CSG Law Environmental Blog: Federal Rollback of ESA “Harm” Definition Could Reshape Federal Project Permitting
The U.S. Fish and Wildlife Service and National Marine Fisheries Service have rescinded the regulatory definition of “harm” under the Endangered Species Act, 16 U.S.C. § 1532, (“ESA”), removing the longstanding position that significant habitat modification or degradation can constitute prohibited harm to listed species. The word “harm” remains listed in the ESA as a component of the prohibition against taking endangered species. However, effective on September 14, 2026, the agencies have removed the specific regulatory definition for “harm” from the Code of Federal Regulations. The agencies’ revised approach focuses on direct injury to individual animals or plants, rather than indirect impacts resulting from habitat destruction. Because habitat preservation has historically been a central mechanism for protecting threatened and endangered species, the change has the potential to reduce regulatory constraints on development, infrastructure, energy, forestry, and agricultural projects affecting occupied habitat. The new interpretation conflicts with the 1995 U.S. Supreme Court decision in Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, 515 U.S. 687, but conforms with Justice Scalia’s dissenting opinion in that case.
A coalition of environmental organizations has filed lawsuits in federal courts challenging the rulemaking. The plaintiffs contend that the agencies’ action conflicts with decades of ESA implementation and judicial precedent recognizing that habitat destruction can effectively injure or kill species by impairing breeding, feeding, sheltering, and other essential life functions. The lawsuits also allege that the agencies failed to comply with requirements under the Administrative Procedure Act and the National Environmental Policy Act when adopting the revised interpretation.
The litigation presents a significant question regarding the future scope of federal endangered-species protections. If the challengers prevail, courts could restore the broader interpretation of “harm,” preserving habitat-based protections that have long been applied in ESA enforcement and permitting decisions. If the rescission of the regulatory interpretation is upheld, project proponents may face fewer ESA restrictions where activities affect habitat but do not directly injure individual protected animals. The outcome is likely to have substantial implications for land-use planning, project permitting, conservation programs, and environmental compliance obligations nationwide.
The potential impact of the changes on a project will depend on the strength of endangered species protection afforded by relevant state law. For example, New Jersey’s Coastal Zone Management Rules prohibit development that adversely affects listed species habitat directly or through secondary impacts. N.J.A.C. 7:7-9.36. Similar regulations apply to the Highlands and freshwater wetlands. Statewide, proposed projects within mapped habitat for threatened and endangered species must either conduct an impact statement demonstrating no adverse effect or conduct a habitat evaluation to demonstrate that the site does not constitute suitable habitat.
For more information, please contact the authors of this post or the CSG Law Environmental Group.