CHRISTOPHER GUY

Bio

Education

  • Ph.D. South Dakota State University, 1993
  • M.S. South Dakota State University, 1990
  • B.S. University of Missouri-Columbia, 1987

Summary

Most of my research falls within the broad mission of ecology of fishery and aquatic resources. A major, consistent research theme has been on native fish assemblage restoration, a prominent ecological and societal issue in Rocky Mountain and Great Plains ecosystems. Research interests include: fish ecology, fishery stock assessment, fishery management regulations and tools, native and non-native species interactions.

Professional Society Service

  • Co-editor, 2nd edition, Analysis and Interpretation of Freshwater Fisheries Data (2019- )
  • President, Education Section of the American Fisheries Society, 2003-2005
  • President, North Central Division of the American Fisheries Society, 2002-2003
  • President, Kansas Chapter of the American Fisheries Society, 1997-1998
  • Secretary-Treasurer, Fisheries Management Section, American Fisheries Society, 1996-1997
  • Chair, Steering Committee, Midwest Fisheries Conference, 2002
  • Chair, Communications Committee, Kansas Chapter of the American Fisheries Society, 2000-2002
  • Chair, Professionalism Committee, American Fisheries Society, 1998-1999
  • Chair, Skinner Award Committee, Education Section, American Fisheries Society, 1998-2002
  • Chair and moderator, Small Impoundment Symposium, 58th Midwest Fish and Wildlife Conference, 1996
  • Chair, Publications Awards Committee, American Fisheries Society, 1995-1997
  • Chair, Audiovisual Committee for the 1992 Annual Meeting of the American Fisheries Society, Rapid City, South Dakota, 1992
  • Co-chair, Contributed Papers Session, Western Division of the American Fisheries Society Annual Meeting, 2005-2006
  • Co-chair, Continuing Education Committee, Kansas Chapter of the American Fisheries Society, 1995-2002
  • Co-chair, Walleye Technical Committee, North Central Division, Walleye Sampling Survey Committee, 1994-1996
  • Member, World Sturgeon Conservation Society, 2009-2012
  • Member, American Institute of Biological Sciences, 2004-2010
  • Member, Montana Chapter American Fisheries Society, 2003-present
  • Member, Topeka Shiner Recovery Plan, Advisory Committee, 2002
  • Member, Membership Committee, American Fisheries Society, 2002
  • Member, Management Committee, American Fisheries Society, 2001-2003
  • Member, Meritorious Award Committee, American Fisheries Society, 1999-2000
  • Member, Skinner Award Committee, Education Section, American Fisheries Society, 1997-1998
  • Member, Student Paper Awards Committee, Education Section, American Fisheries Society, 1994-1995
  • Member, American Institute of Fishery Research Biologists, 1994-1997
  • Member, Kansas Chapter, American Fisheries Society, 1994-2002
  • Member, Publications Overview Committee, American Fisheries Society, 1992-1996
  • Member, Education Section, American Fisheries Society, 1991-present
  • Member, Fisheries Management Section, American Fisheries Society, 1989-present
  • Member, American Fisheries Society, 1986-present

Education & Research Statement

I am currently the Assistant Unit Leader (AUL) of the Montana Cooperative Fishery Research Unit (MTCFRU) and conduct research within the broad context of fish ecology and fisheries management. A consistent research theme of mine has been on native fish assemblage restoration, a prominent ecological and societal issue within the USA and globally. Within that theme, my research has two areas of emphasis—conservation of large-river fishes and suppression of invasive species (for conservation of native fishes).

These areas encompass a broad diversity in ecosystem types and fish assemblages—from large warm-water rivers to alpine lakes. Given the mission of the Cooperative Research Units program, I willingly assist natural resource agencies with their research needs. As a faculty member at Montana State University, I serve on university committees, teach graduate courses and seminars, and guest lecture in a variety of graduate and undergraduate courses.

Research

Quantify and prioritize lake trout spawning habitat for suppression

Duration: August 2020 – December 2023

Yellowstone Lake has been the site of intensive efforts to conserve native Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri and restore natural ecological function since invasive Lake Trout Salvelinus namaycush were first discovered there in 1994. Gillnetting was implemented in 1995 to suppress the Lake Trout population, but despite annual increases in gillnetting effort, the population expanded throughout Yellowstone Lake and increased in abundance until 2012, when the effort became large enough to curtail population growth. The Lake Trout population of Yellowstone Lake is highly resilient to gillnetting, probably because of high early life history survival. Interstitial embryo predators, which are a common source of embryo mortality in the native range of Lake Trout, do not inhabit Yellowstone Lake. Because Lake Trout population growth rates are most sensitive to changes in age-0 survival, alternative methods are being developed to reduce prerecruit survival, with an overall goal of increasing suppression efficiency while reducing long-term costs.

Quantifying Brown Trout and Lake Trout predation on Burbot and Mountain Whitefish

Duration: July 2019 – June 2023

Purpose and Need: Burbot and Mountain Whitefish are important native sportfish species in Wyoming, with Burbot classified as a Species of Greatest Conservation Need (ranked as Native Species Status 3; WGFD 2017). Additionally, Underwood et al. (2015) revealed that genetic differentiation exists among Wind River tributary drainage Burbot stocks. Thus, the Torrey Creek drainage Burbot stock that occurs in Torrey Creek and Trail, Ring, and Torrey lakes is a high conservation priority (Figure 1). Managers have been concerned with the declines in Ring Lake Burbot since the 1990s. Burbot catch rate was higher in Ring Lake than four other Wind River drainage lakes from 1967 to 1969, and six other drainage lakes from 1995 to 1996 (Miller 1970a, 1970b; Krueger and Hubert 1997). Conversely, Ring Lake Burbot catch rate in trammel nets was lower than six of seven other drainage lakes from 2007 to 2008 and lowest among six drainage lakes from 2011 to 2013 (Abrahamse 2009; Lewandoski 2015).

