The Marine Mammal Protection Act (P.L. 92522): Primer and Issues for Congress

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The Marine Mammal Protection Act

(P.L. 92-522): Primer and Issues for Congress

Updated June 25, 2026

Congressional Research Service

https://crsreports.congress.gov

R47892

SUMMARY

The Marine Mammal Protection Act

(P.L. 92-522): Primer and Issues for Congress

R47892

June 25, 2026

Anthony R. Marshak

Analyst in Natural

Congress passed the Marine Mammal Protection Act (MMPA) in 1972 (P.L. 92-522; 16 U.S.C.

Resources Policy

§§1361-1423h) to conserve marine mammal populations and protect them from extinction or

depletion as a result of human activities. Since enactment, Congress has amended the MMPA at

times and passed the most recent comprehensive amendments in 1994 (P.L. 103-238). The

MMPA intersects with other marine-related legislation, such as the Endangered Species Act (16

U.S.C. §§1531-1544) and the Magnuson-Stevens Fishery Conservation and Management Act (16

U.S.C. §§1801-1891d). The MMPA, as amended, contains five main provisions, each of which is codified as a separate title

and subchapter. Titles I, II, and IV focus on marine mammal protection broadly, whereas Titles III and V focus on specific

marine mammal species. Only Titles I, II, and IV are summarized below.

Title I of the MMPA, “Conservation and Protection of Marine Mammals,” includes the majority of the act’s provisions,

which focus on conserving and protecting marine mammals to ensure they remain “a significant functioning element in the

ecosystem” and at “optimum sustainable populations” (i.e., population size resulting in maximum productivity). The National

Oceanic and Atmospheric Administration (NOAA) and the U.S. Fish and Wildlife Service (FWS) primarily administer these

provisions, together with the Marine Mammal Commission (MMC; discussed below). Title I includes provisions for

•

the moratorium on taking and importing marine mammals and marine mammal products, including

exemptions and issuance of permits by federal agencies for limited takes (i.e., harassing, hunting,

capturing, killing, or attempting those activities) of marine mammals;

•

federal agencies to determine the status of marine mammal stocks through regular population assessments

and to develop plans to conserve depleted stocks (i.e., stocks below their optimum sustainable populations)

or strategic stocks (i.e., populations where human-caused mortality exceeds the maximum amount that may

be removed while maintaining their optimum sustainable populations);

•

federal agency regulations and administration of the MMPA;

commercial fishing implications of the MMPA; and

domestic and international government engagements, research grants, and regional programs and

provisions.

Title II of the MMPA established the MMC, whose mission is “to provide independent, science-based oversight of domestic

and international policies and actions of federal agencies addressing human impacts on marine mammals and their

ecosystems.” Title II also includes provisions for the MMC’s composition and functioning, including committees and

consultations with federal agencies.

Title IV of the MMPA established the Marine Mammal Health and Stranding Response Program. This program collects and

disseminates information on the health of marine mammals, coordinates responses to marine mammal strandings, and

establishes a process for handling unusual mortality events (i.e., unexpected strandings that include a significant die-off of

any marine mammal populations and demand an immediate response).

Congress has long shown interest in the MMPA, marine mammal conservation in general, and conservation’s associated

trade-offs with ocean sectors. Some Members and committees have discussed the emerging threats from environmental and

human-associated stressors, including climate change, on marine mammal populations and their habitats; impacts to

subsistence communities that depend on these species; and data gaps in understanding the ecology and population dynamics

of marine mammals, including effects from emerging domestic and international offshore activities. Congress also has

contemplated marine mammal management in the context of ecosystem-based management approaches that consider multiple

ocean use sectors, and with respect to the effects of marine mammal conservation on fisheries species and fishing practices.

These issues also have been raised by some stakeholders in recent years, including with respect to evolving conservation and

management practices in consideration of these environmental and socioeconomic factors. Congress may consider whether or

not to enact refinements or comprehensive amendments to the MMPA. Congress also may pursue oversight of certain agency

activities, including directing studies or programs that may inform potential amendments to the MMPA.

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The Marine Mammal Protection Act: Primer and Issues for Congress

Contents

Introduction ..................................................................................................................................... 1

Purpose of the Marine Mammal Protection Act .............................................................................. 3

Implementation of the Marine Mammal Protection Act ................................................................. 4

Title I: Conservation and Protection of Marine Mammals .............................................................. 6

Moratorium on Taking and Importing Marine Mammals and Marine Mammal

Products.................................................................................................................................. 6

Authorizations, Permits, and Specific Exemptions ............................................................. 7

Marine Mammal Status Determinations, Stock Assessments, and Conservation Plans .......... 12

Status Determinations ....................................................................................................... 12

Stock Assessments ............................................................................................................ 12

Conservation Plans and Requirements .............................................................................. 15

Administration, Regulations, and Program Reviews .............................................................. 16

Commercial Fishing and the MMPA....................................................................................... 16

Taking of Marine Mammals Incidental to Commercial Fishing Operations .................... 17

Take Reduction Plans ........................................................................................................ 18

Commercial Fisheries Gear Development and Marine Mammal Research Grants .......... 19

Federal-State Engagements, International Agreements, and Regional Provisions.................. 21

Federal Cooperation with States ....................................................................................... 21

International Agreements .................................................................................................. 21

Regional Provisions .......................................................................................................... 22

Title IV: Marine Mammal Health and Stranding Response .......................................................... 23

Unusual Mortality Events ....................................................................................................... 25

Issues and Options for Congress ................................................................................................... 26

Climate Change and the Marine Mammal Protection Act ...................................................... 26

Ecosystem-Based Management and the MMPA ..................................................................... 29

Trade-Offs Between Marine Mammal Conservation and U.S. Fisheries ................................ 32

Figures

Figure 1. Percentage of Strategic Marine Mammal Stocks in U.S. Regions over Time................ 15

Tables

Table 1. Authorizations and Permits for Incidental and

Directed Takes of Marine Mammals ............................................................................................ 8

Contacts

Author Information........................................................................................................................ 35

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The Marine Mammal Protection Act: Primer and Issues for Congress

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. Example increases in observed populations include the

western North Atlantic bottlenose dolphin, west Arctic bowhead whale, and a number of seal, sea

lion, 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

1 National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service (NMFS), “Marine

Mammals,” https://www.noaa.gov/education/resource-collections/marine-life/marine-mammals (hereinafter, NOAA,

NMFS, “Marine Mammals”).

2 Ana D. Davidson et al., “Drivers and Hotspots of Extinction Risk in Marine Mammals,” Proceedings of the National

Academy of Sciences, vol. 109, no. 9 (2012), pp. 3395-3400. Hereinafter Davidson et al., “Drivers and Hotspots of

Extinction Risk in Marine Mammals.”

3 Davidson et al., “Drivers and Hotspots of Extinction Risk in Marine Mammals”; NOAA, NMFS, “Marine Mammals.”

4 Matthew D. Lettrich et al., “Vulnerability to Climate Change of United States Marine Mammal Stocks in the Western

North Atlantic, Gulf of Mexico, and Caribbean,” PLoS One, vol. 18, no. 9 (2023), e0290643, pp. 1-37 (hereinafter,

Lettrich et al., “Vulnerability to Climate Change”).

5 Lettrich et al., “Vulnerability to Climate Change”; Frances M.D. Gulland et al., “A Review of Climate Change Effects

on Marine Mammals in United States Waters: Past Predictions, Observed Impacts, Current Research and Conservation

Imperatives,” Climate Change Ecology, vol. 3 (2022), 100054, pp. 1-17 (hereinafter, Gulland et al., “Climate Change

Effects on Marine Mammals).

6 A. M. Magera et al., “Recovery Trends in Marine Mammal Populations,” PLoS One, vol. 8, no. 10 (2013), e77908,

pp. 1-12; and Sean A. Hayes et al., U.S. Atlantic and Gulf of America Marine Mammal Stock Assessments 2024,

NOAA, NMFS, July 2025, pp. 1-222, https://www.fisheries.noaa.gov/s3/2026-04/atlantic_2024_mmsars.pdf..

7 NOAA, NMFS, “Marine Mammals”; Lettrich et al., “Vulnerability to Climate Change”; NOAA, NMFS, “Final 2024

Marine Mammal Stock Assessment Reports,” 91 Federal Register 21421-21425, April 22, 2026.

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The Marine Mammal Protection Act: Primer and Issues for Congress

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, Congress

continues to face issues relating to marine mammal protection and conservation, including in the

context of potential economic and management trade-offs with other ocean sectors.10

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.11 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).12 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 nonfishing 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. This title is not covered in detail

in this report.13

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.

8 McDowell Group, Economic Analysis of Whale Watching Tourism in Alaska, prepared for NOAA, October 2020, pp.

1-38, https://media.fisheries.noaa.gov/2020-11/Economic-Analysis-Whale-Watching-Tourism-Alaska.pdf?VersionId=

null; Simon O’Connor et al., Whale Watching Worldwide: Tourism Numbers, Expenditures and Expanding Economic

Benefits, International Fund for Animal Welfare, a special report from the International Fund for Animal Welfare,

prepared by Economists at Large, Yarmouth, MA, 2009, pp. 1-295, https://www.mmc.gov/wp-content/uploads/

whale_watching_worldwide.pdf.

9 Joe Roman and James J. McCarthy, “The Whale Pump: Marine Mammals Enhance Primary Productivity in a Coastal

Basin,” PLoS One, vol. 5, no. 10 (2010), e13255, pp. 1-8. Heidi C. Peterson et al., “Whales in the Carbon Cycle: Can

Recovery Remove Carbon Dioxide?,” Trends in Ecology and Evolution, vol. 38, no. 3 (2023), pp. 238-249.

10 See, as examples, CRS In Focus IF12776, The North Atlantic Right Whale: Conservation Trade-Offs with Selected

Marine Sectors and Considerations for Congress, by Anthony R. Marshak and Pervaze A. Sheikh; and CRS In Focus

IF12835, The Rice’s Whale: Conservation Efforts, Implications for Ocean Sectors, and Considerations for Congress,

by Anthony R. Marshak and Laura B. Comay.

The Marine Mammal Protection Act (MMPA; P.L. 92-522; 16 U.S.C. §§1361-1423h), under 16 U.S.C. §1362(1),

defines depletion or depleted as

any case in which—(A) the Secretary [of Commerce or of the Interior], after consultation with the

Marine Mammal Commission and the Committee of Scientific Advisors on Marine Mammals

established under [16 U.S.C. §§1401-1407], determines that a species or population stock is below

its optimum sustainable population; (B) a State, to which authority for the conservation and

management of a species or population stock is transferred under [16 U.S.C. §1379], determines

that such species or stock is below its optimum sustainable population; or (C) a species or

population stock is listed as an endangered species or a threatened species under the Endangered

Species Act of 1973 [16 U.S.C. §1531 et seq.].

12 16 U.S.C. §§1361(2).

13 For additional information about the Marine Mammal Commission, see CRS In Focus IF13015, The Marine

Mammal Commission, by Anthony R. Marshak.

