HR: 15:00h
AN: OS52H-05    [PDF]
TI: Nutrient Utilization and Nutrient Cycle in the Marguerite Bay region, West Antarctic Peninsula
AU: * Serebrennikova, Y
EM: yulias@seas.marine.usf.edu
AF: College of Marine Science, University of South Florida, 140 7th Avenue South, St. Petersburg, FL 33701 United States
AU: Fanning, K A
EM: kaf@seas.marine.usf.edu
AF: College of Marine Science, University of South Florida, 140 7th Avenue South, St. Petersburg, FL 33701 United States
AB: Estimates of the autumnal deficit of nutrients (total inorganic nitrogen, phosphate, and silicate) and nutrient utilization ratios have been made for Marguerite Bay and the adjacent portion of the continental shelf west of the Antarctic Peninsula from data collected in April-May, 2001. The estimates were calculated from the depth-integrated depletion of nutrients in the autumnal surface layers down to the depths of the temperature minimum that represented the remnants of the Winter Water produced during the previous winter. The observed low N: P utilization ratios of 11.6 $\pm$ 0.4 mol:mol and high Si: N utilization ratios of 4 $\pm$ 1 mol:mol suggest that diatoms dominate in the nutrient utilization in the region. The deficit of carbon, estimated using a C: N ratio of 7:1 mol:mol, ranged from 0.8 mol C/m2, typical for the most of the low productive Southern Ocean, to 9.4 mol C/m$^{2}$, similar to that found in the productive areas of the Ross Sea. The largest deficit of nutrients and carbon was found in Marguerite Bay and along the coast to north and south of the bay. The low deficit values occurred beyond the shelf break at locations within the Antarctic Circumpolar Current (ACC) and extended onto the shelf at sites of ACC on-shelf intrusions. The seasonal evolution of nutrients through the following winter to early spring has been investigated. The nutrient concentrations in the surface layer increased from April-May to July-August and reached the previous winter values in September-October. The 2001 autumnal nutrient findings were compared to those of the autumn 2002.
DE: 4207 Arctic and Antarctic oceanography
DE: 4815 Ecosystems, structure and dynamics
DE: 4845 Nutrients and nutrient cycling
SC: Ocean Sciences [OS]
MN: 2004 Ocean Sciences Meeting