Species Status

Abundance and Trends

Worldwide polar bear numbers are estimated to be around 23,000 animals (Hamilton and Derocher, 2018). Polar bears are distributed among 19 populations, two of which occur in U.S. waters: the Chukchi/Bering Seas population and the Southern Beaufort Sea population. Because polar bear habitat is vast and difficult to access, reliable abundance estimates are difficult to obtain. The best estimates of population size for the two U.S. populations are provided in the stock assessment reports prepared by FWS under the Marine Mammal Protection Act (MMPA). These reports estimate 2,000 bears in the Chukchi/Bering Seas population (based on extrapolated data that were collected in the 1990s) and 900 bears in the Southern Beaufort Sea population (based on a capture-recapture analysis from 2004 to 2010).

The International Polar Bear Specialist Group (PBSG) in early 2015 found data deficiencies for the Chukchi/Bering Seas population, indicating that any abundance estimates and trend assessments are considered unreliable. In 2016, U.S. and Russian researchers conducted aerial surveys using thermal imaging to try to obtain an updated and more reliable population estimate of the Chukchi/Bering Seas polar bear population. This study, published in 2021, estimated the 2016 polar bear abundance in the Chukchi Sea to be between 3,435 and 5,444 bears. A separate study published in 2018 estimated that the average abundance of this population from 2008 to 2015 was approximately 2,900 bears.

A study published in 2020 estimated the abundance of the Southern Beaufort Sea population at 1,300 bears in 2003, a decline to 525 bears in 2006, and then relative stability between 2006 and 2015, with an estimated 573 bears in 2015. These trends and abundance estimates were also supported by a study published in 2021. New modeling methods, that incorporate resource selection, are currently being developed to help reduce the uncertainty associated with polar bear abundance estimates. In addition, a joint effort between the U.S. and Canada is working to produce a new population-wide abundance estimate.

Distribution

Polar bears inhabit the circumpolar Arctic and portions of the subarctic on sea-ice and along coastal areas and islands. Although they sometimes range into international waters, polar bears generally occur in areas under the jurisdiction of five countries: Canada, Greenland (Denmark), Norway, Russia, and the United States (Alaska). Scientists and managers recognize 19 relatively discrete subpopulations, two of which occur in the United States. The Chukchi/Bering Seas population is shared with Russia and the southern Beaufort Sea is shared with Canada.

Cooperative Conservation Efforts

As a party to the 1973 Agreement on the Conservation of Polar Bears, the United States works internationally to pursue the conservation of polar bears and their habitat. The five “Range States” that are parties to the agreement (Canada, Denmark (Greenland), Norway, Russia, and the United States) met in Greenland in September 2015 to discuss a variety of research and management issues. At that meeting, the Range States adopted a circumpolar conservation plan for the species and a two-year implementation schedule. In 2020, the Polar Bear Range States reviewed their progress in achieving their conservation objectives and created a more detailed implementation plan for 2020-2023.

Under a bilateral agreement between the United States and Russia regarding the shared Chukchi/Bering Seas population, the two countries jointly manage this population, including the adoption of annual sustainable harvest limits. At its 2016 meeting the U.S.-Russia Polar Bear Commission agreed to retain the previously adopted annual harvest limit of 58 bears, and in 2018, increased the limit to 85 bears, no more than one-third of which can be female.

In early 2017, the Indigenous People’s Council for Marine Mammals (IPCoMM) convened a meeting of village representatives concerning the establishment of a new Alaska Native organization to engage in co-management of polar bears. Subsequent meetings culminated in the formation of a new organization, the Alaska Nannut Co-Management Council (ANCC), which has been recognized by the FWS as the successor entity to the Alaska Nanuuq Commission under section 501(2) of the MMPA. The council consists of members from 15 tribes that have traditionally harvested polar bears for subsistence. Currently, the ANCC is working with the FWS and local communities to develop a harvest management plan.

What the Commission Is Doing

The Marine Mammal Commission is working closely with the FWS to promote the conservation of polar bears. The Commission participates on U.S. delegations to international polar bear meetings and participated on the polar bear recovery team that developed the Polar Bear Conservation Management Plan. In those capacities, the Commission is integrally involved in advising the FWS and others on conservation needs and priorities for the species and on steps needed to meet U.S. obligations under the two applicable international agreements.

Polar Bear Summit

In coordination with FWS, the Alaskan Nanuuq Commission, Kawerak, and the North Slope Borough, the Commission co-convened a summit on June 1-2, 2016 in Nome, AK, to promote the co-management of polar bears for subsistence use, especially in relation to the agreement with Russia on the conservation and management of the Alaska-Chukotka stock. This meeting allowed federal managers and Alaska Natives to consider options available for implementing U.S. responsibilities under the agreement and provided useful background for the ongoing efforts to form a new Alaska Native organization for polar bears.

Comments on Advance Notice of Proposed Rulemaking

On 9 January 2017, the Commission provided comments to the Fish and Wildlife Service in response to an advance notice of proposed rulemaking seeking input on developing a regulatory program and local management structures to carry out U.S. responsibilities under the United States-Russia Polar Bear Agreement and Title V of the MMPA. The Commission noted that the expectation has always been that U.S. implementation of the agreement would be achieved jointly by the FWS and an Alaska Native partner and that this continues to be the preferred path. The Commission also believed that it should be left largely to the Alaska Native communities to decide how they want to be represented. The Commission supported the adoption of regulations that recognize shared management and enforcement responsibilities and suggested two alternatives for providing the new Alaska Native organization with the necessary legal authority to carry out those functions.

Commission Reports and Publications

For historic information about polar bears and Commission-related activities, see our 2012 annual report.

Commission Letters

Learn More

Threats

The primary threat to the polar bear is the predicted loss of sea-ice and associated prey base. Other potential threats include oil spills and contaminants, unsustainable removals (e.g., in defense of life or for subsistence), loss of denning habitat, disease, and disturbance from increasing activities in the Arctic. Polar bears are increasingly summering on land in response to sea-ice loss, and models estimate that 80-100 percent of polar bears in the Chukchi Sea and 61-97 percent of bears in the southern Beaufort Sea will spend more than 3 weeks on land by 2065. Recent research efforts by the USGS have assessed how sea-ice loss and altered habitat use affect polar bear home range size, exposure to pathogens and contaminants, body condition, and reproduction.

Current Conservation Efforts

Due primarily to the predicted loss of sea-ice in Arctic waters over the coming decades, the FWS listed the polar bear as a threatened species in 2008. The FWS designated much of the area inhabited by polar bears in Alaska as critical habitat in 2010. That designation, vacated in 2013 by the U.S. District Court in Alaska, was reinstated by a 29 February 2016 ruling of the Ninth Circuit Court of Appeals.

The Endangered Species Act requires that the FWS develop a recovery plan for listed species, including the polar bear. The FWS published its Polar Bear Conservation Management Plan on 20 December 2016 to meet that requirement and to serve as a conservation plan under the MMPA. The plan concluded that range-wide persistence of polar bears will likely require stabilizing greenhouse gas emissions by the middle of this century. Other threats to polar bears were found to be mostly insignificant compared to the risk of extinction posed by climate change and the associated loss of sea ice.

In addition, the five polar bear range states developed a circumpolar action plan for polar bears in 2015, drawing on each country’s national plan. This 10-year plan aims to strengthen range-wide polar bear conservation efforts.

In 2023, FWS completed a 5-year status review and determined that the polar bear should maintain its classification as a threatened species under the Endangered Species Act. In the review, sea ice decline was again identified as the primary stressor affecting all aspects of polar bear life history and threatening polar bear persistence and recovery.

The Commission will continue to play an active role in advising the FWS and others on polar bear conservation matters. The Commission also will continue to play an oversight role regarding implementation of U.S. obligations under the applicable international agreements.