Enhancing survival and condition of first feeding larval pallid sturgeon through diet

Duration: April 2019 – December 2022

Summary Conservation propagation facilities in the Upper Basin are currently experiencing variable survival of first feeding larval Pallid Sturgeon. This type of hatchery-induced “selection” can ultimately have unintended, negative consequences on genetic representation of Pallid Sturgeon returned to the Missouri and Yellowstone Rivers, and managers are now investigating potential sources of mortality in the hatchery. Larval mortality is high at 19-21 days (at 16-18°C) and occurs as a result of starvation. This study seeks to determine if survival and condition of first feeding larval Pallid Sturgeon and successful weaning to a formulated diet can be enhanced by a diet more similar to dietary options in the wild. The results of this study can be used to develop a feeding regimen to enhance survival and condition of larval Pallid Sturgeon in conservation propagation facilities. Problem Statement and Background Conservation propagation is defined as the production of individuals for reintroduction in the wild, and is a critical component of recovery plans for aquatic species at risk of extinction or population loss (Paragamian and Beamesderfer 2004; Caroffino et al. 2008; George et al. 2009; Lorenzen et al. 2010). Conservation propagation has been used to successfully augment populations of multiple imperiled fishes, like Chinook Salmon Oncorhynchus tshawytscha (Fast et al. 2015), and continues at present to be the main source of production of larval Pallid Sturgeon Scaphirhynchus albus in the Upper Missouri River Basin (Steffensen et al. 2010).

Quantifying spawning locations and habitat use by adult lake trout in Swan Lake, Montana

Duration: February 2018 – October 2022

Novel experimental approaches to suppressing lake trout have focused on the early-life stages because lake trout spawning behavior and the physiology of lake trout embryos provide an opportunity for embryo suppression with limited bycatch. Spawning lake trout congregate on rocky shoals broadcasting gametes over angular clean cobble substrate (Binder et al. 2014), and demonstrate spawning site fidelity (Esteve et al. 2008). Lake trout embryos are non-motile and have undeveloped physiological systems with a limited ability to acclimate to environmental perturbations (Pörtner and Farrell 2008; Helvik et al. 2009). Increasing mortality beyond gillnetting and in lieu of gillnetting (the most preferred option) is probably feasible because of the vulnerability of lake trout embryos.

Spawning Characteristics and an Assessment of Juvenile Sampling Methods and Habitat for Mountain Whitefish in the Green River, Wyoming

Duration: July 2018 – June 2022

Mountain whitefish Prosopium williamsoni are widely distributed throughout western North America, including many streams and lakes in the western Wyoming (Scott and Crossman 1973; Baxter and Stone 1995). Mountain whitefish are an important ecological and recreational component of streams and lakes in Wyoming, such as the upper Green River. Historically, mountain whitefish were likely one of the most abundant sport fishes in the Intermountain West, including states such as Montana (Brown 1952) and Wyoming. Mountain whitefish prey on a variety of aquatic taxa and terrestrial insects (Brown 1971; Pontius and Parker 1973; Scott and Crossman 1973). Therefore, mountain whitefish often compose a large portion of the biomass present within streams and lakes and likely contribute substantially to ecosystem processes (e.g., nutrient cycling). Additionally, mountain whitefish contribute to the diets of avian predators such as osprey (Van Daele and Van Daele 1982) and terrestrial predators such as river otters (Melquist and Hornocker 1983) and mink.

Bull Trout Emigration Study

Duration: May 2018 – December 2021

Currently, we have a limited and potentially biased understanding of when juvenile Bull Trout emigrate from the Montana adfluvial streams. This understanding is limited to inferences based on the literature (i.e., what has been documented in other systems), preliminary information from direct tributaries to Lake Pend Oreille, and the timing of fish captured in traps in the Montana adfluvial streams. The literature suggests that juvenile Bull Trout emigration timing can be variable, potentially system specific, and potentially influenced by numerous factors. Of particular interest, numerous adfluvial Bull Trout populations exhibit a large spring emigration associated with the freshet and peak flows. The closest and most well-documented evidence for this comes from Trestle Creek which is a direct tributary to Lake Pend Oreille. Downs et al. (2006) documented substantial spring emigration events in Trestle Creek that have never been observed in the Montana adfluvial streams; albeit, the spring events were predominated by age-0 emigrants which purportedly have survival rates approaching zero.

Using Carcass and Carcass-Analog Material to Increase Lake Trout

Duration: September 2019 – December 2021

Invasive species introductions cause negative economic effects and disrupt natural ecosystem interactions, with the potential of inducing ecological impairment or ecosystem collapse (Elton 1958; Vitousek 1996; Sala et al. 2000). Invasive species introduction and expansion is the second greatest threat to global biodiversity decline next to habitat degradation (Wilcove 1998; WWF 2016). Additionally, such introductions are recognized as a major threat to aquatic ecosystems (Ricciardi 1999; Pimentel et al. 2005). Invasive species disrupt ecosystems by displacing and reducing native species populations (Vitousek et al. 1996), usually through competition, predation, or both (Cucherousset and Olden 2011). Invasive species have the ability to initiate trophic cascades through the alteration of ecosystem food-web dynamics (Eby et al. 2006).

Lake trout population modeling and annual assessment of suppression netting

Duration: September 2016 – August 2021

Invasive species introductions cause reductions in populations of native species and are associated with negative environmental and economic effects. Suppression techniques including chemical, mechanical, and biological controls are commonly used to manage invasive species. Understanding the ecosystem-level influence of suppression techniques selected by natural resource agencies is essential for establishment of successful mitigation against invasive species and assisting native populations in an altered ecosystem. Invasive Lake Trout within Yellowstone Lake, Yellowstone National Park, Wyoming have greatly reduced the abundance of native Yellowstone Cutthroat Trout and disrupted the ecosystem through food-web alteration.

Reproductive indices of hatchery-origin white sturgeon in the lower Columbia River, Canada

Duration: August 2017 – June 2020

Recruitment of White Sturgeon in the Transboundary Recovery Area (TRA) of the Columbia River [Hugh L. Keenleyside Dam (HLK) to Grand Coulee Dam (GCD) in WA, USA] has not occurred at a rate sufficient over the past 40 years to maintain the population going forward. Conservation aquaculture has become a critical component of recovery programs, including for White Sturgeon (Acipenser transmontanus) in the lower Columbia River where extirpation has largely been avoided due to the success of hatchery-origin juveniles released into the wild. Survival of hatchery-origin juveniles in the upper Columbia River population has been higher than originally predicted, with more than 30,000 individuals estimated to be at large in the population (BC Hydro 2016a).

