Actionable science to inform decision makers, managers, and the public
Professional Experience
2017 - Present Center Director, USGS Alaska Science Center, Anchorage, Alaska
2015 - 2017 Chief, Water and Interdisciplinary Studies Office, USGS, Alaska Science Center, Anchorage, Alaska
2002 - Present Chair Scientific and Technical Committee, Arctic-Yukon-Kuskokwim Sustainable Salmon Initiative, Anchorage, Alaska
2000 - 2001 Scientist, University of Washington, Seattle, Washington
1995 - 1997 Fishery Biologist, U.S. Forest Service Pacific Northwest Research Station, Corvallis, Oregon
1993 - 1995 Graduate Research Assistant, Oregon State University, Corvallis, Oregon
1992 Fishery Biologist, Thomas R. Payne and Associates/Pacific Land and Water Resources Consultants, Arcata, California
1991 Teaching Assistant, Humboldt State University, Arcata, California
1990 - 1991 Research Assistant, Institute of Limnology, Uppsala University, Uppsala, Sweden
1989 - 1990 Biological Technician, Redwood National Park, Arcata, California
Education and Certifications
Ph.D. 2000 Oregon State University, Corvallis, OR Fishery Science
M.S. 1996 Oregon State University, Corvallis, OR Fishery Science
B.S. 1992 Humboldt State University, Arcata, CA Fishery Biology
Affiliations and Memberships
American Fisheries Society
American Institute of Research Fishery Biologists - Fellow and Alaska District Director
Society for Freshwater Science
Science and Products
First juvenile Chum Salmon confirms successful reproduction for Pacific salmon in the North American Arctic
Premature mortality observations among Alaska’s Pacific salmon during record heat and drought in 2019
Migration strategies supporting salmonids in Arctic Rivers: A case study of Arctic Cisco and Dolly Varden
USGS permafrost research determines the risks of permafrost thaw to biologic and hydrologic resources
Interaction between watershed features and climate forcing affects habitat profitability for juvenile salmon
A manipulative thermal challenge protocol for adult salmonids in remote field settings
Transcriptomic response to elevated water temperatures in adult migrating Yukon River Chinook salmon (Oncorhynchus tshawytscha)
Evidence of prevalent heat stress in Yukon River Chinook salmon
Diversity of diatoms, benthic macroinvertebrates, and fish varies in response to different environmental correlates in Arctic rivers across North America
Lake trout growth is sensitive to spring temperature in southwest Alaska lakes
Fish growth rates and lake sulphate explain variation in mercury levels in ninespine stickleback (Pungitius pungitius) on the Arctic Coastal Plain of Alaska
Surface water connectivity controls fish food web structure and complexity across local- and meta-food webs in Arctic Coastal Plain lakes
Outer Continental Shelf Program
Science Support Program and Quick Response Program
Natural Resources Preservation Program
Collaborative Science for Priority Information Needs
Arctic Lake Food Webs
Ecosystem Shifts in Arctic Seas
Lake Trout Biochronologies as Long-term Climate and Productivity Indicators in Alaska Lake Ecosystems
Primary Production Sources and Bottom-up Limitations in Nearshore Ecosystems
Hydro-Ecology of Arctic Thawing (HEAT): Ecology
Effect of Elodea spp. on Fish Performance Mediated Through Food Web Interactions
Sockeye Salmon Migrating at the Northern Edge of Their Distribution
Assessing heat stress in migrating Yukon River Chinook Salmon
Science and Products
- Publications
Filter Total Items: 64
First juvenile Chum Salmon confirms successful reproduction for Pacific salmon in the North American Arctic
The distributional extent of Pacific salmon Oncorhynchus spp. in the North American Arctic is unresolved. While adult Pacific salmon have a recurring presence across the Alaskan North Slope and into the Canadian Arctic, it is uncertain if these fish are part of established Arctic populations, vagrants from outside sources reproducing unsuccessfully, or both. Here we present the first confirmed recPremature mortality observations among Alaska’s Pacific salmon during record heat and drought in 2019
Widespread mortality of Pacific salmon Oncorhynchus spp. returning to spawn in Alaska coincided with record-breaking air temperatures and prolonged drought in summer 2019. Extreme environmental conditions are expected to happen more frequently with rapid climate change and challenge the notion that Alaska could indefinitely provide abundant, cool freshwater habitat for Pacific salmon. A total of 1Migration strategies supporting salmonids in Arctic Rivers: A case study of Arctic Cisco and Dolly Varden
