OCCURRENCE AND DISTRIBUTION OF THE PLANKTONIC FORAMINIFER NEOGLOBOQUADRINA PACHYDERMA WITHIN ANNUAL AND PERENNIAL SEA ICE OF THE EASTERN PART OF LUTZOW-HOLM BAY, ANTARCTICA (17th Symposium on Polar Biology)

• Main Authors: イガラシ アツオ, ヌマナミ ヒデキ, ツチヤ ヤスタカ, フクチ ミツオ, Atsuo IGARASHI, Hideki NUMANAMI, Yasutaka TSUCHIYA, Mitsuo FUKUCHI
• Format: Report
• Language: English
• Published: Proceeding 1996
• Subjects: Austral; Syowa Station; Antarc*; Antarctica; Neogloboquadrina pachyderma; Polar Biology; Proceedings of the NIPR Symposium on Polar Biology; Sea ice
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=5307; http://id.nii.ac.jp/1291/00005307/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=5307&item_no=1&attribute_id=18&file_no=1

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 Ltitzow-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 foraminifer 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 foraminiferal 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.