Species Status

Abundance and Trends

The western North Pacific population of gray whales is listed as an endangered distinct population segment under U.S. law and it is an endangered subpopulation according to the the Red List of the International Union for Conservation of Nature (IUCN). The population (stock) structure of gray whales has long been under investigation (Supplement 22: 166-174). There are multiple feeding aggregations and multiple stocks but there is also much uncertainty about stock delineation. In the western North Pacific, a Western Feeding Group feeds off Sakhalin Island and southern Kamchatka. This group may include whales that breed in Asia and others that breed largely with one another while migrating to Mexico in the late autumn. In 2020, based on photo-identification and genetic data, an estimated 220-270 whales (excluding calves) were regularly feeding in the summer and early autumn off Sakhalin, the number having more than doubled since the early 2000s.

Distribution

Photographic and genetic matches, as well as satellite tracking results, have shown that some of the Sakhalin-Kamchatka whales, after foraging in summer and fall in the western North Pacific, migrate across the southern Bering Sea and Gulf of Alaska to Canada and the U.S. Pacific Northwest, then southward to Mexico for the winter. At least some of those whales then return to Russia in the spring.

The migratory routes and winter habitats of other Sakhalin-Kamchatka whales are uncertain. Western North Pacific gray whales historically ranged southward from the Sea of Okhotsk, along the coasts of Korea and Japan to traditional wintering areas in southern China. While there is evidence that some of those that feed off Sakhalin move south to at least Japan in the winter, it is uncertain to what extent the traditional wintering areas in Asia are still used by gray whales. A photo-identified individual moved back and forth between Sakhalin and the Pacific coast of Honshu, Japan between 2014 and 2016, and a 13-m female died in fishing gear off Baiqingxiang, China, in the Taiwan Strait in November 2011. Recent acoustic evidence from the U.S. Navy was interpreted as suggesting that some gray whales move through the East China Sea, travelling south in the fall and north in the spring.

Science Provides Clues About Whale Migration

Satellite telemetry, photo-identification, and genetic studies have documented the movements of individual gray whales between feeding areas in the western North Pacific and wintering areas in Baja California, Mexico.

A Russia-U.S. research team satellite-tagged gray whales at Sakhalin Island in 2010 and 2011. In the first successful deployment on October 4, 2010 the investigators tagged a 13-year old male gray whale in the feeding area off Piltun Lagoon along the northeastern Sakhalin coast. The whale, nicknamed “Flex,” remained within 45 km of the tagging site for 68 days and left Sakhalin on December 11. Over the next 55 days, Flex migrated across the Okhotsk Sea, the Bering Sea, and the Gulf of Alaska. The tag stopped sending signals on February 5, 2011 when Flex was 20 km off the central Oregon coast (Mate et al., 2015). Six additional tags were deployed in summer 2011 and at the end of December two tags, both attached to young females, were still functioning. These two whales moved on separate tracks away from Sakhalin, east across the Okhotsk Sea to the Kamchatka Peninsula, around its southern tip, and then eastward across the Bering Sea toward Alaska. At the end of December 2011, they were still on separate tracks, but both were southeast of the Aleutian Islands in the Gulf of Alaska. While one signal was soon lost, the transmitter on one of these whales, an 8.5-year-old female nicknamed “Varvara,” continued to transmit until the autumn of 2012. After January 1, 2012, the whale continued to travel south from British Columbia, Canada, along the west coast of the United States and Mexico to almost the southern tip of Baja California. At that point, the whale reversed course and returned north past the major nursery lagoons, along the west coast of North America to Alaska, through the Aleutians and back across the Bering Sea. These migratory movements and this whale’s presence in or near the wintering lagoons coincided with the migratory timing of eastern North Pacific gray whales. By mid-May, Varvara had returned to the original tagging area off Sakhalin where her movements were recorded until the tag ceased to function on or about October 14, 2012. The 22,511 km round trip took 172 days and at the time was believed to be the longest recorded migration of any mammal.

These fascinating tracking results spurred analyses of photo-identification and genetic data which were reported at a meeting of the International Whaling Commission Scientific Committee in 2018. As of 2019, 54 different individual gray whales were known to have visited both Russia and Mexico, confirming that at least 14% of the Sakhalin-Kamchatka whales make the trans-Pacific migration (if not annually then at least in some years) and about 0.5% of the whales that have been photo-identified in the Mexican wintering areas are known to be individuals that also visit Russia in summer and fall. In 2021 model results indicated that at least half of the Sakhalin-Kamchatka whales overwinter in the eastern North Pacific. The size of any current western North Pacific wintering population remains highly uncertain.

Genetic matches between two individual gray whales biopsy-sampled off Santa Barbara, California and known from both biopsies and photo-identification data obtained at Sakhalin provided further evidence of the connection between the western and eastern Pacific.

What the Commission Is Doing

The Commission has been closely involved in consultations and agency discussions concerning the proposal by the Makah tribe in Washington State for an MMPA waiver allowing resumption of the tribe’s subsistence hunt of gray whales. In particular, it contributed to the determination of conditions attached to the permit to ensure, to the greatest extent possible, that individuals from the western North Pacific that migrate seasonally to coastal North American waters would be fully protected. The Commission was a participating party in the public hearing on this matter, held before an administrative law judge in Seattle in November 2019.

Commission Reports and Publications

For more information on Western North Pacific gray whales, see the Commission’s 2010–2011 annual report and 2012 annual report.

Commission Letters

Learn More

Threats

The threats to gray whales in the western North Pacific include entanglement and entrapment in fishing gear, ship strikes, noise, and habitat degradation. The whales that migrate to North America for the winter face these same threats in the U.S., Canada, and Mexico. The intensity of oil and gas exploration, development, production, and transport at Sakhalin Island is of particular concern as a potential threat to the gray whales that depend on that region for foraging in the summer and fall. Two major offshore oil and gas projects are located near the Sakhalin Island feeding area, and additional projects were underway and planned off Sakhalin and in areas near the whales’ migratory routes when the flow of information from the region was disrupted. The biggest risks from such projects come from underwater noise, including seismic surveys, increased vessel traffic, habitat modification, and the possibility of a major oil spill.

As evidenced by documented deaths in fishing nets in Japan and China as well as observations of entangled animals at Sakhalin, gray whales in Russia, Japan, and China (and Korea if any of the animals still venture into those waters) face the risk of gear entanglement as well as that of vessel strike. An analysis of human-caused scarring on gray whales near Sakhalin Island found that at least 18% of individuals identified between 1994 and 2005 had been entangled at least once.

An unusual mortality event from 2019-2023 affected gray whales along the west coast of North America. Elevated numbers of gray whales in poor body condition have been stranding, and it is unknown if western and eastern North Pacific gray whales are equally affected. During the event, 690 gray whale strandings had been documented. The exact cause(s) of the event is (or are) still undetermined.

Current Conservation Efforts

The discovery of gray whales at Sakhalin Island in the 1990s coincided with growing interest in the area for offshore oil and gas development. This raised concern about the potential impacts of such development on the whales. In 2006, IUCN’s Western Gray Whale Advisory Panel (WGWAP) was established to provide independent advice and recommendations on how the operator of one of the largest oil and gas projects at Sakhalin could minimize risks to the whales and their habitat from the project’s activities, particularly seismic surveys, construction, vessel operations, and oil spills. The WGWAP was disbanded in March 2022, shortly after Russia’s invasion of Ukraine.

Also, for nearly 30 years the International Whaling Commission’s (IWC) Scientific Committee has provided an international forum for improving knowledge about western gray whales and the measures needed to conserve them. The Scientific Committee completed a range-wide review of population structure and status of gray whales throughout the North Pacific in 2018.

In 2023, NOAA Fisheries completed a 5-year review for the western North Pacific gray whale and concluded that no change to the listing status of the western North Pacific distinct population segment of gray whale was warranted at this time.

