A coalition of 21 state attorneys general is challenging the Trump administration’s changes to the Endangered Species Act (ESA), setting up a legal fight over rules that could affect commercial fisheries, species protection, and marine habitat.

California Attorney General Rob Bonta co-led two lawsuits filed against the U.S. Fish and Wildlife Service and NOAA Fisheries. The states are challenging revisions involving the definition of “harm,” critical habitat designations, and protections for species listed as threatened.

The lawsuits ask the U.S. District Court for the Northern District of California to vacate the rules, arguing they violate the Endangered Species Act, the Administrative Procedure Act, and the National Environmental Policy Act.

The changes could be particularly relevant to commercial fishermen because NOAA Fisheries administers the ESA for many marine and anadromous species. ESA protections can influence fishing regulations, federal permitting, habitat protections, and measures intended to reduce interactions with protected species.

What could change for fishermen?

One of the most significant changes involves the definition of “harm” under the ESA’s prohibition against the “take” of listed species. The states argue the revised definition weakens the federal government’s ability to treat habitat destruction or degradation as harm when it ultimately kills or injures a protected species.

For fisheries, changes to how “harm” is interpreted could affect the regulatory framework surrounding protected marine species and their habitat. Depending on how the rule is applied, it could narrow circumstances in which habitat impacts are considered an unlawful take under the ESA.

Another rule changes how areas can be excluded from critical habitat designations. Under the ESA, critical habitat can include areas containing physical or biological features essential to conserving a listed species, and federal agencies must consider impacts to designated habitat when taking federal actions.

The administration's revision expands consideration of economic, national security, and other impacts when determining whether areas should be excluded. The states argue the change could result in less habitat receiving federal protection.

For commercial fishermen, that could become relevant when critical habitat overlaps fishing grounds or when federal fishery actions undergo ESA review. Critical habitat designations do not automatically close an area to fishing, but they can affect federal decisions involving activities that may destroy or adversely modify habitat.

The third disputed change involves protections under Section 4(d) of the ESA. Section 4(d) allows agencies to establish protections for threatened species, including restrictions otherwise automatically applicable to endangered species. NOAA Fisheries says those rules can be tailored to a species' biology, conservation needs, and threats.

The states argue the new approach leaves newly listed threatened species without sufficient protections while species-specific rules are developed.

States challenge rollback

Bonta is leading the legal challenge alongside attorneys general from Maryland, Massachusetts, and Washington. The coalition includes Arizona, Colorado, Connecticut, Delaware, Hawaii, Illinois, Michigan, Minnesota, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, Virginia, Wisconsin and the District of Columbia.

“For too long, the Endangered Species Act has been weaponized to stop almost any new project in America, driving up costs for families, weakening our competitiveness, and undermining our national security,” Interior Secretary Doug Burgum said in announcing the changes, according to ABC News.

Bonta, meanwhile, characterized the revisions as unlawful changes that would reduce protections for habitat needed by vulnerable species.

The legal challenge leaves the future of the rules uncertain. For the fishing industry, the outcome could help determine how NOAA Fisheries applies one of the country's most consequential environmental laws to marine species, habitat and federally managed activities.

The lawsuits now seek to have the three rules set aside, potentially returning the agencies to the previous regulatory framework if the states prevail.