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Timothy Cline, PhD (Former Employee)

Science and Products

Native Westslope Cutthroat Trout

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...
By
Climate Adaptation Science Centers
Assessing the Vulnerability of Native Trout in the Northern Rockies: Linking Science and Management for Climate Adaptation

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
Learn More

Climate change vulnerability of Arctic char across Scandinavia Climate change vulnerability of Arctic char across Scandinavia

Climate change is anticipated to cause species to shift their ranges upward and poleward, yet space for tracking suitable habitat conditions may be limited for range-restricted species at the highest elevations and latitudes of the globe. Consequently, range-restricted species inhabiting Arctic freshwater ecosystems, where global warming is most pronounced, face the challenge of coping...
Authors
Clint C. Muhlfeld, Timothy Cline, Anders Finstad, Dag O. Hessen, Sam Perrin, Jens Thaulow, Diane Whited, Leif Asbjorn Vollestad
By
Ecosystems Mission Area, Northern Rocky Mountain Science Center

Declines in body size of sockeye salmon associated with increased competition in the ocean Declines in body size of sockeye salmon associated with increased competition in the ocean

Declining body sizes have been documented for several species of Pacific salmon; however, whether size declines are caused mainly by ocean warming or other ecological factors, and whether they result primarily from trends in age at maturation or changing growth rates remain poorly understood. We quantified changes in mean body size and contributions from shifting size-at-age and age...
Authors
Jan Ohlberger, Timothy Joseph Cline, Daniel Schindler, Bert Lewis
By
Ecosystems Mission Area, Northern Rocky Mountain Science Center

High dispersal rates in hybrids drive expansion of maladaptive hybridization High dispersal rates in hybrids drive expansion of maladaptive hybridization

Hybridization between native and invasive species, a major cause of biodiversity loss, can spread rapidly even when hybrids have reduced fitness. This paradox suggests that hybrids have greater dispersal rates than non-hybridized individuals, yet this mechanism has not been empirically tested in animal populations. Here, we test if non-native genetic introgression increases reproductive...
Authors
Samuel Bourret, Ryan P. Kovach, Timothy Joseph Cline, Jeffrey Strait, Clint C. Muhlfeld
By
Ecosystems Mission Area, Northern Rocky Mountain Science Center

Socioeconomic resilience to climatic extremes in a freshwater fishery Socioeconomic resilience to climatic extremes in a freshwater fishery

Heterogeneity is a central feature of ecosystem resilience, but how this translates to socioeconomic resilience depends on people’s ability to track shifting resources in space and time. Here, we quantify how climatic extremes have influenced how people (fishers) track economically valuable ecosystem services (fishing opportunities) across a range of spatial scales in rivers of the...
Authors
Timothy Joseph Cline, Clint C. Muhlfeld, Ryan P. Kovach, Robert Al-Chokhachy, David Schmetterling, Diane Whited, Abigail Lynch
By
Ecosystems Mission Area, Climate Adaptation Science Centers, Northern Rocky Mountain Science Center

Stream size, temperature, and density explain body sizes of freshwater salmonids across a range of climate conditions Stream size, temperature, and density explain body sizes of freshwater salmonids across a range of climate conditions

Climate change and anthropogenic activities are altering the body sizes of fishes, yet our understanding of factors influencing body size for many taxa remains incomplete. We evaluated the relationships between climate, environmental, and landscape attributes and the body size of different taxa of freshwater trout (Salmonidae) in the USA. Hierarchical spatial modeling across a gradient...
Authors
Robert K. Al-Chokhachy, Benjamin Letcher, Clint C. Muhlfeld, Jason B. Dunham, Timothy Joseph Cline, Nathaniel P. Hitt, James Roberts, David Schmetterling
By
Ecosystems Mission Area, Fort Collins Science Center, Eastern Ecological Science Center, Northern Rocky Mountain Science Center

