Legislative Mandates of the Endangered Species Act and a Plea for Consistent Use of Technical Terms

By: Jay O'Laughlin


The Endangered Species Act (ESA) is a public policy for protecting, and improving the status of, plants and animals whose continued existence is imperiled. ESA policy consists of a legislative statute, administrative regulations and guidelines, and judicial rulings. The ESA statute includes hortatory declarations such as the purpose of the Act (ESA § 2), definitions (ESA § 3), and mandates for executive agencies. These mandates include interagency cooperation (ESA § 7) and substantive outcomes, such as a list of protected species and their recovery plans (ESA § 4) and protection against take (ESA § 9). (See Sidebar for definitions of underlined terms.)

Understanding the goals of the ESA statute and the Act's implementation mechanisms can enhance species conservation programs by improving communication among interested parties. Describing ESA ends and means with consistent and precise use of ESA-defined terms facilitates discussion of and improvements to implementation issues.

An Endangered Species UPDATE article by a U.S. Fish and Wildlife Service (FWS) official (Clark 1996) reviewing the ESA's legislative mandates did only a partial job, in my opinion. Personal or agency viewpoints sometimes obscured the underlying statutory requirements and several terms were misused. For example, by stating that the ESA is a "clear public policy...to prevent the destruction of nature's diversity," Clark (1996) was offering an interpretation of ESA policy, not describing a legislative mandate. "Diversity" is a term absent from the ESA, however, "destruction" is used in section 7 in reference to critical habitat. The ESA's imperfect blend of biological science and law (Rohlf 1991) makes understanding its mandates anything but clear.

The ESA's mandates can be explained by analyzing the three key parts of the statutory design­identification, protection, and recovery (O'Laughlin and Cook 1995). First, Clark (1996) clearly explained identification, which is the section 4 process for listing threatened or endangered species. Second, she described protection as the "primary objective" of the ESA program (Clark 1996). However, she inexplicably omitted section 7 jeopardy and critical habitat protections, while section 9 take protection was adequately explained. Third, although Clark considers recovery to be the "ultimate purpose" of the Act (Clark 1996), she substituted some interpretations for mandates. For example, Clark said the FWS oversees recovery activities, but failed to mention that section 4(f) mandates the FWS to develop and implement recovery plans. Finally, although they are not mandates, Clark (1996) also described how responsibilities for marine animals are split between agenciesÑthese assignments have far-reaching implications deserving more discussion than was provided.

This article complements Clark's article on southern sea otter (Enhydra lutris nereis) conservation by focusing on section 7 protection, recovery mandates, and agency responsibilities. I use ESA-defined technical terms (see Sidebar), and separate legislative mandates from agency viewpoints, administrative regulations, judicial interpretations, and court rulings.

Section 7 protection

The statute mandates that federal agencies neither jeopardize listed species nor adversely modify their critical habitat. In her brief discussion of section 7, Clark (1996) failed to mention the two protection provisions of the ESA's "Interagency Cooperation": jeopardy protection and habitat protection.

Jeopardy protection

Clark stated that the Interior Secretary, acting through the FWS, "oversees the protection and conservation of fish, wildlife, and plants found to be in serious jeopardy" (Clark 1996). This use of jeopardy adds confusion and vagueness by inconsistently using a technical term. "Seriously imperiled" would have been a more appropriate phrase, especially when Clark used "imperiled" in a similar context in her concluding paragraph. Absent from the ESA statute or regulations, "imperiled" is convenient for avoiding repetitive use of "threatened and endangered."

Jeopardy is a vague standard used for protecting listed species. Section 7 provides statutory protection by mandating that any action by a federal agency may not jeopardize the continued existence of a listed species. Through the consultation process defined in section 7, the FWS or the NMFS must provide a written statement, called a biological opinion, if a federal action may jeopardize a species. "Jeopardize" is not defined in the ESA statute, but is in FWS regulations (see Sidebar). There are no degrees of jeopardy in the ESA.

