TERRAPUB Journal of Oceanography

Journal of Oceanography, Vol. 64 (No. 2), pp. 233-245, 2008

Iron, Manganese and Aluminum in Upper Waters of the Western South Pacific Ocean and Its Adjacent Seas

Hajime Obata1*, Kiminori Shitashima2, Kenji Isshiki3 and Eiichiro Nakayama4

1Ocean Research Institute, University of Tokyo, Minamidai, Nakano-ku, Tokyo 164-8639, Japan
2Central Research Institute of Electric Power Industry, Abiko, Abiko-City, Chiba 270-1194, Japan
3Department of Environmental Science, Kochi Women's University, Eikokuji-cho, Kochi-City, Kochi 780-8515, Japan
4School of Environmental Science, University of Shiga Prefecture, Hassaka-cho, Hikone, Shiga 522-8533, Japan

(Received 30 April 2007; in revised form 31 August 2007; accepted 12 September 2007)

Abstract: Total dissolvable iron, manganese and aluminum distributions in upper waters were determined in the western South Pacific, Solomon Sea, Coral Sea, and Tasman Sea. In these oceanic regions, the surface aluminum distributions well reflect the atmospheric deposition pattern of mineral dust in the western South Pacific reported previously. Surface manganese distributions derive mainly from lateral transportation from the coastal sediments of western tropical islands. Compared to Mn and Al, the Fe distributions reflect the nutrient cycle in upper waters. Iron limitation over the vast South Pacific, as revealed by physiological features of phytoplankton, seems to be caused by low atmospheric dust deposition and low Fe:N ratios in deep waters. In the western South Pacific, with its unique geographic and oceanographic settings, the local sources of trace metals might considerably affect their biogeochemical cycles.

*Corresponding author E-mail: obata@ori.u-tokyo.ac.jp

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