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: 2875
Wildlife population dynamics
In this chapter we provide an overview of some core concepts, describe exponential growth as the basic foundation for understanding population dynamics, and discuss some of the factors that can affect wildlife population dynamics. We then show how management insights that can be gained from analyzing the dynamics of individual age or stage classes, examine dynamics of multiple populations across a
Authors
L. Scott Mills, Heather E. Johnson
Survival and reproduction in Arctic caribou are associated with summer forage and insect harassment
Investigators have speculated that the climate-driven “greening of the Arctic” may benefit barren-ground caribou populations, but paradoxically many populations have declined in recent years. This pattern has raised concerns about the influence of summer habitat conditions on caribou demographic rates, and how populations may be impacted in the future. The short Arctic summer provides caribou with
Authors
Heather E. Johnson, Beth Lenart, Dave Gustine, Layne G. Adams, Perry Barboza
Avian influenza antibody prevalence increases with mercury contamination in wild waterfowl
Environmental contamination is widespread and can negatively impact wildlife health. Some contaminants, including heavy metals, have immunosuppressive effects, but prior studies have rarely measured contamination and disease simultaneously, which limits our understanding of how contaminants and pathogens interact to influence wildlife health. Here, we measured mercury concentrations, influenza inf
Authors
Claire Stewart Teitelbaum, Josh T. Ackerman, Mason A. Hill, Jaqueline M. Satter, Michael L. Casazza, Susan E. W. De La Cruz, Walter M. Boyce, Evan James Buck, John M. Eadie, Mark P. Herzog, Elliott Matchett, Cory T. Overton, Sarah H. Peterson, Magdalena Plancarte, Andrew M. Ramey, Jeffery D. Sullivan, Diann Prosser
Modeling the spatial and temporal dynamics of land-based polar bear denning in Alaska
Although polar bears (Ursus maritimus) of the Southern Beaufort Sea (SBS) subpopulation have commonly created maternal dens on sea ice in the past, maternal dens on land have become increasingly prevalent as sea ice declines. This trend creates conditions for increased human–bear interactions associated with local communities and industrial activity. Maternal denning is a vulnerable period in the
Authors
Vijay P. Patil, George M. Durner, David C. Douglas, Todd C. Atwood
In hot water? Patterns of macroinvertebrate abundance in Arctic thaw ponds and relationships with environmental variables
Ongoing environmental change across the Arctic is affecting many freshwater ecosystems, including small thaw ponds that support macroinvertebrates, thus potentially affecting important forage for fish and bird species. To accurately predict how fish and wildlife that depend on these macroinvertebrates will be affected by ecosystem change at high latitudes, understanding proximate factors that infl
Authors
Kirsty E. B. Gurney, Joshua C. Koch, Joel A. Schmutz, J. H. Schmidt, Mark S. Wipfli
U.S. Geological Survey Benchmark Glacier Project
The U.S. Geological Survey Benchmark Glacier Project combines decades of direct glaciological data with remote sensing data to advance the quantitative understanding of glacier-climate interactions. The global loss of glaciers, and consequent implications for water resources, sea level rise, and ecosystem function underscores the importance of U.S. Geological Survey glaciology research to facilit
Authors
Caitlyn Florentine, Lisa L. Mckeon
Divergent gene expression profiles in Alaskan sea otters: An indicator of chronic domoic acid exposure?
An opportunistic investigation into ecosystem instability in Kachemak Bay (KBay), Alaska, has led us to investigate exposure to toxic algae in sea otters. We used gene expression to explore the physiological health of sea otters sampled in KBay in May 2019. We found altered levels of gene transcripts in comparison with reference sea otters from clinically normal, oil-exposed, and nutritionally cha
Authors
Lizabeth Bowen, Susan Knowles, Kathi Lefebvre, Michelle St Martin, Michael Murray, Kimberly A. Kloecker, Daniel Monson, Ben Weitzman, Brenda Ballachey, Heather Coletti, Shannon C. Waters, C Cummings
Temperature variations in the northern Gulf of Alaska across synoptic to century-long time scales
Surface and subsurface moored buoy, ship-based, remotely sensed, and reanalysis datasets are used to investigate thermal variability of northern Gulf of Alaska (NGA) nearshore, coastal, and offshore waters over synoptic to century-long time scales. NGA sea surface temperature (SST) showed a larger positive trend of 0.22 ± 0.10 °C per decade over 1970–2021 compared to 0.10 ± 0.03 °C per decade over
Authors
Seth L. Danielson, Tyler D. Hennon, Daniel Monson, Robert M. Suryan, Rob W. Cambell, Steven J. Baird, Kristine Holderied, Thomas J. Weingartner
Evaluating hydrologic region assignment techniques for ungaged basins in Alaska, USA
Building continental-scale hydrologic models in data-sparse regions requires an understanding of spatial variation in hydrologic processes. Extending these models to ungaged locations requires techniques to group ungaged locations with gaged ones to make process importance and model parameter transfer decisions to ungaged locations. This analysis (1) tested the utility of fundamental streamflow st
Authors
Theodore B. Barnhart, William H. Farmer, John C. Hammond, Graham A. Sexstone, Janet H. Curran, Joshua C. Koch, Jessica M. Driscoll
Reproducibility and variability of earthquake subsidence estimates from saltmarshes of a Cascadia estuary
We examine fossil foraminiferal assemblages from 20 sediment cores to assess sudden relative sea-level (RSL) changes across three mud-over-peat contacts at three salt marshes in northern Humboldt Bay, California (~44.8°N, -124.2°W). We use a validated foraminiferal-based Bayesian transfer function to evaluate the variability of subsidence stratigraphy at a range of 30-6000 m across an estuary. We
Authors
Jason Scott Padgett, Simon E. Engelhart, Harvey M. Kelsey, Robert C. Witter, Niamh Cahill
Sclerochronological records of environmental variability and bivalve growth in the Pacific Arctic
The Pacific Arctic region has experienced, and is projected to continue experiencing, rapid climate change. Large uncertainties exist in our understanding of the impact these physical changes have on the region’s ecology. This is, in part, due to the lack of long-term data. Here we investigate bivalve mollusc growth increment width chronologies (sclerochronologies) to develop a long-term biologica
Authors
David J. Reynolds, Vanessa R. von Biela, Kenneth H. Dunton, David C. Douglas, Bryan A. Black
Proceedings of the Highly Pathogenic Avian Influenza and Wild Birds Webinar Series, August 2–5, 2021
In light of ongoing and geographically widespread highly pathogenic avian influenza (HPAI) outbreaks in wild birds throughout much of Eurasia during 2020–21, the Interagency Steering Committee for Avian Influenza Surveillance in Wild Migratory Birds disseminated an informational memorandum in January 2021 to highlight the need for enhanced surveillance and heightened awareness in North America. Th
Authors
M. Camille Hopkins, J. Russ Mason, Giavanna Haddock, Andrew M. Ramey