长江口及其邻近海域春秋季浮游植物群落及环境影响因子研究

Community structure and environmental factors of phytoplankton in Changjiang Estuary and adjacent sea in spring and autumn

为了解长江口及其邻近海域海洋生态环境质量的现状,2011年秋季和2012年春季对长江口及其邻近海域的38个站位进行了浮游植物的种类组成、丰度及多样性的调查。并结合同期进行的环境因子调查结果,对长江口及其邻近海域浮游植物与环境因子数据进行了典范对应分析(CCA),以探讨该海域环境因子对浮游植物产生的影响。结果表明:春季共鉴定浮游植物195种,秋季218种,硅藻为主要优势类群,其次为甲藻。中肋骨条藻是调查海域的绝对优势种。春季浮游植物丰度均值为1.23×105/L,秋季丰度均值为7.15×104/L。在水平分布上,春季浮游植物丰度高值区出现在长江入海口;秋季丰度高值区主要出现在外侧海域。调查海域春季的浮游植物多样性指数较低为1.59,秋季为2.23。典范对应分析表明,硅酸盐、磷酸盐、无机氮和盐度是影响长江口及其邻近海域硅藻丰度分布的最重要的生态因子;而透明度、盐度和溶解氧是影响调查海域甲藻丰度分布的最重要的生态因子。

To understand the present environment quality of the marine ecosystem in Changjiang Estuary and adjacent sea, the phyto plankton community structure was studied based on data from 38 stations in autumn 2011 and spring 2012. Combined with the data of environmental factors investigation, canonical correspondence analysis （CCA） was applied to explore the relationship between phyto-plankton species and environmental factors using CANOCO 4.5. The results showed that 195 species were identified in spring, 218 species were identified in autumn, diatom was the dominant group, second was dinoflagellate. Skeletonema costatum was the absolute ly dominant species in Changjiang Estuary and adjacent sea. The average abundance of phytoplankton was 1.23 x 10^5/L in spring, while 7.15 x 10^4/L in autumn. Concerning the horizontal distribution, the abundance was high in Changjiang Estuary in spring, and that was high in offshore area in autumn. The Shannon diversity index was 1.59 in spring and 2.23 in autumn. Based on canonical correspondence analysis, DSi, DIP, DIN and salinity were the main factors affecting diatom in Changjiang Estuary and adjacent sea; while transparency, salinity and DO were the main factors affecting dinoflagellate.