Natural Resources and Mining Law Blog
On October 11, 2025, Governor Gavin Newsom signed Assembly Bill 1319 into law, establishing a new California Endangered Species Act (CESA) mechanism for California to extend state-level endangered species protections to species that may lose federal safeguards under the federal Endangered Species Act (ESA). The statute empowers the California Department of Fish and Wildlife (CDFW) to designate “provisional candidate species” that receive the same protections as state-listed species, including strict prohibitions on “take” and rigorous mitigation requirements.
AB 1319 is California’s direct response to a material shift in federal endangered species law—one triggered by the Supreme Court’s 2024 decision in Loper Bright Enterprises v. Raimondo and the subsequent federal proposal to rescind the regulatory definition of “harm” under the Endangered Species Act. These federal changes threaten to narrow the scope of activities regulated under the ESA, particularly those involving habitat modification. California’s new law seeks to ensure that species native to the state will continue to receive protection even if federal safeguards are reduced or eliminated.
The implications are significant: there are dozens of federally listed or candidate species native to California that are not currently protected under CESA—any of which could become provisional candidates under AB 1319 if federal protections are reduced. California’s new law seeks to ensure that these species will continue to receive protection even if federal safeguards are eliminated.
For mining companies operating in California, this federal-state divergence could create significant compliance challenges. A project might qualify for expedited federal environmental review under the Trump Administration’s new policies while simultaneously triggering prolonged state permitting delays and high mitigation costs for species that no longer receive federal protection. Understanding this evolving regulatory landscape will enhance project planning and risk management.
The Federal Regulatory Changes: From Babbitt to Loper Bright
The Endangered Species Act prohibits the “take” of any species listed as endangered or threatened. 16 U.S.C. § 1532(19) defines “take” to mean “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct.” This prohibition is the ESA’s primary mechanism for protecting listed species.
The term “harm” within this definition has been the subject of significant regulatory and judicial interpretation. For three decades, federal regulations defined “harm” to include “significant habitat modification or degradation where it actually kills or injures wildlife by significantly impairing essential behavioral patterns, including breeding, feeding, or sheltering”. This definition was upheld by the Supreme Court in 1995 in Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, with the Court’s majority concluding that the regulatory definition was a reasonable interpretation entitled to deference under the Chevron doctrine.
The legal landscape shifted fundamentally in June 2024 when the Supreme Court decided Loper Bright Enterprises v. Raimondo, overturning the Chevron doctrine. The Court held that courts must exercise independent judgment in interpreting statutes, rather than deferring to agency interpretations. With Chevron overturned, the legal foundation supporting the regulatory definition of “harm” was called into question.
The April 2025 Proposed Federal Rule
On April 17, 2025, the U.S. Fish and Wildlife Service and National Marine Fisheries Service published a proposed rule to rescind the regulatory definition of “harm,” without providing a replacement. The agencies’ reasoning was direct: “[w]e have concluded that our existing regulations, which still contain the definition of ‘harm’ contested in Sweet Home, do not match the single, best meaning of the statute.”
The proposed rule’s rescission of the regulatory definition would likely narrow the scope of activities regulated under the ESA. Activities that modify or degrade habitat would no longer constitute ‘harm’ unless they directly and intentionally kill or injure individual animals. The public comment period closed on May 19, 2025, and the rule has not yet been finalized.
AB 1319 Process, Protections, and Requirements
AB 1319 requires CDFW to monitor federal actions that could result in “decrease in protections” for species that are: (1) native to California, (2) federally listed or candidates as of January 1, 2025, and (3) not currently protected under CESA. A “decrease in protections” includes federal actions that delist species, downlist them from endangered to threatened, eliminate or change take prohibitions, or decrease mitigation requirements.
When CDFW identifies such a federal action, it must determine whether: (1) the decrease will substantially impact one or more species in California, and (2) provisional listing could significantly reduce that impact. If both conditions are met, CDFW must publish written findings in the California Regulatory Notice Register designating the species as a “provisional candidate.”
“Provisional candidate” species receive the same protections as candidate species under CESA. This includes the prohibition on “take” under Fish and Game Code Section 2080 and the requirement that any authorized take be “minimized and fully mitigated” under Section 2081. In practice, this means projects affecting provisional candidates must obtain state incidental take permits with comprehensive mitigation, even if federal authorization is no longer required. There are dozens listed or candidate species native to California that are not state-listed—any of which could become provisional candidates under AB 1319 if federal protections are reduced.
California’s Pattern of Filling Federal Gaps
AB 1319 continues California’s pattern of maintaining environmental protections when federal standards are reduced. The state has previously defended its vehicle emissions standards against federal rollbacks, clarified that state water quality laws cover waters that lost federal protection, and used state authority to deny permits for projects that conflict with state environmental policies despite federal approval.
The current administration has pursued aggressive permitting acceleration for certain mining projects, with DOI emergency rules compressing environmental review timelines to as little as 14 days for Environmental Assessments and 28 days for Environmental Impact Statements for critical minerals. But such federal efforts encounter California’s determination to maintain environmental review standards through state-specific statutes such as CESA, which requires that impacts be “minimized and fully mitigated”—a standard significantly stricter than federal law.
Conclusion
AB 1319 represents California’s effort to maintain endangered species protections in the face of federal regulatory changes. For mining companies, it presents a potentially significant compliance challenge: navigating a regulatory landscape where federal and state requirements diverge. If the federal rescission of the “harm” definition is finalized, activities that have required federal permits could fall outside federal regulation. But in California, that change will be met with state-level protections, potentially adding many species to the list requiring state permits and mitigation.