Robert Al-Chokhachy, Ph.D.
I am a research fisheries biologist with the U.S. Geological Survey’s Northern Rocky Mountain Science Center and an adjunct faculty in the Ecology Department at Montana State University in Bozeman, MT.
Research interests:
I am an applied biologist with goals of providing robust information to inform the management and conservation of aquatic ecosystems. My specific research focuses on improving our understanding of how natural and anthropogenic disturbances influence aquatic ecosystems, the interactions between native and non-native species, and how the life-history patterns and template of aquatic systems will be altered under anticipated changes in global and regional climates. Within this framework my research program consists of a combination of field studies and analytical studies to advance conservation and management and at the same time develop new paradigms in aquatic ecology. My research is built upon a premise of strong collaboration and interaction to facilitate effective research.
Mendenhall Project Title: Forecasting the Effects of Climate Change on the Interactions of Native and Nonnative Salmonids.
Education and Certifications
Ph.D. Aquatic Ecology. Utah State University
B.S. Biology. University of Utah
B.A. Economics. Bates College
Science and Products
Filter Total Items: 13
Filter Total Items: 54
Effects of land use on summer thermal regimes in critical salmonid habitats of the Pacific Northwest
The effect of climate change on stream temperature regimes is of significant concern to natural resource managers focused on protecting cold-water-dependent species. Nevertheless, understanding of how human land-use activities may act to exacerbate the effects of climate change on stream temperature regimes is limited. Using extensive stream temperature data with high-resolution climate and habita
Authors
Ryan Kovach, Clint C. Muhlfeld, Robert Al-Chokhachy, Jeffrey V. Ojala, Eric Archer
A portfolio framework for prioritizing conservation efforts for Yellowstone Cutthroat Trout populations
Managing and conserving native taxa are becoming increasingly challenging because of mounting threats and limited resources, predicating the need for frameworks to prioritize conservation actions. We integrated attributes of population persistence, genetic status, threats from nonnative species, and threats from climatic shifts to prioritize conservation actions for Yellowstone Cutthroat Trout Onc
Authors
Robert Al-Chokhachy, Bradley B. Shepard, Jason C. Burckhardt, Dan Garren, Scott Opitz, Todd M. Koel, Lee M. Nelson, Robert E. Gresswell
Proactive Rainbow Trout suppression reduces threat of hybridization in the Upper Snake River Basin
Preserving remaining nonhybridized populations Cutthroat Trout Oncorhynchus clarkii is a conservation priority often requiring management action. Although proactive programs for Rainbow Trout O. mykiss and hybrid suppression offer a flexible tool, particularly in large interconnected river basins, this management approach is used less frequently than alternatives such as barriers and piscicides. W
Authors
Ryan Kovach, Robert Al-Chokhachy, Tracy Stephens
Long-term population dynamics and conservation risk of migratory bull trout in the upper Columbia River basin
We used redd count data from 88 bull trout (Salvelinus confluentus) populations in the upper Columbia River basin to quantify local and regional patterns in population dynamics, including adult abundance, long-term trend, and population synchrony. We further used this information to assess conservation risk of metapopulations using eight population dynamic metrics associated with persistence. Loca
Authors
Ryan Kovach, Jonathan Armstrong, David Schmetterling, Robert Al-Chokhachy, Clint C. Muhlfeld
Status and conservation of Yellowstone cutthroat trout in the Greater Yellowstone Area
No abstract available.
Authors
Robert K. Al-Chokhachy, Bradley Shepard, Jason Burckhardt, Scott Opitz, Dan Garren, Todd M. Koel, Lee M. Nelson
Quantifying long-term population growth rates of threatened bull trout: challenges, lessons learned, and opportunities
Temporal symmetry models (TSM) represent advances in the analytical application of mark–recapture data to population status assessments. For a population of char, we employed 10 years of active and passive mark–recapture data to quantify population growth rates using different data sources and analytical approaches. Estimates of adult population growth rate were 1.01 (95% confidence interval = 0.8
Authors
Phaedra Budy, Tracy Bowerman, Robert K. Al-Chokhachy, Mary Conner, Howard Schaller
No evidence for ecological segregation protecting native trout from invasive hybridization
We appreciate the comments of Young et al. (2017) on our recent paper (Muhlfeld et al., 2017) concerning spatiotemporal dynamics of hybridization between native westslope cutthroat trout (Oncorhynchus clarkii lewisi; WCT) and introduced coastal rainbow trout (Oncorhynchus mykiss irideus; RBT). Nevertheless, we believe there is no evidence for “ecological segregation” protecting WCT from hybridizat
Authors
Ryan Kovach, Clint C. Muhlfeld, Robert K. Al-Chokhachy, Stephen J. Amish, Jeffrey L. Kershner, Robb F. Leary, Winsor H. Lowe, Gordon Luikart, Phil Matson, David Schmetterling, Bradley Shepard, Peter A. H. Westley, Diane Whited, Andrew R. Whiteley, Fred W. Allendorf
Evaluating species-specific changes in hydrologic regimes: an iterative approach for salmonids in the Greater Yellowstone Area (USA)
