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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.
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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Tagger effects in aquatic telemetry: Short-term and delayed impacts of surgery in Atlantic salmon smolts Tagger effects in aquatic telemetry: Short-term and delayed impacts of surgery in Atlantic salmon smolts
Objective An assumption of biotelemetry is that animal performance is unaffected by the tagging process and tag burden, yet this assumption is often untested or not thoroughly explored. Our objective was to explore how transmitter implantation procedures influenced Atlantic Salmon Salmo salar smolt survival and migratory performance.Methods We monitored radio-tagged smolts, first in the...
Authors
Kurt C. Heim, Jonah L. Withers, Theodore Castro-Santos
Maps of active layer thickness in northern Alaska by upscaling P-band polarimetric synthetic aperture radar retrievals Maps of active layer thickness in northern Alaska by upscaling P-band polarimetric synthetic aperture radar retrievals
Extensive, detailed information on the spatial distribution of active layer thickness (ALT) in northern Alaska and how it evolves over time could greatly aid efforts to assess the effects of climate change on the region and also help to quantify greenhouse gas emissions generated due to permafrost thaw. For this reason, we have been developing high-resolution maps of ALT throughout...
Authors
Jane Whitcomb, Richard Chen, Daniel Clewley, John S. Kimball, Neal Pastick, Yonghong Yi, Mahta Moghaddam
Designation of a composite-stratotype section for the lower Paleocene (Danian) Brightseat Formation in Prince George’s County, Maryland, U.S.A. Designation of a composite-stratotype section for the lower Paleocene (Danian) Brightseat Formation in Prince George’s County, Maryland, U.S.A.
The lower Paleocene (Danian) Brightseat Formation consists of fine-grained, dark-gray, micaceous sand and silty clay, with glauconite and abundant, but generally poorly preserved, fossils. The Brightseat Formation represents deposition of lower, but not lowermost, Paleocene sediments that were deposited on the middle to outer shelf of what is now the Atlantic Coastal Plain. A basal...
Authors
Jean Self-Trail, Mercer Parker, David L. Govoni, Laurel M. Bybell, Kristina Frank Gardner, Gregory S. Gohn
The effects of vegetative feedbacks on flood shape, sediment transport, and geomorphic change in a dryland river: Moenkopi Wash, AZ The effects of vegetative feedbacks on flood shape, sediment transport, and geomorphic change in a dryland river: Moenkopi Wash, AZ
Since the 1950s, Moenkopi Wash, in Arizona, United States, has been transformed from a relatively wide river with little riparian vegetation, to a narrow, heavily vegetated river that is less than half of its former width. We analyzed a ∼95-years-long instantaneous-discharge record, an extensive sediment-transport record, oblique and aerial photographs, historical channel surveys, and...
Authors
David J. Dean, David J. Topping
Numbers of wildlife fatalities at renewable energy facilities in a targeted development region Numbers of wildlife fatalities at renewable energy facilities in a targeted development region
Increased interest in renewable energy has fostered development of wind and solar energy facilities globally. However, energy development sometimes has negative environmental impacts, such as wildlife fatalities. Efforts by regional land managers to balance energy potential while minimizing fatality risk currently rely on datasets that are aggregated at continental, but not regional...
Authors
Tara Conkling, Amy L. Fesnock, Todd E. Katzner
Observed impacts of large wind farms on grassland carbon cycling Observed impacts of large wind farms on grassland carbon cycling
No abstract available.
Authors
Donghai Wu, Steven Mark Grodsky, Wenfang Xu, Naijing Liu, Rafael M. Almeida, Liming Zhou, Lee M. Miller, Somnath Baidya Roy, Geng Xia, A. Agrawal, Benjamin Z. Houlton, Alexander S. Flecker, Xiangtao Xu
A new method for bioassessment of ecosystems with complex communities and environmental gradients A new method for bioassessment of ecosystems with complex communities and environmental gradients
Bioassessment of complex and heterogeneous ecosystems is a challenge when there are multiple, strong, natural environmental gradients; unknown, or spatially varying, mixtures of stressors; and large numbers of taxa with unknown responses to both the environmental gradients and the stressors. Current methods of bioassessment are not designed for use under this set of constraints. To...
