BN31B:
New Insights into Marine N2 Fixation: From Single Cells to Ecosystems I


Session ID#: 37141

Session Description:
The availability of combined nitrogen (N) influences the productivity of marine environments. The main source of N to the open ocean is biologically-mediated dinitrogen (N2) fixation. Our understanding of N2 fixation has greatly increased in the past two decades, including recognizing new habitats, new organisms, and new lifestyles of the microbes carrying out this process. Methodological developments and improvements, e.g., single-cell techniques and isotope tracer experiments, have enhanced our capabilities to better quantify bulk N2 fixation rates and to assess the contributions of individual organisms and the environmental regulation. Despite the known importance of N2 fixation for marine productivity, there is, however, still a lack of knowledge about which N2 fixers are biogeochemically relevant in most regions of the world ocean, how variable the activity is spatially and temporally, which factors influence the activity and distribution in the environment, and whether N2 fixation in the modern ocean can quantitatively account for oceanic N loss. This session invites contributions from biogeochemists, microbial ecologists, and oceanographers to share new insights on marine N2 fixation at the single-cell, population, ecosystem and global level including experimental, observation and modeling approaches.
Primary Chair:  Wiebke Mohr, Max Planck Institute for Marine Microbiology, Biogeochemistry, Bremen, Germany
Co-chairs:  Sven Alexander Kranz, Rice University, Department of Biosciences, Houston, United States and Angela N Knapp, Florida State University, Earth, Ocean, and Atmospheric Sciences, Tallahassee, FL, United States
Moderators:  Sven Alexander Kranz, Rice University, Department of Biosciences, Houston, United States and Angela N Knapp, Florida State University, Earth, Ocean, and Atmospheric Sciences, Tallahassee, FL, United States
Student Paper Review Liaison:  Sven Alexander Kranz, Rice University, Department of Biosciences, Houston, United States
Index Terms:

4805 Biogeochemical cycles, processes, and modeling [OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL]
4815 Ecosystems, structure, dynamics, and modeling [OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL]
4845 Nutrients and nutrient cycling [OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL]
4870 Stable isotopes [OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL]
Cross-Topics:
  • MM - Microbiology and Molecular Ecology
  • OM - Ocean Modeling
  • PC - Past, Present and Future Climate

Abstracts Submitted to this Session:

Diel regulation of photosynthetic activity in Crocosphaera (308672)
Ondřej Prášil, Takako Masuda, Gabor Bernat, Martina Beckova, Eva Kotabova, Evelyn Lawrenz, Martin Lukes and Josef Komenda, Institute of Microbiology, Czech Academy of Sciences, Center Algatech, Třeboň, Czech Republic
Distribution of the Nitrogen Fixing, Cyanobacterial Symbiont UCYN-A in the Chukchi and Beaufort Seas (319983)
Katie Jean Harding1, Kendra Turk-Kubo1, Rachel E Sipler2, Deborah Ann Bronk3 and Jonathan P Zehr1, (1)University of California Santa Cruz, Ocean Sciences, Santa Cruz, CA, United States, (2)Virginia Institute of Marine Science, Gloucester Point, VA, United States, (3)Bigelow Lab for Ocean Sciences, East Boothbay, ME, United States
The Extent of N2-Fixation: From the Ice Edge to the Equator in the South Pacific Ocean. (303454)
Raes Raes1, Levente Bodrossy2, Jodie van de Kamp2 and Anya M Waite3, (1)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Bremerhaven, Bremerhaven, Germany, (2)CSIRO, Oceans and Atmosphere, Hobart, TAS, Australia, (3)Ocean Frontier Institute, Dalhousie University, Halifax, NS, Canada
PRIMARY PRODUCTIVITY AND DINITROGEN FIXATION ON THE NORTH ATLANTIC CONTINENTAL SHELF (325459)
Margaret R Mullholland1, Peter W Bernhardt1, Kimberly Hyde2, Antonio Mannino3, Brittany Widner4, Phoebe Dreux Chappell5 and Corday R. Selden6, (1)Old Dominion University, Ocean and Earth Sciences, Norfolk, United States, (2)NOAA Northeast Fisheries Science Center, Narragansett, United States, (3)NASA Goddard Space Flight Center, Ocean Ecology Laboratory, Greenbelt, United States, (4)Woods Hole Oceanographic Institution, MA, United States, (5)University of South Florida, College of Marine Science, St. Petersberg, United States, (6)Rutgers University New Brunswick, Department of Marine and Coastal Sciences, New Brunswick, United States
Reconsidering Coastal Diazotrophy in the North Atlantic: High Rates of N2 Fixation Along the U.S. Southeastern Seaboard (309303)
Corday R. Selden1, Phoebe Dreux Chappell2, Brittany Widner3, Alfonso Macías Tapia4, Peter W Bernhardt1 and Margaret R Mullholland1, (1)Old Dominion University, Ocean, Earth and Atmospheric Sciences, Norfolk, United States, (2)University of South Florida, College of Marine Science, St. Petersberg, United States, (3)Woods Hole Oceanographic Institution, MA, United States, (4)Old Dominion University, Ocean, Earth and Sciences, Norfolk, United States
Contrasting Distribution of N2 Fixation From the Oligotrophic to the Coastal Ocean in the Western North Atlantic Ocean (311735)
Weiyi Tang1, Nicolas Cassar1,2, Seaver Wang1, Debany Fonseca Batista3, Frank Dehairs3, Scott Michael Gifford4, Aridane G. González5 and Hélène Planquette5, (1)Duke University, Earth and Ocean Sciences, Nicholas School of the Environment, Durham, NC, United States, (2)Duke University, Division of Earth and Climate Sciences, Nicholas School of the Environment, Durham, NC, United States, (3)Vrije Universiteit Brussel, Analytical, Environmental and Geo-Chemistry, Ixelles, Belgium, (4)University of North Carolina at Chapel Hill, Earth, Marine and Environmental Sciences, Chapel Hill, United States, (5)IUEM Institut Universitaire Européen de la Mer, LEMAR, Plouzané, France
Global Estimates of Marine Nitrogen Fixation Based on a Non-Redfield Inverse Model (325001)
Francois Primeau1, Weilei Wang2, Adam Martiny1 and J. Keith Moore2, (1)University of California Irvine, Earth System Science, Irvine, CA, United States, (2)University of California, Irvine, Earth System Science, Irvine, CA, United States

See more of: Biogeochemistry and Nutrients