Publications
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Filter Total Items: 205
Obtaining parsimonious hydraulic conductivity fields using head and transport observations: A Bayesian geostatistical parameter estimation approach Obtaining parsimonious hydraulic conductivity fields using head and transport observations: A Bayesian geostatistical parameter estimation approach
Flow path delineation is a valuable tool for interpreting the subsurface hydrogeochemical environment. Different types of data, such as groundwater flow and transport, inform different aspects of hydrogeologic parameter values (hydraulic conductivity in this case) which, in turn, determine flow paths. This work combines flow and transport information to estimate a unified set of...
Authors
Michael N. Fienen, R. Hunt, D. Krabbenhoft, T. Clemo
Methylmercury enters an aquatic food web through acidophilic microbial mats in Yellowstone National Park, Wyoming Methylmercury enters an aquatic food web through acidophilic microbial mats in Yellowstone National Park, Wyoming
Microbial mats are a visible and abundant life form inhabiting the extreme environments in Yellowstone National Park (YNP), WY, USA. Little is known of their role in food webs that exist in the Park's geothermal habitats. Eukaryotic green algae associated with a phototrophic green/purple Zygogonium microbial mat community that inhabits low-temperature regions of acidic (pH ∼ 3.0) thermal...
Authors
Eric S. Boyd, S. King, J.K. Tomberlin, D. Kirk Nordstrom, D. P. Krabbenhoft, T. Barkay, G. G. Geesey
Mercury cycling in stream ecosystems. 1. Water column chemistry and transport Mercury cycling in stream ecosystems. 1. Water column chemistry and transport
We studied total mercury (THg) and methylmercury (MeHg) in eight streams, located in Oregon, Wisconsin, and Florida, that span large ranges in climate, landscape characteristics, atmospheric Hg deposition, and water chemistry. While atmospheric deposition was the source of Hg at each site, basin characteristics appeared to mediate this source by providing controls on methylation and...
Authors
M. E. Brigham, D.A. Wentz, G. R. Aiken, D. P. Krabbenhoft
Geological, geochemical, and geophysical studies by the U.S. Geological Survey in Big Bend National Park, Texas Geological, geochemical, and geophysical studies by the U.S. Geological Survey in Big Bend National Park, Texas
Big Bend National Park (BBNP), Tex., covers 801,163 acres (3,242 km2) and was established in 1944 through a transfer of land from the State of Texas to the United States. The park is located along a 118-mile (190-km) stretch of the Rio Grande at the United States-Mexico border. The park is in the Chihuahuan Desert, an ecosystem with high mountain ranges and basin environments containing...
Authors
W. R. Page, K. J. Turner, R. G. Bohannon, M. E. Berry, V. S. Williams, D. P. Miggins, M. Ren, E. Y. Anthony, L. A. Morgan, P. W. C. Shanks, J. E. Gray, P. M. Theodorakos, David P. Krabbenhoft, A. H. Manning, P. A. Gemery-Hill, E. C. Hellgren, C. A. Stricker, D. P. Onorato, C. A. Finn, E. Anderson
Total mercury, methylmercury, methylmercury production potential, and ancillary streambed-sediment and pore-water data for selected streams in Oregon, Wisconsin, and Florida, 2003-04 Total mercury, methylmercury, methylmercury production potential, and ancillary streambed-sediment and pore-water data for selected streams in Oregon, Wisconsin, and Florida, 2003-04
Mercury contamination of aquatic ecosystems is an issue of national concern, affecting both wildlife and human health. Detailed information on mercury cycling and food-web bioaccumulation in stream settings and the factors that control these processes is currently limited. In response, the U.S. Geological Survey (USGS) National Water-Quality Assessment Program (NAWQA) conducted detailed...
Authors
Mark C. Marvin-DiPasquale, Michelle A. Lutz, David P. Krabbenhoft, George R. Aiken, William H. Orem, Britt D. Hall, John F. DeWild, Mark E. Brigham
White sturgeon mitigation and restoration in the Columbia and Snake rivers upstream from Bonneville Dam, Annual Progress Report April 2006 - March 2007. Report C White sturgeon mitigation and restoration in the Columbia and Snake rivers upstream from Bonneville Dam, Annual Progress Report April 2006 - March 2007. Report C
Describe reproduction and early life history characteristics of white sturgeon populations in the Columbia River between Bonneville and Priest Rapids dams. Define habitat requirements for spawning and rearing white sturgeon and quantify the extent of habitat available in the Columbia River between Bonneville and Priest Rapids dams. Progress updates on young-of-the-year recruitment in...
