| Investigating the Disappearance of the Westslope Cutthroat Trout from B.C. |
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| Investigators |
| Peter Corbett, RP Biol, Mirkwood Ecological Consultants Ltd.
Dr. Eric Taylor, Department of Zoology, University of British Columbia
Emily Rubidge (M.Sc. candidate), Department of Zoology, University of British Columbia
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What is the Issue? |
| GENETIC INVASION |
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The westslope cutthroat trout (Oncorhynchus clarki lewisi), the native salmonid of many of the forested streams of the interior Pacific Northwest, has all but been eliminated from most of its native territory due to the introduction of rainbow trout. One of the last strongholds of the westslope cutthroat trout is in the Upper Kootenay River basin of southeastern British Columbia. This study is conducting a genetic assessment of westslope cutthroat populations in several watersheds to assist with the implementation of a much needed conservation strategy.
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What is our goal? |
| CONSERVATION OF BIOLOGICAL DIVERSITY, MAINTENANCE OF A WORLD-CLASS WESTSLOPE CUTTROAT TROUT FISHERY.
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Where we currently stand. |
| Results have been completed for 7 of the 11 sample sites representing 5 of the 8 rivers assessed in the Upper Kootenay River watershed. Through DNA analysis, hybrid trout have been found in the St. Mary River, Skookumchuck River, Gold Creek, and the North Fork of the White River. Only the population in the Bull River, above the hydroelectric dam, has been identified as uncontaminated. It would appear that the disbursal of rainbow trout stocked in Koocanusa Reservoir is widespread throughout the historic range of the cutthroat trout, and that hybridization will occur wherever the rainbow trout have unrestricted access to the tributary spawning streams of the cutthroat trout. The intent of the second year of this study was to increase knowledge of the geographic distribution of hybridization throughout the basin. In addition, the researchers wanted to quantify the magnitude and rate of change of hybridization in the St. Mary's River and Gold Creek, in the hope that predictive calculations could be made indicating the length of time prior to the creation of a hybrid swarm. Eight hundred samples were collected from the St. Mary's River, 200 from Gold Creek and 30 samples from 10 new streams whose genetic populations were unknown. At present, the samples are being analyzed, and results should be ready by January, 2001. To assist with determining the distribution of hybridization, all of the data have been incorporated into a Geographic Information System (GIS), which will be available to all interested parties on a future web site.
This project is sponsored by the Moore Family Foundation.
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You can help this project - find out how. |
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