Despite the importance of hydrologic regimes to the phenology, demography, and abundance of fishes such as salmonids, there have been surprisingly few syntheses that holistically assess regional, species-specific trends in hydrologic regimes within a framework of climate change. Here, we consider hydrologic regimes within the Greater Yellowstone Area in the Rocky Mountains of western North America
Authors
Robert K. Al-Chokhachy, Adam J. Sepulveda, Andrew M. Ray, David P. Thoma, Michael T. Tercek
Legacy introductions and climatic variation explain spatiotemporal patterns of invasive hybridization in a native trout
Hybridization between invasive and native species, a significant threat to worldwide biodiversity, is predicted to increase due to climate-induced expansions of invasive species. Long-term research and monitoring are crucial for understanding the ecological and evolutionary processes that modulate the effects of invasive species. Using a large, multi-decade genetics dataset (N = 582 sites, 12,878
Authors
Clint C. Muhlfeld, Ryan P. Kovach, Robert K. Al-Chokhachy, Stephen J. Amish, Jeffrey L. Kershner, Robb F. Leary, Winsor H. Lowe, Gordon Luikart, Phil Matson, David A. Schmetterling, Bradley B. Shepard, Peter A. H. Westley, Diane Whited, Andrew R. Whiteley, Fred W. Allendorf
Climate, invasive species and land use drive population dynamics of a cold-water specialist
Climate change is an additional stressor in a complex suite of threats facing freshwater biodiversity, particularly for cold-water fishes. Research addressing the consequences of climate change on cold-water fish has generally focused on temperature limits defining spatial distributions, largely ignoring how climatic variation influences population dynamics in the context of other existing stresso
Authors
Ryan P. Kovach, Robert K. Al-Chokhachy, Diane C. Whited, David A. Schmetterling, Andrew M. Dux, Clint C. Muhlfeld
Life history characteristics and vital rates of Yellowstone Cutthroat Trout in two headwater basins
The Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri is native to the Rocky Mountains and has declined in abundance and distribution as a result of habitat degradation and introduced salmonid species. Many of its remaining strongholds are in headwater basins with minimal human disturbances. Understanding the life histories, vital rates, and behaviors of Yellowstone Cutthroat Trout within
Authors
Patrick Uthe, Robert K. Al-Chokhachy, Alexander V. Zale, Bradley B. Shepard, Thomas E. McMahon, Tracy Stephens
Influence of climate drivers on colonization and extinction dynamics of wetland-dependent species
Freshwater wetlands are particularly vulnerable to climate change. Specifically, changes in temperature, precipitation, and evapotranspiration (i.e., climate drivers) are likely to alter flooding regimes of wetlands and affect the vital rates, abundance, and distributions of wetland-dependent species. Amphibians may be among the most climate-sensitive wetland-dependent groups, as many species rely
Authors
Andrew M. Ray, William R. Gould, Blake R. Hossack, Adam J. Sepulveda, David P. Thoma, Debra A. Patla, Rob Daley, Robert K. Al-Chokhachy
Science and Products
Filter Total Items: 13
Filter Total Items: 54
Effects of land use on summer thermal regimes in critical salmonid habitats of the Pacific Northwest
The effect of climate change on stream temperature regimes is of significant concern to natural resource managers focused on protecting cold-water-dependent species. Nevertheless, understanding of how human land-use activities may act to exacerbate the effects of climate change on stream temperature regimes is limited. Using extensive stream temperature data with high-resolution climate and habita
Authors
Ryan Kovach, Clint C. Muhlfeld, Robert Al-Chokhachy, Jeffrey V. Ojala, Eric Archer
A portfolio framework for prioritizing conservation efforts for Yellowstone Cutthroat Trout populations
Managing and conserving native taxa are becoming increasingly challenging because of mounting threats and limited resources, predicating the need for frameworks to prioritize conservation actions. We integrated attributes of population persistence, genetic status, threats from nonnative species, and threats from climatic shifts to prioritize conservation actions for Yellowstone Cutthroat Trout Onc
Authors
Robert Al-Chokhachy, Bradley B. Shepard, Jason C. Burckhardt, Dan Garren, Scott Opitz, Todd M. Koel, Lee M. Nelson, Robert E. Gresswell
Proactive Rainbow Trout suppression reduces threat of hybridization in the Upper Snake River Basin
Preserving remaining nonhybridized populations Cutthroat Trout Oncorhynchus clarkii is a conservation priority often requiring management action. Although proactive programs for Rainbow Trout O. mykiss and hybrid suppression offer a flexible tool, particularly in large interconnected river basins, this management approach is used less frequently than alternatives such as barriers and piscicides. W
Authors
Ryan Kovach, Robert Al-Chokhachy, Tracy Stephens
Long-term population dynamics and conservation risk of migratory bull trout in the upper Columbia River basin
We used redd count data from 88 bull trout (Salvelinus confluentus) populations in the upper Columbia River basin to quantify local and regional patterns in population dynamics, including adult abundance, long-term trend, and population synchrony. We further used this information to assess conservation risk of metapopulations using eight population dynamic metrics associated with persistence. Loca
Authors
Ryan Kovach, Jonathan Armstrong, David Schmetterling, Robert Al-Chokhachy, Clint C. Muhlfeld
Status and conservation of Yellowstone cutthroat trout in the Greater Yellowstone Area
No abstract available.
