Introduction

Marine mammals (e.g., whales, dolphins, seals, polar bears) inhabit ocean ecosystems and directly influence the biology and functioning of those systems. Some marine mammals prey on fish and shellfish species. Others, such as sirenians (i.e., manatees and dugongs), graze on seagrasses and other submerged aquatic vegetation. Both activities structure marine ecosystems and impact the services those ecosystems provide to co-occurring species and coastal communities.

Marine mammals are vulnerable to numerous human-associated threats.¹ These threats have reduced marine mammals' populations over time and may lead to further impacts on their survival.² Activities that have affected marine mammal populations include historical whaling on various large whale species and incidental captures of marine mammals in fishing gear. In addition, marine mammals are at risk for injury or death associated with vessel strikes, poaching, harassment, pollution, and underwater acoustic sources.³ These risks are in addition to the effects of climate change on these species,⁴ including observed impacts to their prey sources, habitats, and migration patterns.⁵

Increases in the populations of some marine mammal species from previously declining levels have been observed in recent decades. Increases in observed populations include the eastern North Pacific gray whales, west Arctic bowhead whales, and a number of seal and sea otter populations.⁶ Despite certain observed population rebounds, marine mammals remain vulnerable to climate change and human-associated impacts, and some marine mammal populations remain low.⁷

Given past and emerging threats to marine mammal populations, and observed recoveries of certain species due in part to protection and conservation efforts, many stakeholders—including some in Congress—have prioritized the ongoing protection and conservation of these species. Some constituents have amplified concerns about threats to marine mammals because they are drawn to these aesthetic species. Others emphasize the economic importantance of these species and the need for ongoing protections; for example, marine mammal tourism is a valuable industry, with the whale-watching industry generating millions of dollars each year throughout U.S. coastal regions.⁸ Futhermore, experts also highlight and consider the ecosystem services these species provide. For example, large whales have been shown to enhance the productivity of ocean waters by bringing nitrogen and other nutrients to the surface (i.e., the whale pump) to support marine food webs and to sequester carbon dioxide from the atmosphere.⁹ Thus, marine mammal protection and conservation remain priorities, including in the context of management trade-offs with other ocean sectors.

Congress enacted the Marine Mammal Protection Act (MMPA) in 1972 (P.L. 92-522; 16 U.S.C. §§1361-1423h) to conserve all marine mammal populations and protect them from extinction or depletion as a result of human activities.¹⁰ Congress found that marine mammals should not be permitted to diminish below sustainable thresholds (i.e., below a population size at which they may replenish themselves effectively and continue functioning within their ecosystems).¹¹ The MMPA, as amended, contains five main provisions, each of which is codified as a separate title and subchapter in the legislation:

• Title I: Conservation and Protection of Marine Mammals. This title includes provisions with respect to ensuring sustainable population levels, minimizing impacts from fishing and non-fishing activities on marine mammals, accounting for marine mammal population status, and intergovernmental collaborations.
• Title II: Marine Mammal Commission (MMC). This title includes provisions for the establishment and functioning of the MMC.
• Title III: International Dolphin Conservation Program. This title includes provisions for the protection and conservation of dolphins and other marine mammals with respect to tuna fisheries. This title is not discussed in this report.
• Title IV: Marine Mammal Health and Stranding Response. This title includes provisions with respect to coordinating a marine mammal stranding network,¹² investigating and responding to unusual mortality events, administering marine mammal rescue assistance grant programs, and establishing a marine mammal health monitoring and analysis platform.
• Title V: Polar Bears. This title includes provisions regarding polar bear management, international agreements, and U.S. participation in the multilateral Agreement on the Conservation of Polar Bears.¹³ This title is not discussed in this report.

This report provides a brief overview of the MMPA, including its implementation by the National Oceanic and Atmospheric Administration (NOAA), U.S. Fish and Wildlife Service (FWS), and MMC. The report discusses selected provisions under certain titles, including provisions to (1) conserve and protect marine mammals to ensure they remain a sustainable, functional element in the ecosystem (Title I), (2) establish the MMC (Title II), and (3) create a marine mammal health and stranding response program (Title IV). The report is not organized to cover the MMPA in a section-by-section format under each title but rather with high-level summary information by theme and with corresponding nationally focused sections grouped accordingly. This report also provides a discussion of selected issues for Congress with respect to the MMPA, including considerations regarding climate change, ecosystem-based management, and trade-offs between marine mammal conservation and fisheries.

Purpose of the Marine Mammal Protection Act

The MMPA's aim is to prevent marine mammals and their populations from declining beyond the point where these species are no longer functioning elements of marine ecosystems. Specifically, declining beyond a population size at which marine mammals remain biologically meaningful and exert predatory controls or other ecological effects on other organisms.¹⁴ The MMPA defines a marine mammal as "any mammal which (A) is morphologically adapted to the marine environment (including sea otters and members of the orders Sirenia, Pinnipedia and Cetacea), or (B) primarily inhabits the marine environment (such as the polar bear); and, for the purposes of this chapter, includes any part of any such marine mammal, including its raw, dressed, or dyed fur or skin."¹⁵ The act declares that certain species and populations of marine mammals are in danger of extinction or depletion and that they should not be permitted to diminish below their optimum sustainable population (OSP),¹⁶ or beyond the point where they cease to be a significant functioning element in their particular ecosystem.¹⁷ The act's primary objectives for marine mammal management are to maintain the health and stability of the marine ecosystem and to maintain OSPs of marine mammals in consideration of a given habitat's carrying capacity.¹⁸ The act additionally focuses on measures to replenish any species or population that has already diminished below its OSP and to protect marine mammal essential habitats (and areas of similar significance for each species of marine mammal) from the adverse effects of human actions.¹⁹ Experts and stakeholders have referred to the recovery of multiple seal populations off New England and California—and increases in humpback, blue, and gray whales in recent decades—as evidence of the act's value.²⁰ Furthermore, the act emphasizes the importance of and need for marine mammal research and conservation.²¹

Implementation of the Marine Mammal Protection Act

Three federal agencies implement the MMPA, sharing responsibility for carrying out the act's conservation and management provisions:

