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The water quality of streams and rivers in the Arctic is sensitive to rapid climate change and altered disturbance regimes.
Return to Ecosystems or Water >> Fish and Aquatic Ecology
Widespread permafrost thaw, thaw-induced erosion, and wildfires have altered the concentration and flux of organic carbon, nutrients, and trace metals in Arctic rivers. Subsequently, changes in surface waters can impact the habitability for biota and growth rates for fish.
Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw. One consequence of these altered iron-cycling processes is the abrupt change in color (orange) of stream and river reaches, reflecting a dramatic shift in water quality.
Although the exact mechanisms are yet to be determined, evidence indicates that shifting hydrological and oxidation-reduction processes associated with permafrost thaw may function to transport high concentrations of iron in dissolved and colloidal forms from thawing soils to streams.
Preliminary observations suggest that orange stream reaches have higher iron concentrations, less dissolved oxygen, and more acidic water than nearby clearwater streams. Further, the conversion of streams from clear to orange water appears to reflect a considerable deterioration of habitat for benthic macroinvertebrates and fish.
In 2022, a team of USGS and NPS researchers began working on this topic with the overall goal of defining and understanding changes to Arctic rivers in Alaska to meet conservation goals of the Department of the Interior. We are partnering with the University of California-Davis, University of Alaska-Anchorage, and Alaska Pacific University to address several research objectives including:
- Mapping the spatial distribution of orange streams and the onset of stream color change across national parks in the Arctic Inventory & Monitoring Network.
- Quantifying the effects of iron and other metal inputs on water quality in Arctic streams and determining landscape controls on metal mobilization.
- Identifying how geology, hydrology, and permafrost degradation are contributing to changes in the chemistry of Arctic rivers, with the goal to determine susceptibility and resilience to current and future changes.
- Assessing consequences of shifts in stream water quality on stream biota, including biofilm, macroinvertebrates, and resident fish communities.
Funding: USGS Changing Arctic Ecosystem Initiative and USGS-NPS Water Quality Partnership
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset. By sampling orange stream chemistry and assessing their spatial and temporal distribution we aim to 1) test multiple hypotheses related to their cause and link to warming and thawing landscapes, and 2) consider the implications for downstream water quality and ecosystems.
Recent observations from Arctic Alaska indicate that waters draining through thawing permafrost landscapes are mobilizing iron, carbon, and other heavy metals. These altered processes associated with thaw of permafrost is leading to abrupt changes in the color (orange) of stream and rivers, reflecting a dramatic shift in water quality. Change in water quality includes higher acidity and turbidity, and higher concentrations of sulfate, total iron, and trace metals, such as zinc and nickel. Stream discoloration has also been associated with declines in macroinvertebrate diversity and fish abundance. These findings may have implications for drinking water supplies and subsistence fisheries of rural Alaskan communities.
Deposition on tributary of Salmon River located in Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Deposition on tributary of Salmon River located in Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Tributary of Salmon River located in Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Tributary of Salmon River located in Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Tributary of Salmon River located in the Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Tributary of Salmon River located in the Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Iron seep on the North fork of the Agashashok River, Noatak National Park and Preserve, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Iron seep on the North fork of the Agashashok River, Noatak National Park and Preserve, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Map of orange stream observations across Arctic Inventory and Monitoring Network (ARCN) parks in northern Alaska.
Map of orange stream observations across Arctic Inventory and Monitoring Network (ARCN) parks in northern Alaska.
Tributary of Agashashok River located in the Noatak National Park and Preserve, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Tributary of Agashashok River located in the Noatak National Park and Preserve, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
North fork of the Agashashok River located in Noatak National Park and Preserve, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
North fork of the Agashashok River located in Noatak National Park and Preserve, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Impacts of iron mobilization in a stream tributary of the Akillik River located in Kobuk Valley National Park, Alaska. These images were taken two years apart. The clear picture was taken in June 2016 and the orange picture was August 2018.
Impacts of iron mobilization in a stream tributary of the Akillik River located in Kobuk Valley National Park, Alaska. These images were taken two years apart. The clear picture was taken in June 2016 and the orange picture was August 2018.
