35. COMPARISONS OF DIATOM BIOCOENOSES WITH HOLOCENE SEDIMENT ASSEMBLAGES IN PRYDZ BAY, ANTARCTICA1

• Main Authors: Dean A. Stockwell, Sung-ho Kang, Greta A. Fryxell
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: East Antarctica; Prydz Bay; Antarc*; Antarctica
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.552.3308; http://www-odp.tamu.edu/publications/119_SR/VOLUME/CHAPTERS/sr119_35.pdf

Quantitative and qualitative examinations of the planktonic diatom population of Prydz Bay, East Antarctica, were conducted during Ocean Drilling Program Leg 119. Water column production was intense, as evidenced by high concen-trations of chlorophyll a (ranging from 40.0 to 576.5 mg Chi a m~2) and by high diatom abundances (ranging from 3.76 × 1010 to 2.9 × 1011 cells m~2). Water column biomass was primarily dominated by three ice-related pennates: Nitz-schia closterium, N. cylindrus, and N. curta. Together, these three diatoms accounted for 64%-96 % of the water col-umn assemblage. Sediment diatom assemblages mirrored this intense water column production, with valve numbers ranging from 3.4 × 107 to 6.8 × 109 valves g~l sediment. The genus Nitzschia typically formed 70 % of the diatom thanatocoenose. N. curta and N. cylindrus together accounted for 34.6%-78.3 % of the total assemblage. The heavily silicified resting spores of Chaetoceros were also an important component of these sediments (accounting for 8%-34 % of the total as-semblage).