Efforts in Alaska and along the U.S. West Coast to reduce entanglement, vessel strike, and disturbance from vessels may also benefit western North Pacific gray whales that migrate to Mexico. Some of those efforts include the creation of marine mammal viewing guidelines in Alaska, the development of innovative fishing gear technologies, the modification of shipping lanes, and the implementation of vessel speed reduction programs.

Species Status

Abundance and Trends

Numerous aerial-survey, photo-identification, satellite-telemetry, and genetic studies have made the MHI insular population the world’s most thoroughly studied false killer whales. Based on photo-identification studies, its current size is estimated to number between 150 and 200 whales (best estimate = 167), which is believed to be significantly fewer than were present in the late 1980s, when aerial surveys around the MHI sighted individual groups of false killer whales in excess of 400 individuals.

The pelagic population of false killer whales in Hawaiian waters is estimated to consist of approximately 5,500 individuals, with around 2,000 of those within the Hawaiian Islands EEZ. The large pelagic range of this population along with limited large-scale surveys make it difficult to assess trends in abundance for this population. The Northwestern Hawaiian Islands population is smaller and less studied, with an estimated abundance of around 400 individuals.

Distribution

False killer whales are highly social animals that form social clusters of related individuals that travel and forage together. Within pods, individuals may spread out over many miles when hunting, while smaller sub-groups spread apart and merge over periods of hours to days. The MHI insular population consists of four social clusters that occupy waters mostly within about 45 nautical miles of shore, although some individual members have been tracked as far as 71 nautical miles away from the islands. The Hawaiian pelagic population is a transboundary stock found up to hundreds of miles from the archipelago, with groups occasionally approaching as close as roughly seven nautical miles of the MHI. The Northwestern Hawaiian Islands insular population lives within just under 60 nautical miles of the chain’s small islets and banks from Gardner Pinnacles (midway along the chain) to Kauaʻi, with occasional excursions to the west side of Oʻahu in the MHI.

What the Commission Is Doing

The Commission has been an active member of the False Killer Whale Take Reduction Team (FKWTRT) since its inception in 2010. This multi-stakeholder team makes recommendations to the National Marine Fisheries Service (NMFS) on the development and refinement of the False Killer Whale Take Reduction Plan (FKWTRP).

In 2019, the Commission held its annual meeting in Hawaii, and dedicated one session to understanding the current status of interactions between pelagic false killer whales and the deep-set longline fishery, and between insular false killer whales and State managed hook-and-line fisheries (see session summaries).

In December 2020, the Commission commented on NMFS’s proposed Recovery Implementation Strategy for the MHI insular population. The Commission recommended that the Strategy address the relative urgency of different measures, identify necessary resources and collaborations, and prioritize the monitoring of state commercial and recreational fisheries with the potential to interact with MHI insular false killer whale. The final Recovery Plan and Implementation Strategy were published in November 2021.

Commission Reports and Publications

See the false killer whale sections in chapters on Species of Special Concern in past Marine Mammal Commission Annual Reports to Congress.

Commission Letters

Learn More

Threats

The most significant threat to false killer whales in Hawaiʻi is interactions with fishing gear that lead to serious injury or death. False killer whales are attracted to longline fishing vessels, where they take (depredate) bait and hooked fish, such as mahi-mahi and yellowfin tuna. Consequently, they are sometimes caught on hooks or entangled in fishing lines. Such interactions with Hawaiʻi-based longline fisheries have become a significant conservation issue for false killer whales within Hawaiian waters and on the high seas (in other words, within and beyond the U.S. Exclusive Economic Zone (EEZ) – shore to 200 nautical miles offshore).

 The majority of false killer whale bycatch in Hawaiʻi-based longline fisheries comes from the pelagic population, as the fishery operates outside of nearshore areas where the MHI population is commonly found. The high bycatch rates, both within and beyond the U.S. EEZ have been deemed unsustainable for the pelagic population, with concerns heightened by potential underreporting in U.S. fisheries and a lack of observer coverage on foreign vessels.

 MHI insular false killer whales are also vulnerable to interactions with a variety of commercial and recreational fisheries in their nearshore habitat. Few deaths or serious injuries resulting from fisheries interactions have been documented in this population, but accurate estimates of the number of fisheries interactions are not available because the inshore fisheries are not monitored. However, recent analyses of fishery-related wounds or scars along the mouth-line or on the dorsal fin suggest that the frequency of fishery interactions in the MHI insular population occurs at an even higher rate than experienced by the pelagic population.  

The Northwestern Hawaiian Islands false killer whale population often resides within the Papahānaumokuākea Marine National Monument, where restricted fishing activity has likely limited recent interactions with fisheries since the monument’s establishment. 

Current Conservation Efforts

Hawaiian Pelagic False Killer Whale Population

The FKWTRT continues to work to identify and implement effective mitigation measures to reduce the mortality and serious injury of the pelagic population in longline fisheries. The FKWTRP includes measures requiring that longline fishers use ‘weak circle hooks’ and ‘strong branch lines’, as well as certain handling techniques when a false killer whale is hooked. This configuration is designed to enable targeted tuna and swordfish to be caught, but allow the heavier, stronger false killer whales to straighten the hooks and escape. However, success has been mixed, with some whales escaping but others left with embedded hooks and trailing line, posing serious injury risks. Compliance with proper handling techniques, such as applying tension until the hook straightens, has been inconsistent on the 20% of observed trips, and may be poorer on unobserved trips. The FKWTRT is addressing these issues, looking for ways to encourage the use of stronger branch lines, gathering more information on what happens when a whale is hooked, and improving the release methods used by longline boat crews. In addition, the FKWTRT is considering the use of electronic monitoring to increase the proportion of the fleet that is monitored.

The FKWTRP also includes a contingency measure that would close an area south of the MHI (southern exclusion zone – SEZ) for the remainder of the calendar year if a certain threshold is met for pelagic population bycatch levels within the U.S. For the first time, in 2018, the threshold at the time of two mortalities or serious injuries was met and exceeded when four whales were seriously injured or killed within the EEZ within one year. As a result, the fishery was excluded from the SEZ from July 24th through the end of 2018. In January 2019, a false killer whale was killed and another seriously injured within the EEZ, again triggering the closure of the SEZ. The SEZ could not reopen until specific criteria were met, such as no further injuries for two years or mortality rates not exceeding the population’s potential biological removal (PBR) level. In 2020, a larger population estimate was published, and NMFS reopened the SEZ after the mortality rate fell below the new PBR (which is based on population size). This also led to an increase in the threshold for closing the SEZ, from two to four mortalities and serious injuries. In 2021, three mortalities and serious injuries occurred within the EEZ between mid-January and mid-April, and then a fourth interaction occurred in November. However, the determination that the interaction resulted in a serious injury was not made until after the end of the year, and consequently the SEZ was not closed, which made it clear that the closure policy needs to be revised.

In late 2022 and early 2023, the FKWTRT met to recommend new management/mitigation measures that would finally to reduce mortality and serious injury to levels less than the population’s PBR. However, the team could not reach consensus, which left NMFS with the responsibility for amending the FKWTRP using the ideas generated by the team and the recommendations from factions within the team. Proposed mitigation measures included reducing the amount of fishing taking place (effort reductions) and further modifications to the gear and fishing practices. NMFS is expected to publish proposed amendments to the FKWTRP in the next year.

Main Hawaiian Island Insular False Killer Whale Population

After designating the MHI insular population as endangered under the ESA in 2012, NMFS announced its intention to prepare a recovery plan to guide future research and management-recovery activities.  In October 2020, NMFS released a draft recovery plan and implementation strategy for public review and comment. Commission comments, submitted in December 2020, and NMFS published the final recovery and implementation plans in November 2021.

