Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, West Xin(')gang Road 164#, Guangzhou 510301, China.
Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, West Xin(')gang Road 164#, Guangzhou 510301, China.
Sci Total Environ. 2017 Jul 1;589:1-10. doi: 10.1016/j.scitotenv.2017.02.208.
We investigated picoplankton distribution patterns and environmental variables along an east-to-west transect in the northeastern South China Sea (SCS) during late winter 2016, giving us the opportunity to examine the impacts of the Kuroshio intrusion and the associated eddies. The results indicated that the subsurface (50-75m) phytoplankton biomass chlorophyll (Chl a) maximum (SCM) disappeared and was replaced by higher Chl a in the middle part of the transect due to the impacts of the Kuroshio intrusion and mesoscale eddies. Both flow cytometry and pyrosequencing data revealed that picoplankton abundance and community structure were significantly influenced by perturbations in complex physical processes. Picoeukaryotes represented most of the total phytoplankton biomass, and their maximum abundance (>10cellsmL) occurred within cyclonic eddy-affected regions (Stations 11 and 12), whereas the abundance of Prochlorococcus was the lowest in these regions. Prochlorococcus showed a higher abundance in the Kuroshio-affected area, while Synechococcus was mostly distributed at the upper well-lit depths, with its maximum abundance observed in surface waters (0-30m) adjacent to the cyclonic eddy center. Heterotrophic bacteria (HBA) displayed high abundance along the transect, consistent with the total phytoplankton biomass. Phylogenetic analysis revealed 26 bacterial phyla, with major components belonging to Proteobacteria, Cyanobacteria, Actinobacteria, and Bacteroidetes, as well as SAR406. Notably, relatively more Rhodobacterales, Flavobacteriales, Alteromonadales, and Vibrionales that were distributed in surface waters of the cyclonic eddy center were specifically associated with the phytoplankton (mainly picoeukaryotes) bloom. Our study highlights the impacts of the Kuroshio intrusion in regulating the microbial ecology of the northeastern SCS and the potential coupling between phytoplankton and bacteria.
我们在 2016 年冬季后期沿着东北南海（SCS）的东西向断面调查了微微型浮游生物的分布模式和环境变量，使我们有机会研究黑潮入侵及其相关的漩涡的影响。结果表明，由于黑潮入侵和中尺度漩涡的影响，断面中部的次表层（50-75m）浮游植物生物量叶绿素（Chl a）最大值（SCM）消失，取而代之的是更高的 Chl a。流式细胞术和焦磷酸测序数据均表明，微微型浮游生物的丰度和群落结构受到复杂物理过程扰动的显著影响。微微型真核生物代表了总浮游植物生物量的大部分，其最大丰度（>10cells/mL）出现在受气旋涡影响的区域（站位 11 和 12），而在这些区域中，原绿球藻的丰度最低。原绿球藻在黑潮影响的区域丰度较高，而聚球藻主要分布在上层光照充足的深度，其最大丰度出现在与气旋涡中心相邻的表层水（0-30m）中。异养细菌（HBA）在整个断面均表现出高丰度，与总浮游植物生物量一致。系统发育分析显示了 26 个细菌门，主要组成部分属于变形菌门、蓝藻门、放线菌门和拟杆菌门，以及 SAR406。值得注意的是，相对更多的红杆菌目、黄杆菌目、交替单胞菌目和弧菌目，它们分布在气旋涡中心的表层水中，与浮游植物（主要是微微型真核生物）的爆发密切相关。我们的研究强调了黑潮入侵对调节东北南海微生物生态学的影响，以及浮游植物和细菌之间的潜在耦合。
