Boaters fly fishing on the Missouri River in Montana
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, and conservation biology. My research aims to understand the interactions between aquatic species and their environments to help guide conservation and management efforts. My research focuses on assessing how the impacts of various human stressors—climate change, invasive species, and habitat loss—impact native salmonids and freshwater ecosystems in the Rocky Mountains of the United States and Canada.
My research addresses various scientific and conservation issues, including:
- Predicting climate change impacts on native salmonids and freshwater ecosystems
- Evaluating invasive species effects on native fishes and ecosystems
- Conducting ecohydrological assessments of climate change and drought impacts
- Assessing life history and genetic diversity of native salmonids
- Investigating the status, threats, and conservation of threatened species
I enjoy multidisciplinary collaboration and advising graduate students in freshwater ecology and conservation biology. I participate in regional, national, and international science teams addressing climate change and transboundary river issues. My goal is to conserve native species and ecosystems for future generations through research-informed management and education.
Science and Products
Filter Total Items: 21
Climate change links fate of glaciers and rare alpine stream invertebrates in Glacier National Park
The extensive loss of glaciers in Glacier National Park (GNP) is iconic of the global impacts of climate warming in mountain ecosystems. However, little is known about how climate change may threaten alpine stream species, especially invertebrates, persisting below disappearing snow and ice masses in GNP. Two alpine stream invertebrates – the meltwater stonefly and the glacier stonefly – are...
Assessing the Vulnerability of Native Trout in the Northern Rockies: Linking Science and Management for Climate Adaptation
Trout are one of the most culturally, economically, and ecologically important groups of freshwater fishes in the Rocky Mountain region. However, human impacts and climate change are significantly altering freshwater ecosystems that support native trout species. Despite their broad importance, many of the region’s trout populations are threatened and some require immediate conservation efforts to
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.
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 lake...
Predicting Climate-Induced Expansions of Invasive Fish in the Pacific Northwest: Implications for Climate Adaptation of Native Salmon and Trout
The headwaters of the Columbia River Basin in the Northern Rocky Mountains region is widely recognized as a stronghold for native fish, containing some of the last remaining connected cold-water habitats for species such as the threatened bull trout and native westslope cutthroat trout. However, as temperatures rise, non-native invasive fish species could be poised to prosper in the region as cond
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 changing
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, yet ecologically important species such as bighorn sheep and black bear. The mountain ecosystems of GNP that support these species are dynamic...
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 associated...
Climate Change Impacts on Invasive Species in the Northwest: A Synthesis and Path Forward
Invasive species have increasingly severe consequences for ecosystems and human communities alike. The ecological impacts of invasive species are often irreversible, and include the loss of native species and the spread of disease. Implications for human communities include damaged water transportation systems, reduced crop yields, reduced forage quality for livestock, and widespread tree death -
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 establish...
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...
Montana trout fishing
Boaters fly fishing on the Missouri River in Montana
Trout fishing in Montana
Fly fishing for trout in one on Montana's rivers.
Fly fishing for trout in one on Montana's rivers.
Aquatic insect sampling in Glacier National Park
Researchers taking aquatic insect samples in a high-elevation Glacier National Park stream as part of ecohydrological monitoring efforts to study the effects of climate change on aquatic species and ecosystems.
Researchers taking aquatic insect samples in a high-elevation Glacier National Park stream as part of ecohydrological monitoring efforts to study the effects of climate change on aquatic species and ecosystems.
What a catch!
Angler holding a brown trout caught from a Montana River
Angler holding a brown trout caught from a Montana River
Spawning Westslope Cutthroat Trout in the Flathead
This is spawning westslope cutthroat trout captured in Langford Creek, North Fork Flathead River, Montana.
This is spawning westslope cutthroat trout captured in Langford Creek, North Fork Flathead River, Montana.
Science and Products
Filter Total Items: 21
Climate change links fate of glaciers and rare alpine stream invertebrates in Glacier National Park
The extensive loss of glaciers in Glacier National Park (GNP) is iconic of the global impacts of climate warming in mountain ecosystems. However, little is known about how climate change may threaten alpine stream species, especially invertebrates, persisting below disappearing snow and ice masses in GNP. Two alpine stream invertebrates – the meltwater stonefly and the glacier stonefly – are...
Assessing the Vulnerability of Native Trout in the Northern Rockies: Linking Science and Management for Climate Adaptation
Trout are one of the most culturally, economically, and ecologically important groups of freshwater fishes in the Rocky Mountain region. However, human impacts and climate change are significantly altering freshwater ecosystems that support native trout species. Despite their broad importance, many of the region’s trout populations are threatened and some require immediate conservation efforts to
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.
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 lake...
Predicting Climate-Induced Expansions of Invasive Fish in the Pacific Northwest: Implications for Climate Adaptation of Native Salmon and Trout
The headwaters of the Columbia River Basin in the Northern Rocky Mountains region is widely recognized as a stronghold for native fish, containing some of the last remaining connected cold-water habitats for species such as the threatened bull trout and native westslope cutthroat trout. However, as temperatures rise, non-native invasive fish species could be poised to prosper in the region as cond
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 changing
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, yet ecologically important species such as bighorn sheep and black bear. The mountain ecosystems of GNP that support these species are dynamic...
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 associated...
Climate Change Impacts on Invasive Species in the Northwest: A Synthesis and Path Forward
Invasive species have increasingly severe consequences for ecosystems and human communities alike. The ecological impacts of invasive species are often irreversible, and include the loss of native species and the spread of disease. Implications for human communities include damaged water transportation systems, reduced crop yields, reduced forage quality for livestock, and widespread tree death -
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 establish...
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...
Montana trout fishing
Boaters fly fishing on the Missouri River in Montana
Boaters fly fishing on the Missouri River in Montana
Trout fishing in Montana
Fly fishing for trout in one on Montana's rivers.
Fly fishing for trout in one on Montana's rivers.
Aquatic insect sampling in Glacier National Park
Researchers taking aquatic insect samples in a high-elevation Glacier National Park stream as part of ecohydrological monitoring efforts to study the effects of climate change on aquatic species and ecosystems.
Researchers taking aquatic insect samples in a high-elevation Glacier National Park stream as part of ecohydrological monitoring efforts to study the effects of climate change on aquatic species and ecosystems.
What a catch!
Angler holding a brown trout caught from a Montana River
Angler holding a brown trout caught from a Montana River
Spawning Westslope Cutthroat Trout in the Flathead
This is spawning westslope cutthroat trout captured in Langford Creek, North Fork Flathead River, Montana.
This is spawning westslope cutthroat trout captured in Langford Creek, North Fork Flathead River, Montana.