• NOAA's National Marine Fisheries Service (NMFS; also known as NOAA Fisheries) is responsible for the protection of cetaceans and pinnipeds (other than walruses).²²
• FWS is responsible for the protection of walruses, sirenians, sea otters, and polar bears.²³
• The MMC, established in Title II of the MMPA,²⁴ provides independent, science-based administration of domestic and international policies and federal agency actions addressing human impacts on marine mammals and their ecosystems.²⁵

Additionally, NMFS and FWS have developed regulations to implement the MMPA, including for managing fishing and non-fishing impacts on marine mammals and regarding the import, export, and transportation of marine mammals.²⁶ MMC regulations also govern agency practices, compliance with other legislation, and public availability of agency materials.²⁷

Title I: Conservation and Protection of Marine Mammals

Title I of the MMPA contains the majority of the act's provisions that pertain to the conservation and protection of marine mammals.²⁸ Title I is organized into multiple sections that cover the following topics:

• The moratorium on taking and importing marine mammals and marine mammal products, including exemptions and issuance of permits
• Agencies that determine the status of marine mammal stocks and develop plans to conserve depleted stocks
• Regulations and administration of the MMPA
• Commercial fishing implications of the MMPA
• Domestic and international government engagements, research grants, and regional programs and provisions

The following sections primarily provide summaries of nationally centric elements under Title I of the MMPA. Title I also includes several regionally focused programs,²⁹ which are briefly described below (see "Regional Provisions").

Moratorium on Taking and Importing Marine Mammals and Marine Mammal Products

The MMPA established a moratorium on the taking of marine mammals in U.S. waters, except in certain cases.³⁰ The MMPA, under 16 U.S.C. §1362(13), defines take as "to harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or kill any marine mammal." Section 102 of the MMPA also prohibits any person or vessel under U.S. jurisdiction from taking or possessing any marine mammal on the high seas, except as provided for by an international treaty, convention, or agreement to which the United States is a party.³¹ These prohibitions extend to the transport, purchase, sale, or export of any marine mammal or marine mammal products, or any offers thereof unless explicitly permitted by NMFS or FWS (see "Permits and Other Specific Exemptions").³² The prohibitions additionally apply to any commercial fishing practices in violation of any regulations or limitations related to the conservation and protection of marine mammals issued for that fishery (see "Commercial Fishing and the MMPA").³³

The MMPA directs the Secretary of Commerce or the Secretary of the Interior (i.e., the Secretary)³⁴ to issue regulations carrying into effect the prohibitions in MMPA on the taking and importing of marine mammals. In promulgating regulations, the Secretary must use "the best scientific evidence available" and consult with the MMC.³⁵ Regulations are to be periodically reviewed and may be modified at the Secretary's discretion.³⁶ The Secretary is to account fully for multiple factors when prescribing these regulations, including the existing and future levels of marine mammal species and their populations; international treaties and agreements; the marine ecosystem; and fisheries, economic, and technological considerations.³⁷

Authorizations, Permits, and Specific Exemptions

The MMPA includes specific requirements and allowable exemptions (e.g., for subsistence uses by Alaska Natives) related to the moratorium. It also grants authority to the Secretary to allow the taking of marine mammals or issue permits for certain activities that involve marine mammals.³⁸ For example, the MMPA includes provisions for the authorized incidental taking (i.e., taking that is infrequent, unavoidable, unexpected, or accidental and that causes negligible impact)³⁹ of marine mammals during commercial fishing operations (see "Taking of Marine Mammals Incidental to Commercial Fishing Operations"),⁴⁰ as well as during non-fishing activities (e.g., offshore energy exploration).⁴¹ Table 1 includes information about the different types of authorizations issued by federal agencies for incidental takes (e.g., an incidental take authorization) or directed takes (i.e., a specific permit to allow for an intentional interaction under a specific purpose that may result in take) of marine mammals during specific activities. Further information is provided in the below sections.⁴²

Incidental Take Authorizations

The MMPA and its implementing regulations give NOAA and FWS the authority to authorize incidental takes of small numbers of marine mammals within a specified geographic region during particular non-fishing oceanic activities.⁴³ Additionally, the MMPA allows the Secretary to issue permits allowing for marine mammals to be taken incidentally during military readiness activities.⁴⁴ Authorization of incidental takes from the relevant agency to a given party is provided through an incidental take authorization. There are two types of these authorizations:

• 1. An Incidental Harassment Authorization (IHA), which may be issued for small-scale activities or activities expected to result only in harassment of marine mammals.
  
  The MMPA further defines harassment as "any act of pursuit, torment, or annoyance which—(i) has the potential to injure a marine mammal or marine mammal stock in the wild; or (ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering."⁴⁵
  
  The MMPA and its implementing agencies categorize harassment as Level A harassment, which has the potential to cause a permanent threshold shift or other types of nonserious injury,⁴⁶ and Level B harassment, which has the potential to disturb marine mammals and disrupt their behavioral patterns.⁴⁷
• 2. Letter of Authorization (NOAA, FWS) and/or Incidental Take Regulation (FWS) for larger-scale activities or activities that may cause serious injury or mortality to marine mammals.⁴⁸ NOAA and FWS also publish specific regulations related to these authorized takes, in consultation with the MMC.⁴⁹
  
  Incidental Take Authorizations are issued to applicants following review by NOAA or FWS and notice and opportunity for public comment in the Federal Register.⁵⁰ When issuing authorizations, the agency typically works with applicants to define appropriate monitoring and mitigation measures for minimizing adverse effects on marine mammals.⁵¹

Permits and Other Specific Exemptions

The Secretary also may issue a permit that exempts activities from the moratorium on taking and importing marine mammals during the following actions, as specified in Sections 101 and 104:

• Scientific research, public display, or enhancing the survival or recovery of a species.⁵²
• Photography for educational or commercial purposes.⁵³
• Importing polar bear parts taken in sport hunts in Canada.⁵⁴

