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 U.S. Endangered Species Act. Complicating these stressors is global warming and associated climate change. Overall, aquatic ecosystems across the PNW are predicted to experience increasingly earlier snowmelt in the spring, reduced late spring and summer flows, increased winter flooding, warmer and drier summers, increased water temperatures, and expansion of invasive species. Understanding how the effects of climate change might influence habitat for native salmonid populations is critical for effective management and recovery of these species.
Scientists at the USGS and University of Montana are using novel modeling techniques and empirical data to study how climate change may drive landscape scale impacts that affect freshwater habitats and populations of key salmonid species (bull trout, cutthroat trout, and steelhead) throughout the PNW. Results show strong linkages between climatic drivers – temperature and flow regimes – and the distribution, abundance and genetic diversity of native salmonids across the PNW. Specifically, warming temperatures and shifting flow regimes are expected to fragment stream systems and cause salmonids to retreat upstream to headwater areas, thereby decreasing fish population abundance and genetic diversity – both of which are critical for persistence in a changing landscape. Climate-change-induced periods of decreasing spring snowmelt and increases in stream temperatures are likely to decrease native biodiversity by fostering cross-breeding between invasive and native trout species. The study is also developing new frameworks for assessing the vulnerability of multiple freshwater species to climate change and other stressors in complex stream networks, which will aid managers in pro-actively implementing conservation programs to increase resiliency and adaptive capacity of aquatic species. Finally, results of this project are helping to improve the Riverscape Analysis Project (RAP; http://rap.ntsg.umt.edu), which offers a new and powerful web-based platform to aid conservation practitioners with assessing the vulnerability of species under climate change.
Funding: USGS Northwest Climate Science Center
Collaborators: University of Montana (Drs. Gordon Luikart, Brian Hand, and Alisa Wade)
Below are publications associated with this project.
Climate variables explain neutral and adaptive variation within salmonid metapopulations: The importance of replication in landscape genetics
Genetic diversity is related to climatic variation and vulnerability in threatened bull trout
Combining demographic and genetic factors to assess population vulnerability in stream species
Invasive hybridization in a threatened species is accelerated by climate change
Below are partners associated with this project.
- Overview
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 U.S. Endangered Species Act. Complicating these stressors is global warming and associated climate change. Overall, aquatic ecosystems across the PNW are predicted to experience increasingly earlier snowmelt in the spring, reduced late spring and summer flows, increased winter flooding, warmer and drier summers, increased water temperatures, and expansion of invasive species. Understanding how the effects of climate change might influence habitat for native salmonid populations is critical for effective management and recovery of these species.
Scientists at the USGS and University of Montana are using novel modeling techniques and empirical data to study how climate change may drive landscape scale impacts that affect freshwater habitats and populations of key salmonid species (bull trout, cutthroat trout, and steelhead) throughout the PNW. Results show strong linkages between climatic drivers – temperature and flow regimes – and the distribution, abundance and genetic diversity of native salmonids across the PNW. Specifically, warming temperatures and shifting flow regimes are expected to fragment stream systems and cause salmonids to retreat upstream to headwater areas, thereby decreasing fish population abundance and genetic diversity – both of which are critical for persistence in a changing landscape. Climate-change-induced periods of decreasing spring snowmelt and increases in stream temperatures are likely to decrease native biodiversity by fostering cross-breeding between invasive and native trout species. The study is also developing new frameworks for assessing the vulnerability of multiple freshwater species to climate change and other stressors in complex stream networks, which will aid managers in pro-actively implementing conservation programs to increase resiliency and adaptive capacity of aquatic species. Finally, results of this project are helping to improve the Riverscape Analysis Project (RAP; http://rap.ntsg.umt.edu), which offers a new and powerful web-based platform to aid conservation practitioners with assessing the vulnerability of species under climate change.
Funding: USGS Northwest Climate Science Center
Collaborators: University of Montana (Drs. Gordon Luikart, Brian Hand, and Alisa Wade)
- Publications
Below are publications associated with this project.
Climate variables explain neutral and adaptive variation within salmonid metapopulations: The importance of replication in landscape genetics
Understanding how environmental variation influences population genetic structure is important for conservation management because it can reveal how human stressors influence population connectivity, genetic diversity and persistence. We used riverscape genetics modelling to assess whether climatic and habitat variables were related to neutral and adaptive patterns of genetic differentiation (popuAuthorsBrian K. Hand, Clint C. Muhlfeld, Alisa A. Wade, Ryan Kovach, Diane C. Whited, Shawn R. Narum, Andrew P. Matala, Michael W. Ackerman, B. A. Garner, John S Kimball, Jack A. Stanford, Gordon LuikartGenetic diversity is related to climatic variation and vulnerability in threatened bull trout
Understanding how climatic variation influences ecological and evolutionary processes is crucial for informed conservation decision-making. Nevertheless, few studies have measured how climatic variation influences genetic diversity within populations or how genetic diversity is distributed across space relative to future climatic stress. Here, we tested whether patterns of genetic diversity (allelAuthorsRyan Kovach, Clint C. Muhlfeld, Alisa A. Wade, Brian K. Hand, Diane C. Whited, Patrick W. DeHaan, Robert K. Al-Chokhachy, Gordon LuikartCombining demographic and genetic factors to assess population vulnerability in stream species
Accelerating climate change and other cumulative stressors create an urgent need to understand the influence of environmental variation and landscape features on the connectivity and vulnerability of freshwater species. Here, we introduce a novel modeling framework for aquatic systems that integrates spatially explicit, individual‐based, demographic and genetic (demogenetic) assessments with envirAuthorsErin L. Landguth, Clint C. Muhlfeld, Leslie W. Jones, Robin S. Waples, Diane Whited, Winsor H. Lowe, John Lucotch, Helen Neville, Gordon LuikartInvasive hybridization in a threatened species is accelerated by climate change
Climate change will decrease worldwide biodiversity through a number of potential pathways1, including invasive hybridization2 (cross-breeding between invasive and native species). How climate warming influences the spread of hybridization and loss of native genomes poses difficult ecological and evolutionary questions with little empirical information to guide conservation management decisions3.AuthorsClint C. Muhlfeld, Ryan P. Kovach, Leslie A. Jones, Robert K. Al-Chokhachy, Matthew C. Boyer, Robb F. Leary, Winsor H. Lowe, Gordon Luikart, Fred W. Allendorf - Partners
Below are partners associated with this project.