The law firm Earthjustice, alongside more than half a dozen environmental groups, filed a lawsuit Tuesday in U.S. District Court in Seattle against the U.S. Fish and Wildlife Service and NOAA Fisheries, the agency that oversees marine species. The suit challenges the administration’s decision to rescind the regulatory definition of “harm” that for decades had included “significant habitat modification or degradation” that could affect a species’ ability to feed, reproduce or seek shelter.

The Trump administration announced the change Friday, July 10, and published it in the federal register Tuesday. Interior Secretary Doug Burgum said in a statement that the action “restores common sense, respects private property, provides much-needed certainty for landowners and follows the statute Congress actually passed.” A NOAA Fisheries representative said the rule “will restore the definition of ‘harm’ to its original intent as written under the ESA” and “maintain protections for endangered species while reducing unnecessary or duplicative permitting requirements.”

Kristen Boyles, an attorney with Earthjustice, told NPR that the agencies “haven’t explained themselves adequately.” She said the change “goes against the fundamental purpose and spirit of the statute itself,” making it “an unreasoned and unreasonable decision.” Boyles said the repeal would cause “complete confusion in the regulated community” and “an increase in litigation over each and every project that’s proposed that doesn’t protect habitat.”

The Endangered Species Act, signed into law by President Richard Nixon in 1973, prohibits the “taking” of endangered species, which the U.S. Fish and Wildlife Service defined to include “harm.” The agency’s interpretation that “harm” covers habitat destruction was upheld by the Supreme Court in a 6-3 decision in 1995, in Babbitt v. Sweet Home Chapter of Communities for a Great Oregon. Justice Antonin Scalia dissented, writing that the interpretation represented a “ruthless dilation of the word.”

Tara Zuardo, a senior campaigner at the Center for Biological Diversity, said the change effectively removes the most important threat to imperiled species. “For most all species, the number-one driver of extinction [is] damage and harm to their habitat,” Zuardo said. “So if you’re no longer counting that as harm under the law, you’re not going be able to protect any of the listed species.”

The Swinomish Indian Tribal Community and the Squaxin Island Tribe filed a separate lawsuit in U.S. District Court against the federal government. In their complaint, the tribes said that habitat degradation has been the primary cause of salmon stock losses in Puget Sound, and that “the loss of long-standing protection for the habitat of ESA-listed salmon species will injure the Tribes and their members.”

Industry groups have voiced support for the administration’s move. In public comments during the rulemaking process, a coalition of oil and petroleum groups including the American Petroleum Institute wrote that the “proposal to rescind the ‘harm’ definition is justified many times over.” The Associated General Contractors of America said they “appreciate the administration’s efforts to reduce unnecessary regulatory burdens.” Holly Hopkins of the American Petroleum Institute said in a statement that the group remains “committed to supporting commonsense ESA policies that both protect wildlife and support American energy leadership.”

Holly Doremus, a professor of environmental law at UC Berkeley, said the Endangered Species Act was designed as a temporary emergency measure — “a kind of triage for species nearing extinction.” She said the law’s habitat protection was intended to prevent exactly the kind of degradation that the new rule excludes from the definition of harm. “They wanted to be clear that if you, for example, removed the place where it nests, even if it was not there at the time, you would be hurting it,” Doremus said.

The new rule is scheduled to take effect on September 14. Boyles said the legal dispute over the definition of “harm” will likely result in prolonged uncertainty for developers, landowners, and conservationists alike.