Water Resources Research Act Program

Details for Project ID 2007MT156B

Student Fellowship: Population Genetics and Distribution of Bull Trout Salvelinus confluentus Inhabiting Lakes within Glacier National Park, Montana

Institute: Montana
Year Established: 2007 Start Date: 2007-03-01 End Date: 2008-02-28
Total Federal Funds: $2,400 Total Non-Federal Funds: Not available

Principal Investigators: Michael Meeuwig

Project Summary: The bull trout Salvelinus confluentus is a species of charr endemic to western North America. Declining trends in bull trout populations throughout their native range has prompted increased interest in, and designation of this species as threatened under the US Endangered Species Act in 1998. Glacier National Park (GNP), Montana, contains some of the last, relatively unperturbed lake habitat available to adfluvial bull trout in their native range. This area has great potential for maintaining source populations important to the Columbia River Basin. However, recent research (Fredenberg 2002; M. H. Meeuwig, MT Cooperative Fishery Research Unit, unpublished data) has identified dramatic declines of bull trout over the last 30 years in the four largest lakes within GNP (Lake McDonald, Kintla Lake, Bowman Lake, and Logging Lake). These declines are associated with corresponding increases in numbers of invasive lake trout Salvelinus namaycush (Fredenberg 2002) that have colonized these waters from downstream sources since their introduction into the Flathead River system in 1905 (Spencer et al. 1991). The declining trend of bull trout following the introduction of lake trout is indicative of a population-level response to the addition of a potential resource competitor (Mathews 1998). Additionally, best available science indicates that conversion of native bull trout ecosystems to lake trout-dominated systems is a common result once lake trout become established (Donald and Alger 1993), and extirpation of bull trout from some of these lakes may occur in the near future (Fredenberg 2002). Therefore, understanding the migratory potential of bull trout among lakes in GNP is critical to determining the potential for population persistence. For example, migration of bull trout among lakes within GNP may supplement populations depressed by invasive lake trout and mediate problems associated with small populations (e.g., random genetic drift; Hallerman 2003). Additionally, understanding factors affecting movement within this networked group of lakes will provide insight into the susceptibility of the remaining non-invaded lakes to future lake trout invasions and may identify unique bull trout populations that warrant special protection. Protection of bull trout resources in GNP is a US Fish and Wildlife Service priority and major cooperators for this project include the US Geological Survey, the US Fish and Wildlife Service, and The US National Park Service. These cooperators have provided support in the form of funding for laboratory analysis and in-kind services. Through this cooperative effort much of the field work for this project has been completed with future work needed for laboratory analyses.