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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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Changes in organic carbon source and storage with sea level rise-induced transgression in a Chesapeake Bay marsh Changes in organic carbon source and storage with sea level rise-induced transgression in a Chesapeake Bay marsh

Organic matter (OM) accumulation in marsh soils affects marsh survival under rapid sea-level rise (SLR). This work describes the changing organic geochemistry of a salt marsh located in the Blackwater National Wildlife Refuge on the eastern shore of Chesapeake Bay that has transgressed inland with SLR over the past 35–75 years. Marsh soils and vegetation were sampled along an elevation...
Authors
Rachel Van Allen, Kathryn M. Schreiner, Glenn R. Guntenspergen, Joseph A. Carlin

Assessing potential stock structure of adult Coho Salmon in a small Alaska watershed: Quantifying run timing, spawning locations, and holding areas with radiotelemetry Assessing potential stock structure of adult Coho Salmon in a small Alaska watershed: Quantifying run timing, spawning locations, and holding areas with radiotelemetry

Run timing and spatial locations of spawning habitats are often used to identify stocks for conservation planning or management of salmonid fishes. Although complex stock structure is most common within large watersheds with diverse habitats, even small drainages can produce multiple co-occurring spatially or temporally isolated populations or “stocks.” This project sought to address the...
Authors
M. E. Stratton, H. Finkle, Jeffrey A. Falke, P. A. H. Westley

Dynamics of green and blue water supply stress index across major global cropland basins Dynamics of green and blue water supply stress index across major global cropland basins

Global food and water insecurity could be serious problems in the upcoming decades with growing demands from the increasing global population and more frequent effect of climatic extremes. As the available water resources are diminishing and facing continuous stress, it is crucial to monitor water demand and water availability to understand the associated water stresses. This study...
Authors
Kul Bikram Khand, Gabriel B. Senay, Stefanie Kagone, Gabriel Edwin Lee Parrish

Integrating telemetry data at several scales with spatial capture–recapture to improve density estimates Integrating telemetry data at several scales with spatial capture–recapture to improve density estimates

Accurate population estimates are essential for monitoring and managing wildlife populations. Mark–recapture sampling methods have regularly been used to estimate population parameters for rare and cryptic species, including the federally listed Mojave desert tortoise (Gopherus agassizii); however, the methods employed are often plagued by violations of statistical assumptions, which...
Authors
Corey I Mitchell, Kevin T. Shoemaker, Todd Esque, Amy G. Vandergast, Steven J. Hromada, Kirsten E. Dutcher, Jill S. Heaton, Kenneth E. Nussear

Holocene hydroclimatic reorganizations in northwest Canada inferred from lacustrine carbonate oxygen isotopes Holocene hydroclimatic reorganizations in northwest Canada inferred from lacustrine carbonate oxygen isotopes

Sub-centennial oxygen (δ18O) isotopes of ostracod and authigenic calcite from Squanga Lake provides evidence of hydroclimatic extremes and a series of post-glacial climate system reorganizations for the interior region of northwest Canada. Authigenic calcite δ18O values range from −16‰ to −21‰ and are presently similar to modern lake water and annual precipitation values. Ostracod δ18O...
Authors
G. Everett Lasher, Mark B. Abbott, Lesleigh Anderson, Lindsey Yasarer, Michael Rosenheimer, Bruce P. Finney

Corticosterone mediates a growth-survival tradeoff for an amphibian exposed to increased salinity Corticosterone mediates a growth-survival tradeoff for an amphibian exposed to increased salinity

Life-history tradeoffs are common across taxa, but growth-survival tradeoffs—usually enhancing survival at a cost to growth—are less frequently investigated. Increased salinity (NaCl) is a prevalent anthropogenic disturbance that may cause a growth-survival tradeoff for larval amphibians. Although physiological mechanisms mediating tradeoffs are seldom investigated, hormones are prime...
Authors
BJ Tornabene, Blake R. Hossack, EJ Crespi, CW Breuner