In November 2017, NMFS published a proposal for designating critical habitat under the ESA. The Commission recommended that NMFS “undertake or support research needed to refine that designation by determining if there are specific areas that are essential to enabling the population to sustain itself in a healthy and productive state, to recover to the point where listing under the ESA is no longer warranted and, ultimately to reach its carrying capacity level.” The final Critical Habitat designation, which was announced in July 2018, excluded three additional areas from the designation due to national security concerns, and an assessment that the areas are used only infrequently by false killer whales.

Species Status

First recognized in the Gulf of Mexico in 1965, Rice’s whales were assumed to be a part of the broadly distributed Bryde’s whale complex which occurs in tropical and subtropical waters of the Atlantic, Pacific, and Indian Oceans. After many other large whale species became depleted by commercial whaling, whalers began targeting Bryde’s whales in the 1900’s. Between 1911 and 1987, over 30,000 Bryde’s whales were killed worldwide by commercial whalers.

Genetic analyses recently determined that the Gulf of Mexico population is distinct from other Bryde’s whale populations. Based on genetics analyses and new morphological information, scientists have recognized the Gulf of Mexico Bryde’s whale as a new species, with the name Rice’s whale (Balaenoptera ricei). The common name and species name honors the renowned cetologist Dale W. Rice, who, in 1965, was the first researcher to recognize that Bryde’s whales are present in the Gulf of Mexico. The name ‘Gulf of Mexico whale‘ has also been suggested for this species.

The population size of the Rice’s whale is estimated to number only 51 individuals, and are one of the most critically endangered large whales in the world. They occur primarily in the northeastern Gulf of Mexico, along the shelf break in waters between 100 and 400 meters deep within the De Soto Canyon region off the Florida Panhandle, but visual and acoustic surveys have also confirmed their presence in the western Gulf, recently as far south as Mexico. Spatial density models suggest that suitable habitat is available for Rice’s whales in the entire Gulf of Mexico in the 100 to 400m depth range.

Rice’s whales are threatened by vessel strikes, acoustic disturbance from seismic airguns and other oil and gas-related activities, military training activities, vessel noise, entanglement in commercial fishing and aquaculture gear, marine debris, and pollution from agricultural runoff and oil spills in the Gulf of Mexico.

A petition to list the northern Gulf of Mexico stock of Bryde’s whale (i.e., Rice’s whale) as endangered under the  Endangered Species Act (ESA) was submitted to the National Marine Fisheries Service (NMFS) in 2014. NMFS subsequently initiated a status review of Bryde’s whales under the ESA, which was finalized in December 2016. The status review determined that the Gulf of Mexico Bryde’s whale is taxonomically a subspecies of the Bryde’s whale complex, thus meeting the ESA’s definition of a species. Based on the Gulf of Mexico Bryde’s whale’s small population (likely fewer than 100 individuals), its life history characteristics, its extremely limited distribution, and its vulnerability to existing threats, NMFS determined that the Gulf of Mexico Bryde’s whale was in danger of extinction throughout all of its range. In April 2019, NMFS listed the Gulf of Mexico Bryde’s whale as endangered.

NMFS published a final rule establishing the name change from Bryde’s whale (Gulf of Mexico subspecies) to Rice’s whale under the ESA in August 2021. The immediate next steps are the development of a recovery plan and designation of critical habitat under the ESA. In the interim, NMFS has prepared a guidance document to direct recovery efforts for the Rice’s whale until a recovery plan has been developed.

In the Fall of 2021, NMFS held a series of recovery planning workshops to seek input from experts and stakeholders on (1) approaches for recovery planning that address the challenges relevant to the recovery of the listed species in its current and foreseeable environment; (2) development of possible recovery criteria that would indicate when the species should be considered for delisting; and (3) development of suggested recovery actions to reduce and/or ameliorate the threats to these listed whales. A summary of the recovery planning workshops is now available.

In July 2023, NMFS proposed to designate critical habitat for Rice’s whale in the northern Gulf of Mexico. NMFS identified the following feature as essential to the conservation of Rice’s whale: Gulf of Mexico continental shelf and slope waters  from 100 m to 400 m deep that support individual growth, reproduction, and development, social behavior, and overall population growth. This feature has the following attributes that support Rice’s whales’ ability to forage, develop, communicate, reproduce, rear calves, and migrate:

• Sufficient density, quality, abundance, and accessibility of small demersal and vertically migrating prey species, including scombriformes, stomiiformes, myctophiformes, and myopsida;
• Marine water with (i) elevated productivity, (ii) bottom temperatures of 10–19 degrees Celsius, and (iii) levels of pollutants that do not preclude or inhibit any demographic function; and
• Sufficiently quiet conditions for normal use and occupancy, including intraspecific communication, navigation, and detection of prey, predators, and other threats.

Comments on the proposed critical habitat designation were due to NMFS by October 6, 2023. NMFS is currently reviewing comments before issuing a final critical habitat designation.

What the Commission Is Doing

The Marine Mammal Commission is working with NMFS and other partners in the Gulf of Mexico to expand research and monitoring efforts for all marine mammals.

The Commission recently partnered with the Smithsonian Institution and NMFS to raise awareness regarding Rice’s whales. A special symposium focused on Rice’s Whales and other endangered large whales, “Whales on the Brink“, was convened on November 16, 2023, at the Smithsonian National Museum of Natural History, as part of the 50th Anniversary Celebration of the Endangered Species Act. The symposium followed the Commission’s 2023 Annual Meeting, which was held November 14-15, 2023 at the Navy Memorial Visitor’s Center in Washington, D.C.

The Commission regularly contributes guidance and input to NMFS on its deployment  of acoustic recorders around the Gulf of Mexico, including in Mexican waters, to detect the presence and seasonal distribution of Rice’s whales and other offshore marine mammals and to understand the various sources and sound levels associated with human activities in the Gulf. More about passive acoustic research being conducted by NMFS and its partners in the Gulf of Mexico, including the Long-Term Investigations into Soundscapes, Trends, Ecology, and Noise in the Gulf of Mexico (LISTEN GoMex) project, can be found on the NMFS Southeast Fisheries Science Center’s Passive Acoustic Research webpage.

The Commission submitted comments in July 2023 in support of a petition to establish vessel speed and other vessel-related measures to protect Rice’s whales. However, NMFS denied the petition in October 2023, citing the need to focus on other high priority conservation actions including finalizing critical habitat for the species, conducting additional vessel risk assessments, and developing a recovery plan for the species. The Commission also submitted comments on NMFS’s proposal to designate critical habitat for Rice’s whales. A decision on that action is still pending.

Commission staff recently served on a NMFS Steering Committee to convene experts and stakeholders in a series of workshops to identify recovery criteria and recovery actions for the Rice’s whale, as part of NMFS’s recovery planning efforts. Those workshops were held in October and November of 2021, and a summary of the workshops is now available.

Commission staff also served as one of two technical monitors on a RESTORE Act Science Program-funded project to evaluate Trophic Interactions and Habitat Requirements of Gulf of Mexico Rice’s Whales. The NMFS Southeast Fisheries Science Center, along with its partners from Florida International University and Scripps Institution of Ocenography, conducted the project from 2017 to 2021. The shipboard surveys conducted visual sightings, passive acoustic monitoring, tagging, prey characterization from echosounders and net tows, and the collection of biological samples. The field work focused on habitat characterization in the eastern Gulf of Mexico. Outcomes included an improved understanding of population status, identification of habitat features and characteristics, and a better understanding of the risk of exposure to human activities. A video presentation summarizing research from the RESTORE Science Program is available on the project website, along with additional information about the project.

In April 2015, the Commission held a meeting to identify high priority, overarching data needs and to identify potential funding sources and opportunities for expanding marine mammal research and monitoring in the Gulf. Presentations and a summary of the meeting are available here.

