The U.S. Supreme Court on Tuesday unanimously remanded an Endangered Species Act (ESA) case that's of interest to the oil and gas industry back to an appellate court and ordered the court in New Orleans to decide what constitutes "habitat."

The case involves ESA protections that the Fish and Wildlife Service (FWS) extended to the dusky gopher frog, an endangered amphibian that breeds in ephemeral ponds and was once native to forested wetlands throughout the southern coastal United States, but is now found in a single pond in Mississippi. The case is Weyerhaeuser Co. v. U.S. Fish and Wildlife Service, No. 17-71.

The case is of interest to the oil and gas industry because any ruling against Weyerhaeuser, a private timberland company, could lead to areas prime for energy development being designated as critical habitat for other species, even if they are absent.

FWS declared the frog “endangered” under the ESA in 2001, and designated its habitat as "critical" in 2012. Weyerhaeuser sued after FWS designated land it owns in St. Tammany Parish, LA, as part of the frog's habitat, despite the animal's absence.

Although lower federal courts, including the Fifth Circuit Court of Appeals, have ruled against the company, Supreme Court Chief Justice John Roberts opined that "only the 'habitat' of the endangered species is eligible for designation as critical habitat.

"Even if an area otherwise meets the statutory definition of unoccupied critical habitat because the [FWS] secretary finds the area essential for the conservation of the species, [federal law] does not authorize the secretary to designate the area as critical habitat unless it is also habitat for the species," Roberts wrote.

The chief justice also took issue with the term "critical habitat," which environmental groups, including the Center for Biological Diversity (CBD), had contended did not need further clarification.

"That is no baseline definition of habitat -- it identifies only certain areas that are indispensable to the conservation of the endangered species," Roberts wrote. "The definition allows the secretary to identify the subset of habitat that is critical, but leaves the larger category of habitat undefined."

CBD attorney Collette Adkins said that while the ruling was disappointing, it didn't weaken protections for endangered wildlife.

"The dusky gopher frog's habitat protections remain in place for now, and we're hopeful the Fifth Circuit will recognize the importance of protecting and restoring habitats for endangered wildlife," Adkins said. "You can't conserve endangered animals if you don't protect the places they need to survive and recover."

Brett Kavanaugh, who was confirmed to the Supreme Court last month, took no part in the consideration or decision of the case.