The relation between phytoplankton standing stock and water temperature in the Antarctic Ocean in summer, 1980-1981

• Main Author: Shiroh Uno
• Format: Report
• Language: English
• Published: Far Seas Fisheries Research Laboratory 1983
• Subjects: Antarctic; Antarctic Ocean; The Antarctic; Antarc*; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1432; http://id.nii.ac.jp/1291/00001432/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1432&item_no=1&attribute_id=18&file_no=1

The vertical distribution of chlorophyll α in the Antarctic Ocean was observed by R. V. KAIYO MARU during the FIBEX cruise from December 1980 to January 1981. Two different distribution patterns of chlorophyll α were found during this period. In December the chlorophyll α maximum at most of stations was found in the upper layer above 50m in Area B, and it coincided with the pycnocline. While in January, the maximum was found in a deeper layer below 75m in Area A, and it did not coincide with the pycnocline where the particulate matter was concentrated. It was presumed that the deep chlorophyll α maximum in January was not caused by physical accumulation of suspended matter or by factors internal to phytoplankton cells, but depended on the structure of water temperature. The locations of the chlorophyll α maximum layers showed good agreement with water temperature within the range of -1.4℃ to -0.3℃ in both December and January. In December, the water temperatures from the surface to 50m were within this range. On the other hand, in January the water temperature in the upper layers rose to above 0℃, and phytoplankton biomass would be limited in these layers, whereas maximal biomass occurred in the deeper layers between 50m and 125m depth. The relation between chlorophyll α and water temperature was re-examined using the results from icebreaker FUJI and R. V. KAIYO MARU, which showed trends similar to those of the present study.