Abstract The variation law of dissolved silica (DSi), dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) and nutrition structure after the Three Gorges Project (TGP) impounding as well as their ecological effect were analyzed according to monitoring survey of the Yangtze River Estuary in spring (May) and summer (August) from 2004-2009. The results showed that after impounding, DSi and DIN concentration decreased and increased, respectively. During the study period, DSi decreased by about 63%, while DIN almost tripled. DIP concentration fluctuated slightly. With respect to nutrition structure, N:P increased, whereas Si:P and Si:N declined. According to chemometry standard of nutrient limits, nutrition structure tended to be imbalanced and the limiting factor of phytoplankton growth (P) was studied. Changes of nutrition structure have largely decreased diatom and caused different composition of dominant phytoplankton species. This may change ecosystem structure of the Yangtze River Estuary.

中文翻译：

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三峡工程蓄水后长江口DSi和营养结构变化特征及其生态效应

摘要 根据三峡工程蓄水后溶解性二氧化硅（DSi）、溶解性无机氮（DIN）、溶解性无机磷（DIP）和营养结构的变化规律及其生态效应，分析了三峡工程蓄水后的生态效应。 2004-2009年春季（5月）和夏季（8月）长江口。结果表明，蓄水后，DSi和DIN浓度分别下降和上升。在研究期间，DSi 下降了约 63%，而 DIN 几乎增加了两倍。DIP 浓度略有波动。在营养结构方面，N:P增加，而Si:P和Si:N下降。根据营养限度的化学计量标准，营养结构趋于不平衡，研究了浮游植物生长的限制因素（P）。营养结构的变化大大减少了硅藻，并导致优势浮游植物物种的组成不同。这可能会改变长江口的生态系统结构。