Marine Mammal Commission

Barataria Bay Bottlenose Dolphins

The Barataria Bay Estuarine System population of common bottlenose dolphins resides year-round in Barataria Bay, a large estuary in southern Louisiana. This population of bottlenose dolphins is genetically differentiated from other nearby bottlenose dolphin populations. Scientists estimate that the Barataria Bay dolphin population has declined by about 45 percent due to effects of exposure to oil from the 2010 Deepwater Horizon oil spill. Projections show the population is now threatened with extinction from operation of the Mid-Barataria Sediment Diversion Project, which will divert large amounts of fresh water into Barataria Bay.

Bottlenose dolphins form strong but fluid social bonds. Photo credit: NOAA

Species Status

Abundance and Trends

Barataria Bay is a shallow estuary in southern Louisiana, approximately 110 km long and 50 km wide. The southern portion of the bay is connected to the Gulf of Mexico by channels, or ‘passes’. The Barataria Bay population (stock) of bottlenose dolphins is genetically distinct from other dolphin populations occurring in Gulf of Mexico coastal waters, including other bay, sound, and estuary (BSE) dolphin populations. Among the 31 BSE bottlenose dolphin populations in the northern Gulf of Mexico, the Barataria Bay population is one of the largest with around 2,000 dolphins.

Oiled dolphin in Barataria Bay, Louisiana. Photo credit: Louisiana Department of Wildlife and Fisheries

The Barataria Bay dolphin population was heavily impacted by the 2010 Deepwater Horizon (DWH) oil spill, which released an estimated 168 million gallons of oil into the Gulf of Mexico over 87 days. The oil contaminated surface waters and nearshore habitats hundreds of miles away from the wellhead, including Barataria Bay.

At the time of the DWH spill, the abundance of Barataria Bay dolphins was unknown. However, analysis of data from photographic surveys done shortly after the spill indicated that there were over 3,000 dolphins in Barataria Bay at that time. Following the spill, many dolphins in Barataria Bay died, and many of those that survived could not successfully reproduce. Many of the dolphins that survived also had lung disease, impaired stress response, and other chronic diseases.  A population dynamics model predicted that, due to disease and failed reproduction, the Barataria Bay population would continue to decline for 10 years after the spill, dipping to a low point less than half of its pre-spill abundance before beginning a slow recovery. Analysis of subsequent photographic survey data suggests that the abundance of the Barataria Bay dolphin population was around 2,000 dolphins in 2019.

Threats to the Population

Ongoing threats to Barataria Bay dolphins include chronic disease and reproductive failure in dolphins that were exposed to oil from the DWH spill, and interactions with commercial and recreational fisheries. However, the greatest threat to the Barataria Bay dolphin population comes from building and operating the Mid-Barataria Sediment Diversion (MBSD) project in Plaquemines Parish, Louisiana. The MBSD project will divert water and sediment from the Mississippi River into the northern portion of Barataria Bay. The goal of the project is to rebuild marshland that has been eroding for decades due to oil and gas extraction, canal excavations, extreme weather events, subsidence, and sea level rise. However, operation of the MBSD will also significantly alter the dolphins’ estuarine habitat by adding large amounts of freshwater into the bay and thereby lowering its salinity.

Scientists modeled the habitat changes expected to happen with the MBSD project to determine the likely impacts to the Barataria Bay dolphin population.  They predict a catastrophic decline in the Barataria Bay dolphin population, with over 500 dolphins (one quarter of the population) dying within the first year of the MBSD operation. Dolphins that reside in the central and western portions of the bay are expected to be “functionally extinct” after just 10 years of the MBSD’s operation. After 50 years of operation, bottlenose dolphins across the entire bay will be almost entirely gone, with only a small number remaining near the bay’s barrier islands.

The Marine Mammal Protection Act (MMPA) generally prohibits taking marine mammals, absent authorization. It was doubtful that the project would meet the requirements to secure an authorization under the MMPA’s existing provisions, so, Congress passed legislation directing the Secretary of Commerce to waive the MMPA’s taking prohibition in spite of the predicted consequences of the MBSD project for the Barataria Bay dolphin population. Additional information about the MMPA waiver can be found on the “More” tab.

A Dolphin Intervention Plan was included in the Final Environmental Impact Statement as part of the MBSD project’s monitoring and adaptive management plan. However, the activities outlined in the plan are not focused on mitigation measures to avoid the project’s adverse impacts on the Barataria Bay dolphin population. Instead, they are focused on documenting and responding to dolphins that are injured, become ill, or are killed by the environmental changes in Barataria Bay that result from the MBSD project.

Given the large number of dolphins that will be exposed to extremely low salinity for prolonged periods of time, intervention (i.e., rescue and rehabilitation or relocation) will not be practical for more than a few animals. There is limited capacity to care for sick and distressed dolphins at marine mammal rehabilitation facilities in the northern Gulf of Mexico. Even if some dolphins are rescued and rehabilitated, the changes to their habitat would preclude successful reintroduction, forcing them to either remain in captivity or be relocated to another area, assuming another area with suitable habitat could be found. Rescue and rehabilitation efforts could save a small number of individual dolphins, but will not prevent the population from declining towards extinction.

What the Commission Is Doing

When the Louisiana Mid-Barataria Sediment Diversion (MBSD) project was first proposed as a Deepwater Horizon oil spill restoration activity in 2015, the Marine Mammal Commission identified threats to the Barataria Bay dolphin population posed by the project. The Commission has since recommended several alternatives and additional measures that could be taken to reduce impacts on dolphins while arguably allowing the project to meet its objectives.

The Commission provided detailed comments on its concerns and suggested alternative approaches to entities responsible for planning, reviewing, and approving the MBSD project, including the Louisiana Coastal Protection and Restoration Authority, the Louisiana Deepwater Horizon Trustee Implementation Group, NOAA’s National Marine Fisheries Service, the U.S. Army Corps of Engineers, and the RESTORE Act Gulf Coast Ecosystem Restoration Council. Despite the Commission’s recommendations, the project was approved without the inclusion of additional measures to reduce adverse impacts on dolphins. Construction of the project began in August 2023.

The Commission convened a webinar in March 2021 to provide information on the potential impacts of low-salinity exposure on dolphins and their prey, review the findings of the 2019 northern Gulf of Mexico bottlenose dolphin Unusual Mortality Event, identify data needs, and discuss options for mitigating and monitoring impacts to dolphins and their prey from future low-salinity exposure. For more information and to view the webinar, see ‘Effects of Low-Salinity Exposure on Bottlenose Dolphins.’

Commission Reports and Publications

For more information on the effects of low salinity water on bottlenose dolphin health and survival, please refer to the Commission’s March 2021 webinar on “Effects of Low-Salinity Exposure on Bottlenose Dolphins.”

Commission Letters

Letter Date Letter Description
October 18, 2022

Letter to U.S. Army Corps of Engineers and Deepwater Horizon Louisiana Trustee Implementation Group on its Final Environmental Impact Statement for the proposed Mid-Barataria Sediment Diversion project in Barataria Bay, Louisiana.

June 2, 2021

Letter to Deepwater Horizon Louisiana Trustee Implementation Group and U.S. Army Corps of Engineers on its Draft Phase II Restoration Plan #3.2 and Draft Environmental Impact Statement for the proposed Mid-Barataria Sediment Diversion project in Barataria Bay, Louisiana.

April 20, 2020

Letter to Deepwater Horizon Louisiana Trustee Implementation Group on its Draft Restoration Plan/Environmental Assessment #5: Living Coastal and Marine Resources – Marine Mammals and Oysters.

March 12, 2018

Letter to National Marine Fisheries Service on its issuance of a waiver of the Marine Mammal Protection Act’s taking moratorium for three wetland restoration projects in Louisiana, as directed by Public Law 115-123.

February 5, 2018

Letter to the Deepwater Horizon Louisiana Trustee Implementation Group on its Draft Strategic Restoration Plan and Environmental Assessment #3: Restoration of Wetlands, Coastal, and Nearshore Habitats in the Barataria Basin, Louisiana.

October 7, 2016

Letter to the Gulf Coast Ecosystem Restoration Council on its RESTORE Act Draft Comprehensive Plan Update 2016 for the Gulf of Mexico.

December 4, 2015

Letter to the Deepwater Horizon Natural Resource Damage Assessment Trustees on its Draft Programmatic Damage Assessment and Restoration Plan and Programmatic Environmental Impact Statement for the Gulf of Mexico.

September 28, 2015

Letter to the Gulf Coast Ecosystem Restoration Council on its Draft Funded Priorities List for Gulf of Mexico restoration activities under the RESTORE Act.

Learn More

Marine Mammal Take Authorization

The Marine Mammal Protect Act (MMPA) generally prohibits taking of marine mammals, that is “to harass, hunt, capture or kill, or attempt to harass, hunt, capture, or kill” them, absent authorization. The Act includes a variety of ways for securing such authorization to “take” marine mammals. One common way of securing authorization is through issuance of an incidental take authorization (under section 101(a)(5)) that authorizes the taking of small numbers of marine mammals incidental to an otherwise lawful activity. However, this type of authorization requires a finding that the taking will have no more than a negligible impact on the affected species and stocks, a finding that could not be made for the Barataria Bay dolphin population as the project was proposed.

Another type of generally available authorization is a waiver of the MMPA’s moratorium on taking marine mammals. A key finding for obtaining a waiver is that the taking will not disadvantage any species or stock (i.e., population) of marine mammals. Such a finding could not be made for the Barataria Bay dolphins, given the projected impacts of the freshwater diversion on the population. Hence, a waiver would not normally be available for the project. However, Congress passed legislation in 2018 {Section 20201 of Public Law 115-123, the Bipartisan Budget Act of 2018) directing the Secretary of Commerce to issue a waiver under the MMPA notwithstanding the otherwise applicable requirements. The waiver applies to three Louisiana wetland restoration projects-the Mid-Barataria Sediment Diversion, the Mid-Breton Sound Sediment Diversion, and the Calcasieu Ship Channel Salinity Control Measures project. The waiver required only that the State of Louisiana, in consultation with the Secretary, “upon issuance of [the] waiver,” take steps to:

  1. to the extent practicable and consistent with the purposes of the projects, minimize impacts on marine mammal species and population stocks; and
  2. monitor and evaluate the impacts of the projects on such species and population stocks.

In essence, Congress determined that completing these projects took precedence over the anticipated detrimental effects on dolphins. Louisiana is required to take steps to minimize these impacts, but only if doing so would be practicable to implement and would not undermine achieving the purposes of the project. The state of Louisiana and the Secretary of Commerce are responsible for determining whether mitigation measures are practicable, and whether such measures would undermine achieving the purposes of the project.

Research and Monitoring

Following the Deepwater Horizon oil spill, a number of studies were conducted to understand and quantify the effects on the bottlenose dolphins in Barataria Bay, as well as other dolphin and cetacean populations throughout the northern Gulf of Mexico. These studies, part of the Natural Resource Damage Assessment (NRDA) led by the National Oceanic and Atmospheric Administration with other co-trustees, included necropsies of dead stranded dolphins, capture-release health assessments of live dolphins, and photographic surveys to determine dolphin abundance, reproductive success, and survival rate. Collectively, the findings from the studies demonstrated that the Deepwater Horizon oil spill substantially impacted the health of Barataria Bay dolphins, leading to reproductive failure and increased mortality. Findings from the NRDA studies were summarized in the Deepwater Horizon Trustees’ Final Programmatic Damage Assessment and Restoration Plan. In addition, many of the studies were compiled and published in a Special Issue of the scientific journal Endangered Species Research: Effects of the Deepwater Horizon oil spill on protected marine species (Volume 33, 2018).

A group of dolphins swim in Barataria Bay. Photo credit: National Marine Mammal Foundation

The Gulf of Mexico Research Initiative (GoMRI) provided funding for continued studies of Barataria Bay dolphins that were exposed to the Deepwater Horizon oil spill. The GoMRI studies documented the persistence of chronic disease such as lung disease and impaired stress response. A model developed by the GoMRI researchers estimated that in the ten years following the Deepwater Horizon oil spill, the Barataria Bay dolphin population had declined by 45 percent. 

Additional Resources

NMFS 2021 Stock Assessment Report for the Barataria Bay Estuarine System Stock of Common Bottlenose Dolphin

Marine Mammal Commission 2021 Webinar on Effects of Low-Salinity Exposure on Bottlenose Dolphins

Louisiana Trustees Approve Funding for Mid-Barataria Sediment Diversion Project (Feb 2023)

Louisiana Trustee Implementation Group 2022 Final Phase II Restoration Plan #3.2: Mid-Barataria Sediment Diversion

NMFS 2018 Waiver of Requirements Under Sections 101(a) and 102(a) of the Marine Mammal Protection Act for the Mid-Barataria Sediment Diversion, the Mid-Breton Sound Sediment Diversion, and Calcasieu Ship Channel Salinity Control Measures Projects

Deepwater Horizon Trustee’s 2016 Final Programmatic Damage Assessment and Restoration Plan and Final Programmatic Environmental Impact Statement

Southern Resident Killer Whale

Killer whales are found in every ocean, but they are segmented into many small populations, at least two of which are likely separate species, that differ genetically, as well as in appearance, behavior, social structure, feeding strategies and vocalizations. The so-called “Resident” killer whales are fish eaters found along the coasts on both sides of the North Pacific. In the eastern North Pacific, there are three populations of Resident killer whales: Alaska Residents, Northern Residents, and Southern Residents. The Southern Residents, which comprise the smallest of the ‘resident’ populations, are found mostly off British Columbia, Washington and Oregon, but also travel to forage widely along the outer coast. Southern Residents are Chinook salmon specialists. They feed on Chinook year-round, and it is their primary prey in spring and summer when they occupy inland waters. During the fall and winter, when Southern Residents disperse widely, they add other salmon species (Coho in fall and chum in winter) and some demersal fishes to their diet (e.g., halibut and lingcod). Resident killer whales associate in stable matriarchal social units called ‘pods’. There are three pods for Southern Resident killer whales, called the J, K, and L pods.

Killer whales

Killer whales. (Holly Fearnbach, NOAA)

Species Status

Abundance and Trends

The total abundance for the Southern Resident killer whale population was officially revised in July 2021, standing at at only 74 whales. However, while the population still currently sits at 74 whales, there has been one birth and one whale presumed dead as of July 2023 . The first complete count of Southern Resident killer whales, which took place in 1974, found 71 whales. The population increased to its peak of 96-98 whales in the mid-1990’s following the cessation of killings and captures for marine parks, which stopped after the Marine Mammal Protection Act was enacted in 1972. The Southern Resident killer whales have produced a variable number offspring in recent years. From 2012 to 2014 there were just four births in total (average = 1.33 per year). Somewhat encouragingly, in 2015 seven calves were documented, which was the second largest, single-year number of births on record. Unfortunately, there have been a low number of calf births in recent years. From 2012 through 2020, there were 17 births (average= 1.9 per year), six of which have gone missing or died. During that same period, an additional 26 Southern Resident killer whales have gone missing or died.

A census of the Southern Resident killer whale population by the Center for Whale Research (CWR) shows the population trends through time (CWR, July 2019).