Spawning readiness, spawning location(s), and habitat use of pallid sturgeon in the Missouri River above Fort Peck Reservoir, Montana

Duration: September 2017 – June 2020

This project will estimate spawning readiness of hatchery-reared and wild pallid sturgeon, identify spawning location(s), and habitat characteristics at spawning location(s). This information is central to the management of pallid sturgeon in the upper Missouri River given the current understanding of drift distance, anoxic conditions in transition zone above Ft. Peck Reservoir (Guy et al. 2015), and the high occurrence of atresia in pallid sturgeon as identified in a recent study. A better understanding of the factors outlined above will provide useful information for water-level management in the river and downstream reservoir.

Mobile tracking of lake trout on Yellowstone Lake

Duration: September 2015 – August 2019

Invasive Lake Trout were first discovered in Yellowstone Lake in 1994. The population quickly grew decimating the native Yellowstone Cutthroat Trout population. Removal efforts of Lake Trout began shortly after the discovery of Lake Trout and has grown into a multi-million dollar operation. Park Service and contract gillnetting crews have removed over 1.7 million Lake Trout from Yellowstone Lake. Original efforts focused on younger smaller Lake Trout. In recent years, the effort to remove larger mature Lake Trout has intensified. Targeting known spawning ground has proven to be a successful strategy for removing large quantities of mature fish.

Preliminary analysis of paddlefish data from the Missouri River above Ft. Peck Reservoir with a focus on population abundance and survival

Duration: June 2018 – June 2019

The paddlefish (Polyodon spathula) fisheries in Montana are important recreational fisheries that are highly valued by Montana Fish, Wildlife & Parks and anglers within and outside Montana. Given the life-history characteristics of paddlefish such as long-lived and late maturing, managing the species for sustainable harvest requires precise and accurate information about their population dynamics because they are particularly susceptible to overharvest (Boreman 1997). Population vital-rate data are essential to developing harvest models and in turn those models are used by fisheries biologists to establish harvest regulations that ensure sustainable harvest. Without the understanding from model outputs, fisheries biologists could be allowing the population to be over-harvested or under-harvested (i.e., denying angling opportunities).

Lake Roosevelt burbot maturation study

Duration: December 2016 – January 2019

Sexual dimorphism in Burbot, Lota lota, can be difficult to discern as the species is seemingly monomorphic (Cott et al., 2013). Burbot spawn over a relatively short time frame (Arndt and Hutchinson, 2000; McPhail and Paragamian, 2000) indicating that the species has synchronous gonadal development. Reliable information regarding gametogenesis is required for population status assessment and harvest modeling. The objectives of this proposed work are to:

  1. Describe gametogenesis and the endocrine profile in adult Lake Roosevelt Burbot.
  2. Develop non-invasive (ultrasound) and less-invasive (plasma sex steroids) tools to determine sex and stage of maturity.
  3. Develop non-invasive (egg diameter via ultrasound) and non-lethal invasive (collection of gametes through catheterization) tools to predict spawning readiness and successful spawning.

Annual Evaluation and Development of Benchmarks for Lake Trout Suppression in Yelowstone Lake

Duration: June 2013 – June 2018

The Native Fish Conservation Plan (National Park Service 2010) proposed a framework for conserving native fish in Yellowstone National Park from 2011-2031. An important component of the Native Fish Conservation Plan is to continue suppression of nonnative lake trout in Yellowstone Lake for the conservation benefit of native Yellowstone cutthroat trout. The National Park Service desires to restore Yellowstone cutthroat trout abundance to the level present at the early stages of lake trout invasion. Quantifiable goals for abundance of lake trout and Yellowstone cutthroat trout (see Methods) were defined in the Native Fish Conservation Plan.

Buffalo Bill Reservoir walleye suppression

Duration: July 2015 – June 2018

Buffalo Bill Reservoir (BBR) and the North Fork Shoshone River are two of the most popular fisheries in the Cody Region. These waters are managed as wild trout fisheries consisting of Yellowstone Cutthroat Trout (YSC), Rainbow Trout (RBT), Rainbow X Cutthroat hybrids (RXC), and few Brown Trout (BNT). Lake Trout (LAT), illegally introduced Walleye (WAE) and few Yellow Perch are also present in BBR. White and Longnose suckers are the primary components of the non-game fishery. Adult Rainbow and Yellowstone cutthroat trout migrate into the North Fork Shoshone River drainage in March through May spawn in tributaries and return to the reservoir in late summer. Migrant spawners range from 12 to 20 inches in length and from 4 to 9 years in age.

Evaluations of Methods to Introduce Mortality in Lake Trout Embryos

Duration: July 2014 – January 2018

Lake trout have been intentionally or inadvertently introduced into many lakes throughout the west (Martinez et al. 2009), and the establishment of non-native lake trout populations often causes declines in native species abundance. For example, introduced lake trout (Salvelinus namaycush) threaten to extirpate native Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) in Yellowstone Lake, Yellowstone National Park. Consequently, it was deemed that suppression of the lake trout was needed to conserve Yellowstone cutthroat trout in Yellowstone Lake. Gillnetting is the primary method used to suppress lake trout in Yellowstone Lake and this method has been used since the program began in 1995.

Density of Pallid Sturgeon and Food Web Dynamics in the Missouri River

Duration: January 2013 – December 2017

Our goal is to provide inferences regarding pallid sturgeon Scaphirhynchus albus carrying capacity, using two complementary methods (vital rates and production), in the Missouri River and Yellowstone River (i.e., RPMA 2). This information will be useful in guiding an adaptive conservation propagation program.

Enhancing native fisheries through the USFWS Propagation Program in Region 6

Duration: June 2015 – September 2017

The goal of this project is to align our R6 production hatcheries with national priorities establishing conservation propagation facilities that assist with landscape conservation and state partnership needs. The specific objectives are to:

  1. Develop a decision-support tool to identify and prioritize conservation propagation for threatened, endangered, imperiled and declining species
  2. Work in conjunction with our state partners to coordinate and balance recovery and restoration efforts with recreational fishing opportunities. The identified priority species will be linked with the most appropriate conservation propagation facilities in R6.

