海洋生态与环境科学重点实验室知识库

      本论文采用流式细胞术对热带西太平洋海山区（雅浦、马里亚纳、卡罗琳和
麦哲伦海山）超微型浮游生物（超微型自养浮游生物：聚球藻、原绿球藻、微微
型真核浮游生物、微型真核浮游生物；异养原核生物：低核酸和高核酸含量异养
原核生物）和浮游病毒的分布特点进行了研究，并分析了影响其分布的可能因素。
       分别对冬季（雅浦海山）、春季（马里亚纳海山）、夏季（卡罗琳海山）、秋季（卡罗琳海山）超微型浮游生物的丰度和生物量进行了调查。聚球藻的丰度范围在 0-3.64×10³ cells mL^-1，季节变化为夏季>春季>秋季>冬季。原绿球藻在四个季节均是丰度最高的超微型自养浮游生物，丰度范围在0.07-176.25×10³ cells mL^-1，季节变化为冬季>夏季>春季>秋季。微微型真核浮游生物的丰度范围在0-5.78×10³ cells mL^-1，季节变化与原绿球藻一致， 冬季>夏季>春季>秋季。微型真核浮游生物的丰度远低于其它超微型自养浮游生物，丰度范围在 0-1.14×10³cells mL^-1，季节分布趋势为秋季>夏季>冬季>春季。 异养原核生物是丰度最高的超微型浮游生物，丰度范围在 0.58-7.32×10⁵ cells mL^-1，季节变化为秋季>夏季>春季>冬季。低核酸和高核酸含量异养原核生物的丰度范围分别在 0.09-3.16×10⁵cells mL^-1 和 0.41-5.20×10⁵ cells mL^-1， 二者的季节变化趋势与总异养原核生物一致。超微型浮游生物各类群的垂直分布模式都与叶绿素 a 荧光值有关。聚球藻丰度的高值出现在叶绿素最大值层（DCM 层）以浅， 冬季高值区最浅（100 m 以浅），春、夏和秋季较深（130 m 以浅）。 原绿球藻和微微型真核浮游生物高值区在 DCM 层附近， 冬季最浅（30 m-130 m 水层）， 秋季最深（100 m-150 m 水层）。微型真核浮游生物和异养原核生物（低核酸和高核酸含量异养原核生物）分布范围较广，表层至 DCM 层丰度较高；冬季高值区最浅（均为 100 m 以浅），秋季最深（微型真核浮游生物： 150 m 以浅， 异养原核生物： 175 m 以浅）。在超微型自养浮游生物中，微型真核浮游生物的生物量在 DCM 层以浅占优势；原绿球藻的生物量在 DCM 层附近占优势。在异养原核生物中，高核酸含量异养原核生物的生物量所占比例高于低核酸含量异养原核生物。超微型自养浮游生物分布没有明显的“海山效应”；低核酸含量异养原核生物所占比例在卡罗琳海山附近升高，意味着海山的存在可能会对异养原核生物亚群的比例产生影响。 冗余分析发现超微型浮游生物（除原绿球藻和微微型真核浮游生物）与温度、盐度呈正相关关系，与营养盐呈负相关关系，表明超微型浮游生物的季节变化与环境因子（温度、盐度和营养盐）的季节差异有关。
       对麦哲伦海山（17.2-17.6°N， 152.5-155.5°E）和马里亚纳海山（11.1-11.5°N，139.1-139.6°E） 超微型浮游生物的分布进行了调查。超微型自养浮游生物的丰度和生物量在马里亚纳海山高于麦哲伦海山； 而异养原核生物的分布正好相反。超微型浮游生物（除聚球藻外） 的高值区在麦哲伦海山均深于马里亚纳海山。 马里亚纳海山超微型自养浮游生物生物量的主要贡献者是微型真核浮游生物和原绿球藻，而麦哲伦海山主要为微微型真核浮游生物和原绿球藻。两座海山超微型浮游生物分布的差异受地理位置的影响，此外海山类型也会对超微型浮游生物的分布造成影响。
       将流式细胞仪405 nm紫色激光的侧向散射光代替传统使用的488 nm蓝色激
光，极大提高了其检测浮游病毒的精确度和分辨率，并将此技术应用到海山区浮
游病毒的检测。在热带西太平洋卡罗琳（浅海山）和麦哲伦（深海山） 海山进行
了浮游病毒研究。 卡罗琳海山总浮游病毒的丰度范围在 0.51-21.11×10⁶ 个 mL^-1,平均值为 5.37±3.75×10⁶ 个 mL^-1；麦哲伦海山总浮游病毒的丰度范围0.31-13.01×10⁶ 个 mL^-1，平均值为 4.99±3.26×10⁶ 个 mL^-1。卡罗琳海山总浮游病毒丰度高于麦哲伦海山。垂直分布上，卡罗琳海山浮游病毒的高值区浅于麦哲伦海山。卡罗琳和麦哲伦海山都检测到 3 至 4 个具有相似的侧向散射光、不同荧光强度的病毒亚群。 本研究发现浮游病毒的亚群在 DCM 层上下有明显的深度相关的分布模式。 表层至 DCM 层， 可观察到 4 个病毒亚群，分别为低荧光病毒（LFV）、 2 个中荧光病毒（MFV-a 和 MFV-b）、高荧光病毒（HFV）； DCM 层至底层，中荧光病毒仅观察到 1 个亚群， 即只有 3 个病毒亚群。 在整个水体中，两座海山均是低荧光病毒在总浮游病毒丰度最高，中荧光病毒次之，高荧光病毒丰度最低； 但在卡罗琳海山 75 m-150 m 水层， 中荧光病毒丰度高于低荧光病毒。两座海山浮游病毒与异养原核生物的比值（VPR） 的垂直分布趋势一致，随水深增加， VPR 值逐渐增大。 海山的地形地貌对浮游病毒的分布有明显影响。在卡罗琳海山，海山站浮游病毒丰度较高，次表层最大值相对较浅， 形成了浮游病毒分布的“海山效应”。浅海山与海流的相互作用将深层营养盐输送到真光层内，此外海山沉积物中的病毒也可以通过再悬浮进入水体，二者共同维持了海山站相对较高的浮游病毒丰度。 麦哲伦海山浮游病毒的分布没有明显的“海山效应”，可能是由于深海山对环境因子的影响以及海山沉积物中病毒的再悬浮均未到达真光层内，没有对浮游病毒分布产生影响。
 

     The ecological distribution characteristics of ultraplankton (autotrophic
ultraplankton: Synechococcus, Prochlorococcus, picoeukaryotes, nanoeukaryotes; heterotrophic prokaryotes: low and high nucleic acid content heterotrophic prokaryotes) and virioplankton in seamount areas (Yap, Mariana, Caroline and Magellan seamounts) of the tropical western Pacific Ocean were analyzed by flow cytometry in laboratory. We also studied the potential influencing factors on ultraplankton and virioplankton distribution.
