Clint Muhlfeld, Ph.D.
I am a Research Aquatic Ecologist for the USGS Northern Rocky Mountain Science Center stationed in Glacier National Park.
Research interests
I specialize in aquatic ecology, fisheries biology, ecohydrology, and conservation biology. My research focuses on understanding the complex interactions between aquatic species and their environments to guide conservation and management of freshwater fisheries and ecosystems. I focus on how human-driven stressors—such as drought, invasive species, and habitat degradation—impact native trout, valuable recreational fisheries, and freshwater ecosystems, particularly in the northern Rocky Mountains of the United States.
My research addresses various scientific and conservation issues, including:
- Predicting the impacts of environmental changes on native trout and their freshwater habitats
- Evaluating the effects of invasive species on native fishes and ecosystem health
- Conducting ecohydrological assessments of drought and water management impacts
- Investigating life history and genetic diversity of native salmonids
- Assessing the status, threats, and conservation of threatened species to inform management needs
I am passionate about multidisciplinary science collaboration and enjoy mentoring graduate students in fisheries and freshwater ecology. I also contribute to regional, national, and international science teams focused on transboundary river management and the sustainable use of freshwater resources. My ultimate goal is to conserve native species and ecosystems for future generations through research-informed management and education.
Science and Products
Filter Total Items: 23
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 the...
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 nonnative...
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...
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...
Predicting climate change effects on aquatic ecosystems in the Crown of the Continent
Climate change poses a serious threat to natural resources, biodiversity, and ecosystem services in the United States, especially in the Rocky Mountain Ecoregion. The Crown of the Continent Ecosystem (CCE) is considered one of the largest, most pristine, and biodiverse ecosystems in North America, spanning the northern Rocky Mountains of the United States and Canada. In the heart of the CCE is the...
Assessing the impacts of mining in the Transboundary Flathead and Kootenai River systems
The Transboundary Flathead and Kootenai Basins in Montana and British Columbia host some of the most diverse and unique native aquatic ecosystems throughout North America. Headwaters of these basin feed into Waterton-Glacier International Peace Park (U.S. and Canada) and Flathead Lake, and Lake Koocanusa and the Kootenai River in the U.S. Despite the tremendous historical and ecological value of...
Integrated bioassessment of imperiled alpine aquatic ecosystems using NPS vital signs and USGS research data: Implications for conservation under a warming climate
Climate warming in the mid- to high-latitudes and high-elevation mountainous regions is occurring more rapidly than anywhere else on Earth, causing extensive loss of glaciers and snowpack. The loss of glaciers in Glacier National Park (GNP) is iconic of the combined impacts of global warming and reduced snowpack−all remaining 25 glaciers are predicted to disappear by 2030. These changes will...
Evaluation of alternative dam operations on the movement and habitat use of bull trout and westslope cutthroat trout
The goal of this project is to quantify the operational impacts of Hungry Horse Dam on native bull trout and westslope cutthroat trout in the upper Flathead River system, Montana.
Webinar: Predicting Climate Change Impacts on Aquatic Ecosystems across the Pacific Northwest
View this webinar to learn more about the impacts of climate change on Northwest fishes.
The Past as a Prelude to the Future: Assessing Climate Effects on Native Trout in the U.S.
Salmonids (a family of fish that includes salmon, trout, and char) are a keystone species for both aquatic and terrestrial ecosystems, and can be an early warning indicator of ecosystem health. Salmonids also have strong societal values and contribute enormously to regional economies and Native American cultures. Today, many native salmonid populations are small, highly fragmented, and...
Predicting Climate Change Impacts on River Ecosystems and Salmonids across the Pacific Northwest
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...
Science and Products
Filter Total Items: 23
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 the...
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 nonnative...
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...
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...
Predicting climate change effects on aquatic ecosystems in the Crown of the Continent
Climate change poses a serious threat to natural resources, biodiversity, and ecosystem services in the United States, especially in the Rocky Mountain Ecoregion. The Crown of the Continent Ecosystem (CCE) is considered one of the largest, most pristine, and biodiverse ecosystems in North America, spanning the northern Rocky Mountains of the United States and Canada. In the heart of the CCE is the...
Assessing the impacts of mining in the Transboundary Flathead and Kootenai River systems
The Transboundary Flathead and Kootenai Basins in Montana and British Columbia host some of the most diverse and unique native aquatic ecosystems throughout North America. Headwaters of these basin feed into Waterton-Glacier International Peace Park (U.S. and Canada) and Flathead Lake, and Lake Koocanusa and the Kootenai River in the U.S. Despite the tremendous historical and ecological value of...
Integrated bioassessment of imperiled alpine aquatic ecosystems using NPS vital signs and USGS research data: Implications for conservation under a warming climate
Climate warming in the mid- to high-latitudes and high-elevation mountainous regions is occurring more rapidly than anywhere else on Earth, causing extensive loss of glaciers and snowpack. The loss of glaciers in Glacier National Park (GNP) is iconic of the combined impacts of global warming and reduced snowpack−all remaining 25 glaciers are predicted to disappear by 2030. These changes will...
Evaluation of alternative dam operations on the movement and habitat use of bull trout and westslope cutthroat trout
The goal of this project is to quantify the operational impacts of Hungry Horse Dam on native bull trout and westslope cutthroat trout in the upper Flathead River system, Montana.
Webinar: Predicting Climate Change Impacts on Aquatic Ecosystems across the Pacific Northwest
View this webinar to learn more about the impacts of climate change on Northwest fishes.
The Past as a Prelude to the Future: Assessing Climate Effects on Native Trout in the U.S.
Salmonids (a family of fish that includes salmon, trout, and char) are a keystone species for both aquatic and terrestrial ecosystems, and can be an early warning indicator of ecosystem health. Salmonids also have strong societal values and contribute enormously to regional economies and Native American cultures. Today, many native salmonid populations are small, highly fragmented, and...
Predicting Climate Change Impacts on River Ecosystems and Salmonids across the Pacific Northwest
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...