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The Marine Mammal Protection Act: Primer and Issues for Congress

•

Title IV: Marine Mammal Health and Stranding Response. This title includes

provisions with respect to coordinating a marine mammal stranding network,14

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.15 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 specific 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.16 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.”17 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),18 or beyond the point where they cease to be a significant

functioning element in their particular ecosystem.19 The act’s primary objectives for marine

14 See footnote 161 for a definition of stranding.

15 United Nations, Agreement on the Conservation of Polar Bears (with Final Act and Resolution), vol. 2898, no.

50540, November 15, 1973, pp. 245-257, https://treaties.un.org/doc/Publication/UNTS/Volume%202898/Part/volume2898-I-50540.pdf.

16 16 U.S.C. §1361(2); NOAA, NMFS, “Marine Mammal Protection Act Policies, Guidance, and Regulations,”

https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-protection-act-policies-guidanceand-regulations; Erica Fleishman et al., “Monitoring Population-Level Responses of Marine Mammals to Human

Activities,” Marine Mammal Science, vol. 32, no. 3 (2016), pp. 1004-1021.

17 16 U.S.C. §1362(6).

18 16 U.S.C. §1361(1)-(2); The MMPA, under 16 U.S.C. §1362(9), defines optimum sustainable population (OSP) as

“with respect to any population stock, the number of animals which will result in the maximum productivity of the

population or the species, keeping in mind the carrying capacity of the habitat and the health of the ecosystem of which

they form a constituent element.”

19 16 U.S.C. §1361(2).

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The Marine Mammal Protection Act: Primer and Issues for Congress

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.20 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.21

Experts and stakeholders have referred to the recovery of multiple seal populations off New

England and California—and comparative increases in humpback, blue, and gray whales in recent

decades—as evidence of the act’s value.22 Furthermore, the act emphasizes the importance of and

need for marine mammal research and conservation.23

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).24

FWS is responsible for the protection of walruses, sirenians, sea otters, and polar

bears.25

20 16 U.S.C. §1361(6); Marine Mammal Commission (MMC), “Marine Mammal Protection Act,”

https://www.mmc.gov/about-the-commission/our-mission/marine-mammal-protection-act/. The MMPA does not define

carrying capacity. NOAA defines carrying capacity as

1. The maximum population of a species that an area or specific ecosystem can support

indefinitely without deterioration of the character and quality of the resource; 2. The level of use, at

a given level of management, at which a natural or man-made resource can sustain itself over a

long period of time. For example, the maximum level of recreational use, in terms of numbers of

people and types of activity that can be accommodated before the ecological value of the area

declines.

NOAA, NOAA Fisheries Glossary, NOAA Technical Memorandum NMFS-F/SPO-69, 2006, p. 5,

https://repository.library.noaa.gov/view/noaa/12856.

21 The MMPA extends essential habitats to marine mammal rookeries and mating grounds. 16 U.S.C. §1361(2).

22 Joe Roman et al., “The Marine Mammal Protection Act at 40: Status, Recovery, and Future of U.S. Marine

Mammals,” Annals of the New York Academy of Sciences, vol. 1286, no. 2013 (2013), pp. 29-49 (hereinafter, Roman et

al., “Marine Mammal Protection Act at 40”). See also NOAA, NMFS, “2019-2023 Eastern North Pacific Gray Whale

[Unusual Mortality Event] (Closed),” https://www.fisheries.noaa.gov/national/marine-life-distress/2019-2023-easternnorth-pacific-gray-whale-ume-closed (hereinafter NOAA, NMFS, “2019-2023 Eastern North Pacific Gray Whale UME

(Closed)”). For more information about Unusual Mortality Events, see “Unusual Mortality Events.”

23 16 U.S.C. §§1361(3)-(4).

24 Cetaceans (i.e., Order Cetacea) include dolphins, porpoises, and whales. Pinnipeds (i.e., Order Pinnipedia) include

seals, sea lions, and walruses. 16 U.S.C. §1362(12). In accordance with provisions for the Secretary of Commerce;

NOAA, NMFS, “Marine Mammal Protection: Conservation [and] Management,” https://www.fisheries.noaa.gov/topic/

marine-mammal-protection/conservation-&-management (hereinafter, NOAA, NMFS, “Marine Mammal Protection:

Conservation & Management”).

25 Sirenians (i.e., Order Sirenia) include manatees and dugongs. 16 U.S.C. §1362(12). In accordance with provisions for

the Secretary of the Interior; U.S. Fish and Wildlife Service (FWS), “Marine Mammals,” https://www.fws.gov/

program/marine-mammals; NOAA, NMFS, “Marine Mammal Protection: Conservation & Management.”

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The Marine Mammal Protection Act: Primer and Issues for Congress

•

The MMC, established in Title II of the MMPA,26 provides independent, sciencebased administration of domestic and international policies and federal agency

actions addressing human impacts on marine mammals and their ecosystems.27

Additionally, NMFS and FWS have developed regulations to implement the MMPA, including

for managing fishing and nonfishing impacts on marine mammals and regarding the import,

export, and transportation of marine mammals.28 MMC regulations also govern agency practices,

compliance with other legislation, and public availability of agency materials.29

The Marine Mammal Commission

The mission of the Marine Mammal Commission (MMC) is “to provide independent, science-based oversight of

domestic and international policies and actions of federal agencies addressing human impacts on marine mammals

and their ecosystems.”

The MMC is an independent advisory agency composed of three members (commissioners), who are

knowledgeable in marine ecology and resource management. Commissioners serve three-year terms and are not

eligible for reappointment. The commissioners are appointed by the President and confirmed by the Senate. The

President also designates a chair of the MMC from among the commissioners; the chair may appoint and assign

duties to an executive director and administrative staff, with the MMC’s approval.

MMC duties include the following:

•

Reviewing and studying U.S. activities pursuant to existing laws and international conventions relating to

marine mammals

•

Reviewing (1) the condition of marine mammal stocks, (2) methods for their protection and conservation, (3)

humane means for taking marine mammals, (4) proposed or in-place research programs under the Marine

Mammal Protection Act (MMPA; P.L. 92-522; 16 U.S.C. §§1361-1423h), and (5) all applications for scientific

research permits and those for public display or for enhancing the survival of a species or stock

•

Conducting and/or facilitating studies relating to the protection and conservation of marine mammals

•

Recommending federal actions for the protection and conservation of marine mammals

•

Recommending federal measures to further policies of the MMPA, including activities that protect Indians and

Alaskan Natives whose livelihood may be adversely affected by actions taken pursuant to the MMPA

•

Recommending policies to the Secretary of State for protecting and conserving marine mammals covered

under international agreements or arrangements

The MMC also includes a Committee of Scientific Advisors on Marine Mammals (the committee), which consists

of nine scientists appointed by the MMC chair after consultation with the chairs of the Council on Environmental

Quality and the National Academy of Sciences and the directorate of the Smithsonian Institution and the National

Science Foundation. The MMC is to consult with the committee on all studies, recommendations, and research

programs that it proposes or undertakes and in reviewing all applications for scientific research permits. The MMC

also is to have access to all studies and data compiled by federal agencies regarding marine mammals. If the MMC

does not adopt a recommendation made by the committee or any of its members, the MMPA requires the MMC

to transmit a detailed explanation of its reasons for not accepting such recommendations to Congress and the

appropriate federal agency. Furthermore, although the MMC is not a regulatory agency, its comments are to be

taken into consideration by relevant action agencies. Should an agency choose to not follow the MMC’s

recommendations, it must provide a rationale for taking a different approach.

The MMC is to provide an annual report to Congress in consultation with the Secretary of Commerce and/or the

Secretary of the Interior. All reports and recommendations made by the MMC are required to be publicly

available.

26 16 U.S.C. §§1401-1407.

27 The MMC regularly consults with NMFS, FWS, and other federal agencies; MMC, “Our Mission,”

https://www.mmc.gov/about-the-commission/our-mission/ (hereinafter, MMC, “Our Mission”); NOAA, NMFS,

“Marine Mammal Protection: Conservation & Management.”

28 NMFS regulations are found at 50 C.F.R. §§216.1-219.40, 228.1-229.37. USFWS regulations are found at 50 C.F.R.

§§14.18, 18.1-18.152.

29 50 C.F.R. §§501.1-560.8.

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Sources: 16 U.S.C. §§1401-1407; Marine Mammal Commission (MMC), “Marine Mammal Commission: An

Independent Agency of the U.S. Government,” https://www.mmc.gov/; MMC, “About the Commission,”

https://www.mmc.gov/about-the-commission/. For additional information about the MMC, see CRS In Focus

IF13015, The Marine Mammal Commission, by Anthony R. Marshak.

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.30 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,31 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.32 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.33 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”).34 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”).35

30 Title I of the MMPA, 16 U.S.C. §§1371-1393, is also codified as Subchapter II of 16 U.S.C. §§1362-1423h (i.e.,

Chapter 31—Marine Mammal Protection).

31 Under §§110 and 119-120 of the MMPA. 16 U.S.C. §§1380(c)-(d), 1388-1389.

32 Under §§101 and 104 of the MMPA. 16 U.S.C. §§1371(a)-(f), 1374.

33 16 U.S.C. §1372(a)(1)-(5).

34 16 U.S.C. §1371(a)(4).

35 16 U.S.C. §1371(a)(5).

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The Marine Mammal Protection Act: Primer and Issues for Congress

The MMPA directs the Secretary of Commerce or the Secretary of the Interior (i.e., the

Secretary)36 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.37 Regulations are to be periodically

reviewed and may be modified at the Secretary’s discretion.38 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.39

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.40

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)41 of

marine mammals during commercial fishing operations (see “Taking of Marine Mammals

Incidental to Commercial Fishing Operations”),42 as well as during nonfishing activities (e.g.,

offshore energy exploration).43 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.44

36 In this report, the Secretary refers to the Secretary of Commerce and/or the Secretary of the Interior as appropriate to

jurisdiction, unless otherwise specified.

37 Under §103, 16 U.S.C. §1373(a).

38 16 U.S.C. §1373(e).

39 16 U.S.C. §1373(b).

40 16 U.S.C. §§1371-1374; NOAA, NMFS, “Incidental Take Authorizations Under the Marine Mammal Protection

Act,” https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act

(hereinafter, NOAA, NMFS, “Incidental Take Authorizations Under the Marine Mammal Protection Act”); FWS,

“Incidental Take Authorizations for Marine Mammals,” https://www.fws.gov/service/incidental-take-authorizationsmarine-mammals (hereinafter, FWS, “Incidental Take Authorizations for Marine Mammals”).

41 50 C.F.R. §216.103.

42 As administered by the Secretary of Commerce. 16 U.S.C. §§1371(a)(2), 1373-1374, 1387, 1416.

43 These authorizations are administered by either the Secretary of Commerce or the Secretary of the Interior,

depending on jurisdiction. 16 U.S.C. §1371(a)(5). The MMPA does not define negligible impact. 50 C.F.R. §18.27(c)

defines negligible impact as “an impact resulting from the specified activity that cannot be reasonably expected to, and

is not reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or

survival.”

44 NOAA, NMFS, “Understanding Permits and Authorizations for Protected Species—What’s the Difference Between

Directed and Incidental Take?,” https://www.fisheries.noaa.gov/insight/understanding-permits-and-authorizationsprotected-species#what%E2%80%99s-the-difference-between-directed-and-incidental-take?-.

