Key provisions of the MMPA
A new perspective
Interactions between marine mammals and commercial fisheries
Strandings and unusual mortality events
Contaminants, noise, and other environmental threats
Looking forward

Marine Mammal Conservation and the Marine Mammal Protection Act*

Much of the past 40 years' history of marine mammal conservation is reflected in the background, content, implementation, and changes in the U. S. Marine Mammal Protection Act (MMPA) of 1972. The Act was one of a series of federal environmental laws enacted in the United States in the late 1960s and early 1970s in response to the then-growing awareness that human activities were threatening the natural resources and ecosystems upon which the welfare of humans depends. In the years leading to passage of the MMPA, only one issue- the Vietnam War-generated more mail from the public to members of the U.S. Congress.

Three issues were of particular concern to Congress, the scientific community, and the public at the time the MMPA was being formulated:

• the killing of hundreds of thousands of dolphins each year in the eastern tropical Pacific Ocean as a result of setting purse seines around dolphin schools to catch yellowfin tuna that associate with the dolphins;
• the failure of the International Whaling Commission (IWC) to prevent the overexploitation and near-extinction of virtually all stocks of large whales throughout the world; and
• the clubbing and skinning of tens of thousands of newborn (baby) harp seals each year in the ice fields of the North Atlantic for the international fur market.

Since passage of the Act, a broad spectrum of additional issues has surfaced. These include declines of additional species and stocks in both U.S. and international waters. Examples include West Indian manatees, West African manatees, California sea otters, Alaska sea otters, Steller sea lions, Hawaiian monk seals, Mediterranean monk seals, killer whales (orcas), the Gulf of California harbor porpoise (vaquita), and the Chinese and Amazon River dolphins. Other issues include unintentional taking incidental to offshore oil and gas development and a variety of commercial fisheries; the taking of bowhead whales and other marine mammals by Alaska Natives for subsistence and handicraft purposes; increases in some populations of harbor seals and California sea lions and corresponding calls by fishermen and fisheries groups to cull the populations to limit their predation on commercially valuable fish stocks; unusual mortality events such as the massive die-off of bottlenose dolphins that occurred along the U.S. mid-Atlantic coast in 1987 and 1988; and increasing threats associated with point and non-point sources of ocean pollution, lost and discarded fishing gear and other types of persistent marine debris, ship strikes, human sources of ocean noise, and ecosystem changes due to climate disruption and global warming.

(top)

Key provisions of the MMPA

In formulating the MMPA, the lawmakers determined that

• certain species and population stocks of marine mammals were in danger of extinction and depletion as a result of human activities;
• such species and stocks should not be permitted to diminish below the level at which they cease to be significant functioning elements in the ecosystems of which they are a part and, consistent with this principal objective, should not be permitted to diminish below their optimum sustainable population level; and
• marine mammal species and population stocks should be encouraged to develop to the greatest extent feasible consistent with sound policies of resource management, with the primary objective of their management being to maintain the health and stability of the marine ecosystem.

The MMPA is unique in several respects:

• It is the first legislation anywhere in the world to mandate an ecosystem approach to the conservation of marine living resources.
• It establishes the concept of "optimum sustainable populations" (OSP).
• It is the first U.S. legislation to shift the burden from resource managers to resource users to show that proposed taking of marine living resources would not adversely affect the resources or the ecosystems of which they are a part (i.e., it prohibited the hunting, killing, capture, or harassment of marine mammals for other than scientific research, public display, or subsistence uses by Alaska Natives unless the advocate of the activity could provide reasonable evidence that the activity would not cause the affected species or stock to be reduced below its optimum sustainable level).
• It directs the relevant federal agencies to seek corresponding changes in international agreements such as the Whaling Convention and the North Pacific Fur Seal Convention.
• It established an independent overview body and scientific advisory group - the Marine Mammal Commission and its Committee of Scientific Advisors - to oversee implementation of the Act and to advise Congress and the responsible regulatory agencies of needed actions.

(top)

A new perspective

Before enactment of the MMPA, individual states were responsible for conserving and regulating the take of marine mammals in their adjacent coastal waters. The Department of State was responsible for conserving and regulating the take of marine mammals on the high seas through international agreements such as the International Whaling Convention and the North Pacific Fur Seal Convention. Many marine mammals, such as the great whales, were viewed as commodities, like fish and shellfish, and were managed to obtain maximum sustainable yields, an outdated single-species management concept. Others, such as harbor seals and California sea lions, were viewed as vermin, competing with fishermen for fish and shellfish resources, and were the subject of bounty programs and unrestricted hunting.

