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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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Effects of tidally varying river flow on entrainment of juvenile salmon into Sutter and Steamboat Sloughs Effects of tidally varying river flow on entrainment of juvenile salmon into Sutter and Steamboat Sloughs
Survival of juvenile salmonids in the Sacramento–San Joaquin Delta (Delta) varies by migration route, and thus the proportion of fish that use each route affects overall survival through the Delta. Understanding factors that drive routing at channel junctions along the Sacramento River is therefore critical to devising management strategies that maximize survival. Here, we examine...
Authors
Jason G. Romine, Russell Perry, Paul Stumpner, Aaron R. Blake, Jon R. Burau
Hippopotamus movements structure the spatiotemporal dynamics of an active anthrax outbreak Hippopotamus movements structure the spatiotemporal dynamics of an active anthrax outbreak
Globally, anthrax outbreaks pose a serious threat to people, livestock, and wildlife. Furthermore, environmental change can exacerbate these outbreak dynamics by altering the host–pathogen relationship. However, little is known about how the quantitative spatial dynamics of host movement and environmental change may affect the spread of Bacillus anthracis, the causative agent of anthrax...
Authors
Keenan Stears, Melissa H. Schmitt, Wendy Christine Turner, Douglas J. McCauley, Epaphras A. Muse, Halima Kiwango, Daniel Matheyo, Benezeth M. Mutayoba
Seasonal controls on sediment delivery and hydrodynamics in a vegetated tidally influenced interdistributary island Seasonal controls on sediment delivery and hydrodynamics in a vegetated tidally influenced interdistributary island
River deltas are maintained by a continuous supply of terrestrial sediments that provide critical land building material to help sustain and protect vulnerable ecological communities and serve as natural storm protection barriers. Local hydrodynamics are important in determining the degree to which fluvial sediments are removed from the water column and retained on the delta complex...
Authors
Richard Styles, Gregg Snedden, S. Jarrell Smith, Duncan B. Bryant, Brandon M. Boyd, Joseph Z. Gailani, Brady Couvillion, Edward Race
Teleseismic waves reveal anisotropic poroelastic response of wastewater disposal reservoir Teleseismic waves reveal anisotropic poroelastic response of wastewater disposal reservoir
Connecting earthquake nucleation in basement rock to fluid injection in basal, sedimentary reservoirs, depends heavily on choices related to the poroelastic properties of the fluid-rock system, thermo-chemical effects notwithstanding. Direct constraints on these parameters outside of laboratory settings are rare, and it is commonly assumed that the rock layers are isotropic. With the...
Authors
Andrew J. Barbour, Nicholas M. Beeler
Spatial Gaussian processes improve multi-species occupancy models when range boundaries are uncertain and nonoverlapping Spatial Gaussian processes improve multi-species occupancy models when range boundaries are uncertain and nonoverlapping
Species distribution models enable practitioners to analyze large datasets of encounter records and make predictions about species occurrence at unsurveyed locations. In omnibus surveys that record data on multiple species simultaneously, species ranges are often nonoverlapping and misaligned with the administrative unit defining the spatial domain of interest (e.g., a state or province)
Authors
Wilson Wright, Kathryn M. Irvine, Tom Rodhouse, Andrea R. Litt
Use of the MODFLOW 6 water mover package to represent natural and managed hydrologic connections Use of the MODFLOW 6 water mover package to represent natural and managed hydrologic connections
The latest release of MODFLOW 6, the current core version of the MODFLOW groundwater modeling software, debuted a new package dubbed the “mover” (MVR). Using a generalized approach, MVR facilitates the transfer of water among any arbitrary combination of simulated features (i.e., pumping wells, stream, drains, lakes, etc.) within a MODFLOW 6 simulation. Four “rules” controlling the...
