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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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High-frequency variability of carbon dioxide fluxes in tidal water over a temperate salt marsh High-frequency variability of carbon dioxide fluxes in tidal water over a temperate salt marsh
Existing analyses of salt marsh carbon budgets rarely quantify carbon loss as CO2 through the air–water interface in inundated marshes. This study estimates the variability of partial pressure of CO2 (pCO2) and air–water CO2 fluxes over summer and fall of 2014 and 2015 using high-frequency measurements of tidal water pCO2 in a salt marsh of the U.S. northeast region. Monthly mean CO2...
Authors
Shuzhen Song, Zhaohui Aleck Wang, Kevin D. Kroeger, Meagan J. Eagle, Sophie N. Chu, Jianzhong Ge
Mapping methane reduction potential of tidal wetland restoration in the United States Mapping methane reduction potential of tidal wetland restoration in the United States
Coastal wetlands can emit excess methane in cases where they are impounded and artificially freshened by structures that impede tidal exchange. We provide a new assessment of coastal methane reduction opportunities for the contiguous United States by combining multiple publicly available map layers, reassessing greenhouse gas emissions datasets, and applying scenarios informed by...
Authors
James Holmquist, Meagan J. Eagle, Rebecca Molinari, Sydney K. Nick, Liana Stachowicz, Kevin D. Kroeger
Long-term trends in Arctic riverine chemistry signal multi-faceted northern change Long-term trends in Arctic riverine chemistry signal multi-faceted northern change
Rivers integrate processes occurring throughout their watersheds and are therefore sentinels of change across broad spatial scales. River chemistry also regulates ecosystem function across Earth’s land–ocean continuum, exerting control from the micro- (for example, local food web) to the macro- (for example, global carbon cycle) scale. In the rapidly warming Arctic, a wide range of...
Authors
Suzanne E. Tank, James W. McClelland, Robert G. M. Spencer, Alexander I. Shiklomanov, Anya Suslova, Florentina Moatar, Rainer Amon, Lee W. Cooper, Greg Elias, Vyacheslav Gordeev, Christopher Guay, Tatiana Gurtovaya, Lyudmila Kosmenko, Edda A. Mutter, Bruce Peterson, Bernhard Peucker-Ehrenbrink, Peter Raymond, Paul Schuster, Lindsay Scott, Robin Staples, Robert G. Striegl, Mikhail Tretiakov, Alexander V. Zhulidov, Nikita Zimov, Sergey Zimov, Robert M. Holmes
Predation of invasive silver carp by native largemouth bass is size-selective in the Illinois River Predation of invasive silver carp by native largemouth bass is size-selective in the Illinois River
Silver carp (Hypophthalmichthys molitrix) are a nonnative, planktivorous, and highly invasive species of cyprinid located throughout the Mississippi River Basin. Although they co-occur with largemouth bass (Micropterus nigricans), an abundant native predatory fish, their predator–prey relationship is poorly understood. This potential relationship warrants investigation as largemouth bass...
Authors
Eli G. Lampo, Jonathan M. Vallazza, Cory A. Anderson, Levi E. Solomon, Richard M. Pendleton, Toby J. Holda, James T. Lamer
Identifying demographic and environmental drivers of population dynamics and viability in an endangered top predator using an integrated model Identifying demographic and environmental drivers of population dynamics and viability in an endangered top predator using an integrated model
Knowledge about the demographic and environmental factors underlying population dynamics is fundamental to designing effective conservation measures to recover depleted wildlife populations. However, sparse monitoring data or persistent knowledge gaps about threats make it difficult to identify the drivers of population dynamics. In situations where small, declining, or depleted...
Authors
Amanda J. Warlick, Gina K Himes Boor, Tamara L McGuire, Kim E. W. Shelden, Eiren K. Jacobson, Charlotte Boyd, Paul Wade, Andre E. Punt, Sarah J. Converse
Scale-dependent tradeoffs between habitat and time in explaining Alligator Gar (Atractosteus spatula) movement Scale-dependent tradeoffs between habitat and time in explaining Alligator Gar (Atractosteus spatula) movement
Ecological theory predicts that movement by riverine fishes at the population level is characterized by both stationary and mobile individuals together creating a leptokurtic distribution of movement distances. However, studies testing this theory typically ignore spatial heterogeneity in riverscapes, and the theory has not been tested using Alligator Gar (Atractosteus spatula), a...
