Permafrost thaw is leading to a myriad of changes in physical and chemical conditions throughout the Arctic.
Return to Ecosystems or Water >> Fish and Aquatic Ecology
Permafrost thaw and the subsequent changes to geomorpholgy, hydrology, and vegetation can alter groundwater flow and inflows to streams, affecting river hydrographs, water temperature, and the availability of carbon and nutrients. Changes in stream hydrology and chemistry subsequently have the potential to affect fish habitat and metabolism directly. By changing primary productivity in stream ecosystems, these changes can also alter food resources available to fish. While these physical changes have already been observed in interior Alaska there is little understanding of the effects on ecosystems and Alaska’s fish that are important commercial, sport, and subsistence resources, and also important to wildlife. This 5 year study will assess the potential effects of permafrost thaw on streams and their fish by 1) using space for time approaches to consider the effects of permafrost loss (through thermokarsting and decreased permafrost extent) on stream hydrology and chemistry, ecosystem functions, fish performance, and fish community structure; 2) using physical models to determine the rates of change and explore potential effects on stream discharge, temperature, hyporheic zones, flow duration, perennial stream lengths, and inflows; and 3) using a temperature-based combined physical and fish metabolism model to quantify the effects for Dolly Varden (Salvelinus malma) and Arctic Grayling (Thymallus arcticus). These will provide major advances in our understanding of hydrology and fish at the boreal-arctic transition, as well as a direct link (through stream temperature) to couple climate change and fish metabolism. This glimpse into Alaska’s future has broad implications for understanding the rates and mechanisms of landscape change, with implications for these two fish species as well as the broader fish community. This research program will inform management decisions on development activities and enable predictions on the effects of climate change for wildlife outcomes.
This project is in conjunction with the Hydro-ecology of Arctic Thawing: Hydrology
Funding: USGS Changing Arctic Ecosystem Initiative



Below are other science projects associated with this project.
Fish and Aquatic Ecology
Condition of Forage Fish in Prince William Sound During the Marine Heatwave
Winter Habitat of Juvenile Dolly Varden in the Canning River
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
Effect of Elodea spp. on Fish Performance Mediated Through Food Web Interactions
Sockeye Salmon Migrating at the Northern Edge of Their Distribution
Nearshore Fish Surveys in the Beaufort Sea
Assessing heat stress in migrating Yukon River Chinook Salmon
Hydro-Ecology of Arctic Thawing (HEAT): Hydrology
Below are multimedia items associated with this project.
- Overview
Permafrost thaw is leading to a myriad of changes in physical and chemical conditions throughout the Arctic.
Return to Ecosystems or Water >> Fish and Aquatic Ecology
Permafrost thaw and the subsequent changes to geomorpholgy, hydrology, and vegetation can alter groundwater flow and inflows to streams, affecting river hydrographs, water temperature, and the availability of carbon and nutrients. Changes in stream hydrology and chemistry subsequently have the potential to affect fish habitat and metabolism directly. By changing primary productivity in stream ecosystems, these changes can also alter food resources available to fish. While these physical changes have already been observed in interior Alaska there is little understanding of the effects on ecosystems and Alaska’s fish that are important commercial, sport, and subsistence resources, and also important to wildlife. This 5 year study will assess the potential effects of permafrost thaw on streams and their fish by 1) using space for time approaches to consider the effects of permafrost loss (through thermokarsting and decreased permafrost extent) on stream hydrology and chemistry, ecosystem functions, fish performance, and fish community structure; 2) using physical models to determine the rates of change and explore potential effects on stream discharge, temperature, hyporheic zones, flow duration, perennial stream lengths, and inflows; and 3) using a temperature-based combined physical and fish metabolism model to quantify the effects for Dolly Varden (Salvelinus malma) and Arctic Grayling (Thymallus arcticus). These will provide major advances in our understanding of hydrology and fish at the boreal-arctic transition, as well as a direct link (through stream temperature) to couple climate change and fish metabolism. This glimpse into Alaska’s future has broad implications for understanding the rates and mechanisms of landscape change, with implications for these two fish species as well as the broader fish community. This research program will inform management decisions on development activities and enable predictions on the effects of climate change for wildlife outcomes.