These permits may be issued if the proposed taking or importation is reviewed by the MMC and the Committee of Scientific Advisors on Marine Mammals (see the text box on the MMC for more information about the committee).⁵⁵ The Secretary is to publish a public notice of each application made for a permit, and to invite written data or views from interested parties with respect to the taking or importation proposed in that application, before any decision to issue a permit.⁵⁶ The Secretary also may modify, suspend, or revoke any issued permit.⁵⁷

In addition, the MMPA includes exemptions (i.e., those that do not require a permit) for marine mammal takes performed in self-defense or national defense,⁵⁸ for ensuring the health and survival of a marine mammal (i.e., "Good Samaritan exemption),⁵⁹ and for takes associated with Alaska Native subsistence activities or for creating and selling authentic Native articles of handicrafts and clothing.⁶⁰

Penalties for Taking or Possessing a Marine Mammal

Section 105 of the MMPA states that the Secretary may assess a civil penalty (i.e., a fine) to any person who violates any provision, permit, or regulation after notice and opportunity for a hearing.⁶¹ Additionally, as included in Section 106, any vessel or other conveyance subject to U.S. jurisdiction that is employed in any manner in the unlawful taking of any marine mammal shall have its entire cargo or the monetary value thereof subject to seizure and forfeiture and liable for any civil penalties issued by a district court.⁶² As stipulated in Section 107, the Secretary enforces all MMPA provisions related to Title I and may designate officers and employees of any U.S. state or territory to enforce these provisions.⁶³

Marine Mammal Status Determinations, Stock Assessments, and Conservation Plans

Status determinations for marine mammals (i.e., depleted or not depleted) are necessary for understanding the sustainability of these species and any potential threats to the viability of their populations. Assessments of marine mammal populations (i.e., stock assessments) provide information on population trends, productivity rates, and estimates of mortality and serious injury to inform status determinations.⁶⁴ This information allows federal agencies to evaluate the effectiveness of conservation and protection measures and to adjust management approaches as necessary.⁶⁵

Status Determinations

The MMPA, under Section 115, requires the Secretary to determine the status of a marine mammal species or stock (i.e., whether it is depleted or should no longer be designated as such) through the issuance of a rule after notice and opportunity for public comment.⁶⁶ The Secretary may independently initiate a determination or may do so in response to a petition for a status review.⁶⁷ The Secretary is to make any determination based on the best scientific information available, including as conducted through a stock assessment, and may publish a call for scientific information from individuals, organizations, institutions, or informal working groups.⁶⁸ For example, NOAA evaluates the status of marine mammal stocks with respect to whether a stock is depleted as defined under statute, its status relative to OSP (i.e., within OSP, below OSP, or unknown), its designation as strategic or not, its status relative to the MMPA "zero mortality goal," and based on a summary of trends in abundance and human-caused mortality and serious injury.⁶⁹ In addition to those stocks determined to be depleted through population assessments, MMPA provisions identify any marine mammal population that is listed under the ESA as depleted.⁷⁰ As of November 2023, 51 domestic and foreign marine mammal stocks were listed as depleted.⁷¹

Stock Assessments

The Secretary conducts stock assessments of marine mammals to evaluate the status of each stock in U.S. waters, as required by the MMPA.⁷² The assessment for each marine mammal contains scientific information on its geographic range, trends in abundance, population structure, human-caused mortality and serious injury, interactions with commercial fisheries,⁷³ and additional threats.⁷⁴ Each assessment is to determine whether a given marine mammal stock (1) has a level of human-caused mortality and serious injury unlikely to cause the stock to be reduced below its OSP or (2) is determined to be a strategic stock, including a description of the reasons for that classification.⁷⁵ Regional Scientific Review Groups (SRGs) advise the Secretary on these assessments.⁷⁶

The MMPA defines a strategic stock as a marine mammal population that is listed, or likely to be listed, as a threatened or endangered species under the ESA or for which direct human-caused mortality is greater than its potential biological removal level (PBRL).⁷⁷ The term strategic stock also includes those stocks that are designated as depleted under the MMPA.⁷⁸

The MMPA defines PBRL as the maximum number of animals, not including natural mortalities, that may be removed from the population while allowing it to reach or maintain its OSP.⁷⁹ Thus, the PBRL is a direct measure of the maximum allowable mortalities from human activities that may occur to that marine mammal stock to keep its population at sustainable levels.

The goal of a stock assessment is to estimate the PBRL for the stock, including a description of the information used to calculate this level and the recovery factor.⁸⁰

The Secretary is to review stock assessments annually for strategic stocks and those for which significant new information is available, and at least once every three years for all other stocks.⁸¹ If the status for a given stock has changed or can be more accurately determined, then the Secretary is to revise the stock assessment following SRG advice and considering public comment.⁸² The Secretary is to make available all draft stock assessments, or any revisions thereof, for public comment over a 90-day period.⁸³ Additionally, the Secretary is to consider the best scientific information available, the advice of the appropriate regional SRG, and public comments before issuing any final stock assessments.⁸⁴ Section 117 gives authority to the Secretary of Commerce, in consultation with the Secretary of the Interior, MMC, and other parties, to establish three independent regional SRGs representing the Alaskan, Pacific (including Hawaii and Pacific Island territories), and Atlantic (including the Gulf of Mexico) regions.⁸⁵

NOAA and FWS have conducted marine mammal stock assessments since 1995.⁸⁶ Figure 1 includes trends in the percentages of strategic marine mammal stocks (i.e., out of the total number of marine mammal stocks) that have been identified in annual stock assessment reports. The percentage of strategic stocks in a given region indicates how many relative stocks exist where human-caused mortality exceeds the PBRL or are below OSP, which can indicate the effectiveness of the MMPA as implemented.⁸⁷ Over time, the highest percentage of strategic stocks have consistently occurred in the Atlantic region (including Gulf of Mexico and U.S. Caribbean stocks), with decreases observed from the 1990s to mid-2000s. Increases in the percentages of strategic stocks were observed for the Alaskan region since the 1990s, while less pronounced decreases occurred in the Pacific region over time. The trends for all three regions generally have remained consistent since the 2010s, with occasional fluctuations occurring for Alaskan and Atlantic stocks. Declines in the percentages of Atlantic strategic stocks over time, and of Pacific stocks to a lesser extent, suggest effectiveness of MMPA protection and conservation efforts in those regions. Furthermore, increases in percentages of Alaskan strategic stocks during the 1990s and 2000s could suggest lower effectiveness of these efforts or the presence of other factors (e.g., climate, environmental, and human-associated stressors) differentially affecting Alaskan marine mammal populations.⁸⁸ However, consistency of strategic stock percentages in more recent decades also may suggest consistency in MMPA effectiveness among regions, as noted in one study.⁸⁹

