Phytoplankton community structure and the drawdown of nutrients and CO2 in the Southern Ocean

• Published in: Science (American Association for the Advancement of Science) Vol. 283; no. 5400; pp. 365 - 367
• Main Authors: ARRIGO, K. R, ROBINSON, D. H, WORTHEN, D. L, DUNBAR, R. B, DITULLIO, G. R, VANWOERT, M, LIZOTTE, M. P
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 15.01.1999; The American Association for the Advancement of Science
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Carbon dioxide; Community Relations; Fundamental and applied biological sciences. Psychology; Global warming; Oceanography; Oceans; Phaeocystis antarctica; Plankton; Sea water ecosystems; Synecology; Water; Ross Sea; Southern Ocean; PS, Antarctica; PS, Antarctic Ocean; PS, Ross Sea; Availability; Phosphates; Warming; Algae; Vertical distribution; Carbon dioxide; Population structure; Nitrates; Haptophyta; Marine environment; Heterokontophyta; Mixed layer; Bacillariophyta; Air sea interface; Horizontal distribution; Nutrient; Phytoplankton; Climate modification; Thallophyta
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.283.5400.365

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.