Walker O. Smith, Jr.

Professor of Marine Science

Email: [[wos]]
Phone: (804) 684-7709
Office: Maury Hall 201
Website: {{http://www.vims.edu/bio/phytoplankton/}}
Department: Biological Sciences

Education

• B.S., University of Rochester, Rochester, NY
• Ph.D., Duke University

Research Interests

Our laboratory interests center on the controls of phytoplankton growth and the factors which control the fate of the photosynthetic material in the surface layer of the ocean. To that end we are interested in the interactions between various pools of organic carbon in the surface of the ocean, including dissolved organic carbon, dissolved inorganic carbon, total particulate organic carbon, and living matter (bacteria, micro- and mesozooplankton). We have primarily focused on processes occurring in the Ross Sea, Antarctica, largely because the Antarctic is known to be critical in controlling the marine carbon cycle due to its interaction with the atmosphere and its role in producing deep water. We quantify the contribution of phytoplankton to the particulate organic carbon pool using a number of procedures, and then analyze the fluxes to and from this pool. I have a strong interest on the role of phytoplankton assemblage structure on the vertical flux of material from the ocean's surface, and also have a strong interest in the role of iron in structuring the ocean's phytoplankton productivity and growth. Two projects are presently funded to investigate growth and controls in the Ross Sea: IVARS and CORSACS.

Current Projects

• Interannual Variability in the Antarctic-Ross Sea (IVARS): Nutrients and Seasonal Production (OPP/NSF)
• Quantification and modeling of DOC and DON release in marine systems: a study of increasing trophic complexity (OCE/NSF)
• Seasonal Biogeochemical Processes in the Ross Sea: A Modeling Approach (OPP/NSF)
• Interactive effects of iron, light and CO2 on phytoplankton community dynamics in the Ross Sea (OPP/NSF)
• Environmental and Ecological Regulation of Differences and interactions between Solitary and Colonial forms of Phaeocystis antarctica (pending, OPP/NSF)
• U.S. SO GLOBEC Synthesis and Modeling: Circulation and Hydrographic Data Analyses and Modeling Studies (pending, OPP/NSF)

Selected Publications

• Smith, W.O., Jr. and D.M. Nelson. 1985. Phytoplankton bloom produced by a receding ice edge in the Ross Sea: Spatial coherence with the density field. Science 227: 163 166.
• Smith, W.O., Jr. Editor. 1990. Polar Oceanography. Parts A and B. Academic Press, San Diego. 760 p.
• Smith, W.O., Jr., L.A. Codispoti, D.M. Nelson, T. Manley, E.J. Buskey, H.J. Niebauer and G.F. Cota. 1991. Importance of Phaeocystis blooms in the high latitude ocean carbon cycle. Nature 352: 514 516.
• Cota, G.F., W.O. Smith, Jr. and B.G. Mitchell. 1994. Photosynthesis of Phaeocystis in the Greenland Sea. Limnol. Oceanogr. 39: 948-953.
• Smith, W.O., Jr. and L.I. Gordon. 1997. Hyperproductivity of the Ross Sea (Antarctica) polynya during austral spring. Geophys. Res. Letters 24: 233-236.
• Smith, W.O., Jr., C.A. Carlson, H.W. Ducklow, and D.A. Hansell. 1998. Growth dynamics of Phaeocystis antarctica-dominated plankton assemblages from the Ross Sea. Mar. Ecol. Prog. Ser. 168: 229-244.
• Smith, W.O., Jr., J. Marra, M.R. Hiscock and R.T. Barber. 2000. The seasonal cycle of phytoplankton biomass and primary productivity in the Ross Sea, Antarctica. Deep-Sea Res. II 47: 3119-3140.
• Smith, W.O., Jr. and V.A. Asper. 2000. A balanced nitrogen budget of the surface layer of the Southern Ross Sea, Antarctica. Geophysical Research Letters 27: 2721-2724.
• Smith, W.O., Jr. and V.A. Asper. 2001. The influence of phytoplankton assemblage composition on biogeochemical characteristics and cycles in the southern Ross Sea, Antarctica. Deep-Sea Res. I 48: 137-161.
• Smith, W.O., Jr. and C.M. van Hilst. 2003. Effects of assemblage composition on the temporal dynamics of carbon and nitrogen uptake in the Ross Sea. In: Biogeochemical Cycles in the Ross Sea (G.R. DiTullio and R.B. Dunbar, editors), Antarctic Res. Ser., American Geophysical Union, pp. 197-208.
• Smith, W.O., Jr., M.R. Dennett, S. Mathot and D.A. Caron. 2003. The temporal dynamics of the flagellated and colonial stages of Phaeocystis antarctica in the Ross Sea. Deep-Sea Res. II 50: 605-618.
• Smith, W.O., Jr., M.S. Dinniman, J.M. Klinck, and E. Hoffman. 2003. Biogeochemical climatologies in the Ross Sea, Antarctica: seasonal patterns of nutrients and biomass. Deep-Sea Res. II 50: 3083-3101.
• Oliver, J.E., R.T. Barber, W.O. Smith, Jr., and H.W. Ducklow. The heterotrophic bacterial response during the Southern Ocean Iron Experiment (SOFeX). Limnol. Oceanogr. 49: 2129-2140.
• W.O. Smith, Jr. and D.G. Barber (Eds.), Polynyas: Windows to the World's Oceans Elsevier, Amsterdam (submitted).
• Hiscock, M.R., V.P. Lance, A. Apprill, R.R. Bidigare, B.G. Mitchell, W.O. Smith Jr., and R.T. Barber. Southern Ocean iron response is quantum yield driven. Science (submitted).
• Smith, W.O., Jr. G. Catalano, A.R. Shields, J.A. Peloquin, S. Tozzi, M. Dinniman and V. Asper. Biogeochemical budgets in the Ross Sea: variations among years. Deep-Sea Res. II (submitted).

Current Students

• Sasha Tozzi, Ph.D. Student
• Amy Shields, Ph.D. Student

Past Students

• Jill Peloquin, Ph.D. Student
• Liza Delizo, M.S. awarded 2003
• Christina van Hilst, M.S. awarded 2000

Courses Taught

• MS 501:  Fundamentals of Marine Science 
• MS 659:  Phytoplankton Ecology
• MS 698:  Polar Oceanography

Collaborative/Interdisciplinary Efforts

• IVARS (Interannual Variations in the Ross Sea), with Dr. Vernon Asper (University of Southern Mississippi)
• Seasonal Biogeochemical Processes in the Ross Sea: A Modeling Approach (with Eileen Hofmann and John Klinck, Old Dominion University)
• CORSACS (Interactive effects of iron, light and CO2 on phytoplankton community dynamics in the Ross Sea), with Drs. Giacomo DiTullio (Inversity of Charleston), Peter Sedwick (Bermuda Biological Station), Dave Hutchins (University of Deleware), Phillippe Tortell (University of British Columbia) and Rob Dunbar (Stanford University)