Authors
Eric D. Morway, Christian D. Langevin, Joseph D. Hughes
Advancing estuarine ecological forecasts: Seasonal hypoxia in Chesapeake Bay Advancing estuarine ecological forecasts: Seasonal hypoxia in Chesapeake Bay
Ecological forecasts are quantitative tools that can guide ecosystem management. The coemergence of extensive environmental monitoring and quantitative frameworks allows for widespread development and continued improvement of ecological forecasting systems. We use a relatively simple estuarine hypoxia model to demonstrate advances in addressing some of the most critical challenges and
Authors
Donald Scavia, Isabella Bertani, Jeremy M. Testa, Aaron J. Bever, Joel D. Blomquist, Marjorie A. M. Friedrichs, Lewis C. Linker, Bruce Michael, Rebecca Murphy, Gary W. Shenk
Identifying metabolic alterations associated with coral growth anomalies using 1H NMR metabolomics Identifying metabolic alterations associated with coral growth anomalies using 1H NMR metabolomics
Coral growth anomalies (GAs) are tumor-like protrusions that are detrimental to coral health, affecting both the coral skeleton and soft tissues. These lesions are increasingly found throughout the tropics and are commonly associated with high human population density, yet little is known about the molecular pathology of the disease. Here, we investigate the metabolic impacts of GAs...
Authors
Erik R. Andersson, Rusty D. Day, Thierry M. Work, Paul E. Anderson, Cheryl M. Woodley, Tracey B. Schock
Low MSP-1 haplotype diversity in the West Palearctic population of the avian malaria parasite Plasmodium relictum Low MSP-1 haplotype diversity in the West Palearctic population of the avian malaria parasite Plasmodium relictum
Background Although avian Plasmodium species are widespread and common across the globe, limited data exist on how genetically variable their populations are. Here, the hypothesis that the avian blood parasite Plasmodium relictum exhibits very low genetic diversity in its Western Palearctic transmission area (from Morocco to Sweden in the north and Transcaucasia in the east) was tested...
Authors
Olof Hellgren, Victor Kelbskopf, Vincenzo A Ellis, Arif Ciloglu, Melanie Duc, Xi Huang, Ricardo J. Lopes, Vanessa A Mata, Sargis A. Aghayan, Abdullah Inci, Sergei V. Drovetski
Response of fish assemblages to restoration of rapids habitat in a Great Lakes connecting channel Response of fish assemblages to restoration of rapids habitat in a Great Lakes connecting channel
Rapids habitats are critical spawning and nursery grounds for multiple Laurentian Great Lakes fishes of ecological importance such as lake sturgeon, walleye, and salmonids. However, river modifications have destroyed important rapids habitat in connecting channels by modifying flow profiles and removing large quantities of cobble and gravel that are preferred spawning substrates of...
Authors
A. Molina-Moctezuma, N. Godby, K. Kapuscinski, Edward F. Roseman, K. Skubik, A. Moerke
Integrating thermal infrared stream temperature imagery and spatial stream network models to understand natural spatial thermal variability in streams Integrating thermal infrared stream temperature imagery and spatial stream network models to understand natural spatial thermal variability in streams
Under a warmer future climate, thermal refuges could facilitate the persistence of species relying on cold-water habitat. Often these refuges are small and easily missed or smoothed out by averaging in models. Thermal infrared (TIR) imagery can provide empirical water surface temperatures that capture these features at a high spatial resolution (
Authors
Matthew R. Fuller, Joseph L. Ebersole, Naomi Detenbeck, Rochelle Labisoa, P.T. Leinenbach, Christian E. Torgersen
Recency of faulting and subsurface architecture of the San Diego Bay pull-apart basin, California, USA Recency of faulting and subsurface architecture of the San Diego Bay pull-apart basin, California, USA
In southern California, plate boundary motion between the North American and Pacific plates is distributed across several sub-parallel fault systems. The offshore faults of the California Continental Borderland (CCB) are thought to accommodate ~10-15% of the total plate boundary motion, but the exact distribution of slip and the mechanics of slip partitioning remain uncertain. The...
Authors
Drake Moore Singleton, Jillian M. Maloney, Daniel S. Brothers, Shannon Klotsko, Neal W. Driscoll, Thomas K. Rockwell