Kevin R. Arrigo,
*
Dale H. Robinson,
Denise
L. Worthen,
Robert B. Dunbar,
Giacomo R. DiTullio,
Michael VanWoert,
Michael P. Lizotte
Data from recent oceanographic cruises show that phytoplankton
community structure in the Ross Sea is related to mixed layer depth.
Diatoms dominate in highly stratified waters, whereas Phaeocystis antarctica assemblages dominate where waters are more deeply
mixed. The drawdown of both carbon dioxide (CO2) and
nitrate per mole of phosphate and the rate of new production by diatoms
are much lower than that measured for P. antarctica.
Consequently, the capacity of the biological community to draw down
atmospheric CO2 and transport it to the deep ocean could
diminish dramatically if predicted increases in upper ocean
stratification due to climate warming should occur.
K. R. Arrigo, NASA Goddard Space Flight Center, Code 971.0, Greenbelt, MD 20771, USA. D. H. Robinson. Romberg Tiburon
Center for Environmental Studies, San Francisco State University, 3150 Paradise Drive, Post Office Box 855, Tiburon, CA 94920-0855, USA.
D. L. Worthen, Science Systems and Applications, Lanham, MD 20706, USA. R. B. Dunbar, Geological and Environmental Sciences,
Stanford University, Stanford, CA 94305-2115, USA. G. R. DiTullio, University of Charleston, Grice Marine Laboratory, 205 Fort
Johnson, Charleston, SC 29412, USA. M. VanWoert, National Oceanic
and Atmospheric Administration, NESDIS, E/RA3 World Weather Building,
4700 Silver Hill Road, Washington, DC 20233-9910, USA. M. P. Lizotte, Department of Biology and Microbiology, University of
Wisconsin Oshkosh, Oshkosh, WI 54901, USA.
*
To whom correspondence should be addressed.
