Phytoplankton cell flux under fast ice near Syowa Station, Antarctica, in austral summer 1991/1992

• Main Authors: 小達 恒夫, 佐々木 洋, 福地 光男, Tsuneo Odate, Hiroshi Sasaki, Mitsuo Fukuchi
• Format: Report
• Language: English
• Published: 研究ノート 2004
• Subjects: 59(26); Austral; Syowa Station; Antarc*; Antarctica
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=9285; http://id.nii.ac.jp/1291/00009285/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=9285&item_no=1&attribute_id=18&file_no=1

1992年1月7日から2月6日の期間,南極昭和基地周辺の定着氷下にセジメントトラップを設置し,沈降粒子を採集した.得られた試料を基に顕微鏡観察を行い,植物プランクトン細胞数のフラックス(PN)及び細胞体積から換算した植物プランクトン炭素フラックス(PC)を見積もった.PNフラックスは,1月上旬に低く,1月末から2月初めに最も高く,その時間変動は過去の報告と一致した.しかしながら,その値は過去の報告値に比べ数倍低く,上層の植物プランクトン現存量の年変動に起因するものと考えられた.PCフラックスも,PNフラックスと同じような時間変動を示した.以前に報告したクロロフィルフラックスの値とPCフラックスを比較すると,PC : クロロフィル比は,文献値に比べやや低い約17と見積もられた. Settling particles were collected using sediment traps, which were deployed beneath fast ice near Syowa Station, Antarctica, from January 7 to February 6 1992. Fluxes of phytoplankton cell number (PN) and carbon (PC) were estimated based on microscopic observation and determination of cell volume. During the present study period, PN flux was low in the early half of January and reached a maximum at the end of January or the beginning of February. Although patterns of temporal change of PN flux were consistent with a previous study, the values were several times lower in the present study than in the previous report. Interannual variation of phytoplankton biomass in the surface layer seems to result in differences in phytoplankton flux. The temporal variation of PC flux was similar to that of the PN flux. Comparing PC flux and chlorophyll a (Chl a) flux, which was reported in a previous study, a PC : Chl a ratio of about 17 was estimated. This value is slightly lower than literature PC : Chl a ratios.