Figure 1. Percentage of Strategic Marine Mammal Stocks in U.S. Regions over Time

Sources: National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service, "Marine Mammal Stock Assessment Reports by Region," https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region; U.S. Fish and Wildlife Service (FWS), "Marine Mammal Stock Assessment Reports," https://www.fws.gov/project/marine-mammal-stock-assessment-reports. Notes: Data are shown for the percentage of marine mammals identified as strategic stocks in NOAA and FWS marine mammal stock assessment reports. Years for which data are not shown reflect that no stock assessment was conducted for that region during that year. Data from NOAA and FWS stock assessment reports are combined for years 2022 and 2023 given different agency reporting schedules for those years. The Alaskan region includes all marine mammals in state and federal waters of the State of Alaska. The Atlantic region includes all marine mammals in U.S. state and federal waters off the Atlantic coast, northern Gulf of Mexico, and Caribbean regions. The Pacific region includes all marine mammals in U.S. state and federal waters off the U.S. West Coast and Pacific Island territories.

Conservation Plans and Requirements

The MMPA mandates the Secretary to take action for those stocks that it determines to be depleted (i.e., below its OSP or listed under the Endangered Species Act [16 U.S.C. §§1531-1544]). The MMPA, under Section 115, requires the Secretary to prepare conservation plans for any species or stock designated as depleted unless the Secretary determines that doing so would not promote that species' or stock's conservation.⁹⁰ The MMC also may provide recommendations for conservation plans.⁹¹ The purpose of each plan is to conserve and restore the species or stock to its OSP.⁹²

The Secretary also may determine that a take reduction plan is necessary to reduce the incidental taking of marine mammals in the course of commercial fishing operations from a strategic stock or for species or stocks that are affected by a commercial fishery.⁹³ If so, any conservation plan also is to incorporate that take reduction plan for that species or stock.

The MMPA defines take reduction plan as a plan that is designed to assist in the recovery of or prevent the depletion of each strategic stock that is affected by a commercial fishery that is included in the Secretary's list of commercial fisheries (see "Commercial Fishing and the MMPA" and "Take Reduction Plans" for more information).⁹⁴

Administration, Regulations, and Program Reviews

The MMPA grants authority for the Secretary to engage with other federal agencies through multiple means to carry out the requirements of the MMPA. The Secretary collaborates with other federal agencies to implement provisions of the MMPA; conduct marine mammal program reviews; and issue measures, including those focused on lowering effects on strategic stocks.⁹⁵ For example, NMFS regulations state that the Secretary of Commerce may "utilize, by agreement, the personnel, services, and facilities of any other Federal Agency for the purposes of enforcing this MMPA."⁹⁶

Additionally, under the MMPA, the Secretary is required to review annually the operation of each U.S. participatory program that involves the taking of marine mammals.⁹⁷ In the context of the MMPA, a program may include activities and responsibilities administered by federal agencies with respect to marine mammal protection and conservation. The Secretary may suspend the operation of a program that cannot be administered in the United States or in accordance with the MMPA and is to inform the public and Congress about the reasons for any suspension.⁹⁸ The Secretary also is to include any legislative recommendations for resolving the issues leading to suspension of the program.⁹⁹ Furthermore, if the Secretary determines that impacts to marine mammal habitats may be causing the decline or impeding the recovery of a strategic stock, the Secretary "may develop and implement conservation or management measures to alleviate those impacts."¹⁰⁰

Commercial Fishing and the MMPA

The MMPA contains requirements that address the conservation of marine mammals for commercial fishing operations. These requirements include limiting incidental takes during fishing;¹⁰¹ developing and devising commercial fisheries gear and commercial fishing practices to minimize incidental takes;¹⁰² and granting take exemptions for commercial fisheries under certain circumstances.¹⁰³

Taking of Marine Mammals Incidental to Commercial Fishing Operations

Section 118 of the MMPA prohibits the intentional lethal take of any marine mammal in the course of commercial fishing operations.¹⁰⁴ Section 118 also governs the incidental taking of marine mammals during commercial fishing operations of U.S. permitted vessels, including the goal of reducing incidental marine mammal mortality to insignificant levels (i.e., approaching a zero mortality and serious injury rate).¹⁰⁵ NMFS regulations further state that any incidental kill or incidental serious injury of marine mammals permitted during commercial fishing operations is to be reduced to those levels.¹⁰⁶

The MMPA directs the Secretary of Commerce to publish an annual list of commercial fisheries, for which different degrees of marine mammal incidental takes are associated.¹⁰⁷ These include Category I fisheries, which are associated with frequent incidental takes; Category II fisheries, in which occasional incidental taking occurs; and Category III fisheries, which have a remote likelihood of or no known incidental taking of marine mammals.¹⁰⁸ In the 2023 annual list of commercial fisheries, examples of Category I fisheries include Hawaiian deep-set longline fisheries,¹⁰⁹ which are known to affect multiple species of dolphins and whales, and Northeast/Mid-Atlantic American lobster trap/pot fisheries, which affect multiple dolphin and porpoise populations as well as seals and whales.¹¹⁰ An example of a Category II fishery is the Alaska Bering Sea and Aleutian Islands pollock trawl fishery, which affects several species of seals, Steller sea lion, humpback whales, and Pacific white-sided dolphin.¹¹¹ The Gulf of Maine Atlantic herring purse seine fishery, which affects the harbor seal, is an example of a Category III fishery.¹¹²

