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An analysis of spatial and environmental factors influencing hybridization between native westslope cutthroat trout (Oncorhynchus clarki lewisi) and introduced rainbow trout (O. mykiss) in the upper Kootenay River drainage, British Columbia

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Abstract

Westslope cutthroat trout (Oncorhynchus clarki lewisi, WCT) and introduced rainbow trout (O. mykiss, RBT) readily hybridize and introgression has occurred in many drainages across the historic native range of WCT. In British Columbia (Canada), the upper Kootenay River drainage is the heart of the westslope cutthroat trout (WCT, Oncorhynchus clarki lewisi) distribution in Canada this drainage harbours native WCT gene pools that are thought to be under threat from hybridization with introduced rainbow trout (RBT, O. mykiss). In this study, we assess the extent and distribution of WCT × RBT hybridization in the upper Kootenay River drainage. We used four diagnostic nuclear loci to determine the extent of hybridization in 981 fish collected from 23 sample localities across 12 different streams in the upper Kootenay River drainage. About 14% (142/981) of individuals were identified as hybrids (an individual with both RBT and WCT alleles), 3.4% (33/981) were identified as pure RBT, and the remaining individuals were identified as pure WCT. Although pure RBT were absent from the majority of locales (20/23), we found evidence of hybridization at 78% (18/23) of the localities and the percentage of heterospecific alleles (% I) ranged from 0.7% to 97.1%. Only 22% (5/23) of the localities showed no evidence of hybridization. Spatial analysis showed clustering among hybridized locations and decreasing hybridization with increasing distance from Koocanusa Reservoir, suggesting that the reservoir acts as a RBT source. We found no evidence that stream order, stream magnitude, or stream elevation influenced the extent of hybridization among localities. We compared our results to an analysis conducted in 1986, which indicated that hybridization is relatively recent in the upper Kootenay River drainage and that it is increasing in magnitude and distribution. In the absence of timely management intervention, the genetic integrity of WCT populations in the heart of their Canadian range may be lost. Our results indicate the dynamic nature of hybridization in fluvial systems and that for closely related taxa such as WCT and RBT, hybridization appears to be largely influenced by physical barriers to dispersal and contact between species.

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References

  • SB Adams CA Frissell BE Rieman (2001) ArticleTitleGeography of invasion in mountain streams: Consequences of headwater lake fish introductions Ecosystems 4 296–307

    Google Scholar 

  • FW Allendorf RF Leary (1988) ArticleTitleConservation and distribution of genetic variation in a polytypic species, the cutthroat trout Conserv. Biol. 2 170–184

    Google Scholar 

  • FW Allendorf RF Leary NP Hitt KL Knudsen LL Lindquist P Spruell (2004) ArticleTitleIntercrosses and the U.S. Endangered Species Act: Should hybridized populations be included as westslope cutthroat trout Conserv. Biol. 18 IssueID5 1203–1213

    Google Scholar 

  • J Baker P Bentzen P Moran (2002) ArticleTitleMolecular markers distinguish coastal cutthroat trout from coastal rainbow trout/steelhead and their hybrids Trans. Am. Fish. Soc. 131 404–417

    Google Scholar 

  • WJ Boecklen DJ Howard (1997) ArticleTitleGenetic analysis of hybrid zones: numbers of markers and power of resolution Ecology 78 2611–2616

    Google Scholar 

  • MA Bozek FJ Rahel (1991) ArticleTitleAssessing habitat requirements of young Colorado River cutthroat trout by use of macrohabitat and microhabitat analyses Trans. Am. Fish. Soc. 120 571–581

    Google Scholar 

  • KH Brown SJ Patton KE Martin KM Nichols R Armstrong GH Thorgaard (2004) ArticleTitleGenetic analysis of interior Pacific Northwest Onchrohynchus mykiss reveals apparent ancient hybridization with westslope cutthroat trout Trans. Am. Fish. Soc. 133 1078–1088

    Google Scholar 

  • MN Bruton (1995) ArticleTitleHave fishes had their chips? The dilemma of threatened fishes Environ. Biol. Fishes 43 1–27

    Google Scholar 

  • CA Busack GAE Gall (1981) ArticleTitleIntrogressive hybridization in populations of Paiute cutthroat trout (Salmo clarki seleniris) Can. J. Fish. Aquat. Sci. 38 939–951

    Google Scholar 

  • MR Campbell J Dillon MS Powell (2002) ArticleTitleHybridization and introgression in a managed, native population of Yellowstone cutthroat trout: Genetic detection and management implications Trans. Am. Fish. Soc. 131 364–375

    Google Scholar 

  • DE Campton FM Utter (1985) ArticleTitleNatural hybridization between steelhead trout (Salmo gairdneri) and coastal cutthroat trout (S.clarki) in two Puget Sound streams Can. J. Fish. Aquat. Sci. 42 110–119

