SEASONAL VARIATION OF DOWNWARD FLUX OF PARTICULATE ORGANIC MATTER UNDER THE ANTARCTIC FAST ICE (Ninth Symposium on Polar Biology)

• Main Authors: マツダ オサム, イシカワ シンゴ, カワグチ コウイチ, Osamu MATSUDA, Shingo ISHIKAWA, Kouichi KAWAGUCHI
• Format: Report
• Language: English
• Published: Proceeding 1987
• Subjects: Antarctic; East Ongul Island; Kita-no-ura; Ongul; Ongul Island; The Antarctic; Ura; Antarc*; ice algae; Polar Biology; Proceedings of the NIPR Symposium on Polar Biology
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=5012; http://id.nii.ac.jp/1291/00005012/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=5012&item_no=1&attribute_id=18&file_no=1

During the BIOMASS study of the SIBEX (1984/85), seasonal variation of downward flux of particulate organic matter under the Antarctic fast ice was studied throughout the year in the Kita-no-ura Cove (69°00'S, 39°35'E) off East Ongul Island in Lutzow-Holm Bay. Marked seasonal variation of particulate organic carbon (POC) flux was observed; larger fluxes in summer (max: 136 mgC/m^2 day) but smaller fluxes in winter (min: 1.5 mgC/m^2 day). Although both particulate organic nitrogen (PON) and particulate phosphorus (PP) flux showed similar trends to POC variation, C: N: P ratio also varied seasonally. Chlorophyll a flux varied more drastically than POC did (max: 4500 in summer, min: 3 μg/m^2 day in winter), suggesting the direct input of ice algae and/or phytoplankton to the benthic community in summer. Judging from the variation of POC/chl. a ratio, fresh algae dominated from November through February among trapped sediments. While, a small amount of sinking particles mainly composed of deteriorated material was observed in winter. Relative abundance of chl. a and pheopigments differed between sampling depths, which indicated the decomposition of particles during sinking. The seasonal variation of total mass flux generally well reflected those of chlorophyll and POC concentration, hence the seasonal variation of primary production under the fast ice.