DURANGO - A major initiative by the Colorado Division of Wildlife to restore the native Colorado River cutthroat trout to the San Juan mountains will begin this summer in the upper Hermosa Creek drainage about 35 miles north of Durango.
The three-year project is a cooperative effort of the Division of Wildlife and the U.S. Forest Service, and part of a larger multi-state and agency effort to restore Colorado River cutthroat trout to more of its historic range.
Colorado River cutthroat are native to the Colorado River Basin.
The project will be explained to the public at an open house from 4-8 p.m., July 13, at the Durango Recreation Centers Windom Room.
Upper Hermosa Creek offers an excellent location for a native trout recovery project, said Jim White, aquatic biologist for the Division in Durango. The area is a big, complex network of tributaries and a main stem river with excellent water quality and trout habitat. The limestone geology is favorable for trout and the area is easily accessible to field crews and anglers.
Wildlife biologists identified the Hermosa Creek area as a prime spot for restoration about 20 years ago. In 1992, a similar project restored native cutthroats on four miles of the creeks upper East Fork.
This summers project will begin the process to reclaim about nine miles of Hermosa Creek at its headwaters. This phase is expected to take two years to complete, White said. The next phase will connect the main stem of Upper Hermosa Creek to the East Fork of Hermosa Creek. All in all, the full project is expected to last three to five years. When completed, Colorado River cutthroat trout will inhabit more than 20 miles of the Hermosa Creek drainage
Colorado River cutthroat trout currently occupy only a small portion of their historic range. Over-harvest, decline in water quality and the introduction of non-native trout starting in the 1850s nearly wiped out the native fish. Fortunately, Division biologists found remnant populations in Colorado, established brood stocks, and the species is now sustained through habitat protection, hatcheries, and stocking. The goal of the Divisions native trout program is to create sustainable wild populations of cutthroat trout to provide for the long-term survival of the species.
The Colorado River cutthroat trout is listed as a state species of concern; environmental groups have petitioned for it to be listed under the federal Endangered Species Act. The Division hopes that successful restoration programs will eliminate any need to consider listing the fish.
Eliminating non-native fish from Upper Hermosa Creek is the first step of the process. The Forest Service constructed a waterfall barrier on the creek near Hotel Draw last summer that will prevent non-native fish from swimming upstream into the newly reclaimed habitat. In early August, water above the barrier will be treated with Rotenone, a chemical derived from a tropical plant root which is also commonly used as an organic insecticide for roses. Rotenone, an EPA-registered pesticide, will kill the existing fish, mostly brook trout. The chemical is fast-acting, only affects aquatic species, leaves no residue and degrades quickly. Rotenone has been used for decades in fisheries management throughout North America and poses no threat to human health.
Before the treatment, the Division of Wildlife will capture some of the fish in the creek and move them to spots below the treatment area.
Because upper Hermosa Creek comprises a complex system, the water will be treated again in the summer of 2012 to assure that non-native fish are no longer present. This section of the creek will be restocked with native cutthroats in late summer 2012.
The project will result in a temporary loss of fishing opportunity. Plenty of places to fish, however, are available below the barrier and in other nearby waters.
In the third year of the project, another barrier will be built at the confluence of Hermosa Creek and East Hermosa Creek to allow for chemical treatment on the final section. Two years of treatment also will be required for this reach. Restocking with native trout is expected to occur there in late summer of 2014.
Another restoration project is planned for the Woods Lake area in San Miguel County on the north slope of the San Juan mountains this summer
Both areas will accommodate large numbers of fish. These metapopulations provide defense against disease outbreaks and other threats, such as wild fires, that can quickly wipe out small populations.
While we truly regret the inconvenience to anglers, we want to remind folks that these measures are necessary to maintain Colorados native trout, White said. There are many miles of streams in this area to fish including the East Fork of Hermosa Creek and below Hotel Draw. And in a couple of years, people will be able to fish for native cutthroats in all these creeks.
For more information, contact White at j.white@state.co.us, or (970)375-6712.
To learn more about fisheries management in Colorado, see: http://wildlife.state.co.us/Fishing.