The MMPA established a moratorium on the taking of marine mammals in U.S. waters and the importation of marine mammals and derived products into the United States. It assigned responsibility for whales, dolphins, porpoises, seals, and sea lions to the Department of Commerce, which in turn assigned most of those responsibilities to the National Marine Fisheries Service (NMFS). Responsibility for walruses, polar bears, manatees, dugongs, and sea and marine otters was assigned to the Department of the Interior, which in turn assigned most of its responsibilities to the Fish and Wildlife Service (FWS). The Secretary of State was directed to seek new international agreements and the amendment of existing agreements to further the purposes and polices of the Act.

Congress recognized that there were legitimate uses of marine mammals and marine mammal products and that states such as Alaska had vested interests in controlling the taking of marine mammals in their coastal waters and land areas. Consequently, the MMPA includes provisions for both waiving the moratorium on taking and returning management authority to states. Likewise, it recognizes the importance of marine mammal research and public education, and provides for permits to be issued by the responsible regulatory agencies - NMFS and FWS-authorizing the taking of marine mammals and importation of marine mammals and marine mammal products for scientific research and public display. It also recognizes that marine mammals often are caught unintentionally in commercial fisheries and provides that permits be issued to authorize such taking if it would not "disadvantage" the affected species or stocks. Further, the Act recognizes that many Alaska Natives residing along the coast are dependent on marine mammals for food and other subsistence needs. It therefore exempts from the moratorium the hunting of marine mammals by Alaska Natives for subsistence and handicraft purposes, provided that taking does not threaten the continued existence of the affected species and stocks.

(top)

Interactions between marine mammals and commercial fisheries

Dolphins and the eastern tropical Pacific tuna purse seine fishery: The deaths of hundreds of thousands of dolphins each year in the eastern tropical Pacific Ocean as a consequence of setting purse seines around dolphin schools to catch yellowfin tuna was one of the issues that led to enactment of the MMPA. Early attempts by NMFS to authorize the encirclement and associated mortality of unspecified numbers of dolphins in the eastern tropical Pacific led to lawsuits asserting that NMFS had not established a limit on the number of dolphins that could be encircled and killed and had not determined the size or status of the affected dolphin stocks relative to their OSP levels. The court subsequently determined that NMFS had violated the MMPA.

In partial response to that order, NMFS convened a group of experts, including the Chairman of the Marine Mammal Commission, to review available information and provide assessments of the sizes and OSP status of the affected dolphin stocks. They concluded that the three stocks most affected by the fishery - the offshore stock of spotted dolphins and the eastern tropical Pacific stocks of eastern spinner and white-belly spinner dolphins were approximately 64 percent, 54 percent, and 76 percent, respectively, of their pre-fishery or pre-exploitation sizes. A quantitative measure of OSP had yet to be defined, and the workshop participants adopted 60 percent of the estimated carrying capacity level as the lower limit of the OSP range, in the absence of information to the contrary. They therefore concluded that the eastern spinner stock was below and the offshore spotted stock was approaching the lower limit of their OSP range.

Details of these and other actions regarding the "tuna-dolphin" problem can be found in the annual reports of the Marine Mammal Commission, NMFS, and the Inter-American Tropical Tuna Commission. As indicated there, the number of dolphins killed annually in the eastern tropical Pacific tuna purse seine fishery has declined from more than 400,000 in 1972 when the MMPA was enacted to fewer than 5,000 since the early 1990s. However, it appears that the depleted stocks of spotted and spinner dolphins have not recovered, due possibly to unobserved or unreported mortality and/or stress caused by chase and capture.

Interactions with U.S. commercial fisheries: In May 1987 NMFS issued a permit to the Japanese Salmon Fisheries Cooperative Association authorizing the take of up to 2,942 Dall's porpoises annually, for a period of three years, incidental to salmon driftnet fishing in the U.S. 200-mile Fishery Conservation Zone off Alaska. Shortly after the permit was issued, several Native Alaskan fishing groups and environmental organizations filed suit claiming, among other things, that the permit violated the MMPA because it applied only to Dall's porpoises when it was virtually certain that other marine mammals would also be taken, including northern fur seals from the depleted populations on St. Paul and St. George Islands. The court ruled in favor of the plaintiffs and issued a preliminary injunction voiding the permit - a ruling upheld after appeal by NMFS.

