Japan Marine Science and Technology Center, 2-15 Natsushima, Yokosuka, Kanagawa, 237-0061, Japan, Tel: 81-468-67-9502, Fax: 81-468-67-9455, E-mail: hondam@jamstec.go.jp
Oceanic biological activity plays an important role in the control of atmospheric CO2. Since the early 1990’s, Japan Marine Science and Technology Center (JAMSTEC) has participated or conducted time-series sediment trap experiments in the marginal sea (Okhotsk Sea, Bering Sea, Okinawa Trough) and pelagic ocean in the northwestern North Pacific. Based on results of these experiments and other sediment trap experiments in the global ocean, it was confirmed that diatom species are pre-dominant, and the organic carbon flux and ratio of organic carbon to inorganic carbon flux (rain ratio) is high. Moreover, Japanese time-series observation at station KNOT and recent observation in the NWNP demonstrate that the export flux and ratio are higher than those at other time-series stations (ALOHA, BATS, OSP). Although annual primary productivity is not always high and vertical change in organic carbon flux is large, biological pump in NWNP works more efficiently for the uptake of atmospheric CO2 than other oceans. This is supported by recent surface pCO2 analysis.