Authors
Donald Schoolmaster, Valerie A. Partridge
PCB concentrations in riparian spiders (Tetragnathidae) consistently reflect concentrations in water and aquatic macroinvertebrates, but not sediment: Analysis of a seven-year field study PCB concentrations in riparian spiders (Tetragnathidae) consistently reflect concentrations in water and aquatic macroinvertebrates, but not sediment: Analysis of a seven-year field study
Tetragnathid spiders have been used as sentinels to study the biotransport of contaminants between aquatic and terrestrial environments because a significant proportion of their diet consists of adult aquatic insects. A key knowledge gap in assessing tetragnathid spiders as sentinels is understanding the consistency of the year-to-year relationship between contaminant concentrations in...
Authors
Ryan R. Otter, Marc A. Mills, Ken M. Fritz, James M. Lazorchak, Dalon P. White, Gale B. Beaubien, David Walters
Elevated temperature and nutrients lead to increased N2O emissions from salt marsh soils from cold and warm climates Elevated temperature and nutrients lead to increased N2O emissions from salt marsh soils from cold and warm climates
Salt marshes can attenuate nutrient pollution and store large amounts of ‘blue carbon’ in their soils, however, the value of sequestered carbon may be partially offset by nitrous oxide (N2O) emissions. Global climate and land use changes result in higher temperatures and inputs of reactive nitrogen (Nr) into coastal zones. Here, we investigated the combined effects of elevated...
Authors
Sophie A. Comer-Warner, Sami Ullah, Arunabha Dey, Camille Stagg, Tracy Elsey-Quirk, Christopher M. Swarzenski, Fotis Sgouridis, Stefan Krause, Gail L. Chmura
Inundation tolerance, rather than drought tolerance, predicts riparian plant distributions along a local hydrologic gradient Inundation tolerance, rather than drought tolerance, predicts riparian plant distributions along a local hydrologic gradient
Riparian vegetation varies along hydrologic gradients, along which inundation and drought tend to be inversely correlated. Differentiating effects of inundation and drought on plant distributions is critical for predicting impacts of changes to baseflows and designing flow patterns to achieve vegetation objectives in regulated river systems. To this end, we conducted a greenhouse...
Authors
Bradley J. Butterfield, Emily C. Palmquist
Forest age is a primary trait filter for saproxylic beetles in the southeastern United States Forest age is a primary trait filter for saproxylic beetles in the southeastern United States
Many forests throughout the world consist of regenerating mature stands. Although these forests differ in many respects from old-growth (with a history of minimal human disturbance), they typically develop similar structural attributes over time. As a result, older mature forests may be of particular conservation value if they contain resources and microhabitats benefitting saproxylic...
Authors
Clayton Richard Traylor, Michael D. Ulyshen, Joseph V. McHugh, Ryan C. Burner
Unprecedented distribution data for Joshua trees (Yucca brevifolia and Y. jaegeriana) reveal contemporary climate associations of a Mojave Desert icon Unprecedented distribution data for Joshua trees (Yucca brevifolia and Y. jaegeriana) reveal contemporary climate associations of a Mojave Desert icon
Introduction: Forecasting range shifts in response to climate change requires accurate species distribution models (SDMs), particularly at the margins of species' ranges. However, most studies producing SDMs rely on sparse species occurrence datasets from herbarium records and public databases, along with random pseudoabsences. While environmental covariates used to fit SDMS are...
Authors
Todd Esque, Daniel F. Shryock, Gabrielle A. Berr, Felicia Chen, Lesley A. DeFalco, Sabrina Mae Lewicki, Brent Lee Cunningham, Eddie J. Gaylord, Caitlin Shannon Poage, Gretchen Elizabeth Gantz, Ross Adrian Van Gaalen, Benjamin O Gottsacker, Amanda Marie Mcdonald, J.B. Yoder, C.I. Smith, K.E. Nussear