Commission Reports and Publications

Gulf of Mexico Marine Mammal Research and Monitoring Meeting Summary (Marine Mammal Commission 2015)

Assessing the Long-term Effects of the BP Deepwater Horizon Oil Spill on Marine Mammals in the Gulf of Mexico: A Statement of Research Needs (Marine Mammal Commission 2011)

Commission Letters

Learn More

Threats

The Rice’s whale is threatened by vessel strikes, acoustic disturbance from seismic airguns and other oil and gas-related activities, military activities, entanglement in fishing gear and aquaculture nets, marine debris, vessel noise, oil spills, and pollution.

Rice’s whale sightings and strandings are rare, but on 29 January 2019, a 38-foot male stranded in the Florida Everglades. A necropsy of the whale determined that it was underweight, and an examination of its stomach revealed a piece of hard plastic, approximately 5 cm by 7.5 cm in size. The plastic piece had sliced through part of the whale’s stomach, which likely contributed to its death. That whale’s skeleton is now at the Smithsonian Institution in Washington, D.C., and it represents the holotype for the new species.

Current Conservation Efforts

NMFS scientists are in the process of analyzing data recently collected on the abundance, distribution, diet, behavior, and habitat use of Rice’s whales in the Gulf of Mexico. The data, presented at a series of expert workshops convened in October and November 2021, are helping to identify recovery criteria and recovery actions for the Rice’s whale as part of NMFS’s recovery planning efforts to conserve and protect this stock from natural and human-caused threats. These data will also assist in efforts to designate critical habitat for the species under the ESA, and to help update Rice’s whale Biologically Important Areas.

The Future/Next Steps

Actions will be needed to ensure that energy development, fishing, aquaculture, shipping, and other potentially harmful activities are prevented from expanding into Rice’s whale core habitat areas. NMFS is conducting extensive passive acoustic monitoring throughout the Gulf of Mexico to determine, among other objectives, the extent to which Rice’s whales occur in areas beyond the core habitat identified in the eastern Gulf. Continued visual and acoustic surveys, biological sampling, and trophic studies are needed to understand Rice’s whale foraging and diving behavior, prey preferences and availability, and the potential effects of climate change on this endangered species.

Species Status

Abundance and Trends

The most recent state-wide abundance estimate is 9,790 manatees. That includes approximately 4,630 manatees on the west coast of Florida and 5,160 manatees on the east coast. Those estimates are based on aerial surveys that were conducted in 2021 and 2022 and represent an increase from the last state-wide abundance estimate of 8,810, despite the unusual mortality event that was declared on the east coast in 2021.

Florida manatees have been divided into four regional management units: the Atlantic Coast, Upper St. Johns River, Northwest, and Southwest. The 2021 estimate on the west coast is similar to the estimate from 2015, however, estimates of individual management units reflect a potential shift in distribution between surveys. On the east coast, the Upper St. Johns River estimates were similar in 2016 and 2022, while the abundance of the Atlantic coast management unit unexpectedly increased during that time.

Distribution

The Florida manatee occurs only in coastal and inland waters of the southeastern United States, where it occupies the northern limit of the species’ range. Because prolonged exposure to water temperatures below 18°C (65°F) can be lethal to manatees, Florida manatees are confined largely to the southern two-thirds of the Florida Peninsula in winter. There they aggregate at warm-water springs and thermal outfalls from power plants, or remain along the edge of the Everglades at the southern tip of the state. As water temperatures rise in spring and summer, Florida manatees disperse throughout the state and into neighboring states.

Unusual Mortality Event: 2021 to present

Beginning in December 2020, a drastic uptick in carcasses and manatees requiring rescue was observed along the Atlantic coast of Florida. The increased number of stranded and dead manatees led FWS to declare an unusual mortality event (UME) in March 2021. Data released by FWC reflect a total of 1,100 manatee mortalities in 2021, nearly twice the number recorded in 2020. Agencies and partners from the Manatee Rescue and Rehabilitation Partnership also helped to rescue over 140 manatees statewide. In 2022, 800 mortalities and 106 manatee rescues were reported, and 518 mortalities and 146 rescues were reported in 2023.

While some of the mortalities were attributed to traditional causes of manatee deaths, including cold-stress and vessel collisions, the majority of recovered carcasses and rescued animals were emaciated. Researchers attribute the UME to starvation due to loss of seagrass, a primary food source of manatees, in Indian River Lagoon and other warm-water estuaries. Poor water quality in nearshore waters is believed to be a leading factor in the drastic reduction of seagrass beds.

In December 2021, several environmental organizations announced their intent to sue the Environmental Protection Agency (EPA) for failing to reinitiate consultation with FWS under the section 7 of the Endangered Species Act, specifically regarding inadequate water quality standards set by EPA that now adversely affect manatees. The Commission sent a letter to FWS in December 2021 recommending that FWS increase the capacity of rehabilitation and other facilities to house manatees, approve contingency sites for the temporary holding of manatees, incorporate expert findings into any supplemental feeding program, and continue to work closely with FWC and other members of the Manatee Rescue and Rehabilitation Partnership to obtain funding to increase facility capacity and to respond to and rehabilitate live-stranded manatees.

During the winter months, the impacts of seagrass loss are most severe, as manatees rely on warm-water sites to maintain their body temperature. FWS implemented a pilot supplemental feeding program in the winter of 2021-2022 in Indian River Lagoon to help sustain manatees through the cold months until warmer temperatures allowed animals to disperse and find alternative foraging sites. The supplemental feeding trial continued during the winter of 2022-2023, with over 399,000 pounds of romaine lettuce fed to the manatees at a single site. The supplemental feeding program was discontinued in the 2023/2024 winter season because seagrass monitoring efforts indicated adequate foraging resources.

FWS and FWC, in collaboration with the Manatee Rescue and Rehabilitation Partnership, continue to prioritize responding to and rehabilitating live animals in distress. In the long-term, efforts are underway to restore seagrass beds and natural warm-water habitat for manatees.

Endangered Species Act listing

The Florida manatee is a subspecies of the West Indian manatee, which, until 2017, was listed as endangered under the Endangered Species Act (ESA). However, in 2012, FWS received a petition requesting that all West Indian manatees, including Florida manatees and the second subspecies, Antillean manatees, be reclassified from endangered to threatened under the ESA. In April 2017, FWS officially downlisted the species. In its final rule, the agency cited that the West Indian manatee had met the downlisting criteria established in the 2001 Florida Manatee Recovery Plan and thus warranted reclassification from endangered to threatened.

Given the extreme number of manatee mortalities along the Atlantic coast since December 2020 and the declaration of the UME, there was growing support among Florida legislators for uplisting the species to endangered once again. FWS initiated a five-year status review of the West Indian manatee in July 2021. The purpose of the review was to assess ongoing conservation efforts and ensure that listed species are appropriately classified under the ESA. In November 2022, FWS received a petition requesting that the West Indian manatee be reclassified as endangered. FWS found that the petition presented substantial information and announced their intent to complete a status review in October 2023. FWS plans to issue a 12-month petition finding to address whether reclassification is warranted.

In 2024, FWS announced their intention to revise the critical habitat designation for the Florida manatee, which was originally designated in 1976. They also plan to designate critical habitat for the Antillean manatee in Puerto Rico.

More Information

Manatees and Warm-Water Refuges

Manatee Harassment

What the Commission Is Doing

Legal Protection

In response to the 2016 proposed listing change of the West Indian Manatee by FWS, the Commission submitted a letter recommending that the two subspecies, the Florida manatee and the Antillean manatee, be considered separately. The Commission noted that despite an increase in the population size of Florida manatees, the growth of the population over the past 30 years has remained slow while manatee mortalities continue to reach record highs. The Commission also expressed concern with the loss of warm-water habitat due to eventual retirements of power plants over the next 30 to 40 years. This could threaten the future manatee population in Florida and reverse past recovery progress.