Authors
M.J. Parsley, P. Kofoot
Comparison of total mercury and methylmercury cycling at five sites using the small watershed approach Comparison of total mercury and methylmercury cycling at five sites using the small watershed approach
The small watershed approach is well-suited but underutilized in mercury research. We applied the small watershed approach to investigate total mercury (THg) and methylmercury (MeHg) dynamics in streamwater at the five diverse forested headwater catchments of the US Geological Survey Water, Energy, and Biogeochemical Budgets (WEBB) program. At all sites, baseflow THg was generally less...
Authors
J. B. Shanley, Mast M. Alisa, K. Campbell, G. R. Aiken, D. P. Krabbenhoft, R. J. Hunt, J.F. Walker, P. F. Schuster, A. Chalmers, Brent T. Aulenbach, N.E. Peters, M. Marvin-DiPasquale, D. W. Clow, M.M. Shafer
Influence of natural dissolved organic carbon on the bioavailability of mercury to a freshwater alga Influence of natural dissolved organic carbon on the bioavailability of mercury to a freshwater alga
Bioavailability of mercury (Hg) to Selenastrum capricornutum was assessed in bioassays containing field-collected freshwater of varying dissolved organic carbon (DOC) concentrations. Bioconcentration factor (BCF) was measured using stable isotopes of methylmercury (MeHg) and inorganic Hg(II). BCFs for MeHg in low-DOC lake water were significantly larger than those in mixtures of lake...
Authors
P.R. Gorski, D.E. Armstrong, J.P. Hurley, D. P. Krabbenhoft
A comparison of winter mercury accumulation at forested and no-canopy sites measured with different snow sampling techniques A comparison of winter mercury accumulation at forested and no-canopy sites measured with different snow sampling techniques
Atmospheric mercury (Hg) is delivered to ecosystems via rain, snow, cloud/fog, and dry deposition. The importance of snow, especially snow that has passed through the forest canopy (throughfall), in delivering Hg to terrestrial ecosystems has received little attention in the literature. The snowpack is a dynamic system that links atmospheric deposition and ecosystem cycling through...
Authors
S.J. Nelson, K.B. Johnson, K.C. Weathers, C.S. Loftin, I.J. Fernandez, J. S. Kahl, D. P. Krabbenhoft
Mercury, trace elements and organic constituents in atmospheric fine particulate matter, Shenandoah National Park, Virginia, USA: A combined approach to sampling and analysis Mercury, trace elements and organic constituents in atmospheric fine particulate matter, Shenandoah National Park, Virginia, USA: A combined approach to sampling and analysis
Compliance with U.S. air quality regulatory standards for atmospheric fine particulate matter (PM2.5) is based on meeting average 24 hour (35 μ m−3) and yearly (15 μg m−3) mass‐per‐unit‐volume limits, regardless of PM2.5 composition. Whereas this presents a workable regulatory framework, information on particle composition is needed to assess the fate and transport of PM2.5 and determine...
Authors
A. Kolker, M.A. Engle, W. H. Orem, J.E. Bunnell, H.E. Lerch, D. P. Krabbenhoft, M.L. Olson, J.D. McCord
Mercury and organic carbon dynamics during runoff episodes from a northeastern USA watershed Mercury and organic carbon dynamics during runoff episodes from a northeastern USA watershed
Mercury and organic carbon concentrations vary dynamically in streamwater at the Sleepers River Research Watershed in Vermont, USA. Total mercury (THg) concentrations ranged from 0.53 to 93.8 ng/L during a 3-year period of study. The highest mercury (Hg) concentrations occurred slightly before peak flows and were associated with the highest organic carbon (OC) concentrations. Dissolved...
Authors
P. F. Schuster, J. B. Shanley, M. Marvin-DiPasquale, M.M. Reddy, G. R. Aiken, D.A. Roth, Howard E. Taylor, D. P. Krabbenhoft, J.F. DeWild
Wetlands as principal zones of methylmercury production in southern Louisiana and the Gulf of Mexico region Wetlands as principal zones of methylmercury production in southern Louisiana and the Gulf of Mexico region
It is widely recognized that wetlands, especially those rich in organic matter and receiving appreciable atmospheric mercury (Hg) inputs, are important sites of methylmercury (MeHg) production. Extensive wetlands in the southeastern United States have many ecosystem attributes ideal for promoting high MeHg production rates; however, relatively few mercury cycling studies have been...
Authors
B.D. Hall, G. R. Aiken, D. P. Krabbenhoft, M. Marvin-DiPasquale, C.M. Swarzenski