Now showing items 1-20 of 28

    • Aqueous phase methylation as a potential source of methylmercury in wet deposition 

      Hammerschmidt, Chad R.; Lamborg, Carl H.; Fitzgerald, William F. (2006-10-17)
      The source of monomethylmercury (MMHg) in wet deposition is unknown. Volatilization of gaseous MMHg, evasion and demethylation of dimethylmercury, and methylation of Hg0 have been either proposed or tested unsuccessfully ...
    • An assessment of particulate organic carbon to thorium-234 ratios in the ocean and their impact on the application of 234Th as a POC flux proxy 

      Buesseler, Ken O.; Benitez-Nelson, Claudia R.; Burd, Adrian B.; Charette, Matthew A.; Cochran, J. Kirk; Coppola, L.; Fisher, Nicholas S.; Fowler, S. W.; Gardner, Wilford D.; Guo, L. D.; Gustafsson, Orjan; Lamborg, Carl H.; Masque, Pere; Miquel, Juan Carlos; Passow, Uta; Santschi, Peter H.; Savoye, Nicolas; Stewart, G.; Trull, Thomas W. (2005-06-18)
      Thorium-234 is increasingly used as a tracer of ocean particle flux, primarily as a means to estimate particulate organic carbon export from the surface ocean. This requires determination of both the 234Th activity ...
    • Barium in twilight zone suspended matter as a potential proxy for particulate organic carbon remineralization : results for the North Pacific 

      Dehairs, Frank; Jacquet, S.; Savoye, Nicolas; Van Mooy, Benjamin A. S.; Buesseler, Ken O.; Bishop, James K. B.; Lamborg, Carl H.; Elskens, Marc; Baeyens, W.; Boyd, Philip W.; Casciotti, Karen L.; Monnin, C. (2008-01-22)
      This study focuses on the fate of exported organic carbon in the twilight zone at two contrasting environments in the North Pacific: the oligotrophic ALOHA site (22°45' N 158°W; Hawaii; studied during June–July 2004) and ...
    • Basin-scale inputs of cobalt, iron, and manganese from the Benguela-Angola front to the South Atlantic Ocean 

      Noble, Abigail E.; Lamborg, Carl H.; Ohnemus, Daniel C.; Lam, Phoebe J.; Goepfert, Tyler J.; Measures, Christopher I.; Frame, Caitlin H.; Casciotti, Karen L.; DiTullio, Giacomo R.; Jennings, Joe C.; Saito, Mak A. (Association for the Sciences of Limnology and Oceanography, 2012-07)
      We present full-depth zonal sections of total dissolved cobalt, iron, manganese, and labile cobalt from the South Atlantic Ocean. A basin-scale plume from the African coast appeared to be a major source of dissolved metals ...
    • Correction to “Mercury and monomethylmercury in fluids from Sea Cliff submarine hydrothermal field, Gorda Ridge” 

      Lamborg, Carl H.; Von Damm, Karen L.; Fitzgerald, William F.; Hammerschmidt, Chad R.; Zierenberg, Robert (American Geophysical Union, 2007-01-18)
    • Determination of monomethylmercury from seawater with ascorbic acid-assisted direct ethylation 

      Munson, Kathleen M.; Babi, Diana; Lamborg, Carl H. (Association for the Sciences of Limnology and Oceanography, 2014-01)
      We developed a technique to measure monomethylmercury (MMHg) concentrations from small volumes (180 mL) of seawater at low femtomolar concentrations using direct ethylation derivitization, decreasing the required volume ...
    • Environmental assessment of metal exposure to corals living in Castle Harbour, Bermuda 

      Grumet-Prouty, Nancy; Goodkin, Nathalie F.; Jones, R.; Lamborg, Carl H.; Storlazzi, Curt D.; Hughen, Konrad A. (Elsevier B.V., 2013-05-07)
      Environmental contamination in Castle Harbour, Bermuda, has been linked to the dissolution and leaching of contaminants from the adjacent marine landfill. This study expands the evidence for environmental impact of leachate ...
    • Increase in mercury in Pacific yellowfin tuna 

      Drevnick, Paul E.; Lamborg, Carl H.; Horgan, Martin J. (2015-01)
      Mercury is a toxic trace metal that can accumulate to levels that threaten human and environmental health. Models and empirical data suggest that humans are responsible for a great deal of the mercury actively cycling ...
    • Increased accumulation of sulfur in lake sediments of the high Arctic 

      Drevnick, Paul E.; Muir, Derek C. G.; Lamborg, Carl H.; Horgan, Martin J.; Canfield, Donald E.; Boyle, John F.; Rose, Neil L. (2010-08-31)
      We report a synchronous increase in accumulation of reduced inorganic sulfur since c. 1980 in sediment cores from eight of nine lakes studied in the Canadian Arctic and Svalbard (Norway). Sediment incubations and detailed ...
    • An intercomparison of procedures for the determination of total mercury in seawater and recommendations regarding mercury speciation during GEOTRACES cruises 