Authors
Johnathan K. Ellard, Hayden C. Roberts, Daniel J. Daugherty, Paul B. Fleming, Matthew Ross Acre, Joshuah S. Perkin
Independent age estimates resolve the controversy of ancient human footprints at White Sands Independent age estimates resolve the controversy of ancient human footprints at White Sands
Human footprints at White Sands National Park, New Mexico, USA, reportedly date to between ~23,000 and 21,000 years ago according to radiocarbon dating of seeds from the aquatic plant Ruppia cirrhosa. These ages remain controversial because of potential old carbon reservoir effects that could compromise their accuracy. We present new calibrated 14C ages of terrestrial pollen collected...
Authors
Jeffrey S. Pigati, Kathleen B. Springer, Jeffrey S. Honke, David Wahl, Marie Rhondelle Champagne, Susan R.H. Zimmerman, Harrison J. Gray, Vincent L. Santucci, Daniel Odess, David Bustos, Matthew R. Bennett
Wide-area debris field and seabed characterization of a deep ocean dump site surveyed by autonomous underwater vehicles Wide-area debris field and seabed characterization of a deep ocean dump site surveyed by autonomous underwater vehicles
Disposal of industrial and hazardous waste in the deep ocean was a pervasive global practice near coastlines in the 20th century. Uncertainty in the quantity, location, and contents of dumped materials at historical disposal sites underscores ongoing risks to marine ecosystems and human health. This study presents analysis of a 150-km2 wide-area sidescan sonar survey conducted in March...
Authors
Sophia T. Merrifield, Sean Celona, Ryan A. McCarthy, Andrew Pietruszka, Heidi Batchelor, Robert Hess, Andrew Nager, Raymond Young, Kurt Sadorf, Lisa A. Levin, David L. Valentine, James E. Conrad, Eric J. Terrill
HABs and HAB nots: Dynamics of phytoplankton blooms across similar oligotrophic reservoirs HABs and HAB nots: Dynamics of phytoplankton blooms across similar oligotrophic reservoirs
Increasing frequency and intensity of cyanobacterial Harmful Algal Blooms (HABs) threaten human and aquatic ecosystem health. Improving our understanding of HABs across a range of systems will be critical to understanding and potentially minimizing risk, especially where HABs are occurring in less productive and less studied waterbodies. Here, the characteristics and annual dynamics of
Authors
Christina Amy Murphy, Amanda M.M. Pollock, Ivan Arismendi, Sherri L. Johnson
Comparing reintroduction strategies for the endangered San Francisco gartersnake (Thamnophis sirtalis tetrataenia) using demographic models Comparing reintroduction strategies for the endangered San Francisco gartersnake (Thamnophis sirtalis tetrataenia) using demographic models
For endangered species persisting in a few populations, reintroductions to unoccupied habitat are a popular conservation action to increase viability in the long term. Identifying the reintroduction strategy that is most likely to result in viable founder and donor populations is essential to optimally use resources available for conservation. The San Francisco gartersnake (Thamnophis...
Authors
Jonathan P. Rose, Richard Kim, Elliot James Schoenig, Patrick C. Lien, Brian J. Halstead
Geochemical evidence for evolving Proterozoic crustal thickness and orogenic styles in southwestern Laurentia Geochemical evidence for evolving Proterozoic crustal thickness and orogenic styles in southwestern Laurentia
It has long been challenging for researchers to track the crustal thickness and mode(s) of crustal modification in ancient convergent margins, limiting evaluation of the tectonic styles and processes that modify continental crust during orogenesis. We present trace element igneous geochemical crustal thickness proxies that quantitatively track the crustal thickness evolution of the long...
Authors
Ian William Hillenbrand, Karl E. Karlstrom, Michael L. Williams, Amy K. Gilmer, Wayne R. Premo, Peter B Davis
Lessons learned from the 2022 CONVERSE Monogenetic Volcanism Response Scenario exercise Lessons learned from the 2022 CONVERSE Monogenetic Volcanism Response Scenario exercise
When volcanic unrest occurs, the scientific community can advance fundamental understanding of volcanic systems, but only with coordination before, during, and after the event across academic and governmental agencies. To develop a coordinated response plan, the Community Network for Volcanic Eruption Response (CONVERSE) orchestrated a scenario exercise centered around a hypothetical...
Authors
Yolanda C Lin, Einat Lev, Ria Mukerji, Tobias P. Fischer, Charles B. Connor, Wendy K. Stovall, Michael Poland, Alexandra M. Iezzi, Christelle Wauthier, Judit Gonzalez-Santana, Heather M. Wright, Samantha Wolf, Tobi Kasali