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: 3104
Effects of simple acid leaching of crushed and powdered geological materials on high-precision Pb isotope analyses Effects of simple acid leaching of crushed and powdered geological materials on high-precision Pb isotope analyses
We present new results of simple acid leaching experiments on the Pb isotope composition of USGS standard reference material powders and on ocean island basalt whole rock splits and powders. Rock samples were leached with cold 6 N HCl in an ultrasonic bath, then on a hot plate, and washed with ultrapure H2O before sample digestion in HF‐HNO3 and chromatographic purification of Pb. Lead...
Authors
Erin Todd, Andreas Stracke, Erik Scherer
Serologic evidence of influenza A (H14) virus introduction into North America Serologic evidence of influenza A (H14) virus introduction into North America
Although a diverse population of influenza A viruses (IAVs) is maintained among ducks, geese, shorebirds, and gulls, not all of the 16 avian hemagglutinin (HA) subtypes are equally represented (1). The 14th HA subtype, commonly known as the H14 subtype, was historically limited to isolates from the former Soviet Union in the 1980s (2) and was not subsequently detected until 2010, when...
Authors
Neus Latorre-Margalef, Andrew M. Ramey, Alinde Fojtik, David E. Stallknecht
Breeding ecology of Wandering Tattlers Tringa incana: a study from south-central Alaska Breeding ecology of Wandering Tattlers Tringa incana: a study from south-central Alaska
Montane-nesting shorebirds are arguably the least studied of the Charadriiformes, owing in part to the remoteness of their breeding areas, low nesting densities, and specialized behaviors. We studied a marked population of the Wandering Tattler Tringa incana, during a three-year period (1997–1999) on nesting grounds in south-central Alaska. Two aspects of our results stand out. First is...
Authors
Robert E. Gill, Pavel S. Tomkovich, Maksim N. Dementyev
Strontium isotopes in otoliths of a non-migratory fish (slimy sculpin): Implications for provenance studies Strontium isotopes in otoliths of a non-migratory fish (slimy sculpin): Implications for provenance studies
Heterogeneity in 87Sr/86Sr ratios of river-dissolved strontium (Sr) across geologically diverse environments provides a useful tool for investigating provenance, connectivity and movement patterns of various organisms and materials. Evaluation of site-specific 87Sr/86Sr temporal variability throughout study regions is a prerequisite for provenance research, but the dynamics driving...
Authors
Sean R. Brennan, Diego P. Fernandez, Christian E. Zimmerman, Thure E. Cerling, Randy J. Brown, Matthew J. Wooller
Examining the utility of bulk otolith δ13C to describe diet in wild-caught black rockfish Sebastes melanops Examining the utility of bulk otolith δ13C to describe diet in wild-caught black rockfish Sebastes melanops
Otolith carbon isotope δ13C values may provide temporally resolved diet proxies in fish. If otolith δ13C values reflect diet, isotope values from recent otolith and muscle tissue should correlate and known ontogenetic diet shifts should be reflected in comparisons between otolith material deposited during different life history stages. We analyzed paired otolith and muscle samples for...
Authors
Vanessa R. von Biela, Seth D. Newsome, Christian E. Zimmerman
The conservation of sea otters: a prelude The conservation of sea otters: a prelude
The story of sea otters over the past 275 years chronicles their decline to near extinction and the roads to recovery that cross various conflicts, and in the end provides lessons that will aid the conservation of other threatened species and compromised ecosystems. Sea otters inspire strong human emotions ranging from adoration to disdain. They are protected internationally, federally...
Authors
James L. Bodkin, Shawn E. Larson
Projected changes in diverse ecosystems from climate warming and biophysical drivers in northwest Alaska Projected changes in diverse ecosystems from climate warming and biophysical drivers in northwest Alaska
Climate warming affects arctic and boreal ecosystems by interacting with numerous biophysical factors across heterogeneous landscapes. To assess potential effects of warming on diverse local-scale ecosystems (ecotypes) across northwest Alaska, we compiled data on historical areal changes over the last 25–50 years. Based on historical rates of change relative to time and temperature, we...
Authors
Mark Torre Jorgenson, Bruce G. Marcot, David K. Swanson, Janet C. Jorgenson, Anthony R. DeGange
Predicting effects of environmental change on a migratory herbivore Predicting effects of environmental change on a migratory herbivore
Changes in climate, food abundance and disturbance from humans threaten the ability of species to successfully use stopover sites and migrate between non‐breeding and breeding areas. To devise successful conservation strategies for migratory species we need to be able to predict how such changes will affect both individuals and populations. Such predictions should ideally be process...
Authors
R. A. Stillman, K. A. Wood, Whelan Gilkerson, E. Elkinton, J. M. Black, David H. Ward, M. Petrie
Monitoring digestibility of forages for herbivores: a new application for an old approach Monitoring digestibility of forages for herbivores: a new application for an old approach
Ruminant populations are often limited by how well individuals are able to acquire nutrients for growth, maintenance, and reproduction. Nutrient supply to the animal is dictated by the concentration of nutrients in feeds and the efficiency of digesting those nutrients (i.e., digestibility). Many different methods have been used to measure digestibility of forages for wild herbivores, all...
Authors
Lindsey L. Vansomeren, Perry S. Barboza, Daniel P. Thompson, David D. Gustine
Historic and Contemporary Status of Sea Otters in the North Pacific Historic and Contemporary Status of Sea Otters in the North Pacific
Similar to other species that in recent centuries experienced unregulated human exploitation, sea otters were extirpated throughout large portions of their historic range in the North Pacific. For most of the twentieth century, with cessation of the fur trade and because of concerted efforts at conservation, sea otters recovered much of their historic range and abundance. Late in the...
Authors
James L. Bodkin
Challenges to sea otter recovery and conservation Challenges to sea otter recovery and conservation
Similar to other species that in recent centuries experienced unregulated human exploitation, sea otters were extirpated throughout large portions of their historic range in the North Pacific. For most of the twentieth century, with cessation of the fur trade and because of concerted efforts at conservation, sea otters recovered much of their historic range and abundance. Late in the...
Authors
Brenda E. Ballachey, James L. Bodkin
Ways to be different: Foraging adaptations that facilitate higher intake rates in a northerly wintering shorebird compared with a low-latitude conspecific Ways to be different: Foraging adaptations that facilitate higher intake rates in a northerly wintering shorebird compared with a low-latitude conspecific
At what phenotypic level do closely related subspecies that live in different environments differ with respect to food detection, ingestion and processing? This question motivated an experimental study on rock sandpipers (Calidris ptilocnemis). The species' nonbreeding range spans 20 deg of latitude, the extremes of which are inhabited by two subspecies: C. p. ptilocnemis that winters...
Authors
Daniel R. Ruthrauff, Anne Dekinga, Robert E. Gill, Jan A. van Gils, Theunis Piersma