The three Southern Resident killer whale pods have different distributions off the West Coast and show different movements during the year, typically tied to the movements of the various runs of Chinook and other salmon. During the summer and fall, when all three pods have typically been present much of the time in Washington’s and British Columbia’s inland waters north and west of Puget Sound, K and L pods often travel to the outer coasts of Washington and Vancouver Island for a few days at a time. Their seasonal distribution has changed in recent years, with the whales spending significantly less time in inland waters in 2013, 2016, 2017 and 2018. In early fall, J pod regularly includes the waters of Puget Sound within their foraging range.  From late fall through spring, all three pods apparently spend the bulk of their time on the outer coast, ranging from San Francisco to Southeast Alaska. J and K pods, but rarely L pod, make short excursions to inland waters during this period. Although relatively little is known about their distribution during this time, recent evidence suggests that they are spending time near the mouths of major rivers and estuaries, presumably to take advantage of salmon runs during those seasons.

For more of the historical demographics and details on notable individuals visit the Southern Resident Killer Whale Population Details page.

Responding to a Continued Decline

The ongoing decline of the Southern Resident killer whale population over the last 20 years is most likely due to three distinct threats: decreased quantity and quality of prey, the presence of persistent organic pollutants, and disturbance from vessel presence and noise. In addition to federal conservation action by the National Marine Fisheries Service and Canada’s Department of Fisheries and Oceans, the state of Washington has dedicated considerable effort to reducing the threats faced by the whales. In 2018, Washington Governor Inslee created the Southern Resident Killer Whale Task Force to assist the state in identifying, prioritizing and supporting the implementation of an action plan for the recovery of Southern Resident killer whales. At all levels of government, stakeholders are working to reduce impediments to salmon recovery, decrease inputs of pollutants to the marine system, and manage vessel activity in their preferred habitat. Additional information on threats facing Southern Resident killer whales and their conservation can be found in the Learn More tab.

What the Commission Is Doing

The Marine Mammal Commission has long been concerned about the fate of Southern Resident killer whales, hosting the first workshop focusing on killer whales in Seattle in April 1975. The Commission has consulted with and assessed each of the steps taken by the National Marine Fisheries Service (NMFS) to promote the recovery of the population, and has provided recommendations to NMFS for improvements to their efforts. Some of the Commission’s recommendations have been to:

  • Make monitoring of population status a high priority recovery action;
  • Make monitoring and evaluation of the effectiveness of recovery actions a high priority;
  • Recognize natural sound characteristics as an essential feature of the critical habitat of Southern resident killer whales;
  • Implement a precautionary approach with regard to management of contaminants to prevent them from entering the Puget Sound environment;
  • Conduct research into habitat use during the winter by Southern Resident killer whales;
  • Develop regulatory provisions to establish vessel stand-by zones around Southern Resident killer whales beyond the 200-yard approach limit (e.g., beyond 400-600 yards) and limit the number of vessels that can be present between that boundary and the 200-yard approach limit at any one time;
  • Adopt a regulatory speed limit of either seven knots or, at a minimum, a “slow safe speed” requirement within 400 yards of killer whales;
  • Develop a monitoring plan to assess compliance with and effectiveness of vessel-approach regulations; and
  • Include implementation of a “no-go” zone off the west coast of San Juan Island.

In May 2018, the Commission held its annual meeting in Seattle, and Southern Resident killer whales were a primary focus of the meeting. Issues such as the population’s current status and trends, the factors affecting its health and viability, research being conducted on it, and conservation/management efforts being taken on its behalf, were on the agenda.

Click here for a report of what was discussed at the 2018 Annual Meeting regarding Southern Resident killer whales.

Commission Reports and Publications

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

Commission Letters

Letter Date Letter Description
December 31, 2019

Letter to NMFS regarding the scoping of potential regulations to protect Southern Resident killer whales from the impacts of vessel disturbance and sound in the inland marine waters of Washington State

December 18, 2019

Letter to NMFS regarding the proposed revision to critical habitat for the endangered Southern Resident killer whale distinct population segment 

October 29, 2018

Letter to Washington State Governor’s Southern Resident Orca Task Force commenting on its final Draft Recommendations

October 5, 2018

Letter to Washington State Governor’s Southern Resident Orca Task Force commenting on the Draft Report and Potential Recommendations

August 30, 2018

Letter to the National Ocean Service regarding a Draft Injury Assessment Plan for Upper Duwamish River, Seattle, Washington

March 31, 2017

Letter to NMFS regarding a petition to establish a regulatory zone along the southwest coast of San Juan Island to provide protection of a key feeding area for Sothern Resident Killer Whales

August 13, 2013

Letter to NMFS regarding the petition to include the captive Southern Resident killer whale known as “Lolita” in the Southern Resident killer whale endangered species listing

February 4, 2013

Letter to NMFS addressing a petition to delist Southern Resident killer whales

January 15, 2010

Letter to NMFS commenting on a proposed rule intended to reduce the effects of vessel traffic, including whale-watching activities, on killer whales in Washington’s inland waters

March 2, 2007

Letter to NMFS with recommendations concerning the proposed Southern Resident killer whale recovery plan

August 14, 2006

Letter to NMFS regarding the proposed critical habitat designation for Southern Resident killer whales

March 22, 2005

Letter to NMFS responding to the proposed listed of Southern Resident killer whales as endangered under the ESA

Learn More

Prey Limitation

Since the 1990s, as the abundance of Chinook salmon has declined, the whales have been moving about more to find the hundreds of thousands of salmon they require each year. Declines in the abundance of many stocks of Chinook salmon, their preferred prey, may be causing malnutrition, limiting growth, and complicating reproduction. Greater numbers of deaths and fewer birth have been correlated with lower availability of Chinook salmon. Several whales who have died recently were observed be in poor body condition, perhaps related to poor nutritional status.

Aerial photographs of J17, documenting a progression of the malnourished individual (SR3/NMFS NOAA Permit #19091). In extreme cases, the fat deposits on each side of the whale’s head are so low that it is described as ‘Peanut Head’, shown here.


Southern Residents spend much of their lives in inland waters near numerous sources of pollutants that accumulate in the fish they consume. Some researchers have argued that calf and juvenile deaths, delayed breeding, and now a skewed sex-ratio in calves, may be related to the effects of persistent organic pollutants (POPs) that have accumulated in the fatty tissues of the whales. Southern Resident killer whales have been shown to have high tissue levels of pollutants that are associated with lowered disease resistance and/or decreased reproduction in marine mammals. If a whale encounters a period of low prey abundance, it will mobilize energy in its fat reserves, thus releasing those pollutants into its blood stream, which can degrade the whale’s health, affect its reproductive potential and even lead to death. A recent study found that between 2008 and 2014 over 2/3 of detectable Southern Resident killer whale pregnancies were unsuccessful. The authors of that study concluded that limited availability of Chinook salmon was the primary cause, while the transfer of POPs from the mother to the calf through breast milk may have be a contributing factor to the poor calf and juvenile survival rate.


Vessels are prevalent in the Salish Sea, traveling to and from Vancouver, Seattle, Tacoma, and many smaller ports. Vessel traffic is predicted to increase with future development projects and greater numbers of oil tankers passing through Southern Resident killer critical habitat in the San Juan Islands. Vessels both large (such as cargo ships, container ships, and ferries) and small (such as commercial whale-watching boats, recreational fishing vessels, and other recreational/private vessels) can cause disturbance based on their physical presence in proximity to the whales. In addition, sound emitted from certain vessels may exacerbate that disturbance by masking communications among the whales. Smaller vessels, especially the commercial and private vessels engaged in whale watching, emit sounds within the hearing range where whales are more sensitive and are likely to be in closer proximity to the whales.

Research has shown that Southern Resident killer whales exhibit a variety of responses to the presence of vessels, including altering their behavior (vessel avoidance and attraction, reduced surface time and longer dives, increased time spent traveling, increased respiration rate and swimming speed, reduced foraging, disruption and interruption of foraging or traveling) and modulating their vocalizations (increased loudness). In addition, the presence of vessels may contribute to an increase in stress hormones when prey is limited. The various studies also have concluded that the physical presence of the vessels cannot be separated from the sound that they generate, making it difficult to determine whether the vessels themselves or the sound that they emit disturb the whales.

Current Conservation Efforts

Recent modeling suggests that a robust population recovery can be achieved with an increase in the abundance and availability of their preferred prey, Chinook salmon, and a reduction in the amount of disturbance and noise from boats and ships. Both of these remedies are possible within a few years, while reducing contaminants, which will be much more difficult to achieve in time to arrest the population decline. Consistent with these findings, NMFS is undertaking a suite of management and research activities designed to enhance the recovery of the population. Those activities include:

  • Implementation of vessel regulations and guidelines
  • Support of salmon restoration efforts
  • Oil spill response preparation
  • Studies to improve understanding of the impacts of anthropogenic sound
  • Public outreach and education
  • Studying year-round movements and diets
  • Conducting stranding investigations and health assessments
  • Monitoring the population trend

In addition to efforts being undertaken by NMFS, the state of Washington is implementing its own conservation efforts under the leadership of Governor Jay Inslee. In 2018, Governor Inslee issued an executive order that established the Southern Resident killer whale Task Force to assist the state in identifying, prioritizing and supporting the implementation of an action plan for the recovery of Southern Resident killer whales. Along with other government agencies and a wide range of public stakeholders, the Commission provided the Task Force with feedback on its draft report and recommendations. The Task Force released its final report with recommendations in mid-November, and those recommendations are reflected in the Governor’s budget and policy priorities. The Task Force made recommendations designed to increase the availability of Chinook salmon to Southern Resident killer whales, and decrease the risk to the whales from vessels, noise and contaminants.

For more information on NMFS and Washington state conservation efforts visit our Southern Resident Killer Whale Conservation and Management page

Additional Resources

General Information

NMFS Killer Whale page

NMFS Killer Whale Research page

Center for Whale Research

Governor of Washington’s Orca Recovery page

Selected Peer-Reviewed Publications

Potential benefits of vessel slowdowns on endangered Southern Resident killer whales. Ruth Joy et al. 2019. Frontiers in Marine Science

Unprecedented biennial pattern of birth and mortality in an endangered apex predator, the southern resident killer whale, in the eastern North Pacific Ocean. Gregory T Ruggerone et al. 2019. Marine Ecology Progress Series 608:291-296

Noise exposure from commercial shipping for the southern resident killer whale population. Simone Cominelli et al. 2018. Marine Pollution Bulletin 136:177-200

Using aerial photogrammetry to detect changes in body condition of endangered southern resident killer whales. Holly Fearnbach et al. 2018. Endangered Species Research 35:175.180

Inbreeding in an endangered killer whale population. Michael J. Ford et al. 2018. Animal Conservation 21(5):423-432

Evaluating anthropogenic threats to endangered killer whales to inform effective recovery plans. Robert C. Lacy et al. 2017. Scientific Reports 7:14119, DOI: 10.1038/s41598-017-14471-0

Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca). Samuel K. Wasser et al. 2017. PLoS ONE 12(6): e0179824.

Exposure to a mixture of toxic chemicals: Implications for the health of endangered Southern Resident killer whales. Teresa M. Mongillo, et al. 2016. NOAA Technical Memorandum NMFS-NWFSC-135, 107 pp

Social network correlates of food availability in an endangered population of killer whales, Orcinus orca. Emma A. Foster et al. 2012. Animal Behaviour 83(3): 731-736

Size and long-term growth trends of Endangered fish-eating killer whales. Holly Fearnbach et al. 2011. Endangered Species Research 13(3): 173-180

The relationship between vessel traffic and noise levels received by killer whales (Orcinus orca). Juliana Houghton et al. 2015. PLoS ONE: doi:10.1371

Linking killer whale survival and prey abundance: food limitation in the oceans’ apex predator? John K.B. Ford et al. 2010. Biology Letters 6(1):139-142

Effects of age, sex and reproductive status on persistent organic pollutant concentrations in “Southern Resident” killer whales. Margaret M. Krahn et al. 2009. Marine Pollution Bulletin 58:1522-1529

Vessel traffic disrupts the foraging behavior of southern resident killer whales Orcinus orca. David Lusseau et al. 2009. Endangered Species Research 6:211-221

Quantifying the effects of prey abundance on killer whale reproduction. Erik J. Ward et al. 2009. Journal of Applied Ecology 46(3): 632-640

The social dynamics of southern resident killer whales and conservation implications for this endangered population. Kim M. Parsons et al. 2009. Animal Behaviour 77(4): 963-971

Relevant Documents

Southern Resident Orca Task Force, Draft Year 2 Report, October 2019

Southern Resident Orca Task Force, Report and Recommendations, November 16, 2018.

2017 Stock Assessment Report for Southern Resident Killer Whales

Review of Recent Research on Southern Resident Killer Whales (SRKW) to Detect Evidence of Poor Body Condition in the Population. Matkin, CO, MJ Moore, and FMD Gulland. 2017. Independent Science Panel Report to the SeaDoc Society. 3 pp. +Appendices. DOI 10.1575/1912/8803

2017 Action Plan for the Northern and Southern Resident Killer Whale (Orcinus orca) in Canada [Final Version]. Fisheries and Oceans Canada.

Southern Resident Killer Whales (Orcinus orca). 5-Year Review: Summary and Evaluation. National Marine Fisheries Service, West Coast Region. December 2016. 72 pp

2016 Species in the Spotlight. Priority Actions: 2016-2020, Southern Resident Killer Whale DPS Orcinus orca

2015 Species in the Spotlight Campaign identifying Southern Resident killer whales among the species at most at risk of extinction

2015 Ruling to extend Southern Resident killer whale endangered species protections to captive members of the population, and specifically to the captive female known as “Lolita”

2015 Report on 10 years of Southern Resident Killer Whale Research

2011 Vessel Regulations in Washington State for Southern Residents

2008 Recovery Plan for Southern Resident Killer Whales

2006 Critical Habitat Designation for Southern Residents

Pacific Walrus

The Pacific walrus is a subspecies of walrus (Odobenus rosmarus) found in the Bering, Chukchi, Laptev and East Siberian Seas. The reliance of walruses on sea ice for resting during the summer foraging period makes them vulnerable to changes in climate and the associated loss of sea ice.

All walruses have tusks, but tusks tend to be longer and thicker in males than females.

Species Status

Abundance and Trends

The first documented aerial survey of Pacific walruses was conducted jointly by the United States and the former Soviet Union in 1975, after the enactment of the Marine Mammal Protection Act (MMPA) in 1972. This survey provided an estimate of about 246,000 animals and subsequent surveys suggested a population decrease to about 201,000 by 1990. The most recent aerial survey, conducted in 2006 by the U.S. Fish and Wildlife Service (FWS), estimated the walrus population to be about 129,000 but with a large confidence interval of 55,000-550,000 animals. The 2006 survey did not cover the entire walrus range and therefore is likely to be an underestimate of the total population size.

Although the estimates between 1975 and 2006 suggest that the population has declined, the differences in methods and geographic coverage between the surveys make it impossible to determine population trends over time. Surveying walruses is difficult because during the spring, when the surveys are conducted, walruses are distributed widely across the Bering Sea pack ice and spend a significant portion of their time in the water. Adverse weather conditions in this region further hinder survey efforts.

Faced with these difficulties, FWS began testing new population estimation methods in 2012 using a mark-recapture approach, which provided a preliminary estimate of 283,000 animals in 2014 with another large confidence interval. The final study, published in 2022, analyzed data from 2013 to 2017 and estimated Pacific walrus abundance to be approximately 257,000 animals. Pacific walrus abundance is expected to decline as sea ice loss continues, although the magnitude of the predicted decline is unknown. Overall, walrus population growth rates tend to be slow, with mature females producing a calf on average every 3 years. However, natural mortality also tends to be low and walruses can be long-lived. Their only natural predators include polar bears and killer whales. They are also harvested for subsistence purposes by Alaska Natives, as authorized under the MMPA.


