OCCURRENCE AND DISTRIBUTION OF THE PLANKTONIC FORAMINIFER NEOGLOBOQUADRINA PACHYDERMA WITHIN ANNUAL AND PERENNIAL SEA ICE O F THE EASTERN PART OF

• Main Authors: Atsuo Igarashi, Hideki Numanam, Yasutaka Tsuchiya, Mitsuo Fukuchi
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Austral; Syowa Station; Neogloboquadrina pachyderma; Sea ice
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.537.8705; http://polaris.nipr.ac.jp/~penguin/polarbiosci/issues/pdf/1996-Igarashi.pdf

Abstract: Annual and perennial sea ice cores, collected regularly for a period of one year at four fixed stations and one time each at 10 other stations in the eastern part of Lutzow-Holm Bay, were investigated to elucidate characteristics of vertical distribution and abundance of planktonic foraminifers within sea ice. At Station A-5, situated about 3 km east of Syowa Station, the planktonic foramin-ifer Neogloboquadrina pachyderma with cytoplasm is present mainly within sections between 20 and 40 cm from the top of the cores. At Station A-2, located near Syowa Station, they are restricted predominantly to the lowermost 50 cm sections of the cores. At Station D, located about 20 km west of Syowa Station, they are distributed maximally within sections between 210 and 244 cm from the top of the cores. Considering the vertical distribution of foraminifers within sea ice and the time of freezing of sea ice, the main time of foraminifera1 incorporation is estimated to be from mid-April to mid-May, that is, from austral late autumn to early winter. The foraminifers may probably become congregated in the uppermost part of the water column in order to feed on abundant diatoms during spring and summer. Until the onset of ice formation from late April to mid-May, they may still remain there and are likely to be accidentally incorporated into the sea ice. 1.