    Google Scholar 

  • GJ Carmichael JN Hanson ME Schmidt DC Morizot (1993) ArticleTitleIntrogression among Apache, cutthroat and rainbow trout in Arizona Trans. Am. Fish. Soc. 122 121–130

    Google Scholar 

  • Casgrain P, Legendre P (2001) The R Package for multivariate and spatial analysis, version 4.03 — User’s Manual. Departement des sciences biologiques, Universite de Montreal. www.fas.umontreal.ca/BIOL/legendre

  • Costello AB, Rubidge E (2004) Status review of cutthroat trout (Oncorhynchus clarki spp.) in Canada. Report for the Committee on the Status of Endangered Wildlife In Canada. Ottawa, Ontario

  • MF Docker A Dale DD Heath (2003) ArticleTitleErosion of interspecific reproductive barriers resulting from hatchery supplementation of rainbow trout sympatric with cutthroat trout Mol. Ecol. 12 3515–3521

    Google Scholar 

  • KD Fausch Y Taniguchi S Nakano GD Grossman CR Townsend (2001) ArticleTitleFlood disturbance regimes influence rainbow trout invasions success among five holarctic regions Ecol. Appl. 11 1438–1455

    Google Scholar 

  • GF Hartman CA Gill (1968) ArticleTitleDistributions of juvenile steelhead and cutthroat trout, Salmo gairdneri and S.clarki clarki within streams in Southwestern B.C. J. Fish. Res. Bd. Can. 25 33–48

    Google Scholar 

  • R Henderson JL Kershner CL Toline (2000) ArticleTitleTiming and location of spawning by nonnative wild rainbow trout and native cutthroat trout in the South Fork Snake River, Idaho, with implications for hybridization North Am. J. Fish. Manage. 20 584–596

    Google Scholar 

  • RH Hilderbrand JL Kershner (2000) ArticleTitleConserving inland cutthroat trout in small streams: How much stream is enough? North Am J. Fish. Manage. 20 513–520

    Google Scholar 

  • NP Hitt CA Frissell CC Muhlfeld FM Allendorf (2003) ArticleTitleSpread of hybridization between native westslope cutthroat trout, Oncorhynchus clarki clarki, and nonnative rainbow trout, Oncorhynchus mykiss Can. J. Fish. Aquat. Sci. 60 1440–1451

    Google Scholar 

  • Johnson OW, Ruckelshaus MH, Grant WS, Waknitz FW, Gharrett AM, Bryant GJ, Neely K, Hard JJ (1999) Status review of coastal cutthroat trout from Washington, Oregon and California. NOAA Tech. Mem. NMFS-NWFSC−37

  • N Kanda RF Leary P Spruell FW Allendorf (2002) ArticleTitleMolecular genetic markers identifying hybridization between the Colorado River-Greenback cutthroat trout complex and Yellowstone cutthroat trout or rainbow trout Trans. Am. Fish. Soc. 131 312–319

    Google Scholar 

  • RF Leary FW Allendorf SR Phelps KL Knudsen (1984) ArticleTitleIntrogression between westslope cutthroat and rainbow trout in the Clark Fork River drainage Proc. Montana Acad. Sci. 43 1–18

    Google Scholar 

  • RF Leary FW Allendorf KL Knudsen (1987a) ArticleTitleGenetic divergence among populations of westslope cutthroat trout in the upper Kootenay River drainage, British Columbia Populations Genetics Laboratory Report Univ. of Montana 87 1–17

    Google Scholar 

  • RF Leary FW Allendorf SR Phelps KL Knudsen (1987b) ArticleTitleGenetic divergence among seven species of cutthroat trout and rainbow trout Trans. Am. Fish. Soc. 116 580–587

    Google Scholar 

  • RF Leary FW Allendorf GK Sage (1995) ArticleTitleHybridization and introgression between introduced and native fish Am. Fish. Soc. Symp. 15 91–101

    Google Scholar 

  • GA Liknes PJ Graham (1988) ArticleTitleWestlope cutthroat trout in Montana: Life history, status and management Am. Fish. Soc. Symp. 4 53–60

    Google Scholar 

  • N Mantel (1967) ArticleTitleThe detection of disease clustering and a generalized regression approach Cancer Res. 27 209–220

    Google Scholar 

  • Mayhood DW, (1999) Provisional evaluation of the status of westslope cutthroat trout in Canada. In: Proceedings of the Biology and Management of Species and Habitats at Risk (ed. Darling LM), http://www.fwresearch.ab.ca/library, Kamloops, B.C

  • RR Miller JD Williams JE Williams (1989) ArticleTitleExtinctions of North American fishes during the past century Fisheries 14 22–38

    Google Scholar 

  • MG Mitro AV Zale (2002) ArticleTitleSeasonal survival, movement and habitat use of age−0 rainbow trout in the Henrys Fork of the Snake River, Idaho Trans. Am. Fish. Soc. 131 271–286