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Table 1. Authorizations and Permits for Incidental and

Directed Takes of Marine Mammals

Type of Authorization

Authorized Activities

Federal Agency

Citations

Marine Mammal

Authorization

Incidental take of marine

mammals during U.S.

commercial fishing

operations

NMFS

16 U.S.C. §§1371, 1387(c),

1416;

50 C.F.R. §§229.1-229.37

Incidental Take

Authorization (ITA)

Incidental take of marine

mammals during

nonfishing activities,

including those by the

military, energy, scientific,

and marine construction

sectors

FWS or NMFS

16 U.S.C. §1371(a)(5)(A)-(D);

50 C.F.R. §§18.1-18.152;

50 C.F.R. §§216.1-219.40

Incidental Harassment

Authorization

An ITA for small-scale

nonfishing activities or

those expected to result

only in marine mammal

harassment

FWS or NMFS

See citations for an ITA.

Letter of Authorization

(LOA)

Incidental Take Regulation

(ITR)

An ITA for larger-scale

activities or those that

may cause serious injury

or mortality to marine

mammals

NMFS or FWS

each issue LOAs

FWS issues ITRs

MMC consults on

specifically issued

regulations for a

given activity

16 U.S.C. §1373(a);

see also citations for an ITA.

Specific permits may be

issued for scientific, public

display, enhancement,

relocation, and/or

photography purposes or

for importing polar bear

parts

NMFS, FWS, and

in consultation

with the MMC

16 U.S.C. §§1371, 1374;

50 C.F.R. §§18.1-18.34;

50 C.F.R. §§216.1-216.50

Incidental Takes

Directed Takes

Permits

Sources: 16 U.S.C. §§1371, 1374, 1387, 1416; 50 C.F.R. §§18.1-18.152; 216.1-219.40; National Oceanic and

Atmospheric Administration (NOAA), National Marine Fisheries Service (NMFS), “Understanding Permits and

Authorizations for Protected Species,” https://www.fisheries.noaa.gov/insight/understanding-permits-andauthorizations-protected-species; NOAA, NMFS, “Incidental Take Authorizations Under the Marine Mammal

Protection Act,” https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammalprotection-act; NOAA, NMFS, “Marine Mammal Authorization Program,” https://www.fisheries.noaa.gov/

national/marine-mammal-protection/marine-mammal-authorization-program; U.S. Fish and Wildlife Service

(FWS), “Incidental Take Authorizations for Marine Mammals,” https://www.fws.gov/service/incidental-takeauthorizations-marine-mammals; FWS, “3-200-43: Take/Import/Transport/Export of Marine Mammals or

Amendment of Permit (MMPA; ESA),” https://www.fws.gov/service/3-200-43-takeimporttransportexport-marinemammals-or-amendment-permit-mmpa-esa.

Notes: MMC = Marine Mammal Commission. Incidental Harassment Authorizations, Letters of Authorization,

and Incidental Take Regulations are all types of Incidental Take Authorizations. The Marine Mammal Protection

Act (P.L. 92-522; 16 U.S.C. §§1361-1423h) defines take as “to harass, hunt, capture, or kill, or attempt to harass,

hunt, capture, or kill any marine mammal.” NMFS defines a directed take as an activity that is a purposeful

interaction with the protected animal for a specific purpose that may result in a take. NMFS defines incidental

take as “an accidental taking. This does not mean that the taking is unexpected, but rather it includes those

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The Marine Mammal Protection Act: Primer and Issues for Congress

takings that are infrequent, unavoidable or accidental.” FWS defines incidental, but not intentional, taking as “takings

which are infrequent, unavoidable, or accidental. It does not mean that the taking must be unexpected.”

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 nonfishing oceanic activities.45 Additionally, the MMPA allows the Secretary to

issue permits allowing for marine mammals to be taken incidentally during military readiness

activities.46 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 smallscale 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.”47

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,48 and Level B harassment, which has the potential to

disturb marine mammals and disrupt their behavioral patterns.49

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.50 NOAA and FWS also publish specific regulations related

to these authorized takes, in consultation with the MMC.51

Incidental Take Authorizations are issued to applicants following review by

45 16 U.S.C. §1371(a)(5); 50 C.F.R. §216; the incidental taking of California sea otters, including with respect to their

translocation, is not included under these provisions, as established in P.L. 99-625 and 16 U.S.C. §§1371(a)(5)(E)(vi).

P.L. 99-625 is otherwise known as “An Act to improve the operation of certain fish and wildlife programs.”

46 16 U.S.C. §§1371(a)(5)(A)(ii)-(iv), 1371(a)(5)(D)(vi)-(vii), 1371(a)(5)(F); 16 U.S.C. §703 note.

47 16 U.S.C. §1362(18).

48 16 U.S.C. §1362(18)(A)(i), (B)(i), (C). For additional information on temporary and permanent threshold shifts, see

NOAA, NMFS, 2024 Update to: Technical Guidance for Assessing the Effects of Anthropogenic Sound on Marine

Mammal Hearing (Version 3.0): Underwater and In-Air Criteria for Onset of Auditory Indury and Temporary

Threshold Shifts, NOAA Technical Memorandum NMFS-OPR-71, October 2024, pp. 7-8,

https://repository.library.noaa.gov/view/noaa/66184.

49 16 U.S.C. §1362(18)(A)(ii), (B)(ii), (D).

50 NOAA issues a Letter of Authorization (LOA) for larger-scale activities for periods up to five years for nonmilitary

readiness activities and seven years for military readiness activities. Under a different process, FWS issues an

Incidental Take Regulation (ITR) as an initial step for authorizing larger-scale activities. Once FWS promulgates an

ITR, U.S. citizens covered in the ITR may then request an LOA to carry out activities that fall under the ITR analysis.

NOAA, NMFS, “Incidental Take Authorizations Under the Marine Mammal Protection Act”; FWS, “Incidental Take

Authorizations for Marine Mammals.”

51 NOAA, NMFS, “Incidental Take Authorizations Under the Marine Mammal Protection Act”; FWS, “Incidental Take

Authorizations for Marine Mammals.”

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NOAA or FWS and notice and opportunity for public comment in the Federal

applicants to define appropriate monitoring and mitigation measures for

minimizing adverse effects on marine mammals.53

Endangered Species Act Intersections

The Marine Mammal Protection Act (MMPA; P.L. 92-522; 16 U.S.C. §§1361-1423h) intersects with the Endangered

Species Act (ESA; 16 U.S.C. §§1531-1544), as related to ESA-listed threatened and endangered marine mammals

and with respect to required consultations for specific activities. Section 7 of the ESA (16 U.S.C. §1536(b)(4))

includes specific reference to marine mammals and the MMPA.

Section 7(a) of the ESA requires interagency consultation on any proposed actions or activities that may affect

ESA-listed species or their designated critical habitat. The authorized taking of marine mammals under the MMPA,

as covered under agency-issued incidental take authorizations, is a federal action that requires an ESA Section 7

consultation.

Section 7(b) of the ESA states that if an endangered or threatened marine mammal species is involved in the

activity requiring consultation, the taking of that marine mammal is to be authorized under the MMPA prior to any

written statement from the Secretary on the impact of incidental taking on the ESA-listed species. That written

statement also is to specify “reasonable and prudent measures that the Secretary considers necessary or

appropriate to minimize such impact” and, in the case of marine mammals, specifies those measures that are

necessary to comply with the MMPA regarding such taking. Therefore, the National Oceanic and Atmospheric

Administration (NOAA) or U.S. Fish and Wildlife Service (FWS) cannot issue an incidental take statement for

marine mammals under the ESA until an MMPA incidental take authorization has been issued.

There are other intersections between the MMPA and the ESA. For example, provisions codified along with the

ESA regarding the translocation of California sea otters stipulate that any incidental taking during an otherwise

lawful activity in the management zone, or necessary sea otter relocation or management action, may not be

treated as violating the MMPA (16 U.S.C. §1536 note). Additionally, Section 17 of the ESA (16 U.S.C. §1543) states

that no provision of the ESA “shall take precedence over any more restrictive conflicting provision” of the MMPA.

Sources: 16 U.S.C. §§1536(a)-(b), 1536 note, 1539(j), 1543; NOAA, National Marine Fisheries Service (NMFS),

“ESA Section 7 Consultation Tools for Marine Mammals on the West Coast,” https://www.fisheries.noaa.gov/

west-coast/endangered-species-conservation/esa-section-7-consultation-tools-marine-mammals-west; NOAA,

NMFS, “Incidental Take Authorizations Under the Marine Mammal Protection Act,”

https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act; FWS,

“Incidental Take Authorizations for Marine Mammals,” https://www.fws.gov/service/incidental-take-authorizationsmarine-mammals.

Notes: The ESA, under 16 U.S.C. §1532(5)(A), defines critical habitat for a threatened or endangered species as

the specific areas within the geographical area occupied by the species, at the time it is listed in accordance

with the provisions of section 1533 of this title, on which are found those physical or biological features (I)

essential to the conservation of the species and (II) which may require special management considerations

or protection; and (ii) specific areas outside the geographical area occupied by the species at the time it is

listed in accordance with the provisions of section 1533 of this title, upon a determination by the Secretary

that such areas are essential for the conservation of the species.

16 U.S.C. §1536 note defines translocation as occurring from the existing range of the parent population to another

location (i.e., known as the management zone, which surrounds the translocation zone to which an experimental sea

otter population is relocated and does not include the existing range of the parent population or adjacent range

where expansion is necessary for the recovery of the species).

16 U.S.C. §1539(j) defines an experimental population as “any population (including any offspring arising solely

therefrom) authorized by the Secretary for release under paragraph (2), but only when, and at such times as, the

population is wholly separate geographically from nonexperimental populations of the same species.”

52 16 U.S.C. §1371(a)(5); NOAA, NMFS, “Apply for an Incidental Take Authorization,”

https://www.fisheries.noaa.gov/national/marine-mammal-protection/apply-incidental-take-authorization; FWS,

“Incidental Take Authorizations for Marine Mammals.”

53 NOAA, NMFS, “Apply for an Incidental Take Authorization,” https://www.fisheries.noaa.gov/national/marinemammal-protection/apply-incidental-take-authorization; FWS, “Incidental Take Authorizations for Marine Mammals.”

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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.54

Photography for educational or commercial purposes.55

Importing polar bear parts taken in sport hunts in Canada.56

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 [under

“Implementation of the Marine Mammal Protection Act”] for more information about the

committee).57 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.58 The Secretary also may

modify, suspend, or revoke any issued permit.59

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,60 for ensuring the health and

survival of a marine mammal (i.e., “Good Samaritan exemption),61 and for takes associated with

Alaska Native subsistence activities or for creating and selling authentic Native articles of

handicrafts and clothing.62

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.63 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.64 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.65

54 16 U.S.C. §§1371(a)(1), 1374(c)(1)-(2).

16 U.S.C. §§1371(a)(1), 1374(c)(1), (6).

56 16 U.S.C. §§1371(a)(1), 1374(c)(1), 1374(c)(5), 1374(e).

57 16 U.S.C. §§1371(a)(1), 1374(c).