      Lamborg, Carl H.; Hammerschmidt, Chad R.; Gill, Gary A.; Mason, Robert P.; Gichuki, Susan (Association for the Sciences of Limnology and Oceanography, 2012-02)
      We conducted a laboratory intercomparison of total mercury (Hg) determination in seawater collected during U.S. GEOTRACES Intercalibration cruises in 2008 and 2009 to the NW Atlantic and NE Pacific Oceans. Results indicated ...
    • Mercury and monomethylmercury in fluids from Sea Cliff submarine hydrothermal field, Gorda Ridge 

      Lamborg, Carl H.; Von Damm, Karen L.; Fitzgerald, William F.; Hammerschmidt, Chad R.; Zierenberg, Robert (American Geophysical Union, 2006-09-09)
      Submarine hydrothermal systems are hypothesized to be a potentially important source of monomethylmercury (MMHg) to the ocean, yet the amount of MMHg in vent fluids is unknown. Here, we report total Hg and MMHg concentrations ...
    • Mercury contamination and cycling in the coastal zone 

      Balcom, Prentiss; Fitzgerald, William F.; Hammerschmidt, Chad R.; Lamborg, Carl H.; Visscher, Pieter T. (IAMSLIC, 2004)
    • Mercury flux to sediments of Lake Tahoe, California-Nevada 

      Drevnick, Paul E.; Shinneman, Avery L. C.; Lamborg, Carl H.; Engstrom, Daniel R.; Bothner, Michael H.; Oris, James T. (2009-08-12)
      We report estimates of mercury (Hg) flux to the sediments of Lake Tahoe, California-Nevada: 2 and 15-20 µg/m2/yr in preindustrial and modern sediments, respectively. These values result in a modern to preindustrial flux ...
    • Mercury in the anthropocene ocean 

      Lamborg, Carl H.; Bowman, Katlin; Hammerschmidt, Chad R.; Gilmour, Cindy; Munson, Kathleen M.; Selin, Noelle; Tseng, Chun-Mao (The Oceanography Society, 2014-03)
      The toxic metal mercury is present only at trace levels in the ocean, but it accumulates in fish at concentrations high enough to pose a threat to human and environmental health. Human activity has dramatically altered the ...
    • Mercury species concentrations and fluxes in the Central Tropical Pacific Ocean 

      Munson, Kathleen M.; Lamborg, Carl H.; Swarr, Gretchen J.; Saito, Mak A. (John Wiley & Sons, 2015-03-25)
      The formation of the toxic and bioaccumulating monomethylmercury (MMHg) in marine systems is poorly understood, due in part to sparse data from many ocean regions. We present dissolved mercury (Hg) speciation data from 10 ...
    • Methylmercury in marine ecosystems : spatial patterns and processes of production, bioaccumulation, and biomagnification 

      Chen, Celia; Amirbahman, Aria; Fisher, Nicholas S.; Harding, Gareth; Lamborg, Carl H.; Nacci, Diane E.; Taylor, David (2008-09-30)
      The spatial variation of MeHg production, bioaccumulation and biomagnification in marine food webs is poorly characterized but critical to understanding the links between sources and higher trophic levels such as fish ...
    • Microbial- and thiosulfate-mediated dissolution of mercury sulfide minerals and transformation to gaseous mercury 

      Vazquez-Rodriguez, Adiari I.; Hansel, Colleen M.; Zhang, Tong; Lamborg, Carl H.; Santelli, Cara M.; Webb, Samuel M.; Brooks, Scott C. (Frontiers Media, 2015-06-23)
      Mercury (Hg) is a toxic heavy metal that poses significant environmental and human health risks. Soils and sediments, where Hg can exist as the Hg sulfide mineral metacinnabar (β-HgS), represent major Hg reservoirs in ...
    • Net atmospheric mercury deposition to Svalbard : estimates from lacustrine sediments 

      Drevnick, Paul E.; Yang, Handong; Lamborg, Carl H.; Rose, Neil L. (2012-05)
      In this study we used lake sediments, which faithfully record Hg inputs, to derive estimates of net atmospheric Hg deposition to Svalbard, Norwegian Arctic. With the exception of one site affected by local pollution, ...
    • Particle fluxes associated with mesoscale eddies in the Sargasso Sea 

      Buesseler, Ken O.; Lamborg, Carl H.; Cai, Pinghe; Escoube, Raphaelle; Johnson, Rodney J.; Pike, Steven M.; Masque, Pere; McGillicuddy, Dennis J.; Verdeny, Elisabet (2007-09-25)
      We examined the impact of a cyclonic eddy and mode-water eddy on particle flux in the Sargasso Sea. The primary method used to quantify flux was based upon measurements of the natural radionuclide, 234Th, and these flux ...
    • Revisiting carbon flux through the ocean's twilight zone 

      Buesseler, Ken O.; Lamborg, Carl H.; Boyd, Philip W.; Lam, Phoebe J.; Trull, Thomas W.; Bidigare, Robert R.; Bishop, James K. B.; Casciotti, Karen L.; Dehairs, Frank; Elskens, Marc; Honda, Makio C.; Karl, David M.; Siegel, David A.; Silver, Mary W.; Steinberg, Deborah K.; Valdes, James R.; Van Mooy, Benjamin A. S.; Wilson, Stephanie E. (American Association for the Advancement of Science, 2007-04-27)