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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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Interannual colony exchange among breeding Eastern Brown Pelicans Interannual colony exchange among breeding Eastern Brown Pelicans
Colonial seabirds often display high rates of interannual site fidelity to breeding locations, especially as adults. Species using more nearshore or coastal systems, however, may display comparatively less fidelity than highly pelagic species. We used long-term GPS tracking data to assess the frequency of interannual colony switching in Eastern Brown Pelicans (Pelecanus occidentalis...
Authors
Bradley P. Wilkinson, Patrick G.R. Jodice
Pharmaceutical pollution of the world’s rivers Pharmaceutical pollution of the world’s rivers
Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global...
Authors
John L. Wilkinson, Alistair B. A. Boxall, Dana W. Kolpin, Kenneth M. Y. Leung, Racliffe W. S. Lai, Cristobal Galban-Malagon, Aiko D. Adell, J. Mondon, M. Metian, R. Marchant, Alejandra Bouzas-Monroy, Aida Cuni-Sanchez, A. Coors, Carriquiriborde P., M. Rojo, C. Gordon, Magdalena Cara, M. Moermond, Thais Luarte, V. Petrosyan, Yekaterina Perikhanyan, Clare S. Mahon, Christopher J. McGurk, T. Hofmann, T. Kormoker, V. Iniguez, J. Guzman-Otazo, Jean L. Tavares, Francisco Gildasio de Figueiredo, Maria T. P. Razzolini, V. Dougnon, G. Gbaguidi, Oumar Traore, Jules M. Blais, Linda E. Kimpe, M. Wong, D. Wong, R. Ntchantcho, J. Pizarro, Guang-Guo Ying, Chang-Er Chen, Martha Paez, Jina Martinez-Lara, Jean-Paul Otamonga, John Pote, Suspense A. Ifo, Penelope J. Wilson, Silvia Echeverria-Saenz, N. Udikovic-Kolic, M. Milakovic, D. Fatta-Kassinos, L. Ioannou-Ttofa, Vladimira Belusova, J. Vymazal, Maria Cardenas-Bustamante, Bayable A. Kassa, J Garric, A. Chaumot, Peter Gibba, I. Kunchulia, Seidensticker S., G. Lyberatos, Halldór P. Halldórsson, Molly Melling, T. Shashidhar, Manisha Lamba, A. Nastiti, A. Supriatin, N. Pourang, A. Abedini, Omar Abdullah, Salem S. Gharbia, F. Pilla, B. Chefetz, T. Topaz, Koffi Marcellin Yao, B. Aubakirova, R. Beisenova, L. Olaka, Jemimah Mulu, P. Chatanga, V. Ntuli, Nathaniel T. Blama, S. Sherif, Ahmad Zaharin Aris, Ley Juen Looi, M. Niang, Seydou T. Traore, Rik Oldenkamp, O. Ogunbanwo, M. Ashfaq, M. Iqbal, Z. Abdeen, A. O’Dea, Jorge Manuel Morales-Saldana, M. Custodio, H. de la Cruz, I. Navarrete, F. Carvalho, Alhaji B. Gogra, Bashiru M. Koroma, Vesna Cerkvenik-Flajs, Mitja Gombac, M. Thwala, K. Choi, H. Kang, John L. Celestino Ladu, A. Rico, P. Amerashinghe, A. Sobek, G. Horlitz, Armin K. Zenker, Alex C. King, Jheng-Jie Jiang, Rebecca Kariuki, M. Tumbo, U. Tezel, Turgut T. Onay, Julius B. Lejju, Y. Vystavna, Y. Vergeles, H. Heinzen, Andres Perez-Parada, Douglas B. Sims, M. Figy, David Good, C. Teta
The Coles Hill uranium deposit, Virginia, USA: Geology, geochemistry, geochronology, and genetic model The Coles Hill uranium deposit, Virginia, USA: Geology, geochemistry, geochronology, and genetic model
The Coles Hill uranium deposit with an indicated resource of about 130 million lbs. of U3O8 is the largest unmined uranium deposit in the United States. The deposit is hosted in the Taconian (approximately 480 – 450 Ma) Martinsville igneous complex, which consists of the Ordovician Leatherwood Granite (granodiorite) and Silurian Rich Acres Formation (diorite). The host rock was...
Authors
Susan M. Hall, J.S. Beard, Christopher J. Potter, R.J. Bodnar, Leonid A. Neymark, James B. Paces, Craig A. Johnson, G.N. Breit, Robert A. Zielinski, G. J. Aylor
Modeling functional flows in California rivers Modeling functional flows in California rivers
Environmental flows are critical to the recovery and conservation of freshwater ecosystems worldwide. However, estimating desired ranges of environmental flows across large, diverse landscapes is challenging. To advance protections of environmental flows for streams in California, USA, we developed a statewide modeling approach focused on functional components of the natural flow regime
Authors
Theodore E. Grantham, Daren M. Carlisle, Jeanette K. Howard, Belize Lane, Robert Lusardi, Alyssa Obester, Samuel Sandoval-Solis, Bronwen Stanford, Eric D. Stein, Kristine T. Taniguchi-Quan, Sarah M. Yarnell, Julie K. H Zimmerman
Strength and memory of precipitation's control over streamflow across the conterminous United States Strength and memory of precipitation's control over streamflow across the conterminous United States
How precipitation (P) is translated into streamflow (Q) and over what timescales (i.e., “memory”) is difficult to predict without calibration of site-specific models or using geochemical approaches, posing barriers to prediction in ungauged basins or advancement of general theories. Here, we used a data-driven approach to identify regional patterns and exogenous controls on P–Q...
