SHAUN STANLEY/Durango Herald
A long-planned move to re-establish the Colorado River cutthroat trout in the Hermosa Creek watershed occurred Wednesday when the headwaters stretch of the drainage was stocked with the native fish.
Colorado Parks and Wildlife biologists and volunteers, including Trout Unlimited, planted 11,000 fingerlings about 3 inches long and 200 10-inchers in the main stem of Hermosa Creek upstream from Hotel Draw.
Fish were carried in bags from trucks and emptied into Hermosa Creek at various points. If the fish had to be carried any distance, they were transported in super-oxygenated water to ensure they arrived in good condition.
Michael Martinez, a fish culturist at the Parks and Wildlife hatchery in Durango, brought the fingerlings Tuesday from the Rifle Falls hatchery in Garfield County.
“The water there has been certified free of whirling disease,” said Riley Morris, assistant manager at the Parks and Wildlife hatchery in Durango.
Whirling disease, caused by a parasite, results in skeletal deformation and neurological damage that cause the fish to swim awkwardly. Fingerlings are particularly susceptible.
Preparation for the stocking Wednesday began in August 2011, when about nine miles of Hermosa Creek above Hotel Draw was treated with Rotenone to kill non-native fish, mostly brook trout.
A barrier in the creek at Hotel Draw prevents the intrusion of non-natives.
This summer, biologists returned to the targeted stocking area to apply Rotenone again and electroshock survivors.
Rotenone, derived from the root of a tropical plant, is registered by the Environmental Protection Agency as a pesticide. It degrades rapidly, leaves no residue and is no threat to other wildlife or humans.
Native cutthroat trout don’t compete well with other species, so efforts to increase their population – they occupy only 14 percent of their historic habitat – focus on giving them exclusive use of certain waters.
“Some fishermen just want to catch a fish and eat it,” said Buck Skillen, a member of the 5 Rivers Chapter of Trout Unlimited and a volunteer with Parks and Wildlife. “But there are a lot of us who think it’s pretty important to have a native fish.
“We feel it’s important to bring the native cutthroat to as many waters as possible,” Skillen said. “We need a viable population so they don’t end up on the endangered list.
“We don’t want the federal government telling us how to run our fisheries,” he said.
The U.S. Forest Service, which built the stream barrier at Hotel Draw, is scheduled to build two more – one on the east fork of Hermosa Creek west of a waterfall, the other below the confluence of the Hermosa Creek main stem and the east fork.
Rotenone will be applied in those sections for two consecutive years to prepare them for stocking of the native cutthroat trout.
Three trout subspecies, including the Colorado River cutthroat, were cut off in what became Colorado by glacial activity eons ago.
In pre-Columbian times, the Colorado River variety was found in all cool-water habitat above present-day Glen Canyon.
The situation changed in the 1850s with the Western migration that brought settlers and miners to the region. Overconsumption of fish, the introduction of non-native species and degradation of water quality brought the number of native fish to levels that resulted in petitions from environmental groups to list the species as threatened or endangered.
Biologists reacted in 1990. They located pure strains of the native cutthroat trout in streams with an impassible barrier on the lower end and no lake at the top of the drainage.
Collecting eggs and milt from the pure strains, they built populations of the fish in hatcheries.