Christopher Guy, PhD
Assistant Unit Leader - Montana Cooperative Fishery Research Unit
Research Interests
- Fish ecology
- Fishery stock assessment
- Fishery management regulations and tools
- Native and non-native species interactions
Teaching Interests
- Fisheries Science
- Fisheries Techniques
Professional Experience
Assistant Unit Leader, Montana Cooperative Fishery Research Unit, 1994-
Education and Certifications
Ph D South Dakota State University 1993
Science and Products
Filter Total Items: 40
Could ecological release buffer suppression efforts for non-native lake trout (Salvelinus namaycush) in Yellowstone Lake, Yellowstone National Park?
Yellowstone Lake in Yellowstone National Park, USA, has the longest ongoing suppression program for non-native lake trout (Salvelinus namaycush) in the western USA. Harvest data from the suppression program, along with data from an assessment program initiated in 2011, was used to estimate lake trout abundance and mortality rates. Abundance and biomass estimates were used to estimate stock–recruit
Authors
John M. Syslo, Travis O. Brenden, Christopher S. Guy, Todd M . Koel, Patricia E. Bigelow, Philip D . Doepke, Jeffrey L. Arnold, Brian D. Ertel
Presence of microplastics in the food web of the largest high-elevation lake in North America
Microplastics have been documented in aquatic and terrestrial ecosystems throughout the world. However, few studies have investigated microplastics in freshwater fish diets. In this study, water samples and three trophic levels of a freshwater food web were investigated for microplastic presence: amphipods (Gammarus lacustris), Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri), and lake
Authors
Stephanie C. Driscoll, Hayley C. Glassic, Christopher S. Guy, Todd. M. Koel
Fort Peck paddlefish population survival and abundance in the Missouri River
Excessive fishing pressure can induce population declines or complete collapse of fisheries. Unless commercial and recreational fisheries for K-selected fishes, or those with slow growth and late maturation, are carefully managed, declines in abundance or fishery collapse is probable. Paddlefish Polyodon spathula,are a K-selected species that experienced historical declines in abundance as a resul
Authors
Hayley C. Glassic, Christopher S. Guy, Jay J. Rotella, Cody J. Nagel, David A. Schmetterling, Steven R. Dalbey
Diets of Longnose Sucker in Yellowstone Lake, Yellowstone National Park, U.S.A.
Invasive species introduction and expansion is the second greatest threat to global biodiversity decline after habitat degradation. Introduced in the 1930s, the benthivorous Longnose Sucker (Catostomus catostomus) became established in Yellowstone Lake, Wyoming, USA, and used tributary streams for spawning. With this introduction, concerns were raised regarding their possible competition for food
Authors
Kaitlyn M. Furey, Hayley C. Glassic, Christopher S. Guy, Todd M. Koel, Jeffrey L. Arnold, Philip D. Doepke, Patricia E. Bigelow
Gametogenesis and assessment of nonlethal tools to assign sex and reproductive condition in Burbot
Nonlethal tools (plasma sex steroid concentrations and ultrasound) for assigning sex and reproductive condition in Burbot Lota lota from Lake Roosevelt, Washington, were assessed. Gonadal tissue, blood plasma, and gonadal sonograms were collected monthly from November 2016 to March 2018. Gametogenesis was described by gonadal histology during an entire reproductive cycle to confirm sex and reprodu
Authors
Lauren M. McGarvey, Leif J. Halvorson, Jason E. Ilgen, Christopher S. Guy, Jason G. McLellan, Molly A. H. Webb
Targeting aggregations of telemetered Lake Trout to increase gillnetting suppression efficacy
Conserving Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri by suppressing invasive Lake Trout Salvelinus namaycush in Yellowstone Lake is a high priority for Yellowstone National Park resource managers. Here, we tested whether targeting telemetered Lake Trout could increase the efficacy of Lake Trout suppression by gill netting. Mobile acoustic tracking surveys were performed to identify
Authors
Jacob R. Williams, Christopher S. Guy, Todd M. Koel, Patricia E. Bigelow
Creating figures in R that meet the AFS style guide: Standardization and supporting script
Visual display of information in scientific and non‐scientific literature is the most efficient way to summarize large amounts data, focus the readers’ attention on patterns, and substantiate the message in the narrative. Figures often represent years of data collection and substantial monetary investment, and it is worth repeating the cliché “a [figure] is worth a thousand words.” Well‐designed f
Authors
Hayley C. Glassic, Kurt C. Heim, Christopher S. Guy
Organic pellet decomposition induces mortality of Lake Trout embryos in Yellowstone Lake