Environmental and endogenous factors affecting egg quality and caviar yield in farmed sturgeon

Duration: June 2011 – July 2017

Several families in select year classes of the captive broodstock of the endangered pallid sturgeon are experiencing high levels of accumulation of gonadal fat which impairs reproductive performance. Sturgeon farmers in California and Idaho also observe highly variable roe yield in mature sturgeon associated with accumulation of fat in the ovaries. Environmental, genetic and developmental factors can all affect gonadal fat accumulation, but as of yet the role of these factors is not well understood. Understanding these effects is essential for conservation propagation of endangered sturgeons and sustained production of high quality sturgeon caviar.

Reproductive readiness and behavioral ecology of wild hatchery-reared pallid sturgeon in the Missouri River above Fort Peck Reservoir, Montana

Duration: January 2014 – June 2017

Determine the age at sexual differentiation, age at first maturity, and spawning periodicity of wild hatchery-reared pallid sturgeon in the Missouri River. In addition, this project will replicate the research conducted by Gerrity et al. (2006, 2008) to determine if temporal changes have occurred in home range size and habitat use within the 1997 year class of pallid sturgeon. That is, has the 1997 year class become sexually mature and do they have similar home range size and habitat use as Gerrity et al. (2008) observed in 2003 (age 6) and 2004 (age 7)?

Determining Ripeness in White Sturgeon Females to Maximize Yield and Quality of Caviar

Duration: August 2007 – March 2017

The long-term goal of this study is to improve product quality and increase economic efficiency of caviar production. The specific objectives are:

  1. Determine the effect of dietary energy on ovarian adiposity and the roe yield in early (7 yr) and late (8 yr) maturing females.
  2. Determine dietary and farm effects on the physical, chemical, and sensory properties of sturgeon caviar.
  3. Characterize the effect of genotype on egg yield and ovarian adiposity in early and late maturing females and in early ontogeny of sturgeon (age 3 years).
  4. Develop an integrated approach for management of farmed sturgeon with high caviar yield and product quality as outreach for the project.

Evaluation of juvenile bull trout outmigration in Thompson Falls Reservoir

Duration: November 2013 – December 2016

Bull trout are listed as a threatened species by the US Fish and Wildlife Service, and in the lower Clark Fork River the species is impacted by three main-stem impoundments (Thompson Falls,Noxon, and Cabinet Gorge reservoirs). Dams and reservoirs significantly alter natural habitats (physical and biological) and influence upstream and downstream fish movement. An understanding od juvenile bull trout use and movement through impoundments is necessary to identify how these altered habitats and dam operation can impact downstream migrating juvenile bull trout and accordingly the status of associated populations.

Electroshocking to Induce Mortality of Lake Trout Embryos in Yellowstone Lake

Duration: July 2013 – June 2015

The intent of this project is to refine and test a benthic oriented electrode array for reducing survival of lake trout embryos. The electrode array will be developed and lab tested in the spring and early summer. In situ experiments will be conducted in the autumn of 2013. This project will supplement an ongoing Montana State University project to develop an identical electrode array for the same purpose in Swan Lake, Montana. The funding outlined below would support expansion of the Swan Lake project to include similar methodologies in Yellowstone Lake.

Spawning Characteristics and Early Life History of Mountain Whitefish in the Madison River, Montana

Duration: January 2012 – June 2015

Despite the putative abundance of mountain whitefish in Montana water bodies (Brown 1952) and their availability as a sport fish (Brown 1971; Scott and Crossman 1973), relatively little is known about the ecology of mountain whitefish in Montana. Fish population monitoring programs in Montana are generally not designed to target mountain whitefish; therefore, available data are difficult to decipher and potentially unreliable for identifying long-term trends (Mountain Whitefish Summit 2009). However, at least some mountain whitefish populations in Montana are showing signs of decline (Mountain Whitefish Summit 2009). In the Madison River drainage, mountain whitefish numbers have declined in Hebgen Lake since the early 2000s (Mountain Whitefish Summit 2009), but trend data are not available for the Madison River.

Diet and temperature effects on growth of pallid and shovelnose sturgeon

Duration: June 2012 – September 2014

The goal of this study is to assess latitudinal variation in growth rates of pallid sturgeon and shovelnose sturgeon and determine how those rates are affected by diet and temperature. This study consists of multiple objectives that will provide information that can be used by managers to aid conservation and restoration of pallid sturgeon and shovelnose sturgeon as well as serve as an indicator of the effects of climate change on two federally protected riverine fish species.

Students

Current Students

  • Kelson Hickman (M.S.)
  • Max Rubino (Ph.D.)
  • Michael Lant (Ph.D.)
  • Tori Ogolin (M.S.)
  • Hannah Stapleton (M.S.)
  • Cody Vender (M.S.)
  • Katie Furey (M.S.)
  • Drew MacDonald (M.S.)
  • Michelle Briggs (Ph.D.)

Previous Students

  • Robert Eckelbecker (Ph.D. 2024)
  • Hayley Glassic (Ph.D. 2022)
  • Mike Siemiantkowski (M.S. 2021)
  • Colter Brown (M.S. 2021)
  • Madeline Lewis (M.S. 2021)
  • Tanner Cox (M.S. 2020)
  • Paige Maskill (M.S. 2020)*
  • Daniel Kaus (M.S. 2019)
  • Lauren McGarvey (M.S. 2019)*
  • Jacob Williams (M.S. 2019)
  • Adeline Dutton (M.S. 2018)
  • Jeffrey Glaid (M.S. 2017)
  • Luke Holmquist (M.S. 2017)*
  • Austin McCullough (M.S. 2017)
  • Nathan Thomas (M.S. 2017)
  • Jan Boyer (M.S. 2016)
  • Sean Lewandoski (M.S. 2015)
  • John Syslo (M.S. 2010; Ph.D. 2015)
  • Carter Fredenberg (M.S. 2014)
  • Benjamin Galloway (M.S. 2014)
  • Ryan Richards (M.S. 2011)
  • Benjamin Cox (M.S. 2010)
  • Mariah Talbott (M.S. 2010)*
  • Lora Tennant (M.S. 2010)
  • Benjamin Goodman (M.S. 2009)
  • Michael Meeuwig (Ph.D. 2008)
  • James Boyd (M.S. 2008)
  • Jason Mullen (M.S. 2007)
  • Eric Oldenburg (M.S. 2008)
  • Kiza Gates (M.S. 2007)
  • Melissa Wuellner (M.S. 2007)
  • Brian Bellgraph (M.S. 2006)
  • Andy Dux (M.S. 2005)
  • Paul Gerrity (M.S. 2005)
  • Nathan Olson (M.S. 2004)