Pacific walruses range across the continental shelf waters of the northern Bering Sea and Chukchi Sea. Because they rely on broken ice habitat and coastal haulouts to access feeding areas on the ocean floor, their distribution varies in response to seasonal and annual changes in sea ice cover. In the winter, breeding aggregations form in the Bering Sea pack ice where there is access to open water. As the sea ice retreats in the spring, most walruses migrate north to feeding areas in the Chukchi Sea. In years with low sea ice, walruses may migrate into the Beaufort and East Siberian Seas. Those walruses are often associated with loose pack ice, but will use coastal haulouts once the sea ice retreats north of the continental shelf waters. Most adult male walruses, as well as some adult females and juveniles, remain in the Bering Sea and use coastal haulouts throughout the summer feeding season. As sea ice begins to form again in the fall, walruses that migrated north for the summer typically return south.

Seasonal distribution, breeding areas, and coastal haulouts of Pacific walruses. (Smith 2010; FWS 2011)

Pacific Walruses and Climate Change

Walruses rest on sea ice when it is available, but will use coastal haulouts when sea ice is not present. Since 2007, summer sea ice in the Chukchi Sea has retreated offshore to areas too deep for walruses to reach the ocean floor to feed. As a result, many walruses have to travel farther to reach their foraging grounds and are now using coastal haulouts to rest between foraging trips. Thousands of walruses have been observed on land in the U.S. and Russia during late summer. Some of the coastal haulouts are located near communities where human activity and the presence of predators, like polar bears, may disturb walruses. When large groups of walruses are disturbed, subsequent stampedes can cause the trampling and death of many walruses. Stampedes not only result in trampled young animals, but can separate mothers and calves and cause injury and death of weak animals recovering from prolonged foraging trips. Additionally, traveling farther to reach foraging grounds will increase walrus energetic demands. It is unknown whether this may affect body condition, reproduction rates, and survival.

To gain a better understanding of walrus distribution, abundance, and the formation of large coastal haulouts in response to climate change, USGS has developed methods to monitor walruses using satellite imagery. Satellite imagery allows scientists to easily monitor extremely remote locations, and recent methods using synthetic aperture radar, which relies on radar signals bouncing off Earth’s surface, can capture images of haulouts regardless of weather or time of day. Satellite imagery is being used to detect coastal haulouts and methods to estimate walrus abundance with improved precision and to detect carcasses are under development.

What the Commission Is Doing

The Marine Mammal Commission maintains close contact with Alaska Native communities that rely on walruses as a source of subsistence. In February 2016, the Commission led a series of listening sessions in Alaska to learn more about the challenges that Alaska Natives are facing as a result of climate change. Participants in those sessions noted that walruses are becoming more difficult to access due to adverse ice and weather conditions.

Commission Reports and Publications

For more information on the Pacific walrus, see the Commission’s 2010-2011 Annual report (pages 178-182) and 2012 Annual Report (pages 55-59).

Commission Letters

Letter Date Letter Description
May 8, 2023

Draft 2022 Stock Assessment Reports

June 30, 2021

Application from Alaska Oil and Gas Association seeking authorization to take polar bears and walruses incidental to oil and gas operations in the Beaufort Sea, Alaska.

November 10, 2020

Notice of plans to conduct Alaskan Arctic Coast Port Access Route Study

June 13, 2017

Application from Quintillion Subsea Operations, LLC, to take walruses and polar bears incidental to conducting subsea cable-laying activities in the Bering, Chukchi and Beaufort Seas, Alaska.

July 7, 2016

Application from Alaska Oil and Gas Association seeking authorization to take polar bears and walruses incidental to oil and gas operations in the Beaufort Sea, Alaska

October 30, 2015

Amendments to the Appendices to the Convention on International Trade in Endangered Species of Wild Fauna and Flora for the Seventeenth regular meeting of the Conference of Parties.

July 17, 2013

Draft stock assessment reports for Pacific walrus and three stocks of Northern sea otters in Alaska

February 8, 2013

Application from the Alaska Oil and Gas Association for authorization to take polar bears and Pacific walruses incidental to oil and gas exploration activities in the Chukchi Sea and the adjacent western coast of Alaska

June 20, 2012

Listing of the polar bear, walrus, and narwhal on CITES Appendices

January 3, 2011

Listing the Pacific walrus as threatened under the Endangered Species Act

Learn More


The greatest threat to the Pacific walrus is climate change. As the pack ice that they rely on during the summer foraging season in the Chukchi Sea diminishes, walruses are increasingly forced to seek refuge at land-based haul out sites. Over the last decade, large aggregations of animals have been observed at haulout sites near Point Lay, Alaska. Such aggregations may be dangerous for calves and juveniles if disturbance by humans or other factors cause adults to stampede. Local communities have taken important measures, in collaboration with FWS, to limit the potential for such disturbance.

Reduction of sea ice and ocean warming are also expected to increase the frequency, intensity, and geographic range of harmful algal blooms (HABs) in the Arctic. Two of the most common HAB toxins on the west coast of North America are domoic acid and saxitoxin. Those toxins, associated with amnesic and paralytic shellfish poisoning in humans, can also cause illness and death in marine mammals. A 2016 study reported that out of 13 Alaskan marine mammal species, Pacific walruses contained the highest concentrations of both domoic acid and saxitoxin. No abnormal behaviors of the sampled walruses were reported, so it is unlikely that toxicological effects have occurred; however, toxin concentrations were in the range known to cause illness and/or death in California sea lions, humpback whales, and humans, and two walruses sampled in 2019 had saxitoxin concentrations near the seafood safety regulatory limit. There is concern that increased exposure to biotoxins as sea ice continues to melt may increase the risk to both marine mammals and the people that rely on them for subsistence.

Disturbance from a variety of human activities in the Arctic, such as shipping and oil and gas development, can also have negative impacts on walruses. Marine traffic and noise associated with seismic surveys could interfere with the walrus migration or cause changes in behavior in the foraging grounds.

Although hunting of walruses for subsistence use could be considered a threat to the walrus population, current harvest levels are thought to be sustainable. Alaska Native hunters have expressed concern that walruses are sometimes difficult to hunt due to the lack of sea ice habitat. In 2015, a reduced harvest of walrus by subsistence hunters because of sea ice and weather conditions led to a food security crisis in the Bering Strait region of Alaska.

Current Conservation Efforts

In 2008, FWS was petitioned to list the walrus as threatened or endangered under the Endangered Species Act (ESA) and to designate critical habitat for the species. After a review of the best available science in 2011, FWS found that listing the walrus as threatened or endangered was warranted. However, the walrus remained a candidate species as FWS first considered other higher-priority species for listing. FWS made a final decision on the listing of Pacific walrus in October 2017 with the determination that the species does not warrant listing as threatened or endangered under the ESA. The Center for Biological Diversity (CBD) subsequently sued FWS in 2018 for not listing the walrus under the ESA, which was then rejected by a federal judge. After an appeal from CBD, the appeals court ruled in June 2021 that FWS had not provided sufficient justification for reversing its 2011 listing decision and must still do so. Walruses currently are afforded protection in the United States (with the exception of subsistence harvest by Alaska Natives) under the MMPA and they are listed in Appendix III of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

In 2020, the U.S. Coast Guard requested input on routing measures to minimize the impact of increased shipping on marine mammals, Alaska Native communities, and the marine ecosystem. The Commission analyzed the distribution and seasonal movements of numerous marine mammal species, including Pacific walrus, and submitted a letter to the U.S. Coast Guard recommending preferred and alternative shipping routes to protect marine mammals. Recommended areas to be avoided to minimize disturbance to walruses included areas where they aggregate in large groups to feed and rest, such as Hanna Shoal and Point Lay. The public comment period for this Port Access Route Study closed in September 2021.

Additional Resources

U.S. Fish and Wildlife Service – Marine Mammal Management – Alaska Region – Walrus

U.S. Fish and Wildlife Service – 2017 Final ESA Listing Decision for Pacific Walrus

U.S. Fish and Wildlife Service – Revised 2023 Pacific Walrus Stock Assessment Report – Alaska Stock

Pacific Walrus Coastal Haulout Database 1852-2016

U.S. Geological Survey – Alaska Science Center – Walrus Research

Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) – Walrus

Eskimo Walrus Commission

Kawerak Inc. – Eskimo Walrus Commission

North Atlantic Right Whale

The North Atlantic right whale (Eubalaena glacialis) is one the world’s most endangered species of large whale. North Atlantic right whales were first hunted as early as the 9th century by Norse whalers. Later, commercial whaling brought them to the brink of extinction by the early 1900s. The population off Europe had been virtually extirpated while a small population of perhaps a hundred or fewer survived in the western North Atlantic off the United States and Canada. After 1935, when an international agreement went into effect banning the hunting of all right whales, their numbers began to increase slowly. In recent decades, this slow recovery has been impeded by mortality and serious injury from vessel strikes and entanglement in fishing gear. North Atlantic right whales now occur almost exclusively along the east coasts of the United States and Canada, where they rely on a calanoid copepod, Calanus finmarchicus, as their primary food source.

The North Atlantic right whale is one of three right whale species, along with the North Pacific right whale and the southern right whale. Today, there are likely fewer than 500 right whales in the entire North Pacific, and approximately 30 individuals in the eastern North Pacific stock inhabiting U.S. waters, while southern right whale populations have seen steady increases since the end of commercial whaling in the southern hemisphere.

Right whale off Florida coast

Right whales off Florida coast. (New England Aquarium)

Species Status

Abundance and Trends

During the 1990s, the North Atlantic right whale population fluctuated between periods of slow decline and periods of slow growth. In the first decade of the 2000s, it grew steadily but at a rate well below those of many other populations of large whales. In 2010, the population entered a period of decline that appears to be continuing due to high levels of human-caused mortality and declining calf production. Human-caused mortality and serious injury, particularly entanglements and vessel strikes, is the greatest threat to recovery of the species. Today, there are approximately 360 North Atlantic right whales in existence, with fewer than 70 reproductive-age females in the population. Female numbers are declining more rapidly than males, and the corresponding loss of reproductive potential leads to an alarming concern about an increasing risk of extinction.

On October 23, 2023, the North Atlantic Right Whale Consortium announced that the North Atlantic right whale population estimate for 2022 was 356 (95% credible interval ranging from 346 to 363) individuals. The 2021 estimate was recalculated as 364 (95% credible interval ranging from 360 to 369). While these recent annual population estimates suggest the population decline may be leveling off, the overall multi-year population trend shows this species continues to face significant ongoing threats with annual mortalities exceeding recovery thresholds. These updated population estimates are considered preliminary pending and will be provided to the Atlantic Scientific Review Group for consideration in the 2024 Stock Assessment Review process. Twelve mother/calf pairs were observed in 2023, and as of 30 January 2024, seventeen mother/calf pairs have been observed in the 2023/2024 calving season.


Although North Atlantic right whales now occur almost exclusively along the east coasts of the United States and Canada, a few individuals have been observed entering the Gulf of Mexico and venturing across the Atlantic to European waters. Their current range is closely linked to their life history, contingent upon nursery areas and feeding grounds with the necessary habitat characteristics. Many North Atlantic right whales travel from their feeding grounds off the coast of the northeastern United States and Canada down to coastal waters of South Carolina, Georgia, and Florida in winter, while a portion of the population remains in more northern waters in areas such as south of Nantucket and around Cape Cod. The warm, shallow waters off the southeast U.S. coast serve as winter nursery grounds for the whales. The North Atlantic right whales then migrate north again along the east coast to their feeding areas, many arriving in Cape Cod Bay in early spring and then moving into productive waters of the Gulf of Maine and in more recent years, the Gulf of St. Lawrence. In recent years, the waters around Nantucket Shoals have been an important area with whales present nearly year-round. The North Atlantic right whale distribution seems to be shifting, yet questions remain about the permanency of the shift and the location of significant portions of the population at any given time.

Unusual Mortality Event: 2017 to Present

A bar chart showing the cause of death of North Atlantic right whales added to the Unusual Mortality Event (2017-2024)

Annual North Atlantic Right Whale Mortalities by Cause of Death, 2017-2024 (NOAA)

Elevated mortality and serious injury levels since June 2017 led NMFS to declare an Unusual Mortality Event (UME) for North Atlantic right whales, which remains an open investigation. A total of 122 cases of mortality (n=37), serious injury (n=34), and morbidity (n=51) are included under this UME as of February 2nd 2024, which represents more than 20 percent of the population.  Vessel strikes and entanglements in rope were the predominant cause of death for those that could be examined, however some of the whales that died could not be examined or were too decomposed to determine the cause of death. Most serious injuries (a designation indicating the injury is severe enough that the whale is likely to die from those injuries) and morbidity (sublethal injury or illness) cases involved entanglements, but include vessel strikes, as well as injuries or poor body condition of unknown cause.

While North Atlantic right whale deaths have been detected historically in U.S. waters, reflective of their distribution along the Atlantic coast of the U.S., the majority of the carcasses reported in 2017  and 2019  were concentrated in Canadian waters. The increasing presence of North Atlantic right whales in the Gulf of St. Lawrence in Canada is believed to reflect a northward shift in their prey, hypothesized to result from particularly strong climate-driven conditions, including ocean warming, in the waters of the northwestern Atlantic Ocean. This change in North Atlantic right whale distribution has led to an increase management and implementation of protective measures to reduce vessel strikes and entanglement in fishing gear in the Gulf of St. Lawrence.

Right Whale Mortality Since 1970

Right whale mortalities from collisions with ships, entanglement in fishing gear, perinatal (new born calf) deaths, and unknown causes (NMFS). Note that individual whales that were seriously injured (by vessel strike or entangled in gear) and not resighted are included.

What the Commission Is Doing

Presentation at Consortium Meeting

The Commission presented general updates to the North Atlantic Right Whale Consortium Meeting in 2021.

Stakeholder Engagement and Managing Impacts of Fishing

To reduce threats due to fishery interactions to the North Atlantic right whale population and other large whales in the Atlantic, in 1996 we recommended that NMFS establish a take reduction team in 1996, which led to the establishment of the Atlantic Large Whale Take Reduction Team (ALWTRT) and the developed of a Take Reduction Plan (TRP) in 1997. A representative of the Commission has been a member of the team since its inception. More recently, the Commission expressed concern to NMFS regarding the 2017-19 spike in human-caused serious injuries and deaths of North Atlantic right whales, the population’s low birthing rate and declining population size, and the need for immediate, strong measures to mitigate human-based threats to the species. In March of 2021, the Commission submitted a letter to NMFS on the intent to prepare a draft environmental impact statement and to amend the current Atlantic Large Whale Take Reduction Plan iterating these concerns and offering specific recommendations for management actions.

In addition to engaging on the ALWTRT, the Commission has awarded research grants aimed at right whale conservation. For example, the Commission provided funding to evaluate the potential use of ropeless fishing systems in lobster pot fisheries back in 2016. A project focused on evaluating the efficacy of using broad-scale ship speed restrictions in the U.S. East Coast Exclusive Economic Zone for reducing large whale mortalities was funded in 2020. In 2021, the Commission awarded a grant that supports advancing whale conservation and outreach with sustainable infrastructure for WhaleMap, and a second award to design an international virtual fishing gear marking system to reduce whale entanglements.

At its Annual Meeting on 5-7 April 2017 in North Falmouth, MA, the Commission devoted a session to receiving and reviewing recent information on the status of North Atlantic right whales. Among other things, it was noted that annual calf production in recent years has fallen to its lowest rate in 38 years and that the frequency and severity of entanglement-related wounds has been increasing significantly. Based on the information presented and discussed at the meeting, the Commission concluded that entanglement in fishing gear was the single greatest human-caused threat to North Atlantic right whales, and that measures to reduce the lethal and sub-lethal effects of entanglement in both the United States and Canada were inadequate.

