Oceanography in Japan
Online ISSN : 2186-3105
Print ISSN : 0916-8362
ISSN-L : 0916-8362
Volume 18, Issue 5
Displaying 1-1 of 1 articles from this issue
Original Paper
  • Jonaotaro Onodera, Kozo Takahashi, Hiroji Onishi, Mitsuru Yanada
    Article type: research-article
    2009 Volume 18 Issue 5 Pages 307-322
    Published: September 05, 2009
    Released on J-STAGE: March 27, 2023
    JOURNAL FREE ACCESS

    In order to decipher the relationship between the changes in diatom floral fluxes and the oceanographic condition, we've deployed sediment traps at Stations AB (the Aleutian Basin) and SA (the central subarctic Pacific) from August of 1990 to the present. For the first eight years, we've conducted a diatom flux study. Total diatom fluxes (TDF) at both stations usually showed spring and/or fall peaks in a year. However, significant interannual variations of TDF were observed at both stations. At Station SA, significant correlation coefficient was obtained between mean TDF of each year and Pacific Decadal Oscillation index. These interannual variations are possibly due to the differences in the strength and timing of winter mixing and the subsequent summer stratification. The dominant species at both stations was Neodenticula seminae with mean abundances of 80% (Station AB) and 82% (Station SA) of TDF throughout the sampled duration. Coastal species were more abundant at Station AB than Station SA. At Station SA, relatively small numbers of Chaetoceros resting spores occurred in summers of some years as the result of lateral advection from the Aleutian Islands. During the eight years, the slight changes of diatom sinking flora were observed at both stations. Whether or not these trends suggest the changes in oceanographic condition for long-term, a further observation is warranted and to be continued.

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