Trout face high stress in Colorado

? Low flows in Colorado’s rivers and streams, combined with unseasonably warm temperatures have prompted Colorado fisheries biologists to ask anglers to help minimize stress on the state’s trout population.

Greg Policky manages the aquatic resources in the Upper Arkansas River basin and he says a lack of snowmelt runoff is causing the Arkansas to run lower and warmer than normal for this time of year.

“Cloudy afternoons and occasional rain showers can cool the water somewhat, but one can only speculate as to how warm the river may get as the summer progresses,” Policky said.

Trout begin to behave differently at temperatures over 65 degrees. They move to cooler water and feed at cooler times of the day.

“Trout can show significant stress when temperature rises into the mid-70’s for several successive days,” Policky said.

Policky said there are steps anglers can take to help alleviate stress on fish.

“Carry a thermometer and when water temperature rises above 65 degrees, either call it quits for the day or move upstream where temperatures are cooler,” he said. “The fish won’t bite well when the water is warmer than 65 anyway.”

Policky is asking people to report curious fish behavior such as easily spooked or lethargic fish hugging the water surface, equilibrium problems or large numbers of dead or dying fish.

He said there are over 2,000 trout per mile in the Arkansas River, so a few dead fish here and there is of no concern but several hundred is something the DOW wants to know about.