Center for Biological Diversity v. Zinke

The Ninth Circuit Court of Appeals ruled that the U.S. Fish and Wildlife Service (FWS) had acted arbitrarily and capriciously in certain respects when it determined not to list the Upper Missouri River Valley distinct population segment of arctic grayling as endangered or threatened. The arctic grayling prefers cooler waters and is threatened by climate change. While the Ninth Circuit held that the FWS did not err in considering only the current range of the arctic grayling when determining whether it was in danger of extinction “in all or a significant portion of its range,” the Ninth Circuit found that the FWS acted arbitrarily and capriciously when it (1) ignored available data that a population of arctic grayling was declining; (2) arbitrarily relied on the ability of the arctic grayling to migrate to cold water refugia; and (3) failed to explain why the uncertainty of climate change favored not listing. The Ninth Circuit remanded to the FWS for reassessment of its findings.