Section 118 states that the Secretary may grant a marine mammal authorization to a registered vessel engaged in a Category I or II listed fishery upon receipt of a completed registration form.¹¹³ The Secretary of Commerce may suspend or revoke an authorization and may charge fees for those authorizations.¹¹⁴ Furthermore, any vessel owner engaged in a Category I or II fishery who fails to obtain and maintain a current marine mammal authorization is in violation of the MMPA.¹¹⁵ Additionally, the Secretary of Commerce is to monitor the incidental mortality and serious injury of marine mammals during the course of commercial fishing operations, including through an on-board observer, as may be required by the Secretary of Commerce as a condition of an authorization.¹¹⁶ Any commercial fishing vessel owner or operator is to report to the Secretary of Commerce all incidental mortalities and injuries of marine mammals in the course of commercial fishing operations.¹¹⁷

Take Reduction Plans

The MMPA includes provisions to address commercial fishery interactions with strategic marine mammal stocks. The Secretary of Commerce is to develop and implement a take reduction plan to protect or restore a marine mammal population, as included in Section 118 of the MMPA.¹¹⁸ Take reduction plans are designed to assist in the recovery of, or prevent the depletion of, each strategic stock that interacts with a Category I or II commercial fishery.¹¹⁹ Additionally, these plans can be created for any other marine mammal stocks that interact with a Category I commercial fishery.¹²⁰ Take reduction plans are intended to reduce the incidental mortality or serious injury of a strategic stock during commercial fishing to levels less than its determined PBRL.¹²¹ The plan's immediate goal is to reduce those levels to less than the PBRL within six months of its implementation, with a long-term goal of reducing them to insignificant levels reaching a zero mortality and serious injury rate.¹²²

Each take reduction plan is to include

• information in the final stock assessment for that marine mammal population, and any substantial new information;
• an estimate of the total number of animals from that stock that are incidentally lethally taken or seriously injured each year during commercial fishing, including their age and gender if possible;
• recommended regulatory or voluntary measures to reduce incidental mortality and serious injury; and
• recommended dates to achieve the specific plan objectives.¹²³

The Secretary may request a take reduction team to address a single stock that interacts with a given fishery, a stock that extends over one or more regions or fisheries, or multiple stocks within a region or fishery.¹²⁴ For example, the Atlantic Large Whale Take Reduction Team addresses North Atlantic right whales, humpback whales, and fin whales covered under the Atlantic Large Whale Take Reduction Plan (ALWTRP), including the whales' interactions with trap and pot gears and gillnets.¹²⁵

The Secretary may issue emergency regulations if he or she finds the incidental mortality and serious injury of marine mammals is having, or is likely to have, an immediate and significant adverse impact on a marine mammal stock, including those with take reduction plans.¹²⁶ The Secretary is to consult with the MMC, all appropriate FMCs, state fishery managers, and the appropriate Take Reduction Team, if one is established, regarding these regulations.¹²⁷ These regulations may apply to a species with a take reduction plan in effect, a take reduction plan in development, or for a stock or species for which a take reduction plan does not exist and is not being developed.¹²⁸ For example, in February 2023, NMFS extended a 2022 temporary emergency rule under the ALWTRP to prohibit the use of buoy lines between federal and state waters within the Massachusetts Restricted Area through April 2023.¹²⁹ This action was taken to reduce the threat of incidental mortality and serious injury to North Atlantic right whales from lobster and Jonah crab trap/pot fisheries, for which there is a high risk of overlap and entanglement.¹³⁰ There has been litigation related to this issue.¹³¹

Commercial Fisheries Gear Development and Marine Mammal Research Grants

The MMPA includes provisions aimed at reducing incidental takes of marine mammals in fishing gear through multiple means. The Secretary of Commerce is authorized to undertake a research and development (R&D) program to devise fishing methods and develop gear to reduce the incidental take of marine mammals by commercial fishing.¹³² The Secretary of Commerce, after consultation with the MMC, also is to issue regulations to reduce that incidental taking to the lowest practicable level; these regulations are to account for any research results from the R&D program.¹³³ For example, the ALWTRP includes gear making requirements for lobster and Jonah crab traps/pots with respect to markings, colors, buoy lines, breaking strengths of ropes and other gear links, and other measures to minimize effects on whales.¹³⁴ Agents of the Secretary of Commerce are authorized to board and accompany any commercial fishing vessel to conduct research and observe operations that assist in the development of improved fishing methods and gear.¹³⁵

Section 110 of the MMPA also authorizes the Secretary to make marine mammal research grants, or to provide financial assistance for research into new methods of locating and catching yellowfin tuna without incidental taking of marine mammals.¹³⁶ The Secretary may provide these funds following review by the MMC.¹³⁷

Federal-State Engagements, International Agreements, and Regional Provisions

The MMPA directs the Secretary to cooperate with states and to participate in proceedings under international marine mammal protection and conservation agreements.¹³⁸

Federal Cooperation with States

All marine mammals in U.S. waters are managed under federal jurisdiction.¹³⁹ Section 109 mandates that no state may enforce, or attempt to enforce, any state law or regulation related to the taking of marine mammals within the state unless the Secretary has transferred authority for the conservation and management of that species to that state.¹⁴⁰ Congress authorized the Secretary to transfer the authority for the conservation and management of marine mammals to a state where the species inhabits.¹⁴¹ This transfer allows the state to enforce any state law or regulation related to the taking of marine mammals, which is to be consistent with federal law.¹⁴²

Certain Hawaiian marine mammals, such as Hawaiian monk seals, humpback whales, and several species of dolphins, also remain protected under Hawaii state laws.¹⁴³ The State of Hawaii Department of Land and Natural Resources (HDLNR) regulated Hawaiian monk seals and other marine mammals prior to the enactment of the MMPA and the ESA, after which the management of Hawaiian marine mammals became a federal responsibility.¹⁴⁴ HDLNR retained its management responsibilities, including for those species included under federal acts, as included under Hawaii state laws.¹⁴⁵

International Agreements

The MMPA authorizes the Secretary, through the Secretary of State, to initiate negotiations with other countries to develop bilateral or multilateral international agreements for the protection and conservation of marine mammals.¹⁴⁶ Further, the Secretaries are to initiate negotiations with foreign governments that are engaged in commercial fishing operations detrimental to any species or stock of marine mammal and work to enter into treaties with those countries to protect marine mammals, among other duties.¹⁴⁷ The MMPA provisions are deemed to be in addition to, and not in contravention of, the provisions of any existing international treaty, convention, agreement, or statute that applies to the taking of marine mammals.¹⁴⁸

