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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
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Central Andean (28–34°S) flood record 0–25 ka from Salinas del Bebedero, Argentina Central Andean (28–34°S) flood record 0–25 ka from Salinas del Bebedero, Argentina
The Salinas del Bebedero occupies an isolated basin in the foreland of central Argentina at 33°S and was flooded repeatedly over past 25 ka. Isotopic evidence demonstrates that this flooding was due to overflow of the nearby Río Desaguadero with waters derived from the distant (≥300 km) central Andes between 28–34°S. Stratigraphic and shoreline evidence shows that floods occurred most...
Authors
Jay Quade, Elad Dente, Allison Cartwright, Adam M. Hudson, Sebastian Jimenez, David McGee
Integrated hydrologic model development and postprocessing for GSFLOW using pyGSFLOW Integrated hydrologic model development and postprocessing for GSFLOW using pyGSFLOW
pyGSFLOW is a python package designed to create new GSFLOW integrated hydrologic models, read existing models, edit model input data, run GSFLOW models, process output, and visualize model data.
Authors
Joshua Larsen, Ayman H. Alzraiee, Richard G. Niswonger
Population viability analysis for a pond-breeding amphibian under future drought scenarios in the southeastern United States Population viability analysis for a pond-breeding amphibian under future drought scenarios in the southeastern United States
Climate change effects are contributing to widespread declines of amphibians, and pond-breeding species may be particularly sensitive to future drought conditions that restrict wetland hydroperiods and decrease opportunities for successful breeding and recruitment. Pond-breeding amphibian populations can compensate for periodic droughts via episodic booms in recruitment, but studies...
Authors
Brian A. Crawford, John C. Maerz, Vanessa C. K. Terrell, Clinton T. Moore
Pre-breeding foraging ecology of three tern species nesting in the Gulf of Maine Pre-breeding foraging ecology of three tern species nesting in the Gulf of Maine
A variety of seabird species migrate annually from wintering grounds in the Southern Hemisphere to the Gulf of Maine, USA to breed and raise their young. Post-migration, adult seabirds depend on the spatio-temporal match of reliable food resources to replenish energy reserves before breeding. However, the conditions during this critical window of time are becoming increasingly uncertain...
Authors
Rachel M. Bratton, Henry Legett, Paula Shannon, Keenan Yakola, Alexander R. Gerson, Michelle Staudinger
Range-wide persistence of the endangered arroyo toad (Anaxyrus californicus) for 20+ years following a prolonged drought Range-wide persistence of the endangered arroyo toad (Anaxyrus californicus) for 20+ years following a prolonged drought
Prolonged drought due to climate change has negatively impacted amphibians in southern California, U.S.A. Due to the severity and length of the current drought, agencies and researchers had growing concern for the persistence of the arroyo toad (Anaxyrus californicus), an endangered endemic amphibian in this region. Range-wide surveys for this species had not been conducted for at least...
Authors
Cynthia Joan Hitchcock, Elizabeth Gallegos, Adam R. Backlin, Russell Barabe, Peter H. Bloom, Kimberly Boss, Cheryl S. Brehme, Christopher W. Brown, Denise Clark, Elizabeth R. Clark, Kevin Cooper, Julie Donnell, Edward L Ervin, Peter Famolaro, Kim M. Guilliam, Jaquelyn Hancock, Nicholas Hess, Steven Howard, Valerie Hubbartt, Patrick Lieske, Robert E. Lovich, Tritia Matsuda, Katherin Meyer-Wilkins, Kamarul Muri, Barry Nerhus, Jeffrey A. Nordland, Brock Ortega, Robert Packard, Ruben Ramirez, Sam C. Stewart, Samuel Sweet, Manna L. Warburton, Jeffrey Wells, Ryan Winkleman, Kirsten Winter, Brian Zitt, Robert N. Fisher
Sensitivity of headwater streamflow to thawing permafrost and vegetation change in a warming Arctic Sensitivity of headwater streamflow to thawing permafrost and vegetation change in a warming Arctic
Climate change has the potential to impact headwater streams in the Arctic by thawing permafrost and subsequently altering hydrologic regimes and vegetation distribution, physiognomy and productivity. Permafrost thaw and increased subsurface flow have been inferred from the chemistry of large rivers, but there is limited empirical evidence of the impacts to headwater streams. Here we...
