Descriptions of the full Weekly Findings and links to more information.
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Assessing the Population Consequences of Disturbance and Climate Change for the Pacific Walrus
As the Arctic becomes increasingly ice-free, walruses spend more time at coastal, as opposed to ice-based, haulouts, from which they must expend more energy to reach foraging areas and where they experience an elevated risk of mortality. Sea ice loss is also increasing the anthropogenic footprint in the Arctic, allowing new fisheries, shipping routes, and energy exploration, which creates additional disturbance for walruses. This study developed and applied a modeling framework that incorporated global sea ice model projections and varying degrees of anthropogenic disturbance to assess potential future changes to the Pacific walrus population, a critical subsistence resource for indigenous communities along the Bering and Chukchi Sea coasts in Alaska and Russia. All scenarios indicated a decline in Pacific walrus population vital rates by the end of the 21st century, but our results demonstrated that the intensity of that decline could be mitigated by global efforts to reduce carbon emissions, along with local management and conservation efforts to protect important coastal haulouts and foraging grounds. The publication is available at: https://doi.org/10.3354/meps14635. Learn More>>
Contact: Joe Eisaguirre, Research Wildlife Biologist
Understanding Sea Otter Population Change in Southeast Alaska
Since sea otters were reintroduced to Southeast Alaska in the late 1960s, several efforts over the years have contributed to our present understanding of the population. Many of these efforts used different methods that occasionally led to different estimates of sea otter population abundance in the region. Given recent survey efforts and advances in statistical methods, this fact sheet summarizes how our understanding of the sea otter population in Southeast Alaska has changed through time both as new data were collected, and new methods developed. The fact sheet also highlights some ongoing research and next steps by USGS and collaborators to better understand the population ecology of sea otters and inform management in the region. The fact sheet is available at: https://doi.org/10.3133/fs20243007. Learn More>>
Contact: Joe Eisaguirre, Research Wildlife Biologist
Mechanisms by Which Heatwaves Impact Seabirds
Marine heatwaves are characterized by periods of extreme warming of local to large-scale marine habitat. Effects of marine heatwaves on some seabirds, such as mass die-offs seen with common murres, are well documented. However, but how other seabirds respond to marine heatwaves was poorly understood. Following from a symposium at the 3rd World Seabird Conference in October 2021 on this topic, USGS and other compiled a special section in the journal Marine Ecology Progress Series. This HEAT Theme Section presents recent research to address the knowledge gap of how multiple seabird species and ecosystems respond to extreme ocean temperatures. All articles in the theme section can be accessed here: https://www.int-res.com/abstracts/meps/v737/. Learn More>>
Contact: Mayumi Arimitsu, Research Ecologist
Rusting Rivers in Arctic 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. This paper is available from Nature Communications Earth & Environment at: https://doi.org/10.1038/s43247-024-01446-z. Also view video: Alaska's Rusting Rivers: The Alarming Impact of Permafrost Thaw on Arctic Rivers from the study. Learn More>>
Contact: Michael Carey, Research Fish Biologist
Describing Critical Water Sources for Arctic River Ecosystems
Aufeis is a critical source of water in northern Alaska, and its presence may help us better understand subsurface hydrology in a region with few wells. A new study on what controls the formation of aufeis in northern Alaska can help predict where this ice may occur and the size of aufeis as the Arctic warms. The paper is available at: https://doi.org/10.1002/hyp.15106. Learn More>>
Contact: Josh Koch, Research Hydrologist
Geese Migrating over the northeast Pacific often Fly at the Height of Wind-turbine Blades
The Bureau of Ocean Energy Management is interested in predicting collision risks with possible future offshore windfarms along the Pacific coast of North America. A new study determines how environmental conditions, such as wind and precipitation, affect the selection by birds for certain altitudes above the water. The study found that migrating geese frequently fly at the same height as wind-turbine rotor blades and the results could guide management of wind turbines to minimize collisions with migrating waterfowl. The paper is available at: https://doi.org/10.1111/1365-2664.14612. Learn More>>
Contact: Emily Weisser, Wildlife Biologist
Determining the Importance of Post-den Emergence Behavior of Polar Bears
A new study examined the duration of the post-den emergence period in polar bears and its potential importance in affecting cub survival. The study found that cub survival was higher when females and cubs had a longer period of time near the den after first emerging. This suggests that access to the den site during that period of first emergence may be important for new polar bear cubs. The paper is available at: https://doi.org/10.1093/jmammal/gyae010. Learn More>>
Contact: Karyn Rode, Research Wildlife Biologist
Environmental data can determine changes in a polar bear population when direct data collection is not feasible
The USGS Alaska Science Center, U.S. Fish and Wildlife Service and Alaska Department of Fish and Game recently used environmental and ecological data to estimate indicators of polar bear population health in the Chukchi Sea region of Alaska during 2018-2022, when direct observations of polar bears was not possible because of poor sea ice conditions. Estimates for indicators, such as body condition and recruitment, remained largely stable and within the range of values observed earlier (2008-2017). This study provides a template for using environmental and ecological data to assess potential changes in polar bear populations during times when direct data collection is not feasible. The report is available at https://doi.org/10.1016/j.ecolind.2024.111638. Learn More>>
Contact: Karyn Rode, Research Wildlife Biologist
Descriptions of the full Weekly Findings and links to more information.
