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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.

Filter Total Items: 74057

Are threatened seabird colonies of the pacific ocean genetically vulnerable? The case of the red-tailed tropicbird, Phaethon rubricauda, as a model species

Oceanic seabirds have suffered population declines and extirpations due to human disturbance and still face multiple threats. Here, we assessed the potential genetic vulnerability of the red-tailed tropicbird, Phaethon rubricauda, a seabird species threatened by human disturbance and listed as ‘least concern’ by the IUCN. Using Single Nucleotide Polymorphisms (SNPs) we evaluated the genetic popula
Authors
Andrea I. Varela, Katherina Brokordt, Juliana A. Vianna, María José Frugone, Stefanie M.H. Ismar-Rebitz, Chris P. Gaskin, Nicholas Carlile, Terence O'Dwyer, Josh Adams, Eric A. Vanderwerf, Guillermo Luna-Jorquera

Paleoproterozoic reworking of Archean crust and extreme back-arc metamorphism in the enigmatic southern Trans-Hudson orogen

The crustal evolution of the southernmost ∼2000–1800 Ma Trans-Hudson orogen (THO) is enigmatic due to burial by Phanerozoic sediments. We provide new insights through petrochronologic analysis of a paragneiss drill core sample. Detrital zircon age peaks at 2625, 2340, and 1880 Ma and Hf isotopes suggest Paleoproterozoic arc development proximal to Archean source(s). Phase equilibria modeling and t
Authors
Ian William Hillenbrand, Amy K. Gilmer, Michael L. Williams, Amanda (Kate) Souders, Michael J. Jercinovic, Heather A. Lowers, Jorge A. Vazquez

Monitoring polar ice change in the twilight zone

Landsat’s new extended data collection program is mapping Arctic and Antarctic regions year-round, even in polar twilight.
Authors
Theodore A. Scambos, Christopher Shuman, Mark Fahnestock, Tasha Snow, Christopher J. Crawford

Exposure to and biomarker responses from legacy and emerging contaminants along three drainages in the Milwaukee Estuary, Wisconsin, USA

Legacy contaminants and contaminants of emerging concern (CECs) were assessed in tree swallow (Tachycineta bicolor) tissue and diet samples from three drainages in the Milwaukee estuary, Wisconsin, USA, to understand exposures and possible biomarker responses. Two remote Wisconsin lakes were assessed for comparative purposes. Bioaccumulative classes of contaminants, such as polybrominated diphenyl
Authors
Christine M. Custer, Thomas W. Custer, Paul Dummer, Sandra L. Schultz, Natalie K. Karouna-Renier, Chi Yen Tseng, Cole W. Matson

Novel approach for ranking DEMs: Copernicus DEM improves one arc second open global topography

We present a practical approach to intercompare a range of candidate digital elevation models (DEMs) based on predefined criteria and a statistically sound ranking approach. The presented approach integrates the randomized complete block design (RCBD) into a novel framework for DEM comparison. The method presented provides a flexible, statistically sound, and customizable tool for evaluating the q
Authors
Conrad Bielski, Carlos López-Vázquez, Carlos H. Grohmann, Peter L. Guth, Laurence Hawker, Dean B. Gesch, Sebastiano Trevisani, Virginia Herrera-Cruz, Serge Riazanoff, Axel Corseaux, Hannes I. Reuter, Peter Strobl

PFAS river export analysis highlights the urgent need for catchment-scale mass loading data

Source apportionment of per- and polyfluoroalkyl substances (PFAS) requires an understanding of the mass loading of these compounds in river basins. However, there is a lack of temporally variable and catchment-scale mass loading data, meaning identification and prioritization of sources of PFAS to rivers for management interventions can be difficult. Here, we analyze PFAS concentrations and loads
Authors
Patrick Byrne, William M. Mayes, Alun L. James, Sean Comber, Emma Biles, Alex Riley, Robert L. Runkel

How quickly do oil and gas wells “Water Out”? Quantifying and contrasting water production trends

Water production from petroleum (oil and natural gas) wells is a topic of increasing environmental and economic importance, yet quantification efforts have been limited to date, and patterns between and within petroleum plays are largely unscrutinized. Additionally, classification of reservoirs as “unconventional” (also known as “continuous”) carries scientific and regulatory importance, but in so
Authors
Seth S. Haines, Brian A. Varela, Marilyn Tennyson, Nicholas J. Gianoutsos

Precipitation uncertainty estimation and rainfall-runoff model calibration using iterative ensemble smoothers

The introduction of iterative ensemble smoothers (IES) for parameter calibration opens avenues for expanding parameter space in surface water hydrologic modeling. Here, we have introduced independent parameters into a model calibration experiment to estimate errors in rainfall forcing data. This approach has the potential to estimate rainfall errors using other hydrological observations and to imp
Authors
Davide Zoccatelli, Daniel B. Wright, Jeremy T. White, Michael N. Fienen, Guo Yu

Assessing trade-offs in developing a landscape-scale nest monitoring programme for a threatened shorebird

Effective monitoring of wildlife species requires thorough planning and development of survey programmes that can address management and conservation objectives. Decisions about monitoring programmes include where to survey, survey design and how much effort to allocate at survey sites are typically predicated on limited budgets and available resources. When the scope of inference requires monitor
Authors
Kristen S. Ellis, Michael J. Anteau, Garrett J. MacDonald, Megan Ring, Mark H. Sherfy, Rose J. Swift, Dustin L. Toy

The chytrid insurance hypothesis: Integrating parasitic chytrids into a biodiversity–ecosystem functioning framework for phytoplankton–zooplankton population dynamics

In temperate lakes, eutrophication and warm temperatures can promote cyanobacteria blooms that reduce water quality and impair food-chain support. Although parasitic chytrids of phytoplankton might compete with zooplankton, they also indirectly support zooplankton populations through the “mycoloop”, which helps move energy and essential dietary molecules from inedible phytoplankton to zooplankton.
Authors
András Abonyi, Johanna Fornberg, Serena Rasconi, Robert Ptacnik, Martin J. Kainz, Kevin D. Lafferty

Microplastic-mediated new mechanism of liver damage: From the perspective of the gut-liver axis

Microplastics (MPs) are environmental contaminants that are present in all environments and can enter the human body, accumulate in various organs, and cause harm through the ingestion of food, inhalation, and dermal contact. The connection between bowel and liver disease and the interplay between gut, liver, and flora has been conceptualized as the “gut-liver axis”. Microplastics can alter the st
Authors
Xiaomei Wang, Kaili Deng, Pei Zhen Zhang, Qiqing Chen, Jason Tyler Magnuson, Wenhui Qiu, Yuping Zhou

Integrating genetic and demographic data to refine indices of abundance for Atlantic sturgeon in the Hudson River, New York

Critical to Atlantic sturgeon Acipenser oxyrinchus oxyrinchus recovery and monitoring is the ability to estimate abundance and identify age- and stock-specific threats to survival. As adult Atlantic sturgeon spend much of their lives broadly distributed in marine and estuarine environments, it is challenging to collect data needed to estimate these demographic parameters in the adult population. A
Authors
Shannon L. White, Richard M. Pendleton, Amanda Higgs, Barbara A. Lubinski, Robin L. Johnson, David C. Kazyak