58 16 U.S.C. §1371(d).

59 16 U.S.C. §1371(e).

60 16 U.S.C. §§1371(c), (f).

61 16 U.S.C. §1371(d).

62 16 U.S.C. §1371(b).

63 16 U.S.C. §1375.

64 16 U.S.C. §1376.

65 16 U.S.C. §1377.

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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.66 This information allows federal agencies to evaluate the

effectiveness of conservation and protection measures and to adjust management approaches as

necessary.67

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.68 The Secretary

may independently initiate a determination or may do so in response to a petition for a status

review.69 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.70 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.71 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.72 As of June 2026, 56 domestic and foreign marine mammal stocks were listed as

depleted.73

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.74 The assessment for each marine mammal contains

scientific information on its geographic range, trends in abundance, population structure, human-

66 NOAA, NMFS, “Marine Mammal Stock Assessments,” https://www.fisheries.noaa.gov/national/marine-mammal-

protection/marine-mammal-stock-assessments. Hereinafter NOAA, NMFS, “Marine Mammal Stock Assessments.”

67 NOAA, NMFS, “Marine Mammal Stock Assessments.”

16 U.S.C. §1383b(a).

69 16 U.S.C. §1383b(a)(2)-(3).

70 16 U.S.C. §1383b(a)(2).

71 S. Bettridge, “Guidelines for Preparing Stock Assessment Reports Pursuant to the Marine Mammal Protection Act,”

NOAA, NMFS, Protected Resources Policy Directive Marine Mammal Protection Act 02-204, February 7, 2023, p. 16,

https://www.fisheries.noaa.gov/s3/2023-05/02-204-01-Final-GAMMS-IV-Revisions-clean-1-kdr.pdf.

72 16 U.S.C. §1362(1)(C).

73 These species include 35 distinct populations of dolphins, porpoises, and whales; 13 distinct populations of

pinnipeds; 4 species of sirenians; 3 species of sea otters; and the polar bear. MMC, “Status of Marine Mammal Species

and Populations,” https://www.mmc.gov/priority-topics/species-of-concern/status-of-marine-mammal-species-andpopulations/.

74 As included in Section 117 of the MMPA. 16 U.S.C. §1386.

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caused mortality and serious injury, interactions with commercial fisheries,75 and additional

threats.76 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.77 Regional Scientific Review Groups (SRGs) advise the Secretary on these

assessments.78

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).79 The term strategic stock

also includes those stocks that are designated as depleted under the MMPA.80

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.81 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.82

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.83

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.84 The Secretary is to make available all draft stock assessments, or any revisions

thereof, for public comment over a 90-day period.85 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.86 Section 117 gives authority to the

75 16 U.S.C. §1386(a)(4) states that descriptions of commercial fisheries that interact with the stock are to include

(A) the approximate number of vessels actively participating in each such fishery; (B) the estimated

level of incidental mortality and serious injury of the stock by each such fishery on an annual basis;

based on the appropriate standard unit of fishing effort, of such incidental mortality and serious

injury, and an analysis stating whether such level is insignificant and is approaching a zero

mortality and serious injury rate.

76 16 U.S.C. §1386(a).

77 16 U.S.C. §1386(a)(5).

78 16 U.S.C. §1386(d). Regional Scientific Review Groups (SRGs) include individuals with expertise in marine

mammal biology, ecology, population dynamics and modeling, and commercial fishing, among other factors. The

SRGs advise the Secretary on marine mammal population status and trends, uncertainties and research needs, habitat

and environmental impacts to marine mammals, and appropriate marine mammal conservation and management

measures for alleviating impacts.

79 16 U.S.C. §1362(19). The MMPA also states that the potential biological removal level is a mathematical product of

“(A) The minimum population estimate of the stock; (B) one-half the maximum theoretical or estimated net

productivity rate of the stock at a small population size; and (C) a recovery factor of between 0.1 and 1.0.”

80 16 U.S.C. §1362(19).

81 16 U.S.C. §1362(20).

82 16 U.S.C. §1386(a)(6).

83 16 U.S.C. §1386(c).

84 16 U.S.C. §§1386(b), 1386(c)(2), 1386(d); see footnote 78.

85 16 U.S.C. §1386(b).

86 16 U.S.C. §§1386(a)-(d).

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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 America) regions.87

NOAA and FWS have conducted marine mammal stock assessments since 1995.88 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.89 Over time, the highest percentage of strategic

stocks have consistently occurred in the Atlantic region (including Gulf of America 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.90 However, consistency of strategic

stock percentages in more recent decades also may suggest consistency in MMPA effectiveness

among regions, as noted in one study.91

87 16 U.S.C. §1386(d).

88 16 U.S.C. §1386(a); NOAA, NMFS, “Marine Mammal Stock Assessment Reports by Region,”

https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region;

FWS, “Marine Mammal Stock Assessment Reports,” https://www.fws.gov/project/marine-mammal-stock-assessmentreports.

89 Roman et al., “Marine Mammal Protection Act at 40.”

90 Gulland et al., “Climate Change Effects on Marine Mammals.”

91 Gulland et al., “Climate Change Effects on Marine Mammals.”

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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/marinemammal-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-assessmentreports.

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. 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, Gulf of America, 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. §§15311544]). 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.92 The MMC also may provide

recommendations for conservation plans.93 The purpose of each plan is to conserve and restore

the species or stock to its OSP.94

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.95 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

92 16 U.S.C. §1383b(b). In addition to these requirements, the statute mandates that the Secretary also prepare

conservation plans specifically for North Pacific fur seals and Stellar sea lions.

93 16 U.S.C. §1402(a)(4), (6).

94 16 U.S.C. §1383b(b)(2).

95 16 U.S.C. §1383b(b)(4).

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included in the Secretary’s list of commercial fisheries (see “Commercial Fishing and the

MMPA” and “Take Reduction Plans” for more information).96

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.97

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.”98

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.99 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.100 The

Secretary also is to include any legislative recommendations for resolving the issues leading to

suspension of the program.101 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.”102

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;103 developing and devising commercial fisheries gear and commercial fishing practices to

minimize incidental takes;104 and granting take exemptions for commercial fisheries under certain

circumstances.105

96 16 U.S.C. §1362(24). See report sections “Taking of Marine Mammals Incidental to Commercial Fishing

Operations” and “Take Reduction Plans” for more information on the list of commercial fisheries and take reduction

plans.

97 As included under Section 112 of the MMPA, “Regulations and Administration.” 16 U.S.C. §1382.

98 50 C.F.R. §216.8.

16 U.S.C. §1382(d). The requirement for the annual report to Congress referenced in 16 U.S.C. §1382(d) was

eliminated under Section 3003 of the Federal Reports Elimination and Sunset Act of 1995 (P.L. 104-66, Title III).

According to FWS and NOAA, both agencies primarily carry out these reviews through their administration of

Incidental Take Authorizations. FWS Office of Congressional and Legislative Affairs and NOAA Office of Legislative

and Intergovernmental Affairs, email to CRS, January 31, 2024.

100 16 U.S.C. §1382(d).

101 16 U.S.C. §1382(d).

102 16 U.S.C. §1382(e). The Secretary may implement these measures following consultations with the MMC,

appropriate federal agencies, and opportunity for public comment.

103 16 U.S.C. §1387.

104 16 U.S.C. §1381.

105 16 U.S.C. §§1383a, 1387.

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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.106 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).107 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.108

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.109 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.110 In the 2024 annual list of

commercial fisheries (the most recently finalized as of June 8, 2026),111 examples of Category I

fisheries include Hawaiian deep-set longline fisheries,112 which are known to affect multiple

species of dolphins and whales, and Northeast/Mid-Atlantic American lobster and Jonah Crab

trap/pot fisheries, which affect three whale species.113 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.114 The Gulf of Maine

Atlantic herring purse seine fishery, which affects the harbor seal, is an example of a Category III

fishery.115

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

106 16 U.S.C. §1387(a)(5); 16 U.S.C. §1387(a)(4) stipulates that the incidental taking of California sea otters is not

included under these provisions, as also included in Section 101 (16 U.S.C. §§1371(a)(5)(E)(vi)).

107 16 U.S.C. §1387(a)-(b).

108 50 C.F.R. §229.1(g); FWS regulations also reference that goal at 50 C.F.R. §18.24.

109 16 U.S.C. §§1383a(b)(1)(A)-(C), 1387(c)(1)(A)-(C).

110 16 U.S.C. §§1383a(b)(1)(A)-(C), 1387(c)(1)(A)-(C); NOAA, NMFS, “Marine Mammal Protection Act List of

Fisheries,” https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-protection-act-listfisheries. Hereinafter NOAA, NMFS, “Marine Mammal Protection Act List of Fisheries.”

111 NOAA, NMFS, “Marine Mammal Protection Act List of Fisheries.”

112 NOAA, NMFS, “Fisheries Summary Tables,” https://www.fisheries.noaa.gov/national/marine-mammal-protection/

list-fisheries-summary-tables (hereinafter, NOAA, NMFS, “Fisheries Summary Tables”); a longline is a continuous

mainline set below the surface and supported in the water column horizontally by floats with branch lines attached at

intervals on the mainline. NOAA, NMFS, “Hawaii Deep-set Longline Fishery - MMPA List of Fisheries,”

https://www.fisheries.noaa.gov/national/marine-mammal-protection/hawaii-deep-set-longline-fishery.

113 NOAA, NMFS, “Fisheries Summary Tables.”

114 NOAA, NMFS, “Fisheries Summary Tables.”

115 NOAA, NMFS, “Fisheries Summary Tables”; a purse seine is a deep nylon mesh net with floats on the top and lead

weights on the bottom. Rings are fastened at intervals to the lead line, and a purse line runs completely around the net

through the rings. When fishing for Atlantic herring, one end of the net remains in the vessel and the other end is

attached to a power skiff or bug boat that is deployed from the stern of the vessel and remains in place while the vessel

encircles a school of fish with the net. Then the net is pursed and brought back aboard the vessel through a hydraulic

power block. NOAA, NMFS, “Gulf of Maine Atlantic Herring Purse Seine Fishery - MMPA List of Fisheries,”

https://www.fisheries.noaa.gov/national/marine-mammal-protection/gulf-maine-atlantic-herring-purse-seine-fisherymmpa-list.

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form.116 The Secretary of Commerce may suspend or revoke an authorization and may charge

fees for those authorizations.117 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.118 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.119 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.120

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.121 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.122 Additionally, these plans can be

created for any other marine mammal stocks that interact with a Category I commercial fishery.123

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.124 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.125

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.126

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

116 16 U.S.C. §1387(c)(2)-(3); NOAA, NMFS, “Marine Mammal Authorization Program,”

https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-authorization-program.

117 16 U.S.C. §1387(c)(4).

118 16 U.S.C. §1387(c)(3).

119 16 U.S.C. §§1387(c)(3)(B), 1387(d).

120 16 U.S.C. §1387(e).

121 16 U.S.C. §1387(f).

122 16 U.S.C. §1387(f)(1).

123 16 U.S.C. §1387(f)(1).

124 16 U.S.C. §1387(f)(2).

125 16 U.S.C. §1387(f)(2).

