Muhlfeld, Clint C., Thomas E. McMahon, and Durae Belcer. 2009. Spatial and temporal dynamics of spawning between native westslope cutthroat trout (Oncorhynchus clarkii lewisi), introduced rainbow trout (O. mykiss), and their hybrids. Canadian Journal of Fisheries and Aquatic Sciences 66:1153-1168.
Clint Muhlfeld, Ph.D.
Biography
Associate Research Professor
Flathead Lake Biological Station, University of Montana
Education
Ph.D. 2008. Fish and Wildlife Biology, Montana State University, Bozeman
M.S. 1999. Fishery Resources, University of Idaho, Moscow
B.S. 1994. Aquatic Biology, University of Montana, Missoula; University of Maine, Orono
Research interests
I am a Research Aquatic Ecologist for the USGS Northern Rocky Mountain Science Center stationed in Glacier National Park and Associate Research Professor at the University of Montana’s Flathead Lake Biological Station. My general research interests encompass the fields of aquatic ecology, fisheries biology, and conservation biology. My research goal is to understand how aquatic species interact with physical and biological templates over space and time to inform conservation and management. Specifically, my applied research focuses on assessing how human stressors – invasive species, habitat modification, and climate change – influence native salmonids and rare alpine macroinvertebrates in the Rocky Mountains of United States and Canada.
My research spans a range of scientific and conservation issues from examining evolutionary and ecological impacts of invasive species on native fishes, assessing life history and genetic diversity of native salmonids, assessing the status of threatened freshwater species, investigating the impacts of dams and barriers on aquatic species and ecosystems, developing quantitative models (e.g., stream temperature, instream flow/habitat, bioenergetics, riverscape connectivity, population viability) to predict species’ responses to environmental change, to understanding and predicting the impacts of climate change on freshwater species and ecosystems.
I particularly enjoy collaboration and multidisciplinary research, and advising and educating graduate students working on freshwater ecology and conservation biology projects. Currently, I actively participate on several regional, national, and international science teams that address natural resource issues facing aquatic ecosystems. My hope is that the ecological integrity of aquatic ecosystems will be conserved for future generations through research-informed management and education.
Science and Products
Date published: October 17, 2018
Status: Active Integrated Ecohydrological Science in the Northern Rocky Mountains — the variability of water availability and the effects on ecosystems
Our primary goal is to better understand and characterize how stream environments and the ecosystems they support are influenced by climate change and drought in the Northern Rocky Mountains.
Contacts: Clint Muhlfeld, Ph.D., Robert Al-Chokhachy, Ph.D.
Attribution: Ecosystems, Northern Rocky Mountain Science Center
Date published: May 1, 2018
Status: Active Drought and Ecological Flows
As part of the USGS Fisheries program, ecological flows, or the relationships between quality, quantity, and timing of water flows and ecological response of aquatic biota and ecosystems; and related ecosystem services are being investigated.
Contacts: Clint Muhlfeld, Ph.D.
Attribution: Ecosystems, Fisheries Program
Date published: May 1, 2018
Status: Active Energy Development and Aquatic Ecosystems
USGS is advancing science on the impacts of energy development on aquatic ecosystems.
Contacts: Clint Muhlfeld, Ph.D.
Date published: January 4, 2018
Status: Active Experimental suppression of invasive lake trout: Implications for conservation of imperiled bull trout in Glacier National Park
After 14,000 years of dominance, Glacier National Park’s (GNP) greatest native aquatic predator is at high risk of extirpation (local extinction) in several lakes on the western slopes of the Continental Divide. The decline of threatened bull trout in GNP is directly attributed to the invasion and establishment of nonnative lake trout, which consistently displace bull trout in systems where...
Contacts: Clint Muhlfeld, Ph.D.
