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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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Using machine learning to improve predictions and provide insight into fluvial sediment transport Using machine learning to improve predictions and provide insight into fluvial sediment transport

A thorough understanding of fluvial sediment transport is critical to addressing many environmental concerns such as exacerbated flooding, degradation of aquatic habitat, excess nutrients, and the economic challenges of restoring aquatic systems. Fluvial sediment samples are integral for addressing these environmental concerns but cannot be collected at every river and time of interest...
Authors
J. William Lund, Joel T. Groten, Diana L. Karwan, Chad Babcock

Application of tail transmitters for tracking feral horses as an alternative to radio collars Application of tail transmitters for tracking feral horses as an alternative to radio collars

Radio collars have been used to examine the spatial ecology of all North American ungulates, but are rarely used on feral horses due to concerns that they may cause injury. Due to public concerns for animal welfare, an alternative to radio collars for tracking feral horses, particularly stallions, over the short term would be useful. We developed a method of attaching a global...
Authors
Sarah R. B. King, Kathryn A. Schoenecker

Metabolic costs associated with seawater acclimation in a euryhaline teleost, the fourspine stickleback (Apeltes quadracus) Metabolic costs associated with seawater acclimation in a euryhaline teleost, the fourspine stickleback (Apeltes quadracus)

The cost of osmoregulation in teleosts has been debated for decades, with estimates ranging from one to 30 % of routine metabolic rate. The variation in the energy budget appears to be greater for euryhaline fish due to their ability to withstand dynamic salinity levels. In this study, a time course of metabolic and physiological responses of the euryhaline fourspine stickleback (Apeltes...
Authors
Jessica L. Norstog, Stephen D. McCormick, John T. Kelly

The effects of prolonged drought on vegetation dieback and megafires in southern California chaparral The effects of prolonged drought on vegetation dieback and megafires in southern California chaparral

Drought contributed to extensive dieback of southern California chaparral, and normalized difference vegetation index before drought and near the end of the drought was used to estimate this dieback, after accounting for other disturbances recorded in aerial photographs. Within the perimeters of two megafires that occurred after the drought, the 2017 Thomas Fire and the 2018 Woolsey Fire...
Authors
Jon Keeley, Theresa J Brennan-Kane, Alexandra D. Syphard

Simplifying complex fault data for systems-level analysis: Earthquake geology inputs for U.S. NSHM 2023 Simplifying complex fault data for systems-level analysis: Earthquake geology inputs for U.S. NSHM 2023

As part of the U.S. National Seismic Hazard Model (NSHM) update planned for 2023, two databases were prepared to more completely represent Quaternary-active faulting across the western United States: the NSHM23 fault sections database (FSD) and earthquake geology database (EQGeoDB). In prior iterations of NSHM, fault sections were included only if a field-measurement-derived slip rate...
Authors
Alexandra Elise Hatem, Camille Marie Collett, Richard W. Briggs, Ryan D. Gold, Stephen J. Angster, Edward H. Field, Peter M. Powers

Open-source intelligence for conservation biology Open-source intelligence for conservation biology

Open-source intelligence (OSINT) evolved in spy agencies but now is rapidly changing many fields of study, from anthropology to zoology. Despite the fact that OSINT occasionally is used in conservation biology, there is little recognition that some tools and frameworks used by conservation professionals are drawn from this well-established field. The history and conceptual foundations of...
Authors
Todd E. Katzner, Eve C. Thomason, Karrin Huhmann, Tara Conkling, Camille B. Concepcion, Vincent Slabe, Sharon A. Poessel

Using surrogate insects in acid bioassays for development of new controls for Varroa destructor (Arachnida: Varroidae) Using surrogate insects in acid bioassays for development of new controls for Varroa destructor (Arachnida: Varroidae)