Efforts to Reduce Impacts of Ship Strikes

The Marine Mammal Commission is continuing to monitor right whale deaths and injuries caused by ship strikes in U.S. waters, and making efforts to minimize their occurrence. Aside from an assumed vessel strike in 2017, the vessel speed zones that were established in 2008 by the National Marine Fisheries Service (NMFS) to reduce collisions with right whales by large vessels have been largely effective. In March 2014, the Commission recommended denial of a petition by the American Pilots Association requesting that dredged channels be exempted from speed restrictions in management areas. In 2014, we met with NMFS staff to review the status of the petition and also reviewed its status at our Annual Meeting in May 2015. NMFS denied the petition in October of 2015.

In June 2020, NMFS released a report that reviewed and synthesized many aspects of the effectiveness of the 2008 rule, including the increasing use of speed limits to protect whales in other parts of the country and world, volume of traffic and regulated vessel compliance with speed regulations, volume of non-regulated small-vessel traffic, effectiveness of the rule in reducing the number of serious injuries and deaths, vessel sizes involved in strikes of right whales, navigational safety, economic impacts, enforcement, and outreach. The Commission submitted a letter to NMFS on the North Atlantic right whale vessel speed rule assessment.

The Commission hosted a webinar on April 12, 2022 focused on “Federal Agency Approaches to Reducing Vessel Strike of Cetaceans”.  The aim of this workshop was to review Federal vessel-routing and speed-reduction programs, their elements and effectiveness, identify locations where additional measures are or may be needed, and consider recommendations for next steps.  These discussions included evaluations of the effectiveness of the Right Whale Vessel Speed Rule, incentive programs for industry environmental compliance and participation, as well as tools, such as Whale Map and the Whale Alert app, for communicating whale presence in areas where vessels and whales co-occur.

Commission Reports and Publications

Laist, David W., Knowlton, Amy R., and Pendleton, Daniel. 2014. Effectiveness of mandatory vessel speed limits for protecting North Atlantic right whales.

Laist, David W., Knowlton, Amy R., Mead, James G., Collet, Anne S., and Podesta, Michela. 2001. Collisions Between Ships and Whales.

Reports prepared for the Marine Mammal Commission:

Lowry, Lloyd, Laist, David W., and Taylor, Elizabeth. 2007. Collisions Between Ships and Whales.

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

Reeves, Randall R., Read, Andrew J., Lowry, Lloyd, Katona, Steven K., and Boness, Daryl J. 2007. Report of the North Atlantic Right Whale Program Review.

Commission Letters

Letter Date Letter Description
October 31, 2022

Letter to NMFS on detailed comments and recommendations on proposed amendments to the North Atlantic right whale (NARW) vessel speed strike reduction rule.

October 18, 2022

Letter to NMFS on the notice of Intent to prepare an Environmental Impact Statement assessing amendments to the Atlantic Large Whale Take Reduction Plan.

September 2, 2022

Letter to NMFS on proposed amendments to the North Atlantic right whale (NARW) vessel strike reduction rule.

August 29, 2022

Letter to US Coast Guard regarding its request for information regarding the Approaches to Maine, New Hampshire, and Massachusetts Port Access Route Study.

March 26, 2021

Letter to NMFS on the North Atlantic right whale vessel speed rule assessment.

March 1, 2021

Letter to NMFS on the proposed amendment to the Atlantic Large Whale Take Reduction Plan and draft Environmental Impact Assessment. 

February 19, 2021

Letter to NMFS on the Draft Biological Opinion regarding the impact of the American lobster and Jonah crab federal fisheries on the North Atlantic right whale.

September 23, 2019

Letter to NMFS on the notice of intent to prepare a draft environmental impact statement and to amend the Atlantic Large Whale Take Reduction Plan.

August 12, 2019

Letter to NMFS conveying Commission’s concerns regarding the 2017-19 spike in human-caused serious injuries and deaths of North Atlantic right whales, the population’s low birthing rate and declining population size, and the need for immediate, strong measures to mitigate human-based threats to the species

June 19, 2017

Letter to NMFS on the role of entanglement in reducing North Atlantic right whale abundance and management actions to monitor and reduce fishery-related interactions

April 19, 2017

Follow-up letter to NMFS from the Marine Mammal Commission’s 2017 Annual Meeting on North Atlantic right whales

April 13, 2016

Letter to U.S. Coast Guard on Atlantic Coast Port Access Route Study Final Report

April 21, 2015

Letter to NMFS on proposed modification of critical habitat for North Atlantic right whales

April 20, 2015

Letter to NMFS on proposed exemption of various state waters from the Atlantic Large Whale Take Reduction Plan and establishment of new gear marking requirements

November 21, 2014

Letter to NMFS on proposal to delay the start date for the Massachusetts Restricted Area under the Atlantic Large Whale Take Reduction Plan

March 4, 2014

Letter to NMFS on a petition to exempt dredged channels from vessel speed restrictions

September 13, 2013

Letter to NMFS on proposed rule to reduce right whale entanglement in commercial trap/pot and gillnet fishing gear

August 5, 2013

Letter to NMFS on proposed rule to delete the expiration date for regulations limiting vessel speeds

April 20, 2012

Letter to NMFS on report evaluating the effectiveness of the final rule to implement vessel speed restrictions to reduce the threat of vessel collisions

Learn More


The primary causes of mortality and injury to right whales are entanglement in fishing gear and strikes by vessels. Another potential threat include spills of hazardous substances from ships or other sources. Lastly, noise from ships and industrial activities within their range is a great concern for the whales, and the Commission provides comments on proposed activities and recommendations on how to avoid or mitigate such threats.

Current Conservation Efforts

recovery plan for the species was adopted in 1991 and updated in 2005. In 1994, three areas were designated as critical habitat. In January 2016 those areas were expanded and consolidated into two large areas, one covering waters off the northeastern United States in the Gulf of Maine from the U.S.-Canada border to eastern Massachusetts, and the other area along the southeast coast from southern North Carolina to central Florida (see NOAA National Marine Fisheries Service (NMFS) website for critical habitat maps). NOAA Fisheries appointed two recovery teams, the Northeast Implementation Team (NEIT) and the Southeast lamentation Team (SEIT), to assist with the development and implementation of the North Atlantic Right Whale recover plan.  The NEIT and SEIT assists NOAA Fisheries Greater Atlantic Regional Fisheries Office and the Southeast Regional Office, respectively, on implementation of the recovery plan and issues related to the status and conservation of North Atlantic right whales.

NMFS and the Coast Guard have taken both regulatory and non-regulatory steps to reduce the threat of ship strikes, including mandatory vessel speed restrictions in Seasonal Management Areas, modification of international shipping lanes, enforcement, and public outreach.

To address entanglement in fishing gear, NMFS established the Atlantic Large Whale Take Reduction Team. This team has been unable to agree on all measures needed to meet take reduction goals and the NMFS has therefore developed a plan it believes will be necessary to reduce the incidental serious injury and mortality of right whales, as well as other whales. NMFS is in the process of considering additional mitigation measures in response to the impact of Northeast fisheries on North Atlantic right whales.

On February 3, 2022, NMFS announced its intent to conduct a 5-year review of the North Atlantic right whale.  NMFS is required by the Endangered Species Act to conduct this 5-year status review to ensure listing classifications of the species is accurate based on the best scientific and commercial data available at the time of the review.

Additional Resources

NMFS Marine Mammal Stock Assessment Reports by Species/Stock – Right Whale, North Atlantic

NMFS 2005 Recovery Plan for the North Atlantic Right Whale

North Atlantic Right Whale Recovery Plan Northeast U.S. Implementation Team 

North Atlantic Right Whale Recovery Plan Southeast U.S. Implementation Team 

NOAA Interactive Map of North Atlantic Right Whale Sightings

Canada – WhaleMap: Latest Right Whale Observations

NMFS – Reducing Vessel Strikes to North Atlantic Right Whales

NMFS – North Atlantic Right Whale

North Atlantic Right Whale Consortium

North Atlantic Right Whales: Evaluating Common Misconceptions

North Atlantic Right Whale Tagging Workshop Report


The tiny vaquita porpoise is the world’s most endangered marine mammal. Its numbers are decreasing with approximately 10 remaining. Vaquitas die from entanglement in illegal gillnets. Gillnets are used in a lucrative illegal fishery for totoaba that serves an illegal trade of swim bladders to China as well as in shrimp and finfish fisheries. Although their use has been banned in all fisheries, and in the absence of government enforcement or support for the use of alternative gear, gillnets continue to be used in all of these fisheries, including in the Zero Tolerance Area designated for protection of the vaquita in their habitat.


Surfacing vaquitas. (Paula Olson)

Species Status

Abundance and Trends

The tiny vaquita porpoise is the world’s smallest and most endangered cetacean species. The vaquita remains on the brink of extinction with approximately 10 remaining in 2023. Analysis of acoustic data from 2011 to 2018 combined with visual observations in 2017 and 2018 showed an estimated average annual rate of decline of 33%, corresponding to a population decline of 98.6% over this period. Eleven dead vaquitas were found between March 2016 and March 2020 and the cause of death for eight of those animals was directly attributed to gillnets.


The vaquita split from its closest taxonomic relatives 4.8 million years ago and is now endemic to a small range (4,000 km2) in the turbid waters of the northern Gulf of California, Mexico.

A map of the vaquita's range in the Gulf of California. Included in the map is the biosphere reserve, the vaquita refuge, and the gillnet-exclusion zone, all of which are in the northern region of the gulf.

Vaquita range map and protection zones. Photo credit: Smithsonian Institution


Given the extreme concern over the safety of vaquitas in their natural habitat, the eighth meeting of theComité Internacional para la Recuperación de la Vaquita (CIRVA-8), held in November 2016, recommended that the Mexican Government institute a carefully planned, step-wise attempt to determine whether some vaquitas could be caught and held in a temporary sanctuary until they could be safely returned to a gillnet-free environment. CIRVA-9 concluded that given the recent deaths of at least six animals since CIRVA-8 and the high levels of illegal fishing activity in the Upper Gulf, the only hope for the survival of the species in the short term was to capture vaquitas and bring them into human care. Therefore, CIRVA strongly endorsed the Vaquita Conservation, Protection and Recovery (VaquitaCPR) plan and recommended that as many individuals as possible be captured in October and November 2017 and held until the Upper Gulf is safe for their return. There was grave concern that the vaquita will follow the Yangtze River dolphin (baiji) and become the second cetacean species brought to extinction in the 21st century if further action is not taken to save the species.

VaquitaCPR undertook an ambitious field season, based out of San Felipe, Mexico from 10 October to 10 November 2017. A team of 65 scientists from nine countries was on the water for five full days and eight partial days during the operational time frame as dictated by weather. Vaquitas, in groups of one to three, were seen on eight of these days. Catch nets were set on three days and two vaquitas were captured during field operations. As noted on the VaquitaCPR website, “The first animal, an immature female, was released after veterinarians determined she was not adapting to human care. The second animal, a mature female, that wasn’t pregnant or lactating, was released after not being able to adapt to human care at “El Nido.” During the second release emergency medical care was required. Despite heroic efforts by the veterinary team to save the animal’s life, she did not survive.”

Following the field season, the Mexican government, VaquitaCPR, and CIRVA evaluated next steps. In early December 2017, CIRVA conducted its 10th meeting at the Southwest Fisheries Science Center in La Jolla, California and released the CIRVA-10 report. Their main conclusion was that the status of the vaquita continues to worsen and that no more than 30 animals remained by mid-2017. Further, the committee accepted the conclusions of the VaquitaCPR team and an independent review panel that additional rescue efforts should be suspended. Moving forward, CIRVA recommended to the Government of Mexico that the first and immediate conservation priority must be to strengthen enforcement efforts and fishing regulations, including a complete ban on gillnet possession and use throughout the range of the vaquita. The CIRVA team also issued a specific recommendation to implement ‘enhanced’ enforcement during the December 2017 – May 2018 totoaba season in areas of vaquita and totoaba gillnet overlap.

One of the real advances of this effort was the use of underwater acoustic monitoring to detect vaquitas on a daily basis and provide information for the visual search team. This was built on the annual program of acoustic monitoring that has informed estimation of vaquita abundance over the last decade. Despite the extensive loss of equipment stolen by fishermen, real-time acoustic monitoring has been used to a limited extent to inform visual sighting efforts in 2020 and 2021.

What the Commission Is Doing

The Marine Mammal Commission supports U.S. government efforts with the Government of Mexico and the international community to address the threat to this critically endangered marine mammal – incidental mortality in illegal and legal fisheries bycatch – and it has a long history of providing funding and international scientific and technical expertise to aid those efforts. The Commission has supported the meetings of the international recovery team (CIRVA) and international efforts to assess vaquita abundance, trends, and the effectiveness of measures taken by Mexico to slow the species’ decline. The Commission has supported annual acoustic monitoring of this species since 2011 and it is committed to continuing to assist Mexico in its efforts to prevent the vaquita’s extinction. Members of Commission staff, Commissioners, and Scientific Advisors served as advisors to the VaquitaCPR program, were on the leadership team, and participated in all aspects of planning and fieldwork.

Over the past decades, the Commission has taken a leadership role, in collaboration with other U.S. government and Mexican agencies, to explore ways to provide communities in the northern Gulf of California with financially, socially, and ecologically viable alternatives to the gillnet fishing that is currently driving the vaquita toward extinction and to build markets for seafood caught without harming vaquitas. The Commission has provided financial support to develop, test, and introduce vaquita-safe fishing gear and methods, increase the effectiveness of protected areas, strengthen fisheries enforcement and trade controls, and develop market incentives to sell products caught with vaquita-safe gear. The Commission will continue to press for enforcement of the permanent ban on gillnets whether used by fishermen in the cartel-driven totoaba fishery or the fishery for shrimp and finfish.

Commission Reports and Publications

Related reports:

June 2023: Survey report for vaquita research 2023

December 2021: Survey report for Vaquita research 2021 final.docx (

April 2021: Report on using expert elicitation FINAL.docx (

February 2019: Report on the Eleventh Meeting of the International Recovery Team for Vaquita(Comité Internacional para la Recuperación de la Vaquita (CIRVA-11))

December 2017: Report of the Tenth Meeting of the International Recovery Team for Vaquita (Comité Internacional para la Recuperación de la Vaquita (CIRVA-10))

April 2017: Report of the Ninth Meeting of the International Recovery Team for Vaquita (Comité International para la Recuperación de la Vaquita (CIRVA-9))

November 2016: Report of the Eighth Meeting of the International Recovery Team for Vaquita (Comité International para la Recuperación de la Vaquita (CIRVA-8))

May 2016: Report of the Seventh Meeting of the International Recovery Team for Vaquita (Comité International para la Recuperación de la Vaquita (CIRVA-7))

July 2014: Report of the Fifth Meeting of the International Recovery Team for Vaquita (Comité International para la Recuperación de la Vaquita (CIRVA-5))

Commission Letters

Letter Date Letter Description
September 21, 2017

Letter to NMFS on petition to ban importation of commercial fish or products that have been caught with commercial fishing technology that results in incidental mortality or serious injury of vaquita

April 10, 2009

Letter to the U.S. Department of State urging commitment of funds to support efforts to conserve and recover the vaquita in the Gulf of California

Learn More


Vaquitas are threatened by entanglement in gillnets used to illegally catch the endangered totoaba (Totoaba macdonaldi), a large and endangered fish species also endemic to the upper Gulf of California. This fishery, which first re-emerged in the early 2010’s and involves large-mesh gillnets exceptionally lethal for vaquitas, is driven by the high price and demand for totoaba swim bladders in China. Use of gillnets for shrimp and finfish fisheries, which also entangle vaquitas, has been banned in the upper Gulf of California since 2015.

