New Endangered Species “harm” rule: the impact and why it’s headed to SCOTUS

The Department of the Interior and the Department of Commerce this month announced a finalized rule rescinding the regulatory definition of “harm” under the Endangered Species Act. The Departments stated their action “returns the interpretation of the ESA back to its actual text and original intent, which will end years of federal overreach.” The Final Rule will be effective September 14, 2026.

Here are my initial thoughts on the impacts of this change:

1. The regulatory definition of “harm” is the only source of habitat protection provided to species listed as endangered or threatened under the Endangered Species Act. Designated Critical Habitat is treated differently, and then only under ESA Section 7. In short, habitat necessary for ESA-listed species is no longer protected from modification or degradation.

2. After the effective date of the rule, there will be significant changes to ESA Section 7 consultations. Under Section 7, federal agencies must consult with the USFWS and/or National Marine Fisheries Service when any action the agency carries out, funds, or authorizes may affect a species listed as threatened or endangered, or any critical habitat designated for such species. 

3. It’s unclear what guidance USFWS biologists will receive regarding Section 7 consultations; technically, Section 7 evaluates impacts not take.  However, federal court rulings instruct the agencies to evaluate take as well and in some cases, only take.  The vast majority of mitigation offsets requested by the USFWS usually result from impacts to a listed species’ habitat. With the rescission of the harm rule, mitigation for impacts to habitat will no longer be required, as these impacts will no longer be considered take under Section 9 of the ESA.

4. There is also the question of whether USFWS will continue to request mitigation offsets for adverse impacts (not rising to the level of take), or just actual take.  Again, technically, mitigation is not required for non-jeopardy Biological Opinions but that often doesn’t stop USFWS from asking for it.

5. Under Section 7 of the ESA, minimization measures are only required to offset actual take. Consequently, federal projects can expect to see a reduction in the number of minimization measures they are asked to implement In the past, many of these minimization measures were linked to habitat modification or destruction. 

6. For Section 9 and Section 10 Habitat Conservation Plans (HCPs), harm is still referenced in the statute. All the rescission rule rescinds is the current regulatory definition of harm established by the Supreme Court in 1995 in its Sweet Home decision. With the rescission, we are sent back to the pre-1995 regulatory environment. During this time, each judge ruling on an ESA habitat case (harm) would come up with his/her own definition of harm.  

Undoubtedly, there will be new conflicting rulings on the definition of harm eventually resulting in the matter getting to the Supreme Court again. 

Gary Mowad

Senior Advisor

Before joining Dawson & Associates in 2025, Gary spent 25 years at the US Fish & Wildlife Service, where he was one of the agency’s top authorities on Endangered Species Act issues.