| Budget Amount *help |
¥6,900,000 (Direct Cost: ¥6,900,000)
Fiscal Year 1995: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1994: ¥5,700,000 (Direct Cost: ¥5,700,000)
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| Research Abstract |
^<13>C tracer experiments were carried out in the East China Sea (Aug.1994 and Oct.1996) and North pacific (Nov.1995) during the cruises of R/V "Kaiyo", Japan Marine Science and Technology Center and R/V "Hakuho-maru", Ocean Research Institute, University of Tokyo, respectively. Incubation experiments were continued for 24h and dissolved organic matter was separated from particulate organic constituents by filtration using glass fiber filter (Whatman GF/F). The pressure for the filtration was controlled less than 150mmHg.
Primary productivity varied form 200mgC m^<-2>d^<-1> at subtropical gyre to 1,500mgC m^<-2>d^<-1> at the Changjian estuary. Particulate fatty acid production rate was determined by ^<13>C/GC/MA method. Fatty acids such as 14 : 0,16 : 0 and 16 : 1 were major acids constituting particulate products and the contribution of 16 : 1 showed a spatial variation.
For the determination of ^<13>C atom % of dissolved organic carbon, dissolved organic carbon was firstly converted to carbon dioxide by wet oxidation method. A little increase in the ^<13>C atom % in dissolve organic carbon was found at every station, indicating the production of dissolved organic carbon during the incubation experiments. ^<13>C atom % of dissolved fatty acid estimated and increase in the atom % was noted in some fatty acids at the high productivity stations. At low productivity stations, on the other hand, no fatty acid showed the increase in the ^<13>C atom %, showing little dissolved fatty acid was produced through photosynthesis of phytoplankton.
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