Date published: January 1, 2018
Status: Active Understanding Climate Impacts on Native and Invasive Fish for Conservation, Management, and Economic Goals in the Northern Rockies
As the origin of three major basins that drain the Columbia, Missouri, and Saskatchewan rivers, Montana is the hydrologic apex for North America. The Northern Rocky Mountain region is home to some of the last remaining interconnected habitats for many native fishes, including the threatened bull trout and native westslope cutthroat trout. The Northern Rockies are also experiencing rapidly...
Attribution: Climate Adaptation Science Centers
Date published: September 13, 2017
Status: Active Science in Glacier National Park
Glacier National Park (GNP) is considered a stronghold for a large diversity of plant and animal species and harbors some of the last remaining populations of threatened and endangered species such as grizzly bear and bull trout, as well as non threatened keystone species such as bighorn sheep and black bear. The mountain ecosystems of GNP that support these species are dynamic and influenced...
Date published: February 2, 2017
Status: Active Western Waters Invasive Species and Disease Research Program
Researchers at the Northern Rocky Mountain Science Center's Western Waters Invasive Species and Disease Research Program work extensively with federal, state, tribal, regional, and local partners to deliver science to improve early detection and prevention of invasive species and disease; understand complex interactions that promote invasive species and disease, and their impacts (and...
Date published: March 10, 2016
Status: Active Translocation of imperiled fishes: Conservation introduction of threatened bull trout in Glacier National Park
There is an urgent need to consider more aggressive and direct interventions for conservation of freshwater fishes threatened by invasive species, habitat loss, and climate change. Conservation introduction - moving species to areas outside their previous range, where conditions are predicted to be more suitable - is one type of translocation strategy that fisheries managers can use to...
Contacts: Clint Muhlfeld, Ph.D.
Date published: March 9, 2016
Predicting climate change impacts on river ecosystems and salmonids across the Pacific Northwest: Combining vulnerability modeling, landscape genomics, and economic evaluations for conservation
Salmonids – a group of coldwater adapted fishes of enormous ecological and socio-economic value – historically inhabited a variety of freshwater habitats throughout the Pacific Northwest (PNW). Over the past century, however, populations have dramatically declined due to habitat loss, overharvest, and invasive species. Consequently, many populations are listed as threatened or endangered under...
Contacts: Clint Muhlfeld, Ph.D.
Attribution: Northern Rocky Mountain Science Center
Date published: March 8, 2016
Status: Active Genetic status and distribution of native westslope cutthroat trout in Glacier National Park
After 14,000 years of surviving extreme environmental events, such as floods, fires and glaciations, Glacier’s greatest native trout is at high risk of disappearing from several streams and lakes east and west of the Continental Divide. The decline of westslope cutthroat trout (Oncorhynchus clarkii lewisi; WCT) in Glacier National Park (GNP) has been attributed to the establishment of...
Contacts: Clint Muhlfeld, Ph.D.
Date published: March 7, 2016
Status: Active Evolutionary mechanisms influencing the spread of hybridization: genomics, fitness and dispersal
Invasive species and hybridization (reproduction between different species or subspecies) – among the most serious threats to native species and biodiversity – provide some of the richest opportunities for “natural experiments” in evolutionary biology. New genomic technologies, combined with long-term hybridization studies in natural populations, provide exciting opportunities to advance our...
Contacts: Clint Muhlfeld, Ph.D.
Date published: March 6, 2016
Status: Active Using the past as a prelude to the future to assess climate effects on native trout across the United States
Future climate change is expected to dramatically alter the structure and function of freshwater ecosystems that support salmonid species. The response of salmonids to climate change will vary through space and time and manifest in both known and currently unknown ways. A potentially rich source of understanding of how salmonids interact with climate lies in a unified retrospective analysis of...
Contacts: Clint Muhlfeld, Ph.D.
Year Published: 2021
Influence of water temperature and biotic interactions on the distribution of westslope cutthroat trout (Oncorhynchus clarkii lewisi) in a population stronghold under climate change
Climate warming is expected to have substantial impacts on native trout across the Rocky Mountains, but there is little understanding of how these changes affect future distributions of co-occurring native fishes within population strongholds. We used mixed-effects logistic regression to investigate the role of abiotic (e.g., temperature) and...
