Behavior of particulate materials during iron fertilization experiments in the Western Subarctic Pacific (SEEDS and SEEDS II) |
| |
| Institution: | 1. University of Geneva, Faculty of Science, Earth and Environmental Sciences, Institute F.-A. Forel, Marine and Lake Biogeochemistry, 10 rte de Suisse, 1290 Versoix, Switzerland;2. University of Technology Sydney, Plant Functional Biology and Climate Change Cluster, PO Box 123, Broadway 2007, NSW, Australia;3. CSIRO Materials Science and Engineering, c/o CSIRO Marine and Atmospheric Research, PO Box 1538, Hobart 7001, TAS, Australia;4. CSIRO Ocean and Atmosphere, PO Box 1538, Hobart 7001, TAS, Australia;5. Laboratory of Glaciology, Université Libre de Bruxelles, CP 160/03 Avenue F.D. Roosevelt, 50, B-1050 Bruxelles, Belgium;1. School of Earth and Atmospherics Sciences, Georgia Institute of Technology, 311 Ferst Dr, Atlanta, GA 30332, USA;2. School of Physics, Georgia Institute of Technology, Atlanta, GA 30332, USA;3. Department of Marine Sciences, University of Georgia, Athens, GA 30602, USA;4. Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA 90095, USA;1. Dept. of Earth Sciences, University of Southern California, 3651 Trousdale Pkwy, Los Angeles, CA, 90089, United States;2. RSMAS, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, United States;3. Earth, Ocean and Atmospheric Science Dept., Florida State University, Tallahassee, FL 32306, United States;4. Dept. of Biological Sciences, University of Southern California, 3616 Trousdale Pkwy, Los Angeles, CA 90089, United States |
| |
| Abstract: | During two mesoscale iron-enrichment studies in the northwestern subarctic Pacific (SEEDS in 2001 summer and SEEDS II in 2004 summer), particulate materials from the iron-induced phytoplankton bloom in the upper water column were monitored to analyze the export processes beneath the upper mixed layer, mainly with drifting sediment traps. We could not observe the total downward export process of the high accumulation of particulate organic carbon from the mixed layer induced by the large diatom bloom of SEEDS e.g., Tsuda, A., Takeda, S., Saito, H., Nishioka, J., Nojiri, Y., Kudo, I., Kiyosawa, H., Shiomoto, A., Imai, K., Ono, T., Shimamoto, A., Tsumune, D., Yoshimura, T., Aono, T., Hinuma, A., Kinugasa, M., Suzuki, K., Sohrin, Y., Noiri, Y., Tani, H., Deguchi, Y., Tsurushima, N., Ogawa, H., Fukami, K., Kuma, K., Saino, T., 2003. A mesoscale iron enrichment in the western subarctic Pacific induces large centric diatom bloom. Science 300, 958–961] because the 2-week observation period was too short to examine the decline phase of the bloom. In contrast, in SEEDS II, the particulate organic carbon and particulate organic nitrogen were accumulated 123 and 23 mmol m−2, respectively, in the mixed layer until day-15 (days from iron-enrichment), and then ca. 90% were removed from the mixed layer by day-25. The sediment traps at 40 m depth between day-15 and day-25 accounted for at least more than 35% of these particles. There was no large variation in chemical composition in settling particles above 100 m depth throughout the experimental periods both in SEEDS and SEEDS II. The content of biogenic opal remained more than 50% of all settling particles during SEEDS, while the content of biogenic calcium carbonate was relatively high, with a low biogenic opal content of consistently less than 30% during SEEDS II. These results suggest that high standing stock of seed population of diatoms before the iron fertilization, indicated by low C/Si ratio of particulate matter, is an important factor to induce the large diatom bloom in SEEDS. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