Resistance to traditional synthetic compounds by Varroa destructor Anderson and Trueman and shortcomings of the organic acid class of acaracides commonly used in varroa management requires continual development of new controls. V. destructor, however, are difficult to obtain for use in control bioassays because they are obligate parasites that cannot be easily reared outside of a honey...
Authors
Julia Vieira, Casey L. Johnson, Elizabeth M. Varkonyi, Howard Ginsberg, Kassie Picard, Mattew Kiesewetter, Steven R. Alm

Open removal models with temporary emigration and population dynamics to inform invasive animal management Open removal models with temporary emigration and population dynamics to inform invasive animal management

Removal sampling data are the primary source of monitoring information for many populations (e.g., invasive species, fisheries). Population dynamics, temporary emigration, and imperfect detection are common sources of variation in monitoring data and are key parameters for informing management. We developed two open robust-design removal models for simultaneously modeling population...
Authors
Bradley Udell, Julien Martin, Christina Romagosa, J. Hardin Waddle, Fred Johnson, Bryan Falk, Amy A. Yackel Adams, Sarah Funck, Jennifer Ketterlin Eckles, Eric Suarez, Frank Mazzotti

Elevated mercury concentrations and isotope signatures (N, C, Hg) in yellowfin tuna (Thunnus albacares) from the Galápagos Marine Reserve and waters off Ecuador Elevated mercury concentrations and isotope signatures (N, C, Hg) in yellowfin tuna (Thunnus albacares) from the Galápagos Marine Reserve and waters off Ecuador

We examined how dietary factors recorded by C and N influence Hg uptake in 347 individuals of yellowfin tuna (Thunnus albacares), an important subsistence resource from the Galápagos Marine Reserve (GMR) and the Ecuadorian mainland coast (EMC) in 2015-2016. We found no differences in total Hg (THg) measured in red muscle between the two regions and no seasonal differences, likely due to...
Authors
Laia Munoz-Abril, Carlos A Valle, Juan Jose Alava, Sarah E. Janssen, Elsie M. Sunderland, Francisco Rubianes-Landazuri, Steven D Emslie

Genomics-informed delineation of conservation units in a desert amphibian Genomics-informed delineation of conservation units in a desert amphibian

Delineating conservation units (CUs, e.g., evolutionarily significant units, ESUs, and management units, MUs) is critical to the recovery of declining species because CUs inform both listing status and management actions. Genomic data have strengths and limitations in informing CU delineation and related management questions in natural systems. We illustrate the value of using genomic...
Authors
Brenna R. Forester, Melanie Murphy, Chad Mellison, Jeffrey Petersen, David S. Pilliod, Rachel Van Horne, Jim Harvey, W. Chris Funk

Field testing a high-frequency acoustic attenuation system for measuring fine suspended sediments and algal movements Field testing a high-frequency acoustic attenuation system for measuring fine suspended sediments and algal movements

Acoustic measurements of suspended sediment have the potential to allow remote, autonomous monitoring of sediment movements at much higher temporal resolution than traditional manual sampling methods. Although suspended sands present a challenging measurement problem due to their logarithmic distribution with depth, fine clay sediments are distributed evenly throughout a stream cross...
Authors
Wayne O. Carpenter, Bradley T. Goodwiller, Daniel G. Wren, Jason J. Taylor, Jonathan AuBuchon, Jeb E. Brown

Long-term impacts of impervious surface cover change and roadway deicing agent application on chloride concentrations in exurban and suburban watersheds Long-term impacts of impervious surface cover change and roadway deicing agent application on chloride concentrations in exurban and suburban watersheds

Roadway deicing agents, including rock salt and brine containing NaCl, have had a profound impact on the water quality and aquatic health of rivers and streams in urbanized areas with temperate climates. Yet, few studies evaluate impacts to watersheds characterized by relatively low impervious surface cover (ISC; 15 %). Here, we use long-term (1997-2019), monthly streamwater quality data...
Authors
Marissa L. Rossi, Peleg Kremer, Charles A. Cravotta, Krista E. Scheirer, Steven T. Goldsmith
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