A framework to integrate innovations in invasion science for proactive management A framework to integrate innovations in invasion science for proactive management

Invasive alien species (IAS) are a rising threat to biodiversity, national security, and regional economies, with impacts in the hundreds of billions of U.S. dollars annually. Proactive or predictive approaches guided by scientific knowledge are essential to keeping pace with growing impacts of invasions under climate change. Although the rapid development of diverse technologies and...
Authors
Charles B. van Rees, Brian K. Hand, Sean C. Carter, Charles Bargeron, Timothy Joseph Cline, Wesley M. Daniel, Jason A. Ferrante, Keith Gaddis, Margaret E. Hunter, Catherine S. Jarnevich, Melodie A. McGeoch, Jeffrey T. Morisette, Matthew E. Neilson, Helen E. Roy, Mary Ann Rozance, Adam Sepulveda, Rebekah D. Wallace, Diane Whited, Taylor Wilcox, John S. Kimball, Gordon Luikart
By
Ecosystems Mission Area, Fort Collins Science Center, Northern Rocky Mountain Science Center, Wetland and Aquatic Research Center

Climate change and expanding invasive species drive widespread declines of native trout in the northern Rocky Mountains, USA Climate change and expanding invasive species drive widespread declines of native trout in the northern Rocky Mountains, USA

Climate change and invasive species are major threats to native biodiversity, but few empirical studies have examined their combined effects at large spatial and temporal scales. Using 21,917 surveys collected over 30 years, we quantified the impacts of climate change on the past and future distributions of five interacting native and invasive trout species throughout the northern Rocky...
Authors
Donovan A. Bell, Ryan P. Kovach, Clint C. Muhlfeld, Robert Al-Chokhachy, Timothy Joseph Cline, Diane C. Whited, David Schmetterling, Paul M Lukacs, Andrew R. Whiteley
By
Ecosystems Mission Area, Northern Rocky Mountain Science Center

Specialized meltwater biodiversity persists despite widespread deglaciation 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 region, primarily due to a lack of...
Authors
Clint C. Muhlfeld, Timothy Joseph Cline, J. Joseph Giersch, Erich Peitzsch, Caitlyn Florentine, Dean Jacobsen, Scott Hotaling
By
Ecosystems Mission Area, Ecosystems Land Change Science Program, Northern Rocky Mountain Science Center

Do Daphnia use metalimnetic organic matter in a north temperate lake? An analysis of vertical migration Do Daphnia use metalimnetic organic matter in a north temperate lake? An analysis of vertical migration

Diel vertical migration of zooplankton is influenced by a variety of factors including predation, food, and temperature. Research has recently shifted from a focus on factors influencing migration to how migration affects nutrient cycling and habitat coupling. Here we evaluate the potential for Daphnia migrations to incorporate metalimnetic productivity in a well-studied northern...
Authors
Chase Julian Brosseau, Timothy J. Cline, Jonathan J. Cole, James R. Hodgson, Michael L. Pace, Brian Weidel
By
Ecosystems Mission Area, Great Lakes Science Center

Non-USGS Publications**

Cline, T.J., Ohlberger, J., and Schindler, D.E., 2019, Effects of warming climate and competition in the ocean for life-histories of Pacific salmon: Nature Ecology & Evolution, v. 3, p. 935–942.
Cline, T.J., Schindler, D.E., Hilborn, R., 2017, Fisheries portfolio diversification and turnover buffer Alaskan fishing communities from abrupt resource and market changes: Nature Communications, v: 8, 14042.
Brennan, S.R., Schindler, D.E., Cline, T.J., Walsworth, T.E., Buck, G., and Fernandez, D.P, 2019, Shifting habitat mosaics and fish production across river basins: Science, v. 364, p. 783–786.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

Translating the Relevance of USGS Science to Trout Unlimited’s Conservation and Engagement Work

Scientists with the USGS and Trout Unlimited (TU) recently hosted an event to facilitate cross-organizational learning and collaborative...

