四十里湾赤潮高发期营养盐与叶绿素a的年际变化

Annual variation of nutrient and Chla during HABs' periods in Sishili Bay

通过分析四十里湾海域连续6 a（2003～2008年）赤潮高发期（5～9月）的监测数据,发现2003～2008年该海域总无机氮、硅酸盐、COD和叶绿素a含量均呈上升趋势;磷酸盐没有明显的上升或下降趋势;叶绿素a含量与总无机氮浓度、磷酸盐浓度均呈显著的正相关;N/P值明显高于Redfield比值,且逐年上升,显示该海区处于相对的磷限制状态。

The Harmful Algal Blooms （HABs） in the cultivated area of Sishili Bay usually occurred in warm days. The study on the environment state in Sishili Bay in May, Jun. , Jul. , Aug. and Sep. 2003 - 2008 was made. The results showed that the main nutrient loading is from the terrestrial sources. Annual variations of DIN, SiO3 -Si, COD and Chla were lineally increased. Annual variation of PO4 -P was not clearly increased or decreased trend. The correlations between Chla and DIN, PO4-P were significantly positive. Molar N/P ratios were well above Redfield value, showing comparatively P-limitation in this bay.