Some drought-imposed fishing limits lifted on Colorado River

DENVER (AP) — Colorado lifted some fishing restrictions along a stretch of the Colorado River on Tuesday, but biologists warn that historically low water flows caused by a drought in the U.S. West, high water temperatures and wildfire sediment that all starve trout of oxygen could force future bans.

On July 7, Colorado Parks and Wildlife imposed a rare 120-mile (193-kilometer) voluntary fishing ban. Tuesday's changes allow anglers — a key driver of Colorado’s summer tourist economy — to fish a 27-mile (43-kilometer) stretch of river anytime between midnight and noon, when waters are cooler. Restrictions also have been partially lifted for 50 miles (80 kilometers) upstream.

The changes came after upriver reservoir releases, recent rain and a smaller amount of cold Colorado River headwaters being diverted to the Denver metro area on the eastern side of the Continental Divide, said Kendall Bakich, a Parks and Wildlife aquatic biologist.

Days of smoke from wildfires burning in Western states also has deflected solar radiation that heats up the river, slightly lowering temperatures, Bakich said.

“It’s crazy, but every little bit helps,” she said. “There have been such low flows beginning this spring that the Colorado River looks more like a creek than a river.”

A multitude of factors, nearly all tied to climate change, have left fish in the Colorado River and its many tributaries in a precarious state. Climate change has made the American West much warmer and drier in the past 30 years. While cold-water trout thrive in temperatures below 65 degrees Fahrenheit (18 Celsius), biologists have recorded temperatures surpassing 75 F (24 C).

Colorado’s Western Slope also experienced minimal spring runoff from the high Rocky Mountain snowpack this year — runoff that usually...