126 16 U.S.C. §1387(f)(4)(A)-(D).

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a region or fishery.127 For example, the Atlantic Large Whale Take Reduction Team addresses

North Atlantic right whales (NARWs), 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.128

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.129 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.130 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.131 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 2023.132 This action was taken to

reduce the threat of incidental mortality and serious injury to NARWs from lobster and Jonah

crab trap/pot fisheries, for which there is a high risk of overlap and entanglement.133 There has

been litigation related to this issue.134

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.135 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.136 For example, the ALWTRP includes gear making requirements for lobster and Jonah

127 16 U.S.C. §1387(f)(6).

128 NOAA, NMFS, “Atlantic Large Whale Take Reduction Team,” https://www.fisheries.noaa.gov/new-england-mid-

atlantic/marine-mammal-protection/atlantic-large-whale-take-reduction-team; NOAA, NMFS, “Atlantic Large Whale

Take Reduction Plan,” https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-mammal-protection/atlanticlarge-whale-take-reduction-plan.

129 16 U.S.C. §1387(g).

130 16 U.S.C. §1387(g)(2).

131 16 U.S.C. §1387(g)(1)(A)-(C).

132 NOAA, NMFS, “Taking of Marine Mammals Incidental to Commercial Fishing Operations; Atlantic Large Whale

Take Reduction Plan Regulations,” 88 Federal Register 7362-7369, February 3, 2023. Hereinafter NOAA, NMFS, 88

Federal Register 7362-7369.

133 NOAA, NMFS, 88 Federal Register 7362-7369.

134 For example, see Gabrielle Benjamin and Read Porter, Understanding the North Atlantic Right Whale Litigation,

Marine Affairs Institute at Roger Williams University School of Law, Rhode Island Sea Grant Legal Program, Maine

Sea Grant, June 2021, pp. 1-16, https://seagrant.gso.uri.edu/wp-content/uploads/2021/07/Understanding-the-NorthAtlantic-Right-Whale-Litigation-FINAL.pdf; and Penobscot Bay Pilot, “Federal Court of Appeals Rules in Favor of

Maine Lobstermen in Right Whale Case,” June 16, 2023, https://www.penbaypilot.com/article/federal-court-appealsrules-favor-maine-lobstermen-right-whale-case/175215.

135 As included under §111 of the MMPA. 16 U.S.C. §1381. The statute, under 16 U.S.C. §1381(a), states that the

program is to reduce the incidental taking of marine mammals in connection with commercial fishing to “the maximum

extent practicable.”

136 16 U.S.C. §1381(b); These regulations have been in effect since August 30, 1995. 50 C.F.R. §§229.1-229.37.

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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.137 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.138

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.139 The Secretary may provide these

funds following review by the MMC.140

Parallels Between the MMPA and the Magnuson-Stevens Fishery Conservation

and Management Act

Both the Marine Mammal Protection Act (MMPA; P.L. 92-522; 16 U.S.C. §§1361-1423h) and the Magnuson-Stevens

Fishery Conservation and Management Act (MSA; 16 U.S.C. §1801 et seq.) include provisions related to

commercial fisheries and nontarget catch, including marine mammals. Sections 101 and 118 of the MMPA

authorize the Secretary of Commerce to manage incidental takes of marine mammals in commercial fisheries,

including reducing those takes to the lowest practicable level and with a zero-mortality rate goal.

The MSA includes provisions about nontarget catch, bycatch reduction agreements and incentives (16 U.S.C.

§§1822(h), 1862(f)-(g)), and a Bycatch Reduction Engineering Program (16 U.S.C. §1865) administered by the

National Oceanic and Atmospheric Administration (NOAA), as well as provisions for the monitoring of

commercial fisheries bycatch (16 U.S.C. §§1821(h)(2)(B), 1822(e)(1)(A), 1881a(b)(2)). Provisions with respect to

international bycatch reduction agreements and regarding nontarget catch, as codified through the High Seas

Driftnet Moratorium Protection Act (P.L. 104-43), also include living marine resources (e.g., marine mammals; 16

U.S.C. §1826k). Marine mammal entanglements with fishing gear are included in NOAA national bycatch reports.

Each fishery management plan (FMP) produced by regional fishery management councils also is required to include

a standardized reporting methodology to assess the amount and type of bycatch occurring in that fishery, with

conservation and management measures for its minimization (16 U.S.C. §1853(a)(11)). FMPs also may include

conservation and management measures that provide harvest incentives to fishers that employ fishing practices

that result in lower levels of bycatch or mortality of bycaught species (16 U.S.C. §1853(b)(10)). Furthermore, the

MSA specifies areas of federal fisheries research that include the development and testing of new gear technology

and fishing techniques to minimize bycatch, including incidental harvest research and a bycatch reduction program

(16 U.S.C. 1881d(d)).

Sources: 16 U.S.C. §§1371(a)(2), 1387; 1821(h)(2)(B), 1822(e)(1)(A), 1822(h), 1826k, 1853(a)(11), 1853(b)(10),

1862(f)-(g), 1865, 1881a(b)(2), 1881d(d); NOAA, NOAA Fisheries Glossary, NOAA Technical Memorandum NMFSF/SPO-69, June 2006, p. 5, https://repository.library.noaa.gov/view/noaa/12856; NOAA, NMFS, “National Bycatch

Report,” https://www.fisheries.noaa.gov/resource/document/national-bycatch-report.

Notes: The MSA, under 16 U.S.C. §1802(2), defines bycatch as “fish which are harvested in a fishery, but which

are not sold or kept for personal use, and includes economic discards and regulatory discards. Such term does not

include fish released alive under a recreational catch and release fishery management program.” NOAA’s definition

of bycatch reduction (excluder) device extends the bycatch definition in the context of its reduction to include

“unwanted (nontarget and prohibited) species (e.g., jellyfish), smaller fish (juveniles), and threatened or endangered

species (e.g., sea turtles, marine mammals).”

137 50 C.F.R. §§229.32(b)-(c).

138 16 U.S.C. §1381(d). The statute also states that the Secretary provides the cost for quartering and maintaining those

agents.

139 16 U.S.C. §1380(a).

140 16 U.S.C. §1380(b).

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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.141

Federal Cooperation with States

All marine mammals in U.S. waters are managed under federal jurisdiction.142 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.143 Congress authorized the

Secretary to transfer the authority for the conservation and management of marine mammals to a

state where the species inhabits.144 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.145

For example, certain Hawaiian marine mammals, such as Hawaiian monk seals, humpback

whales, and several species of dolphins, also remain protected under Hawaii state laws.146 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.147 HDLNR

retained its management responsibilities, including for those species included under federal acts,

as included under Hawaii state laws.148

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.149 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.150 The MMPA provisions are deemed to be in addition to, and not

141 16 U.S.C. §§1378-1379, 1383. MMPA §108 (16 U.S.C. §1378) is entitled “International Program” and focuses on

international agreements, including (1) the duties of the Secretary, (2) consultations and studies concerning North

Pacific fur seals, and (3) reporting and proposed actions regarding discussions with foreign governments on marine

mammals and yellowfin tuna fisheries.

142 NOAA, NMFS, “Laws and Policies: Marine Mammal Protection Act.”

143 16 U.S.C. §1379(a).

144

MMPA §109. 16 U.S.C. §1379(a).

145 16 U.S.C. §1379(a).; 50 C.F.R. §§403.01-403.08.

146 State of Hawaii Department of Land and Natural Resources (HDLNR), Division of Boating and Ocean Recreation,

“Protecting Marine Species,” https://dlnr.hawaii.gov/dobor/protecting-marine-species/ (hereinafter, HDLNR,

“Protecting Marine Species”).

147 NOAA, NMFS, Recovery Plan for the Hawaiian Monk Seal (Monachus schauinslandi), August 22, 2007, pp. I-2,

https://repository.library.noaa.gov/view/noaa/3521. Hereinafter NOAA, NMFS, Recovery Plan for the Hawaiian Monk

Seal.

148 NOAA, NMFS, Recovery Plan for the Hawaiian Monk Seal; HDLNR, “Protecting Marine Species”; for example,

HRS §195D-4.5 prohibits the taking of Hawaiian monk seals.

149 As included under MMPA §108. 16 U.S.C. §1378.

150 16 U.S.C. §1378(a)(1)-(2).

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in contravention of, the provisions of any existing international treaty, convention, agreement, or

statute that applies to the taking of marine mammals.151

In accordance with Section 101(a)(2) of the MMPA, the United States is to prohibit imports of

seafood (or seafood products) captured with commercial fishing technologies that result in the

incidental mortality or serious injury of marine mammals in excess of U.S. standards.152 In

September 2025, NMFS published marine mammal comparability findings (i.e., certifications of

comparable marine mammal standards to those of the United States) for over 100 nations that

export seafood to the United States (effective date January 1, 2026), including denials and import

restrictions for multiple fisheries.153 There has been litigation related to these comparability

findings for certain swimming crab fisheries.154

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.155 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.156 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,157 and for the Bering Sea ecosystem.158

151 MMPA §113. 16 U.S.C. §1383(a). The MMPA does not directly specify if the United States must be a signatory to

each treaty, convention, agreement, or statute.

152 16 U.S.C. §1371(a)(2).

153 According to NMFS, comparability findings were initially denied for a total of 240 fisheries from 46 nations.

NOAA, NMFS, “Marine Mammal Protection Act Comparability Finding Determinations for Harvesting Nations,”

https://www.fisheries.noaa.gov/international-affairs/marine-mammal-protection-act-comparability-findingdeterminations-harvesting; and NOAA, NMFS, “Implementation of Fish and Fish Product Import Provisions of the

Marine Mammal Protection Act-Notification of Comparability Findings and Implementation of Import Restrictions;

Certification of Admissibility for Certain Fish Products,” 90 Federal Register 42395-42398, September 2, 2025.

154 NOAA, NMFS, “Notice of Reconsideration of Comparability Findings for Swimming Crab Fisheries,”

https://www.fisheries.noaa.gov/action/notice-reconsideration-comparability-findings-swimming-crab-fisheries; and

NOAA, NMFS, “Implementation of Fish and Fish Product Import Provisions of the Marine Mammal Protection

Action-Notification of Comparability Findings,” 91 Federal Register 25867-25868, May 12, 2026.

155 16 U.S.C. §1380(c)-(d).

156 16 U.S.C. §§1388-1389. These task forces are to account for interactions between fisheries and pinnipeds (i.e., seals

and sea lions), including concerns about pinniped predation on certain Pacific salmon stocks and potential impacts to

seafood species reared through aquaculture in the Gulf of Maine.

157 16 U.S.C. §1380(c). The Secretary of Commerce, in consultation with the MMC, adjacent coastal states, and experts

from multiple backgrounds, convened a 1995 workshop to assess human-caused factors affecting the health and

stability of the Gulf of Maine ecosystem. Workshop participants recommended interdisciplinary research and integrated

management approaches, including those for marine mammals, that identify linkages between ecosystem components

and their sensitivity and resilience to stressors. 16 U.S.C. §1380(c); David Dow and Eugenia Braasch, eds., The Health

of the Gulf of Maine Ecosystem: Cumulative Impacts of Multiple Stressors, Regional Association for Research on the

Gulf of Maine, under contract from NOAA NMFS, Workshop Report, Dartmouth College, RARGOM Report 96-1,

Hanover, NH, April 30, 1996, http://www.gulfofmaine.org/resources/gomc-library/

health%20of%20gom%20ecosystem%20cumulative%20impacts_workshop%20report.pdf.

