One of the most powerful environmental protection laws is under threat
Defending the Endangered Species Act from federal attack
The Endangered Species Act (ESA) is one of the most powerful and successful environmental protection laws in the United States. Since its passage in 1973, it has prevented the extinction of 99% of the species it protects. A large part of that success is due to the law’s protection of habitat areas necessary for the survival of threatened and endangered species. Now, a new proposal from the U.S. Fish and Wildlife Service and the National Marine Fisheries Service threatens to undercut that foundation.
On April 17, 2025, the Services proposed eliminating the regulatory definition of “harm” under the ESA. This proposed rulemaking is a dangerous rollback of a core protection that has stood for decades.
What does “harm” really mean — and why it matters to wildlife
Right now, the ESA prohibits actions that “take” threatened and endangered species — activities that kill, injure, or otherwise harm these species are considered illegal under the statute. The federal regulatory definition of “harm” prohibits not just actions like hunting, trapping, or poaching, but also significant habitat destruction and modification that results in injury or death to protected species. This definition extends the ESA’s protections beyond activities that target wildlife directly to include threats to the critical habitats necessary for their survival and recovery.
Whether it’s filling wetlands, cutting down forests, or building in sensitive river corridors, destroying habitat kills wildlife.
This interpretation was upheld by the U.S. Supreme Court in the landmark 1995 case Babbitt v. Sweet Home. The Court recognized that habitat destruction leading to injury or death of protected species falls within the scope of prohibited actions under the ESA. The Court emphasized that the ordinary meaning of “harm” encompasses actions that indirectly cause injury through habitat alteration, aligning with the Act’s broad purpose of preventing species extinction.
Removing the regulatory definition of “harm” could make it significantly harder to hold people and developers accountable for habitat destruction, even when it results in the death of endangered animals. As a result, many species will face an even greater risk of extinction.
The sturgeon’s story: A Hudson River icon at risk
At Riverkeeper, we see the stakes firsthand. The Atlantic and shortnose sturgeon are well-known symbols of the Hudson River and were once a major part of New York’s commercial fishing industry, but now, they are both federally listed as endangered species. These species, often called "living dinosaurs," have persisted for millions of years in the Hudson River yet currently face serious threats due to overfishing, habitat destruction, and other human impacts. Strong federal regulations are more important than ever to limit and prevent habitat loss are essential to ensure the survival of these species, preserve biodiversity, and support freshwater and marine ecosystem services.
Both the Atlantic and shortnose sturgeon rely on specific parts of the river to reproduce and survive. But dredging, pollution, boat traffic, and development have already devastated large areas of their habitat. If the definition of “harm” is rescinded, it could open the door to even more degradation with fewer legal safeguards.
Since its passage in 1973, the Endangered Species Act has prevented the extinction of 99% of the species it protects
The Hudson River is not an easy place for a species to recover. To support the iconic sturgeon, Riverkeeper has relied on the ESA in a variety of ways to protect critical sturgeon habitat areas:
Champlain Hudson Power Express
The Champlain Hudson Power Express (CHPE) project, a 339-mile transmission project from Canada to New York, including approximately 90 miles of cable in the Hudson River, is subject to the ESA. The project’s developers were required to consult with the Fish and Wildlife Service regarding potential impacts to federally listed and proposed species and their critical habitats to ensure that the project does not jeopardize such species or destroy, or adversely modify, their critical habitat.
As a result of Riverkeeper’s efforts, the final project route avoids Atlantic sturgeon habitat and minimizes impacts to sensitive areas, including the designated sturgeon spawning area in Haverstraw Bay, extending six miles in the Hudson River from Stony Point to Croton Point. In addition, underwater cable installation activities are limited to certain times of the year to avoid life-cycle or migratory impacts to Atlantic sturgeon, American shad, winter flounder, striped bass, and other “anadromous” fish populations (fish that spend most of their lives in saltwater but return to freshwater to spawn), as well as resident species such as shortnose sturgeon using the affected areas. These construction windows help to further reduce impacts to important Hudson River species, particularly the endangered Atlantic and shortnose sturgeon populations.
CHPE is also required to perform pre-installation and post-installation studies of adult Atlantic sturgeon to ensure that aquatic environmental impacts are minimized during cable installation. The study will evaluate the movement patterns of spawning Atlantic sturgeon from the effects of the installation of the high voltage line and the magnetic field emitted by the operation of the cables. The study will determine if the fish tend to avoid or are attracted to the areas where the cables are installed.
To establish additional anchorage grounds in the Hudson River, the Coast Guard would need to comply with the ESA and demonstrate that such action would not likely jeopardize the continued existence of any endangered species. At a minimum, the Coast Guard must consult with the appropriate federal agencies regarding the potential harm to the Hudson River’s sturgeon population, including its critical habitat areas.
Construction of the new Tappan Zee Bridge
In July 2015, Riverkeeper petitioned the National Marine Fisheries Service to investigate whether bridge construction was killing Atlantic and shortnose sturgeon and take immediate action. In response to Riverkeeper’s concerns, NMFS released new, updated project requirements to protect the sturgeon.
Habitat loss is the #1 driver of extinction
Habitat loss is the primary factor in nearly 85% of species population declines worldwide and is the greatest single threat to a species’ existence. Whether it’s filling wetlands, cutting down forests, or building in sensitive river corridors, destroying habitat kills wildlife.
The ESA was written to address this threat. Its very purpose is “to provide a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved.” The law is not just about saving individual animals, it is about preserving the natural systems that make life possible.
That’s why including habitat destruction within the definition of “harm” is both logical and essential. Without it, the ESA loses much of its power to prevent extinction.
Habitat loss is the primary factor in nearly 85% of species population declines worldwide
Federal leadership is crucial
The ESA was created to provide a comprehensive, science-based framework to protect imperiled species and the ecosystems they depend on. This national framework is complemented by state programs, such as the New York State Endangered Species Act. Together, federal and state efforts provide layered protections for threatened and endangered species.
Endangered species do not recognize political or state boundaries. Fish like sturgeon migrate between state waters and the open ocean. Federal protections ensure that species are safeguarded no matter where they go, and that habitat destruction in one state doesn’t undermine conservation efforts elsewhere.
States play an important role in protecting wildlife, but they can’t go it alone. Weakening the federal ESA framework, especially by stripping away key habitat protections, would create inconsistency, confusion, and gaps in enforcement across the country.
What we stand to lose
If the Services succeed in rescinding the definition of “harm,” they will be discarding decades of scientific consensus, legal precedent, and regulatory practice. They will also be abandoning a critical tool for preventing the silent, invisible losses that come when habitats are damaged beyond repair.
Make no mistake: This change will put endangered species in greater danger. Not just sturgeon in the Hudson, but sea turtles on the Gulf Coast, salamanders in Appalachian streams, and owls in old-growth forests.
The future of the ESA — and the species it protects — is hanging in the balance.
You can help save sturgeon
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