Recipient Organization
UNIVERSITY OF MONTANA
COLLEGE OF FORESTRY AND CONSERVATION
MISSOULA,MT 59812
Performing Department
College of Forestry and Conservation
Non Technical Summary
Westslope cutthroat trout Oncorhynchus clarkii lewsi (WCT) is a native trout in Lake Coeur d Alene, Idaho. Historically, Lake Coeur d' Alene and its tributaries supported robust populations of WCT that exhibited resident, fluvial (river-migrating), and adfluvial (lake-migrating) life histories. Rainbow trout O. mykiss (RBT) are an introduced trout species that interbreed or hybridize with WCT in most habitats where they are sympatric. As part of WCT conservation efforts, the Coeur d' Alene Tribe Department of Natural Resources Fisheries Program needs to develop a baseline of information for the population genetic structure of Lake Coeur d' Alene WCT populations. Such a baseline should include information regarding the genetic relationships among putative population groupings, as well as the distribution and quantification of historic RBT interbreeding with WCT. Tribal fisheries biologists will collect non-lethal tissue samples from Wolf Lodge Creek, Lake Creek, and Benewah Creek watersheds to be submitted to the Montana Conservation Genetics Laboratory for analyses. We will describe the cutthroat trout population genetic structure within and among Wolf Lodge Creek, Lake Creek, and Benewah Creek watersheds. This will allow us to describe the distribution and extent of introgressive hybridization within Wolf Lodge Creek, Lake Creek, and Benewah Creek watersheds. This study will provide the necessary data for the tribe to find and conserve key areas for the conservation of pure westslope cutthroat trout
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
Westslope cutthroat trout Oncorhynchus clarkii lewsi (WCT) is a native trout in Lake Coeur d Alene, Idaho. Historically, Lake Coeur d' Alene and its tributaries supported robust populations of WCT that exhibited resident, fluvial (river-migrating), and adfluvial (lake-migrating) life histories. Rainbow trout O. mykiss (RBT) are an introduced trout species that hybridize with WCT in most habitats where they are sympatric. As part of WCT conservation efforts, the Coeur d' Alene Tribe Department of Natural Resources Fisheries Program needs to develop a baseline of information for the population genetic structure of Lake Coeur d' Alene WCT populations. Such a baseline should include information regarding the genetic relationships among putative population groupings, as well as the distribution and quantification of introgressive hybridization with RBT. Tribal fisheries biologists will collect non-lethal tissue samples from Wolf Lodge Creek, Lake Creek, and Benewah Creek watersheds to be submitted to the Montana Conservation Genetics Laboratory for analyses to complete the following objectives: 1, Describe the cutthroat trout population genetic structure within and among Wolf Lodge Creek, Lake Creek, and Benewah Creek watersheds; and 2, Describe the distribution and extent of introgressive hybridization within Wolf Lodge Creek, Lake Creek, and Benewah Creek watersheds. May to September, 2009: Coeur d' Alene Tribe Department of Natural Resources Fisheries Program researchers collect tissue samples from Lake, Benewah, and Wolf Lodge creeks. September, 2009 to January, 2010: DNA extraction and amplification of polymorphic and diagnostic microsatellite markers: Process 30 samples from each of 4 tributaries in Lake Creek for a total of 120 samples; Process 30 samples from each of 6 tributaries in Benewah Creek for a total of 180 samples; Process 30 samples from each of 5 tributaries in Wolf Lodge Creek for a total of 150 samples. January to September, 2010: Complete analyses of genetic data and prepare a report of findings. Report that will include descriptions of the fine-scale population genetic structure and distribution of hybrid trout within and among Wolf Lodge Creek, Lake Creek, and Benewah Creek watersheds.
Project Methods
Coeur d' Alene Tribe Department of Natural Resources Fisheries Program researchers have identified three major watersheds that are tributaries to Lake Coeur d' Alene where they are going to collect non-lethal tissue samples from trout aggregations that may include WCT, RBT, and their Hybrids: Wolf Lodge Creek, Lake Creek, and Benewah Creek. Samples (n ≈ 30-35) will be gathered from putative population groupings at 4 - 5 sample locations in each of the three watersheds. Tissue will be sent to the Montana Conservation Genetics Laboratory (MCGL) at the University of Montana, Missoula, where DNA will be extracted and amplified using Polymerase Chain Reaction at multiple polymorphic microsatellite loci, of which several are diagnostic for hybridization between WCT and RBT. Researchers will conduct several tests for significant population structure, including tests for Hardy-Weinberg equilibrium, linkage equilibrium, allele frequency divergence, and population subdivision (Fst). Researchers will also calculate hybrid index scores for each individual fish assayed and complete tests to determine if population samples were collected from population groupings where introgression between WCT and RBT has led to total admixture (a hybrid swarm).