2016年夏季长江口邻近海域浮游动物群落结构

根据2016年8月长江口邻近海域27个站位的浮游动物样品数据,对长江口邻近海域的浮游动物群落结构和多样性进行分析,研究了浮游动物群落结构与环境因子的关系.结果表明: 该海区共鉴定出浮游动物93种,隶属于6门12大类群,另有浮游幼体及鱼卵仔鱼15种.其中,桡足类为绝对优势类群,共鉴定出48种,占44.4%;水母类为第二优势类群,共鉴定出12种,占11.1%.该海域出现的主要贡献类群为桡足类、海樽类、毛颚类、枝角类和水母类,平均丰度依次为273.9、115.0、67.1、63.6和61.1 ind·m^-3,其中绝对优势类群为桡足类,贡献率占20.3%.根据环境因子聚类结果,将该海区分为冲淡水影响区和外海水团影响区.单因子相似性分析检验发现,两个区域群落结构差异显著(平均差异性为4.0 %).SIMPER分析发现,对差异性的贡献比例依次是桡足类20.3%、海樽类18.0%、枝角类14.1%、毛颚类13.4%和水母类11.8%.

Community structure of zooplankton in adjacent area of Changjiang Estuary,China in summer 2016.

Based on the data of zooplankton samples from 27 stations in the offshore area of Changjiang Estuary in August 2016, we analyzed the community structure and diversity of zooplankton and examined the relationship between zooplankton community structure and environmental factors. A total of 108 species of zooplankton belonging to 12 groups in six phyla, together with 15 types of pelagic larvae and fish eggs were identified. The main groups were copepods, thaliacea, chaetognaths, cladocladus and medusae, with the average abundance being 273.9, 115.0, 67.1, 63.6 and 61.1 ind·m^-3. The most dominant group of zooplankton was copepods (48 species), accounting for 44.4% of the total zooplankton abundance. Medusae ranked second with a total of 12 species, accounting for 11.1% of the total zooplankton abundance. Furthermore, the absolute dominant group was copepods, with the highest contribution to the zooplankton community (20.3%). According to the clustering results of environmental factors, the area could be divided into Changjiang diluted water and offshore water mass. The results of analysis of similarities showed that the difference of zooplankton community between the two regions was significant (the average diffe-rence was 4%), and the contribution to the difference was 20.3%, 18.0%, 14.1%, 13.4%, and 11.8% for copepod, thaliacea, cladocera, chaetognaths, and medusae, respectively.