Heinle, Kadie; Eby, Lisa A; Muhlfeld, Clint C.; Steed, Amber; Jones, Leslie; D'Angelo, Vincent S.; Whiteley, Andrew R.; Hubblewhite, MarkAttribution: Northern Rocky Mountain Science Center, Ecosystems
Year Published: 2021
Hybridization alters growth and migratory life-history expression of native trout
Human-mediated hybridization threatens many native species, but the effects of introgressive hybridization on life-history expression are rarely quantified, especially in vertebrates. We quantified the effects of non-native rainbow trout admixture on important life-history traits including growth and partial migration behavior in three populations...
Strait, Jeffrey; Eby, Lisa A; Kovach, Ryan P.; Muhlfeld, Clint C.; Boyer, Matthew; Amish, Stephen J.; Smith, Seth; Lowe, Winsor H.; Luikart, GordonAttribution: Northern Rocky Mountain Science Center, Ecosystems
Year Published: 2020
An interactive data visualization framework for exploring geospatial environmental datasets and model predictions
With the rise of large-scale environmental models comes new challenges for how we best utilize this information in research, management and decision making. Interactive data visualizations can make large and complex datasets easier to access and explore, which can lead to knowledge discovery, hypothesis formation and improved understanding. Here,...
Walker, Jeffrey D; Letcher, Benjamin; Rodgers, Kirk D.; Muhlfeld, Clint C.; D'Angelo, Vincent S.Attribution: Leetown Science Center, Northern Rocky Mountain Science Center, Lower Mississippi-Gulf Water Science Center, Eastern Ecological Science Center, Ecosystems, Region 1: North Atlantic-Appalachian, Region 2: South Atlantic-Gulf (Includes Puerto Rico and the U.S. Virgin Islands), Region 4: Mississippi Basin
Year Published: 2020
Specialized meltwater biodiversity persists despite widespread deglaciation
Glaciers are important drivers of environmental heterogeneity and biological diversity across mountain landscapes. Worldwide, glaciers are receding rapidly due to climate change, with important consequences for biodiversity in mountain ecosystems. However, the effects of glacier loss on biodiversity have never been quantified across a mountainous...
Muhlfeld, Clint C.; Cline, Timothy Joseph; Giersch, J. Joseph; Peitzsch, Erich; Florentine, Caitlyn; Jacobsen, Dean; Hotaling, Scott
Year Published: 2020
Climate-induced expansions of invasive species in the Pacific Northwest, North America: A synthesis of observations and projections
Climate change may facilitate the expansion of non-native invasive species (NIS) in aquatic and terrestrial systems. However, empirical evidence remains scarce and poorly synthesized at scales necessary for effective management. We conducted a literature synthesis to assess the state of research on the observed and predicted effects of climate...
Gervais, Jennifer; Kovach, Ryan P.; Sepulveda, Adam J.; Al-Chokhachy, Robert K.; Giersch, J. Joseph; Muhlfeld, Clint C.Attribution: Northern Rocky Mountain Science Center, Ecosystems
Year Published: 2020
A call for global action to conserve native trout in the 21st century and beyond
Trout and char (hereafter, trout ) represent some of the more culturally, economically and ecologically important taxa of freshwater fishes worldwide (Kershner, Williams, Gresswell, & Lobón‐Cerviá, 2019a). Native to all continents in the Northern Hemisphere (as well as western Mediterranean Africa), trout belong to seven genera...