Both active and abandoned gillnets pose a threat. In May 2016, CIRVA-7 noted that many totoaba nets were being abandoned as poachers sought to avoid detection and enforcement, and the committee called for efforts to find and remove such gear in the range of the vaquita. In response Sea Shepherd Conservation Society initiated efforts to remove and destroy or recycle the illegal gillnetting gear. This program, which was joined by the Museo de la Ballena and the Government of Mexico, continued through 2020 as the illegal totoaba fishing continued unchecked, with 106 recently set nets removed by the end of February in the 2019-20 fishing season by Sea Shepherd vessels alone. The net removal program was halted in January 2021 following extensive civil unrest in late 2020.

In fall 2019, the Mexican government announced it would no longer provide compensation to the fishermen whose livelihoods were threatened by the prohibition of gillnet fishing for shrimp and finfish within the upper Gulf. The government also refused to provide support for fishermen wishing to use alternative gear that would not entangle vaquitas. Facing economic hardship, many of the displaced fishermen returned to fishing for shrimp with gillnets without authorization.

The deployment, by the Mexican Navy, in August 2022, of 193 concrete blocks with 3m high metal hooks designed to entangle gillnets in the Zero Tolerance Area (ZTA) significantly reduced the fishing effort in the major portion of the current range of the vaquita.

Although the main threat to vaquitas is entanglement in gillnets, there is some concern that their small population size may also affect their persistence. The collaborators in the Vertebrate Genomes Project, including The Rockefeller University, Southwest Fisheries Science Center-NOAA, and the Mexican National Commission on Natural Protected Areas (CONANP) sequenced the vaquita genome from living tissue salvaged from animals caught in VaquitaCPR project. Analyses suggest that low genome-wide heterozygosity is due to long-term persistence as a small population rather than a recent loss of diversity, for example, from inbreeding, that might accelerate extinction. This suggests that vaquitas may be able to maintain diversity necessary for population health despite their small population size. These results support the findings of a 2022 study that suggest that vaquitas are not “doomed to extinction by inbreeding depression” and that they could recover if entanglements ceased.

Current Conservation Efforts

On 24 September 2020 the Government of Mexico announced an agreement between the Ministries of Agriculture and Rural Development, Environment and Natural Resources to promote the sustainable use of marine resources and the protection of the vaquita. The agreement established measures to regulate fisheries and landing sites in the northern Gulf of California and required the installation of vessel monitoring systems on all vessels with a permit or concession. The agreement also established a 225 square kilometer ZTA to serve as a year-round refuge area for protection of vaquita.

The 2022-2023 fishing season saw a 90% decrease in gillnetting in the ZTA. This is attributed to the deployment by the Mexican Navy, in August 2022, of 193 concrete blocks with 3m high metal hooks designed to entangle gillnets. The Navy and Sea Shepherd Conservation Society are monitoring the presence of fishing activity and taking action to relocate fishing vessels outside the ZTA and remove gillnets.

Despite these efforts, there is continued concern in the international scientific community that the Government of Mexico continues to question the incontrovertible evidence that gillnets are the primary source of vaquita mortality, and international environmental groups continue to call for further action to save the vaquita from extinction. 

On 26 July 2018, as rampant totoaba fishing continued, the U.S. Court of International Trade issued a preliminary injunction in a suit brought by conservation organizations “requiring defendants — several United States agencies and officials, and here collectively referred to as “the Government” — to ban the importation of fish or fish products from any Mexican commercial fishery that uses gillnets within the vaquita’s range.” On March 4, 2020, the National Marine Fisheries Service revoked the comparability finding under the MMPA for a number of fisheries operating in the habitat of the vaquita. The MMPA requires prohibition of the import of seafood caught with commercial fishing technology which results in the incidental kill or incidental serious injury of ocean mammals in excess of United States standards.

In June 2017, the Government of Mexico announced a permanent ban on the use of gillnets in the shrimp and finfish fisheries of the Upper Gulf of California to replace the two-year gillnet ban. An initiative between the “Museo de la Ballena” and local fishing cooperatives to develop alternative fishing gear for shrimp was launched in 2019. Three different types of “suripera” nets were designed by the local fishermen, who started testing them in late October 2019. The fishing gear appears to work effectively when shrimp are in shallow water, but is less effective in deeper water. Tests are continuing with the goal of refining the designs for broader testing.

The VaquitaCPR program (see Species Status section) began in 2017. The program was a carefully planned, step-wise attempt to determine whether some vaquitas could be caught and held in a temporary sanctuary until they could be safely returned to a gillnet-free environment. Unfortunately, vaquitas did not adapt well to captivity and capture attempts were discontinued. Instead, the team launched Project Esperanza, which focuses on gillnet removal, acoustic monitoring, supporting local fishers and organizations, and raising global awareness of the plight of the vaquita.

On April 16, 2015, the President of Mexico announced new measures to protect vaquitas, which have been largely implemented by the Mexican Navy and other agencies in a strong show of commitment. These included expansion of the protected area for vaquitas to encompass their entire range, a two-year ban on gillnets within this area, concerted enforcement, support for alternative fishing methods, and compensation to the fishing communities affected by the ban.

Additional Resources

International Union for Conservation of Nature (IUCN) Cetacean Specialist Group vaquita page

IUCN Cetacean Specialist Group News

NOAA Fisheries – Vaquita

Sea Shepherd Conservation Society Operation Milagro

Cook Inlet Beluga Whale

Beluga whales are found in seasonally ice-covered waters throughout arctic and sub-arctic regions. Five stocks are recognized in U.S. waters off Alaska, including one that is found almost exclusively in Cook Inlet. The endangered Cook Inlet beluga whale population is currently estimated at 331 individuals. The population has been experiencing an ongoing decline for more than two decades, although the latest abundance estimates from 2022 may indicate a reversal of that trend. The National Marine Fisheries Service (NMFS) selected this population for its Species in the Spotlight initiative to bring attention and focus to selected domestic marine species at risk of extinction.

Beluga whales swimming underwater.

Belugas in the Arctic. (NOAA)

Species Status

The Cook Inlet beluga whale stock was estimated to number about 1,300 animals at the time the Marine Mammal Protection Act (MMPA) was enacted in 1972, but it declined sharply in the 1990s. Between 1994 and 1998, the stock declined by approximately 50 percent due largely to unsustainable subsistence harvesting. It was assumed that once hunting was controlled in 1999, the population would begin to recover.

NMFS listed the Cook Inlet beluga whale population as endangered under the Endangered Species Act (ESA) in 2008. Because the population, on average, has remained below 350 whales since then, no subsistence harvesting has been allowed under the applicable regulations.

The most recent abundance estimate for the Cook Inlet population is 331 individuals, based on aerial surveys conducted in June 2022. Although the 2022 abundance estimate is higher than the 2018 estimate of 279 individuals, and may indicate that the population is increasing, the low growth rate of this population, coupled with increasing human activities in beluga whale habitat in Cook Inlet, raise significant concerns about whether this population will be able to recover.

Critical Habitat

Two areas within Cook Inlet have been designated as critical habitat. These areas include all waters in the upper inlet except for a small exclusion area at the mouth of Knik Arm, nearshore areas in the southwestern part of the inlet, and Kachemak Bay on the eastern side of the inlet.

Map of Cook Inlet beluga whale critical habitat.

Map of Cook Inlet beluga whale critical habitat. (NOAA)

Status Review

In 2017, NMFS issued its first five-year status review for the Cook Inlet distinct population segment of beluga whales. The Endangered Species Act requires status reviews to be conducted every five years for listed species. The review determined that although the population is not increasing as expected, it is not declining precipitously, and, therefore, the probability of extinction is lower than in previous analyses. The review also stated that the population appears to now be consolidated into the upper part of Cook Inlet for much longer periods of time each year. The upper part of Cook Inlet is beluga whale habitat that is most prone to the effects of human development. NMFS announced its intent to conduct a subsequent five-year status review in February 2021, requesting new information on the status, threats, and recovery of Cook Inlet beluga whales that may have become available since the previous status review in 2017. NMFS completed its second five-year status review in September 2022, concluding that the Cook Inlet beluga whale population should retain its status as endangered.

Recovery Plan

A recovery team for the stock was established in 2010 and submitted a first draft of a recovery plan to NMFS in 2013 before being disbanded. Working from that draft, NMFS published a draft plan for public review and comment on May 15, 2015, on which the the Commission submitted comments.

NMFS finalized the Cook Inlet Beluga Whale Recovery Plan in December 2016. The recovery plan includes: 1) a description of site-specific management actions that are necessary to achieve the plan’s goal for the conservation and survival of the Cook Inlet belugas, 2) objective, measurable criteria which, when met, would result in a determination that the Cook Inlet belugas may be removed from the ESA, and 3) estimates of the time required and the cost to carry out those measures needed to achieve the plan’s goal and to achieve intermediate steps toward that goal.

The recovery plan identified ten potential threats and ranked them in order of their overall relative concern to the Cook Inlet beluga population, as follows:

Threats of High Relative Concern

  • Catastrophic events (e.g., natural disasters; spills; mass strandings);
  • Cumulative effects of multiple stressors; and
  • Noise.

Threats of Medium Relative Concern

  • Disease agents (e.g., pathogens, parasites, and harmful algal blooms);
  • Habitat loss or degradation;
  • Reduction in prey; and
  • Unauthorized take.

Threats of Low Relative Concern

  • Pollution;
  • Predation; and
  • Subsistence hunting.

Priority recovery actions include continuing to conduct aerial and photo-identification surveys to estimate abundance, and analyzing population trends, calving rates, and distribution. NMFS estimates that recovery of Cook Inlet beluga whales may take at least two generations (50 years).

NMFS has established a Cook Inlet Beluga Whale Recovery Implementation Task Force, which is overseen jointly by NMFS and the Alaska Department of Fish & Game (ADF&G). The purpose of the Task Force is to advise NMFS and ADF&G on issues related to the recovery of beluga whales in Cook Inlet, including practicable and effective ways to implement the recovery plan. The Task Force is also a forum to increase communication and coordination between agencies and stakeholders working to recover Cook Inlet beluga whales. The Task Force has an Executive Leadership Panel, Recovery Coordinators, and three Committees focused on Research, Habitat and Threats, and Outreach.

The Commission participates on the Task Force’s Habitat and Threats Committee. The Habitat and Threats Committee is focused on 1) improving the understanding of the existing habitat and threats, 2) identifying and assessing other potential threats to Cook Inlet beluga whales, 3) assessing the degree to which known and other potential threats are impeding recovery, and 4) identifying ways to improve mitigation or abatement of threats.

What the Commission Is Doing

The Marine Mammal Commission has focused on efforts to conserve the Cook Inlet beluga whale since the mid-1990s. We advocated for the species listing under the ESA. We also participated as a party to the formal rulemaking that established limits on the allowable taking of Cook Inlet beluga whales by Alaska Natives for subsistence. In addition, we have recommended that NMFS (1) give high priority to research directed at understanding the causes of the observed population trends, (2) support continuation of ongoing photo-identification work, (3) proceed cautiously in pursuing a large-scale biopsy research program for the population, (4) develop a robust plan for responding to stranding events, (5) fund annual abundance surveys, and (6) develop mechanisms for assessing cumulative impacts from multiple stressors on the population. The Commission continues to recommend in its letters regarding incidental take applications that NMFS and other agencies refrain from issuing authorizations for additional human activities in Cook Inlet that could affect beluga whales until they have a better basis for concluding that those activities will not exacerbate an already significant risk of extinction.

Commission staff helped to plan and participated in the November 2014 workshop in Anchorage, Alaska on Conservation and Recovery of Cook Inlet Beluga Whales in the Context of Continued Development. Commission staff also participate on the Cook Inlet Beluga Whale Recovery Implementation Task Force as a member of the Habitat and Threats Committee.

Commission Reports and Publications

For more information on the Cook Inlet beluga whale, see the Commission’s 2012 annual report (pages 59 – 63).

Commission Letters

Letter Date Letter Description
December 13, 2021

Letter to BOEM on its draft environmental impact statement for Cook Inlet Lease Sale 258.

September 16, 2019

Letter on the modification of letter of authorization for Hilcorp Alaska LLC to take marine mammals incidental to oil and gas activities in Cook Inlet, Alaska. 

August 5, 2019

Application from Alaska Gasline Development Corporation to take marine mammals incidental to construction of the Alaska Liquefied Natural Gas Project in Cook Inlet, Alaska. 

May 1, 2019

Letter to NMFS regarding an application from Hilcorp Alaska and Harvest Alaska to take marine mammals incidental to conducting various oil and gas-related activities in Cook Inlet, Alaska.

March 29, 2018

Letter to NMFS regarding an application from Harvest Alaska LLC to take marine mammals incidental to the installation of pipelines in Cook Inlet, Alaska

October 5, 2017

Letter to NMFS regarding the notice of intent to prepare an Environmental Assessment for activities requiring incidental take authorizations for 2018 in Cook Inlet, Alaska

September 6, 2016

Letter to BOEM regarding an environmental impact statement for Lease Sale 244 within the Cook Inlet, Alaska, Outer Continental Shelf planning area

July 13, 2016

Letter to NMFS regarding an application from BlueCrest Alaska Operating, LLC to take marine mammals incidental to conducting oil and gas exploration activities in Cook Inlet, Alaska

March 28, 2016

Letter to NMFS regarding a draft environmental assessment for the issuance of annual incidental take authorizations for oil and gas activities in 2016 in Cook Inlet, Alaska

March 7, 2016

Letter to NMFS regarding  an application from ExxonMobil Alaska LNG LLC to take marine mammals incidental to geophysical and geotechnical survey in Cook Inlet, Alaska

September 11, 2015

Letter to NMFS regarding a notice of intent to prepare a programmatic environmental assessment regarding the issuance of incidental take authorizations in Cook Inlet, Alaska

July 24, 2015

Letter to NMFS regarding an incidental take application from ExxonMobil Alaska LNG for a geophysical and geotechnical survey in Cook Inlet, Alaska

July 14, 2015

Letter to NMFS regarding comments regarding the draft Cook Inlet beluga whale recovery plan

April 20, 2015

Letter to NMFS regarding an incidental take application from SAExploration for a seismic survey in Cook Inlet, Alaska

April 13, 2015

Letter to NMFS regarding an incidental take application from Apache Alaska Corporation for seismic surveys in Cook Inlet, Alaska

December 29, 2014

Letter to NMFS regarding a notice of intent to prepare a programmatic environmental impact statement on the issuance of incidental take regulations for beluga whales and other marine mammals in Cook Inlet, Alaska

December 8, 2014

Letter to BOEM regarding a notice of intent to prepare an environmental impact statement for Lease Sale 244 within the Cook Inlet, Alaska planning area

October 14, 2014

Letter to NMFS regarding an incidental take application from BlueCrest for exploratory drilling activities in Cook Inlet, Alaska

September 4, 2014

Letter to NMFS regarding an incidental take application from Apache Alaska Corporation for a seismic survey in Cook Inlet, Alaska

January 9, 2013

Letter to NMFS regarding an incidental take application from Apache Alaska Corporation for a 3D seismic survey in Cook Inlet, Alaska

May 7, 2012

Letter to BOEM regarding the Proposed Cook Inlet Special Interest Lease Sale 244

October 21, 2011

Letter to NMFS regarding an incidental take application from Apache Alaska Corporation for a seismic survey in Cook Inlet, Alaska

October 3, 2011

Letter to NMFS regarding the 2011 Marine Mammal Commission annual meeting follow up on Cook Inlet beluga whale conservation

March 7, 2011

Letter to NMFS regarding concern over scientific independence of the Cook Inlet Beluga Whale Recovery Team

January 21, 2011

Letter to NMFS regarding scientific independence of members of the Cook Inlet Whale Recovery Team

June 28, 2010

Letter to NMFS regarding efforts to recover the Cook Inlet beluga whale population

March 29, 2010

Letter to NMFS regarding the notice of intent to prepare a recovery plan for the Cook Inlet beluga whale

March 3, 2010

Letter to NMFS regarding a proposed designation of critical habitat for the endangered Cook Inlet, Alaska stock of beluga whales

Learn More


Based on a long time series of abundance estimates it is clear that some factor or combination of factors is impeding the recovery of the Cook Inlet beluga whale from a precipitous decline due to overharvest by subsistence hunters during the 1990s. The causes of the population decline since 1999 remain undetermined, but may include increasing disturbance from industrial activities such as oil and gas exploration and development, construction, shipping, strandings, prey reduction, disease, habitat loss and degradation, predation, pollution, unauthorized take, and cumulative effects from these and other possible factors. These and other threats are discussed in more detail in the Cook Inlet Beluga Whale Recovery Plan.

