Trump administration redefines 'harm' under Endangered Species Act; groups update lawsuit

A Trump administration rule change took effect on 14 September 2026 that redefines "harm" under the Endangered Species Act to mean only directly killing a member of an endangered species. 1 2 The new definition removes an interpretation used for half a century and upheld by the Supreme Court, under which harming a species included eliminating its habitat. 1 On the same date, US Fish and Wildlife Service Director Brian Nesvik issued a memo interpreting the law as covering only intentional killing, which critics say effectively allows "incidental" killing. 2 1

John Luce, general counsel at the National Oceanic and Atmospheric Administration, sent the same directive to eight sections of NOAA. 2 The administration has also finalized removal of the Blanket 4(d) Rule, which gave automatic protections to species listed as "threatened"; without it, each threatened species depends on species-specific rules that can take years to draw up. 1 A coalition including the Center for Biological Diversity, Sierra Club and WildEarth Guardians, represented by Earthjustice, sued in July over the rescission and on Thursday 1 October filed a supplemental complaint in federal court in Seattle. 2

The filing argues the memos violate the plain language and purpose of the ESA, lack a reasoned basis, are arbitrary and capricious, and skipped notice-and-comment rulemaking required under the Administrative Procedure Act; it asks the court to vacate them. 2 Noah Greenwald of the Center for Biological Diversity called the effort "despicable" and said it means "open season" on species on the brink; Earthjustice attorney Ben Levitan called the government's position "a prescription for extinction". 2 Conservation scientist Timothy Randhir of UMass Amherst writes that if the changes survive court challenges, shipping, logging, mining and development practices could be affected, and some species could face extinction. 1

He points to three species: the Florida panther (about 120 to 230 adults, a third of its main habitat on private land), the North Atlantic right whale (about 380 animals, roughly 70 breeding females), and the monarch butterfly (population down about 80% over a decade), which would have benefited from the Blanket 4(d) Rule. 1 Randhir argues the changes remove some legal basis for rules on seismic surveys, vessel speed limits and shipping routes meant to protect right whales, and would let landowners clear wildlife corridors without liability for harming panthers. 1