Now showing items 222-241 of 868

    • Divergent responses of Atlantic coastal and oceanic Synechococcus to iron limitation 

      Mackey, Katherine R. M.; Post, Anton F.; McIlvin, Matthew R.; Cutter, Gregory A.; John, Seth G.; Saito, Mak A. (2015-06-19)
      Marine Synechococcus are some of the most diverse and ubiquitous phytoplankton, and iron (Fe) is an essential micronutrient that limits productivity in many parts of the ocean. To investigate how coastal and oceanic Atlantic ...
    • Diverse styles of submarine venting on the ultraslow spreading Mid-Cayman Rise 

      German, Christopher R.; Bowen, Andrew D.; Coleman, M. L.; Honig, D. L.; Huber, Julie A.; Jakuba, Michael V.; Kinsey, James C.; Kurz, Mark D.; Leroy, S.; McDermott, Jill M.; Mercier de Lepinay, B.; Nakamura, Ko-ichi; Seewald, Jeffrey S.; Smith, J. L.; Sylva, Sean P.; Van Dover, Cindy L.; Whitcomb, Louis L.; Yoerger, Dana R. (2010-06-24)
      Thirty years after the first discovery of high-temperature submarine venting, the vast majority of the global Mid Ocean Ridge remains unexplored for hydrothermal activity. Of particular interest are the world’s ultra-slow ...
    • Diversity and spatial distribution of hydrazine oxidoreductase (hzo) gene in the oxygen minimum zone off Costa Rica 

      Kong, Liangliang; Jing, Hongmei; Kataoka, Takafumi; Buchwald, Carolyn; Liu, Hongbin (Public Library of Science, 2013-10-31)
      Anaerobic ammonia oxidation (anammox) as an important nitrogen loss pathway has been reported in marine oxygen minimum zones (OMZs), but the community composition and spatial distribution of anammox bacteria in the eastern ...
    • Diversity of Archaea and detection of crenarchaeotal amoA genes in the rivers Rhine and Têt 

      Herfort, Lydie; Kim, Jung-Hyun; Coolen, Marco J. L.; Abbas, Ben; Schouten, Stefan; Herndl, Gerhard J.; Sinninghe Damste, Jaap S. (Inter-Research, 2009-04-28)
      Pelagic archaeal phylogenetic diversity and the potential for crenarchaeotal nitrification of Group 1.1a were determined in the rivers Rhine and Têt by 16S rRNA sequencing, catalyzed reported deposition-fluorescence in ...
    • Does a ballast effect occur in the surface ocean? 

      Sanders, Richard J.; Morris, Paul J.; Poulton, Alex J.; Stinchcombe, Mark C.; Charalampopoulou, Anastasia; Lucas, Mike I.; Thomalla, Sandy J. (American Geophysical Union, 2010-04-29)
      The oceanic biological carbon pump (BCP), a large (10 GT C yr−1) component of the global carbon cycle, is dominated by the sinking (export) of particulate organic carbon (POC) from surface waters. In the deep ocean, strong ...
    • Drifter-based estimate of the 5 year dispersal of Fukushima-derived radionuclides 

      Rypina, Irina I.; Jayne, Steven R.; Yoshida, Sachiko; Macdonald, Alison M.; Buesseler, Ken O. (John Wiley & Sons, 2014-11-28)
      Employing some 40 years of North Pacific drifter-track observations from the Global Drifter Program database, statistics defining the horizontal spread of radionuclides from Fukushima nuclear power plant into the Pacific ...
    • Drivers and uncertainties of future global marine primary production in marine ecosystem models 

      Laufkotter, Charlotte; Vogt, Meike; Gruber, Nicolas; Aita-Noguchi, M.; Aumont, Olivier; Bopp, Laurent; Buitenhuis, Erik T.; Doney, Scott C.; Dunne, John P.; Hashioka, Taketo; Hauck, Judith; Hirata, Takafumi; John, Jasmin G.; Le Quere, Corinne; Lima, Ivan D.; Nakano, Hideyuki; Seferian, Roland; Totterdell, Ian J.; Vichi, Marcello; Volker, Chrisoph (Copernicus Publications on behalf of the European Geosciences Union, 2015-12-07)
      Past model studies have projected a global decrease in marine net primary production (NPP) over the 21st century, but these studies focused on the multi-model mean rather than on the large inter-model differences. Here, ...
    • Drought, agricultural adaptation, and sociopolitical collapse in the Maya Lowlands 

      Douglas, Peter M. J.; Pagani, Mark; Canuto, Marcello A.; Brenner, Mark; Hodell, David A.; Eglinton, Timothy I.; Curtis, Jason H. (2014-10)
      Paleoclimate records indicate a series of severe droughts was associated with societal collapse of the Classic Maya during the Terminal Classic period (approximately 800 to 950 CE). Evidence for drought largely derives ...
    • Dual isotope analyses indicate efficient processing of atmospheric nitrate by forested watersheds in the northeastern U.S. 

