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Maternal transfer of contaminants in birds: Mercury and selenium concentrations in parents and their eggs
We conducted a detailed assessment of the maternal transfer of mercury and selenium to eggs in three bird species (n = 107 parents and n = 339 eggs), and developed predictive equations linking contaminant concentrations in eggs to those in six tissues of the mother (blood, muscle, liver, kidney, breast feathers, and head...Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark P.; Hartman, C. Alex
Mercury transformation and release differs with depth and time in a contaminated riparian soil during simulated flooding
Riparian soils are an important environment in the transport of mercury in rivers and wetlands, but the biogeochemical factors controlling mercury dynamics under transient redox conditions in these soils are not well understood. Mercury release and transformations in the Oa and underlying A horizons of a contaminated riparian soil were...Poulin, Brett; Aiken, George R.; Nagy, Kathryn L.; Manceau, Alain; Krabbenhoft, David P.; Ryan, Joseph N.
Surface-air mercury fluxes across Western North America: A synthesis of spatial trends and controlling variables
Mercury (Hg) emission and deposition can occur to and from soils, and are an important component of the global atmospheric Hg budget. This paper focuses on synthesizing existing surface-air Hg flux data collected throughout the Western North American region and is part of a series of geographically focused Hg synthesis projects. A database of...Eckley, Chris S.; Tate, Michael T.; Lin, Che-Jen; Gustin, Mae S.; Dent, Stephen; Eagles-Smith, Collin A.; Lutz, Michelle A; Wickland, Kimberly; Wang, Bronwen; Gray, John E.; Edwards, Grant; Krabbenhoft, David P.; Smith, David
Introduction Groundwater represents the terrestrial subsurface component of the hydrologic cycle. As such, groundwater is generally in motion, moving from elevated areas of recharge to lower areas of discharge. Groundwater usually moves in accordance with Darcy’s law (Dalmont, Paris: Les Fontaines Publiques de la Ville de Dijon, 1856)....Wohl, Ellen E.; Stonestrom, David A.
Hydraulic and biochemical gradients limit wetland mercury supply to an Adirondack stream
Net fluxes (change between upstream and downstream margins) for water, methylmercury (MeHg), total mercury (THg), dissolved organic carbon (DOC), and chloride (Cl) were assessed twice in an Adirondack stream reach (Sixmile Brook, USA), to test the hypothesized importance of wetland-stream hydraulic and chemical gradients as fundamental controls on...Bradley, Paul M.; Burns, Douglas A.; Harvey, Judson; Journey, Celeste A.; Brigham, Mark E.; Murray, Karen
Experimental studies and model analysis of noble gas fractionation in porous media
The noble gases, which are chemically inert under normal terrestrial conditions but vary systematically across a wide range of atomic mass and diffusivity, offer a multicomponent approach to investigating gas dynamics in unsaturated soil horizons, including transfer of gas between saturated zones, unsaturated zones, and the atmosphere. To evaluate...Ding, Xin; Kennedy, B. Mack.; Evans, William C.; Stonestrom, David A.
Mercury remediation in wetland sediment using zero-valent iron and granular activated carbon
Wetlands are hotspots for production of toxic methylmercury (MeHg) that can bioaccumulate in the food web. The objective of this study was to determine whether the application of zero-valent iron (ZVI) or granular activated carbon (GAC) to wetland sediment could reduce MeHg production and bioavailability to benthic organisms. Field mesocosms were...Lewis, Ariel S.; Huntington, Thomas G.; Marvin-DiPasquale, Mark C.; Amirbahman, Aria
Bioaccessibility tests accurately estimate bioavailability of lead to quail
Hazards of soil-borne Pb to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, we measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison...Beyer, W. Nelson; Basta, Nicholas T; Chaney, Rufus L.; Henry, Paula F. P.; Mosby, David; Rattner, Barnett A.; Scheckel, Kirk G.; Sprague, Dan; Weber, John
Spatial and temporal variation in microcystins occurrence in wadeable streams in the southeastern USA
Despite historical observations of potential microcystin-producing cyanobacteria (including Leptolyngbya,Phormidium, Pseudoanabaena, and Anabaena species) in 74% of headwater streams in Alabama, Georgia, South Carolina, and North Carolina (USA) from 1993 to 2011, fluvial cyanotoxin occurrence has not been systematically assessed in the...Loftin, Keith A.; Clark, Jimmy M.; Journey, Celeste A.; Kolpin, Dana W.; Van Metre, Peter C.; Bradley, Paul M.
Evaluating a portable cylindrical bait trap to capture diamondback terrapins in salt marsh
Diamondback terrapins (Malaclemys terrapin) are currently in decline across much of their historical range, and demographic data on a regional scale are needed to identify where their populations are at greatest risk. Because terrapins residing in salt marshes are difficult to capture, we designed a cylindrical bait trap (CBT) that could be...Henry, Paula F. P.; Haramis, G. Michael; Day, Daniel D.
Dietary uptake of Cu sorbed to hydrous iron oxide is linked to cellular toxicity and feeding inhibition in a benthic grazer
Whereas feeding inhibition caused by exposure to contaminants has been extensively documented, the underlying mechanism(s) are less well understood. For this study, the behavior of several key feeding processes, including ingestion rate and assimilation efficiency, that affect the dietary uptake of Cu were evaluated in the benthic grazer ...Cain, Daniel J.; Croteau, Marie-Noele; Fuller, Christopher C.; Ringwood, Amy H.
From tails to toes: developing nonlethal tissue indicators of mercury exposure in five amphibian species
Exposure to environmental contaminants has been implicated as a factor in global amphibian decline. Mercury (Hg) is a particularly widespread contaminant that biomagnifies in amphibians and can cause a suite of deleterious effects. However, monitoring contaminant exposure in amphibian tissues may conflict with conservation goals if lethal take is...Pfleeger, Adam Z.; Eagles-Smith, Collin A.; Kowalski, Brandon M.; Herring, Garth; Willacker, James J.; Jackson, Allyson K.; Pierce, John
U.S. Geological Survey (USGS) scientists conducted a unique study, which demonstrated that the ecology of natural groundwater bacteria changed after exposure of the bacteria to the antibiotic sulfamethoxazole (SMX). The study was conducted within the zone of the historic wastewater-contamination plume at the...
Remnants of a spruce forest complex following a severe wildfire in the Yukon Flats National Wildlife Refuge, Alaska. Wildfires are the dominant landscape-scale disturbance operating at annual time scales in Alaska, and fires play a major role in the rate and extent of vegetation growth and productivity of a site. Wildland fires typically result in the reduction of...
Neal Pastick – lead author of the study – investigating erosion along Alaska’s Arctic coastline near the village of Kaktovik. Permafrost-dominated coasts of Alaska have drastically changed as the result of coastal transgression and storm-surge flooding which can result in the loss of cultural sites and damage to infrastructure. Photo by M. Torre Jorgenson...
USGS scientist collecting a water sample from the stream prior to the swine manure spill.
USGS scientists collecting water-quality samples for the analysis of wastewater related contaminants, Boulder Creek, Colorado.
Environmental Chemistry Laboratory — Columbia, Missouri. Customized extraction system