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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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The distribution of anadromy in steelhead / rainbow trout in the Eel River, northwestern California The distribution of anadromy in steelhead / rainbow trout in the Eel River, northwestern California

To inform management and conservation of the species, we investigated the distribution of anadromy and residency of steelhead/rainbow trout (Oncorhynchus mykiss) in the Eel River of northwestern California. We determined maternal anadromy versus residency for 106 juvenile O. mykiss using otolith microchemistry. To attempt to relate patterns of anadromy with environmental factors known to...
Authors
Bret C. Harvey, Rodney J. Nakamoto, Adam J.R. Kent, Christian E. Zimmerman

Conspecific and congeneric interactions shape increasing rates of breeding dispersal of northern spotted owls Conspecific and congeneric interactions shape increasing rates of breeding dispersal of northern spotted owls

Breeding dispersal, the movement from one breeding territory to another, is rare for philopatric species that evolved within relatively stable environments, such as the old-growth coniferous forests of the Pacific Northwest. Although dispersal is not inherently maladaptive, the consequences of increased dispersal on population dynamics in populations whose historical dispersal rates are...
Authors
Julianna M. A. Jenkins, Damon B. Lesmeister, Eric D. Forsman, Katie M. Dugger, Steven H. Ackers, Steven Andrews, Scott A. Gremel, Bruce A. Hollen, Chris E. McCafferty, Shane Pruett, Janice A. Reid, Stan A. Sovern, David Wiens

Fragmentation and streamflow metrics drive prairie chub (Macrhybopsis australis) occurrence in the upper Red River basin Fragmentation and streamflow metrics drive prairie chub (Macrhybopsis australis) occurrence in the upper Red River basin

Dam construction threatens global aquatic biodiversity by fragmenting stream networks and altering flow regimes. The negative effects of dams are exacerbated by increased drought periods and associated water withdrawals, especially in semi-arid regions. Stream fishes are particularly threatened owing to their mobile nature and requirement for multiple habitats to complete their life...
Authors
R. Mollenhauer, Shannon K. Brewer, J.S. Perkin, D. Swedberg, M. Wedgeworth, Z.D. Steffensmeier

Global tropical reef fish richness could decline by around half if corals are lost Global tropical reef fish richness could decline by around half if corals are lost

Reef fishes are a treasured part of marine biodiversity, and also provide needed protein for many millions of people. Although most reef fishes might survive projected increases in ocean temperatures, corals are less tolerant. A few fish species strictly depend on corals for food and shelter, suggesting that coral extinctions could lead to some secondary fish extinctions. However...
Authors
Giovanni Strona, Kevin D. Lafferty, Simone Fattorini, Pieter Beck, Francois Guilhaumon, Roberto Arrigoni, Simone Montano, Davide Seveso, Paolo Galli, Serge Planes, Valeriano Parravicini

Quantifying the representation of plant communities in the protected areas of the U.S.: An analysis based on the U.S. National Vegetation Classification Groups Quantifying the representation of plant communities in the protected areas of the U.S.: An analysis based on the U.S. National Vegetation Classification Groups

Plant communities represent the integration of ecological and biological processes and they serve as an important component for the protection of biological diversity. To measure progress towards protection of ecosystems in the United States for various stated conservation targets we need datasets at the appropriate thematic, spatial, and temporal resolution. The recent release of the...
Authors
Alexa McKerrow, Anne Davidson, Matthew J. Rubino, Don Faber-Langendoen, Daryn Dockter

The drying regimes of non-perennial rivers and streams The drying regimes of non-perennial rivers and streams

The flow regime paradigm is central to the aquatic sciences, where flow drives critical functions in lotic systems. Non-perennial streams comprise the majority of global river length, thus we extended this paradigm to stream drying. Using 894 USGS gages, we isolated 25,207 drying events from 1979 to 2018, represented by a streamflow peak followed by no flow. We calculated hydrologic...
Authors
Adam N. Price, C. Nathan Jones, John C. Hammond, Margaret Zimmer, Samuel Zipper

Identifying elusive piercing points along the North American transform margin using mixture modeling of detrital zircon data from sedimentary units and their crystalline sources Identifying elusive piercing points along the North American transform margin using mixture modeling of detrital zircon data from sedimentary units and their crystalline sources

The San Gabriel and Canton faults represent early stages in the development of the San Andreas fault system. However, questions of timing of initiation and magnitude of slip on these structures remain unresolved, with published estimates ranging from 42-75 km and likely starting in the Miocene. This uncertainty in slip history reflects an absence of appropriate piercing points. We...
Authors
Clark Gilbert, Zane R. Jobe, Samuel Johnstone, Glenn R. Sharman

Divergent climate change effects on widespread dryland plant communities driven by climatic and ecohydrological gradients Divergent climate change effects on widespread dryland plant communities driven by climatic and ecohydrological gradients

Plant community response to climate change will be influenced by individual plant responses that emerge from competition for limiting resources that fluctuate through time and vary across space. Projecting these responses requires an approach that integrates environmental conditions and species interactions that result from future climatic variability. Dryland plant communities are being
Authors
Kyle A. Palmquist, Daniel Rodolphe Schlaepfer, Rachel R. Renne, Steve Torbit, Kevin Doherty, Thomas E. Remington, Greg Watson, John B. Bradford, William K. Lauenroth

Evaluation of regulatory action and surveillance as preventive risk-mitigation to an emerging global amphibian pathogen Batrachochytrium salamandrivorans (Bsal) Evaluation of regulatory action and surveillance as preventive risk-mitigation to an emerging global amphibian pathogen Batrachochytrium salamandrivorans (Bsal)

The emerging amphibian pathogen Batrachochytrium salamandrivorans (Bsal) is a severe threat to global urodelan (salamanders, newts, and related taxa) biodiversity. Bsal has not been detected, to date, in North America, but the risk is high because North America is one of the global hotspots for urodelan biodiversity. The North American and United States response to the discovery of Bsal...
Authors
Daniel A. Grear, Brittany A. Mosher, Katherine Richgels, Evan H. Campbell Grant

Machine learning to identify geologic factors associated with production in geothermal fields: A case-study using 3D geologic data, Brady geothermal field, Nevada Machine learning to identify geologic factors associated with production in geothermal fields: A case-study using 3D geologic data, Brady geothermal field, Nevada

In this paper, we present an analysis using unsupervised machine learning (ML) to identify the key geologic factors that contribute to the geothermal production in Brady geothermal field. Brady is a hydrothermal system in northwestern Nevada that supports both electricity production and direct use of hydrothermal fluids. Transmissive fluid-flow pathways are relatively rare in the...
Authors
Drew L. Siler, Jeffrey D. Pepin, Velimir V. Vesselinov, Maruti K. Mudunuru, Bulbul Ahmmed

Monochromatic long-period seismicity prior to the 2012 earthquake swarm at Little Sitkin Volcano, Alaska Monochromatic long-period seismicity prior to the 2012 earthquake swarm at Little Sitkin Volcano, Alaska

Detection of the earliest stages of unrest is one of the most challenging and yet critically needed aspects of volcano monitoring. We investigate a sequence of five unusual long-period (LP) earthquakes that occurred in the days prior to the onset of a months-long volcano-tectonic (VT) earthquake swarm beneath Little Sitkin volcano in the Aleutian Islands during late 2012. The long-period...
Authors
Matthew M. Haney, Helena Buurman, Stephen Holtkamp, Stephen McNutt
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