Read Article

Science and Products

Native Westslope Cutthroat Trout

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...
By
Climate Adaptation Science Centers
Assessing the Vulnerability of Native Trout in the Northern Rockies: Linking Science and Management for Climate Adaptation

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
Learn More

Climate change vulnerability of Arctic char across Scandinavia Climate change vulnerability of Arctic char across Scandinavia

Climate change is anticipated to cause species to shift their ranges upward and poleward, yet space for tracking suitable habitat conditions may be limited for range-restricted species at the highest elevations and latitudes of the globe. Consequently, range-restricted species inhabiting Arctic freshwater ecosystems, where global warming is most pronounced, face the challenge of coping...
Authors
Clint C. Muhlfeld, Timothy Cline, Anders Finstad, Dag O. Hessen, Sam Perrin, Jens Thaulow, Diane Whited, Leif Asbjorn Vollestad
By
Ecosystems Mission Area, Northern Rocky Mountain Science Center

Declines in body size of sockeye salmon associated with increased competition in the ocean Declines in body size of sockeye salmon associated with increased competition in the ocean

Declining body sizes have been documented for several species of Pacific salmon; however, whether size declines are caused mainly by ocean warming or other ecological factors, and whether they result primarily from trends in age at maturation or changing growth rates remain poorly understood. We quantified changes in mean body size and contributions from shifting size-at-age and age...
Authors
Jan Ohlberger, Timothy Joseph Cline, Daniel Schindler, Bert Lewis
By
Ecosystems Mission Area, Northern Rocky Mountain Science Center

High dispersal rates in hybrids drive expansion of maladaptive hybridization High dispersal rates in hybrids drive expansion of maladaptive hybridization

Hybridization between native and invasive species, a major cause of biodiversity loss, can spread rapidly even when hybrids have reduced fitness. This paradox suggests that hybrids have greater dispersal rates than non-hybridized individuals, yet this mechanism has not been empirically tested in animal populations. Here, we test if non-native genetic introgression increases reproductive...
Authors
Samuel Bourret, Ryan P. Kovach, Timothy Joseph Cline, Jeffrey Strait, Clint C. Muhlfeld
By
Ecosystems Mission Area, Northern Rocky Mountain Science Center

Socioeconomic resilience to climatic extremes in a freshwater fishery Socioeconomic resilience to climatic extremes in a freshwater fishery

Heterogeneity is a central feature of ecosystem resilience, but how this translates to socioeconomic resilience depends on people’s ability to track shifting resources in space and time. Here, we quantify how climatic extremes have influenced how people (fishers) track economically valuable ecosystem services (fishing opportunities) across a range of spatial scales in rivers of the...
Authors
Timothy Joseph Cline, Clint C. Muhlfeld, Ryan P. Kovach, Robert Al-Chokhachy, David Schmetterling, Diane Whited, Abigail Lynch
By
Ecosystems Mission Area, Climate Adaptation Science Centers, Northern Rocky Mountain Science Center

Stream size, temperature, and density explain body sizes of freshwater salmonids across a range of climate conditions Stream size, temperature, and density explain body sizes of freshwater salmonids across a range of climate conditions

Climate change and anthropogenic activities are altering the body sizes of fishes, yet our understanding of factors influencing body size for many taxa remains incomplete. We evaluated the relationships between climate, environmental, and landscape attributes and the body size of different taxa of freshwater trout (Salmonidae) in the USA. Hierarchical spatial modeling across a gradient...
Authors
Robert K. Al-Chokhachy, Benjamin Letcher, Clint C. Muhlfeld, Jason B. Dunham, Timothy Joseph Cline, Nathaniel P. Hitt, James Roberts, David Schmetterling
By
Ecosystems Mission Area, Fort Collins Science Center, Eastern Ecological Science Center, Northern Rocky Mountain Science Center

A framework to integrate innovations in invasion science for proactive management A framework to integrate innovations in invasion science for proactive management

