Budget Amount *help |
¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000)
Fiscal Year 2013: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2012: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2011: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
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Outline of Final Research Achievements |
Regular monitoring of estuarine and coastal areas at fixed points was carried out to investigate changes in biomass and species composition of thraustochytrids, which are colorless heterotrophs in the class Labyrinthulomycetes, Stramenopiles. Cell number counts showed that 1 or 2 conspicuous peaks in abundance (termed ‘thraustochytrid spikes’) occurred between spring and late summer in most sampling years. Although thraustochytrid biomass was only 1.59% that of bacterial biomass, the fixed energy (as biomass) transferred directly from thraustochytrids to zooplankton was estimated to be 15.9% of that transferred from bacterioplankton via phagotrophic protists. A similar seasonal succession of phylogenetic groups was observed in each year of sampling. The differences in thraustochytrids isolated at each monitoring site and date suggest that habitat segregation may occur as a result of differences in environmental factors such as water temperature, salinity, and nutrient sources.
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