Hawai‘i forest review: Synthesizing the ecology, evolution, and conservation of a model system Hawai‘i forest review: Synthesizing the ecology, evolution, and conservation of a model system

As the most remote archipelago in the world, the Hawaiian Islands are home to a highly endemic and disharmonic biota that has fascinated biologists for centuries. Forests are the dominant terrestrial biome in Hawai‘i, spanning complex, heterogeneous climates across substrates that vary tremendously in age, soil structure, and nutrient availability. Species richness is low in Hawaiian...
Authors
Kasey Barton, Andrea Westerband, Rebecca Ostertag, Elizabeth Stacy, Kawika Winter, Don Drake, Lucas Berio Fortini, Creighton M Litton, Susan Cordell, Paul Krushelnycky, Kapua Kawelo, Kealoha Feliciano, Gordon Bennett, Tiffany Knight

Improving evaluation of nonlethal tools for carnivore management and conservation: Evaluating fladry to protect an endangered species from a generalist mesocarnivore Improving evaluation of nonlethal tools for carnivore management and conservation: Evaluating fladry to protect an endangered species from a generalist mesocarnivore

Carnivore conservation and management are global research priorities focused on reversing population declines of imperiled species and identifying more effective and humane management of generalist carnivores with thriving populations. Nonlethal methods to mitigate conflict are increasingly used to advance conservation objectives; however, there is limited knowledge about the...
Authors
Rebecca Windell, Larissa L. Bailey, Julie K. Young, Travis M. Livieri, David A. Eads, Stewart Breck

Evaluating the migration mortality hypothesis using monarch tagging data Evaluating the migration mortality hypothesis using monarch tagging data

The decline in the eastern North American population of the monarch butterfly population since the late 1990s has been attributed to the loss of milkweed during the summer breeding season and the consequent reduction in the size of the summer population that migrates to central Mexico to overwinter (milkweed limitation hypothesis). However, in some studies the size of the summer...
Authors
Orley R. Taylor, John M. Pleasants, Ralph Grundel, Samuel Pecoraro, James P. Lovett, Ann Ryan

Diet composition of Fishers (Pekania pennanti) reintroduced on the Olympic Peninsula, Washington Diet composition of Fishers (Pekania pennanti) reintroduced on the Olympic Peninsula, Washington

Knowledge of diet composition can inform management strategies and efforts to recover endangered carnivore populations in vacant portions of their historic ranges. One such species, the Fisher (Pekania pennanti), was extirpated in Washington State prior to any formal documentation of its food habits in the coastal coniferous forests of western Washington. Fisher recovery efforts in...
Authors
Patricia J. Happe, Shelby H. Pace, Laura R. Prugh, Kurt Jenkins, Jeffrey C. Lewis, Joan Hagar

Brown treesnake mortality after aerial application of toxic baits Brown treesnake mortality after aerial application of toxic baits

Quantitative evaluation of control tools for managing invasive species is necessary to assess overall effectiveness and individual variation in treatment susceptibility. Invasive brown treesnakes (Boiga irregularis) on Guam have caused severe ecological and economic effects, pose a risk of accidental introduction to other islands, and are the greatest impediment to the reestablishment of
Authors
Scott Michael Goetz, Eric T. Hileman, Melia G. Nafus, Amy A. Yackel Adams, Amanda R Bryant, Robert Reed, Shane R. Siers

Integrating ecosystem metabolism and consumer allochthony reveals nonlinear drivers in lake organic matter processing Integrating ecosystem metabolism and consumer allochthony reveals nonlinear drivers in lake organic matter processing

Lakes process both terrestrial and aquatic organic matter, and the relative contribution from each source is often measured via ecosystem metabolism and terrestrial resource use in the food web (i.e., consumer allochthony). Yet, ecosystem metabolism and consumer allochthony are rarely considered together, despite possible interactions and potential for them to respond to the same lake
Authors
Meredith A. Holgerson, Rachel A. Hovel, Patrick T. Kelly, Lauren E Bortolotti, Jennifer A. Brentrup, Amber R Bellamy, Samantha K. Oliver, Alexander J Reisenger
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