Habitat protection

Discussion herein separates ESA statutory requirements for protecting habitat for imperiled species from implementation of the Act by the FWS. This analysis should not be construed as an attempt to diminish the crucial importance of habitat protection in many species conservation programs.

According to Clark (1996) "the ESA is habitat-oriented. It seeks to conserve 'the ecosystems upon which endangered species and threatened species depend.'" This interpretation is inconsistent with mandates and statutory design. One of the purposes of the ESA is to "provide a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved" (ESA § 2(b)). The means to this end is the listing of individual species (NRC 1995).

The ESA statute is species-oriented. To say otherwise, one would have to argue that protection of critical habitat is the same as ecosystem conservation. The critical habitat approach can effectively protect ecosystems only if it is pursued rigorously (NRC 1995). The FWS does not do so; less than 15% of the listed species have designated critical habitat.

Furthermore, the ESA definition of conserve (see Sidebar) applies to species, not their habitat, and conservation involves actions to promote species recovery. Such actions may or may not include habitat protection, depending on the role of habitat as one of five factors considered in listing determinations. The other factors considered are overutilization, disease or predation, regulatory inadequacy, and other impacts on continued existence (ESA § 4(a)). Actions benefiting a listed species would generally benefit an ecosystem in which the species is a component, however, other parts of the same ecosystem may be adversely affected by managing for listed species. For example, southern sea otter conservation efforts negatively affect fisheries and abalone (Wendell 1996) and sea urchin populations, with largely unknown ecological effects on kelp forests and associated coastal organisms (VanBlaricom 1996).

Congress intended that the ESA would protect habitat through the critical habitat feature, however, the FWS prefers to use its discretionary authority to protect habitat in a way not envisioned by Congress (Houck 1993). Using the harm definition, the FWS protects habitat for listed species regardless of whether or not it is critical; i.e., essential for conservation (see Sidebar). The regulatory definition of harmÑa component of the statutory definition of take (see Sidebar)Ñrenders critical habitat meaningless (Bean 1983). In 1995, the controversial definition of harm was upheld by the Supreme Court (Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, 115 S.Ct. 2407, 1995).

Critical habitat has not been designated for the southern sea otter, as is the case with more than 85% of listed species. By ignoring the term "critical habitat" and stating that federal agencies must protect "important habitat," Clark (1996) avoided the contentious issues associated with critical habitat. For example, the FWS is required to designate critical habitat under section 4 and protect it from destruction or adverse modification under section 7 except when it is imprudent or undeterminable (50 C.F.R. § 424.12(a)). In addition, critical habitat designation is a legislative mandate enforceable through judicial review, as in Northern Spotted Owl v. Lujan (758 F. Supp. 621, W.D. Wash. 1991). Critical habitat issues have been analyzed elsewhere (see Tobin 1990, Murphy and Noon 1991, Houck 1993, O'Laughlin and Cook 1995).


Recovery is the "ultimate purpose" of the ESA program (Clark 1996). By identifying the responsibilities of the regulatory agencies as "overseeing recovery activities for listed species," Clark (1996) may have understated their role, depending on what "overseeing" might mean. Section 4(f) mandates that the "...Secretary shall develop and implement [recovery] plans for the conservation and survival of [listed] species." This mandate is a more compelling directive than "overseeing recovery activities."

Clark (1996) mentioned the southern sea otter translocation law (Publ. Law 99-625) as requiring the FWS to develop and implement a recovery plan, but neglected to say that section 4(f) mandates that a recovery plan provide "objective, measurable criteria...that the species be removed from the list," as well as "estimates of the time required and the cost to carry out those measures needed to achieve the plan's goal." The agencies implementing the ESA are thus mandated to plan and implement activities that will result in the recovery and subsequent de-listing of the species.

Agency responsibilities

Almost all ESA implementation tasks are assigned to the Secretaries of the Interior and Commerce Departments (ESA § 3(15)). Nevertheless, all federal agencies have an affirmative duty to conserve species (ESA § 7).