Amphidromous fish such as Dolly Varden (Salvelinus malma) and Arctic Cisco (Coregonus autumnalis) have distinct life histories that facilitate their success in Arctic environments. Both species spawn in freshwater and make annual migrations between marine, brackish, or freshwater environments. Dolly Varden rear for one or more years in freshwater before migrating to sea whereas Arctic Cisco migratUSGS permafrost research determines the risks of permafrost thaw to biologic and hydrologic resources
The U.S. Geological Survey (USGS), in collaboration with university, Federal, Tribal, and independent partners, conducts fundamental research on the distribution, vulnerability, and importance of permafrost in arctic and boreal ecosystems. Scientists, land managers, and policy makers use USGS data to help make decisions for development, wildlife habitat, and other needs. Native villages and citiesByNatural Hazards, Water Resources, Climate Research and Development Program, Coastal and Marine Hazards and Resources Program, Earth Resources Observation and Science Center, Land Change Science Program, Volcano Hazards, Volcano Science Center, Earth Resources Observation and Science (EROS) Center , Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center, Pacific Coastal and Marine Science CenterInteraction between watershed features and climate forcing affects habitat profitability for juvenile salmon
Opportunities for growth and survival of aquatic organisms are spatially and temporally variable as habitat conditions across watersheds respond to interacting climatic, geomorphic, and hydrologic conditions. As conservation efforts often focus on identifying and protecting critical habitats, it is important to understand how this spatial and temporal variation in habitat quality affects the produA manipulative thermal challenge protocol for adult salmonids in remote field settings
Manipulative experiments provide stronger evidence for identifying cause-and-effect relationships than correlative studies, but protocols for implementing temperature manipulations are lacking for large species in remote settings. We developed an experimental protocol for holding adult Chinook salmon (Oncorhynchus tshawytscha) and exposing them to elevated temperature treatments. The goal of the eTranscriptomic response to elevated water temperatures in adult migrating Yukon River Chinook salmon (Oncorhynchus tshawytscha)
Chinook salmon (Oncorhynchus tshawytscha) declines are widespread and may be attributed, at least in part, to warming river temperatures. Water temperatures in the Yukon River and tributaries often exceed 18°C, a threshold commonly associated with heat stress and elevated mortality in Pacific salmon. Untangling the complex web of direct and indirect physiological effects of heat stress on salmon iEvidence of prevalent heat stress in Yukon River Chinook salmon
Migrating adult Pacific salmon (Oncorhynchus spp.) are sensitive to warm water (>18 °C), with a range of consequences from decreased spawning success to early mortality. We examined the proportion of Yukon River Chinook salmon (O. tshawytscha) exhibiting evidence of heat stress to assess the potential that high temperatures contribute to freshwater adult mortality in a northern Pacific salmon popuDiversity of diatoms, benthic macroinvertebrates, and fish varies in response to different environmental correlates in Arctic rivers across North America
Climate change poses a significant threat to Arctic freshwater biodiversity, but impacts depend upon the strength of organism response to climate‐related drivers. Currently, there is insufficient knowledge about Arctic freshwater biodiversity patterns to guide assessment, prediction, and management of biodiversity change.As part of the Circumpolar Biodiversity Monitoring Program's first freshwaterLake trout growth is sensitive to spring temperature in southwest Alaska lakes
In high‐latitude lakes, air temperature is an important driver of ice cover thickness and duration, which in turn influence water temperature and primary production supporting lake consumers and predators. In lieu of multidecadal observational records necessary to assess the response of lakes to long‐term warming, we used otolith‐based growth records from a long‐lived resident lake fish, lake trouFish growth rates and lake sulphate explain variation in mercury levels in ninespine stickleback (Pungitius pungitius) on the Arctic Coastal Plain of Alaska
