摘要
由于沿海经济的快速发展,人为活动影响加重,长江口海区富营养化程度和范围逐年加重和扩大,已经成为我国有害赤潮高发区之一,有记录的赤潮事件约1/4发生在这个海区(周名江等,2003),从而引起了科学家们的高度重视。赤潮的发生很大程度上与营养盐时空分布特征密切相关(Hodgkiss et al.,1997)。
Based on the data obtained from quarterly investigations in the Changjiang estuary and its adjacent sea areas in 2004,the distributions and variations of SiO_3-Si are discussed.The results show that the concentrations of SiO_3-Si were higher near the Changjiang estuary and lower outside the sea.Generally,the concentrations of SiO_3-Si were higher in the surface than in the bottom in shore;the opposite distributions off shore.The SiO_3-Si concentrations both inside and outside the mouth in summer and autumn were higher than those in spring and winter. Distributions of SiO_3-Si varied with increase and decrease of runoff and with enlarge and reduce of the extent of Changjiang dilution water.The concentrations of SiO_3-Si in May were relatively less because of phytoplankton blooming.The seasonal variations of SiO_3-Si/ DIN and SiO_3-Si/PO_4-P ratios were mainly controlled by the variations of SiO_3-Si concentrations. Compared with the data of 1985-1986,the concentrations of SiO_3-Si have increased 2.3 times,both SiO_3-Si/DIN and SiO_3-Si/PO_4-P ratios have ascended 1.6 and 2.5 times respectively, which depended on the increasing of the SiO_3-Si concentrations.May is the fitting season of phytoplankton blooming compared with other seasons,in which it is the relatively least that SiO_3-Si/DIN and SiO_3-Si/PO_4-P ratios departure from Redfield ratios.The removals of SiO_3-Si in the estuary showed that aside from biological removal,there was a main effect coming from seawater dilution.
出处
《海洋科学集刊》
CAS
2009年第1期10-18,共9页
Studia Marina Sinica
基金
中国科学院知识创新工程重要方向资助项目(KZCX3-SW-232)
国家自然科学重点基金资助项目(50339040)
国务院三峡工程建设委员会资助项目(SX2004-010)
