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Jeff Falke, PhD

Unit Leader - Alaska Cooperative Fish and Wildlife Research Unit 

Research Interests

  • Freshwater fish ecology and conservation biology;
  • Ecology and evolutionary biology of salmonids;
  • Landscape and spatial ecology of freshwater ecosystems;
  • Climate change impacts on aquatic systems;
  • Impacts of introduced species on native aquatic fauna

Teaching Interests

Freshwater fish ecology

Professional Experience

  • Unit Leader, Alaska Cooperative Fish and Wildlife Research Unit, 2019-

  • Assistant Unit Leader, Alaska Cooperative Fish and Wildlife Research Unit, 2012-2019

Education and Certifications

  • Ph D Colorado State University 2009

  • MS Kansas State University 2004

  • BS University of Missouri 2000

Science and Products

Filter Total Items: 32

Reducing uncertainty in climate change responses of inland fishes: A decision-path approach

Climate change will continue to be an important consideration for conservation practitioners. However, uncertainty in identifying appropriate management strategies, particularly for understudied species and regions, constrains the implementation of science-based solutions and adaptation strategies. Here, we share a decision-path approach to reduce uncertainty in climate change responses of inland
By
Ecosystems Mission Area, Climate Adaptation Science Centers

Climate change effects on North American fish and fisheries to inform adaptation strategies

Climate change is a global persistent threat to fish and fish habitats throughout North America. Climate-induced modification of environmental regimes, including changes in streamflow, water temperature, salinity, storm surges, and habitat connectivity can change fish physiology, disrupt spawning cues, cause fish extinctions and invasions, and alter fish community structure. Reducing greenhouse em
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Ecosystems Mission Area, Climate Adaptation Science Centers

Assessing potential stock structure of adult Coho Salmon in a small Alaska watershed: Quantifying run timing, spawning locations, and holding areas with radiotelemetry

Run timing and spatial locations of spawning habitats are often used to identify stocks for conservation planning or management of salmonid fishes. Although complex stock structure is most common within large watersheds with diverse habitats, even small drainages can produce multiple co-occurring spatially or temporally isolated populations or “stocks.” This project sought to address the potential
By
Cooperative Research Units

High-resolution remote sensing and multistate occupancy estimation identify drivers of spawning site selection in fall chum salmon (Oncorhynchus keta) across a sub-Arctic riverscape

Groundwater upwellings provide warmer, stable overwinter temperatures for developing salmon embryos, which may be particularly important in cold, braided, gravel-bed sub-Arctic rivers. We used a three-year time series of aerial counts and remote sensing to estimate the distribution of low and high aggregations of spawning fall chum salmon (Oncorhynchus keta), classify approximately 0.5 km long riv
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Cooperative Research Units

Vulnerability of Pacific salmon to invasion of northern pike (Esox lucius) in Southcentral Alaska

The relentless role of invasive species in the extinction of native biota requires predictions of ecosystem vulnerability to inform proactive management strategies. The worldwide invasion and range expansion of predatory northern pike (Esox lucius) has been linked to the decline of native fishes and tools are needed to predict the vulnerability of habitats to invasion over broad geographic scales.
By
Ecosystems Mission Area, Cooperative Research Units, Northern Rocky Mountain Science Center

Determinants of gray wolf (Canis lupus) sightings in Denali National Park

Wildlife viewing within protected areas is an increasingly popular recreational activity. Management agencies are often tasked with providing these opportunities, yet quantitative analyses of factors influencing wildlife sightings are lacking. We analyzed locations of GPS-collared wolves and wolf sightings from 2945 trips in Denali National Park and Preserve, Alaska, USA, to provide a mechanistic
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Cooperative Research Units

FiCli, the Fish and Climate Change Database, informs climate adaptation and management for freshwater fishes

Inland fishes provide important ecosystem services to communities worldwide and are especially vulnerable to the impacts of climate change. Fish respond to climate change in diverse and nuanced ways, which creates challenges for practitioners of fish conservation, climate change adaptation, and management. Although climate change is known to affect fish globally, a comprehensive online, public dat
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Ecosystems Mission Area, Climate Adaptation Science Centers, Cooperative Research Units

Thermal diversity of salmon streams in the Matanuska-Susitna Basin, Alaska

We present the first description of summer stream thermal regimes in Alaska using metrics that represent the magnitude, variability, frequency, duration, and timing of temperature events related to salmon life histories. We used cluster analysis to characterize thermal regimes present in the Matanuska-Susitna (Mat-Su) Basin based on 10 nonredundant temperature metrics and identified the most impor
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Cooperative Research Units

A classification of streamflow patterns across the coastal Gulf of Alaska

Streamflow controls many freshwater and marine processes, including salinity profiles, sediment composition, fluxes of nutrients, and the timing of animal migrations. Watersheds that border the Gulf of Alaska (GOA) comprise over 400,000 km2 of largely pristine freshwater habitats and provide ecosystem services such as reliable fisheries for local and global food production. Yet no comprehensive wa
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Cooperative Research Units

Energetic status of Alaskan Chinook Salmon: Interpopulation comparisons and predictive modeling using bioelectrical impedance analysis

Adult Pacific Salmon Oncorhynchus spp. undertake energetically demanding migrations wherein they must have adequate energy reserves to survive to spawning locations and reproduce. Proximate analysis provides insight into available energy stores (e.g., lipids), but the ability to non-lethally monitor energetic status may be useful for managers to better understand how energetic status affects salmo
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Cooperative Research Units

Climatic variation drives growth potential of juvenile Chinook Salmon (Oncorhynchus tshawytscha) along a sub-Arctic boreal riverscape

Climatic variation is a key driver of freshwater physical processes that in turn control stream fish growth and population dynamics at fine spatial scales and species distributions across broad landscapes. A recent downturn in Chinook Salmon returns across the Yukon River basin, Alaska, USA, and Yukon Territories, Canada, has led to hardship among user groups and increased interest in understandin
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Cooperative Research Units

Energetic status and bioelectrical impedance modeling of Arctic grayling Thymallus arcticus in interior Alaska Rivers

The energetic status of fishes represents energy stored as protein and lipids and reflects the ability of an individual to reproduce, migrate, and transition through life stages, ultimately influencing survival. However, traditional measurement methods, while highly accurate, are time consuming, expensive, and lethal, and nonlethal methods such as condition factor may not adequately characterize e
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Cooperative Research Units
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A boreal bog surrounded by grasses and plants with the sun setting in the background

Webinar: Aquatic Ecosystem Vulnerability to Fire and Climate Change in Alaskan Boreal Forests

View this webinar for more information about conservation efforts surrounding aquatic habitats in boreal Alaska.
By
Ecosystems Mission Area, Climate Adaptation Science Centers, Climate Adaptation Science Centers
link

Webinar: Aquatic Ecosystem Vulnerability to Fire and Climate Change in Alaskan Boreal Forests

View this webinar for more information about conservation efforts surrounding aquatic habitats in boreal Alaska.
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Data describing vulnerability of Pacific salmon to invasion of northern pike (Esox lucius) in southcentral Alaska, 2017-2019

The shapefile contains the data necessary to recreate the analyses used in Jalbert et al., in review, Vulnerability of Pacific salmon to invasion of northern pike (Esox lucius) in southcentral Alaska. Specifically, users will be able to view 1) intrinsic potential model calculations for 5 Pacific salmonids (Chinook, chum, pink, sockeye, and coho salmon) and northern pike and 2) all parent nodes of
By
Northern Rocky Mountain Science Center

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