158 16 U.S.C. §1380(d). Congress required the Secretary of Commerce, in consultation with the Secretary of the

Interior, MMC, the State of Alaska, and Alaska Native organizations, to undertake a scientific research program to

monitor the health and stability of the Bering Sea marine ecosystem, including marine mammals. In years since, federal

agencies and partners have developed several ecosystem-based monitoring programs for the Bering Sea region, such as

(continued...)

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•

Section 119 includes provisions with respect to marine mammal cooperative

agreements in Alaska.159

Section 120 includes provisions with respect to the Pacific Coast and Gulf of

Maine Task Forces, which are tasked to investigate pinniped-fishery interactions

(e.g., consumption of ESA-listed Pacific salmon and steelhead trout by sea

lions).160

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.161 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.162

As prescribed in the MMPA, the program is to

the NOAA Bering Sea Ecosystem Assessments, the National Science Foundation 2005 Bering Ecosystem Study

(BEST), and the North Pacific Research Board Bering Sea Integrated Ecosystem Research Program (BSIERP). The

Secretary and the MMC are to include the status and findings of these research programs in their annual reports to

Congress. NOAA, NMFS, “Southeastern Bering Sea Ecosystem Assessment,” https://www.fisheries.noaa.gov/alaska/

ecosystems/southeastern-bering-sea-ecosystem-assessment; NOAA, NMFS, “Northeastern Bering Sea Ecosystem

Assessment,” https://www.fisheries.noaa.gov/alaska/ecosystems/northeastern-bering-sea-ecosystem-assessment;

NOAA, NMFS, “Understanding Ecosystem Processes in the Bering Sea: First Year Field Highlights from the BESTBSIERP Partnership,” https://apps-afsc.fisheries.noaa.gov/Quarterly/amj2009/AMJ09featurelead.htm; North Pacific

Research Board, “The Bering Sea Research Project,” https://nprb.org/bering-sea-project/.

159 16 U.S.C. §§1388(a)-(b). These agreements allow the Secretary to enter into cooperative agreements with Alaska

Native organizations to conserve marine mammals and to provide comanagement of subsistence use by Alaska Natives.

The cooperative agreements also may include grants to Alaska Native organizations to collect and analyze data on

marine mammal populations, monitor their harvest, participate in marine mammal research, and develop marine

mammal comanagement structures with federal and state agencies.

160 §120(a)-(f) allow the Secretary of Commerce to permit the intentional, humane, lethal taking of pinnipeds that are

having a significant negative impact on the recovery of salmonid fishery stocks listed under the Endangered Species

Act [16 U.S.C. §§1531-1544] in the waters of the Columbia River and its tributaries. Eligible entities for permits

include the states of Washington, Oregon, and Idaho and specified tribes. 16 U.S.C. §1389(a)-(f); §120(h) also includes

provisions for a Gulf of Maine task force to advise the Secretary on issues or problems regarding pinnipeds interacting

in a dangerous or damaging manner with aquaculture resources in the Gulf of Maine. 16 U.S.C. §1389(h). For

additional information, see CRS In Focus IF11045, Sea Lion Predation on Columbia River Salmon and Steelhead, by

Anthony R. Marshak.

161 16 U.S.C. §1421-1421h. The MMPA, under 16 U.S.C. §1421h(6), defines stranding as

an event in the wild in which—(A) a marine mammal is dead and is—(i) on a beach or shore of the

United States; or (ii) in waters under the jurisdiction of the United States (including any navigable

waters); or (B) a marine mammal is alive and is—(i) on a beach or shore of the United States and

unable to return to the water; (ii) on a beach or shore of the United States and, although able to

return to the water, is in need of apparent medical attention; or (iii) in the waters under the

jurisdiction of the United States (including any navigable waters), but is unable to return to its

natural habitat under its own power or without assistance.

162 16 U.S.C. §1421(a); The MMPA, under 16 U.S.C. §1421h(7), defines a stranding network participant as a person

who is authorized by an agreement under 16 U.S.C. §1382(c) to take marine mammals as described in 16 U.S.C.

§1379(h)(1) in response to a stranding.

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•

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.163

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”).164

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.165 Network participants provide staff and local response

capabilities, and they independently raise funds to cover the majority of their costs.166 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.167 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.168 The Secretary is to make that information available

to researchers, stranding network participants, and the public.169

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.170 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.171 The Secretary also is to maintain a central, publicly accessible database with that

information.172 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.173 The Secretary may grant

emergency financial assistance for stranding events or entanglements that occur to marine

mammals under the Secretary’s jurisdiction.174

163 16 U.S.C. §1421(b), 1421c; The MMPA, under 16 U.S.C. §1421h(9), defines an unusual mortality event as “a

stranding that (A) is unexpected; (B) involves a significant die-off of any marine mammal population; and (C) demands

immediate response.”

164 NOAA, NMFS, “Marine Mammal Health and Stranding Response Program,” https://www.fisheries.noaa.gov/

national/marine-life-distress/marine-mammal-health-and-stranding-response-program (hereinafter, NOAA, NMFS,

“Marine Mammal Health and Stranding Response Program”).

165 NOAA, NMFS, “Marine Mammal Health and Stranding Response Program.”

166 NOAA, NMFS, “Marine Mammal Health and Stranding Response Program.”

167 16 U.S.C. §1421a(b).

168 16 U.S.C. §1421a(c).

169 16 U.S.C. §1421a(d).

170 16 U.S.C. §1421f.

171 16 U.S.C. §1421f(a)(3).

172 16 U.S.C. §1421f(c)-(d).

173 16 U.S.C. §1421f-1.

174 16 U.S.C. §§1421f-1, 1421f-1(a)(1).

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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),175 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.176

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.177 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.178

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.179

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.180 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.181

The MMPA also established the Marine Mammal Unusual Mortality Event Fund in the U.S.

Treasury.182 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.183 The Secretary also may accept, solicit, and use the services

of volunteers and may accept and solicit donations for this fund.184

175 16 U.S.C. §1421c.

176 16 U.S.C. §1421c(a)(1)(A).

177 16 U.S.C. §1421c(a)(2)(A).

178 16 U.S.C. §1421c(a)(2)(B).

179 16 U.S.C. §1421c(c)(1)-(2).

180 16 U.S.C. §1421c(b).

181 16 U.S.C. §1421c(b)(2).

182 16 U.S.C. §1421d.

183 16 U.S.C. §1421d(b).

184 16 U.S.C. §1421d(d).

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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.185 Other experts and stakeholders have considered if and how MMPA provisions

align with holistic ecosystem-based management efforts relating to multiple ocean uses (e.g.,

fishing, marine transportation, marine construction).186 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.187 Additionally, experts suggest that increased

predation on southern sea otters has resulted from northward distribution shifts of white sharks

associated with warming ocean temperatures.188 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,189 which may affect certain populations and their

abundance.190 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.191

185 Gulland et al., “Climate Change Effects on Marine Mammals”; Bradley Varner, Reviewing the Marine Mammal

Protection Act Through a Modern Lens, Michigan State University Animal Legal and Historical Center, 2022,

https://www.animallaw.info/article/reviewing-marine-mammal-protection-act-through-modern-lens#id-8.

186 Christian Riisager-Simonsen et al., “Using Ecosystem-Services Assessments to Determine Trade-Offs in

Ecosystem-Based Management of Marine Mammals,” Conservation Biology, vol. 34, no. 5 (2020), pp. 1152-1164

(hereinafter, Riisager-Simonsen et al., “Using Ecosystem-Services Assessments”); David Fluharty, “Chapter 12:

Ecosystem-Based Approaches to Ocean Management in the United States: Weaving Together Multiple Strands,” in The

Ecosystem Approach in Ocean Planning and Governance, eds. David Langlet and Rosemary Rayfuse (Leiden, The

Netherlands: Koninklijke Brill NV, 2019), pp. 371-412 (hereinafter, Fluharty, “Ecosystem-Based Approaches to Ocean

Management”).

187 Gulland et al., “Climate Change Effects on Marine Mammals.”

188 Gulland et al., “Climate Change Effects on Marine Mammals.”

189 NOAA’s National Ocean Service (NOS) defines upwelling as “a process in which deep, cold water rises toward the

surface.” NOAA, NOS, “What is Upwelling,” https://oceanservice.noaa.gov/facts/upwelling.html.

190 Gulland et al., “Climate Change Effects on Marine Mammals”; NOAA, NMFS, “2019-2023 Eastern North Pacific

Gray Whale UME (Closed)”; and Ian M. Stevenson, “Dozens of Starving Gray Whales are Washing Up on Pacific

Coast,” E&E Greenwire, June 3, 2026, https://subscriber.politicopro.com/article/eenews/2026/06/03/dozens-ofstarving-gray-whales-are-washing-up-on-pacific-coast-00947181.

191 Gulland et al., “Climate Change Effects on Marine Mammals”; Anthony M. Pagano and Terrie M. Williams,

“Physiological Consequences of Arctic Sea Ice Loss on Large Marine Carnivores: Unique Responses by Polar Bears

and Narwhals,” Journal of Experimental Biology, vol. 224, Suppl. 1 (2021), jeb228049, pp. 1-13; Anthony M. Pagano

(continued...)

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Additionally, NMFS and partners have identified “high” or “very high” vulnerabilities to climate

change for approximately 75% of the 108 Atlantic marine mammal stocks (e.g., pinnipeds,

dolphins, whales) they examined.192 According to NMFS, climate vulnerability assessments for

Pacific marine mammal stocks are ongoing as of June 2026.193

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.194 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.195 They have noted that refinements to the MMPA or additional legislation similar to the

MMPA are important, given these ongoing threats.196 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.197 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.198

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. 8496, introduced in the 119th 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.199 Among its contents, 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. Similar legislation (H.R. 1383) was introduced in the 118th Congress.

et al., “Effects of Sea Ice Decline and Summer Land Use on Polar Bear Home Range Size in the Beaufort Sea,”

Ecosphere, vol. 12, no. 10 (2021), e03768, pp. 1-19.

192 Lettrich et al., “Vulnerability to Climate Change.”

193 NOAA, NMFS, “Climate Vulnerability Assessments—Current Climate Vulnerability Assessments,”

https://www.fisheries.noaa.gov/national/climate-change/climate-vulnerability-assessments#current-climatevulnerability-assessments.

194 Lettrich et al., “Vulnerability to Climate Change”; International Marine Mammal Project, “Climate Change Impacts

on Marine Mammals,” https://savedolphins.eii.org/news/climate-change-impacts-on-marine-mammals; U.S. Congress,

Senate Committee on Commerce, Science, and Transportation, Subcommittee on Oceans, Fisheries and Coast Guard,

Future of the Marine Mammal Protection Act, 108th Cong., 1st sess., July 16, 2003, S. Hrg. 108-981.

