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Publications

USGS research activities relevant to Alaska have yielded more than 9400 historical publications. This page features some of the most recent newsworthy research findings.

Filter Total Items: 3082

Forecasting consequences of changing sea ice availability for Pacific walruses Forecasting consequences of changing sea ice availability for Pacific walruses

The accelerating rate of anthropogenic alteration and disturbance of environments has increased the need for forecasting effects of environmental change on fish and wildlife populations. Models linking projections of environmental change with behavioral responses and bioenergetic effects can provide a basis for these forecasts. There is particular interest in forecasting effects of...
Authors
Mark S. Udevitz, Chadwick V. Jay, Rebecca L. Taylor, Anthony S. Fischbach, William S. Beatty, Shawn R. Noren

Possible behavioural, energetic and demographic effects of displacement of red-throated divers Possible behavioural, energetic and demographic effects of displacement of red-throated divers

This report comprises the main points of discussion and agreement during a workshop, held in Edinburgh in May 2017, to discuss how displacement might affect individuals and the Red-throated diver population; with additional information added by the scientists following the workshop.
Authors
Volker Dierschke, Robert W. Furness, Carrie E. Gray, Ib Krag Petersen, Joel A. Schmutz, Ramunas Zydelis, Francis Daunt

Normalized difference vegetation index as an estimator for abundance and quality of avian herbivore forage in arctic Alaska Normalized difference vegetation index as an estimator for abundance and quality of avian herbivore forage in arctic Alaska

Tools that can monitor biomass and nutritional quality of forage plants are needed to understand how arctic herbivores may respond to the rapidly changing environment at high latitudes. The Normalized Difference Vegetation Index (NDVI) has been widely used to assess changes in abundance and distribution of terrestrial vegetative communities. However, the efficacy of NDVI to measure...
Authors
Kyle R. Hogrefe, Vijay P. Patil, Daniel R. Ruthrauff, Brandt W. Meixell, Michael E. Budde, Jerry W. Hupp, David H. Ward

Genomics of Arctic cod Genomics of Arctic cod

The Arctic cod (Boreogadus saida) is an abundant marine fish that plays a vital role in the marine food web. To better understand the population genetic structure and the role of natural selection acting on the maternally-inherited mitochondrial genome (mitogenome), a molecule often associated with adaptations to temperature, we analyzed genetic data collected from 11 biparentally...
Authors
Robert E. Wilson, George K. Sage, Sarah A. Sonsthagen, Megan C. Gravley, Damian M. Menning, Sandra L. Talbot

Genetic implications of bottleneck effects of differing severities on genetic diversity in naturally recovering populations: An example from Hawaiian coot and Hawaiian gallinule Genetic implications of bottleneck effects of differing severities on genetic diversity in naturally recovering populations: An example from Hawaiian coot and Hawaiian gallinule

The evolutionary trajectory of populations through time is influenced by the interplay of forces (biological, evolutionary, and anthropogenic) acting on the standing genetic variation. We used microsatellite and mitochondrial loci to examine the influence of population declines, of varying severity, on genetic diversity within two Hawaiian endemic waterbirds, the Hawaiian coot and...
Authors
Sarah A. Sonsthagen, Robert E. Wilson, Jared G. Underwood

Monitoring the welfare of polar bear populations in a rapidly changing Arctic Monitoring the welfare of polar bear populations in a rapidly changing Arctic

Most programs for monitoring the welfare of wildlife populations support efforts aimed at reaching discrete management objectives, like mitigating conflict with humans. While such programs can be effective, their limited scope may preclude systemic evaluations needed for large-scale conservation initiatives, like the recovery of at-risk species. We discuss select categories of metrics...
Authors
Todd C. Atwood, Colleen G. Duncan, Kelly A. Patyk, Sarah A. Sonsthagen

Polar bears, Ursus maritimus Polar bears, Ursus maritimus

Polar bears are the largest of the eight species of bears found worldwide and are covered in a pigment-free fur giving them the appearance of being white. They are the most carnivorous of bear species consuming a high-fat diet, primarily of ice-associated seals and other marine mammals. They range throughout the circumpolar Arctic to the southernmost extent of seasonal pack ice.
Authors
Karyn D. Rode, Ian Stirling

Human-polar bear interactions in a changing Arctic: Existing and emerging concerns Human-polar bear interactions in a changing Arctic: Existing and emerging concerns

The behavior and sociality of polar bears (Ursus maritimus) have been shaped by evolved preferences for sea ice habitat and preying on marine mammals. However, human behavior is causing changes to the Arctic marine ecosystem through the influence of greenhouse gas emissions that drive long-term change in ecosystem processes and via the presence of in situ stressors associated with...
Authors
Todd C. Atwood, Kristin S. Simac, Stewart Breck, Geoff York, James Wilder

Implications of rapid environmental change for polar bear behavior and sociality Implications of rapid environmental change for polar bear behavior and sociality

Historically, the Arctic sea ice has functioned as a structural barrier that has limited the nature and extent of interactions between humans and polar bears (Ursus maritimus). However, declining sea ice extent, brought about by global climate change, is increasing the potential for human-polar bear interactions. Loss of sea ice habitat is driving changes to both human and polar bear...
Authors
Todd C. Atwood

A swath across the great divide: Kelp forests across the Samalga Pass biogeographic break A swath across the great divide: Kelp forests across the Samalga Pass biogeographic break

Biogeographic breaks are often described as locations where a large number of species reach their geographic range limits. Samalga Pass, in the eastern Aleutian Archipelago, is a known biogeographic break for the spatial distribution of several species of offshore-pelagic communities, including numerous species of cold-water corals, zooplankton, fish, marine mammals, and seabirds...
Authors
Brenda H. Konar, Matthew S. Edwards, Aaron Bland, Jacob Metzger, Alexandra Ravelo, Sarah Traiger, Ben P. Weitzman

Regionalizing indicators for marine ecosystems: Bering Sea–Aleutian Island seabirds, climate, and competitors Regionalizing indicators for marine ecosystems: Bering Sea–Aleutian Island seabirds, climate, and competitors

Seabirds are thought to be reliable, real-time indicators of forage fish availability and the climatic and biotic factors affecting pelagic food webs in marine ecosystems. In this study, we tested the hypothesis that temporal trends and interannual variability in seabird indicators reflect simultaneously occurring bottom-up (climatic) and competitor (pink salmon) forcing of food webs. To...
Authors
William J. Sydeman, Sarah Ann Thompson, John F. Piatt, Marisol García-Reyes, Stephani Zador, Jeffrey C. Williams, Marc Romano, Heather Renner

Varve formation during the past three centuries in three large proglacial lakes in south-central Alaska Varve formation during the past three centuries in three large proglacial lakes in south-central Alaska

The sediments stored in the large, deep proglacial lakes of south-central Alaska are largely unstudied. We analyzed sediments in 20 cores, up to 160 cm long, from Eklutna, Kenai, and Skilak Lakes, using a combination of repeated lamination counting, radionuclide dating, event stratigraphy, and tephrochronology. We show that the characteristically rhythmic layers were deposited annually...
Authors
Evelin Boes, Maarten Van Daele, Jasper Moernaut, Sabine Schmidt, Britta J.L. Jensen, Nore Praet, Darrell Kaufman, Peter J. Haeussler, Michael G. Loso, Marc De Batist
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