Project Description and Who's Who

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R/V Nathaniel B. Palmer

Jack DiTullio (Chief Scientist), Associate Professor, Biological and Chemical Oceanography, College of Charleston

David Hutchins, Professor of Oceanography, University of Delaware Graduate College of Marine Studies

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Peter Sedwick, Associate Reseach Scientist, Bermuda Insitute of Oceano Sciences (formerly BBSR)

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Rob Dunbar, Professor of Geological and Environmental Sciences, Stanford University

Walker Smith, Professor, Department of Biological Sciences, Virgina Institute of MArine Sciences

Philippe Tortell,Assistant professor Botany/Oceanography, University of British Columbia, Canada

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Mak Saito, Assistant Scientist Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution

Project summary

Our main objective in this proposed research is to investigate the relative importance and potential interactive effects of iron, light and CO2 levels in structuring algal assemblages and growth rates in the Ross Sea.  We hypothesize that the interaction of these three variables largely determines the bottom-up control on these two dominant Southern Ocean phytoplankton taxa. Grazing and other loss processes will also be important variables in determining the relative dominance of these two taxa; however, the study proposed here will primarily focus on the bottom-up control mechanisms. It is important to understand such environmentally-driven taxonomic shifts in primary production, since they are expected to impact the fixation and export of carbon and nutrients, and the production of DMS, thus potentially providing both positive and negative feedbacks on climate.

Within the context of this proposal, we consider a range of ambient iron, light and pCO2 levels that span those typically observed in the Ross Sea during the growing season.  That is, dissolved iron ranging from ~0.1 nM (“low iron”) to >1 nM (“high iron”) (Fitzwater et al. 2000; Sedwick et al. 2000); mean irradiance (resulting from vertical mixing/self shading) ranging from <10% Io (“low light”) to >40% (“high light”) (Arrigo et al., 1998, 1999), which may be adjusted based on our field observations (see section 6.3.3); and pCO2 ranging (Sweeney et al. 2001) from ~150 ppm (“low CO2”) to the probable higher levels of pCO2 — 750 ppm as a conservative estimate — that are likely to be attained later this century due to anthropogenic perturbation of the global carbon cycle (IPCC, 2001).

From the information currently available from both field observations and experiments, we have formulated the following specific hypotheses regarding the interactive role of iron, light and CO2 in regulating algal composition in the Ross Sea.  Principally, we propose that diatoms bloom in the southern Ross Sea only under optimum conditions of high iron, light and pCO2; colonial Phaeocystis dominate under conditions of high iron with either (or both) low light or low pCO2; and solitary Phaeocystis are predominant under conditions of low iron with either (or both) low light or low pCO2.  Two cruises are planned to investigate the interactions between the primary productivity of the Ross Sea and pCO2, iron and other trace elements.

Additional Information on Cobalt Cadmium and Zinc and Ferric Reductase studies on this cruise (Saito Laboratory)

Science Party 2006

Jack DiTullio - CORSACS Chief Scientist , University of Charleston
Ana Aguilar-Islas - Grad student, UCSC
Thomas Baird
Erin Bertrand - Grad student, WHOI
Giulio Catalano
Rob Dunbar - P.I., Stanford University
Yuanyuan Feng - Grad student
Jay Francella - Grad student
Nathan Garcia
Tyler Goepfert - Research Assistant, WHOI
Clint Hare - Grad student
Dave Hutchins, PI, University of Delaware
Lindsey Kropuenske
Peter Lee - Post-doc
Yingyu Li
Maeve Lohan - Senior Lecturer, U Plymouth, UK
Matt Long - Ph.D. student, Stanford University
Christopher Marsay - Research Associate, BIOS (formerly BBSR)
Juliana Miller
Angela Milne
Dave Mucciarone - Lab Manager, Stanford University
Aimee Neeley - Research Assistant
Christopher Payne - Grad student
Scott Polk
Okori Puryear
Quinn Roberts
Julie Rose - Postdoc
Mak Saito - PI, WHOI
Pete Sedwick - PI, BIOS (formerly BBSR)
Walker Smith - PI, Virginia Institute of Marine Science
Sasha Tozzi - Grad student
Scarlett Trimborn

Science Party 2005

Jack DiTullio - CORSACS Chief Scientist , University of Charleston
Peter Lee, Post-doc
David Jones, Research Associate
Aimee Neeley, Research Assistant
Jay Francella, Grad student
Brian Taylor, Research Assistant
Rob Dunbar, P.I., Stanford University
Dave Mucciarone, Lab Manager, Stanford University
Eduard Costa, Post-doctoral fellow, Stanford University
Matt Long, Ph.D. student, Stanford University
Christina Riesselman, Ph.D. student, Stanford University
Dave Hutchins (PI),
Clint Hare (grad student),
Yuanyuan Feng (grad student),
Sara Handy (grad student),
Julie Rose (postdoc)
Mak Saito (PI),
Abigail Noble (Research Assistant),
Tyler Goepfert (Research Assistant),
Erin Bertrand (Research Assistant).
Peter Sedwick (PI, BBSR)
Chris Marsay (research associate, BBSR)
Maeve Lohan (Senior Lecturer, U Plymouth, UK)
Ana Aguilar-Islas (grad student, UCSC)
Juliette Tria (grad student, U Tasmania)
Walker Smith, PI Virginia Institute of Marine Science
Jill Peloquin, Post-doc
Sasha Tozzi (grad student)
Carol Pollard (grad student)
Jennifer Dreyer (grad student)
Phillipe Tortel (PI) University of British Columbia
Celine Gueguen (postdoc)
Chris Payne (grad student)

Related Links

Ocean Literacy Education Sites
Classroom Ideas for Studying Ocean Life by National Geographic
The Bridge - a marine education website
A General Overview of the Iron Hypothesis (focused on the Soiree Cruise)

General Sites
The US Antarctica Program Web Portal
The US Antarctica Program Photo of the Week
The National Science Foundation Office of Polar Programs
The Diatom Genome sequencing project (Thalassiosira pseudonana)
Virtual Tour of McMurdo Station
NSF website on McMurdo Station
The IVARS Research Program (Interannual Variability in the Ross Sea)
Updates/Blogs/Information from the Previous Leg of the Research Vessel N.B. Palmer

Chemistry and Marine Chemistry Sites
The Periodic Table of Elements In the Ocean
Another Periodic Table of Elements in the Ocean - with more info by Ken Johnson
Online Periodic Table: Webelements

Participating Scientists Websites
Jack DiTullio's Biological and Chemical Oceanography Laboratory at University of Charleston, SC
Dave Hutchins' Laboratory at University of Delaware, College of Marine Studies
Walker Smith's Plankton Ecology group, Virginia Institute of Marine Science
Philippe Tortell's Marine Ecology and Biogeochemistry Laboratory at University of British Columbia
Rob Dunbar's website, School of Earth Sciences Stanford University
Pete Sedwick's faculty profile Bermuda Biological Station for Research
Mak Saito's Trace Metal Biogeochemistry Laboratory at the Woods Hole Oceanographic Institution
Maeve Lohan, Lecturer University of Plymouth UK
Ana Aguilar-Islas, Graduate Student at University of California Santa Cruz


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Last updated November 4, 2006
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