Regional Provisions

The MMPA includes regional provisions, where Congress has directed the Secretary of Commerce to examine marine mammals in the context of regional ecosystems.¹⁴⁹ The act also includes provisions regarding marine mammal cooperative agreements in Alaska and for two regional task forces that investigate areas with pinniped-fishery interactions.¹⁵⁰ Information regarding these regional studies and efforts is briefly summarized below:

• Section 110 of the MMPA directed concurrent investigations and research program development into the roles and conservation of marine mammals in the Gulf of Maine ecosystem,¹⁵¹ and for the Bering Sea ecosystem.¹⁵²
• Section 119 includes provisions with respect to marine mammal cooperative agreements in Alaska.¹⁵³
• Section 120 includes provisions with respect to the Pacific Coast and Gulf of Maine Task Forces, which are tasked to investigate pinniped-fishery interactions.¹⁵⁴

Title IV: Marine Mammal Health and Stranding Response

Congress authorized the Marine Mammal Health and Stranding Response Program (MMHSRP) in the 1992 amendments to the MMPA to account for marine mammal stranding events.¹⁵⁵ The MMPA, under Title IV, mandates the Secretary of Commerce to establish the MMHSRP in consultation with the Secretary of the Interior, the MMC, individuals with knowledge and experience in (1) marine science, (2) marine mammal science, (3) marine mammal veterinary and husbandry practices, and (4) marine conservation, including stranding network participants.¹⁵⁶

As prescribed in the MMPA, the program is to

• facilitate the collection and dissemination of reference data on the health of marine mammals and health trends of wild marine mammal populations;
• correlate the health of marine mammals and their wild populations with available data on physical, chemical, and biological environmental parameters; and
• coordinate responses to unusual mortality events (UMEs) by establishing a process in the Department of Commerce.¹⁵⁷

The MMHSRP works with volunteer stranding and entanglement networks and with local, tribal, state, and federal government agencies to coordinate and conduct emergency responses to stranded or entangled marine mammals, including for UMEs (see "Unusual Mortality Events").¹⁵⁸ The program provides standing network members with a stranding agreement from the NMFS regional offices to ensure all activities are performed in consideration of the safety of both responders and marine mammals.¹⁵⁹ Network participants provide staff and local response capabilities, and they independently raise funds to cover the majority of their costs.¹⁶⁰ The Secretary of Commerce, in consultation with the Secretary of the Interior, also is to collect and periodically update existing information on procedures, practices, and criteria for rescuing and rehabilitating stranded or entangled marine mammals.¹⁶¹ Each stranding network participant that responds to a given stranding or entanglement is to submit data regarding the stranding to the NOAA Administrator or the FWS Director.¹⁶² The Secretary is to make that information available to researchers, stranding network participants, and the public.¹⁶³

The MMPA also stipulates that the Secretary is to "make provision for the storage, preparation, examination, and archiving of marine mammal tissues" in the National Marine Mammal Tissue Bank and to issue guidance for the tissue bank's operations.¹⁶⁴ In addition to tissues taken during UMEs, the tissue bank is to include tissue samples from other sources in the wild, including samples from marine mammals taken incidental to commercial fishing operations, for subsistence purposes, biopsy samples, and any other samples collected in accordance with tissue bank standards.¹⁶⁵ The Secretary also is to maintain a central, publicly accessible database with that information.¹⁶⁶ Title IV of the MMPA established the John H. Prescott Marine Mammal Rescue and Response Grant Program and the John R. Geraci Marine Mammal Rescue and Rapid Response Fund for emergency assistance in cases outside of a UME.¹⁶⁷ The Secretary may grant emergency financial assistance for stranding events or entanglements that occur to marine mammals under the Secretary's jurisdiction.¹⁶⁸

Unusual Mortality Events

The MMPA requires the Secretary of Commerce to consult with the Secretary of the Interior during all mandated activities regarding unusual mortality events (UMEs),¹⁶⁹ including in the establishment of a marine mammal UME working group consisting of experts who provide guidance for

• determining whether a UME is occurring;
• determining if response actions to a given UME are no longer necessary after a UME has begun; and
• developing a contingency plan to assist the Secretary in responding to UMEs.¹⁷⁰

The Secretary, after receiving notification from a stranding network participant that a UME might be occurring, is to contact as many members of the UME working group as possible for guidance within 24 hours post-notification.¹⁷¹ Within 48 hours post-notification, the Secretary is to make a determination as to whether a UME is occurring, inform the stranding network of that determination, and designate one or more onsite coordinators for the event (i.e., one or more appropriate regional directors of the National Marine Fisheries Service [NMFS] or the U.S. Fish and Wildlife Service, or their designees) if the Secretary determines that a UME is occurring.¹⁷² The onsite coordinator is to make immediate recommendations to stranding network participants on how to proceed with response activities and to coordinate and direct the activities of all persons responding to a UME.¹⁷³

The Secretary of Commerce is to issue a detailed contingency plan for responding to any UME in consultation with the Secretary of the Interior and the UME working group.¹⁷⁴ The plan is to include information regarding contacts for responding to a UME; tissues and analyses needed for diagnosing UME causes; necessary training, mobilization, and other procedures; and requirements needed to minimize death and provide appropriate care for marine mammals, among other contents.¹⁷⁵

The MMPA also established the Marine Mammal Unusual Mortality Event Fund in the U.S. Treasury.¹⁷⁶ This fund serves to make advance, partial, or progress payments for costs incurred in response to a UME; for reimbursing any stranding network participants for costs incurred in the collection, preparation, analysis, and transportation of marine mammal tissues and samples collected during a UME for the National Marine Mammal Tissue Bank; and for the care and maintenance of a marine mammal.¹⁷⁷ The Secretary also may accept, solicit, and use the services of volunteers and accept and may solicit donations for this fund.¹⁷⁸

Issues and Options for Congress

Congress and stakeholders have commented on the effectiveness of the MMPA since its enactment in 1972. Congress last passed comprehensive amendments in 1994 (P.L. 103-238) and has only slightly amended certain provisions since then. Some stakeholders have raised concerns regarding how current law may address recent and emerging threats to marine mammals, such as climate change.¹⁷⁹ Other experts and stakeholders have considered if and how MMPA provisions align with holistic ecosystem-based management efforts.¹⁸⁰ Fishers and those from other marine sectors have raised concerns about trade-offs among marine mammal conservation efforts, species recovery, and impacts on marine fisheries. If Congress seeks to address any of these potential issues, several options could be considered. These options include oversight of certain agency activities, including directing studies to inform consideration of changes in implementing the MMPA. These issues and potential options related to the authorization elements of the MMPA are discussed below.