Current Conservation Efforts

The Commission continues to review and provide recommendations to NMFS and other federal agencies concerning activities with the potential to affect Cook Inlet beluga whales adversely. The Commission sees NMFS’s selection of Cook Inlet beluga whales under Species in the Spotlight initiative as an opportunity to focus research efforts on identifying the causes of the population’s decline and management actions that can be taken to reverse that trend.

The Future/Next Steps

The Commission is monitoring implementation of the recovery plan and associated research and management actions, as part of the Cook Inlet Beluga Whale Recovery Implementation Task Force.

The Commission has expressed repeated concern that NMFS continues to make negligible impact determinations and to issue incidental take authorizations for various activities in Cook Inlet despite the fact that existing conditions appear to be having non-negligible impacts on the population and the possibility that the types of disturbance being authorized might be contributing to the ongoing decline. We will continue to press the need to limit potentially harmful human activities in Cook Inlet, and to implement more effective mitigation measures for activities that are authorized, in an effort to alleviate additional threats to the population.

Additional Resources

NMFS Species Overview – Beluga Whales

NMFS Species in the Spotlight: Priority Actions 2021-2025 for Cook Inlet Beluga Whale

Cook Inlet Beluga Whale Photo-ID Project

NMFS 2020 Stock Assessment Report – Cook Inlet Beluga Whale

The Cook Inlet Beluga Whale: A Population in Decline (poster)

Help Belugas – How the Public Can Help Study and Conserve Cook Inlet Beluga Whales

International Union for Conservation of Nature (IUCN) Global Assessment of Beluga Whales

North Atlantic Marine Mammal Commission (NAMMCO) Global Review of Monodontids (2017)

Southern Sea Otter

Sea otters live in shallow coastal waters in the northern Pacific Ocean. Two sea otter subspecies occur in the United States, the southern sea otter (Enhydra lutris nereis) and the northern sea otter (E.l. kenyoni). Southern sea otters, also known as California sea otters, live in the waters along the central California coastline. Historically, sea otters numbered in the hundreds of thousands in the North Pacific Ocean, but due to the fur trade, their numbers plummeted in the early 1900s. The threat to the southern sea otter posed by oil spills prompted its listing as a threatened species in 1977.

Sea otter. (U.S. FWS)

Species Status

Abundance and Trends

Before commercial hunting began in the mid-1700s, an estimated 150,000 to 300,000 sea otters occurred in coastal waters throughout the North Pacific Ocean. In 1911, hunting was prohibited under the terms of an international treaty for the protection of North Pacific fur seals and sea otters signed by the United States, Japan, Great Britain (for Canada), and Russia. By then, only a few thousand otters remained, including a small colony of about 50 otters along the coast of central California. By the time the Marine Mammal Protection Act (MMPA) was enacted in 1972, the California population had grown from as few as 50 to more than 1,000 individuals (an average annual growth rate of about 5 percent).

The U.S. Fish and Wildlife Service (FWS) listed the southern sea otter population as threatened under the Endangered Species Act (ESA) in 1977 and adopted a recovery plan for the population in 1982, which was updated in 2003. The recovery plan specifies that the species should be considered for delisting when the average population level over a three-year period exceeds 3,090 animals.

The FWS estimated southern sea otter abundance in 2016 was 3,272 individuals, a record high since 1972. The 2017 count declined somewhat, to 3,186 otters, but still exceeded the potential delisting threshold for a second straight year. The population has continued to decline, with a most recent abundance estimate of 2,962 otters in 2019. Full surveys were not completed from 2020 through 2023; the U.S. Geological Survey (USGS) is developing a modified analysis based on the partial surveys that were conducted during those years and plans to release the results in 2024. According to the 2021 stock assessment report, the observed decline through 2019 reflects lower numbers of otters in the northern and southern portion of the mainland range, offset somewhat by continued growth of the central portion of the mainland range and the translocated population at San Nicolas Island. The declining mainland counts since 2017 could be due to increased mortality from shark bites and other causes such as harmful algal blooms and disease.

California Sea Otter (Enhydra lutris nereis) Census Results, Spring 2019. Trends in southern sea otter abundance based on 3-year running averages of raw survey counts. Solid lines represent all sea otters and dashed lines represent independents only (non-pups). (USGS)


Historically, sea otters occurred in coastal waters throughout the rim of the North Pacific Ocean from northern Japan to Baja California, Mexico, with southern sea otters ranging from Oregon to Baja California.  Following almost two centuries of commercial hunting, sea otter populations were severely reduced; surviving southern sea otters consisted of a small colony of otters along the remote Big Sur coast of central California. Between 1911, when hunting was prohibited, and 1972, when the MMPA was passed, these otters recolonized more than 200 miles (370 kilometers) of the California coast. Today, southern sea otters occupy approximately 13% of their historic range; their current distribution extends along the central California coast from Monterey Bay to Point Conception. Mortality from shark attacks has been more frequent at the northern and southern extremes of population’s range and may be a factor in preventing or slowing range expansion of the population into seemingly suitable habitats.

California Sea Otter (Enhydra lutris nereis) Census Results, Spring 2019. Southern sea otter population density along the California coast. San Nicolas Island is not shown because spatially explicit analyses were not conducted there. (USGS)

San Nicolas Island Translocation Attempt

One of the primary threats to the southern sea otter is the risk of an oil spill. To reduce the risk of a large oil spill contacting otters throughout all or much of the species’ range, the FWS, in the late 1980s, attempted to establish a separate population at San Nicolas Island through a translocation of otters from the mainland range. The population never grew as expected and in 2012, the FWS declared the translocation a failure. The FWS determined that moving the otters that remained on San Nicolas Island would likely result in several deaths to the animals and decided to allow the otters to remain at the island. Despite the translocation having been declared a failure, the population on San Nicolas Island continues to increase. The population has grown by about 10 percent per year over the past decade and contained about 146 otters in 2023. When the translocation program was established, it created a management zone from Point Conception to the Mexican border from which sea otters would be excluded. As a result of the failure finding, there no longer is a legal obligation to try to prevent expansion of the mainland population’s range south of Point Conception.

What the Commission Is Doing

The Commission continues to follow ongoing research into the status and trends of this population, both for the coastal “parent” population and the translocated population on San Nicolas Island. Although the FWS declared the translocation a failure, it is quite possible that otter numbers at San Nicolas will continue to grow.

The Commission also consults periodically with the FWS and marine mammal facilities to resolve questions about the placement of non-releasable otters from this population.

In 2017, the Commission commented on proposed revisions to the southern sea otter stock assessment report. The draft report identified the potential for sea otters to become trapped in gear used to catch crab, lobster, and finfish. The Commission identified a need to establish an observer program with sufficient coverage to obtain reliable information on the rate and circumstances surrounding the entrapment of sea otters in such gear. The Commission also recommended that, as a precautionary measure, gear modifications to reduce entrapment of sea otters be adopted for crab and lobster traps, similar to those that have been in place for finfish traps since 2002. In addition, the Commission noted the need to update the southern sea otter stock assessment report more frequently. The FWS published a notice of availability of the revised stock assessment report on 28 August 2017, in which it addressed the comments submitted by the Commission and others.

In 2020, the Commission commented on more proposed revisions to the stock assessment report. The Commission recommended ways to improve the potential biological removal estimate. Given that southern sea otters have failed to significantly expand their range over the past two decades and the recent decline in the population trajectory, the Commission also recommended that the FWS make its stock assessment reviews available annually. The revised stock assessment report was made available on 24 June 2021.

Commission Reports and Publications

For more information on southern sea otters, see the Commission’s 2012 annual report.

Commission Letters

Letter Date Letter Description
April 27, 2020

Letter to FWS regarding the draft revised stock assessment report for the southern sea otter

March 13, 2017

Letter to FWS with comments on the 2016 draft stock assessment report for the southern sea otter

January 25, 2017

Letter to FWS regarding an Application from California Department of Fish and Wildlife-Central Region to take southern sea otters incidental to construction activities in association with a tidal marsh restoration project in Elkhorn Slough, California

August 3, 2012

Letter to FWS regarding revised stock assessment report for the Southern sea otter

Learn More


While sea otters are vulnerable to natural predators such as sharks, the population also faces risks from other factors such as disease, contaminants, harmful algal blooms, availability of prey, and entanglement in commercial fishing gear. In addition, the risk of oil spills remains an ongoing concern.

Current Conservation Efforts

Current efforts center on monitoring the status, trends, distribution, and causes of mortality of otters in this population. A key indicator of recovery of the population is its ability to expand its range along the California Coast. Currently, it appears that shark predation is an important factor limiting range expansion, particularly in the northern end of the range.

Future actions to promote the conservation and recovery of the southern sea otter will depend on the results of ongoing research, particularly if needed to respond to human-caused sources of mortality. FWS, U.S. Geological Survey, and their partners are expected to continue to conduct annual abundance surveys and respond to strandings, including conducting necropsies to identify the causes of death for retrieved carcasses.

Additional Resources

U.S. FWS Southern Sea Otter Species Page

U.S. FWS Stock Assessment Report

USGS California Sea Otter Surveys and Research page

International Union for Conservation of Nature (IUCN) Sea Otter page

Marine Mammal Commission Sea Otter Reintroduction Fact Sheet

Northern Sea Otter

Sea otters live in shallow coastal waters off the northern Pacific. In the U.S., there are two distinct sea otter subspecies, the Northern sea otter and the Southern (or California) sea otter. Northern sea otters live in the waters off south Alaska, British Columbia, and Washington State.

Sea otters

Sea otters. Photo taken under U.S. FWS permit #MA-043219. (Ryan Wolt)

Species Status

Abundance and Trends

Historically, an estimated 150,000 to 300,000 sea otters occurred in coastal waters of the North Pacific Ocean. These populations were decimated by almost two centuries of commercial hunting. Since the 1980s, most northern sea otter populations have continued to recover.

In Alaska there are three stocks of northern sea otters—the Southwest stock, the Southcentral stock, and the Southeast stock. The Southwest stock, which includes otters in the Aleutian Archipelago, the Alaska Peninsula, and Kodiak Island, is listed as threatened under the Endangered Species Act (ESA). The Southcentral and Southeast Alaska stocks continue to grow or have stabilized and are not listed under the ESA. All three stocks in Alaska are protected under the Marine Mammal Protection Act (MMPA).

The overall sea otter population size of the Southwest Alaska stock has declined by more than 50% since the mid-1980s. The U.S. Fish and Wildlife Service (FWS) listed the Southwest Alaska stock as threatened in 2005 and designated critical habitat for the population in 2009. That designation includes waters out to either 100 meters from shore or out to the 20 fathom isobaths in most areas within the population’s range. FWS finalized a recovery plan for the Southwest Alaska sea otter in 2013. The most recent population estimate for this stock is 51,935 otters and is reported in the 2023 stock assessment report. It is believed that the overall population trend has stabilized in recent years. The abundance of Southwest Alaska sea otters in the western and central Aleutian Islands, however, declined by nearly 90 percent between the early 1990s and 2005. A less precipitous decline occurred over that same period in the eastern Aleutian Islands. One theory for the observed population declines in these areas is an increase in predation by killer whales. Other theories suggest that the observed declines are attributable to oceanographic changes or fisheries effects. Currently, the population trend in the South Alaska Peninsula is still in decline, while the other populations in Southwest Alaska are stable or increasing.

In contrast to the Southwest Alaska stock, the numbers of otters in the Southcentral and Southeast Alaska stocks have increased or stabilized despite thousands of sea otters from the Southcentral Alaska stock having died in Prince William Sound as a result of the 1989 Exxon Valdez oil spill. Rebuilding the population took about 25 years. The U.S. Geological Survey (USGS) published a 2014 report concluding that the population had recovered to pre-spill levels. Population levels in the Southcentral stock have now stabilized and may be increasing; there are estimated to be around 21,600 animals.

The stock of sea otters in southeastern Alaska has grown exponentially since their reintroduction in the late 1960s and have nearly doubled since the early 2000s. This growth, coupled with concern that sea otters are competing with commercial fisheries for sea urchins, sea cucumbers, crabs, and clams has led to calls from Alaska State officials and some fisheries groups for a cull of the population. Although there are now more than 22,000 sea otters in southeast Alaska and the population continues to increase, the population likely remains below its optimum sustainable population level, something that the USGS and FWS are currently assessing.

In Washington, sea otters were extirpated by the early 1900s. Around 1970, 59 otters were captured from Amchitka Island in Alaska and released along the outer coast of the Olympic Peninsula. Many of these translocated otters did not survive, but eventually, the population began increasing. The otter population north of La Push appears to be reaching equilibrium density, however the portion of the stock south of La Push has been increasing at approximately 22% per year since 1989. Survey counts in 2016 reported 1,380 otters south of La Push and 426 otters to the north.

Figure Credit: USFWS, “Sea Otter (Enhydra lutris kenyoni): Washington Stock” Stock Assessment Report, 2018 / Jeffries et al. 2016. Washington sea otter growth patterns from 1989 to 2016.


Before commercial hunting began in the mid-1700s, an estimated 150,000 to 300,000 sea otters occurred in coastal waters throughout the rim of the North Pacific Ocean from northern Japan to Baja California, Mexico. In 1911, hunting was prohibited under the terms of an international treaty for the protection of North Pacific fur seals and sea otters signed by the United States, Japan, Great Britain (for Canada), and Russia. By then, only a few thousand otters remained. The survivors were scattered among small colonies in remote areas of Russia, Alaska, British Columbia, and central California.

Since the prohibition on commercial hunting in 1911, northern sea otters have recolonized or have been reintroduced into much of their historic range. By the time the MMPA was enacted in 1972, remnant groups in Alaska had grown considerably and, in the late 1960s and early 1970s, several hundred otters were moved from Amchitka Island and Prince William Sound to try to reestablish populations in southeast Alaska and the outer coasts of Washington and Oregon. Historically, the Washington sea otter stock ranged along the Olympic Peninsula coast south to the Columbia River. Currently, these otters are found along the Olympic Peninsula from Pillar Point in the Strait of Juan de Fuca south to Point Grenville on the outer coast.