Return to Weekly Findings
Assessing the Population Consequences of Disturbance and Climate Change for the Pacific Walrus
As the Arctic becomes increasingly ice-free, walruses spend more time at coastal, as opposed to ice-based, haulouts, from which they must expend more energy to reach foraging areas and where they experience an elevated risk of mortality. Sea ice loss is also increasing the anthropogenic footprint in the Arctic, allowing new fisheries, shipping routes, and energy exploration, which creates additional disturbance for walruses. This study developed and applied a modeling framework that incorporated global sea ice model projections and varying degrees of anthropogenic disturbance to assess potential future changes to the Pacific walrus population, a critical subsistence resource for indigenous communities along the Bering and Chukchi Sea coasts in Alaska and Russia. All scenarios indicated a decline in Pacific walrus population vital rates by the end of the 21st century, but our results demonstrated that the intensity of that decline could be mitigated by global efforts to reduce carbon emissions, along with local management and conservation efforts to protect important coastal haulouts and foraging grounds. The publication is available at: https://doi.org/10.3354/meps14635. Learn More>>
Contact: Joe Eisaguirre, Research Wildlife Biologist
Understanding Sea Otter Population Change in Southeast Alaska
Since sea otters were reintroduced to Southeast Alaska in the late 1960s, several efforts over the years have contributed to our present understanding of the population. Many of these efforts used different methods that occasionally led to different estimates of sea otter population abundance in the region. Given recent survey efforts and advances in statistical methods, this fact sheet summarizes how our understanding of the sea otter population in Southeast Alaska has changed through time both as new data were collected, and new methods developed. The fact sheet also highlights some ongoing research and next steps by USGS and collaborators to better understand the population ecology of sea otters and inform management in the region. The fact sheet is available at: https://doi.org/10.3133/fs20243007. Learn More>>
Contact: Joe Eisaguirre, Research Wildlife Biologist
Mechanisms by Which Heatwaves Impact Seabirds
Marine heatwaves are characterized by periods of extreme warming of local to large-scale marine habitat. Effects of marine heatwaves on some seabirds, such as mass die-offs seen with common murres, are well documented. However, but how other seabirds respond to marine heatwaves was poorly understood. Following from a symposium at the 3rd World Seabird Conference in October 2021 on this topic, USGS and other compiled a special section in the journal Marine Ecology Progress Series. This HEAT Theme Section presents recent research to address the knowledge gap of how multiple seabird species and ecosystems respond to extreme ocean temperatures. All articles in the theme section can be accessed here: https://www.int-res.com/abstracts/meps/v737/. Learn More>>
Contact: Mayumi Arimitsu, Research Ecologist
Rusting Rivers in Arctic 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. This paper is available from Nature Communications Earth & Environment at: https://doi.org/10.1038/s43247-024-01446-z. Also view video: Alaska's Rusting Rivers: The Alarming Impact of Permafrost Thaw on Arctic Rivers from the study. Learn More>>
Contact: Michael Carey, Research Fish Biologist
Describing Critical Water Sources for Arctic River Ecosystems
Aufeis is a critical source of water in northern Alaska, and its presence may help us better understand subsurface hydrology in a region with few wells. A new study on what controls the formation of aufeis in northern Alaska can help predict where this ice may occur and the size of aufeis as the Arctic warms. The paper is available at: https://doi.org/10.1002/hyp.15106. Learn More>>
Contact: Josh Koch, Research Hydrologist
Geese Migrating over the northeast Pacific often Fly at the Height of Wind-turbine Blades
The Bureau of Ocean Energy Management is interested in predicting collision risks with possible future offshore windfarms along the Pacific coast of North America. A new study determines how environmental conditions, such as wind and precipitation, affect the selection by birds for certain altitudes above the water. The study found that migrating geese frequently fly at the same height as wind-turbine rotor blades and the results could guide management of wind turbines to minimize collisions with migrating waterfowl. The paper is available at: https://doi.org/10.1111/1365-2664.14612. Learn More>>
Contact: Emily Weisser, Wildlife Biologist
Determining the Importance of Post-den Emergence Behavior of Polar Bears
A new study examined the duration of the post-den emergence period in polar bears and its potential importance in affecting cub survival. The study found that cub survival was higher when females and cubs had a longer period of time near the den after first emerging. This suggests that access to the den site during that period of first emergence may be important for new polar bear cubs. The paper is available at: https://doi.org/10.1093/jmammal/gyae010. Learn More>>
Contact: Karyn Rode, Research Wildlife Biologist
Environmental data can determine changes in a polar bear population when direct data collection is not feasible
The USGS Alaska Science Center, U.S. Fish and Wildlife Service and Alaska Department of Fish and Game recently used environmental and ecological data to estimate indicators of polar bear population health in the Chukchi Sea region of Alaska during 2018-2022, when direct observations of polar bears was not possible because of poor sea ice conditions. Estimates for indicators, such as body condition and recruitment, remained largely stable and within the range of values observed earlier (2008-2017). This study provides a template for using environmental and ecological data to assess potential changes in polar bear populations during times when direct data collection is not feasible. The report is available at https://doi.org/10.1016/j.ecolind.2024.111638. Learn More>>
Contact: Karyn Rode, Research Wildlife Biologist