In addition, the Commission opposed changing the listing status for Antillean manatees, which, outside of Puerto Rico, continue to face considerable threats from habitat loss and degradation, hunting, fisheries bycatch, pollution, and human disturbance. The Sirenia Specialist Group of the International Union for the Conservation of Nature (IUCN) estimates that only about 2,500 mature Antillean manatees remain and projected that the subspecies would decline by 20 percent over the next two generations (40 years) in the absence of effective responses to current and projected anthropogenic threats.

FWS downlisted the West Indian manatee from endangered to threatened on 5 April 2017. However, the Commission remains committed to engaging with federal, state and local authorities to ensure adequate protections continue for the species and regularly participates in stakeholder meetings hosted by FWC. We continue to support an assessment of the potential harmful impact on manatees of a reduction in warm-water refuges through the retirement of power plants, as well as the effectiveness of boat speed restrictions.

Manatee Harassment

The Commission has also been concerned about the harassment of manatees by swimmers, divers, and kayakers at the Kings Bay warm-water refuge in the town of Crystal River, and particularly at Three Sisters Springs, the site’s largest spring. Parts of Kings Bay, including Three Sisters Spring, are managed as part of the FWS’s Crystal River National Wildlife Refuge. In August 2014, the Save the Manatee Club petitioned the FWS to close Three Sisters to human access during the winter manatee season. In response, the Commission wrote to the FWS in November 2014 noting the urgent need for further steps to reduce harassment in the spring and repeated past recommendations that the FWS adopt a no-touch policy and a minimum approach distance for swimmers.

In early 2015, the Commission conducted a site visit to Crystal River and met with involved federal, state, and local officials as well as local citizens and environmental group representatives to review manatee management efforts and plans at Crystal River. These matters were further considered during the Commission’s 2015 annual meeting. During the winter of 2014-15, Refuge staff temporarily closed Three Sisters Spring to human access on several occasions when high numbers of manatees were present in the spring. In 2017, FWS released an updated management plan for Three Sisters Spring, which includes guidelines to close the spring to public access when water temperatures in the region drop to 17 degrees Celsius.

Commission Reports and Publications

See Florida manatee sections in chapters on Species of Special Concern in past Annual Reports to Congress.

Laist, David W., Taylor, Cynthia, and Reynolds, John E. III. 2013. Winter Habitat Preferences for Florida Manatees and Vulnerability to Cold.

Laist, David W. and Shaw, Cameron. 2006. Preliminary Evidence that Boat Speed Restrictions Reduce Deaths of Florida Manatees.

Laist, David W. and Reynolds, John E. III. 2005. Influence of Power Plants and Other Warm-Water Refuges on Florida Manatees.

Laist, David W. and Reynolds, John E. III. 2005. Florida Manatees, Warm-Water Refuges, and an Uncertain Future.

Lowry, Lloyd, Laist, David W., and Taylor, Elizabeth. 2007. Endangered, Threatened, and Depleted Marine Mammals in U.S. Waters.

Taylor, Cynthia R. 2006. A Survey of Florida Springs to Determine Accessibility to Florida Manatees (Trichechus manatus latirostris): Developing a Sustainable Thermal Network.

Weber, Michael L. and Laist, David W. 2007. The Status of Protection Programs for Endangered, Threatened, and Depleted Marine Mammals in U.S. Waters.

Commission Letters

Learn More

Threats

Along the east coast of Florida, loss of seagrass, an important food source for manatees, may pose the greatest threat to the species and is considered the driving factor of the ongoing Unusual Mortality Event (UME). A 95% reduction of seagrass since 2011 has largely been attributed to increasing harmful algal blooms and reduced water quality.

Cold stress poses another threat to manatees and was likely a contributing factor to the increase in manatee mortalities in 2021. As manatees continue to lose warm-water habitat from the destruction of natural springs and the closure of power plants, full recovery of the species becomes more difficult.

In addition, collisions with boats are a frequent and increasing cause of human-related deaths, as propellers and boat hulls can inflict serious or mortal wounds. Vessel-related deaths reached a new peak in 2019, with 137 manatees stuck and killed by boats, which tops the previous record of 124 vessel-inflicted mortalities set in 2018.

Manatees can also be killed by neurotoxins associated with red tides that occur most often in southwest Florida. These toxins can be inhaled when they surface to breathe in affected areas, or ingested when they eat sea grass encrusted with tunicates that accumulate the toxins. In 2018, an unprecedented number of manatees died from a large and persistent red tide outbreak in southwest Florida. Harmful algal blooms are also thought to be a contributing factor to the loss of seagrass in estuaries along the Florida coasts.

Instances of manatee harassment are also a problem in areas of naturally occurring warm-water springs. When humans disturb manatees, it can alter their natural behaviors important for survival.

Current Conservation Efforts

On-the-ground manatee conservation efforts coordinated jointly by FWS and FWC are geared toward continuing to recover manatees and mitigating the impacts of ongoing threats.  Such activities include assessing the abundance of the Florida manatee population, tracking manatee movements through photo-identification and satellite-linked radio telemetry, developing a Warm-Water Habitat Action Plan to provide guidance for research and management of warm-water habitats into the future, including improving manatee access to natural warm-water systems, rescuing and rehabilitating distressed manatees, responding to and investigating manatee mortalities, responding to reports of manatee carcasses, enforcing site-specific boat speed zones, and strengthening management efforts to prevent harassment by divers at Crystal River.

Species Status

Hawaiian monk seals occur almost exclusively in the Hawaiian Archipelago, with occasional sightings at Johnston Atoll. Most monk seals are found at eight primary sites: Necker Island, Nihoa Island, French Frigate Shoals, Laysan Island, Lisianski Island, Pearl and Hermes Reef, Midway Atoll, and Kure Atoll) in the remote, largely uninhabited Northwestern Hawaiian Islands (NWHI). All of these islands are now part of the Papahānaumokuākea Marine National Monument. Along with the Mediterranean monk seal, the Hawaiian species is one of only two remaining monk seal species. A third species, the Caribbean monk seal, went extinct in the 1950s.

Hawaiian monk seals were apparently extirpated from the main Hawaiian Islands (MHI) after Polynesians arrived. In the late 19th century, hunting in the NWHI pushed the species to the brink of extinction. Their numbers had rebounded substantially by the late 1950s. Subsequently the population declined again over the next 50 years to a level 70% lower than that of the late 1950s. This decline is not fully explained but was likely due to multiple factors, including variable oceanographic productivity and human disturbance. Fortunately, beginning in 2013 the total population of Hawaiian monk seals throughout their range began to increase (Baker et al 2016); a hopeful sign.

Threats to the species differ substantially between the NWHI (where they are now well protected from direct human interactions), and the MHI (where human-related impacts pose a significant and growing challenge) (Baker et al. 2011). In the NWHI, the major threats include entanglement in marine debris (particularly abandoned, lost, or otherwise discarded fishing gear (ALDFG)), starvation due to limited prey availability, shark predation, attacks on pups and females by aggressive adult male seals, and loss of pupping beaches due to rising sea levels. In the MHI, threats include fishery interactions (hookings and drowning in gillnets), toxoplasmosis (an infectious disease spread by cats), and intentional killing by people (Harting et al. 2021).

Learn more about Threats to Hawaiian Monk Seals.

The National Marine Fisheries Service (NMFS) is the lead agency responsible for monk seal research and management but it relies on partnerships with other agencies (e.g., the State of Hawaii Division of Aquatic Resources, U.S. Fish and Wildlife Service, Office of National Marine Sanctuaries, U.S. Coast Guard, and U.S. Navy), non-governmental groups (e.g., The Marine Mammal Center, Hawaii Marine Animal Response), and volunteers. NMFS adopted a recovery plan for Hawaiian monk seals in 1983 that was updated in 2007, and designated revised critical habitat in 2015.