      Barnes, Rebecca T.; Raymond, Peter A.; Casciotti, Karen L. (2008-07-15)
      Nitrogen from atmospheric deposition serves as the dominant source of new nitrogen to forested ecosystems in the northeastern U.S.. By combining isotopic data obtained using the denitrifier method, with chemistry and ...
    • A dual sensor device to estimate fluid flow velocity at diffuse hydrothermal vents 

      Sarrazin, J.; Rodier, P.; Tivey, Margaret K.; Singh, Hanumant; Schultz, A.; Sarradin, Pierre-Marie (2009-06-12)
      Numerous attempts have been made over the last thirty years to estimate fluid flow rates at hydrothermal vents, either at the exit of black smoker chimneys or within diffuse flow areas. In this study, we combine two ...
    • Dynamic intermediate ocean circulation in the North Atlantic during Heinrich Stadial 1 : a radiocarbon and neodymium isotope perspective 

      Wilson, David J.; Crocket, Kirsty C.; van de Flierdt, Tina; Robinson, Laura F.; Adkins, Jess F. (John Wiley & Sons, 2014-11-20)
      The last deglaciation was characterized by a series of millennial-scale climate events that have been linked to deep ocean variability. While often implied in interpretations, few direct constraints exist on circulation ...
    • Dynamics of particulate organic carbon flux in a global ocean model 

      Lima, Ivan D.; Lam, Phoebe J.; Doney, Scott C. (Copernicus Publications on behalf of the European Geosciences Union, 2014-02-27)
      The sinking of particulate organic carbon (POC) is a key component of the ocean carbon cycle and plays an important role in the global climate system. However, the processes controlling the fraction of primary production ...
    • Early anthropogenic transformation of the Danube-Black Sea system 

      Giosan, Liviu; Coolen, Marco J. L.; Kaplan, Jed O.; Constantinescu, Stefan; Filip, Florin; Filipova-Marinova, Mariana; Kettner, Albert J.; Thom, Nick (Nature Publishing Group, 2012-08-30)
      Over the last century humans have altered the export of fluvial materials leading to significant changes in morphology, chemistry, and biology of the coastal ocean. Here we present sedimentary, paleoenvironmental and ...
    • Early season depletion of dissolved iron in the Ross Sea polynya : implications for iron dynamics on the Antarctic continental shelf 

      Sedwick, Peter N.; Marsay, Christopher M.; Sohst, Bettina M.; Aguilar-Islas, Ana M.; Lohan, M. C.; Long, Matthew C.; Arrigo, Kevin R.; Dunbar, Robert B.; Saito, Mak A.; Smith, Walker O.; DiTullio, Giacomo R. (American Geophysical Union, 2011-12-15)
      The Ross Sea polynya is among the most productive regions in the Southern Ocean and may constitute a significant oceanic CO2 sink. Based on results from several field studies, this region has been considered seasonally ...
    • Ecosystem development after mangrove wetland creation : plant–soil change across a 20-year chronosequence 

      Osland, Michael J.; Spivak, Amanda C.; Nestlerode, Janet A.; Lessmann, Jeannine M.; Almario, Alejandro E.; Heitmuller, Paul T.; Russell, Marc J.; Krauss, Ken W.; Alvarez, Federico; Dantin, Darrin D.; Harvey, James E.; From, Andrew S.; Cormier, Nicole; Stagg, Camille L. (Springer, 2012-05-19)
      Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland losses. However, ecosystem development and functional equivalence in restored and created mangrove ...
    • Eddy-resolving simulation of plankton ecosystem dynamics in the California Current System 

      Gruber, Nicolas; Frenzel, Hartmut; Doney, Scott C.; Marchesiello, Patrick; McWilliams, James C.; Moisan, John R.; Oram, John J.; Plattner, Gian-Kasper; Stolzenbach, Keith D. (2006-06-13)
      We study the dynamics of the planktonic ecosystem in the coastal upwelling zone within the California Current System using a three-dimensional, eddy-resolving circulation model coupled to an ecosystem/biogeochemistry ...
    • Effect of carbon addition and predation on acetate-assimilating bacterial cells in groundwater 

      Longnecker, Krista; Da Costa, Andreia; Bhatia, Maya P.; Kujawinski, Elizabeth B. (2009-07-13)
      Groundwater microbial community dynamics are poorly understood due to the challenges associated with accessing subsurface environments. In particular, microbial interactions and their impact on the subsurface carbon cycle ...
    • Effect of continental shelf canyons on phytoplankton biomass and community composition along the western Antarctic Peninsula 

      Kavanaugh, Maria T.; Abdala, F. N.; Ducklow, Hugh W.; Glover, David M.; Fraser, William R.; Martinson, Douglas G.; Stammerjohn, Sharon E.; Schofield, Oscar M. E.; Doney, Scott C. (Inter-Research, 2015-03-30)
      The western Antarctic Peninsula is experiencing dramatic climate change as warm, wet conditions expand poleward and interact with local physics and topography, causing differential regional effects on the marine ecosystem. ...
    • Effect of field exposure to 38-year-old residual petroleum hydrocarbons on growth, condition index, and filtration rate of the ribbed mussel, Geukensia demissa 

      Culbertson, Jennifer B.; Valiela, Ivan; Olsen, Ylva S.; Reddy, Christopher M. (2007-10-06)
      In September 1969, the Florida barge spilled 700,000 L of No. 2 fuel oil into the salt marsh sediments of Wild Harbor, MA. Today a substantial amount, approximately 100 kg, of moderately degraded petroleum remains within ...
    • The effect of nutrients on carbon and nitrogen fixation by the UCYN-A–haptophyte symbiosis 

      Krupke, Andreas; Mohr, Wiebke; LaRoche, Julie; Fuchs, Bernhard M.; Amann, Rudolf I.; Kuypers, Marcel M. M. (2014-11-19)
      Symbiotic relationships between phytoplankton and N2-fixing microorganisms play a crucial role in marine ecosystems. The abundant and widespread unicellular cyanobacteria group A (UCYN-A) has recently been found to live ...