2012年夏季韭山列岛附近海域初级生产力估算及其与环境因子的关系

于2012年8月对韭山列岛附近海域浮游植物生物量、叶绿素a浓度进行现场调查,并估算初级生产力水平。结果表明:夏季韭山列岛附近海域浮游植物的细胞丰度为0.4×103~1 225.0×103个/m3,平均68.9×103个/m3,尖刺菱形藻为第一优势种;叶绿素a含量为2.2~9.0 mg/m3,平均5.8 mg/m3,初级生产力含量变化范围在170.94~1 083.10 mg/m3·d之间,平均629.46 mg/m3·d,初级生产力分布特征与叶绿素a基本保持一致,由于真光层深度的差异造成两者峰值出现的站位相异。相关性分析表明初级生产力与叶绿素a、透明度、化学需氧量、无机氮呈现显著正相关,与盐度呈负相关;夏季携带高营养盐的长江冲淡水南下与近岸沿岸流的共同作用与浙江沿岸流、海区上升流以及台湾暖流三种水系在该海域的交汇形成海洋锋区是高初级生产力区形成的主要原因,光照条件和营养盐含量是调查海域初级生产力的主要控制因素。

Estimation on Primary Productivity and Relations with Influencing Factors in the Waters Off Jiushan Islands in Summer 2012

Based on the investigation of phytoplankton biomass, Chlorophyll-a（Chl-a） concentration and primary productivity （PP） in the waters off Jiushan Islands in summer 2012, this paper concluded that the cell abundance of the phytoplankton was 0.4×10^3-1 225.0×10^3 ind/L, 68.9×10^3 ind/L for average, Nitzschia pungens was the first dominant species. The content of Chl-a and PP ranged respectively from 2.2 to 9.0 mg/m 3 and 170.94 mg/m3·d to 1 083.1 mg/m3·d, 629.46 mg/m^3·d and 5.8 mg/m^3 for average of each. Horizontal distribu-tions of PP went in accordance with Chl-a despite the stations of top values differed due to the difference of the euphotic depth. Correlation analysis between PP and influencing factors indicated that PP showed signifi-cant positive correlation with transparency, COD, DIN and that negative with salinity. The co-effect of the con-vergence of Changjiang Diluted Water, with high value of nutrients and the coastal current as well as the con- 〈br〉 vergence of Zhejiang Coastal Current, Upwelling area and Taiwan Warm Current resulted in the high value of PP in the sea area. Irradiance and nutrients were the two dominant factors of PP in the area.