中文摘要：

分别对2006年6月、8月和10月东海低氧区及邻近海域（26°N～34°N，120°E～126°E）进行综合调查，探讨了东海低氧区及邻近海域固氮蓝藻物种、丰度与分布变化特征。调查区蓝藻主要物种有铁氏束毛藻（Trichodesmium thiebautii）、汉氏束毛藻（Trichodesmium erythraeum）和红海束毛藻（Trichodesmium hildebrandtii），在个别区域检测到胞内植生藻（Richelia intracellu～laris），铁氏束毛藻为优势物种。8月蓝藻细胞丰度最大，藻丝体和细胞平均丰度为12．58×10^3和954．67×10^5 cells／L，其次是10月，藻丝体和细胞平均丰度为44．08×10^3 fikaments／L和68．37×10^5 cells／L，最低为6月，藻丝体和细胞平均丰度为1．07×10^3／L和1．53×10^5 cells／L。蓝藻主要分布在靠近外海受台湾暖流影响的海区，在靠近长江河口透明度较低的区域蓝藻丰度很低，甚至在河口门区未检测到蓝藻，垂直分布特征为主要分布在水深50m以上，丰度高值区域为表层和10m。环境因子中温度对蓝藻生长具有明显的影响，6月时温度与蓝藻丰度呈显著正相关。盐度与蓝藻丰度没有相关性。

英文摘要：

A multi-disciplinary investigation were carried out in June, August and October 2006 in hypoxia area and adjacent waters in the East China Sea （26-34°N, 120-126°E）. Species, quantities and distributions of nitrogen-fixing cyanobacteria were discussed. Results indicated that main species included Trichidesmium thiebautii, Trichiclesmium erythraeum, and Trichidesmium hildebrandtii. Intracellular cyanobiont Richelia intracellularis was de- tected at several sampling stations in the open water area. Trichidesmium thiebautii, was the dominant species. Nitrogen-fixing cyanobacteria cell quantity was the richest in August, trichome and cell abundances were 12.58 103/L and 954.67 10S/L respectively. The quantity was poorest in June, and trichome and cell abundances were 1.07 103/L and 1.53 10S/L respectively. It was richer in August than in June, trichome and cell abundances were 44.08 103/L and 68.37 10s/L respectively. Features of cyanobacteria distributions were described, cyanobacteria enriched along open waters controlled by Tanwan Current, lacked in the Yangzi River Estuary and adjacent area, even not detected at the mouth of the Yangzi River. Vertically cyanobacteria mainly inhabited 0m-50m waters, and the value region was 0m-10m. The environmental temperature influenced the propagation of nitrogen-fixing cyanobacteria markedly, and there was positively significant correlation between them in June, hut there was no correlation between cyanobacteria abundances and the salinity in the investigation.