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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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Evaluating the context dependency of large river nursery habitats for fishes in the lower Red River catchment Evaluating the context dependency of large river nursery habitats for fishes in the lower Red River catchment

Both fine- and coarse-scale physicochemical conditions affect the quantity and quality of nursery habitats within riverine ecosystems. Nursery habitats in large, braided, and sandbed streams such as the lower Red River of Oklahoma, Texas, and Arkansas are not well described and likely vary among species. Identification of nursery habitats is important for developing proper conservation...
Authors
Paul Q. Ramsey, John Dattilo, Dennis DeVries, Shannon K. Brewer

A comprehensive assessment of submarine landslides and mass wasting processes offshore southern California A comprehensive assessment of submarine landslides and mass wasting processes offshore southern California

It is critical to characterize submarine landslide hazards near dense coastal populations, especially in areas with active faults, which can trigger slope failure, subsequent tsunamis, and damage seabed infrastructure during earthquake shaking. Offshore southern California, numerous marine geophysical surveys have been conducted over the past decade, and high-resolution bathymetric and...
Authors
M. Walton, James E. Conrad, Antoinette Gabrielle Papesh, Daniel S. Brothers, Jared W. Kluesner, Mary McGann, Peter Dartnell

Molecular sexing of birds using quantitative PCR (qPCR) of sex-linked genes and logistic regression models Molecular sexing of birds using quantitative PCR (qPCR) of sex-linked genes and logistic regression models

The ability to sex individuals is an important component of many behavioural and ecological investigations and provides information for demographic models used in conservation and species management. However, many birds are difficult to sex using morphological characters or traditional molecular sexing methods. In this study, we developed probabilistic models for sexing birds using...
Authors
Eleni Leto Petrou, Laura Celeste Scott, Cherie Marie Mckeeman, Andrew M. Ramey

Matching decision support modeling frameworks to disease emergence stages and associated management objectives Matching decision support modeling frameworks to disease emergence stages and associated management objectives

Wildlife disease management decisions often require rapid responses to situations that are fraught with uncertainty. By recognizing that management is implemented to achieve specific objectives, resource managers and science partners can identify an analysis technique and develop a monitoring plan to evaluate management effectiveness. For emerging infectious diseases, objectives may take...
Authors
Evan H. Campbell Grant, Brittany A. Mosher, Riley Bernard, Alexander Wright, Robin Russell

Unravelling spatial heterogeneity of inundation pattern domains for 2D analysis of fluvial landscapes and drainage networks Unravelling spatial heterogeneity of inundation pattern domains for 2D analysis of fluvial landscapes and drainage networks

Fluvial landscape analysis is an essential part of geomorphology, hydrology, ecology, and cartography. It is traditionally focused on the transition between hillslopes and channel domain, in which the network drainage is represented by static flow lines. However, the natural fluctuations of the processes occurring in the watershed induce lateral and longitudinal expansions and...
Authors
Pierfranco Costabile, Carmelina Costanzo, Margherita Lombardo, Ethan J. Shavers, Larry Stanislawski

Seasonal and decadal subsurface thaw dynamics of an Aufeis feature investigated through numerical simulations Seasonal and decadal subsurface thaw dynamics of an Aufeis feature investigated through numerical simulations

Aufeis (also known as icings) are large sheet-like masses of layered ice that form in river channels in arctic environments in the winter as groundwater discharges to the land surface and subsequently freezes. Aufeis are important sources of water for Arctic river ecosystems, bolstering late summer river discharge and providing habitat for caribou escaping insect harassment. The aim of...
Authors
Alexi Lainis, Roseanna M. Neupauer, Joshua C. Koch, Michael Gooseff

Insight into sources of benzene, TCE, and PFOA/PFAS in groundwater at Naval Air Station Whiting Field, Florida, through numerical particle-tracking simulations Insight into sources of benzene, TCE, and PFOA/PFAS in groundwater at Naval Air Station Whiting Field, Florida, through numerical particle-tracking simulations

Past waste-disposal activities at Naval Air Station Whiting Field (NASWF) have led to elevated concentrations of contaminants in the underlying sand and gravel aquifer. Contaminants include two of the most commonly detected chemicals in groundwater in many countries (benzene and trichloroethylene (TCE)) and the “forever chemicals” per- and poly-fluoroalkyl substances (PFAS) such as
Authors
Eric Swain, James E. Landmeyer, Michael A. Singletary, Shannon E. Provenzano

The post-emergence period for denning polar bears: Phenology and influence on cub survival The post-emergence period for denning polar bears: Phenology and influence on cub survival

Among polar bears (Ursus maritimus), only parturient females den for extended periods, emerging from maternal dens in spring after having substantially depleted their energy reserves during a fast that can exceed 8 months. Although den emergence coincides with a period of increasing prey availability, polar bears typically do not depart immediately to hunt, but instead remain at the den...
Authors
Erik Andersen, Ryan R. Wilson, Karyn D. Rode, George M. Durner, Todd C. Atwood, David Gustine

Characterization of change in tree cover state and condition over the conterminous United States Characterization of change in tree cover state and condition over the conterminous United States

Variability in the effects of disturbances and extreme climate events can lead to changes in tree cover over time, including partial or complete loss, with diverse ecological consequences. It is therefore critical to identify in space and time the change processes that lead to tree cover change. Studies of change are often hampered by the lack of data capable of consistently detecting...
Authors
Francis K Dwomoh, Roger F. Auch

Nonbreeding waterfowl behavioral response to crewed and uncrewed aerial surveys on conservation areas in Missouri Nonbreeding waterfowl behavioral response to crewed and uncrewed aerial surveys on conservation areas in Missouri

Monitoring waterfowl populations provides the basis for improving habitat quantity and quality, establishing harvest regulations, and ensuring sustainable waterfowl populations through appropriate management. Waterfowl biologists currently use a variety of population and habitat monitoring methods ranging from informal ground observations to low-level occupied aircraft surveys. Although...
Authors
Reid A. Viegut, Elisabeth B. Webb, Andrew H. Raedeke, Zhicheng Tang, Yang Zhang, Yi Shang

Comparison of two otolith processing methods for silver carp age estimation Comparison of two otolith processing methods for silver carp age estimation

Accurate age estimates are critical in the development, implementation, and assessment of silver carp (Hypophthalmichthys molitrix) management plans. Lapilli otoliths are the most commonly used calcified structures for silver carp age estimation, but studies on the precision of two established preparation methods [i.e., grind-and-burn (GB), thin-section (TS)] are lacking. Therefore, we...
Authors
Jeff N. Stevens, Cooper E. Barshinger, Jonathan J. Spurgeon, Michael A. Eggleton, Steve E. Lochmann
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