Previous Students at Kansas State University

  • Stan Proboszcz (M.S. 2003)
  • Michael Quist (M.S. 1998; Ph.D. 2002)
  • Sally Schrank (M.S. 2000)
  • Travis Horton (M.S. 2000)
  • Jeffry Tripe (M.S. 2000)
  • Patrick Braaten (Ph.D. 2000)
  • Matthew Burlingame (M.S. 1997)
  • Jeff Tillma (M.S. 1997)
  • Jennifer Wiens (M.S. 1996)

*co-advised with Dr. Molly Webb

Publications

Glassic, H. C., J. R. Junker, C. S. Guy, D. R. Lujanm, L. M. Tronstad, M. A. Briggs, L. K. Albertson, T. O. Brenden, T. Walsworth, and T. M. Koel. 2024. An invasive predator substantially alters energy flux without changing food web functional state or stability. Aquatic Conservation: Marine and Freshwater Ecosystems https://doi.org/10.1002/aqc.4240 – PDF HERE

Briggs, M. A., H. C. Glassic, C. S. Guy, S. T. Opitz, J. J. Rotella, D. A. Schmetterling. 2024. Adapting standardized trout monitoring to a changing climate for the upper Yellowstone River, Montana, USA. North American Journal of Fisheries Management https://doi.org/10.1002/nafm.11026 – PDF HERE

Treanor, H. B., C. S. Guy, J. E. Ilgen, W. M. Sealey, A. T. Dove, and M. A. H. Webb. 2024. Survival and growth of larval pallid sturgeon are improved by a live diet. North American Journal of Aquaculture. http://doi.org/10.1002/naaq.10340

Lujan, D. R., L. M. Tronstad, M. A. Briggs, L. K. Albertson, JH. C. Glassic, C. S. Guy, and T. M. Koel. 2024. Novel technique for suppressing an invasive apex predator minimally alters nitrogen dynamics in Yellowstone Lake, Wyoming, USA. Hydrobiologia. https://doi.org/10.1007/s10750-023-05450-w

Glassic, H. C., D. D. Chagris, C. S. Guy, L. M. Tronstad, D. R. Lujan, M. A. Briggs, L. K. Albertson, T. O. Brenden, T. E. Walsworth, and T. M. Koel. 2023. Yellowstone Cutthroat Trout recovery in Yellowstone Lake: complex interactions among invasive species suppression, disease, and climate change. Fisheries. PDF HERE

Scholl, E. A., W. F. Cross, C. S. Guy, A. J. Dutton, and J. R. Junker. 2023. Landscape diversity promotes stable food-web architectures in large rivers. Ecology Letters. https://doi.org/10.1111/ele.14289 – PDF HERE

Glassic, H. C., C. S. Guy, L. M. Tronstad, M. A. Briggs, L. K. Albertson, D. R. Lujan, and T. M. Koel. 2023. Decomposition rates of suppression-produced fish carcasses in a large, deep, high-elevation lake in North America. Fishes. https://doi.org/10.3390/fishes8080385 – PDF HERE

Cox, T. L., C. S. Guy, L. M. Holmquist, and M. A. H. Webb. 2023. Spawning locations of pallid sturgeon in the Missouri River corroborate the mechanisms for recruitment failure. Fishes. https://doi.org/10.3390/fishes8050243 – PDF HERE

Galat, D. L., P. Braaten, C. S. Guy, T. Horton, D. Moser, C. Pukert. 2023. Missouri River. Pages 411– 453 in M. Delong, T. Jardine, A. Benke, and C. Cushing, editors.  Rivers of North America. Elsevier, Oxford. ISBN: 9780128188477 PDF HERE

Koel, T. M., P. D. Doepke, D. J. MacDonald, N. A. Thomas, C. W. Vender, H. C. Glassic, A. S. Poole, C. S. Guy, and A. V. Zale. 2023. Aerial application of organic pellets eliminates lake trout recruitment from a primary spawning reef in Yellowstone Lake. North American Journal of Fisheries Management. https://doi.org/10.1002/nafm.10872 – PDF HERE

Glassic, H. C., C. S. Guy, D. R. Lujan, L. M. Tronstad, M. A. Briggs, L. K. Albertson, T. M. Koel. 2023. Diet plasticity in an invasive predator has implications for native species conservation & invasive species suppression. PLOS ONE. https://doi.org/10.1371/journal.pone.0279099 – PDF HERE

Eckelbecker, R. W., N. M. Heili, C. S. Guy, and D. A. Schmetterling. 2023. Relative-condition parameters for fishes of Montana, USA. Fishes. https://doi.org/10.3390/fishes8010028 – PDF HERE

Siemiantkowski, M. J., C. S. Guy, T. M. Koel, L. M. Tronstad, C. R. Fredenberg, and L. R. Rosenthal. 2022. Combination of acoustic telemetry and side-scan sonar advances suppression efforts for invasive lake trout in a submontane lake. North American Journal of Fisheries Management. https://doi.org/10.1002/nafm.10855 PDF HERE

McGarvey, L. M., J. E. Ilgen, C. S. Guy, J. G. McLellan, and M. A. H. Webb. 2022. Non-lethal tools to identify mass ovarian follicular atresia in Burbot.Journal of Fish and Wildlife Management. https://doi.org/10.3996/JFWM-22-018 PDF HERE

