Wigwam River McNeil Substrate Sampling Program : 1998-2002 Summary Report.

Abstract

The Wigwam River is an important fisheries stream in the East Kootenay region of British Columbia that supports healthy populations of both bull trout (Salvelinus confluentus) and Westslope cutthroat trout (Oncorhynchus clarki lewisi). The river has been characterized as the single most important bull trout spawning steam in the Kootenay Region (Baxter and Westover 2000), and thus has been the focus of numerous studies in the last ten years (Cope 1998; Cope and Morris 2001; Cope, Morris and Bisset 2002; Kohn Crippen Consultants Ltd. 1998; Westover 1999a; Westover 1999b; Westover and Conroy 1997). Although bull trout populations in the East Kootenay region remain healthy, bull trout populations in other parts of British Columbia and within their traditional range in northwestern United States have declined. Thus, bull trout were blue listed as vulnerable in British Columbia by the B.C. Conservation Data Centre (Cannings 1993) and remain a species of special concern. Bull trout in the north-western United States, within the Columbia River watershed, were listed as threatened in 1998 under the Endangered Species Act by the U.S. Fish and Wildlife Service. In 1999, the Ministry of Water, Land and Air Protection applied and received funding from the Bonneville Power Administration (BPA) to assess and monitor the status of wild, native stocks of bull trout in tributaries to Lake Koocanusa (Libby Reservoir) and the upper Kootenay River. The purpose of this report is to summarize one of the many studies undertaken to ''Monitor and Protect Bull Trout for Koocanusa Reservoir'' (BPA Project Number 2000-04-00). Three permanent sampling sites were established on the Wigwam River in April 1998. At each site, substrate samples were obtained using a McNeil Core sampler in April of each year from 1998 to 2002. The objectives of this study were to assess the quality of stream-bed substrates used by bull trout for spawning prior to major resource development in the Wigwam watershed, thus providing one potential measure of future impact to bull trout spawning habitat.