195 U.S. Congress, Senate Committee on Commerce, Science, and Transportation, Subcommittee on Oceans, Fisheries

and Coast Guard, Future of the Marine Mammal Protection Act, 108th Cong., 1st sess., July 16, 2003, S. Hrg. 108-981.

Hereinafter U.S. Congress, Future of the Marine Mammal Protection Act, 2003.

196 U.S. Congress, Future of the Marine Mammal Protection Act, 2003.

197 Roman et al., “Marine Mammal Protection Act at 40”; Gulland et al., “Climate Change Effects on Marine

Mammals.”

198 Roman et al., “Marine Mammal Protection Act at 40”; Gulland et al., “Climate Change Effects on Marine

Mammals.”

199 Similar legislation was introduced in previous Congresses (H.R. 3692 in the 117th and H.R. 8795 in the 116th).

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The Marine Mammal Protection Act: Primer and Issues for Congress

H.R. 3764, introduced in the 117th Congress and as reported in the House, 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.200 It remains unclear how these agency priorities may have changed

since 2021. Both agencies recommended incorporating the climate impact plan requirements into

existing plans and minimizing duplicative approaches for marine mammal conservation.201

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.202 Some Members of Congress have

expressed concerns about provisions in H.R. 3692, introduced in the 117th 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.203 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. Questions about the accuracy of marine mammal population projections also may be

relevant to the 119th Congress.204

200 U.S. Congress, House Committee on Natural Resources, Legislative Hearing on H.R. 660, “Shovel-Ready

Restoration Grants for Coastlines and Fisheries Act of 2021”; H.R. 1415, “Tribal Coastal Resiliency Act”; H.R. 1689,

“Offshore Wind for Terrirories Act”; H.R. 2750, “Blue Carbon for our Planet Act”; H.R. 3160, “Keep Americans’

Waterfronts Working Act”; H.R. 3228, “National Coastal Resilience Data and Services Act”; H.R. 3692, “Marine

Mammal Climate Change Protection Act”; H.R. 3748, “Blue Globe Act”; H.R. 3764, “Ocean-Based Climate Solutions

Act of 2021”; H.R. 3817, “Regional Ocean Partnership Act”; H.R. 3864, “Chesapeake Bay Oyster Research Act”;

H.R. 3892, “National Oceans and Coastal Security Improvements Act”; and H.R. 3906, “Blue Carbon Protection

Act,” 117th Cong., 1st sess., June 22, 2021, Serial No. 117-6 (GPO, 2021), pp. 1-129 (hereinafter, U.S. Congress, House

Committee on Natural Resources, Legislative Hearing).

201 U.S. Congress, House Committee on Natural Resources, Legislative Hearing.

202 Roman et al., “Marine Mammal Protection Act at 40”; Gulland et al., “Climate Change Effects on Marine

Mammals.”

203 U.S. Congress, House Committee on Natural Resources, Legislative Hearing.

204 U.S. Congress, House Committee on Natural Resources, Legislative Hearing.

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The Marine Mammal Protection Act: Primer and Issues for Congress

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.205 Since the

MMPA’s enactment, federal agencies have implemented ecosystem-based management

approaches that consider multiple ocean sectors and living marine resources and have conducted

integrated assessments to inform these practices.206

Stakeholders and federal agencies have noted that the MMPA was the first legislation to mandate

an ecosystem-based approach to managing marine resources.207 NOAA has emphasized that the

MMPA shifted the focus of conservation from species to ecosystems and included protection for

population stocks, species, and subspecies.208 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.209

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.210 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.211

Alternatively, other stakeholders have expressed concerns about the complexity, costs, and

administrative challenges associated with ecosystem-based management approaches.212 Some

205 For example, 16 U.S.C. §§1361(2), 1361(5), 1373(b)(3).

206 NOAA, “Integrated Ecosystem Assessment (IEA)—Ecosystem-Based Management,”

https://www.integratedecosystemassessment.noaa.gov/about-iea/ecosystem-based-management.

NOAA defines ecosystem-based management as

an approach that takes major ecosystem components and services—both structural and functional—

into account in managing fisheries. It values habitat, embraces a multispecies perspective, and is

committed to understanding ecosystem processes. Its goal is to rebuild and sustain populations,

species, biological communities, and marine ecosystems at high levels of productivity and

biological diversity so as not to jeopardize a wide range of goods and services from marine

ecosystems while providing food, revenue, and recreation for humans.

NOAA, NOAA Fisheries Glossary, NOAA Technical Memorandum NMFS-F/SPO-69, 2006, pp. 11-12,

https://repository.library.noaa.gov/view/noaa/12856.

207 NOAA, NMFS, “Laws & Policies: Marine Mammal Protection Act,” https://www.fisheries.noaa.gov/topic/lawspolicies/marine-mammal-protection-act (hereinafter, NOAA, NMFS, “Laws and Policies: Marine Mammal Protection

Act”); National Marine Sanctuary Foundation, “50 Years of Ocean [and] Coastal Conservation: Marine Mammal

Protection Act,” https://marinesanctuary.org/blog/50-years-of-ocean-coastal-conservation-marine-mammal-protectionact/.

208 NOAA, NMFS, “Laws and Policies: Marine Mammal Protection Act”; the MMPA defines population stock as “a

group of marine mammals of the same species or smaller taxa in a common spatial arrangement that interbreed when

mature.”

209 NOAA, NMFS, “Laws and Policies: Marine Mammal Protection Act.”

210 Riisager-Simonsen et al., “Using Ecosystem-Services Assessments”; Fluharty, “Ecosystem-Based Approaches to

Ocean Management.”

211 U.S. Congress, Senate Committee on Commerce, Science, and Transportation, Subcommittee on Oceans, Fisheries

and Coast Guard, Future of the Marine Mammal Protection Act, 108th Cong., 1st sess., July 16, 2003, S. Hrg. 108-981.

212 Ayeisha A. Brinson and Kristy Wallmo, “Stakeholder Attitudes Toward Ecosystem-Based Fisheries Management,”

Marine Fisheries Review, vol. 77, no. 3 (December 2015), pp. 17-30; Anthony R. Marshak et al., “International

Perceptions of an Integrated, Multi-sectoral, Ecosystem Approach to Management,” ICES Journal of Marine Science,

vol. 74, no. 1 (2017), pp. 414-420.

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stakeholders and Members of Congress also have voiced concerns about potential economic

impacts to marine sectors from certain marine mammal protections;213 some experts suggest that

ecosystem-based management may provide more cost-effective approaches when accounting for

these and other trade-offs.214

If Congress considers 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 117th 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. Congress has recurrently

discussed amending the MMPA, such as in a July 2025 discussion draft proposing comprehensive

MMPA amendments (e.g., regarding incidental takes of marine mammals by fishing and

nonfishing sectors).215 In considering any proposed amendments to the MMPA, Congress may

examine whether provisions might pertain to particular ocean sectors and/or their cumulative

interactions with 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. 117103), and Consolidated Appropriations Act, 2023 (P.L. 117-328).216 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.”217

Congress also could consider additional oversight such as that included in H.R. 1056 during the

118th 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

213 Rob Hotakainen, “Senate Republicans Urge NOAA to Scrap Rice's Whale Protections,” E&E Daily, May 7, 2024,

https://www.eenews.net/articles/senate-republicans-urge-noaa-to-scrap-rices-whale-protections/; National Marine

Manufacturers Association, “Recreational Boating Industry Decries Advancement of Vessel Speed Rule,” March 7,

2024; Darren Incorvaia, “Recreational Fishing Industry Won't Slow Down for Right Whales,” Undark, March 29,

2023, https://undark.org/2023/03/29/recreational-fishing-industry-wont-slow-down-for-right-whales/.

214 For example, Jason S. Link and Janne B. Haugen, “The Business Case for Ecosystem-Based Management,” Marine

Policy, 2025, 106485.

215 U.S. Congress, House Natural Resources Committee, Water, Wildlife and Fisheries Subcommittee, [Discussion

Draft] H.R. _____, A Bill to amend the Marine Mammal Protection Act of 1972 to [_____], 119th Cong., 1st sess., July

7, 2025, pp. 1-32, https://docs.house.gov/meetings/II/II13/20250722/118447/BILLS-119pih-DiscussionDraft.pdf.

Discussed during U.S. Congress, House Natural Resources Committee, Water, Wildlife and Fisheries Subcommittee,

Legislative Hearing on H.R. 180, H.R. 3706, H.R. 3831, H.R. 4033, H.R. 4293, H.R. 4294 and a Discussion Draft,

119th Cong., 1st sess., July 22, 2025, https://naturalresources.house.gov/calendar/eventsingle.aspx?EventID=418269.

216 “Explanatory Statement Submitted by Ms. DeLauro, Chair of the House Committee on Appropriations, Regarding

the House Amendment to the Senate Amendment to H.R. 2471, Consolidated Apporpriations Act, 2022,”

Congressional Record, vol. 168, part 42-Book III (March 9, 2022), p. H1776; “Explanatory Statement Submitted by

Mr. Leahy, Chair of the Senate Committee on Appropriations, Regarding H.R. 2617, Consolidated Appropriations Act,

2023,” Congressional Record, vol. 168, part 198 (December 20, 2022), p. S7908.

217 “Explanatory Statement Submitted by Mr. Leahy, Chair of the Senate Committee on Appropriations, Regarding

H.R. 2617, Consolidated Appropriations Act, 2023,” Congressional Record, vol. 168, part 198 (December 20, 2022), p.

S7908.

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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.218

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

agencies.

Congress also may consider whether to retain, expand upon, or constrain present programs

established in other statutes, such as the Don Young Coast Guard Authorization Act of 2022

(CGAA of 2022; P.L. 117-263, Division K, Title CXIII), which primarily address impacts of

vessel traffic on marine mammals.219 For example, in the Coast Guard Authorization Act of 2025

(P.L. 119-60, Division G, Title LXXIII, Subtitle E, Section 7344), Congress extended the Puget

Sound cetacean desk pilot program, established in the CGAA of 2022, through December 31,

2029.220 NOAA and the National Fish and Wildlife Foundation (NFWF) also administer the

Vessel Strike Avoidance Fund, which has supported projects through general funding authorities

to NOAA in the FY2022 reconciliation law commonly known as the Inflation Reduction Act (P.L.

117-169, Section 40001).221 These programs were created outside of MMPA provisions, which

may provide a legislative alternative to directly amending the MMPA with respect to marine

mammal interactions with certain sectors.222 Congress may consider whether these programs

might serve as examples for others that could address marine mammal interactions with

individual or multiple marine sectors, including whether cumulative approaches may be

applicable. Congress also may consider whether to authorize these or similar programs as

provisions in the MMPA. Congress also may determine if sufficient protections are currently in

place for marine mammals and may take no additional action.

218 National Academies of Sciences, Engineering, and Medicine, Approaches to Understanding the Cumulative Effects

of Stressors on Marine Mammals (Washington, DC: The National Academies Press, 2017), pp. 1-98,

https://nap.nationalacademies.org/catalog/23479/approaches-to-understanding-the-cumulative-effects-of-stressors-onmarine-mammals.

219 Among its contents, the Don Young Coast Guard Authorization Act of 2022 (P.L. 117-263, Division K, Title CXIII)

established assistance to ports to reduce impacts of vessel traffic and port operations on marine mammals (16 U.S.C.

