Refuge Management
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Fisheries Management
on Red Rock Lakes National Wildlife Refuge
Although many people think of Red Rock Lakes NWR as a swan refuge, we also manage for a variety of other creatures, including fish. There are 13 species of fish occurring on the Refuge. Game fish include arctic grayling, cutthroat trout, brook trout, and mountain whitefish. Other fish found on the Refuge include mottled sculpin and mountain sucker.
Native cutthroat trout, mountain whitefish, and arctic grayling can be found in Upper Red Rock Lake and Red Rock Creek. Suckers are also native and can be found in most of the Refuge waters. Mottled sculpin are often seen by people walking along Odell and Red Rock Creeks. Rainbow trout and brook trout were introduced to the valley as early as 1889 and can be found in Red Rock Creek.
Habitat
There are two basic habitat types important to fish on the Refuge. These are riverine and lacustrine. Riverine systems are creeks and rivers. Lacustrine systems are lakes and deep ponds. Some fish are restricted to creeks, like mottled sculpin. Others leave the lakes only to spawn, like arctic grayling.
All of the fish found on the Refuge are cold water fish. They require cold water to exist. This is because cold water holds more oxygen. When waters warm too much the fish suffocate. Low water levels, lack of shoreline vegetation and slow water can all lead to lakes, creeks, and rivers becoming warmer.
Erosion is also an important factor which affects fish. Although erosion is a natural process, it can be sped up by land uses or unusual weather. Sediments in the water can cover spawning gravels, smother eggs, and fill in lakes. Upper Red Rock Lake was at one time at least eighteen feet deep. Gradually it has been filling up with sediment, and now it is probably no more than ten feet deep at its deepest point. This may limit winter habitat available to fish. Causes of erosion include mining, excessive livestock grazing near streams, and heavy rains.
Management
Historically there has been little active management of fish on Refuge lands other than game fish stocking. Currently, the Refuge conducts population and habitat surveys and uses fencing to protect streamside vegetation from grazing. Other management is not active, but consists more of maintaining natural stream flows.
Past research on fisheries has been conducted in cooperation with Montana State University and the Bozeman Fish Technology Center. In recent years, the Refuge has been working on a project with the Montana Fish & Wildlife Management Assistance Office (FWMAO) in Bozeman, MT, to enhance the Refuge's arctic grayling and cutthroat trout fisheries. Extensive tagging and genetics studies on cutthroat trout and arctic grayling are planned. Tagging will be done to determine where fish spawn, how far they travel and what areas they use most. Also planned are aquatic and riparian habitat improvement efforts for the principle tributaries of Upper and Lower Red Rock Lakes (Red Rock Creek and Odell Creek, respectively). Cutthroat trout and arctic grayling, which currently inhabit these systems, are dependant upon Red Rock and Odell Creeks for spawning habitat and possibly rearing habitat for juveniles. However, considerable deterioration of these drainages has occurred over the last 30-40 years due to various activities including overgrazing of riparian vegetation by livestock and dewatering of the creeks.
The purpose of this project is to ensure the survival of the grayling and cutthroat populations by implementing stream habitat improvements to enhance, protect, and preserve these aquatic habitats. Specifically, management goals are to:
- preserve existing (remnant) arctic grayling population;
- determine the genetic strains of arctic grayling and cutthroat trout in the upper Centennial Valley;
- conduct fish population assessments in Red Rock and Odell Creeks and Upper and Lower Red Rock Lakes;
- place fish traps on Red Rock and Odell Creeks to evaluate the adult population and fry recruitment of the arctic grayling;
- minimize possible impediments to spawning runs and spawning;
- maintain minimum stream flow requirements for Odell and Red Rock Creeks;
- maintain fish screens on all water diversions in order to prevent fish from entering and becoming stranded in diversion ditches, and monitor diversion activity so that no water is diverted when fry are small enough to pass through screens;
- reduce sedimentation in Red Rock and Odell Creeks;
- monitor riparian and aquatic habitat so that degradation or improvements can be observed and appropriate actions can be implemented in a timely manner;
- identify essential spawning and over-winter habitat in both the Upper and Lower Lakes and Odell and Red Rock Creeks; and
- evaluate Refuge ponds for their potential to serve as arctic grayling rearing and/or production areas.
Endangered Species
Big Hole grayling have been proposed for listing under the Endangered Species Act. These fish are fluvial, meaning they spend their entire life in rivers and streams. The grayling at Red Rock Lakes NWR are thought to be adfluvial. This means that they spend most of their life in lakes or ponds and go into streams only to spawn. While Red Rock Lakes grayling are not candidates for listing, tagging studies will help confirm this.
Beaver and Fish
Beaver are also native to Centennial Valley. Pools created by beaver dams are very important winter habitat for fish in this area as well as providing habitat for birds and mammals. In years of low water, dams may interfere with fish movements. In order to maximize the benefits and eliminate detrimental effects, we manage our beaver dams, although our techniques are still evolving. Dams which interfere with fish movements even in years of normal water flow are removed in the spring. Dams which interfere only in very low water years are notched in those years to allow fish to move through.
History
Historically the waters of the Centennial Valley were thick with arctic grayling, cutthroat trout, and other fish. Now their numbers are fairly low, due mostly to historical land uses. Red Rock Lakes NWR is trying to restore our native fish to their past glory. In the meantime, please help us by practicing catch and release fishing on our native cutthroat trout and arctic grayling. Feel free to keep your limit of rainbow and brook trout.
Whirling Disease
Recently, some of the trout within the Centennial Valley, particularly Red Rock Creek, have been threatened by whirling disease. The Refuge is working with state and national agencies to help prevent and control this problem. For more information, visit the Whirling Disease Information section of the Fishing Information Webpage and consult the websites listed below.
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Websites Related to Fisheries Management
Whirling Disease Task Force, http://whirling-disease.org/
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