Invasive alien species (IAS) are a rising threat to biodiversity, national security, and regional economies, with impacts in the hundreds of billions of U.S. dollars annually. Proactive or predictive approaches guided by scientific knowledge are essential to keeping pace with growing impacts of invasions under climate change. Although the rapid development of diverse technologies and...
Authors
Charles B. van Rees, Brian K. Hand, Sean C. Carter, Charles Bargeron, Timothy Joseph Cline, Wesley M. Daniel, Jason A. Ferrante, Keith Gaddis, Margaret E. Hunter, Catherine S. Jarnevich, Melodie A. McGeoch, Jeffrey T. Morisette, Matthew E. Neilson, Helen E. Roy, Mary Ann Rozance, Adam Sepulveda, Rebekah D. Wallace, Diane Whited, Taylor Wilcox, John S. Kimball, Gordon Luikart
By
Ecosystems Mission Area, Fort Collins Science Center, Northern Rocky Mountain Science Center, Wetland and Aquatic Research Center

Climate change and expanding invasive species drive widespread declines of native trout in the northern Rocky Mountains, USA Climate change and expanding invasive species drive widespread declines of native trout in the northern Rocky Mountains, USA

Climate change and invasive species are major threats to native biodiversity, but few empirical studies have examined their combined effects at large spatial and temporal scales. Using 21,917 surveys collected over 30 years, we quantified the impacts of climate change on the past and future distributions of five interacting native and invasive trout species throughout the northern Rocky...
Authors
Donovan A. Bell, Ryan P. Kovach, Clint C. Muhlfeld, Robert Al-Chokhachy, Timothy Joseph Cline, Diane C. Whited, David Schmetterling, Paul M Lukacs, Andrew R. Whiteley
By
Ecosystems Mission Area, Northern Rocky Mountain Science Center

Specialized meltwater biodiversity persists despite widespread deglaciation 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 region, primarily due to a lack of...
Authors
Clint C. Muhlfeld, Timothy Joseph Cline, J. Joseph Giersch, Erich Peitzsch, Caitlyn Florentine, Dean Jacobsen, Scott Hotaling
By
Ecosystems Mission Area, Ecosystems Land Change Science Program, Northern Rocky Mountain Science Center

Do Daphnia use metalimnetic organic matter in a north temperate lake? An analysis of vertical migration Do Daphnia use metalimnetic organic matter in a north temperate lake? An analysis of vertical migration

Diel vertical migration of zooplankton is influenced by a variety of factors including predation, food, and temperature. Research has recently shifted from a focus on factors influencing migration to how migration affects nutrient cycling and habitat coupling. Here we evaluate the potential for Daphnia migrations to incorporate metalimnetic productivity in a well-studied northern...
Authors
Chase Julian Brosseau, Timothy J. Cline, Jonathan J. Cole, James R. Hodgson, Michael L. Pace, Brian Weidel
By
Ecosystems Mission Area, Great Lakes Science Center

Non-USGS Publications**

Cline, T.J., Ohlberger, J., and Schindler, D.E., 2019, Effects of warming climate and competition in the ocean for life-histories of Pacific salmon: Nature Ecology & Evolution, v. 3, p. 935–942.
Cline, T.J., Schindler, D.E., Hilborn, R., 2017, Fisheries portfolio diversification and turnover buffer Alaskan fishing communities from abrupt resource and market changes: Nature Communications, v: 8, 14042.
Brennan, S.R., Schindler, D.E., Cline, T.J., Walsworth, T.E., Buck, G., and Fernandez, D.P, 2019, Shifting habitat mosaics and fish production across river basins: Science, v. 364, p. 783–786.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

Translating the Relevance of USGS Science to Trout Unlimited’s Conservation and Engagement Work

Scientists with the USGS and Trout Unlimited (TU) recently hosted an event to facilitate cross-organizational learning and collaborative...

Read Article
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