In a decision issued earlier this week, a U.S. District Court rejected the U.S. Fish and Wildlife Service’s (Service) interpretation of the Endangered Species Act (ESA), finding that its interpretation of the critical habitat designation requirement constituted an impermissible construction of the statute. Ctr. for Biological Diversity v. Kelly, Case No. 1:13-cv-00427 (D. Idaho Mar. 23, 2015) (pdf). Specifically, the court found that, contrary to the Service’s longstanding interpretation, the ESA requires critical habitat to be designated in a manner that would facilitate the recovery of a species.

The challenge to the Service’s interpretation of the ESA arose out of the Service’s 2012 final rule designating critical habitat for the endangered Southern Selkirk Mountains population of woodland caribou (Rangifer tarandus caribou). In 2011, the Service published a proposed rule that would designate approximately 375,562 acres as critical habitat for the caribou. In August 2012, however, the Service issued a draft final rule proposing to reduce the critical habitat designation by more than one-third, to approximately 227,100 acres. In November 2012, the Service published a final rule designating only 30,010 acres as critical habitat for the caribou. Shortly thereafter, a number of environmental organizations challenged the Service’s critical habitat designation, alleging that the designation violated the ESA because: (1) the Service failed to explain how the designation would provide for the recovery of the caribou; and (2) the Service was required to provide additional public notice and comment because the final rule was a substantial deviation from the proposed rule.

With respect to the issue of recovery, the court found that the Service’s interpretation “that its critical habitat designation need not ‘prove’ that it will ‘ensure’ the recovery of the species is contrary to the plain language and purpose of the ESA.” The court explained that “the whole point behind designating critical habitat is to identify those physical and biological features of the occupied area and/or those unoccupied areas that are essential to the conservation of a species with the aim of arriving at the point where the species is recovered, i.e., no longer in need of the measures provided for in the ESA.” Accordingly, the court found that the Service’s interpretation was contrary to law, and therefore not entitled to Chevron deference.

On the issue of additional public notice and comment, the court again sided with the plaintiffs, finding that such measures were required because the final was the product of “a fundamental and dramatic change in reasoning based on materials not previously discussed or cited in the Proposed Rule.”