Phytoplakton and Zooplankton Standing Stocks and Downward Flux of Particulate Material around Fast Ice Edge of Lutzow-Holm Bay,Antarctica

Phyto- and zooplankton standing stocks in the fast ice and in the water column under the ice and downward flux of particulate material through the water column were investigated in Liitzow-Holm Bay, Antarctica, during the austral summers, i.e., in January 1977 and February 1979. Chlorophyll a standing stock integrated through the ice was 0.38-0.80 mg/m^2 and that in the water column beneath the ice down to 150 m was 3.06 mg/m^2. Microdistribution of zooplankton beneath the ice was observed by the pumping collections and the dense populations were found just beneath the ice. Zooplankton density was in a range of 12-60 indiv/m^3 and the zooplankton stocks integrated through the 150 m water column ranged from 6000 to 7675 indiv/m^2. By the sediment trap operation, the fecal materials were found to comprise a large proportion of the collected particles. The maximum daily vertical flux of particulate organic carbon (POC) was found at the 100m depth (103 mg C/m^2/day) and concentration of POC in the water column was in a range of 24-56 mg C/m^3. These data on standing stocks of phyto- and zooplankton and vertical flux of POC in the icecovered Liitzow-Holm Bay were compared with those in the other sea areas

A Preliminary Note on the Occurrence of Copepods under Sea Ice near Syowa Station,Antarctica

Net samplings of zooplankton were done in the ice-covered sea area near Syowa Station (69°00\u27S, 39°35\u27E), Antarctica, during the summer, autumn and spring seasons in 1970 and 1975. Copepods were the main constituents of the zooplankton community. Ctenocalanus vanus, Stephus longipes, Paralabidocera antarctica, Oithona similis, Oithonafrigida, Oncaea curvata and Harpacticoid copepods were identified. Among them, while unidentified copepod nauplii were numerously distributed, O. similis and O. curvata occurred dominantly during late summer, autumn and spring. P. antarctica and O.frigida occurred in small numbers in summer. Species composition of copepods changed seasonally

Xth SCAR International Biology Symposium on “Antarctic Biology in the 21st Century—Advances in and beyond IPY—”: A brief overview

AbstractThe Xth SCAR International Biology Symposium was held under the theme of “Antarctic Biology in the 21st Century—Advances in and beyond IPY—“ at the Conference Hall, Hokkaido University, between July 26 and 31, 2009. A total of 113 oral presentations and 122 poster presentations were given under six sub-themes. This special issue was edited by six guest editors under the Editor-in-Chief of “Polar Science”, in accordance with the editorial system of “Polar Science” and contains one overview paper and five review papers and 18 research papers

A simple method for estimating phytoplankton abundance using a surface seawater monitoring system off Syowa Station during austral summer

A surface seawater monitoring system was used aboard the Shirase to estimate phytoplankton abundance while the icebreaker was anchored in an ice covered area off Syowa Station during the austral summer of 1996/97. A significant positive relationship was observed between the digital output (OP) values of the chlorophyll fluorometer of the system, and chlorophyll a (Chl a) concentrations of the seawater that passed through the system. Using this relationship, OP values were converted into Chl a (Chl a OP). Throughout the present study, the Chl a OP was found to be consistent with temporal changes in Chl a observed in the field near the Shirase, with high Chl a OP values measured in relatively warm and less saline water. These findings suggest that the high Chl a may be derived from the ice-edge phytoplankton blooms that develop in stable waters associated with melting ice. Relatively simple operation without need for complicated maintenance procedures facilitates the ease with which the system can be used. The operation of the system every summer may facilitate the acquisition of data that reveal the long-term variability of phytoplankton biomass under fast ice

Vertical distribution of size fractionated phytoplankton chlorophyll in the Indian sector of the Southern Ocean in summer(1985/86)

During the icebreaker SHIRASE cruise of the 27th Japanese Antarctic Research Expedition (JARE-27; 1985/86), vertical profiles of phytoplankton chlorophyll a concentration in the upper 200m of the water column were observed at 12 stations in the Southern Ocean and at 3 stations in the subtropical water from December 1985 to March 1986. High phytoplankton chlorophyll standing crops (ca. 370mg m^ in December and 330mg m^ in February) were observed in Breid Bay, Antarctica. In other stations of the Antarctic Ocean, the standing crops were less than 52mg m^. Size fractionation studies revealed that net-phytoplankton (>20μm) was the dominant fraction of total chlorophyll a during the summer bloom in Breid Bay. In Antarctic waters, the high contributions of the net-phytoplankton fraction corresponded to high total biomass. And also, contribution of the net-phytoplankton to the total phytoplankton was supposed to be controlled by the length of the ice-free period. Considering the high phytoplankton growth rates under the nutrient rich condition, duration under optimum light condition and water stability appear to be important factors affecting the phytoplankton crops in the Antarctic Ocean in summer