Mercury concentrations in freshwater food webs are governed by complex biogeochemical and ecological interactions that spatially vary and are often mediated by climate. The Arctic Coastal Plain of Alaska (ACP) is a heterogeneous, lake-rich landscape where variability in mercury accumulation is poorly understood. Earlier research indicated that the level of catchment influence on lakes varied spatiSurface water connectivity controls fish food web structure and complexity across local- and meta-food webs in Arctic Coastal Plain lakes
The need for theories that address food web assembly and complexity over multiple spatial scales are critical to understanding their stability and persistence. In a meta-food web – an integrated network of local food webs – spatial heterogeneity in physical processes may have profound effects on food web function and energy flow. In the Arctic, surface water connectivity plays a vital role in dete - Science
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Outer Continental Shelf Program
This is a nation-wide collaborative program, supported by the USGS Ecosystems Mission Area, through which USGS and Bureau of Ocean Energy Management staff address priority research needs identified by the Bureau of Ocean Energy Management. On this page, we highlight research taking place in Alaska as part of this program.Science Support Program and Quick Response Program
This is a nation-wide collaborative program, supported by the USGS Ecosystems Mission Area, through which USGS and U.S. Fish and Wildlife Service staff address priority research needs identified by the U.S. Fish and Wildlife Service. On this page, we highlight research taking place in Alaska as part of this program.Natural Resources Preservation Program
This is a nation-wide collaborative program, supported by the USGS Ecosystems Mission Area, through which USGS and National Park Service staff address priority research needs identified by the National Park Service. On this page, we highlight research taking place in Alaska as part of this program.Collaborative Science for Priority Information Needs
One of the primary missions of the USGS is to address the science needs of Department of Interior bureaus, particularly those that manage natural resources and lands. This mission is fulfilled through the research and other activities of USGS scientists but also specifically through three USGS nationally-funded programs listed below.Arctic Lake Food Webs
From 2011 to 2013 we investigated freshwater food webs of Arctic Coastal Plain lakes in Alaska to improve our understanding how Arctic freshwater food webs may respond to landscape change the warmer, drier future.Ecosystem Shifts in Arctic Seas
In addition to the direct effects of sea ice loss on walrus (Odobenus rosmarus divergens) and polar bears (Ursus maritimus) that use ice as a platform, the decline of Arctic sea ice is predicted to promote a fundamental ecosystem shift from benthic animals that forage on the sea floor to pelagic animals that forage near the sea surface.Lake Trout Biochronologies as Long-term Climate and Productivity Indicators in Alaska Lake Ecosystems
High latitude ecosystems are among the most vulnerable to long-term climate change, yet continuous, multidecadal indicators by which to gauge effects on biology are scarce, especially in freshwater environments.Primary Production Sources and Bottom-up Limitations in Nearshore Ecosystems
Kelp forests are among the world’s most productive habitats, but recent evidence suggests that production is highly variable.Hydro-Ecology of Arctic Thawing (HEAT): Ecology
Permafrost thaw is leading to a myriad of changes in physical and chemical conditions throughout the Arctic.Effect of Elodea spp. on Fish Performance Mediated Through Food Web Interactions
The potential for invasive species introductions in Arctic and Subarctic ecosystems is growing as climate change manifests and human activity increases in high latitudes.Sockeye Salmon Migrating at the Northern Edge of Their Distribution
The physiological challenge for anadromous fish to migrate upriver to spawn and complete their life cycle is influenced by river temperature.Assessing heat stress in migrating Yukon River Chinook Salmon
We will examine evidence of heat stress in Yukon River Chinook salmon (Oncorhynchus tshawytscha) using heat shock proteins and gene expression.