Dauwalter, Daniel C.; Duchi, Antonino; Epifanio, John; Gandolfi, A.J.; Gresswell, Robert E.; Juanes, Francis; Kershner, Jeffrey L.; Lobón-Cerviá, Javier; McGinnity, Philip; Meraner, Andreas; Mikheev, Pavel; Morita, Kentaro; Muhlfeld, Clint C.; Pinter, Kurt; Post, John; Unfer, Gunther; Vøllestad, Leif Asbjørn; Williams, Jack E.Attribution: Northern Rocky Mountain Science Center, Ecosystems
Year Published: 2020
Global status of trout and char: Conservation challenges in the twenty-first century
Freshwater ecosystems are among the most threatened ecosystems in the world (Richter et al. 1997; Strayer and Dudgeon 2010), and freshwater fishes may now be the most threatened group of vertebrates (Ricciardi and Rasmussen 1999; Vorosmarty et al. 2010; Darwall and Freyhof 2016). Of the 7,300 freshwater fish species globally assessed by the...
Muhlfeld, Clint C.; Dauwalter, Daniel C.; D'Angelo, Vincent S.; Ferguson, Andrew; Giersch, J. Joseph; Impson, Dean; Koizumi, Itsuro; Kovach, Ryan; McGinnity, Philip; Schoeffmann, Johannes; Epifanio, John; Vøllestad, Leif AsbjørnAttribution: Northern Rocky Mountain Science Center, Ecosystems
Year Published: 2019
Consistent compensatory growth offsets poor condition in trout populations
1. Compensatory growth – when individuals in poor condition grow rapidly to “catch up” to conspecifics – may be a mechanism that allows individuals to tolerate stressful environmental conditions, both abiotic and biotic. This phenomenon has been documented fairly widely in laboratory and field experiments, but evidence for compensatory growth in...
Al-Chokhachy, Robert; Kovach, Ryan; Sepulveda, Adam J.; Strait, Jeff; Shepard, Bradley B.; Muhlfeld, Clint C.Attribution: Northern Rocky Mountain Science Center, Ecosystems
Year Published: 2019
Microbial assemblages reflect environmental heterogeneity in alpine streams
Alpine streams are dynamic habitats harboring substantial biodiversity across small spatial extents. The diversity of alpine stream biota is largely reflective of environmental heterogeneity stemming from varying hydrological sources. Globally, alpine stream diversity is under threat as meltwater sources recede and stream conditions become...
Hotaling, Scott; Foley, Mary E.; Zeglin, Lydia; Finn, Debra S.; Tronstad, Lusha M.; Giersch, J. Joseph; Muhlfeld, Clint C.; Weisrock, David W.Attribution: Northern Rocky Mountain Science Center, Ecosystems
Year Published: 2019
An integrated framework for ecological drought across riverscapes of North America
Climate change is increasing the severity and extent of extreme droughts events, posing a critical threat to freshwater ecosystems, particularly with increasing human demands for diminishing water supplies. Despite the importance of drought as a significant driver of ecological and evolutionary dynamics, current understanding of drought...
Kovach, Ryan; Dunham, Jason B.; Al-Chokhachy, Robert; Snyder, Craig; Beever, Erik A.; Pederson, Gregory T.; Lynch, Abigail; Hitt, Nathaniel P.; Konrad, Christopher P.; Jaeger, Kristin; Rea, Alan H.; Sepulveda, Adam J.; Lambert, Patrick M.; Stoker, Jason M.; Giersch, J. Joseph; Muhlfeld, Clint C.
Year Published: 2019
Challenges in Columbia River fisheries conservation: Response to Duda et al.
The salmonid fisheries of the Columbia River Basin (CRB) have enormous socioeconomic, cultural, and ecological importance to numerous diverse stakeholders (e.g., state, federal, tribal, nonprofit), and there are a wide array of opinions and perspectives on how these fisheries should be managed. Although we appreciate Duda et al.’s commentary, it...
Hand, Brian K.; Flint, Courtney G.; Frissell, Chris A.; Muhlfeld, Clint C.; Devlin, Shawn P.; Kennedy, Brian P.; Crabtree, Robert L.; McKee, Arthur; Luikart, Gordon; Stanford, Jack A.Attribution: Northern Rocky Mountain Science Center, Ecosystems
Year Published: 2019
Congruent population genetic structure but differing depths of divergence for three alpine stoneflies with similar ecology and geographic distributions
Comparative population genetic studies provide a powerful means for assessing the degree to which evolutionary histories may be congruent among taxa while also highlighting the potential for cryptic diversity within existing species.In the Rocky Mountains, three confamilial stoneflies (Zapada glacier , Lednia tumana , and ...
