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
Long-term population dynamics and conservation risk of migratory bull trout in the upper Columbia River basin
Status and conservation of Yellowstone cutthroat trout in the Greater Yellowstone Area
Quantifying long-term population growth rates of threatened bull trout: challenges, lessons learned, and opportunities
No evidence for ecological segregation protecting native trout from invasive hybridization
Evaluating species-specific changes in hydrologic regimes: an iterative approach for salmonids in the Greater Yellowstone Area (USA)
Legacy introductions and climatic variation explain spatiotemporal patterns of invasive hybridization in a native trout
Climate, invasive species and land use drive population dynamics of a cold-water specialist
Life history characteristics and vital rates of Yellowstone Cutthroat Trout in two headwater basins
Influence of climate drivers on colonization and extinction dynamics of wetland-dependent species
Conservation of native Pacific trout diversity in western North America
Linkages between unpaved forest roads and streambed sediment: why context matters in directing road restoration
Are brown trout replacing or displacing bull trout populations in a changing climate?
Science and Products
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Filter Total Items: 51
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. LocaAuthorsRyan Kovach, Jonathan Armstrong, David Schmetterling, Robert Al-Chokhachy, Clint C. MuhlfeldStatus and conservation of Yellowstone cutthroat trout in the Greater Yellowstone Area
No abstract available.AuthorsRobert K. Al-Chokhachy, Bradley Shepard, Jason Burckhardt, Scott Opitz, Dan Garren, Todd M. Koel, Lee M. NelsonQuantifying 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 = 0.8AuthorsPhaedra Budy, Tracy Bowerman, Robert K. Al-Chokhachy, Mary Conner, Howard SchallerNo 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 hybridizatAuthorsRyan 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. AllendorfEvaluating 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 AmericaAuthorsRobert K. Al-Chokhachy, Adam J. Sepulveda, Andrew M. Ray, David P. Thoma, Michael T. TercekLegacy 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, 12,878AuthorsClint 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. AllendorfClimate, 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 stressoAuthorsRyan P. Kovach, Robert K. Al-Chokhachy, Diane C. Whited, David A. Schmetterling, Andrew M. Dux, Clint C. MuhlfeldLife 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 withinAuthorsPatrick Uthe, Robert K. Al-Chokhachy, Alexander V. Zale, Bradley B. Shepard, Thomas E. McMahon, Tracy StephensInfluence 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 relyAuthorsAndrew M. Ray, William R. Gould, Blake R. Hossack, Adam J. Sepulveda, David P. Thoma, Debra A. Patla, Rob Daley, Robert K. Al-ChokhachyConservation of native Pacific trout diversity in western North America
Pacific trout Oncorhynchus spp. in western North America are strongly valued in ecological, socioeconomic, and cultural views, and have been the subject of substantial research and conservation efforts. Despite this, the understanding of their evolutionary histories, overall diversity, and challenges to their conservation is incomplete. We review the state of knowledge on these important issues, fAuthorsBrooke E. Penaluna, Alicia Abadía-Cardoso, Jason B. Dunham, Francisco J García de León, Robert E. Gresswell, Arturo Ruiz Luna, Eric B. Taylor, Bradley B. Shepard, Robert K. Al-Chokhachy, Clint C. Muhlfeld, Kevin R. Bestgen, Kevin H. Rogers, Marco A Escalante, Ernest R. Keeley, Gabriel Temple, Jack E. Williams, Kathleen Matthews, Ron Pierce, Richard L. Mayden, Ryan Kovach, John Carlos Garza, Kurt D. FauschLinkages between unpaved forest roads and streambed sediment: why context matters in directing road restoration
Unpaved forest roads remain a pervasive disturbance on public lands and mitigating sediment from road networks remains a priority for management agencies. Restoring roaded landscapes is becoming increasingly important for many native coldwater fishes that disproportionately rely on public lands for persistence. However, effectively targeting restoration opportunities requires a comprehensive underAuthorsRobert K. Al-Chokhachy, Tom A. Black, Cameron Thomas, Charlie H. Luce, Bruce Rieman, Richard Cissel, Anne Carlson, Shane Hendrickson, Eric K. Archer, Jeffrey L. KershnerAre brown trout replacing or displacing bull trout populations in a changing climate?
Understanding how climate change may facilitate species turnover is an important step in identifying potential conservation strategies. We used data from 33 sites in western Montana to quantify climate associations with native bull trout (Salvelinus confluentus) and non-native brown trout (Salmo trutta) abundance and population growth rates (λ). We estimated λ using exponential growth state spaceAuthorsRobert K. Al-Chokhachy, David A. Schmetterling, Chris Clancy, Pat Saffel, Ryan Kovach, Leslie Nyce, Brad Liermann, Wade A. Fredenberg, Ron Pierce