Diffusion modeling reveals effects of multiple release sites and human activity on a recolonizing apex predator
Joseph M. Eisaguirre, Perry J. Willliams, Xinyi Lu, Michelle L. Kissling, William S. Beatty, George G. Esslinger, Jamie N. Womble, Mevin Hooten
2021, Movement Ecology (9)
BackgroundReintroducing predators is a promising conservation tool to help remedy human-caused ecosystem changes. However, the growth and spread of a reintroduced population is a spatiotemporal process that is driven by a suite of factors, such as habitat change, human activity, and prey availability. Sea otters (Enhydra lutris) are...
Monochromatic long-period seismicity prior to the 2012 earthquake swarm at Little Sitkin Volcano, Alaska
Matthew M. Haney, Helena Buurman, Stephen Holtkamp, Stephen McNutt
2021, Frontiers in Earth Science (9)
Detection of the earliest stages of unrest is one of the most challenging and yet critically needed aspects of volcano monitoring. We investigate a sequence of five unusual long-period (LP) earthquakes that occurred in the days prior to the onset of a months-long volcano-tectonic (VT) earthquake swarm beneath Little Sitkin...
GIS-based identification of areas that have resource potential for lode gold in Alaska
Susan M. Karl, Douglas C. Kreiner, George N. D. Case, Keith A. Labay, Nora B. Shew, Matthew Granitto, Bronwen Wang, Eric D. Anderson
2021, Open-File Report 2021-1041
Several comprehensive, data-driven geographic information system (GIS) analyses were conducted to assess prospectivity for lode gold in Alaska. These analyses use available geospatial datasets of lithologic, geochemical, mineral occurrence, and geophysical data to build models for recognizing different types of gold deposits within physiographic units defined by stream drainage basins...
Fully accounting for nest age reduces bias when quantifying nest survival
Emily L. Weiser
2021, Ornithological Applications (123)
Accurately measuring nest survival is challenging because nests must be discovered to be monitored, but nests are typically not found on the first day of the nesting interval. Studies of nest survival therefore often monitor a sample that overrepresents older nests. To account for this sampling bias, a daily...
Chemical analysis of archived stream-sediment samples, Alaska
Bronwen Wang, George N. D. Case, Mathew Granitto, Keith A. Labay, Nora B. Shew, Andrew D. Ingraham, Jaime S. Azain, Zachary C. Bueghly, Susan M. Karl, Karen D. Kelley
2021, Open-File Report 2021-1058
Geochemical data are presented for more than 1,500 archived stream-sediment samples and accompanying quality control samples. The archived sediments were reanalyzed to improve the stream geochemical dataset for Alaska and to support ongoing U.S. Geological Survey (USGS) studies. Sediment samples were primarily from the USGS Mineral Resources Program’s sample...
Comparison of historical water temperature measurements with landsat analysis ready data provisional surface temperature estimates for the Yukon River in Alaska
Carson Baughman, Jeff Conaway
2021, Remote Sensing (13)
Water temperature is a key element of freshwater ecological systems and a critical element within natural resource monitoring programs. In the absence of in situ measurements, remote sensing platforms can indirectly measure water temperature over time and space. The Earth Resources Observation and Science (EROS) Center has processed archived Landsat...
Egg retention of high-latitude sockeye salmon (Oncorhynchus nerka) in the Pilgrim River, Alaska, during the Pacific marine heatwave of 2014–2016
Michael P. Carey, Vanessa R. von Biela, Ashley Dunker, Kevin D. Keith, Merlyn Schelske, Charlie Lean, Christian E. Zimmerman
2021, Polar Biology (44) 1643-1654
Ocean and freshwater conditions can influence spawning success of Pacific salmon (Oncorhynchus spp.) by governing the energy content of fish at the start of and during the spawning migration. Ocean conditions determine the energy stores of fish at the freshwater entry, while freshwater conditions determine how quickly stored energy is depleted...
Physiomorphic transformation in extreme endurance migrants: Revisiting the case of bar-tailed godwits preparing for trans-pacific flights
Theunis Piersma, Robert E. Gill Jr., Daniel R. Ruthrauff
2021, Frontiers in Ecology and Evolution (9)
In a 1998 paper entitled “Guts don’t fly: small digestive organs in obese bar-tailed godwits,” Piersma and Gill (1998) showed that the digestive organs were tiny and the fat loads huge in individuals suspected of embarking on a non-stop flight from Alaska to New Zealand. It was suggested that prior...
