This article was downloaded by: [Montana State University Bozeman] On: 03 October 2011, At: 09:48 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Transactions of the American Fisheries Society Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/utaf20 Geomorphic Influences on the Distribution of Yellowstone Cutthroat Trout in the Absaroka Mountains, Wyoming Carter G. Kruse a , Wayne A. Hubert a & Frank J. Rahel b a U.S. Geological Survey Wyoming Cooperative Fish and Wildlife Research Unit, University of Wyoming, Laramie, Wyoming, 82071, USA b Department of Zoology and Physiology, University of Wyoming, Larande, Wyoming, 82071, USA Available online: 09 Jan 2011 To cite this article: Carter G. Kruse, Wayne A. Hubert & Frank J. Rahel (1997): Geomorphic Influences on the Distribution of Yellowstone Cutthroat Trout in the Absaroka Mountains, Wyoming, Transactions of the American Fisheries Society, 126:3, 418-427 To link to this article: http:// dx.doi.org/10.1577/1548-8659(1997)126<0418:GIOTDO>2.3.CO;2 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.tandfonline.com/page/terms-and- conditions This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Downloaded by [Montana State University Bozeman] at 09:48 03 October 2011 Transactions of the American Fisheries Society 126:418-427, 1997 €> Copyright by the American Fisheries Society 1997 Geomorphic Influence Distributioe th n o s f o n Yellowstone Cutthroat Trout in the Absaroka Mountains, Wyoming CARTER G. KRUSE AND WAYNE A. HUBERT U.S. Geological Survey, Wyoming Cooperative FishWildlifeand Research Unit1 University Wyoming.of Laramie. Wyoming 82071.USA FRANK J. RAHEL Department of Zoology and Physiology, University of Wyoming Laramie, Wyoming 82071, USA Abstract.—Influences of large-scale abiotic, geomorphic characteristics on distributions of Yel- lowstone cutthroat trout Oncorhynchus clarki bouvieri arc poorly understood samplee W . d 151 perennia6 5 site n o s l stream thn i se Greybull-Wood river drainag northwestern ei n Wyomino gt determin effecte eth geomorphif so c variable Yellowslonn so e cutthroat trout distributions. Channel slope, elevation, stream size, and barriers to upstream movement significantly influenced the presenc absencd an e f Yellowstono e e cutthroat trout. Wild population f Yellowstonso e cutthroat trout were not found upstream of barriers to fish migration, at sites with channel slopes of 10% or greater, or at elevations above 3,182 m. Based on channel slope alone, logistic regression models correctly classified presence or absence of Yellowstone cutthroat trout in 83% of study sites. The addition of elevation and stream size in the models increased classification to 87%. Logistic models tested on an independent data set had agreement rates as high as 91% between actual and predicted fish presence. Large-scale geomorphic variables influence Yellowstone cutthroat trout distributions, and logistic functions can predict these distributions with a high degree of accuracy. Yellowstone cutthroat trout Oncorhynchus clarki well 1995). Hanzel (1959), Behnke and Zarn bouvieri inhabit a larger geographic range than any (1976), Scarnecchi d Bergersean a n (1986)d an , other cutthroat trout subspecies except coastal cut- Varley and Gresswell (1988) noted that most ge- throat trout O. c. clarki (Varley and Gresswell netically pure population f Yellowstono s e cut- 1988). As in other interior stocks of cutthroat trout, throat trout occur in high-elevation headwaters in hybridization (Leary et al. 1984; Campion and Ut- remote areas. Additionally, Behnke (1992) sug- ter 1985; Gresswell 1995) and competition with geste e cutthroath d t trouy hav ma a teselectiv e exotic fishes (Griffith 1988; Young 1995) s wela , l advantage over nonnative trout in these areas be- as anthropogenic influences (logging, mining, ag- cause y thefunctioma y n bette coln i r d environ- riculture, irrigation; Hanzel 1959; Allendorf and ments. Leary 1988; Thuro . 1988al t we ; Gresswell 1995), Persistence of fish species in a stream system is have reduced the distribution of Yellowstone cut- influence abilite fise successfullth o th h t y f db yo y throat trou 70-90y b t % since settlemen Eury b t - use the habitat for cover, to acquire food, to in- opeans (Hadley 1984; Varle Gressweld yan l 1988; teract with othe e communityr th fisn i ho t d an , Behnke 1992; Young 1995). reproduce (Bozek and Hubert 1992). Constraints Downloaded by [Montana State University Bozeman] at 09:48 03 October 2011 Decline n Yellowstoni s e cutthroat trout distri- imposed by physical habitat can limit species per- butions have been most sever high-ordern i e , low- sistence; thus, identification of the abiotic factors elevation streams where human impacts are great- that limit species distribution s importanti s . Cat- est (Hanzel 1959; Gresswell 1988; Young 1995). astrophic events (Lamberti et al. 1991) and fish Limited acces remoteo st , high-elevation drainages migration barriers (Stube . 