Yellowstone Lake is the site of actions to suppress invasive Lake Trout Salvelinus namaycush and restore native Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri and natural ecosystem function. Although gill netting is effective (Lake Trout λ ≤ 0.6 from 2012 through 2018), the effort costs more than US$2 million annually and only targets Lake Trout age 2 and older. To increase suppression
Authors
Todd M. Koel, Nathan A. Thomas, Christopher S. Guy, Philip D. Doepke, Drew J. MacDonald, Alex S. Poole, Wendy M. Sealey, Alexander V. Zale
Trout as native and non-native species: A management paradox
Native trout are threatened worldwide by introductions of non-native trout that in many cases are themselves threatened within their native range and historical habitats. This chapter focuses on this paradox and addresses how information gained to protect and restore a species in its native range can be used to suppress the same species outside its native range, where it may be invasive. We desc
Authors
Michael J. Hansen, Christopher S. Guy, Phaedra Budy, Thomas E. McMahon
Reproductive ecology and movement of pallid sturgeon in the upper Missouri River, Montana
Successful recruitment of endangered pallid sturgeon has not been documented in the upper Missouri River basin for decades, and research on the reproductive ecology of pallid sturgeon has been hindered by low sample size. A conservation propagation program was initiated in the 1990s, and the oldest age class of hatchery‐origin pallid sturgeon are becoming sexually mature increasing the number of r
Authors
Luke M. Holmquist, Christopher S. Guy, Anne Tews, David J. Trimpe, Molly A. H. Webb
In situ evaluation of benthic suffocation methods for suppression of invasive Lake Trout embryos in Yellowstone Lake
Suppression of invasive Lake Trout Salvelinus namaycush is an important management tool to use in native fish and ecosystem conservation throughout the U.S. Intermountain West. Lake Trout suppression, primarily by gill netting, has been ongoing in Yellowstone Lake, Yellowstone National Park, Wyoming, since 1995. Additional methods that cause mortality of Lake Trout embryos could be used simultaneo
Authors
Nathan A. Thomas, Christopher S. Guy, Todd M. Koel, Alexander V. Zale
First maturity and spawning periodicity of hatchery-origin pallid sturgeon in the upper Missouri River above Fort Peck Reservoir, Montana.
The pallid sturgeon Scaphirhynchus albus conservation propagation program has augmented declining wild populations since the 1990s and the older age classes of hatchery-origin fish are beginning to reach sexual maturity in the wild. Currently, the majority of the information available on the age and size at first maturity and spawning periodicity for pallid sturgeon in the upper basin is from capt
Authors
Luke Mathew Holmquist, Christopher S. Guy, Anne Tews, Molly A. H. Webb
Science and Products
- Publications
Filter Total Items: 40
Could ecological release buffer suppression efforts for non-native lake trout (Salvelinus namaycush) in Yellowstone Lake, Yellowstone National Park?
Yellowstone Lake in Yellowstone National Park, USA, has the longest ongoing suppression program for non-native lake trout (Salvelinus namaycush) in the western USA. Harvest data from the suppression program, along with data from an assessment program initiated in 2011, was used to estimate lake trout abundance and mortality rates. Abundance and biomass estimates were used to estimate stock–recruitAuthorsJohn M. Syslo, Travis O. Brenden, Christopher S. Guy, Todd M . Koel, Patricia E. Bigelow, Philip D . Doepke, Jeffrey L. Arnold, Brian D. ErtelPresence of microplastics in the food web of the largest high-elevation lake in North America
Microplastics have been documented in aquatic and terrestrial ecosystems throughout the world. However, few studies have investigated microplastics in freshwater fish diets. In this study, water samples and three trophic levels of a freshwater food web were investigated for microplastic presence: amphipods (Gammarus lacustris), Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri), and lakeAuthorsStephanie C. Driscoll, Hayley C. Glassic, Christopher S. Guy, Todd. M. KoelFort Peck paddlefish population survival and abundance in the Missouri River
Excessive fishing pressure can induce population declines or complete collapse of fisheries. Unless commercial and recreational fisheries for K-selected fishes, or those with slow growth and late maturation, are carefully managed, declines in abundance or fishery collapse is probable. Paddlefish Polyodon spathula,are a K-selected species that experienced historical declines in abundance as a resulAuthorsHayley C. Glassic, Christopher S. Guy, Jay J. Rotella, Cody J. Nagel, David A. Schmetterling, Steven R. DalbeyDiets of Longnose Sucker in Yellowstone Lake, Yellowstone National Park, U.S.A.