Oil Spill Impacts

Based on the limited range of the southern sea otter, the threat posed by oil spill prompted this stock to be listed as a threatened species under the Endangered Species Act in 1977. While northern sea otters did not receive a similar listing, oil spills are also a significant threat to these animals; the Exxon Valdez oil spill in 1989 demonstrated the severe and long-lasting impacts of oil spills on this species. Southcentral Alaskan sea otters near Prince William Sound were severely impacted by the Exxon Valdez oil spill. It was estimated that 1,000 to 5,500 sea otters died in the first few months after the spill. In some of the most heavily impacted areas, sea otter mortality approached 90%. While sea otters in this area have rebounded since the spill, long-term spill effects were observed for decades. Based on sea otter diving behavior, a study by the USGS suggested that sea otters in the most heavily impacted areas were still being exposed to oil on a regular basis, resulting in delayed recovery and continued early mortality through 2009. This population of otters was finally determined to be recovered to pre-spill abundance in 2013 (24 years post-spill) and it was concluded that any continued exposure to lingering oil was no longer of biological significance.

What the Commission Is Doing

The Commission is closely following work being done by the FWS, USGS, and others to monitor the status of the Alaska population stocks. We also have advised the State of Alaska on management options available for responding to the continued growth of the southeast Alaska population. The Commission reviewed updated draft stock assessment reports for the three Alaskan northern sea otter stocks in 2023.

Commission Reports and Publications

For more information on Southern sea otters, see the Commission’s 2012 annual report.

Commission Letters

Letter Date Letter Description
May 8, 2023

Letter to FWS regarding draft stock assessment reports for three stocks of northern sea otters in Alaska

July 24, 2019

Letter to FWS regarding an incidental take authorization for construction projects in Sitka and Hoonah, Alaska

April 18, 2019

Letter to FWS regarding an incidental take authorization for oil and gas activities in Cook Inlet

April 17, 2018

Letter to FWS on the draft revised stock assessment report for the northern sea otter stock in Washington State

June 13, 2016

Letter to FWS regarding an incidental take authorization for oil and gas activities in Cook Inlet

September 29, 2014

Letter to FWS regarding an incidental take authorization for oil and gas activities in Cook Inlet

July 17, 2013

Letter to FWS regarding a draft stock assessment report for three stocks of Northern sea otters in Alaska

May 17, 2013

Letter to FWS regarding request for comments on the interpretation of specific terms as they pertain to Alaska natives’ taking of sea otters

Learn More


Northern sea otters face a variety of threats throughout their range. In the western Aleutian Islands, killer whale predation, restricted habitat use, and possibly a decline in the number of otters this habitat can support due to ecosystem-level changes are primary concerns. Elsewhere in Alaska, competition with commercial shellfish fisheries, entanglement in commercial fishing gear, oil spills, disease outbreaks, contaminants, and subsistence harvests are the primary threats.

Current Conservation Efforts

Ongoing conservation efforts are directed at monitoring changes in abundance and distribution of northern sea otters and trying to ascertain the causes of declines in southwestern Alaska. Future actions to conserve the threatened southwest Alaska sea otter population will depend on the results of planned abundance surveys and additional research into the cause or causes of observed declines.

Researchers completed an analysis of carrying capacity for the growing Southeast Alaska stock in 2019 and estimated the carrying capacity for the entire southeast Alaska region to be 74,650 sea otters. The results of this study are expected to inform a determination of the stock’s status relative to its optimum sustainable population level, which in turn will dictate what management options might be available under the MMPA.

FWS is planning to conduct a ship-based sea otter survey and benthic sampling in the western Aleutian’s to assess the extinction risk of sea otters in this area. FWS is also planning to conduct a range-wide population survey of the Southeast stock to assess changes in distribution and abundance since 2011.

In addition, during fiscal year 2021, Congress directed FWS to study the feasibility and cost of re-establishing sea otters where they were once hunted to near-extinction along the Pacific coast in Oregon and Washington. The report is available on the FWS website. FWS determined that reintroduction is feasible, but additional information and stakeholder input are necessary. The Elakha Alliance, a nonprofit group with a mission to restore a healthy population of sea otters to the Oregon coast, is looking to the Congressional request to aid their efforts. The Elakha Alliance believes that the re-introduction of sea otters would make Oregon’s marine and coastal ecosystem more robust and resilient; sea otters’ well-known role in promoting the growth of kelp forests also contributes to carbon sequestration, or the removal of CO2 from the atmosphere, which could play a role in reducing global climate change.

Additional Resources

U.S. FWS Northern Sea Otter species page

U.S. FWS Stock Assessment Reports – Sea Otters

U.S. FWS Sea Otter management

USGS Nearshore Marine Ecosystem Research Program

Alaska Department of Fish and Game Northern Sea Otter species page

International Union for Conservation of Nature (IUCN) Sea Otter page

Marine Mammal Commission Sea Otter Reintroduction Fact Sheet

Mediterranean Monk Seal

The Mediterranean monk seal (Monachus monachus), the sole member of the genus Monachus, is one of two surviving species of monk seals. Like the Hawaiian monk seal, the Mediterranean species is endangered, numbering no more than 700 animals. A third species, the Caribbean monk seal, was driven to extinction in the 20th century. The Mediterranean monk seal has suffered millennia of exploitation, persecution, and harassment, and today all that remain are a few widely separated, fragmented populations that occupy, collectively, only a small portion of the species’ original range.

Mediterranean monk seal, Monachus monachus, in Gokova Bay, Turkey. (Shutterstock)

Species Status

Mediterranean monk seals are in danger of extinction, but there are some encouraging signs: conservation efforts and coordination among countries are improving, some populations are increasing in size, previously undocumented breeding areas have been discovered, and monk seals are beginning to appear in habitats and places where they had not been seen for decades. In the last several years, small numbers monk seals have been seen in Egypt, Lebanon, Israel, Cyprus, Albania, Montenegro, Croatia, Italy, Sardinia, Syria, Spain, and Libya, and breeding has been documented in some of these countries. In light of these positive signs, in November 2015 the IUCN reclassified the Mediterranean monk seal from ‘Critically Endangered’ to ‘Endangered.’

There is a long history of human exploitation and persecution of Mediterranean monk seals, stretching back from modern times to the Middle Ages, the Roman era and even to prehistoric times. Like other monk seals, Mediterranean monk seals likely rested and pupped on sandy beaches in many areas, but over centuries of exploitation and harassment, they now almost always rest and pup in inaccessible caves that contain sandy beaches. The low pup survival rate that occurs in Mauritania is thought to result from the use of caves where pups are at risk of being swept away during storms.

Mediterranean monk seals were found regularly throughout the Mediterranean, Marmara and Black Seas, along the West African coast to as far south as Cap Blanc, and in the Canary, Madeira and Azores Islands. In the 20th century, the species was eliminated, primarily by fishers, over most of that range, disappearing from Egypt, Israel, Cyprus, Lebanon, Montenegro, the Black Sea, Italy, Sicily, Sardinia, Corsica, France, the Balearic Islands, Spain, Tunisia, and Morocco.

They are now three isolated reproductive populations.

  1. Eastern Mediterranean: primarily in the islands of the Ionian Sea off western Greece, along the mainland coast of Greece, in the islands of the Aegean Sea between Greece and Turkey, along the Mediterranean coast of Turkey, and recently in northern Cyprus.
  2. Madeira Archipelago: west of Morocco and southwest of Portugal, in the Desertas Islands and on the island of Madeira.
  3. Mauritania: along a short stretch of the Cap Blanc Peninsula, on the west African coast south of the Madeira Archipelago.

The status of a very small population of monk seals in eastern Morocco and possibly Algeria, is unknown.

Given their reclusive habits, accurate and precise population estimates are not available, but monk seal researchers agree that there are no more than 700 seals in total. Researchers currently estimate that the eastern Mediterranean population is no larger than 450 adult animals, but this estimate is uncertain. The majority of these seals are found in Greece, with most of the remaining animals found in Turkey, although the latest research suggests the Turkey subpopulation may be declining. At one time, the largest population of nearly 320 animals had been on Cap Blanc Peninsula, but it was reduced to roughly 100 seals following a large die-off in 1997, possibly due to a toxic red-tide event. Since then, that population has rebounded and has been estimated recently to number approximately 360 seals. A small colony of approximately 20 seals exists in the Madeira Archipelago.

What the Commission Is Doing

In recent years, the Marine Mammal Commission’s Research Program has provided support to Greek scientists for work in four areas:

  1. Development of a genetic research protocol, and optimized sample collection and laboratory methods, to be used in a preliminary assessment of the genetic characteristics of monk seals in Greece. The results of this research, published in 2016, demonstrated that the species has extremely low levels of genetic diversity. Three genetically distinct populations were identified – Cap Blanc, Aegean Sea, and Ionian Sea.
  2. Monitoring monk seals recently discovered to be breeding at Evia Island, Greece, a 2013 research grant, which resulted in in two publications.
  3. Establishment of the “Hellenic Monk Seal Register” of genetic information on monk seals in Greece, also a 2013 research grant, which resulted in in one publication.
  4. The Commission is funding an effort in Albania to increase local awareness and stakeholder involvement in the region to encourage protection of Mediterranean monk seals.
  5. A 2018 grant funded research focused on the evaluation of marine protected areas at protecting juvenile Mediterranean monk seals.

In addition, the Commission has provided support for cooperative research efforts between scientists working on the conservation of Mediterranean and Hawaiian monk seals, and it participated in a scientific roundtable at the Greek Embassy to review and identify priorities for Mediterranean monk seal conservation. That meeting endorsed efforts to identify and protect core monk seal habitat and to develop community-based initiatives that enhance local involvement and seek support from people living near core seal habitat and from stakeholder groups, particularly those engaged in fisheries. Recently, the Commission has facilitated the formation of the Rare Pinniped Conservation Network, RAPCON, a network to foster organization and sustained collaboration among individuals working to conserve rare pinniped populations globally.

Commission Reports and Publications

To date, the Commission has not drafted any reports for the Mediterranean monk seal.

Commission Letters

Letter Date Letter Description
September 28, 2015

Letter to NMFS regarding an application from Lamont Doherty-Earth Observatory to take marine mammals incidental to a 2D and 3D geophysical survey in the eastern Mediterranean Sea

Learn More


Threats to Mediterranean monk seals include human encroachment and critical habitat destruction, alteration and fragmentation, deliberate harassment and killing by fishers who consider them competitors for fish and a source of damage to their fishing gear, and incidental drowning in gillnets. In a recent survey, fishers reported damage to their fishing gear by monk seals on 21 percent of their fishing trips. Deliberate killing has been the most frequently diagnosed cause of monk seal deaths in Greece, and is a serious problem in Turkey. One-third of monk seal deaths in Greece in the early 1990s were attributed to deliberate killing by fishers. In 2011 and 2012, nearly 20 percent of all well-documented monk seal deaths in Greece were attributed to deliberate human causes, such as gunshots likely inflicted by fishers. Disease outbreaks, toxic algal blooms, disturbance of pupping caves, rock-slides or cave collapses, shark predation, and abnormally low water temperatures are also threats to individual populations. In addition, recent research has found that the species has experienced a significant loss of genetic diversity and at least the eastern Mediterranean population, which likely contains genetically differentiated sub-populations, is experiencing significant levels of inbreeding.

Presumably as an accommodation to their harsh treatment by people, Mediterranean monk seals have retreated to what is likely marginal, suboptimal habitat. Along the Cap Blanc Peninsula, seals rest and pup in caves that are exposed to storms that can wash pups away. In Turkey, seals have been observed resting in the water in caves that do not have beaches or haul-out areas. It has been suggested that the species cannot recover unless it can reoccupy open beaches.

Although a small number of dedicated scientists and environmental groups have made significant advances toward Mediterranean monk seal recovery since the late 1970s, more efforts are needed. A major impediment has been the unwillingness or inability of national governments to carry out effective conservation programs or provide more than minimal levels of funding for monk seal research or conservation within their respective jurisdictions. As a result, most monk seal conservation work has depended on the efforts of (and funding from) non-governmental organizations such as MOm (The Hellenic Society for the Study and Protection of the Mediterranean Monk Seal) and CBD Habitat (Spain), and on government organizations such as the Madeiran Park Service (Serviço do Parque Natural da Madeira) (Portugal).

Current Conservation Efforts

Conservation efforts began in the 1970s, and today national and international laws and treaties provide protection throughout its range, including the establishment of protected areas, some of which prohibit or restrict fishing. In addition, non-governmental organizations contribute important conservation efforts, such as the rescue and rehabilitation of injured, sick and orphaned seals, public outreach and education, and research.

One of the first and most significant actions was in the northern Aegean Sea, where the National Marine Park of Alonissos was established by the government of Greece in 1992. Covering 2,200 km2 (850 mi2) of nearshore waters around the Northern Sporades Islands, the park was meant, in part, to protect one of the largest surviving colonies of monk seals, which numbered about 50 in 2000. Commercial fishing is restricted within a substantial portion of the park, and MOm has worked with local residents and park visitors to promote human attitudes and behavior that allows seals and people to coexist. Although enforcement of conservation measures in Greece has been weak, the government of Greece also established a national park on the northern coast of Karpathos and in 2019 created a marine protected area to protect one of the largest monk seal colonies in the Mediterranean.

Habitat protection is widely recognized as the greatest conservation priority. Monk seal researchers agree that a network of protected areas is necessary for the Mediterranean monk seal population to survive long term. In addition to the park in the Northern Sporades Islands, protected areas that restrict fishing have been established at locations on the Aegean and Mediterranean coasts of Turkey, in Cyprus, in the Desertas Islands in Madeira, and off the Cap Blanc Peninsula, Mauritania. At least some of the protected areas appear to have been effective in reducing entanglement rates and increasing the survival of pups. The fishing restrictions and pupping-cave protections provided on the Cap Blanc Peninsula have also contributed to that population’s recovery of the population from the die-off suffered by that population in 1997. Nonetheless, monk seal biologists and conservationists believe that much more habitat needs to be protected, and that monitoring and enforcement must be improved. The government of Turkey has enacted regulations that significantly increase limits on activities that can create disturbance in caves used by monk seals, and recently constructed an artificial ledge in a marine cave to increase the number of caves available for pupping.

Efforts to reduce deaths due to fisheries interactions are being made for all the populations. Those efforts include restricting fishing activities in protected areas, use of alternative fishing gear, and education of fishers.

In 2005, the Working Group of the Mediterranean Monk Seal in the Eastern Atlantic (part of the Bonn Convention) developed an Action Plan for the Recovery of the Mediterranean Monk Seal (Monachus monachus) in the Eastern Atlantic. The plan reflects a shared, international commitment by Mauritania, Morocco, Portugal and Spain to ensure the recovery and persistence of the monk seals in the region. The plan focuses on several objectives, including 1) coordinating and funding conservation actions, 2) monitoring and research, 3) reducing human sources of mortality, 4) protecting critical habitats, and 5) educating the public.

To provide a framework for monk seal conservation efforts in Greece, in 2009 MOm updated an earlier monk seal action plan by preparing a new five-year National Strategy Action Plan for the Conservation of the Mediterranean Monk Seal in Greece. This plan adjusted priorities to emphasize protection of seals in the wild, habitat protection at national and local levels, developing a national network of protected areas, and strengthening measures to protect seals moving outside of and between protected areas. The plan calls for national legislation to strengthen legal authority for seal protection and to establish a National Monk Seal Conservation Commission. Other elements include a vigorous public awareness program targeting commercial fishers and tourists, a national inventory of important habitat sites, stronger management ties between local communities and user groups in designated protected areas, legally enforceable conservation measures that are applicable throughout national waters, and expanded scientific research.