1988al t e r; Riemad nan and public ownership of most of these systems Mclntyre 1993) can have major impacts on fish have contribute protectioo dt f Yellowstonno e cut- surviva distributionsd an l . throat trout population theid an s r habitats (Gress- Habitat features that characterize trout distri- butions and abundance have been a common focus of research (e.g., Fausc . 1988al t he ; Nelso. al t ne e Uni jointlTh 1s i t y supporte e Universitth y b d f yo Wyoming, Wyoming Gam Fisd an eh Department, U.S. 1992; Riema d Mclntyrnan e 1995) s YellowA . - Department of the Interior, and Wildlife Management stone cutthroat trout populations continue to de- Institute. cline s imperativi t i , e that fishery manager- un s 418 GEOMORPHIC INFLUENCES ON TROUT DISTRIBUTION 419 derstand the environmental processes that control with high channel slopes, unstable substrates, and the habitat and, ultimately, fish populations in ar- large fluctuation dischargn i s e from sprin lato gt e eas where native fish still persist. Until recently, summer (Hanse Gloved nan r 1973). Elevationf so biologists have attempte characterizo dt e habitats streams in the study area range from 2,300 to 3,250 through traditional, small-scale approaches such as m above mean sea level. Channel slopes range stream reac r habitaho t unit inventories (Rieman fro mwit % 0.5 meah25 a %o t f 8.5% no , whics hi and Mclntyre 1995). But, as Nelson et al. (1992) generally considered steep (Kondol . 1991al t e f; and Rieman and Mclntyre (1995) pointed out, it Rosgen 1994). Snowmelt dominate annuae sth - hy l may be more important to understand trout distri- drograp d resultan h n extremeli s y high spring butio responsd nan habitao et t base spatialla n do y flows (Hanse d Glovean n r 1973; Martner 1982; large-scale, geomorphic approach. ZaffAnnead an t r 1992). Wetted stream widtf o h Trout habitat has been linked to large-scale geo- mainstreae th m Greybull River during late summer morphic variables (Lank . 1987al t ae ; Huberd an t glaciae varieth t a ls m headwaterfro 5 m3. 5 2 o t s Kozel 1993). Several researchers have shown that m at the Shoshone National Forest boundary with measures of elevation, channel slope, and stream most tributary streams ranging 2.5- widthn i 5m . size are useful indicators of trout occurrence The volcanicly derived watershed (Keefer 1972) (Platts 1979; Lanka et al. 1987; Kozel and Hubert is steep and rugged with uplifted peaks and deep 1989; Nelso . 1992al t ne ; Riema d Mclntyran n e valleys, resulting in mountain streams that have 1995). Incidence functions, base thesn do e types steep longitudinal profiles and low biological pro- of variables, that predict presence or absence of ductivity. Stream substrates and banks are pre- trout populations can be useful tools, particularly dominately erodible volcanic material (Hansen in areas where little detailed habitat or population Gloved an r 1973; ZaffAnnead an t r 1992), which, information is available (Rieman and Mclntyre coupled with high spring flow steed an s p channel 1995). slopes, result in channels that shift regularly (Kent Although generalized distribution f Yellowo s - 1984), are strewn with large angular rocks, are stone cutthroat trou Wyominn i t e knowngar - ac , poorly defined d providan , e limited fish habitat. curate description f theio s r specific locatione ar s e GreybulTh l River, historic Yellowstone cut- not available. Several areas have been identified throat trout range s currentli , y managee th y b d e Wyominbth y g Gam d Fisan eh Departmens a t Wyoming Game and Fish Department as a native having high potentia contaio t l n remnant, geneti- sport fishery for cutthroat trout. Mountain white- cally pure Yellowstone cutthroat trout populations, including the Greybull-Wood river drainage in fish Prosopium williamsoni, mountain suckers Ca- northwestern Wyoming. tostomus platyrhynchus, longnose dace Rhinicthys e purposTh f thieo sdetermino t stud s ywa e eth cataractae, and brook trout Salvelinus fontinalis distribution of Yellowstone cutthroat trout in the are also present in the drainage (Yekel 1980).