Invasive species introduction and expansion is the second greatest threat to global biodiversity decline after habitat degradation. Introduced in the 1930s, the benthivorous Longnose Sucker (Catostomus catostomus) became established in Yellowstone Lake, Wyoming, USA, and used tributary streams for spawning. With this introduction, concerns were raised regarding their possible competition for foodAuthorsKaitlyn M. Furey, Hayley C. Glassic, Christopher S. Guy, Todd M. Koel, Jeffrey L. Arnold, Philip D. Doepke, Patricia E. BigelowGametogenesis and assessment of nonlethal tools to assign sex and reproductive condition in Burbot
Nonlethal tools (plasma sex steroid concentrations and ultrasound) for assigning sex and reproductive condition in Burbot Lota lota from Lake Roosevelt, Washington, were assessed. Gonadal tissue, blood plasma, and gonadal sonograms were collected monthly from November 2016 to March 2018. Gametogenesis was described by gonadal histology during an entire reproductive cycle to confirm sex and reproduAuthorsLauren M. McGarvey, Leif J. Halvorson, Jason E. Ilgen, Christopher S. Guy, Jason G. McLellan, Molly A. H. WebbTargeting aggregations of telemetered Lake Trout to increase gillnetting suppression efficacy
Conserving Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri by suppressing invasive Lake Trout Salvelinus namaycush in Yellowstone Lake is a high priority for Yellowstone National Park resource managers. Here, we tested whether targeting telemetered Lake Trout could increase the efficacy of Lake Trout suppression by gill netting. Mobile acoustic tracking surveys were performed to identifyAuthorsJacob R. Williams, Christopher S. Guy, Todd M. Koel, Patricia E. BigelowCreating figures in R that meet the AFS style guide: Standardization and supporting script
Visual display of information in scientific and non‐scientific literature is the most efficient way to summarize large amounts data, focus the readers’ attention on patterns, and substantiate the message in the narrative. Figures often represent years of data collection and substantial monetary investment, and it is worth repeating the cliché “a [figure] is worth a thousand words.” Well‐designed fAuthorsHayley C. Glassic, Kurt C. Heim, Christopher S. GuyOrganic pellet decomposition induces mortality of Lake Trout embryos in Yellowstone Lake
Yellowstone Lake is the site of actions to suppress invasive Lake Trout Salvelinus namaycush and restore native Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri and natural ecosystem function. Although gill netting is effective (Lake Trout λ ≤ 0.6 from 2012 through 2018), the effort costs more than US$2 million annually and only targets Lake Trout age 2 and older. To increase suppressionAuthorsTodd M. Koel, Nathan A. Thomas, Christopher S. Guy, Philip D. Doepke, Drew J. MacDonald, Alex S. Poole, Wendy M. Sealey, Alexander V. ZaleTrout as native and non-native species: A management paradox
Native trout are threatened worldwide by introductions of non-native trout that in many cases are themselves threatened within their native range and historical habitats. This chapter focuses on this paradox and addresses how information gained to protect and restore a species in its native range can be used to suppress the same species outside its native range, where it may be invasive. We descAuthorsMichael J. Hansen, Christopher S. Guy, Phaedra Budy, Thomas E. McMahonReproductive ecology and movement of pallid sturgeon in the upper Missouri River, Montana
Successful recruitment of endangered pallid sturgeon has not been documented in the upper Missouri River basin for decades, and research on the reproductive ecology of pallid sturgeon has been hindered by low sample size. A conservation propagation program was initiated in the 1990s, and the oldest age class of hatchery‐origin pallid sturgeon are becoming sexually mature increasing the number of rAuthorsLuke M. Holmquist, Christopher S. Guy, Anne Tews, David J. Trimpe, Molly A. H. WebbIn situ evaluation of benthic suffocation methods for suppression of invasive Lake Trout embryos in Yellowstone Lake
Suppression of invasive Lake Trout Salvelinus namaycush is an important management tool to use in native fish and ecosystem conservation throughout the U.S. Intermountain West. Lake Trout suppression, primarily by gill netting, has been ongoing in Yellowstone Lake, Yellowstone National Park, Wyoming, since 1995. Additional methods that cause mortality of Lake Trout embryos could be used simultaneoAuthorsNathan A. Thomas, Christopher S. Guy, Todd M. Koel, Alexander V. ZaleFirst maturity and spawning periodicity of hatchery-origin pallid sturgeon in the upper Missouri River above Fort Peck Reservoir, Montana.
The pallid sturgeon Scaphirhynchus albus conservation propagation program has augmented declining wild populations since the 1990s and the older age classes of hatchery-origin fish are beginning to reach sexual maturity in the wild. Currently, the majority of the information available on the age and size at first maturity and spawning periodicity for pallid sturgeon in the upper basin is from captAuthorsLuke Mathew Holmquist, Christopher S. Guy, Anne Tews, Molly A. H. Webb