Colorado Pikeminnow-ES
From Glen Canyon Dam AMP
- The Colorado Pikeminnow, once known as squawfish, are now most common in the Green and Yampa rivers, through the 15-mile stretch of the Colorado River through the Grand Valley is considered critical to survival of the fish.
- The Pikeminnow population in the Green River has fluctuated between 2,200 and 4,500 and most recently has been on the increase. [1]
Pat Tierney — a professor and chairman of the Department of Recreation, Parks and Tourism at San Francisco State University — gathered the group on a sandbar, cobbled with stone, next to one of the most significant pikeminnow spawning beds in the Colorado River system.
- “The pikeminnow migrate as much as 200 miles,” Tierney said. “They come from the White River into the Green and up to this gravel bar. There has been a natural ecosystem here for thousands of years. They have a right to survive.” Scientists cannot directly view spawning pikeminnow because of the turbidity of the water, but they can “see” them spawning over specific spawning areas cobbled with river rocks thanks to radio tags. Mating begins within days of the mean daily water temperatures exceeding 64.4 degrees, Tierney said. After hatching, the juvenile fish drift downstream to a backwater that is cut off from the river’s main flow at the top but open to the current at the bottom. These warm backwaters provide abundant food for the first year of the pikeminnow’s life. Steamboat Today_Rise and fall of the Yampa River defines a unique ecosystem_July 14,2013