In January 2016, NMFS released a new Hawaiian Islands Monk Seal Management Plan. The management plan is an important step toward successfully managing the MHI monk seal population, preparing to address emerging challenges, and fostering co-existence between humans and seals.

What the Commission Is Doing

We have participated in and attended meetings of the NMFS Hawaiian monk seal Recovery Team and have convened Hawaiian monk seal program reviews. We have also organized and supported workshops on priority research and management needs, and interventions such as vaccination and seal rehabilitation. We have also supported several monk seals research and conservation projects, the most recent being in FY20. Click here for more information.

Commission Reports and Publications

See Hawaiian Monk Seal sections in chapters on Species of Special Concern in past Annual Reports to Congress.

Lowry, Lloyd F., Laist, David W., Gilmartin, William G, and Antonelis, George A. 2011. Recovery of the Hawaiian monk seal: a review of conservation efforts, 1972 to 2010, and thoughts for the future

2002. Final Report: Workshop on Management of Hawaiian Monk Seals on Beaches in the Main Hawaiian Islands

Laist, D., Reynolds, J.E. III, Boness, D.J., Gale, N., Gerrodette, T., Lowry, L.F., and Ragen, T.J. 2002. Hawaii monk seal program review. A report to the Marine Mammal Commission, 33 pp

Reports prepared for the Marine Mammal Commission:

Lowry, Lloyd, Laist, David W., and Taylor, Elizabeth. 2007. Endangered, Threatened, and Depleted Marine Mammals in U.S. Waters – A Review of Species Classification Systems and Listed Species

Weber, Michael L. and Laist, David W. 2007. The Status of Protection Programs for Endangered, Threatened, and Depleted Marine Mammals in U.S. waters

Commission Letters

Learn More

Threats

Hawaiian monk seals face a variety of threats, including entanglement, prey limitation, shark predation, fishery interaction, intentional killing, loss of terrestrial habitat to rising sea levels, and disease. For more, visit our Threats to Hawaiian Monk Seals page.

Current Conservation Efforts

Enhancing Hawaiian monk seal recovery

Numerous recovery activities covered by a 2014  final programmatic environmental impact statement (PEIS) have been conducted, including pup translocations to improve survival, vaccination of wild monk seals to prevent or mitigate morbillivirus outbreaks, behavioral modification measures to enhance seal and public safety in the MHI, and the use of uncrewed aerial vehicles and new devices for studying seal movements and behavior. In 2020, NMFS obtained a 5-year permit, which allows continued research and conservation actions. Rehabilitation of seals in poor health is undertaken under the authority of NMFS’ Marine Mammal Health and Stranding Response Program. A previous study found that between 17 and 24 percent of all seals alive in 2012 had either benefited directly from conservation interventions or were descendants of seals that had benefited from such interventions between 1980 and 2012 (Harting et al. 2014).

Monk Seals in the Northwestern Hawaiian Islands

Each year, NMFS’ Pacific Islands Fisheries Science Center sends field teams to most of the major subpopulations in the NWHI to monitor seal abundance, survival, and pup production, and to mitigate factors likely to cause monk seal deaths. Teams disentangle seals, and a large-scale effort to remove marine debris from the seals’ habitat has reduced entanglement risk according to a recent paper published in Science. Other conservation measures include efforts to mitigate shark predation, reunite or foster unpaired pups with mothers, intervene to deter attacks by aggressive male seals on other seals, and move pups from sites with low survival to sites with higher survival. Regarding the latter, a study found that the survival of 19 weaned pups was greatly improved by moving them between subpopulations during 2012-2014 (Baker et al. 2020). NMFS also works with The Marine Mammal Center to treat seals for injuries, rehabilitate undernourished pups and juveniles and release them back to the wild.

Monk Seals in the Main Hawaiian Islands

Hawaiian monk seal numbers in the MHI have increased substantially from at least the early 1990s and continue to grow. While this has been a bright spot for the species status, it has raised many new and difficult research and management challenges, including the mitigation of interactions between seals and nearshore fisheries, beachgoers, swimmers, and divers, and disease transmission to Hawaiian monk seals from domestic and feral animals. For example, toxoplasmosis, a protozoal disease spread to monk seals and other native Hawaiian wildlife through the feces of cats has resulted in the documented deaths of monk seals (Barbieri et al 2016). There are hundreds of thousands of outdoor cats in the MHI.

Monk Seal Health Care Facilities

In 2014, The Marine Mammal Center of Sausalito, California, a non-profit veterinary research and rehabilitation center for injured and sick marine mammals, opened a new health care center for monk seals. Located on land owned by Natural Energy Laboratory Hawaii Authority in Kailua-Kona on the Island of Hawaii, the $3.2 million facility was funded entirely with private donations raised by the Center. Named Ke Kai Ola, meaning “healing sea,” the new monk seal hospital holding pools are able to provide long-term care for up to ten seals. The hospital also includes pens to hold seals in isolation when needed, a medical building with a laboratory and food preparation area, and an open-air education pavilion for visitors.

Since early July 2014, Ke Kai Ola operations have included nursing undernourished seals (primarily yearlings and pups) from the NWHI back to health before their transport and release back in the NWHI. The majority of seals rehabilitated thus far have been females, which could markedly increase the reproductive potential of the wild population.

Also in February 2014, a monk seal holding and care facility dedicated to monk seals became operational at NOAA’s new Inouye Research Center at Pearl Harbor on Oahu. This new facility includes four above ground pools, a complete necropsy laboratory, and a state-of-the-art veterinary laboratory for surgical and other veterinary procedures. The facility has been used to perform several monk seal dehookings and emergency surgeries, and to provide outpatient care for seals prior to their release back into the wild.

Species Status

Abundance and Trends

Whaling records suggest that North Pacific right whales occupied much of the northern Gulf of Alaska and the western side of the North Pacific from Kamchatka to the Sea of Japan prior to 1840 when commercial whaling began to target them. Within 10 years, the species had been severely depleted throughout its range and by 1900 was near extinction. While whalers turned to other species and other parts of the world, the International Convention for the Regulation of Whaling banned the commercial hunting of right whales in the North Pacific in 1937 and the North Pacific right whale population began a slow recovery. However, illegal Soviet whaling in the 1960s killed hundreds of whales, mostly in the northern Gulf of Alaska and Bering Sea, which again pushed the species towards extinction.

Although there is a great deal of uncertainty about the number of North Pacific right whales before commercial whaling and now, there were at a minimum 10,000, and presumably many more, whales distributed across the North Pacific before whaling. Today, there are likely no more than 500 whales.

Two populations of North Pacific right whales are recognized, a western population currently found offshore of Russia and Japan, and an eastern population currently found primarily in the eastern Bering Sea (U.S. waters). The most recent population estimate for the eastern population of whales, based on a 2010 study of whales observed on their summer-fall feeding grounds in the southeastern Bering Sea, was approximately 31 whales. In addition, a few individuals have been detected in the northern Gulf of Alaska south of Kodiak Island. Thus, the eastern population is considered by experts to number no more than 50 whales, making it one of the smallest known populations of large whales in the world. The small effective population size alone may put this population at extreme risk of extinction due to effects of inbreeding and the potential for random events to affect a large portion of the population.

The last population estimate for the western stock, based on survey data from 1989 to 1992, suggested approximately 900 individuals, with confidence intervals ranging from 404 to 2,108. However, no current reliable population estimates are available for the western stock.

Distribution

Very little is known about the movements, migration, or breeding and winter-spring calving/nursing grounds of the species. Commercial whaling data and limited survey and sightings data, suggest that they make north-south seasonal migrations, although the extent of those migrations and the winter destinations remain largely unknown.

