"DENVER — The humpback chub, a rare fish found only in the Colorado River basin, has been brought back from the brink of extinction after decades of protection, though work must continue to ensure its survival, federal authorities said Monday in reclassifying the species from endangered to threatened status.
The fish, which gets its name from a fleshy bump behind its head, was first listed as endangered in 1967, its habitat severely disrupted by dam construction. Its numbers also declined with the introduction of predatory, non-native aquatic species.
Its change in status formally takes effect Nov. 17 under a rule published Monday in the Federal Register by the U.S. Fish and Wildlife Service.
Environmentalists oppose the endangered status delisting. They argue the humpback chub’s future remains in peril as a megadrought, largely attributable to climate change, diminishes flows in the Colorado River basin, which includes seven Southwestern U.S. states and Mexico."