Climate Change and the Marine Mammal Protection Act

Climate change can affect multiple aspects of aquatic and terrestrial ecosystems that support marine mammals. For example, studies have attributed polar bear habitat loss, increased disease proliferation in marine mammals, and greater incidence of harmful algal bloom toxins in north Pacific seals and walruses to climate change.¹⁸¹ Additionally, experts suggest that increased predation on southern sea otters has resulted from northward distribution shifts of white sharks associated with warming ocean temperatures.¹⁸² Furthermore, changes in whale migration routes and timing at feeding grounds may be related to ocean warming, shifts in prey resources, loss of sea ice, and changes in upwelling intensity.¹⁸³ Arctic sea ice loss has also led to reductions in polar bear marine foraging habitat, lowered energetic diet from greater reliance on terrestrial food sources, and altered foraging and rearing habitats for narwhals and multiple species of pinnipeds, including Pacific walrus.¹⁸⁴

Researchers, certain stakeholders, and some in Congress have raised concerns regarding marine mammals' vulnerability to climate change, including how the present framework in the MMPA may address the effect of climate change on these species.¹⁸⁵ Some stakeholders have petitioned for the MMPA to evolve beyond focusing on threats from human actions to addressing emerging threats to marine mammal conservation and "long-term chronic threats" such as global climate change.¹⁸⁶ They have noted that refinements to the MMPA or additional legislation similar to the MMPA are important, given these ongoing threats.¹⁸⁷ Others point out that the MMPA as written currently requires agencies to develop programs to minimize threats to marine mammals but does not explicitly include indirect threats such as climate change.¹⁸⁸ They also note that certain programs currently collect and incorporate data regarding inferred impacts on marine mammals from human-induced climate change, which could suggest that amendments to statutory language may not be necessary.¹⁸⁹

If Congress chooses to address the MMPA in the context of climate change, one option would be to consider amending the statute or providing direction to the Secretary to implement certain activities. For example, H.R. 1383, introduced in the 118^th Congress, proposes amending the MMPA to include requirements for protecting marine mammals adversely affected by climate change and would establish a program within NOAA to monitor those adverse impacts to marine mammals.¹⁹⁰ The bill also would require NMFS and FWS to issue regulations that list U.S. marine mammal species for which climate change is likely to result in a decline in population abundance, impeded population recovery, or reduced carrying capacity. These regulations would include climate impact management plans for listed species. Furthermore, the bill would direct NMFS and FWS to review agreements with foreign governments concerning the management of marine mammals that are or may be affected by climate change and would direct the Department of State to initiate amendments to those agreements or negotiate their development.

H.R. 3764, introduced in the 117^th Congress, proposed establishing various requirements to protect marine mammals from climate change and other threats. Title VII of the bill, "Strengthening Marine Mammal Conservation," would have added a new section to Title I of the MMPA to include a list of marine mammal species expected to be adversely affected by climate change and for federal climate impact plans. The bill would have required NOAA to monitor climate impacts on marine mammals and the Secretary to consider adverse climate impacts when estimating PBRL. At a House Committee on Natural Resources hearing in June 2021, both FWS and NOAA testified in support of this bill and expressed that it aligned with agency priorities at the time.¹⁹¹ Both agencies recommended incorporating the climate impact plan requirements into existing plans and minimizing duplicative approaches for marine mammal conservation.¹⁹²

As an alternative approach, Congress could choose to retain the present language in the MMPA and other corresponding legislation. This approach would allow agencies to address marine mammal management within the constraints of existing authorities, which some argue may already allow for addressing certain climate change impacts.¹⁹³ Some Members of Congress have expressed concerns about provisions in H.R. 3692, introduced in the 117^th Congress, regarding new federal agency consultation requirements for MMPA amendments for marine mammal climate impact management plans. Some Members and stakeholders have questioned whether these additional requirements and consultation timeframes would lead to delays in activities adjacent to waterways.¹⁹⁴ Some Members also have raised concerns about the accuracy of marine mammal population projections that may inform the list of marine mammals proposed in H.R. 3764.¹⁹⁵

Ecosystem-Based Management and the MMPA

The MMPA includes multiple references to the importance of marine mammals as functioning elements in the ecosystems of which they are part and stipulates that the management of these species is to focus on maintaining the health and stability of the marine ecosystem.¹⁹⁶ Since the MMPA's enactment, federal agencies have implemented ecosystem management approaches that consider multiple ocean sectors and living marine resources and have conducted integrated assessments to inform these practices.¹⁹⁷

Stakeholders and federal agencies have noted that the MMPA was the first legislation to mandate an ecosystem-based approach to managing marine resources.¹⁹⁸ NOAA has emphasized that the MMPA shifted the focus of conservation from species to ecosystems and included protection for population stocks, species, and subspecies.¹⁹⁹ NOAA and partners also note that the MMPA shifted the burden of proof from resource managers to resource users to show that any proposed impacts on marine mammals would not adversely affect the resource or the ecosystem.²⁰⁰

MMPA provisions currently account for the effects of human activities on marine mammals and their incidental takes; however, some experts and stakeholders have raised concerns about the scope of current management approaches and their ability to effectively manage multiple marine mammal stressors.²⁰¹ For example, some stakeholders have acknowledged the increasing complexities of marine mammal threats and have noted that the management of interacting environmental factors and ocean sectors warrants further consideration in the MMPA.²⁰² Alternatively, other stakeholders have expressed concerns about the complexity, costs, and administrative challenges associated with ecosystem-based management approaches.²⁰³

If Congress chooses to consider a legislative approach to address multiple human ocean uses and marine mammals in concert, one option would be to amend the MMPA to focus on addressing the cumulative effects of multiple stressors from human activities on marine mammals. For example, H.R. 3764, introduced in the 117^th Congress, would have amended the MMPA to include provisions for mitigating the effects of vessel traffic and included additional provisions related to monitoring and mitigating ocean noise effects on marine mammals.