Lewis, M. C., C. S. Guy, E. W. Oldenburg, and T. E. McMahon. 2022. Individual characteristics and abiotic factors influence out-migration dynamics of juvenile bull trout. Fishes. https://doi.org/10.3390/fishes7060331. PDF HERE

Lewis, M. C., C. S. Guy, E. W. Oldenberg, T. E. McMahon. 2022. Temporal variation in capture efficiency underrepresents spring out-migrating Bull Trout in a trap-and-haul program. North American Journal of Fisheries Management 42:1237-1249. https://doi.org/10.1002/nafm.10817 PDF HERE

Klein, Z. B., M. C. Quist, and C. S. Guy. 2022. Suppression of invasive fish in the west: synthesis and suggestions for improvement. North American Journal of Fisheries Management. https://doi.org/10.1002/nafm.10827 PDF HERE

Briggs, M. A., L. K. Albertson, D. R. Lujan, L. M. Tronstad, H. C. Glassic, C. S. Guy, and T. M. Koel.  2022.  Fish carcass deposition to suppress invasive lake through hypoxia causes limited, non-targeted effects on benthic invertebrates in Yellowstone Lake. Aquaculture, Fish, and Fisheries.https://doi.org/10.1002/aff2.72 PDF HERE

Scholl, E. A., W. F. Cross, and C. S. Guy. 2022. Connecting geomorphology, biodiversity, and ecosystem function in large riverscapes. Okios. https://doi.org/10.1111/oik.09431 PDF HERE

Cox, T. L., C. S. Guy, L. M. Holmquist, and M. A. H. Webb. 2022. Reproductive indices and observations of mass ovarian follicular atresia in hatchery-origin pallid sturgeon. Journal of Applied Ichthyology 38:391–402. https://doi.org/10.1111/jai.14339 PDF HERE

Lujan, D. R., L. M. Tronstad, M. A. Briggs, L. K. Albertson, H. C. Glassic, C. S. Guy, and T. M. Koel.  2022.  Response of nutrient limitation to invasive fish suppression: how carcasses and analog pellets alter periphyton. Freshwater Science 41:88-99. https://www.journals.uchicago.edu/doi/10.1086/718647 PDF HERE

Williams, J. R., C. S. Guy, P. E. Bigelow, and T. M. Koel. 2021.  Quantifying the spatial structure of invasive lake trout (Salvelinus namaycush) in Yellowstone Lake to improve suppression efficacy. North American Journal of Fisheries Management. PDF HERE

Maskill, P. A. C., J. A. Crossman, M. A. H. Webb, M. M. Carrello, and C. S. Guy. 2021.  Accuracy of histology, endoscopy, ultrasound, and plasma sex steroids in describing the reproductive sturgeon of hatchery-origin and wild white sturgeon. Journal of Applied Ichthyology https://onlinelibrary.wiley.com/doi/10.1111/jai.14280 PDF HERE

Glassic, H. C., C. S. Guy, and T. M. Koel. 2021. Diets and stable isotope signatures of native and nonnative Leucisid fishes advances our understanding of the Yellowstone Lake food web. Fishes https://doi.org/10.3390/fishes6040051 PDF HERE

McGarvey, L. M., J. E. Ilgen, C. S. Guy, J. G. McLellan, and M. A. H. Webb. 2021. Gonad size measured by ultrasound to assign stage of maturity in burbot. Journal of Fish and Wildlife Management 12:241-249. PDF HERE

Glaid, J., P. C. Gerrity, and C. S. Guy. 2021. Burbot (Lota lota) exhibit plasticity in life-history traits in a small drainage at the southwestern-most extent of the species’ native range. Journal of Applied Ichthyology. https://onlinelibrary.wiley.com/doi/abs/10.1111/jai.14243 PDF HERE

Guy, C. S., T. L. Cox, J. R. Williams, C. D. Brown, R. W. Eckelbecker, H. S. Glassic, M. C. Lewis, P. A. C. Maskill, L. M. McGarvey, and M. J. Siemiantkowski. 2021. A paradoxical knowledge gap in science for critically endangered fishes and game fishes during the sixth mass extinction. Scientific Reports 11:8447. https://doi.org/10.1038/s41598-021-87871-y PDF HERE

Hansen, M. J., C. S. Guy, C. R. Bronte, and N. A. Nate.  2021.  Life history and population dynamics.  Pages 253-286 in A. M. Muir, C. C. Krueger, M. J. Hansen, and S. C. Riley, editors.  Lake Charr Salvelinus namaycush: biology, ecology, distribution, and management.  Fish & Fisheries Series, D. L. G. Noakes, editor.  Springer.

Briggs, M. A., L. K. Alberston, D. R. Lujan, L. M. Tronstad, H. C. Glassic, C. S. Guy, and T. M. Koel. 2021. Carcass deposition to suppress invasive lake trout causes differential mortality of two common benthic invertebrates in Yellowstone Lake. Fundamental and Applied Limnology 194:285-295. https://doi.org/10.1127/fal/2020/1352

Driscoll, S. C., H. C. Glassic, C. S. Guy, and T. M. Koel. 2021. Presence of microplastics in the food web of the largest high-elevation lake in North America. Water. 13, 264. https://doi.org/10.3390/w13030264

Scholl, E. A., W. F. Cross, C. V. Baxter, and C. S. Guy. 2020. Uncovering process domains in large rivers: Patterns and potential drivers of benthic substrate heterogeneity in two North American riverscapes. Geomorphology https://doi.org/10.1016/j.geomorph.2020.107524

Furey, K. M., H. C. Glassic, C. S. Guy, T. M. Koel, J. L. Arnold, P. D. Doepke, and P. E. Bigelow. 2020. Diets of longnose sucker in Yellowstone Lake, Yellowstone National Park, U.S.A. Journal of Freshwater Ecology https://doi.org/10.1080/02705060.2020.1807421

Glassic, H. C., C. S. Guy, J. J. Rotella, C. J. Nagel, D. A. Schmetterling and S. R. Dalbey. 2020. Fort Peck paddlefish population survival and abundance in the Missouri River. Journal of Applied Ichthyology 36:559-567. https://doi.org/10.1111/jai.14067 PDF HERE