Agency assignments for marine animals do not follow any prescribed protocol. Interior, through the FWS, is responsible for manatees, walruses, sea otters, and polar bears; whereas Commerce, through the National Marine Fisheries Service (NMFS), is responsible for seals, whales, dolphins, porpoises, and sea lions. These assignments were made following the creation of the NMFS in 1970 and had nothing to do with protecting endangered species; instead they reflect the agencies' interests, abilities, preferences and a spirit of compromise (Tobin 1990).

The FWS generally argues that the agency should have some responsibility for all species at risk of extinction. For example, following the ESA's enactment in 1973, the FWS and NMFS resolved a jurisdictional dispute over sea turtles: the NMFS has jurisdiction when turtles are at sea, the FWS when turtles come on land to lay their eggs.

Either the FWS did not vie for responsibility or the agency's efforts carried little weight when the first population of anadromous fish, the winter-run Sacramento River chinook salmon (Oncorhynchus tshawytscha), was listed in 1990. Soon after, three salmon populations native to Idaho's Snake River and its tributaries were also listed. The NMFS has jurisdiction for salmon throughout their life cycle, including when the fish move from the ocean into fresh water to spawn in their natal streams and rivers. This brings the NMFS into Idaho, hundreds of miles from the marine environment, where the agency is responsible for recommending changes in activities on or near federal land that may affect freshwater ecosystems, including grazing, logging, mining, and recreation.


The ESA raises fascinating economic, institutional, and political issues that will not soon fade (Tobin 1990). Because of the controversies associated with these issues, we should use language to precisely and clearly separate facts from values. Legislative mandates are matters of fact and deserve to be presented as such. Even though the statute is only one part of ESA policy, it is a good starting point for understanding policy implementation. Vague definitions aside, the ESA is a clear statement of a national commitment to protect imperiled plants and animals and improve their situation. Personal values and agency interpretations masquerading as fact muddy up, rather than clarify, our understanding of implementation issues and inhibit debate about socially acceptable means to attain the ESA goal.


J. Michael Scott and Philip S. Cook provided helpful comments on the draft manuscript. This is Contribution no. 837 of the University of Idaho's Forest, Wildlife and Range Experiment Station.

Literature cited

Bean, M. J. 1983. The evolution of national wildlife law. Praeger, New York.

Clark, J. R. 1996. Overview of the legislative mandates and the agencies responsible for implementation of southern sea otter protection under the Endangered Species Act. Endangered Species UPDATE 13(12):28-30.

Houck, O. A. 1993. The Endangered Species Act and its implementation by the U.S. Departments of Interior and Commerce. University of Colorado Law Review 64(2):277-370.

Murphy, D. D. and B. R. Noon. 1991. Opinion­exorcising ambiguity from the Endangered Species Act: critical habitat as an example. Endangered Species UPDATE 8(12):6.

National Research Council (NRC). 1995. Science and the Endangered Species Act. National Academy Press, Washington, D.C.

O'Laughlin, J. and P. S. Cook. 1995. Endangered Species Act at the crossroads: new directions from Idaho case studies. Idaho Forest, Wildlife and Range Policy Analysis Group Report 13, University of Idaho, Moscow. (Executive summary available separately.)

Rohlf, D. J. 1991. Six biological reasons why the Endangered Species Act doesn't work­and what to do about it. Conservation Biology 5(3):273-282.

Tobin, R. J. 1990. The expendable future: U.S. politics and the protection of biological diversity. Duke University Press, Durham, NC.

VanBlaricom, G. R. 1996. Saving the sea otter population in California: contemporary problems and future pitfalls. Endangered Species UPDATE 13(12):85-91.

Wendell, F. 1996. The State of California's role in the conservation of sea otters and other aquatic resources. Endangered Species UPDATE 13(12):82-84.

Jay O'Laughlin is Director, Idaho Forest, Wildlife and Range Policy Analysis Group (PAG), and Professor, Department of Forest Resources, University of Idaho, Moscow, ID. The PAG was created by the Idaho legislature in 1989 as a research unit of the University of Idaho's College of Forestry, Wildlife and Range Sciences, with a legislative mandate to provide objective data and analysis of natural resource issues of interest to the citizens of Idaho.

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