Authors
Robert K. Al-Chokhachy, Bradley Shepard, Jason Burckhardt, Scott Opitz, Dan Garren, Todd M. Koel, Lee M. Nelson
Quantifying long-term population growth rates of threatened bull trout: challenges, lessons learned, and opportunities
Temporal symmetry models (TSM) represent advances in the analytical application of mark–recapture data to population status assessments. For a population of char, we employed 10 years of active and passive mark–recapture data to quantify population growth rates using different data sources and analytical approaches. Estimates of adult population growth rate were 1.01 (95% confidence interval = 0.8
Authors
Phaedra Budy, Tracy Bowerman, Robert K. Al-Chokhachy, Mary Conner, Howard Schaller
No evidence for ecological segregation protecting native trout from invasive hybridization
We appreciate the comments of Young et al. (2017) on our recent paper (Muhlfeld et al., 2017) concerning spatiotemporal dynamics of hybridization between native westslope cutthroat trout (Oncorhynchus clarkii lewisi; WCT) and introduced coastal rainbow trout (Oncorhynchus mykiss irideus; RBT). Nevertheless, we believe there is no evidence for “ecological segregation” protecting WCT from hybridizat
Authors
Ryan Kovach, Clint C. Muhlfeld, Robert K. Al-Chokhachy, Stephen J. Amish, Jeffrey L. Kershner, Robb F. Leary, Winsor H. Lowe, Gordon Luikart, Phil Matson, David Schmetterling, Bradley Shepard, Peter A. H. Westley, Diane Whited, Andrew R. Whiteley, Fred W. Allendorf
Evaluating species-specific changes in hydrologic regimes: an iterative approach for salmonids in the Greater Yellowstone Area (USA)
Despite the importance of hydrologic regimes to the phenology, demography, and abundance of fishes such as salmonids, there have been surprisingly few syntheses that holistically assess regional, species-specific trends in hydrologic regimes within a framework of climate change. Here, we consider hydrologic regimes within the Greater Yellowstone Area in the Rocky Mountains of western North America
Authors
Robert K. Al-Chokhachy, Adam J. Sepulveda, Andrew M. Ray, David P. Thoma, Michael T. Tercek
Legacy introductions and climatic variation explain spatiotemporal patterns of invasive hybridization in a native trout
Hybridization between invasive and native species, a significant threat to worldwide biodiversity, is predicted to increase due to climate-induced expansions of invasive species. Long-term research and monitoring are crucial for understanding the ecological and evolutionary processes that modulate the effects of invasive species. Using a large, multi-decade genetics dataset (N = 582 sites, 12,878
Authors
Clint C. Muhlfeld, Ryan P. Kovach, Robert K. Al-Chokhachy, Stephen J. Amish, Jeffrey L. Kershner, Robb F. Leary, Winsor H. Lowe, Gordon Luikart, Phil Matson, David A. Schmetterling, Bradley B. Shepard, Peter A. H. Westley, Diane Whited, Andrew R. Whiteley, Fred W. Allendorf
Climate, invasive species and land use drive population dynamics of a cold-water specialist
Climate change is an additional stressor in a complex suite of threats facing freshwater biodiversity, particularly for cold-water fishes. Research addressing the consequences of climate change on cold-water fish has generally focused on temperature limits defining spatial distributions, largely ignoring how climatic variation influences population dynamics in the context of other existing stresso
Authors
Ryan P. Kovach, Robert K. Al-Chokhachy, Diane C. Whited, David A. Schmetterling, Andrew M. Dux, Clint C. Muhlfeld
Life history characteristics and vital rates of Yellowstone Cutthroat Trout in two headwater basins
The Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri is native to the Rocky Mountains and has declined in abundance and distribution as a result of habitat degradation and introduced salmonid species. Many of its remaining strongholds are in headwater basins with minimal human disturbances. Understanding the life histories, vital rates, and behaviors of Yellowstone Cutthroat Trout within
Authors
Patrick Uthe, Robert K. Al-Chokhachy, Alexander V. Zale, Bradley B. Shepard, Thomas E. McMahon, Tracy Stephens
Influence of climate drivers on colonization and extinction dynamics of wetland-dependent species
Freshwater wetlands are particularly vulnerable to climate change. Specifically, changes in temperature, precipitation, and evapotranspiration (i.e., climate drivers) are likely to alter flooding regimes of wetlands and affect the vital rates, abundance, and distributions of wetland-dependent species. Amphibians may be among the most climate-sensitive wetland-dependent groups, as many species rely
Authors
Andrew M. Ray, William R. Gould, Blake R. Hossack, Adam J. Sepulveda, David P. Thoma, Debra A. Patla, Rob Daley, Robert K. Al-Chokhachy