Colorado River fish pulled back from extinction

DENVER — Another rare Colorado River fish has been pulled back from the brink of extinction, wildlife officials said Thursday, the second comeback this year for a species unique to the southwestern U.S.

The U.S. Fish and Wildlife Service recommended reclassifying the ancient and odd-looking razorback sucker from endangered to threatened, meaning it is still at risk of extinction, but the danger is no longer immediate.

Hundreds of thousands of razorbacks once thrived in the Colorado River and its tributaries, which flow across seven states and Mexico.

By the 1980s they had dwindled to about 100. Researchers blame non-native predator fish that attacked and ate the razorbacks and dams that disrupted their habitat.

Their numbers have bounced back to between 54,000 and 59,000 today, thanks to a multimillion-dollar effort that enlisted the help of hatcheries, dam operators, landowners, Native American tribes and state and federal agencies.

“It’s a work in progress,” said Tom Chart, director of the Upper Colorado River Endangered Fish Recovery Program. “We get more fish out in the system. They’re showing up in more places. They’re spawning in more locations.”

Chart’s program oversees the campaign to restore the razorback sucker and three other fish, all of them found only in the Colorado River system.

In March, the Fish and Wildlife Service recommended changing the status of the humpback chub from endangered to threatened. It takes 18 to 24 months to complete the process.

The razorback sucker’s name comes from a sharp-edged, keel-like ridge along its back behind its head. Chart thinks the ridge may have evolved to help the fish stay stable in the turbulent waters of the Colorado.

It can grow up to 3 feet long and live up to 40 years.

Razorbacks have been around for between 3 million and 5 million years, but trouble arrived as the population expanded in the Southwest. State and federal agencies began introducing game fish into the Colorado without realizing they would devour the native fish, Chart said.

Dan Elliott The Associated Press A Colorado River razorback sucker fish is shown swimming in a tank at the U.S. Fish and Wildlife Service office in Lakewood, Colo.