Hotaling, Scott; Giersch, J. Joseph; Finn, Debra S.; Tronstad, Lusha M.; Jordan, Steve; Serpa, Larry; Call, Ronald; Muhlfeld, Clint C.; Weisrock, David W.Attribution: Northern Rocky Mountain Science Center, Ecosystems
Pre-USGS Publications
Muhlfeld, Clint C., Thomas E. McMahon, Matthew C. Boyer, and Robert E. Gresswell. 2009. Local-habitat, watershed, and biotic factors in the spread of hybridization between native westslope cutthroat trout and introduced rainbow trout. Transactions of the American Fisheries Society 138:1036-1051.
Boyer, Matthew C., Clint C. Muhlfeld, and Fred Allendorf. 2008. Rainbow trout invasion and the spread of hybridization with westslope cutthroat trout. Canadian Journal of Fisheries and Aquatic Sciences 65:658-669.
Muhlfeld, Clint C., David H. Bennett, Kirk Steinhorst, Brian Marotz, and Matthew C. Boyer. 2008. Using bioenergetics modeling to estimate consumption of native juvenile salmonids by nonnative northern pike in the upper Flathead River system, Montana. North American Journal of Fisheries Management 28:636-648.
Date published: April 13, 2016
CDFISH: A landscape genetics program to simulate gene flow in complex riverscapes under a wide range of environmental scenarios for aquatic organisms
CDFISH: A landscape genetics program to simulate gene flow in complex riverscapes under a wide range of environmental scenarios for aquatic organisms.
Attribution: Northern Rocky Mountain Science Center
Date published: September 3, 2021
Multiple Climate Change Challenges For Native Cutthroat Trout Discussed in National Geographic Article
NOROCK scientist Clint Muhlfeld discussed the direct and indirect effects of climate change on native cutthroat trout in western Montana in a National Geographic article. Specifically, Clint spoke about the effects of altered streamflows and hybridizing with a nonnative fish species.
Date published: September 6, 2017
Warmer and Longer Summers Portend Increased Stream Temperatures in the Northern Rockies
A new U.S. Geological Survey study provides a larger window into the future for understanding how seasonal stream temperatures may change in one of the most ecologically diverse ecosystems in North America – the Crown of the Continent Ecosystem, USA and Canada.
Attribution: Northern Rocky Mountain Science Center
Date published: April 4, 2017
Hybridization between Native and Invasive Trout is Increasing in the West
Hybridization, or the interbreeding of species, is increasing between native and invasive trout across the northern Rocky Mountains, according to a study released Tuesday by the U.S. Geological Survey and partners.
Date published: June 24, 2016
For Nature, Gravel-Bed Rivers Most Important Feature in Mountainous Western North America
MISSOULA – Gravel-bed river floodplains are some of the most ecologically important habitats in North America, according to a new study by scientists from the U.S. and Canada. Their research shows how broad valleys coming out of glaciated mountains provide highly productive and important habitat for a large diversity of aquatic, avian and terrestrial species.
Attribution: Northern Rocky Mountain Science Center
Date published: May 12, 2015
Climate Change Threatens Native Trout Diversity
Scientists have discovered that the diversity of a threatened native trout species will likely decrease due to future climate change.
Date published: December 4, 2014
Rare Insect Found Only in Glacier National Park Imperiled by Melting Glaciers
The persistence of an already rare aquatic insect, the western glacier stonefly, is being imperiled by the loss of glaciers and increased stream temperatures due to climate warming in mountain ecosystems, according to a new study released in Freshwater Science.
Date published: May 25, 2014
Climate Change Accelerates Hybridization between Native and Invasive Species of Trout
Scientists have discovered that the rapid spread of hybridization between a native species and an invasive species of trout in the wild is strongly linked to changes in climate.