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Browse more than 65,000 articles authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.

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Mechanisms by which marine heatwaves impact seabirds

Marine heatwaves (MHWs) are characterized by periods of extreme warming of local to basin-scale marine habitat. Effects of MHWs on some seabirds (e.g. mass die-offs) are well documented, but mechanisms by which seabirds respond to MHWs remain poorly understood. Following from a symposium at the 3rd World Seabird Conference, this Theme Section presents recent research to address this knowledge gap.
Authors
John F. Piatt, Mayumi L. Arimitsu, Sarah Ann Thompson, Rob Suryan, Rory Wilson, Kyle Elliott, W.J. Sydeman

Origins and nature of large explosive eruptions in the lower East Rift Zone of Kīlauea volcano, Hawaii: Insights from ash characterization and geochemistry

Several powerful explosive eruptions have taken place in the populated lower East Rift Zone of Kīlauea within the past ∼750 years. These have created distinctive landforms, including a tephra rim enclosing Puʻulena Crater immediately south of the Puna Geothermal Venture power station, a tuff cone at Kapoho Crater near the eastern cape of the Island of Hawaiʻi, and a set of littoral cones, the Sand
Authors
Richard W. Hazlett, Johanne Schmith, Allan Lerner, Drew T. Downs, Erin P. Fitch, Carolyn E. Parcheta, Cheryl A. Gansecki, Sarah Spaulding

Climate-influenced phenology of larval fish transport in a large lake

Elucidating physical transport phenologies in large lakes can aid understanding of larval recruitment dynamics. Here, we integrate a series of climate, hydrodynamic, biogeochemical, and Lagrangian particle dispersion models to: (1) simulate hatch and transport of fish larvae throughout an illustrative large lake, (2) evaluate patterns of historic and potential future climate-induced larval transpo
Authors
Spencer T. Gardner, Mark D. Rowe, Pengfei Xue, Xing Zhou, Peter Alsip, David Bunnell, Paris D. Collingsworth, Edward S. Rutherford, Tomas O. Hook

Microtopographic variation as a potential early indicator of ecosystem state change and vulnerability in salt marshes

As global climate change alters the magnitude and rates of environmental stressors, predicting the extent of ecosystem degradation driven by these rapidly changing conditions becomes increasingly urgent. At the landscape scale, disturbances and stressors can increase spatial variability and heterogeneity — indicators that can serve as potential early warnings of declining ecosystem resilience. Inc
Authors
Alexander J. Smith, Glenn R. Guntenspergen, Joel A. Carr, David C Walters, Matthew Kirwan

Applying local and global sensitivity analysis to inform bigheaded carp management

Natural resource managers commonly use population-level models to aid in understanding the status of target populations or the potential implications of management actions. Sensitivity analyses, specifically, local sensitivity analysis (LSA) and global sensitivity analysis (GSA), exist as tools to improve understanding of these models, the importance of specific parameters to model outcomes, and t
Authors
Richard A. Erickson, Benjamin J. Marcek, Hannah Mann Thompson, Brian Schoenung, John M. Dettmers, Michael N. Fienen

Identifying the forage base and critical forage taxa for Chesapeake waterbirds

To effectively maximize the conservation value of management plans intended to capture ecosystem-wide health, it is essential to obtain an understanding of emergent patterns in dietary dynamics spanning many species. Chesapeake Bay, USA, is a critical ecosystem used annually by a diverse assortment of waterbird species, including several of conservation concern. However, the ecosystem is threatene
Authors
Matthew Hack, Jeffery D. Sullivan, Cody M. Kent, Diann Prosser

A genomic hotspot of diversifying selection and structural change in the hoary bat (Lasiurus cinereus)

BackgroundPrevious work found that numerous genes positively selected within the hoary bat (Lasiurus cinereus) lineage are physically clustered in regions of conserved synteny. Here I further validate and expand on those finding utilizing an updated L. cinereus genome assembly and additional bat species as well as other tetrapod outgroups.MethodsA chromosome-level assembly was generated by chromat
Authors
Robert S. Cornman

Formation and evolution of the Pacific-North American (San Andreas) plate boundary: Constraints from the crustal architecture of northern California

The northward migration of the Mendocino triple junction (MTJ) drives a fundamental plate boundary transformation from convergence to translation; producing a series of strike-slip faults, that become the San Andreas plate boundary. We find that the 3-D structure of the Pacific plate lithosphere in the vicinity of the MTJ controls the location of San Andreas plate boundary formation. At the time o
Authors
Kevin P. Furlong, Antonio Villasenor, Harley M. Benz, Kirsty A. McKenzie

Carbon isotope trends across a century of herbarium specimens suggest CO2 fertilization of C4 grasses.

Increasing atmospheric CO2 is changing the dynamics of tropical savanna vegetation. C3 trees and grasses are known to experience CO2 fertilization, whereas responses to CO2 by C4 grasses are more ambiguous.Here, we sample stable carbon isotope trends in herbarium collections of South African C4 and C3 grasses to reconstruct 13C discrimination.We found that C3 grasses showed no trends in 13C discri
Authors
Isa del Toro, Madelon Florence Case, Allison Karp, Jasper Slingsby, A. Carla Staver

Two risk assessments: Evaluating the use of indicator HF183 Bacteroides versus pathogen measurements for modelling recreational illness risks in an urban watershed

The purpose of this study was to evaluate the performance of HF183 Bacteroides for estimating pathogen exposures during recreational water activities. We compared the use of Bacteroides-based exposure assessment to exposure assessment that relied on pathogen measurements. We considered two types of recreational water sites: those impacted by combined sewer overflows (CSOs) and those not impacted b
Authors
K Skiendzielewski, Tucker R. Burch, Joel P. Stokdyk, Shannon McGinnis, S McLoughlin, Aaron Firnstahl, Sandy Spencer, Mark A. Borchardt, Heather Murphy

Temporally dense monitoring of pathogen occurrence at four drinking-water well sites – Insights and Implications

Yearlong, event based, microbiological and chemical sampling was conducted at four public water supply well sites spanning a range of geologic settings and well depths to look for correlation between precipitation events and microbial occurrence. Near-continuous monitoring using autosamplers occurred just before, during, and after 5–7 sampling events triggered by rainfall and/or snowmelt. Microbia
Authors
James F. Walsh, Randall J. Hunt, Anita C. Anderson, David W. Owens, Nancy Rice

A phylogeographical study of the discontinuously distributed Harlequin Duck (Histrionicus histrionicus)

Species distributions are often indicative of historical biogeographical events and contemporary spatial biodiversity patterns. The Harlequin Duck Histrionicus histrionicus is a sea duck of conservation concern that has a disjunct distribution, with discrete portions of its range associated with northern Pacific and Atlantic Ocean basins. Movement data indicate migratory connectivity within region
Authors
Kim T Scribner, Sandra Talbot, Barbara J. Pierson, John D Robinson, Richard B. Lanctot, Daniel Esler, Kathryn Dickson