Tag: Cutthroat trout

Global warming speeds diversity threats to native fish

Study looks at hybridization of trout in Northern Rocky Mountains

Biologists study trout in the Blue River in Silverthorne, Colorado. @bberwyn photo.

Staff Report

Global warming is intensifying the hybridization of native and non-native trout in the northern Rocky Mountains, according to a new study from the U.S. Geological Survey and other scientists. The trend is a serious threat to the biodiversity of Rocky Mountain aquatic ecosystems, says the study published in the journal Global Change Biology.

As non-native rainbow trout, introduced by early settlers, interbreed with cutthroat trout it leads to a decline in local adaptations that can threaten the long-term survival of species. Preserving the  genetic integrity of native species is important for  resiliency, the scientists said. Continue reading “Global warming speeds diversity threats to native fish”


Global warming making things tough for native trout in the northern Rockies

Cutthroat trout. Photo courtesy National Park Service.

30-year study shows how warmer stream temperatures are linked with hybridization

Staff Report

FRISCO — Scientists studying trout in the northern Rockies say warmer stream temperatures and lower spring flows in mountain streams is increasing the pace at which introduced rainbow trout and native cutthroats interbreed. Hybridization has already contributed to the decline and extinction of many native fishes worldwide, including all subspecies of cutthroat trout in western North America.

The long-term research shows that, while hybridization used to be limited to lower stream reaches, during the past 30 years, it has quickly spread upstream as temperatures warm. According to the scientists, the process is irreversibly reducing the genetic integrity of native westslope cutthroat trout populations. Genetically pure populations of westslope cutthroat trout are known to occupy less than 10 percent of their historical range. Continue reading “Global warming making things tough for native trout in the northern Rockies”

Environment: Ambitious Swan River restoration project near Breckenridge could benefit cutthroat trout

Forest Service wants to reconnect an aquatic ecosystem that was sliced apart by dredges in the mining era

Restoration plans are afoot for a degraded section of the Swan River, in Summit County, Colorado.
Restoration plans are afoot for a degraded section of the Swan River, in Summit County, Colorado.

By Bob Berwyn

FRISCO — For all the gold Summit County’s old-timers managed to pull from local mountains and rivers, they left behind quite a mess. Along with toxic pollution oozing into rivers from some abandoned mines, other streams were turned completely inside-out, buried under tons of gravel.

That includes the Swan River, near Breckenridge, where the U.S. Forest Service now hopes to reverse some of the damage with an ambitious five- to 10-year restoration project.

The Forest Service aims to recreate of two miles of stream, riparian, and restore uplands that were all destroyed by the dredge boats. The agency also wants to decommission some roads in the area, build a new road and trail, all within a mix ownership of private, county, town, and national forest lands. Another element of the project would create fish barriers to protect populations of cutthroat trout. Continue reading “Environment: Ambitious Swan River restoration project near Breckenridge could benefit cutthroat trout”

Summit Voice: Most-viewed and week in review

Fishing disasters in Alaska, the Gulf of Mexico and New England may all be linked with global warming.

Fracking, cutthroat trout and Colorado weather …

Environment: Probe of Arctic scientist ends inconclusively

SUMMIT COUNTY —A Kafka-esque federal probe of a polar biologist ended inconclusively this week, as biologist Charles Monnett got a mild slap on the wrist for an alleged breach of policy that was unrelated to the focus of the 2.5-year investigation.

Climate: Ocean temps rising especially fast along coasts

SUMMIT COUNTY — Scientists with the UK’s University of Southampton say they may have documented another unanticipated global warming feedback loop, as sea surface temperatures in coastal regions appears to be rising up to 10 times faster than the global average. Continue reading “Summit Voice: Most-viewed and week in review”

Colorado: Some cutthroat trout mysteries solved

What next for Colorado’s state fish?

A Rio Grande cutthroat trout. Photo courtesy Andrew Todd.

By Bob Berwyn

SUMMIT COUNTY — After some genetic sleuthing and intensive scrutiny of historic fish-stocking records, a team of federal, state and university biologists said they’ve pinned down Colorado’s greenback cutthroat trout to just a single population — about 750 fish, all living in a four-mile reach of Bear Creek, a small Arkansas River tributary in the mountains west of Colorado Springs.

Greenback cutthroats — the Colorado state fish — were originally native to the South Platte drainage, but now appear to survive only in that single population outside of the species’ native range.

Biologists say native cutthroats in Colorado declined because of  pollution, overfishing and stocking of native and non-native species of trout. Continue reading “Colorado: Some cutthroat trout mysteries solved”

Morning photo: Fishing!

Licenses for the 2012-2012 season on sale; state fishery experts warn against ‘bucket biology’

Fishing in glassy water at a "hidden" cove along the shore of Dillon Reservoir.

By Summit Voice

SUMMIT COUNTY — Early spring weather might not be the best thing for skiers looking to extend the season, but it could be good news for Colorado anglers looking to get early access to high country lakes and streams.

And with the 2o12-2012 license year just a few weeks away, it could be a good time to make sure you’re ready by buying or renewing your license. The latest fishing brochure, with regulations and other info, is also available where licenses are sold and online at http://www.flipseekpubs.com/publication/?i=99616.

Memorial Day fishing at the Dillon Marina.

Continue reading “Morning photo: Fishing!”

Global warming to take big toll on western trout

Habitat expected to shrink by 50 percent in coming decades

Anglers may have to climb high to find fish as global warming takes a toll on trout.

By Bob Berwyn

SUMMIT COUNTY — A combination of rising temperatures and changes in the timing of runoff and streamflows could reduce trout habitat in the western U.S. by about 50 percent during the next 70 years, with some populations disappearing completely within just a few decades.

The mechanisms for temperature-driven extirpations are complex, but the bottom line is that an ever-warming world isn’t going to leave much room for cold-blooded fish.

“They operate within a very narrow temperature range,” said U.S. Geological Survey biologist Andrew Todd. Variations in temperature can affect spawning, even if the temperatures don’t reach levels that are directly lethal to the fish, Todd said.

And the hydrology is also important, he explained. Even small changes in the amount and timing of precipitation can have a big impact on smaller headwaters streams. And unlike birds or mammals, trout don’t have the ability to move freely if conditions become unsuitable.

“They can’t just go to Montana,” Todd said. Continue reading “Global warming to take big toll on western trout”