Authors
Joshua C. Koch, Ylva Sjoberg, Jonathan A. O’Donnell, Michael P. Carey, Pamela L. Sullivan, A. Terskaia
Methanogenic archaea in subsurface coal seams are biogeographically distinct: An analysis of metagenomically-derived mcrA sequences Methanogenic archaea in subsurface coal seams are biogeographically distinct: An analysis of metagenomically-derived mcrA sequences
The production of methane as an end-product of organic matter degradation in the absence of other terminal electron acceptors is common, and has often been studied in environments such as animal guts, soils, and wetlands due to its potency as a greenhouse gas. To date however, the study of the biogeographic distribution of methanogens across coal seam environments has been minimal. Here...
Authors
Bronwyn C Campbell, Paul Greenfield, Gong, Elliott P. Barnhart, David J. Midgley, Ian T. Paulsen, Simon C. George
Extreme rainstorms drive exceptional organic carbon export from forested humid-tropical rivers in Puerto Rico Extreme rainstorms drive exceptional organic carbon export from forested humid-tropical rivers in Puerto Rico
Extreme rainfall events in the humid-tropical Luquillo Mountains, Puerto Rico export the bulk of suspended sediment and particulate organic carbon. Using 25 years of river carbon and suspended sediment data, which targeted hurricanes and other large rainstorms, we estimated biogenic particulate organic carbon yields of 65 ± 16 tC km−2 yr−1 for the Icacos and 17.7 ± 5.1 tC km−2 yr−1 for...
Authors
Kasey E. Clark, Robert Stallard, Sheila F. Murphy, Martha A. Scholl, Grizelle Gonzalez, Alain F. Plante, William H. McDowell
Noninvasive sampling of mountain lion hair using modified foothold traps Noninvasive sampling of mountain lion hair using modified foothold traps
Genetic analysis of non-invasively obtained samples is an increasingly affordable option for many wildlife studies, but it has remained difficult to obtain high-quality samples from many species. We modified 8” Belisle foot snares (Belisle Enterprises, Quebec, Canada) to non-invasively obtain mountain lion (Puma concolor) hair samples in unbaited trail sets. We deployed 22 hair traps...
Authors
Tricia S. Rossettie, Travis W. Perry, James W. Cain
Harmful algal blooms in the Alaskan Arctic: An emerging threat as oceans warm Harmful algal blooms in the Alaskan Arctic: An emerging threat as oceans warm
Harmful algal blooms (HABs) present an emerging threat to human and ecosystem health in the Alaskan Arctic. Two HAB toxins are of concern in the region: saxitoxins (STXs), a family of compounds produced by the dinoflagellate Alexandrium catenella, and domoic acid (DA), produced by multiple species in the diatom genus Pseudo-nitzschia. These potent neurotoxins cause paralytic and amnesic...
Authors
Donald Anderson, Evangeline Fachon, Katherine Hubbard, Kathi Lefebvre, Peigen Lin, Robert Pickart, Mindy Richlen, Gay Sheffield, Caroline R. Van Hemert
Detection of Splendidofilaria sp. (Onchocercidae:Splendidofilariinae) Microfilaria within Alaskan ground-dwelling birds in the grouse subfamily tetraoninae using taqman probe-based real-time PCR Detection of Splendidofilaria sp. (Onchocercidae:Splendidofilariinae) Microfilaria within Alaskan ground-dwelling birds in the grouse subfamily tetraoninae using taqman probe-based real-time PCR
Grouse and ptarmigan (Galliformes) harbor fairly diverse helminth faunas that can impact the host's health, including filarial nematodes in the genus Splendidofilaria. As host and parasite distributions are predicted to shift in response to recent climate change, novel parasites may be introduced into a region and impose additional stressors on bird populations. Limited information is...
Authors
Stephen E. Greiman, Robert E. Wilson, Briana Sesmundo, Jack Reakoff, Sarah A. Sonsthagen
Great diversity of KSα sequences from bat-associated microbiota suggests novel sources of uncharacterized natural products Great diversity of KSα sequences from bat-associated microbiota suggests novel sources of uncharacterized natural products
Polyketide synthases (PKSs) are multidomain enzymes in microorganisms that synthesize complex, bioactive molecules. PKS II systems are iterative, containing only a single representative of each domain: ketosynthase alpha (KSα�), ketosynthase beta and the acyl carrier protein. Any gene encoding for one of these domains is representative of an entire PKS II biosynthetic gene cluster (BGC)...
Authors
Paris S. Hamm, Jennifer J.M. Hathaway, Ara S. Winter, Nicole A. Caimi, Debbie C. Buecher, Ernest W. Valdez, Diana E. Northup