Both the environmental community and the fishing industry, as well as the state and federal regulatory agencies, recognized that a total prohibition on the incidental taking of marine mammals would have a severe economic impact on a number of U.S. fisheries. In addition, it was clear that available information was insufficient in most cases to reliably assess and determine how to avoid or mitigate the adverse effects of interactions on the affected marine mammals and fisheries. Consequently, Congress amended the MMPA in 1988 to provide a five-year exemption to the Act’s permit and "small-take" requirements for U.S. and certain foreign fisheries other than the eastern tropical Pacific tuna purse seine fishery covered by other provisions of the Act. The basic purposes of the five-year exemption were to provide time to (1) compile and analyze data on the types, levels, and biological and socioeconomic implications of marine mammal/fishery interactions in U.S. waters, and (2) develop a new regime to govern interactions that both avoids adverse effects on marine mammals and minimizes the impact on fisheries.

The amendments themselves and the subsequent efforts by the Commission and NMFS to implement them resulted in several practical and philosophical changes to the regulation of marine mammal/fishery interactions. For example, the incidental take of marine mammals listed as endangered or threatened under the Endangered Species Act or depleted under the MMPA could be authorized if the taking would not cause a further decline or impede recovery of the affected species or stocks. The amendments also recognized that placement of sufficient numbers of trained observers aboard fishing vessels is necessary to obtain reliable information on fishing practices and on catches of both target and non-target species. The amendments also placed much of the marine mammal decision-making and funding authority in NMFS’ Office of Protected Resources at its headquarters in Silver Spring, Maryland. Among other things, this minimized regional differences in perceptions of and efforts to deal with marine mammal research and management problems. Finally, the new regulatory regime proposed to Congress by NMFS in December 1992 suggested a new and simpler conceptual means for assuring that incidental take in commercial fisheries does not cause any marine mammal species or stock to be reduced or to be maintained below the lower limit of its OSP range as described earlier. That concept, calculation of potential biological removal (PBR) levels, was incorporated in the 1994 amendments to the MMPA.

A new regime for governing incidental takes: In 1994, Congress enacted several significant changes to the MMPA’s provisions regarding marine mammal/ fishery interactions. Those changes were intended to regulate the taking of marine mammals incidental to commercial fisheries in U.S. waters and to minimize the impact of the regulations on the affected fisheries. The amendments reflected input from the fishing industry and the environmental community as well as from the Commission, NMFS, and FWS.

In summary, the 1994 amendments directed NMFS to

• prepare and periodically update status reports for all marine mammal stocks in U.S. waters;
• estimate the potential biological removal level for each stock (defined as the maximum number of animals, not including natural mortalities, that may be removed from a stock while allowing that stock to reach or maintain its optimum sustainable population);
• identify which marine mammal stocks are considered strategic (defined as having a level of human-caused direct mortality that exceeds the stock’s potential biological removal, or which is listed or likely to be listed as threatened or endangered under the Endangered Species Act or depleted under the MMPA);
• establish regional scientific review groups to advise NMFS on the preparation and revision of stock assessments;
• continue the vessel registration and observer programs established in accordance with the 1988 amendments;
• develop take reduction plans for each strategic stock that interacts with a Category I or Category II fishery (fisheries that, respectively, frequently or occasionally kill or seriously injure marine mammals);
• establish take reduction teams, composed of scientists and representatives of the various fishery and environmental interest groups, to draft the take reduction plans.

Details of the amendments are described in the Marine Mammal Commission's report to Congress for calendar year 1994. Current and past stock assessment reports and information regarding take reduction teams and plans can be obtained on NMFS’ Office of Protected Resources web site.

Although not without some controversy, the system established by the 1994 MMPA amendments to govern marine mammal/fishery interactions has worked effectively to both regulate the taking of marine mammals incidental to commercial fisheries in U.S. waters and to minimize the impact of the regulations on the affected fisheries.

(top)

Strandings and unusual mortality events

Marine mammals that strand alive or wash ashore dead provide important sources of information on the distribution, regional abundance, anatomy, physiology, general condition, and diseases of marine mammals. Under the authority of the MMPA, regional networks of volunteers respond to and collect data on both live and dead marine mammal strandings. These volunteer networks have produced a large database on the species, numbers, general condition, and causes of marine mammal strandings in the United States. They also have served as a model for establishing stranding response programs in other parts of the world. The volunteer networks have been instrumental in detecting and investigating the increasing numbers of unusual mortality events, or "die-offs," worldwide.

