" 本申請案為東海長期觀測與研究（三）整合型計畫中的子計畫七，基於總計劃所列的整體研究目標，申請人擬利用未來三年驗證兩個相關的假說。第一個工作假說是長江流量的高低必然會改變東海超微藍綠藻的生物量與種類組成。每年於長江高流量時期及低流量時期將利用研究船進行採樣，然後測量水樣中超微藍綠藻的生物量、生長率、以及遺傳組成。其中遺傳組成一項將以16S rDNA的序列來判定。最後將這些資料與河流輸出之流量、水文、營養鹽等資料進行相關分析，以歸納超微藍綠藻所受到的影響。第二個工作假說是亞洲沙塵暴輸送的氮與鐵會刺激東海貧營養鹽海域超微藍綠藻的生長。計畫於每年沙塵暴發生頻度最高的時機 (春天3 - 5月)，於東海貧營養鹽水域進行為期一個月的海上觀測與培養實驗。除了比較沙塵暴前後超微藍綠藻群聚特徵的變化之外，還將利用鐵限制指標基因idiA與氮限制指標基因ntcA的表現量來深入瞭解沙塵暴影響海洋生態系的作用機制。 " " This proposal is the branch project 7 in the joint research project 「Long-term observation and research of the East China Sea – III」. Based on research goals listed in the master project, the proposed research plans to test 2 related hypotheses in a period of 3 years. The first hypothesis is that the fresh water discharge of Changjiang will inevitably alter the biomass and composition of picophytoplankton in the East China Sea. Oceanographic cruises will be conducted during high- and low-discharge periods of Changjiang. Picophytoplankton will be investigated with respect to their biomass, growth rates, and genetic diversity, which will be determined by sequence analysis of 16S rDNA. Such obtained information will be correlated to freshwater discharge, hydrography, and nutrient concentrations to deduct their influences on picophytoplankton. The second working hypothesis is that iron and nitrogen brought by Asian dust storms will stimulate the growth of picoplankton in the oligotrophic region of the East China Sea. During the dust storm season in each year (March to May), a one-month observation with on-deck incubations will be conducted in the East China Sea. In addition to comparing community characteristics of picoplankton before and after a dust storm event, the expression levels of an iron-deficiency indicator gene, idiA, and a nitrogen-deficiency indicator gene, ntcA, will be measured in order to obtain an in-depth understanding of the mechanisms that cause the marine ecosystem to change. "