Additional Resources

General Information

International Union for the Conservation of Nature (IUCN): 2015 Mediterranean Monk Seal Assessment

NMFS: 2017 Mediterranean Monk Seal (Monachus monachus) 5-Year Review: Summary and Evaluation

National Resources on Monk Seals

Greece: MOm (The Hellenic Society for the Study and Protection of the Mediterranean Monk Seal)

Mauritania: CBD Monk Seal Conservation Program

Madeira: Life Madeira – Monk Seal

Turkey: SAD-AFAG (Underwater Research Society – Mediterranean Seal Research Group)

Selected Peer-Reviewed Publications

Mitogenomics of the endangered Mediterranean monk seal (Monachus monachus) reveals dramatic loss of diversity and supports historical gene-flow between Atlantic and eastern Mediterranean populations. Alba Rey-Iglesia et al. 2021. Zoological Journal of the Linnean Society.

Genetic and demographic history define a conservation strategy for earth’s most endangered pinniped, the Mediterranean monk seal Monachus monachus. Alexandros A. Karamanlidis et al. 2021. Scientific Reports.

An interview-based approach assessing interactions between seals and small-scale fisheries informs the conservation strategy of the endangered Mediterranean monk seal. Alexandros A. Karamanlidis et al. 2020. Aquatic Conservation – Marine and Freshwater Ecosystems

Prehistoric and historic distributions of the critically endangered Mediterranean monk seal (Monachus monachus) in the eastern Atlantic. Luis Mariano Gonzalez. 2015. Marine Mammal Science 31(3):1168–1192.

Shaping species conservation strategies using mtDNA analysis: The case of the elusive Mediterranean monk seal (Monachus monachus). Alexandros A. Karamanlidis. 2016. Biological Conservation 193:71-79.

The Mediterranean monk seal Monachus monachus: status, biology, threats, and conservation priorities. Alexandros A. Karamanlidis, et al. 2015. Mammal Review 46(2):92-105.

Freshwater Dolphins and Porpoises

Freshwater cetaceans include some of the world’s most highly adapted (= specialized) and threatened mammals. One species, the Yangtze River dolphin or baiji, became extinct early in this century. Five of the seven currently recognized cetacean species that are either obligate inhabitants of fresh water, or have freshwater geographical populations, occur in Asia. The other two species (with several subspecies) are found in the Amazon, Araguaia/Tocantins, and Orinoco River basins of South America. All of the freshwater species, subspecies, and populations that have been assessed for the International Union for Conservation of Nature (IUCN) Red List are considered endangered or critically endangered.

River dolphin swimming with head above water.

The South Asian river dolphin, Platanista gangetica, is found in India, Bangladesh, Nepal and Pakistan and includes two subspecies, the Ganges river dolphin and Indus river dolphin. (Zahangir Alom)

Species Status


Freshwater cetaceans (including six dolphin species and a porpoise) have declined dramatically in numbers and range, especially in Asia. The baiji (Lipotes vexillifer), a freshwater dolphin endemic to the Yangtze River in China, was declared extinct in 2006. The last verified sighting of this species occurred in 2002. Unsustainable bycatch in local fisheries likely drove this species to extinction.

Freshwater cetacean abundance is difficult to assess because populations are often broken up into different subpopulations, sometimes spanning multiple countries. Most populations, however, are thought to be declining and all are listed as endangered or critically endangered by the International Union for Conservation of Nature’s (IUCN’s) Red List of Threatened Species. For example, the boto (Inia geoffrensis), an endangered Amazon river dolphin, can be found in two river basins across six countries, from the river delta upstream to where the waters become impassible. There is no range-wide estimate for abundance or trend in abundance for this species, although they are generally thought to be declining. Monthly surveys have occurred in one section of the Brazilian Amazon since 1994 and have revealed a 6.7% annual decline in boto sightings from 2000 to 2017. In this same area, another Amazon river dolphin, the tucuxi (Sotalia fluviatilis), also appears to have declined by 7.4% annually from 1994 to 2017.


Freshwater cetaceans can be found in South America, in the Amazon and Orinoco river basins in Brazil, Bolivia, Colombia, Ecuador, Peru, and Venezuela, and in Asia, throughout several river systems in China, India, Bangladesh, Nepal, Pakistan, Indonesia, Cambodia, and Myanmar. Historically, many of these species ranged from tidal deltas into lakes and tributaries far upriver. Waterfalls, rapids, and shallow water, as well as man-made structures like dams, can act as barriers to dolphin distribution. This often results in completely or partially isolated subpopulations of cetaceans throughout the river basin. Many freshwater dolphins prefer shallow, murky water, and as a result have evolved to have poor eyesight, instead relying on echolocation to navigate and locate prey.

Mekong River Population of Irrawaddy Dolphins

A pair of Irrawaddy dolphins breaking the surface in the Mekong River (Photo courtesy of Jason Allen, of the Sarasota Dolphin Research Project).

A pair of Irrawaddy dolphins in the Mekong River (Photo courtesy of Jason Allen, of the Sarasota Dolphin Research Project).

In January 2023, the Commission supported the travel of an expert group to Cambodia to work with WWF-Cambodia and the Fisheries Administration on their research and conservation efforts on Mekong River Irrawaddy dolphins, continuing an international collaboration underway for over a decade. The most recent population estimate in 2020 was 89 and there is concern over the number of animals lost from the population over the last few years, as 26 have been found dead since then. Commission Chair Gulland conducted necropsy training for the WWF staff and the river guards, focusing on the diagnosis of bycatch and specimen archiving. She has been involved with the local team since 2009, evaluating causes of death in the population. Jason Allen, from the Sarasota Dolphin Research Project of the Chicago Zoological Society, participated in a photo-identification survey of the current dolphin habitat and worked with the team on photo-id methodology and analysis, continuing training started during a Commission sponsored capacity building trip of the Cambodian team to Sarasota in 2018. Dr. Brian Smith of the Wildlife Conservation Society focused on the river guard and law enforcement situation and Ph.D. student Sarah Tubbs from Newcastle University engaged with the team on survey methods, exploring the use of acoustic detections in the river. The trip came at a time of intense focus on the dolphins in Cambodia, as three dolphins were found dead in fishing gear in late December, spurring the Prime Minister of Cambodia to call for increased protection from this primary threat to the existence of this population. Led by Executive Director Thomas, the visiting expert team met with the Cambodian Director General of Fisheries, the U.S. Ambassador to Cambodia, and the USAID mission team to draw attention to the need to take further action to protect this small population.

The photo-ID survey team snaps a picture of a Irrawaddy dolphins in the Mekong River (Photo courtesy of Jason Allen, of the Sarasota Dolphin Research Project).

The photo-ID survey team for Irrawaddy dolphins in the Mekong River (Photo courtesy of Jason Allen, of the Sarasota Dolphin Research Project).

What the Commission Is Doing

The Marine Mammal Commission supports both targeted efforts to address the conservation of specific populations and regional efforts to strengthen freshwater cetacean conservation. Also, through its regular participation in the work of the International Whaling Commission Scientific Committee’s Sub-committee on Small Cetaceans, the Marine Mammal Commission seeks to make sure these “non-marine” marine mammals are given due consideration in accordance with their exceptional vulnerability.


In October 2009, the Commission co-sponsored a workshop in Samarinda, Indonesia, on Establishing Protected Areas for Asian Freshwater Cetaceans in Asia. Additionally, the Commission provided expertise to a meeting to draft an Indus River Dolphin (Platanista gangetica minor) Conservation Strategy and Action Plan, 2012 – 2022, held by WWF-Pakistan in Lahore, Pakistan, April 3-4, 2012. The Commission provided grant support to Gill Braulik for research on distribution, abundance, habitat use, and taxonomy crucial to understanding the conservation needs of the Indus River dolphin.

The Commission also participated in the Third Southeast Asian Marine Mammal Symposium (SEAMAM III) in Langkawi, Malaysia, from March 4-10, 2013. SEAMAM III considered issues related to the conservation and biology of coastal/inshore, estuarine and riverine marine mammals in Southeast Asia.

On December 9, 2014, an oil tanker collision spilled 350,000 liters of furnace oil into the waterways of the world’s largest mangrove forest in the Sundarbans, Bangladesh. This spill had the potential to impact the freshwater Ganges River dolphins (Platanista gangetica gangetica), as well Irrawaddy dolphins and finless porpoises (Neophocaena asiaeorientalis). In support of a joint United Nations/Government of Bangladesh Sundarbans oil spill response mission, the Commission funded Brian Smith and the Sundarbans biologists from the Wildlife Conservation Society to provide their expertise on the marine and freshwater cetacean species of the area and assist in the management of the spill and assessment of its impacts.

Mekong river guards burn confiscated gillnets removed from the core zone of Mekong river dolphin habitat. (Peter Thomas, Marine Mammal Commission)

The Irrawaddy dolphin (Orcaella brevirostris) population in the Mekong River has been reduced to fewer than 100 individuals, primarily due to entanglement in fishing nets. The Commission has supported WWF-Cambodia and the government of Cambodia in bringing experts on marine mammal health, demography, and behaviour to the country to assist them in assessing the threats to this population and developing conservation strategies and on-the-ground capability in the areas of science, law enforcement and health assessment. In January 2017, the Cambodian fisheries agency reported on progress in removing gillnets from the core zone of the Mekong River dolphins. Subsequent to this workshop the Commission partnered with the Chicago Zoological Society to bring a team of Mekong dolphin researchers to Sarasota Florida for two weeks of exchange and capacity building with the Sarasota Dolphin Research Program. This was overshadowed by news of the proposed construction of the Sambor and Stung Treng hydropower dams. If built, these dams will eliminate or transform most of the dolphins’ remaining riverine habitat. In March 2020 the Government of Cambodia announced the welcome news of a ten-year moratorium on dam construction on the Mekong River mainstem and a shift to a focus on other renewable energy resources. WWF convened a virtual Trinational Workshop in December 2020 to review conservation efforts for the three Irrawaddy dolphin populations in Cambodia, Indonesia, and Myanmar and to update recommendations for action on the Mekong, Mahakam, and Ayeyarwady Rivers.

South America

Commission representatives participating in the Scientific Committee of the International Whaling Commission have worked in the Sub-Committee on Small Cetaceans to draw attention to the impact of the use of meat from the two Amazonian freshwater cetacean species, the boto (Inia geoffrensis) and the tucuxi (Sotalia fluviatilis), for bait in the piracatinga catfish fishery. The government of Brazil responded to the recommendations of the Scientific Committee by placing a five-year ban on fishing for and marketing piracatinga in January 2015. Nevertheless there is strong evidence that the practice of using dolphins for bait continues and that much greater attention to this issue, and to other problems facing South American freshwater dolphins, is warranted.

Commission Reports and Publications

For more information on freshwater cetaceans, see Commission’s 2010–2011 annual report report and 2012 annual report.

Commission Letters

Letter Date Letter Description
August 21, 2017

Request for information regarding the endangered bajii/Chinese river dolphin/Yangtze River dolphin and endangered Saimaa subspecies of ringed seal for use in five-year status review under the ESA. 

April 26, 2016

Letter to National Marine Fisheries Service on Indus River dolphin 5-year status review under the Endangered Species Act

March 31, 2014

Letter to U.S. Ambassadors to Laos, Cambodia, Vietnam, and Thailand on the threat of hydropower dam construction to the critically endangered freshwater dolphins in the Mekong River

See also: Ambassador’s_response_letter

Learn More


The threats to freshwater cetaceans are diverse, longstanding, and difficult to assess and manage. Bycatch in fishing gear (entanglement or entrapment, usually leading to death) is the most serious and immediate problem for most populations, and gillnets are the greatest currently recognized cause of human-induced mortality. Freshwater cetaceans are also vulnerable to habitat modification and degradation (e.g., noise, chemical pollution, dams, lack of stream volume), and they compete with humans for prey. Vessel strikes, under-water explosions, the shock from electro-fishing, and entrapment in water management structures, notably irrigation canals, can cause injury or death. Some of these factors kill animals outright, and others impair their health or undermine their reproductive capabilities and social behavior. Unlike marine cetaceans, many freshwater animals live in environments where the very availability of water can be in doubt.

In freshwater (and estuarine) ecosystems, more so than in coastal or oceanic systems, such basic elements are finite and may be completely regulated, modified, or destroyed by human activities. The constricted nature of riverine habitat, and the inescapable need to share that habitat with humans, increases the vulnerability of these animals to bycatch in fisheries, overfishing of their prey, disturbance by noise, and being struck or displaced by vessels. In Brazil, Amazon River dolphins, or botos, and tucuxis are killed and used for bait in a fishery for a catfish, the piracatinga. Although most of the identified threats to freshwater cetaceans are widespread, and most freshwater cetacean populations face multiple threats, the types and intensity of human activities differ between different rivers. Nonetheless, in all cases, the human impact on river systems and on freshwater cetaceans is significant.

Current Conservation Efforts

The Commission continues its engagement on freshwater cetaceans both within the IWC’s Scientific Committee and through interactions with field researchers and conservationists in Asia and South America. The threats to freshwater cetaceans are ongoing and the impacts of human development need to be managed.

In 2017, the IWC formed the South Asian River Dolphin Task Team to assess the threats of habitat loss and bycatch to Ganges and Indus river dolphins. Scientists in India, Pakistan, and Nepal are working to coordinate efforts and develop a transnational plan to help conserve these species. The team is also working with the IWC’s Bycatch Mitigation Initiative to determine how future monitoring plans and alternative fishing gear technologies could reduce injury and death.

In 2021, the IWC adopted its first freshwater cetacean conservation management plan (CMP). The Amazon River Dolphin CMP was developed by the governments of Brazil, Colombia, Ecuador, and Peru. The plan outlines actions needed to assess dolphins range-wide and to identify and mitigate threats in the short and long term. The plan focuses on threats including deforestation, habitat fragmentation due to dams, mercury contamination, overfishing, bycatch, and climate change. It also focuses on using research to influence management and policy decisions. So far, over 45 botos have been tagged, mercury exposure and bycatch deterrent studies have been conducted, and a 2022-2023 workplan has been developed. Ongoing work includes determining how many species, subspecies, or subpopulations exist, identifying regional and national policies, and linking CMP goals with deforestation control.

Also in 2021, China passed a law to improve the protection and restoration of the Yangtze River basin. Many of the new measures will also promote the recovery of the Yangtze finless porpoise, including a ban on fishing in the Yangtze River and its tributaries for 10 years and a ban on the construction of chemical plants within 1km of the river. The IWC Scientific Committee recently highlighted the dire situation of the Yangtze finless porpoise which, without additional conservation efforts by the Chinese government, may follow the baiji to extinction in this heavily industrialized, densely populated river system.

In 2023, Cambodia’s prime minister ordered the creation of dolphin protection zones that prohibit fishing on the Mekong River. The Commission is encouraging further work on Irrawaddy dolphin conservation and behavior in the Mekong as enforcement efforts are strengthened there and is working to build support for efforts to understand and address threats to Irrawaddy dolphins in Myanmar and Indonesia.

Additional Resources

IUCN Tucuxi page

IUCN Boto page

IUCN Ganges River Dolphin page

IUCN Indus River Dolphin page

Indus River Dolphin 5-Year Review (2016)

IUCN Irrawaddy Dolphin page

IUCN Yangtze Finless Porpoise page

IUCN Baiji page