Because of the difficulties encountered in responding to and uncertainties concerning the cause of marine mammal die-offs, such as the die-off that occurred along the mid-Atlantic coast in 1987-1989, Congress in 1992 enacted the Marine Mammal Health and Stranding Response Act as Title IV of the MMPA. Among other things, this legislation directed NMFS to

• establish an expert working group to provide advice on measures necessary to better detect and respond to unusual mortality events;
• develop a contingency plan to help ensure prompt and effective response to unusual mortality events;
• establish a fund to compensate individuals and organizations for certain costs incurred in responding to unusual events;
• develop objective criteria for determining when rehabilitated, live-stranded marine mammals can be returned to the wild;
• continue development of the National Marine Mammal Tissue Bank at the National Institute of Standards and Technology; and
• establish and maintain a central database for tracking and accessing data concerning marine mammal strandings.

In response to this directive, NMFS, among other things, has constituted and staffed the expert advisory group and has developed a National Contingency Plan for Response to Unusual Marine Mammal Mortality Events. Funding of the regional stranding networks has been a problem and, in December 2000, Congress enacted the Marine Mammal Rescue Assistance Act directing NMFS and FWS to initiate grant programs to improve the effectiveness of the stranding networks. The grants are intended to provide financial assistance for recovery and treatment of live-stranded animals, collection and archiving of data from both live - and dead-stranded animals, and the operational costs directly related to those activities. Grants may be awarded for up to three years with a cumulative total of $100,000 per eligible participant per year.

(top)

Contaminants, noise, and other environmental threats

As noted earlier, a number of threats to marine mammals and other marine biota were not apparent or widely recognized when the MMPA was enacted in 1972. These include entanglement in lost and discarded fishing gear and other types of marine debris; disturbance and possible injury and mortality associated with loud sounds from human sources; introduction of increasing amounts and varieties of fertilizers, pesticides, herbicides, pharmaceuticals, and other chemical contaminants into the world’s oceans; and climate disruption by greenhouse gas emissions.

Marine debris pollution: The marine debris problem is largely a product of the development and use of persistent, non-biologically degradable plastics and other synthetic materials for the manufacture of fishing nets and lines, and packaging materials such as garbage bags and soda and beer six-pack holders. It was first recognized as a potentially significant marine conservation problem in the late 1970s and early 1980s when northern fur seal and Hawaiian monk seal populations were found to be declining coincident with observations of increasing numbers of animals in pupping colonies entangled in bits of fishing net and line and other types of marine debris. Unknown but potentially significant numbers of sea turtles, seabirds, and fishes, as well as marine mammals, mistake floating plastic bags, deflated balloons, bits of styrofoam, and other synthetic materials for food items and die because the items are indigestible and either clog their digestive tracts or poison them. Additional information on efforts to quantify, characterize, and reduce interactions between marine mammals and debris can be found on the NOAA Marine Debris Program website or at the Ocean Conservancy’s website. Both have played a significant role in calling attention to the problem of marine debris and enlisting the public in efforts to resolve it.

Ocean noise pollution: Human activities are increasing the level of sound in the oceans, causing widespread concern about potential effects on marine mammals and marine ecosystems. Major human sources of sound include seismic surveys for oil and gas exploration and scientific research; commercial shipping for transportation of goods; and sonar systems for military purposes, fishing, and research. Sound also is important to marine mammals for communication, individual recognition, predator avoidance, prey capture, orientation, navigation, mate selection, and mother-offspring bonding. Potential effects of anthropogenic sounds on marine mammals include physical injury, physiological dysfunction (for example, temporary or permanent loss of hearing sensitivity), behavioral modification (for example, changes in foraging or habitat-use patterns, separation of mother-calf pairs), and masking (that is, inability to detect important sounds due to increased background noise). For individual animals, such effects and their secondary consequences may vary in significance from negligible to fatal-the worst outcome being documented in a small number of cases. The implications for conservation of marine mammal populations are undetermined.

The first indications that human sources of ocean sound might be a problem surfaced in the late 1970s and early 1980s when studies in Alaska and Canada found that the distributions, movements, and behavior patterns of ringed seals, beluga whales, and bowhead whales were affected by sounds associated with offshore oil and gas exploration, sometimes at distances in excess of 10 kilometers (km). The effects on marine mammal behavior found in early studies were thought to be biologically insignificant. Consequently, section 101(a)(5)(A) was added to the MMPA in 1981 directing the Secretaries of Commerce and the Interior to authorize, for periods up to five years, the unintentional taking, including the accidental killing, of small numbers of non-depleted marine mammals incidental to activities other than commercial fisheries. If the taking involved only small numbers of marine mammals, the impacts on the affected species and stocks would be negligible, and the responsible regulatory agency (NMFS or FWS) would issue regulations specifying when, where, what, why, and how many marine mammals were authorized to be taken. This provision was amended in 1986 to authorize the unintentional taking of small numbers of depleted as well as non-depleted marine mammal species (for example, endangered bowhead whales when the population-level effects would be negligible and there would be no unmitigable effects on the availability of the affected species or stocks for taking by Alaska Natives for subsistence purposes).