Extensibility of U-net neural network model for hydrographic feature extraction and implications for hydrologic modeling
Larry V. Stanislawski, Ethan J. Shavers, Shaowen Wang, Zhe Jiang, E. Lynn Usery, Evan Moak, Alexander Duffy, Joel Schott
2021, Remote Sensing (13)
Accurate maps of regional surface water features are integral for advancing ecologic, atmospheric and land development studies. The only comprehensive surface water feature map of Alaska is the National Hydrography Dataset (NHD). NHD features are often digitized representations of historic topographic map blue lines and may be outdated. Here we...
Translocations maintain genetic diversity and increase connectivity in sea otters, Enhydra lutris
Shawn E. Larson, Roderick B. Gagne, James L. Bodkin, Michael J. Murray, Katherine Ralls, Lizabeth Bowen, Raphael Leblois, Sylvain Piry, Maria Cecilia Penedo, M. Tim Tinker, Holly B. Ernest
2021, Marine Mammal Science (37) 1475-1497
Sea otters, Enhydra lutris, were once abundant along the nearshore areas of the North Pacific. The international maritime fur trade that ended in 1911 left 13 small remnant populations with low genetic diversity. Subsequent translocations into previously occupied habitat resulted in several reintroduced populations along the coast...
Sea otter population collapse in southwest Alaska: Assessing ecological covariates, consequences, and causal factors
M. Tim Tinker, James L. Bodkin, Lizabeth Bowen, Brenda Ballachey, Gena Bentall, Alexander Burdin, Heather Coletti, George G. Esslinger, Brian B. Hatfield, Michael C. Kenner, Kimberly A. Kloecker, Brenda Konar, A. Keith Miles, Daniel Monson, Michael J. Murray, Ben Weitzman, James A. Estes
2021, Ecological Monographs (91)
Sea otter (Enhydra lutris) populations in southwest Alaska declined substantially between about 1990 and the most recent set of surveys in 2015. Here we report changes in the distribution and abundance of sea otters, and covarying patterns in reproduction, mortality, body size and condition, diet and...
Diet composition and body condition of polar bears (Ursus maritimus) in relation to sea ice habitat in the Canadian High Arctic
Katie R. N. Florko, Gregory W. Thiemann, Jeffrey F. Bromaghin, Evan S. Richardson
2021, Polar Biology (44) 1445-1456
Polar bears (Ursus maritimus) rely on sea ice for hunting marine mammal prey. Declining sea ice conditions associated with climate warming have negatively affected polar bears, especially in the southern portion of their range. At higher latitudes, the transition from multi-year ice to thinner annual ice...
The biophysical role of water and ice within permafrost nearing collapse: Insights from novel geophysical observations
Stephanie R. James, Burke J. Minsley, Jack McFarland, Eugenie S. Euskirchen, Colin W. Edgar, Mark Waldrop
2021, JGR Earth Surface (126)
The impact of permafrost thaw on hydrologic, thermal, and biotic processes remains uncertain, in part due to limitations in subsurface measurement capabilities. To better understand subsurface processes in thermokarst environments, we collocated geophysical and biogeochemical instruments along a thaw gradient between forested permafrost and collapse-scar bogs at the Alaska Peatland...
Evaluation of remote mapping techniques for earthquake-triggered landslide inventories in an urban subarctic environment: A case study of the 2018 Anchorage, Alaska Earthquake
Sabrina N. Martinez, Lauren N. Schaefer, Kate E. Allstadt, Eric M. Thompson
2021, Frontiers Earth Science Journal (9)
Earthquake-induced landslide inventories can be generated using field observations but doing so can be challenging if the affected landscape is large or inaccessible after an earthquake. Remote sensing data can be used to help overcome these limitations. The effectiveness of remotely sensed data to produce landslide inventories, however,...
Integrated hydrology and operations modeling to evaluate climate change impacts in an agricultural valley irrigated with snowmelt runoff
Wesley Kitlasten, Eric D. Morway, Richard G. Niswonger, Murphy Gardner, Jeremy T. White, Enrique Triana, David J. Selkowitz
2021, Water Resources Research (57)
Applying models to developed agricultural regions remains a difficult problem because there are no existing modeling codes that represent both the complex physics of the hydrology and anthropogenic manipulations to water distribution and consumption. We apply an integrated groundwater – surface water and hydrologic river operations model...
Diverse patterns of migratory timing, site use, and site fidelity by Alaska-breeding Whimbrels
Daniel R. Ruthrauff, Christopher M. Harwood, T. Lee Tibbitts, Nils Warnock, Robert E. Gill Jr.
2021, Journal of Field Ornithology (92) 156-172
Birds that conduct long-distance migrations exhibit varied patterns of consistency in migratory timing and site use. Understanding variation in these traits among populations can help uncover mechanisms driving migratory behaviors and identify potential population threats. Whimbrels (Numenius phaeopus)...
