May 15, 2025
Mr. Paul Souza
Acting Director
U.S. Fish and Wildlife Service
1849 C St., NW
Washington, DC 20240
Re: Rescinding the Definition of Harm under the Endangered Species Act; Docket No. FWS-HQ-ES-2025-0034
Dear Mr. Souza:
The American Fisheries Society (AFS) respectfully submits the following information in response to the proposed rule to rescind the regulatory definition of “harm” in Endangered Species Act (ESA or the Act) regulations.
AFS is the world’s oldest and largest professional society of fishery and aquatic scientists and managers. AFS seeks to improve the conservation and sustainability of fishery resources and aquatic ecosystems by advancing fisheries and aquatic science, promoting the development of fisheries professionals, and advocating for the use of best-available science in policy-making efforts.
We write today to share our perspective on the value of the Endangered Species Act and its importance to our nation’s fish and fisheries. We urge you to maintain our nation’s bedrock environmental laws, including the ESA. The ESA prohibits “take” of endangered species. The existing regulatory definition of “harm,” which includes habitat modification, is essential to a science-based ESA. AFS opposes the proposed change to the definition.
The ESA is a science-based tool for recovering America’s threatened and endangered species. The proposed change to the definition of harm to exclude habitat modification would undermine the scientific foundations of the ESA. The current regulation defines “harm” to include significant habitat modification that kills or injures species by significantly impairing essential behavior patterns, including breeding, feeding, or sheltering. This broad interpretation is intended to protect not just animals and plants themselves but the places they need to survive, such as spawning areas, nursery grounds, or migratory corridors. Harm, or the potential for harm, through habitat modification is the most prevalent form of take and it is essential for the definition of harm to include habitat modification. Limiting take to only directly killing or capturing endangered fish, which is extremely difficult to monitor, would undermine the law’s objective of protecting and recovering imperiled species and the ecosystems of which they depend. Fish need habitat to survive, grow, and reproduce.
The ESA has been the catalyst for successful delisting or down-listing of many endangered and threatened fish. The ESA has brought back several fish species from the brink of extinction, including the Apache Trout, Okaloosa Darter, Borax Lake Chub, Foskett Speckled Dace, Modoc Sucker, and Oregon Chub (see Appendix A)—all as a result of habitat protection, improvement, and restoration, and not by protecting fish from direct killing. In the alternative, if we lose this protection for habitat, more species will go the way of the Harelip Sucker, a fish that was once widely distributed in the southeastern U.S. It is now extinct due to harm created from habitat damage as a result of sediment pollution, rather than from direct killing.
Importance of Habitat
Habitat loss is the leading factor in species population declines in the U.S. In fact, habitat loss is estimated to impair more than 80% of known species and is the greatest single threat to species existence (Hogue and Breon 2022). In passing the ESA, Congress recognized that listed species depend on entire ecosystems. Indeed, many ESA petitions and listings have identified the loss of usable habitat or access to habitat as the primary reason for the decline in species. Increases in water temperature, insufficient levels of water in streams and rivers, poor water quality, and non-native invasive species have led to the imperilment of 40% of all freshwater species (Su et al. 2021). Any definition of “habitat” must account for a wide enough variety of situations to ensure the ecosystems that support and maintain listed and vulnerable species can be conserved. A broader definition allows for more tools in the conservation “tool box.” This flexibility is particularly important in the face of anthropogenic, detrimental climate change. A dual approach of both protecting existing quality habitat and increasing occupiable habitat is necessary to sustain species into the future, prevent listings, and achieve delistings.
Successful conservation efforts for species protection and recovery require holistic watershed approaches (e.g., Native Fish Conservation Areas like the Little Tennessee River and Willamette River for Oregon Chub) and partnerships across state, federal, and non-profit groups and landowners. Increasing healthy habitat is the key to delistings, a shared goal amongst conservationists, developers, and the general public. If we lose habitat protection as part of the definition of “harm,” AFS professionals know the consequence is extinction for many more species.
AFS stands ready to provide you with additional information should you have any questions. Thank you for your consideration.
Sincerely,
Jeff Kopaska
Executive Director