The water quality of streams and rivers in the Arctic is sensitive to rapid climate change and altered disturbance regimes.
Return to Ecosystems or Water >> Fish and Aquatic Ecology
Widespread permafrost thaw, thaw-induced erosion, and wildfires have altered the concentration and flux of organic carbon, nutrients, and trace metals in Arctic rivers. Subsequently, changes in surface waters can impact the habitability for biota and growth rates for fish.
Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw. One consequence of these altered iron-cycling processes is the abrupt change in color (orange) of stream and river reaches, reflecting a dramatic shift in water quality.
Although the exact mechanisms are yet to be determined, evidence indicates that shifting hydrological and oxidation-reduction processes associated with permafrost thaw may function to transport high concentrations of iron in dissolved and colloidal forms from thawing soils to streams.
Preliminary observations suggest that orange stream reaches have higher iron concentrations, less dissolved oxygen, and more acidic water than nearby clearwater streams. Further, the conversion of streams from clear to orange water appears to reflect a considerable deterioration of habitat for benthic macroinvertebrates and fish.
In 2022, a team of USGS and NPS researchers began working on this topic with the overall goal of defining and understanding changes to Arctic rivers in Alaska to meet conservation goals of the Department of the Interior. We are partnering with the University of California-Davis, University of Alaska-Anchorage, and Alaska Pacific University to address several research objectives including:
- Mapping the spatial distribution of orange streams and the onset of stream color change across national parks in the Arctic Inventory & Monitoring Network.
- Quantifying the effects of iron and other metal inputs on water quality in Arctic streams and determining landscape controls on metal mobilization.
- Identifying how geology, hydrology, and permafrost degradation are contributing to changes in the chemistry of Arctic rivers, with the goal to determine susceptibility and resilience to current and future changes.
- Assessing consequences of shifts in stream water quality on stream biota, including biofilm, macroinvertebrates, and resident fish communities.
Funding: USGS Changing Arctic Ecosystem Initiative and USGS-NPS Water Quality Partnership
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset. By sampling orange stream chemistry and assessing their spatial and temporal distribution we aim to 1) test multiple hypotheses related to their cause and link to warming and thawing landscapes, and 2) consider the implications for downstream water quality and ecosystems.
Recent observations from Arctic Alaska indicate that waters draining through thawing permafrost landscapes are mobilizing iron, carbon, and other heavy metals. These altered processes associated with thaw of permafrost is leading to abrupt changes in the color (orange) of stream and rivers, reflecting a dramatic shift in water quality. Change in water quality includes higher acidity and turbidity, and higher concentrations of sulfate, total iron, and trace metals, such as zinc and nickel. Stream discoloration has also been associated with declines in macroinvertebrate diversity and fish abundance. These findings may have implications for drinking water supplies and subsistence fisheries of rural Alaskan communities.
Deposition on tributary of Salmon River located in Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Deposition on tributary of Salmon River located in Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Tributary of Salmon River located in Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Tributary of Salmon River located in Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Tributary of Salmon River located in the Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Tributary of Salmon River located in the Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Iron seep on the North fork of the Agashashok River, Noatak National Park and Preserve, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Iron seep on the North fork of the Agashashok River, Noatak National Park and Preserve, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Map of orange stream observations across Arctic Inventory and Monitoring Network (ARCN) parks in northern Alaska.
Map of orange stream observations across Arctic Inventory and Monitoring Network (ARCN) parks in northern Alaska.
Tributary of Agashashok River located in the Noatak National Park and Preserve, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Tributary of Agashashok River located in the Noatak National Park and Preserve, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
North fork of the Agashashok River located in Noatak National Park and Preserve, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
North fork of the Agashashok River located in Noatak National Park and Preserve, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.
Impacts of iron mobilization in a stream tributary of the Akillik River located in Kobuk Valley National Park, Alaska. These images were taken two years apart. The clear picture was taken in June 2016 and the orange picture was August 2018.
Impacts of iron mobilization in a stream tributary of the Akillik River located in Kobuk Valley National Park, Alaska. These images were taken two years apart. The clear picture was taken in June 2016 and the orange picture was August 2018.