A trout species thought to be extinct was discovered alive and well last year in a small stream in Southwest Colorado. Now, the waterway will be preserved to protect the fish.
The Colorado Water Conservation Board earlier this month unanimously approved an “instream flow” protection for a 2-mile stretch of the creek where the trout were found – a designation that says water must stay in the river for the benefit of the environment, barring future development that would take water out.
Attempts to reach the CWCB were unsuccessful Friday.
Cutthroat trout originated in the Pacific Ocean but eventually moved inland and adapted to cold streams and rivers throughout the American West, evolving through geographic isolation into 14 subspecies.
But for various reasons including the impact from Western settlement, many of the fish have disappeared or struggled to exist on the landscape.
For more than 30 years, aquatic biologists have surveyed remote creeks in Southwest Colorado, looking for isolated populations of native cutthroat trout. Realizing the remote populations of fish might carry traits and adaptations that could be revealed through genetic testing, biologists stowed away samples.
Last year, DNA testing linked a cutthroat found in the San Juan River basin to fish samples collected and preserved in 1874 by naturalist Charles E. Aiken, who donated two trout to the Smithsonian National Museum of Natural History.
Mike Japhet, a retired CPW biologist who helped discover the San Juan lineage of Colorado River cutthroat trout in the early 1990s, said researchers at the time suspected a connection, but the DNA testing left no doubt.
“It was super-exciting,” Japhet said. “It’s like going on a treasure hunt and finding you really discovered a hidden treasure.”
Officials also plan to protect the cutthroat by keeping its location secret.
The instream flow right was a result of years of data collection and analysis by the U.S. Forest Service and Colorado Parks and Wildlife, said Ryan Unterreiner, the Southwest region water resource specialist for CPW.
The remoteness of the creek and its location on U.S. Forest Service land played a pivotal role in securing the water right and further protects the area from being developed.
In Colorado, the only entity that can hold a water right that keeps water in a river is the Colorado Water Conservation Board for environmental purposes. In the 1970s, with growing public concern about waterways drying up because of overuse, the CWCB created the “instream flow program” to acquire water rights to keep water in rivers.
Since then, the program has contributed to preserving more than 9,700 miles of streams and 480 natural lakes in the state.
Unterreiner said the cutthroat need the natural fluctuations of water flows to survive.
“In order to preserve that natural environment, we needed all the unappropriated waters,” Unterreiner said. “That’s what they’ve had for a millennium, and that’s what they need in the future.”
Anthony Madrid, with the Forest Service, said the creek that received instream flow protections was one of the most at-risk streams that bear San Juan lineage Colorado River cutthroat trout.
“The motion to file an instream flow ... is important to the Forest Service because it ensures that water will remain in the stream, providing both base flows as well as peak flows, which generate the turbulence and shearing necessary to maintain step-pool channels and over-wintering habitat,” he said.
Joe Lewandowski, spokesman for CPW, said there’s no good estimate how many populations of San Juan lineage cutthroat trout may exist in the wild, but he said measures are being taken to reintroduce the fish when possible.
In recent years, CPW has taken the native fish from small streams throughout the region and started a brood stock. The intent, he said, is to eventually reintroduce the fish in creeks and streams that present suitable habitat.
jromeo@durangoherald.com