As an alternative approach, Congress may decide to retain the present statute and direct agencies through appropriations or oversight activities that focus on the effects of specific ocean uses or sectors on marine mammals. For example, Congress provided appropriations to NMFS for offshore wind energy expansions and protected species needs, including marine mammals, as specified in the explanatory statements for the Consolidated Appropriations Act, 2022 (P.L. 117-103), and Consolidated Appropriations Act, 2023 (P.L. 117-328).²⁰⁴ Congress directed NOAA in the FY2023 explanatory statement to address "consultation and permitting, stock assessment, management, and protected resources needs related to the expansion of offshore wind energy projects."²⁰⁵ Congress also could consider additional oversight like that in H.R. 1056. during the 118^th Congress. As introduced, H.R. 1056 would direct the comptroller general to conduct a study to assess the sufficiency of the environmental review process for offshore wind projects, including in consideration of impacts to whales, finfish, and other marine mammals. Such studies could inform the options and consequences of amending the MMPA regarding its interactions with specific sector activities. Alternatively, Congress may direct agencies to assess cumulative stressors from human activities and environmental phenomena on marine mammals through approaches recommended by experts, which may inform ecosystem-based management.²⁰⁶ Congress also may opt to retain current approaches as defined in the MMPA and leave additional considerations regarding marine mammal interactions with ocean sectors to the discretion of particular agencies.

Trade-Offs Between Marine Mammal Conservation and Fisheries

Trade-offs between MMPA-implemented conservation and protection efforts and their impacts on commercial fishing operations have been a regular issue of concern for some Members of Congress and stakeholders. For example, the use of emergency actions, gear regulations, and fishing closures to limit commercial fishing impacts on large whales has generated attention in recent years, including economic considerations for fishers.²⁰⁷ Some stakeholders perceive these actions as overreaching and too restrictive for fishers, whereas others emphasize the necessity of these actions or argue for increased protection.²⁰⁸ Some experts also suggest that underfishing (i.e., fishing below optimal levels) may result from certain fishing regulations associated with marine mammal conservation requirements in the MMPA.²⁰⁹ Additionally, prohibitions and protections mandated by the MMPA have led to rebounds in some marine mammal populations (e.g., seals, sea lions) and have caused some stakeholders to raise concerns about heightened marine mammal predation on fisheries species.²¹⁰ Furthermore, some stakeholders have noted that the MMPA does not include provisions to handle recovered populations—unlike the ESA, which allows for delisting of species once they have recovered—and have called for agencies to implement more flexible regulations for thriving populations of marine mammals.²¹¹ Although increases in the number of incidental takes may be allowed with growing marine mammal populations, some experts state that negative and potentially unsafe interactions with marine mammals are also likely to increase.²¹²

If Congress chooses to address the trade-offs of marine mammal conservation with fisheries, including potential economic effects to fishers from fishing restrictions, one option would be to consider amending the MMPA. The MMPA includes provisions specifying that take reduction plans are to account for the economics of a given fishery and the availability of existing technology.²¹³ Additionally, interim provisions in the MMPA regarding exemptions for commercial fisheries mandated that the Secretary account for these factors when prescribing emergency regulations.²¹⁴ Congress could specify these considerations further. For example, to assist fishers in modifying their gears to minimize entanglement risk to North Atlantic right whales, H.R. 7042 and S. 3765, introduced in the 117^th Congress, would have established grants for states to assist lobster and Jonah crab harvesters with the costs of gear modification in accordance with the ALWTRP. The Consolidated Appropriations Act, 2023, included a grant authority for the Secretary of Commerce to establish a program to provide annual competitive financial assistance and multiyear grants and direct payments to vessel operators and participants in the fishing industry.²¹⁵ Eligible uses of these funds include "subsidizing acquisition of innovative gear technologies to improve adoption of those technologies by fisheries participants."²¹⁶ Congress also may consider amending the MMPA in support of continued fishing restrictions or limiting specific fishing practices to particular situations. Congress may additionally opt to retain current approaches and leave discretion to agencies regarding these considerations.

An additional option would be for Congress to consider directing agencies to examine interactions between marine mammals and commercial fisheries to account for the effects of marine mammal conservation actions on the fishing industry. Congress has used this approach recently for certain topics. For example, Congress has directed NOAA in explanatory statements accompanying appropriations acts to evaluate the feasibility, safety, and economic implications of management actions relating to North Atlantic right whales.²¹⁷ Congress also directed NMFS to study interactions between the U.S. fishing fleet and false killer whales in the western Pacific and to assess fishing interference by dolphins on Gulf of Mexico and South Atlantic fisheries.²¹⁸ Furthermore, Congress could consider directing additional research into technological innovations for mitigating fisher-marine mammal interactions. For example, in P.L. 116-188, Congress established the Theodore Roosevelt Genius Prize for Reducing Human Predator Conflict, which is a competition to encourage technological innovations that reduce the frequency of human-predator conflict using nonlethal means that may include tagging technologies.²¹⁹ Congress could consider similar provisions in the MMPA for the development of technologies toward minimizing human-marine mammal conflicts for commercial fisheries. Another option for Congress would be to conduct additional oversight of NOAA and FWS research into these topics. For example, in the explanatory statement of the Consolidated Appropriations Act, 2021 (P.L. 116-260), Congress directed NOAA to brief the committees on the prospect of expanding research monitoring the mortality of spring Chinook salmon in the Columbia River to understand the impacts of marine mammal predation.²²⁰ Such studies, research, and oversight activities may inform Congress's decision on whether to consider amending the MMPA.