Although the effects of offshore oil and gas development have continued to be the subject of controversy and study, much of the concern and controversy in the past 15 years has been focused on activities conducted or supported by the U.S. Navy. Because of the concern and controversy concerning the possible effects of anthropogenic sound on marine mammals, the National Research Council has conducted four separate studies to assess, identify uncertainties, and suggest means for addressing the problem (National Research Council 1994, 2000, 2003, 2005). Also, Congress in the Omnibus Appropriations Act of 2003 (Public Law 108-7) directed the Marine Mammal Commission to "fund an international conference or series of conferences to share findings, survey acoustic 'threats' to marine mammals, and develop means of reducing those threats while maintaining the oceans as a global highway of international commerce." The Commission convened an Advisory Committee on Acoustic Impacts on Marine Mammals and sponsored a series of meetings and workshops to gather information necessary to carry out the directive. The Commission, in consultation with the Advisory Committee, determined that a national approach to the sound issue was needed, and should include an expanded research program to improve our understanding and a more effective, comprehensive management approach to ensure marine mammal conservation while minimizing unnecessary constraints on sound-producing activities.

Chemical pollution: The greatest long-term threats to marine mammals, sea turtles, fish, seabirds, and other marine organisms may well be non-point-source ocean contamination (i.e., herbicides, pesticides, fertilizers, road tars, pharmaceuticals, etc. that are carried by rain runoff and sewage into rivers and ultimately into the world’s oceans). Such contaminants have been found in the tissues of marine mammals and other marine organisms from the Arctic to the Antarctic and virtually everywhere in between. Although there is a growing database concerning the types and levels of contaminants present in the tissues of marine mammals and other marine organisms in many areas, very little is known about the effects of the contaminants, either singularly or collectively, on the growth, longevity, or reproduction of the affected biota. To date, there has been only limited progress in documenting the sources and effects of various contaminants and how introduction of harmful contaminants into the world’s oceans can be minimized. These clearly are topics meriting more attention.

(top)

Looking forward

Since the MMPA was enacted in 1972, there has been substantial progress in addressing a number of marine mammal and marine ecosystem conservation issues. However, several issues have resisted solution, and a number of new or previously unrecognized, and sometimes controversial, issues have arisen. These include the escalating controversy concerning the effects of anthropogenic sound on marine mammals and other marine organisms, the cumulative effect of sound and other stressors on marine mammal populations, and uncertainty concerning the direct and indirect effects on marine mammals of climate change. Unfortunately, litigation often dictates agency priorities and responses to living resource conservation issues here in the United States and in some other countries. This is a consequence of competing interests and values regarding resource use and promotes the inevitable cycle of ineffective and costly crisis management.

Failure to anticipate resource conservation issues well in advance leads almost inevitably to (a) overutilization and depletion of the resource or uncertainty concerning the effects of ongoing activities; (b) the need to restrict or limit the activity in question to enable recovery of the resource or to resolve the uncertainty concerning its possible adverse effects; (c) actual or perceived socioeconomic impacts if the activity is prohibited or restricted; (d) lobbying of Congress and the responsible regulatory agency, and the threat of litigation due to competing and polarized views as to the appropriate course of action; (e) delayed or no action by the responsible regulatory agency leading to further depletion of the resource and/or escalation of the controversy concerning the necessary conservation measures; (f) utilization of limited agency financial and personnel resources to avoid or respond to lobbying and lawsuits, reducing the funding and personnel available for dealing with the actual problem; and (g) often ineffective solutions as a consequence of attempting to satisfy or seek a balance between conflicting interests.

The future of marine mammal conservation depends on the willingness and ability of governments, government agencies, international organizations, affected industries, and public interest groups to work together to anticipate and find solutions to conservation problems that are both biologically and economically sound.

*This chapter is based on a review of past issues in marine mammal conservation written by John R. Twiss Jr., the Executive Director of the Marine Mammal Commission from 1975 to 2000; Robert J. Hofman, the Commission's Scientific Program Director from 1976 to 2000; and John E. Reynolds III, past member and Chairman of the Commission's Committee of Scientific Advisors on Marine Mammals and Chairman of the Commission from 1991 to the present. The review is included in the volume Foundations of Environmental Sustainability: The Co-Evolution of Science and Policy, published by Oxford University Press in 2007. The Commission gratefully acknowledges Oxford University Press for its kind permission to use portions of that work.

(top)