Agencies Move To Rescind "Harm" Definition Under Endangered Species Act

On April 17, 2025, the U.S. Fish & Wildlife Service (USFWS) and National Marine Fisheries Service (NMFS) (collectively, Services) published a notice in the Federal Register proposing to rescind the Services' respective definitions of "harm" under the Endangered Species Act (ESA) (Proposed Rule). The notice indicates the Services will accept comments on the Proposed Rule until May 18.

Section 9 of the ESA prohibits "take" of endangered species and the Services have extended the "take" prohibition, by regulation, to many species listed as threatened under the statute. "Take" is defined by the ESA as to "harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct." The term "harm" is not defined by the ESA; instead, USFWS and NMFS have each promulgated definitions of the term which captures, under certain circumstances, modifying habitat of ESA-listed species.