    Google Scholar 

  • C Ostberg J Rodriguez (2002) ArticleTitleNovel molecular markers differentiate between Oncorhynchus mykiss (rainbow trout and steelhead) and the O.clarki (cutthroat trout) subspecies Mol. Ecol. Notes 2 197–202

    Google Scholar 

  • AJ Paul JR Post (2001) ArticleTitleSpatial distribution of native and nonnative salmonids in streams of the eastern slopes of the Canadian Rocky Mountains Trans. Am. Fish. Soc. 130 417–430

    Google Scholar 

  • JM Rhymer D Simberloff (1996) ArticleTitleExtinction by hybridization and introgression Ann. Rev. Ecol. Syst. 27 83–109

    Google Scholar 

  • A Ricciardi JB Rasmussen (1999) ArticleTitleExtinction rates of North American freshwater fauna Conserv. Biol. 13 1220–1222

    Google Scholar 

  • Rubidge E ,(2003) Molecular Analysis of Hybridization between Native Westslope Cutthroat Trout (Oncorhynchus clarki lewisi) and Introduced Rainbow Trout (O. mykiss) in Southeastern British Columbia. MSc Thesis, University of British Columbia

  • Rubidge E, Taylor EB (2004) Hybrid zone structure and the potential role of selection in hybridizing populations of native westslope cutthroat trout (Oncorhynchus clarki lewisi) and introduced rainbow trout (O. mykiss). Mol. Ecol., 13, in press

  • E Rubidge P Corbett EB Taylor (2001) ArticleTitleA molecular analysis of hybridization between native westslope cutthroat trout and introduced rainbow trout in southeastern British Columbia, Canada J. Fish Biol. 59 42–54

    Google Scholar 

  • BB Shepard B Sanborn L Ulmer DD Lee (1997) ArticleTitleStatus and risk of extinction for westslope cutthroat trout in the Upper Missouri River Basin, Montana North Am. J. Fish. Manage. 17 1158–1172

    Google Scholar 

  • Shepard BB, May BE, Urie W (2002) Status of westslope cutthroat trout (Oncorhynchus clarki lewisi) in the United States: 2002. Montana Fish, Wildlife and Parks, Bozeman, MT

  • Taylor EB (2003) An analysis of homogenization and differentiation of Canadian freshwater fish faunas with an emphasis on British Columbia. Can. J. Fish. Aquat. Sci., 60, In press

  • EB Taylor (2004) Evolution in mixed company AP Hendry SC Stearns (Eds) Evolution Illuminated. Salmon and their Relatives Oxford University Press Oxford 232–263

    Google Scholar 

  • Tews A, Enk M, Hill W, Dalbey S, Liknes GA (2000) Westslope cutthroat trout (Oncorhychus clarki lewisi). In: North central Montana Status and Restoration Strategies. Special Report by Montana, Fish Wildlife and Parks in collaboration with Lewis and Clark National Forest

  • PC Trotter (1987) Cutthroat Native Trout of the West Colorado Associated University Press Boulder, Colorado

    Google Scholar 

  • FM Utter FW Allendorf (1994) ArticleTitlePhylogenetic relationships among species of Oncorhynchus: a consensus view Conserv. Biol. 8 864–867

    Google Scholar 

  • DE Weigel JT Peterson P Spruell (2002) ArticleTitleA model using phenotypic characters to detect introgressive hybridization in wild westslope cutthroat trout and rainbow trout Trans. Am. Fish. Soc. 131 389–403

    Google Scholar 

  • DE Weigel JT Peterson P Spruell (2003) ArticleTitleIntrogressive hybridization between native cutthroat trout and introduced rainbow trout Ecol. Appl. 13 38–50

    Google Scholar 

  • JE Williams RR Miller (1990) ArticleTitleConservation status of the North American fish fauna in fresh water J. Fish Biol. 37 79–85

    Google Scholar 

  • WP Young CO Ostberg P Keim GH Thorgaard (2001) ArticleTitleGenetic characterization of hybridization and introgression between anadromous rainbow trout (Oncorhynchus mykiss irideus) and coastal cutthroat trout (O.clarki clarki) Mol. Ecol. 10 921–930

    Google Scholar 

  • J. Zar (Eds) (1999) Biostatistical Analysis EditionNumber4th edn Prentice-Hall Inc Upper Saddle River, New Jersey, USA

    Google Scholar 

Download references

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Rubidge, E.M., Taylor, E. An analysis of spatial and environmental factors influencing hybridization between native westslope cutthroat trout (Oncorhynchus clarki lewisi) and introduced rainbow trout (O. mykiss) in the upper Kootenay River drainage, British Columbia. Conserv Genet 6, 369–384 (2005). https://doi.org/10.1007/s10592-005-4972-4

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