This project is in conjunction with the Hydro-ecology of Arctic Thawing: Hydrology
Funding: USGS Changing Arctic Ecosystem Initiative
Dolly Varden from the Agashashok River on a measuring board.(Credit: Mike Carey, USGS. Public domain.) Dolly Varden in a minnow trap in the Agashashok River drainage. (Credit: Mike Carey, USGS. Public domain.) Sculpin in shallow water in the Agashashok River watershed.(Credit: Mike Carey, USGS. Public domain.) Sources/Usage: Public Domain. Visit Media to see details.Small arctic grayling hugging the bottom in the Imelyak River in the Brooks Range. (Credit: Mike Carey, USGS. Public domain.) Underwater photo of a large school of Dolly Varden char and Arctic grayling in the Agashashok River. (Credit: Mike Records, USGS. Public domain.) A stream type at the Boreal-Arctic transition of the Brooks Range, Noatak National Park and Preserve, Kobuk Valley National Park. The stream is part of the Agashashok River watershed. (Credit: Mike Carey, USGS. Public domain.) A stream type at the Boreal-Arctic transition of the Brooks Range, Noatak National Park and Preserve, Kobuk Valley National Park. The stream is in the Agashashok River watershed.(Credit: Mike Carey, USGS. Public domain.) A stream type at the Boreal-Arctic transition of the Brooks Range, Noatak National Park and Preserve, Kobuk Valley National Park. This stream is in the Agashashok River watershed. (Credit: Mike Carey, USGS. Public domain.) A stream type at the Boreal-Arctic transition of the Brooks Range, Noatak National Park and Preserve, Kobuk Valley National Park. The stream is in the Agashashok River watershed. (Credit: Mike Carey, USGS. Public domain.) Sources/Usage: Public Domain. Visit Media to see details.Hiking up a stream from the Akilik River drainage to set minnow traps for fish sampling. This is a stream type at the Boreal-Arctic transition of the Brooks Range, Noatak National Park and Preserve, Kobuk Valley National Park.(Credit: Josh Koch, USGS. Public domain.) A snorkeler sampling a stream in the Boreal-Arctic transition of the Brooks Range in Noatak National Park and Preserve, Kobuk Valley National Park.(Credit: Mike Carey, USGS. Public domain.) Sampling the Imelyak River in the Boreal-Arctic transition of the Brooks Range in Noatak National Park and Preserve, Kobuk Valley National Park.(Credit: Mike Carey, USGS. Public domain.) Chris Zimmerman sampling a stream in the drainage of the Agashashok River which is in the Boreal-Arctic transition of the Brooks Range in Noatak National Park and Preserve, Kobuk Valley National Park. (Credit: Mike Carey, USGS. Public domain.) Sources/Usage: Public Domain. Visit Media to see details.Sampling a stream from the Akilik River drainage in the Boreal-Arctic transition of the Brooks Range in Noatak National Park and Preserve, Kobuk Valley National Park. (Credit: Mike Carey, USGS. Public domain.) - Science
Below are other science projects associated with this project.
Fish and Aquatic Ecology
Fish and aquatic habitats in Alaska support important commercial, sport, and subsistence fisheries and provide forage fish that support wildlife populations. The USGS Alaska Science Center conducts interdisciplinary research to inform local, state, federal, and international policy makers regarding conservation of fish, aquatic species, and their habitats. We work collaboratively with hydrologists...Condition of Forage Fish in Prince William Sound During the Marine Heatwave
Changes in the body condition of a key forage fish species, Pacific sand lance (Ammodytes personatus), are examined to understand how energy transfer to predators may have been disrupted during the recent marine heatwave in the North Pacific (late 2013 to mid 2016).Winter Habitat of Juvenile Dolly Varden in the Canning River
In the Arctic, rivers often freeze all the way to the bottom each winter leaving fish with limited habitat where they can survive.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.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.Nearshore Fish Surveys in the Beaufort Sea
Nearshore systems provide habitat to a unique community of marine and diadromous (lives in both fresh and saltwater) fish and support high fish abundance.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.Hydro-Ecology of Arctic Thawing (HEAT): Hydrology
The Arctic is warming at higher rates than much of the rest of the world. For Alaska, this results in changes in hydrology and ecosystems – permafrost is thawing, changing landscapes and releasing nutrients to soils and streams. - Multimedia
Below are multimedia items associated with this project.