conservation and survival of listed species. NOAA Fisheries appointed a recovery team to assist with the development and implementation of a Draft Recovery Plan for the Northern Right Whale (including both the North Atlantic and North Pacific right whales), which was distributed for public comment in February 1990. In December 1991, the Final Recovery Plan for the Northern Right Whale was approved. NOAA Fisheries reclassified Northern right whales into two species, North Atlantic right whales and North Pacific right whales, and each species has its own recovery plan. The North Pacific right whale plan was most recently revised in 2013, NOAA Fisheries announced the availability of the North Pacific Right Whale Recovery Plan.
The goal of the plan is to recover the species, with an interim goal of down-listing their status from "endangered" to "threatened."
The major actions recommended in the plan are:
- Reduce or eliminate injury or mortality caused by ship collision
- Reduce or eliminate injury and mortality caused by fisheries and fishing gear
- Protect habitats essential to the survival and recovery of the species
- Minimize effects of vessel disturbance
- Continue international ban on hunting and other directed takes
- Monitor the population size and trends in abundance of the species
- Maximize efforts to free entangled or stranded right whales and acquire scientific information from dead specimens
NOAA Fisheries initiated a 5-year review of the North Pacific right whale under the ESA. The review was completed in 2017 and concluded that due to insufficient data, a high demographic risk, and major risks that are not well understood, this species remains endangered.
Once a species is listed under the ESA, NOAA Fisheries evaluates and identifies whether any areas meet the definition of critical habitat. Those areas may be designated as critical habitat through a rulemaking process.
The designation of an area as critical habitat does not create a closed area, marine protected area, refuge, wilderness reserve, preservation, or other conservation area; nor does the designation affect land ownership. Federal agencies that undertake, fund, or permit activities that may affect these designated critical habitat areas are required to consult with NOAA Fisheries to ensure that their actions do not adversely modify or destroy designated critical habitat.
In 2008, NOAA Fisheries designated critical habitat for the North Pacific right whale. In 2022, NOAA Fisheries initiated a review of the currently designated critical habitat to determine whether revision is warranted.
Addressing Ocean Noise
Underwater noise threatens whale populations, interrupting their normal behavior and driving them away from areas important to their survival, such as feeding and breeding grounds. Increasing evidence suggests that exposure to intense underwater sound in some settings may cause some whales to strand and ultimately die. NOAA Fisheries is investigating all aspects of acoustic communication and hearing in marine animals, as well as the effects of sound on whale behavior and hearing. In 2016, we issued technical guidance for assessing the effects of anthropogenic (human-caused) sound on marine mammal hearing.
Overseeing Marine Mammal Health and Stranding Response
We work with volunteer networks in all coastal states to respond to marine mammal strandings including all whales. When stranded animals are found alive, NOAA Fisheries and our partners assess the animal’s health and determine the best course of action. When stranded animals are found dead, our scientists work to understand and investigate the cause of death. Although the cause often remains unknown, scientists can sometimes attribute strandings to disease, harmful algal blooms, vessel strikes, fishing gear entanglements, pollution exposure, and underwater noise. Some strandings can serve as indicators of ocean health, giving insight into larger environmental issues that may also have implications for human health and welfare.
Marine Mammal Unusual Mortality Events
North Pacific right whales have never been part of a declared unusual mortality event. Under the Marine Mammal Protection Act, an unusual mortality event is defined as "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response." To understand the health of marine mammal populations, scientists study unusual mortality events.
Right whales were first protected by the 1931 Convention for the Regulation of Whaling, which took effect in 1935. However, neither Japan nor the Soviet Union signed this agreement. In 1949, the International Convention for the Regulation of Whaling protected right whales from commercial whaling.
The North Pacific right whale has been listed as endangered under the Endangered Species Act (ESA) since 1973 when it was listed as the "northern right whale." It was originally listed as endangered under the Endangered Species Conservation Act, the precursor to the ESA, in June 1970. The species is also designated as depleted under the Marine Mammal Protection Act in 1973.
In 2005, the Center for Biological Diversity petitioned NOAA Fisheries to list the North Pacific right whale (formerly the "northern right whale") under the ESA. In March 2008, we reclassified the endangered northern right whale as two separate, endangered species: North Pacific right whale (E. japonica) and North Atlantic right whale (E. glacialis). In April 2008, NOAA Fisheries issued a final rule to designate critical habitat for the North Pacific right whale.
Key Actions and Documents
NOAA Fisheries conducts research activities on the biology, behavior, and ecology of right whales. The results of this research are used to inform management decisions and enhance recovery efforts for this endangered species.
Determining the number of right whales in each population and whether a stock is increasing or decreasing over time helps resource managers assess the success of enacted conservation measures. Our scientists collect information and present these data in annual stock assessment reports.
NOAA Fisheries also conducts research on the acoustic environment of cetaceans, including right whales. Acoustics is the science of how sound is transmitted. This research involves methods to locate right whales using passive acoustic arrays.
Recent Science Blogs
12-Month Finding on a Petition to Revise the Critical Habitat Designation for the North Pacific Right Whale (23-R139)
We, NMFS, announce a 12-month determination on a petition to revise the critical habitat…
Biological Opinion on the effects of the proposed construction of a cruise ship berth and…
Endangered Species Act (ESA) Section 7(a)(2) Biological Opinion Office of Naval Research (ONR)…
Data & Maps
Distribution and Relative Abundance of Marine Mammals in the Eastern Chukchi Sea, Eastern and…
Tracks the implementation of recovery actions from Endangered Species Act (ESA) recovery plans.
This report describes field activities of the Aerial Surveys of Arctic Marine Mammals (ASAMM)…