Mitsuo Fukuchi

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The seasonal variations of limnological (water temperature, light availability, turbidity, and chlorophyll a concentration) parameters were recorded continuously from January 2004 to February 2005 at two freshwater lakes: Oyako-ike and Hotoke-ike, Sôya Coast, East Antarctica. Water was in a liquid phase throughout the year, with temperatures ranging from 0(More)
Antarctic and Southern Ocean (ASO) marine ecosystems have been changing for at least the last 30 years, including in response to increasing ocean temperatures and changes in the extent and seasonality of sea ice; the magnitude and direction of these changes differ between regions around Antarctica that could see populations of the same species changing(More)
Light environment, community structure, pigments, and photophysiological properties of mat-forming phytobenthos were studied in four shallow Antarctic lakes in 2007 at maximum water depths of 1.7–2.5 m. All lakes were oligotrophic, and water transparencies were high, enabling 45–60% of photosynthetically active radiation (PAR, 400–700 nm) and 20–40% of(More)
A sediment trap deployment was made at a station (64°42′S, 139°59′E) at five depths (537, 796, 1,259, 1,722, 2,727 m) in the marginal ice zone (MIZ) of the Antarctic Ocean during a summer productive period from 26 December 1994 to 20 January 1995. This aim of the study was to reveal a possible occurrence of a sporadic bloom in surface layers and to evaluate(More)
Regional variability in the annual fluxes of particulate organic carbon (POC) and biogenic silica (Si) at the periphery of the Mackenzie Shelf (Beaufort Sea) was investigated using eight long-term sediment traps moored at ~100-m depth. Relatively high autochthonous POC and Si fluxes were recorded in the Mackenzie Trough (4.1 and 8.9 g m−2 year−1(More)
The diel vertical distributions of two small copepods, Oithona similis and Oncaea curvata, were investigated at 4-h intervals over a 24-h period under fast ice near Syowa Station during continuous daylight conditions in the Antarctic mid-summer, December 1993. Oithona similis and O. curvata exhibited small-scale diel vertical migrations during the study(More)
Photosynthetic oxygen production by phytoplankton and community respiration in the Indian sector of the Antarctic Ocean were estimated from changes in oxygen concentrations in light and dark bottles. Gross production varied between 0.1 and 5.1 µmol O2 l– 1 day– 1. In the same water, community respiration (the sum of oxygen consumption by heterotrophs and(More)
Temporal variations in the microbial community structure of plankton, which is composed of autotrophic and heterotrophic pico-, nano- and microplankton, were investigated during the austral summer of 2005/2006 under fast ice near Syowa Station, eastern Antarctica. Autotrophic algal populations were composed almost entirely of diatoms followed by(More)
Time-series sediment traps were deployed at six mooring sites in the southeastern Beaufort Sea from October 2003 to August 2004 during the cruise of the Canadian research vessel Amundsen within the framework of the Canadian Arctic Shelf Exchange Study (CASES). Trap-collected zooplankton (TCZ) at around 200 m water depth was dominated by copepods accounting(More)
The occurrence and age structure of an Antarctic ice-associated copepod, Paralabidocera antarctica, were investigated using a light trap under fast ice near Syowa Station. Sampling was carried out between May and November 1984. P. antarctica were found in high numbers in the traps on 1–2 and 23–24 November. No copepods were found in any trap between May and(More)