Federal Wildlife Agencies Propose Rescinding Definition of “Harm” Under Endangered Species Act
On April 17, 2025, the U.S. Fish and Wildlife Service and National Marine Fisheries Service (Services) proposed a rule to rescind the regulatory definition of “harm” under the Endangered Species Act (ESA). The proposed rule is open for public comment through May 19, 2025.
If the proposal results in the issuance of a final rule, impacts to listed species’ habitat alone may no longer trigger the requirement to receive a federal ESA permit before proceeding with a project. The outcome of the proposed rule could have implications for some types of water operations and a variety of public infrastructure projects because these activities often require “take” authorization from the Services for impacts to habitat, even in cases where listed species may not be present.
Background
Section 9 of the ESA and federal regulations prohibit the taking of listed endangered and threatened species without federal authorization. The statute defines “take” as to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture or collect or attempt to engage in any of this conduct. By regulation, and for the past 50 years, the Services have defined “harm” to include habitat modification or degradation that results in death or injury to endangered or threatened species by impairing essential behavioral patterns.
The proposed rule states that the existing definition of harm—which includes habitat modification or degradation—runs contrary to the best meaning of the statutory term “take.” According to the Services, the definition of “harm” requires rescission to adhere to the “single, best meaning of the ESA.”
The proposed rule does not offer an alternative definition of “harm” to replace the existing one. Instead, it cites Justice Scalia’s dissent in Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, 515 U.S. 687 (1995) and states that no replacement is needed because “take” is already defined in the ESA. The Services reason that further elaborating on one component of that definition (i.e., “harm”) is unnecessary in light of the comprehensive statutory definition of “take.”
Practical implications
If finalized, this regulation may have implications for ongoing water operations and a variety of public infrastructure projects including renewable energy, telecommunications, transportation, water, and waste management, among others.
“Harm” via incidental habitat modification or degradation is the most prevalent form of “take” regulated by the Services. Any state or local agency proposing an action that is anticipated to result in “harm” to a threatened or endangered species—such as constructing an infrastructure project or operating a water project affecting listed species—is required to apply for incidental take authorization under the ESA. This authorization ordinarily comes in the form of an incidental take permit issued under Section 10 of the ESA in conjunction with approval of a habitat conservation plan, or by way of an incidental take statement provided under a biological opinion issued under Section 7.
The regulation, if finalized, would likely narrow the scope of actions—including public infrastructure projects and water operations—that are subject to permitting and consultation requirements under the ESA. The outcome of this proposed rule could be consequential for state and local agencies with ongoing or future projects involving lands with listed species concerns, particularly if the land contains habitat but species do not actually occupy the site.
The meaning of “harm”
Congress passed the ESA in 1973 (87 Stat. 884) to conserve species listed by the Secretary of the Interior as endangered or threatened. The aforementioned regulation that defines “harm”—and includes incidental habitat modification or degradation—has been in place since 1975. In Sweet Home, the Supreme Court upheld this regulatory definition of “harm” based on Chevron U.S.A. Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984), which required deference to a federal agency’s interpretation of a statute in cases where the law is ambiguous and the agency’s interpretation is reasonable. The Court in Sweet Home reasoned that it need not determine whether the definition of “take” compelled an interpretation of “harm” to include incidental habitat modification or degradation. Rather, because the law was ambiguous and the interpretation was reasonable, the Court upheld the regulatory definition of “harm.”
Fast forward to the recent decision in Loper Bright Enterprises v. Raimondo, 603 U.S. 469 (2024), which overturned longstanding deference to agency interpretation under Chevron. The Court in Loper Bright ruled that the Administrative Procedure Act requires courts to exercise independent judgment in deciding whether an agency has acted within its statutory authority. In the proposed rule, the Services invoke the holding in Loper Bright to determine that the definition of “harm” upheld in Sweet Home does not match the “single, best meaning of the statute [i.e. the ESA].”
However, the Court in Loper Bright also made clear that prior cases relying on Chevron—say, for instance, the decision in Sweet Home upholding the definition of “harm” —are not called into question and are still valid law under the legal doctrine of stare decisis, which is akin to respecting prior decisions. The Services address this issue directly in the proposed rule. They maintain that rescission of the regulatory definition of “harm” does not run afoul of the stare decisis direction in Loper Bright because the decision in Sweet Home held only that the existing regulation was a permissible reading of the ESA, not the only possible reading.
How BBK can help
Best, Best & Krieger LLP (BBK) attorneys will continue to monitor developments of the proposed rule as well as the legal and policy implications of this dynamic situation. For questions about how the regulation may impact an ongoing or proposed public infrastructure project, please contact Steve Anderson and Gary Gold.
Best, Best & Krieger can assist if your agency or city is interested in submitting comments.
Disclaimer: BBK Legal Alerts are not intended as legal advice. Additional facts, facts specific to your situation, or future developments may affect subjects contained herein. Seek the advice of an attorney before acting or relying upon any information herein.