Scholl, E. A., W. F. Cross, C. V. Baxter, and C. S. Guy.  2020.  Uncovering process domains in large rivers: Patterns and potential drivers of benthic substrate heterogeneity in two North American riverscapes. Geomorphology. https://doi.org/10.1016/j.geomorph.2020.107524

Koel, T. M., J. L. Arnold, P. E. Bigelow, T. O. Brenden, J. D. Davis, C. R. Detjens, P. D. Doepke, B. D. Ertel, H. C. Glassic, R. E. Gresswell, C. S. Guy, D. J. MacDonald, M. E. Ruhl, T. J. Stuth, D. P. Sweet, J. M. Syslo, N. A. Thomas, L. M. Tronstad, P. J. White, and A. V. Zale. 2020. Yellowstone Lake ecosystem restoration: a case study for invasive fish management. Fishes. https://doi.org/10.3390/fishes5020018

Syslo, J. M., T. O. Brenden, C. S. Guy, T. M. Koel, P. E. Bigelow, P. D. Doepke, J. L. Arnold, and B. E. Ertel.  2020.  Could ecological release buffer suppression efforts for non-native lake trout (Salvelinus namaycush) in Yellowstone Lake, Yellowstone National Park? Canadian Journal of Fisheries and Aquatic Sciences 77:1010-1025. PDF HERE

Furey, K. M., H. C. Glassic, C. S. Guy, T. M. Koel, J. L. Arnold, P. D. Doepke, and P. E. Bigelow. 2020. Diets of longnose sucker in Yellowstone Lake, Yellowstone National Park, USA. Journal of Freshwater Ecology. https://doi.org/10.108/02705060.2020.1807421 PDF HERE

McGarvey, L. M., L. J. Halvorson, J. E. Ilgen, C. S. Guy, J. G. McLellan, and M. A. H. Webb.  2020.  Gametogenesis and assessment of non-lethal tools to assign sex and reproductive condition in burbot Lota lota.  Transactions of the American Fisheries Society 149:225-240. PDF HERE

Williams, J. R., C. S. Guy, T. M. Koel, P. Bigelow.  2020.  Targeting aggregations of telemetered lake trout to increase gillnetting suppression efficacy.  North American Journal of Fisheries Management 40:225-231. PDF HERE

Glassic, H. C., K. C. Heim, and C. S. Guy.  2019.  Creating figures in R that meet the AFS style guide: standardization and supporting script.  Fisheries 44:539-544. (Top 10% of most downloaded papers between January 2018 and December 2019) PDF HERE

Boyer, J. K., C. S. Guy, M. A. H. Webb, T. B. Horton, and T. E. McMahon.  2017.  Reproductive ecology, spawning behavior, and juvenile distribution of mountain whitefish in the Madison River, Montana.  Transactions of the American Fisheries Society 146:939-954. PDF HERE

Lewandoski, S. A., C. S. Guy, A. V. Zale, P. C. Gerrity, J. W. Deromdei, K. M. Johnson, D. L. Skates.  2017.  Empirical estimation of recreational exploitation of burbot, Lota lota, in the Wind River drainage of Wyoming using a multistate capture-recapture model.  Fisheries Management and Ecology 24:298-307. PDF HERE

Brown, P. J., C. S. Guy, and M. H. Meeuwig.  2017.  A comparison of two mobile electrode arrays for increasing mortality of Lake Trout.  North American Journal of Fisheries Management 37:363-369. PDF HERE

Fredenberg, C. R., C. C. Muhlfeld, C. S. Guy, V. S. D’Angelo, C. C. Downs, and J. M. Syslo.  2017.  Suppression of invasive lake trout in an isolated backcountry lake in Glacier National Park.  Fisheries Management and Ecology 24:33-48. PDF HERE

Boyer, J. K., C. S. Guy, M. A. H. Webb, T. B. Horton, and T. E. McMahon.  2017.  Gear comparison for sampling age-0 mountain whitefish in the Madison River, Montana.  North American Journal of Fisheries Management 37:189-195. PDF HERE

Galloway, B. T., C. C. Muhlfeld, C. S. Guy, C. C. Downs, and W. A. Fredenberg.  2016.  A framework for assessing the feasibility of native fish conservation translocations: applications to threatened bull trout.  North American Journal of Fisheries Management 36:754-768. PDF HERE

Syslo, J. M., C. S. Guy, and T. M. Koel.  2016.  Feeding ecology of native and nonnative salmonids during the expansion of a nonnative apex predator in Yellowstone Lake, Yellowstone National Park.  Transactions of the American Fisheries Society 145:476-492.  PDF HERE

Tennant, L. B., R. E. Gresswell, C. S. Guy, and M. H. Meeuwig.  2015.  Spawning and rearing behavior of bull trout in a headwater lake ecosystem.  Environmental Biology of Fishes DOI 10.1007/s10641-015-0461-x.  PDF HERE

Guy, C.S., H. B. Treanor, K. M. Kappenman, E. A. Scholl, J. E. Ilgen, and M. A. H. Webb. 2015. Broadening the regulated-river management paradigm: a case study of the forgotten dead zone hindering pallid sturgeon recovery. Fisheries 40:7-14.  PDF HERE

Richards, R. R., C. S. Guy, M .A. H. Webb, W. M. Gardner, and C. B. Jensen. 2014. Spawning related migration of shovelnose sturgeon in the Missouri River above Fort Peck Reservoir, Montana. Journal of Applied Ichthyology 30:1-13.  PDF HERE

Wuellner, M. R., R. G. Bramblett, C. S. Guy, A. V. Zale, D. R. Roberts, and J. Johnson. 2013. Reach and catchment-scale characteristics are relatively uninfluential in explaining the occurrence of stream fish species. Journal of Fish Biology 82:1497-1513.  PDF HERE

Syslo, J. M., C. S. Guy, and B. S. Cox. 2013. Comparison of harvest scenarios for the cost-effective suppression of lake trout in Swan Lake, Montana. North American Journal of Fisheries Management 33:1079-1090. PDF HERE

Cox, B. S., C. S. Guy, W. A. Fredenberg, and L. R. Rosenthal. 2013. Baseline demographics of a non-native lake trout population and inferences for suppression from sensitivity-elasticity analyses. Fisheries Management and Ecology. Fisheries Management and Ecology 20:390-400. PDF HERE

Goodman, B. J., C. S. Guy, S. L. Camp, W. M. Gardner, K. M. Kappenman, and M. A. H. Webb. 2013. Shovelnose sturgeon spawning in relation to varying discharge treatments in a Missouri River tributary. River Research and Applications 29:1004-1015.  PDF HERE

Neumann, R. M., C. S. Guy, and D. W. Willis. 2012. Length, weight, and associated indices. Pages 637-676 in A.V. Zale, D. L. Parrish, and T. M. Sutton, editors. Fisheries techniques, 3rd edition. American Fisheries Society, Bethesda, Maryland.