§1390), a pilot cetacean desk program for the Puget Sound region (16 U.S.C. §1390 note), and a near real-time

monitoring and mitigation program for large cetaceans to minimize risks of vessel collisions (16 U.S.C. §1391).

220 As stipulated in the Don Young Coast Guard Authorization Act of 2022, under 16 U.S.C. §1390 note, the U.S.

Coast Guard (USCG) Cetacean Desk pilot program is designed “(i) to improve coordination with the maritime industry

to reduce the risk of vessel impacts on large cetaceans, including impacts from vessel strikes, disturbances, and other

sources; and (ii) to monitor the presence and location of large cetaceans during the months during which such large

cetaceans are present in Puget Sound, the Strait of Juan de Fuca, and the United States portion of the Salish Sea.” U.S.

Coast Guard (USCG)—Pacific Area, “USCG Cetacean Desk,” https://www.pacificarea.uscg.mil/OurOrganization/Northwest-District/Units/Sector-Puget-Sound/VTS-Puget-Sound/USCG-Cetacean-Desk/.

221 National Fish and Wildlife Foundation (NFWF), “Vessel Strike Avoidance Fund,” https://www.nfwf.org/programs/

vessel-strike-avoidance-fund; and NFWF, “NFWF and NOAA Announce Vessel Strike Avoidance Fund 2024 Request

for Proposals,” May 22, 2024, https://www.nfwf.org/media-center/press-releases/nfwf-and-noaa-announce-vesselstrike-avoidance-fund-2024-request. Section 40008 of P.L. 119-21, commonly known as the One Big Beautiful Bill Act

(OBBBA), rescinded unobligated balances of amounts made available to NOAA under P.L. 117-169. At this time, it is

unclear how much funding was rescinded.

222 H.R. 3764 in the 117th Congress (under Title VII) proposed similar programs as separate statutory provisions and

proposed other related programs as amendments to the MMPA.

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The Marine Mammal Protection Act: Primer and Issues for Congress

Trade-Offs Between Marine Mammal Conservation and U.S.

Fisheries

Trade-offs between MMPA-implemented conservation and protection efforts and their impacts on

U.S. 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.223 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.224 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.225 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.226 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.227 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.228 Further, with respect to authorized lethal removals of

pinnipeds preying on salmon and steelhead trout populations, some stakeholders have highlighted

ongoing capacity and funding needs for their effective implementation in portions of the

Columbia River basin.229 Other stakeholders have objected to the use of lethal removals to

address pinniped predation given additional stressors affecting salmonids (e.g., habitat

fragmentation) and factors such as climate change, hydropower, and availability of other prey

223 Ed Komenda, “Oregon Crabbers and Environmentalists Are at Odds as a Commission Votes on Rules to Protect

Whales,” Associated Press, August 4, 2023, https://apnews.com/article/oregon-whale-entanglements-crabbing-rules02ad8b9ca27359eb1f395e1d347357b9 (hereinafter Komenda, “Oregon Crabbers and Environmentalists Are at Odds”);

Rob Hotakainen, “NOAA Broke Law by Not Protecting Right Whales, Judge Rules,” E&E News Greenwire, June 11,

2022, https://www.eenews.net/articles/noaa-broke-law-by-not-protecting-right-whales-judge-rules/ (hereinafter

Hotakainen, “NOAA Broke Law”); Kirk Moore, “Federal Judge Turns Down Lobstermen’s Attempt to Block Right

Whale Rules,” National Fisherman, September 9, 2022, https://www.nationalfisherman.com/northeast/federal-judgeturns-down-lobstermen-s-attempt-to-block-right-whale-rules.

224 As examples, Komenda, “Oregon Crabbers and Environmentalists Are at Odds”; Hotakainen, “NOAA Broke Law.”

225 Kimberly L. Oremus et al., “Underfished or unwanted? Much blame cast upon fisheries policy may be misguided,”

Science, vol. 380, no. 6645 (2023), pp. 585-588.

226 R. C. Fletcher, “Exploding Populations of California Sea Lions: A Crisis with No Political Solution on the

Horizon,” Proceedings of the Vertebrate Pest Conference, vol. 23, no. 23 (2008), pp. 178-180 (hereinafter Fletcher,

“Exploding Populations”); House Committee on Natural Resources, “Investigating Sea Lion Predation in the Pacific

Northwest,” press release, December 3, 2025, https://naturalresources.house.gov/news/documentsingle.aspx?

DocumentID=418491. For additional information, see CRS In Focus IF11045, Sea Lion Predation on Columbia River

Salmon and Steelhead, by Anthony R. Marshak.

227 Bellamy Paithorp, “Pacific Northwest Tribes Want a New Strategy to Manage Marine Mammals,” National Public

Radio, November 14, 2022, https://www.npr.org/2022/11/14/1136617285/pacific-northwest-tribes-want-a-newstrategy-to-manage-marine-mammals. Hereinafter Paithorp, “Pacific Northwest Tribes Want a New Strategy.”

228 Paithorp, “Pacific Northwest Tribes Want a New Strategy”; Fletcher, “Exploding Populations.”

229 For example, Testimony of Aja DeCoteau, executive director, Columbia River Inter-Tribal Fish Commission, in

U.S. Congress, House Natural Resources Committee, Subcommittee on Water, Wildlife and Fisheries, Sea Lion

Predation in the Pacific Northwest, December 3, 2025, pp. 1-10, https://docs.house.gov/meetings/II/II13/20251203/

118718/HHRG-119-II13-Wstate-DeCoteauA-20251203.pdf.

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types (e.g., herring preyed upon by seals and/or sea lions) potentially influencing pinniped

predation on salmonids.230

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.231 Additionally, interim provisions in the MMPA regarding exemptions for

commercial fisheries mandated that the Secretary account for these factors when prescribing

emergency regulations.232 Congress could specify these considerations further. For example, to

assist fishers in modifying their gears to minimize entanglement risk to North Atlantic right

whales (NARWs), H.R. 7042 and S. 3765, introduced in the 117th 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.233 Eligible uses of these funds include

“subsidizing acquisition of innovative gear technologies to improve adoption of those

technologies by fisheries participants.”234 NFWF and NOAA have administered a program

pursuant to these provisions since 2023.235 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. Further, Congress could consider the use of other

provisions outside the MMPA for managing these intersections, such as those with respect to the

management of the Northeast/Mid-Atlantic American lobster and Jonah Crab trap/pot fisheries

and their interactions with NARWs through December 2028, as stipulated in the Consolidated

Appropriations Act, 2023.236 Congress also may consider whether amendments to the MMPA

with respect to these factors may be warranted. Such amendments to the MMPA might allow for

longer-term authorization of certain programs and their inclusion as components of relevant

sections pertaining to fisheries (e.g., Section 118 of the MMPA).237 As marine mammal provisions

in other legislation (i.e., outside the MMPA) also may mandate NOAA and partners to address

trade-offs between marine mammals and fisheries, Congress may consider the utility of such

230 As examples, Lisa G. Crozier et al., “Climate Change Threatens Chinook Salmon Throughout Their Life Cycle,”

Communications Biology, vol. 4, no. 1 (2022), 222, pp. 1-14; U.S. Army Corps of Engineers, 2024 Evaluation of

Pinniped Predation on Adult Salmonids and Other Fish in the Bonneville Dam Tailrace, Cascade Locks, OR, March

2025, pp. 1-45; and Lauri Leach et al., “Examining the Impacts of Pinnipeds on Atlantic Salmon: The Effects of River

Restoration on Predator-Prey Interactions,” Aquatic Conservation: Marine and Freshwater Ecosystems, vol. 32, no. 4

(2022), pp. 645-657.

231

16 U.S.C. §1387(f)(2).

232 16 U.S.C. §1383a(g)(3); these interim provisions were in effect until the mid-1990s and are included under §114,

“Interim Exemption for Commercial Fisheries.” 16 U.S.C. §1383. They were replaced by §118, “Taking of Marine

Mammals Incidental to Commercial Fishing Operations.” 16 U.S.C. §1387.

233 Consolidated Appropriations Act, 2023, Legislative Text, Congressional Record, vol. 168, part 197 (December 19,

2022), pp. S7784-S7785.

234 16 U.S.C. §1393(c)(2).

235 National Fish and Wildlife Foundation, “New England Gear Innovation Fund,” https://www.nfwf.org/programs/

fisheries-innovation-fund/new-england-gear-innovation-fund?activeTab=tab-3.

236 P.L. 117-328, Division JJ, Title I, Section 101; 16 U.S.C. §1387 note. H.R. 8509 in the 119th Congress would amend

these provisions to extend their applicability through December 2035.

237 16 U.S.C. §1387.

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alternatives. Congress may also consider whether these alternative pathways might allow for

more expedient passage of marine mammal-related legislation compared to amending the MMPA.

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 NARWs.238 Members of 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 America and South Atlantic fisheries.239

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.240

Congress could consider similar provisions in the MMPA for the development of technologies

toward minimizing human-marine mammal conflicts for commercial fisheries. Congress also

could examine whether these types of information and protections for marine mammals are

sufficient and determine that no further action may be warranted.

Congress may also consider the utility of amending the MMPA to authorize funding for programs

addressing marine mammal conflicts with fisheries. For example, Congress may examine whether

a program providing assistance to states and tribal parties in carrying out lethal removals of

pinnipeds may be warranted (e.g., as an amendment to Section 120 of the MMPA), and whether

current state and tribal resources are sufficient for carrying out authorized removals. Congress

also may consider authorizing programs in support of nonlethal deterrents and technological

approaches for addressing these and other types of interactions between marine mammals and

fishery species, and the degree of their effectiveness. 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.241 Such studies, research, and oversight activities may inform Congress’s

decision on whether to consider amending the MMPA.

238 For example, “Explanatory Statement Submitted by Mr. Leahy, Chair of the Senate Committee on Appropriations,

Regarding H.R. 2617, Consolidated Appropriations Act, 2023,” Congressional Record, vol. 168, part No. 198

(December 20, 2022), pp. S7908-S7909; see also 16 U.S.C. §1393(c)(2).

239 U.S. Congress, House Committee on Appropriations, Consolidated Appropriations Act, 2021 on H.R. 133/P.L. 116220 [Legislative Text and Explanatory Statement] Book 1 of 2, Divisions A-F, committee print, 117th Cong., 1st sess.,

March 2021, H.Prt. 43-479, pp. 215-216.

240 16 U.S.C. §742b note; USFWS, “Theodore Roosevelt Genius Prize Competitions,” https://www.fws.gov/service/

theodore-roosevelt-genius-prize-competitions.

241 U.S. Congress, House Committee on Appropriations, Consolidated Appropriations Act, 2021 on H.R. 133/P.L. 116220 [Legislative Text and Explanatory Statement] Book 1 of 2, Divisions A-F, committee print, 117th Cong., 1st sess.,

March 2021, H.Prt. 43-479, p. 221.

Congressional Research Service

The Marine Mammal Protection Act: Primer and Issues for Congress

Author Information

Anthony R. Marshak

Analyst in Natural Resources Policy

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R47892 · VERSION 5 · UPDATED

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