Alaska landbird montoring survey: Alaska regional protocol framework for monitoring landbirds using point counts
Colleen M. Handel, Steven M. Matsuoka, Melissa N. Cady, Diane A. Granfors
2021, Report
Alaska provides habitat for 143 species of landbirds that occur regularly in the state, about half of which breed predominantly north of the border between the contiguous United States and Canada. The road-based North American Breeding Bird Survey (BBS) provides some data on population trends in Alaska, but most northern...
Surface flow velocities from space: Particle image velocimetry of satellite video of a large, sediment-laden river
Carl J. Legleiter, Paul J. Kinzel
2021, Frontiers in Water (3)
Conventional, field-based streamflow monitoring in remote, inaccessible locations such as Alaska poses logistical challenges. Safety concerns, financial considerations, and a desire to expand water-observing networks make remote sensing an appealing alternative means of collecting hydrologic data. In an ongoing effort to develop non-contact methods for measuring river discharge, we evaluated...
Willow drives changes in arthropod communities of northwestern Alaska: Ecological implications of shrub expansion
Molly Mcdermott, Patricia Doak, Colleen M. Handel, Greg A. Breed, Christa Mulder
2021, Ecosphere (12)
Arthropods serve as complex linkages between plants and higher-level predators in Arctic ecosystems and provide key ecosystem services such as pollination and nutrient cycling. Arctic plant communities are changing as tall woody shrubs expand onto tundra, but potential effects on arthropod abundance and food web structure...
GIS-based identification of areas that have resource potential for sediment-hosted Pb-Zn deposits in Alaska
Karen D. Kelley, Garth E. Graham, Keith A. Labay, Nora B. Shew
2021, Open-File Report 2020-1147
A state-wide Geographic Information System analysis was conducted to assess prospectivity for lead (Pb) and zinc (Zn) in sediment-hosted deposits in Alaska. The datasets that were utilized include publicly available geospatial datasets of lithologic, geochemical, and mineral occurrence data. Key characteristics of Pb-Zn deposits were identified in available datasets and...
The 2008-2010 subsidence of Dallol volcano on the 2 spreading Erta Ale ridge: InSAR observations and source models
Maurizio Battaglia, Carolina Paglia, Stefano Meuti
2021, Remote Sensing (13)
In this work, we study the subsidence of Dallol, an explosive crater and hydrothermal area along the spreading Erta Ale ridge of Afar (Ethiopia). No volcanic products exist at the surface. However, a diking episode in 2004, accompanied by dike-induced faulting, indicates that Dallol is an active...
Dissolved Fe supply to the central Gulf of Alaska is inferred to be derived from Alaskan glacial dust that is not resolved by dust transport models
John Crusius
2021, JGR-Biogeosciences (126)
Re-examination of previously published dissolved iron time-series data from Ocean Station Papa in the central Gulf of Alaska (GoA) reveals 33-70% increases in the dissolved iron inventories occurring between September and February of successive years, implying a source of Fe to this region during autumn or early winter. Because I...
Spring phenology drives range shifts in a migratory Arctic ungulate with key implications for the future
John P. Severson, Heather E. Johnson, Stephen M. Arthur, William Leacock, Michael J. Suitor
2021, Global Change Biology (27) 4546-4563
Annual variation in phenology can have profound effects on the behavior of animals. As climate change advances spring phenology in ecosystems around the globe, it is becoming increasingly important to understand how animals respond to variation in the timing of seasonal events and how their responses...
Dynamic landscapes in northwestern North America structured populations of wolverines (Gulo gulo)
Dianna M Krejsa, Sandra L. Talbot, George K. Sage, Sarah A. Sonsthagen, Thomas S Jung, Audrey J Magoun, Joseph A. Cook
2021, Journal of Mammology (102) 891-908
Cyclic climatic and glacial fluctuations of the Late Quaternary produced a dynamic biogeographic history for high latitudes. To refine our understanding of this history in northwestern North America, we explored geographic structure in a wide-ranging carnivore, the wolverine (Gulo gulo). We examined genetic variation in populations across mainland Alaska, coastal...
Using next generation sequencing of alpine plants to improve fecal metabarcoding diet analysis for Dall’s sheep
Kelly E. Williams, Damian M. Menning, Eric J. Wald, Sandra L. Talbot, Kumi L. Rattenbury, Laura R. Prugh
2021, BMC Research Notes (14)
ObjectivesDall’s sheep (Ovis dalli dalli) are important herbivores in the mountainous ecosystems of northwestern North America, and recent declines in some populations have sparked concern. Our aim was to improve capabilities for fecal metabarcoding diet analysis of Dall’s sheep and other herbivores by contributing new sequence data for...