Authors
Edom Moges, Benjamin L. Ruddell, Liang Zhang, Jessica M. Driscoll, Laurel Larsen
Identification of fresh submarine groundwater off the coast of San Diego, USA, using electromagnetic methods Identification of fresh submarine groundwater off the coast of San Diego, USA, using electromagnetic methods
Climate change has a pronounced effect on water resources in many semiarid climates, causing populated areas such as San Diego County (USA), to become more vulnerable to water shortages in the coming decades. To prepare for decreased water supply, San Diego County is adopting policies to decrease water use and to develop additional local sources of water. One new local source of...
Authors
Roslynn B. King, Wesley R. Danskin, Steven Constable, Jillian M. Maloney
Luminescence ages and new interpretations of the timing and deposition of Quaternary sediments at Natural Trap Cave, Wyoming Luminescence ages and new interpretations of the timing and deposition of Quaternary sediments at Natural Trap Cave, Wyoming
Natural Trap Cave, located in the Big Horn Mountains of north-central Wyoming, has a history of trapping and preserving a range of North American fauna that plummeted into the deep vertical entrance. These animal remains were buried and preserved within sediments of the main chamber and, in turn, have helped elucidate the procession of faunal dynamics during the latest glacial cycle. The...
Authors
Shannon A. Mahan, John R. Wood, Dave M Lovelace, Juan Laden, Jenny McGuire, Julie Meachen
Natural and anthropogenic influences on benthic cyanobacteria in streams of the northeastern United States Natural and anthropogenic influences on benthic cyanobacteria in streams of the northeastern United States
Benthic cyanobacteria are widespread in streams and rivers and have the potential to release toxins. In large numbers, these microorganisms and their toxins present a risk to human health. Cyanobacterial abundance in stream biofilms is typically related to single or a limited set of environmental factors, mainly light availability, water temperature, and nutrient concentrations. However...
Authors
Nicholas O. Schulte, Daren M. Carlisle, Sarah A. Spaulding
Limited land base and competing land uses force societal tradeoffs when siting energy development Limited land base and competing land uses force societal tradeoffs when siting energy development
As human populations grow, decisions regarding use of the world's finite land base become increasingly complex. We adopted a land use–conflict scenario involving renewable energy to illustrate one potential cause of these conflicts and resulting tradeoff decisions. Renewable energy industries wishing to expand operations in the United States are limited by multijurisdictional regulations...
Authors
Jill A. Shaffer, Neal D. Niemuth, Charles R. Loesch, Clayton E. Derby, Aaron T. Pearse, Kevin W. Barnes, Terry L. Shaffer, Adam J. Ryba
Comparison of methods for estimating density and population trends for low-density Asian bears Comparison of methods for estimating density and population trends for low-density Asian bears
Populations of bears in Asia are vulnerable to extinction and effective monitoring is critical to measure and direct conservation efforts. Population abundance (local density) or growth (λ) are the most sensitive metrics to change. We discuss the value in implementing spatially explicit capture-recapture (SCR), the current gold standard for density estimation, and open population SCR...
Authors
Dana J. Morin, John Boulanger, Richard Bischof, David C. Lee, Dusit Ngoprasert, Angela K. Fuller, Bruce McLellan, Robert Steinmetz, Sandeep Sharma, Dave Garshelis, Arjun M. Gopalaswamy, Muhammad Ali Nawaz, Ullas Karanth
Drivers of flight performance of California Condors (Gymnogyps californianus) Drivers of flight performance of California Condors (Gymnogyps californianus)
Flight behavior of soaring birds depends on a complex array of physiological, social, demographic, and environmental factors. California Condors (Gymnogyps californianus) rely on thermal and orographic updrafts to subsidize extended bouts of soaring flight, and their soaring flight performance is expected to vary in response to environmental variation and, potentially, with experience...
Authors
Sophie R. Bonner, Sharon A. Poessel, Joseph C. Brandt, Molly T. Astell, James R. Belthoff, Todd E. Katzner
Water chemistry, exposure routes and metal forms determine the bioaccumulation dynamics of silver (ionic and nanoparticulate) in Daphnia magna Water chemistry, exposure routes and metal forms determine the bioaccumulation dynamics of silver (ionic and nanoparticulate) in Daphnia magna
Treatment wetlands utilize various physical and biological processes to reduce levels of organic contaminants, metals, bacteria, and suspended solids. Silver nanoparticles (AgNPs) are one type of contaminant that can enter treatment wetlands and impact the overall treatment efficacy. Grazing by filter-feeding zooplankton, such as Daphnia magna, is critical to treatment wetland...
Authors
Emma Lesser, Fatima Noor Sheikh, Mithun Sikder, Marie Noele Croteau, Natasha Franklin, Mohammed Baalousha, Niveen S. Ismail