The summer range of the eastern population includes the Gulf of Alaska and the Bering Sea, with the population primarily known from whales observed on summer-fall feeding grounds in the southeastern Bering Sea. A recent compilation of eastern North Pacific right whale sightings from 2006 to 2023 showed sightings primarily in the central North Pacific and Bering Sea. Sightings have ranged from as far south as central Baja California and Hawaii to the northern waters of the Bering Sea and the Sea of Okhotsk in the summer. Feeding during those sightings was observed throughout the range at different times of year, although concentrated in their Alaska feeding grounds. The study included sightings from the 2017 International Whaling Commission’s Pacific Ocean Whale and Ecosystem Research (IWC-POWER) cruise, which documented 12 unique right whales in the southeastern Bering Sea, over half of which were found east of the critical habitat designated in the 2000s. One individual may have been a juvenile, suggesting ongoing successful reproduction in this very small population. The 2023 IWC-POWER cruise had four additional North Pacific right whale sightings in the Gulf of Alaska.

Due to their small population size and limited sightings data, acoustic monitoring has been implemented in the Bering Sea and northern Gulf of Alaska to detect the presence of North Pacific right whales since the 2000s. Acoustic monitoring has shown that at least some right whales are present in the southeastern Bering Sea from May through early December and in the northern Bering Sea during summer, fall, and winter, which has been confirmed by at least one visual sighting.  Acoustic detections in eastern passes through the Aleutian Islands throughout the year may suggest that they were feeding or transiting in the area, possibly while moving or migrating between the Bering Sea and North Pacific.

The western population of North Pacific right whales feeds during the summer in the Sea of Okhotsk, around the Commander and Kuril Islands, and off the Kamchatka Peninsula, Russia, and possibly as far south as northern Japan. A 2021 publication documented 60 sightings on research cruises between 1994 and 2016, involving 83 individuals and 10 calves. The whales were concentrated in southern half of the Sea of Okhotsk, and far offshore southeast of the Kamchatka Peninsula. Whales from the western population have been sighted outside of their summer feeding grounds, with occasional reports of sightings in winter and spring, primarily along the coast of Japan and the western North Pacific.

What the Commission Is Doing

For years, the Marine Mammal Commission has been highlighting the North Pacific right whale as a species of extreme conservation concern. Our current efforts focus on three goals:

• Acquiring new evidence of the species’ occurrence outside the Bering Sea, especially evidence of migratory or other movements and the location(s) of wintering/calving grounds or important feeding grounds south of the Aleutians or in the northern Gulf of Alaska.
• Contributing to the understanding of human-based risk factors that can be mitigated, especially when and where the whales are likely at high risk of ship strike (e.g., crossing the northern Great Circle shipping route and in Unimak Pass in Alaska’s Aleutian Islands chain) or entanglement (e.g., southeastern Bering Sea).
• Identifying opportunities to increase funding for the conservation, research and recovery of the species.

In 2015, the Commission funded two grants to National Marine Fisheries Service’s (NMFS) Alaska Fisheries Science Center. One grant provided support to a ship-based, visual and passive acoustic survey of North Pacific right whales and other large whales in the Gulf of Alaska, and the second grant supported the analysis of passive acoustic data from permanent moorings in the Aleutian Islands and Bering Sea. In 2016, the Commission provided funding to support a NMFS Saildrone passive acoustic survey of portions of the Bering Sea; results were published in the report available here. Research is on-going on a project funded in 2021 using samples from archived museum research specimen’s baleen to explore migratory patterns and overwintering areas of North Pacific right whales.
In 2023, the Commission co-hosted a Whales on the Brink scientific symposium with NMFS and the Smithsonian National Museum of Natural History that featured the North Pacific right whale.

Commission Reports and Publications

To date, there are no Commission reports on the North Pacific right whale.

Commission Letters

Learn More

Threats

Due to the limited understanding of North Pacific right whale distribution, movements, biology, and ecology, the threats this species faces remain largely uncertain. However, there can be no doubt that its recovery, if not its survival, will depend on successful reproduction and recruitment into the adult population for decades into the future, and this requires that threats from human activities are identified and mitigated as quickly and as thoroughly as possible. The fate of the very small number of whales in the eastern population is primarily the responsibility of the U.S. federal government.

Vessel strikes can cause serious injury or death to North Pacific right whales. The closely related North Atlantic right whales are known to be particularly susceptible to vessel strikes, and North Pacific right whales are likely similarly at risk. North Pacific right whales presumably migrate, as do other right whales, between high-latitude foraging grounds and calving/nursing grounds in warmer, calmer, lower-latitude waters. This means that those whales using the feeding ground in the southeastern Bering Sea must cross, at least twice a year, the Great Circle shipping routes that link North America and Asia. The number of crossings could be greater given that they may move back and forth between feeding areas in the Bering Sea and Gulf of Alaska during the summer and fall. It is likely that the whales use Unimak Pass, the route through the Aleutians that is closest to the Bering Sea feeding ground. This pass, just 11 miles wide at its narrowest point, is used routinely by ships following the northern Great Circle route. In recent years, fishermen observed North Pacific right whales further north, near the Bering Strait, another narrow body of water, where they are at increased risk of being hit by ships. With the increase in global commercial shipping, combined with the ongoing loss of Arctic sea ice and general expansion of human activities in the Arctic, vessel traffic through this region can be expected to increase further.

North Pacific right whales are also susceptible to entanglement in fishing gear and marine debris, with gillnet and pot/trap fisheries in the Bering Sea and Gulf of Alaska posing a threat, particularly when these fisheries operate within the whales’ critical habitat. None of the right whales photographed in the southeastern Bering Sea had noticeable entanglement scars, but at least two others photographed in NMFS’s North Pacific right whale photo-identification catalog did. Additionally, in 2015, a young right whale was found entangled in aquaculture gear in South Korea, and in 2016, an entangled right whale was reported to have died while being disentangled in Volcano Bay, Hokkaido, Japan. Although entanglements of North Pacific right whales are rarely documented, entanglement in fishing gear is a major source of mortality for the North Atlantic right whales. Additionally, documented entanglements of Western Arctic bowhead whales in areas partially overlapping with the North Pacific right whale range suggest that this threat is present, despite limited documentation.

Climate change is likely to pose significant threats to the North Pacific right whale population, as their range within the North Pacific is already experiencing climate-related impacts, and their small population size exacerbates their vulnerability. The species’ dependence on large aggregations of zooplankton for feeding makes it particularly susceptible to changes in prey abundance and distribution, which could result from changes in oceanographic conditions. Declines in zooplankton availability could cause nutritional stress, reduced reproduction, lower survival rates, and disruptions to migration patterns.

NMFS’s recovery plan for the North Pacific right whale expands on these threats and identifies several others, including vessel noise and oil spills. We can only speculate on threats faced during the winter and spring when the whales’ whereabouts are largely a mystery.

Current Conservation Efforts

NMFS listed the North Pacific right whale as endangered under the Endangered Species Act (ESA) in 1970. In June 2013, NMFS finalized the recovery plan for the North Pacific right whale. The plan assessed the status of the species, described the threats it faces, and laid out the steps needed for the species to recover. The primary focus of the recovery plan is to obtain information on seasonal movements, habitat use, distribution, population size, and trends. In addition, the recovery plan highlights the need for better understanding of the threats affecting the species.

In 2008, NMFS designated two areas in Alaskan waters as critical habitat under the ESA for the North Pacific right whale. One is in the southeastern Bering Sea, where most of the eastern population spends the summer and fall.  The other is south of Kodiak Island in the Gulf of Alaska, where a few visual and acoustic observations have been recorded since 2000. In September 2023, NMFS announced a 12-month determination on a petition to revise the critical habitat designation based on updated scientific data.

In February 2024, NMFS completed a five-year status review that the ESA requires for listed species, concluding that the North Pacific right whale should retain its status as endangered. The review emphasized the critical need to further understand the species’ distribution and seasonal patterns, particularly for wintering areas, assessing overlap with and impacts from shipping and fishing activities, and continuing to identify emerging threats.