Ferguson, J. M., M. L. Taper, C. S. Guy, and J. M. Syslo. 2012. Mechanisms of coexistence between native bull trout (Salvelinus confluentus) and non-native lake trout (Salvelinus namaycush): inferences from pattern-oriented modeling. Canadian Journal of Fisheries and Aquatic Sciences 69:755-769. PDF HERE

Cox, B. S., A. M. Dux, M. C. Quist, and C. S. Guy. 2012. Use of seismic air gun to reduce survival of non-native lake trout embryos: a tool for conservation? North American Journal of Fisheries Management 32:292-298. PDF HERE

Russell, R. E., D. A. Schmetterling, C. S. Guy, B. B. Shepard, R. McFarland, and D. Skaar. 2012. Evaluating a fish monitoring protocol using state-space hierarchical models. Open Fish Science Journal 5:1-8. PDF HERE

Syslo, J. M., C. S. Guy, P. E. Bigelow, P. D. Doepke, B. D. Ertel, and T. M. Koel. 2011. Response of non-native lake trout (Salvelinus namaycush) to 15 years of harvest in Yellowstone Lake, Yellowstone National Park. Canadian Journal of Fisheries and Aquatic Sciences 68:2132-2145. PDF HERE

Guy, C. S., McMahon, T. E., W. A. Fredenberg, C. J. Smith, D. W. Garfield, and B. S. Cox. 2011. Diet overlap of top-level predators in recent sympatry: bull trout and non-native lake trout in Swan Lake, Montana. Journal of Fish and Wildlife Management 2:183-189. PDF HERE

Dux, A. M., C. S. Guy, and W. A. Fredenberg. 2011. Spatiotemporal distribution and population characteristics of a nonnative lake trout population, with implications for suppression. North American Journal of Fisheries Management 31:187-196.PDF HERE

Mullen, J. A., R. G. Bramblett, C. S. Guy, and A. V. Zale. 2011. Determinants of fish assemblage structure in northwestern Great Plains streams. Transactions of the American Fisheries Society 140:271-281. PDF HERE

Meeuwig, M. H., C. S. Guy, and W. A. Fredenberg. 2011. Use of cover habitat by bull trout, Salvelinus confluentus, and lake trout, Salvelinus namaycush, in a laboratory environment. Environmental Biology of Fishes 90:367-378. PDF HERE

Guy, C. S. 2011. Review of: Biology, management, and conservation of lampreys in North America. The Quarterly Review of Biology 86:62.

Meeuwig, M. H., C. S. Guy, and W. A. Fredenberg. 2011. Trophic relationships between a native and nonnative predator in a system of natural lakes. Ecology of Freshwater Fish 20:315-325. PDF HERE

Oldenburg, E. W., C. S. Guy, E. S. Cureton, M. A. H. Webb, and W. M. Gardner. 2011. Effects of acclimation on poststocking dispersal and physiological condition of age-1 pallid sturgeon. Journal of Applied Ichthyology 27:436-443. PDF HERE

Talbott, M. J., J. P. Van Eenennaam, J. Linares-Casenave, S. I. Doroshov, C. S. Guy, P. Struffenegger, M. A. H. Webb. 2011. Investigating the use of plasma testosterone and estradiol-17β to detect ovarian follicular atresia in farmed white sturgeon, Acipenser transmontanus. Aquaculture 315:283-289. PDF HERE

Courses

Fisheries Science (WILD 510)

(Taught in the spring semester of even years.)

Course Description:  

Advanced study of theory and techniques related to fisheries science. Emphasis will be placed on data analyses needed to support management practices.

Course Objectives:
  • To gain an understanding of sampling needs, structured decision-making, and adaptive management.
  • To better understand the dynamic rate functions (i.e., recruitment, growth, and mortality) and population dynamics of fish populations.
  • To establish an understanding of indices and associated assumptions commonly used in fisheries science.
  • To understand exploitation and harvest regulations.
  • To develop an understanding of predator-prey relationships in aquatic systems.
  • To apply ecological principles to answer questions in fisheries science.
  • To develop an appreciation for the interdependence of fisheries research and management.

Course materials are available on D2L.

Communications in Ecological Sciences (BIO 555)

(Taught in the spring semester.)

Course Description:

This course will allow students to gain experience presenting scientific information using a variety of communication methods.

Course Objectives:
  • Develop an understanding of the variety of communication methods used by scientists.
  • Gain experience in presenting scientific information in a variety of formats for both nonprofessional and professional audiences.
  • Provide an atmosphere that promotes collegiality among all sub-disciplines in the Department of Ecology.

Course materials are available on D2L.

Analysis and Interpretation of Freshwater Fisheries Data

You can purchase the book at: https://fisheries.org/shop/55049c

Dr. Derek H. Ogle has done a wonderful job of converting many of the box examples from SAS code to R script.  See his website at: https://derekogle.com/aiffd2007/

Contact

Christopher Guy

Assistant Unit Leader & Professor
USGS, Montana Cooperative Fishery Research Unit

Office Location

301 Lewis Hall, Department of Ecology
Montana State University – Bozeman

Mailing Address

Montana State University
PO Box 173460
Bozeman, MT 59717-3460

Details

Office: (406) 994-3491
Fax: (406) 994-7479
Email: cguy@montana.edu

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