     The abundance and biomass of ultraplankton were investigated in winter (Yap seamount), spring (Mariana seamount), summer (Caroline seamount) and autumn (Caroline seamount). Synechococcus ranged from 0-3.64×10³ cells mL^-1, with a seasonal variation of summer > spring > autumn > winter. Prochlorococcus was the most abundant autotrophic ultraplankton and ranged from 0.07-176.25×10³ cells mL^-1, with a seasonal variation of winter > summer > spring > autumn. Picoeukaryotes
ranged from 0-5.78×10³ cells mL^-1, with a seasonal variation of winter > summer > spring > autumn. Nanoeukaryotes was the lowest abundant autotrophic ultraplankton and ranged from 0-1.14×10³ cells mL^-1, with a seasonal variation of autumn > summer > winter > spring. Heterotrophic prokaryotes was the most abundant ultraplankton and ranged from 0.58-7.32×10⁵ cells mL^-1, with a seasonal variation of autumn > summer > spring > winter. Low and high nucleic acid content heterotrophic
prokaryotes (LNA and HNA) ranged from 0.09-3.16×10⁵ cells mL^-1 and
0.41-5.20×10⁵ cells mL^-1. The seasonal variation of LNA and HNA was consistent with that of heterotrophic prokaryotes. The vertical distribution pattern of ultraplankton was related to in situ chlorophyll a fluorescence. High abundance of Synechococcus was observed in the upper deep chlorophyll a maximum (DCM) layer. The depths of high abundance of Synechococcus were shallower in winter (upper 100 m water column) and deeper in spring, summer and autumn (upper 130 m water column). Prochlorococcus and picoeukaryotes exhibited maximum abundance in the DCM layer. The depths of maximum abundance of Prochlorococcus and picoeukaryotes were shallowest in winter (30 m-100 m water column) and deepest in autumn (100 m-150 m water column). Nanoeukaryotes and heterotrophic prokaryotes were found abundant in wide distribution from surface to DCM layer. The depths of high abundance of nanoeukaryotes and heterotrophic prokaryotes were shallowest in
winter (upper 100 m water column) and deepest in autumn (nanoeukaryotes: upper 150 m water column, heterotrophic prokaryotes: upper 175 m water column). For the autotrophic ultraplankton, nanoeukaryotes biomass dominated the upper DCM layer, whereas Prochlorococcus biomass dominated the DCM layer. For the heterotrophic
prokaryotes, the percentage of high nucleic acid content heterotrophic prokaryotes biomass was higher than that of low nucleic acid ones. No obvious “seamount effect”was observed in the distribution of autotrophic ultraplankton. The proportion of low nucleic acid content heterotrophic prokaryotes increased near Caroline seamount, which means that the existence of seamount may affect the proportion of the two groups of heterotrophic prokaryotes. Redundancy analysis (RDA) showed that ultraplankton (except for Prochlorococcus and picoeukaryotes) had a positive relationship with temperature and salinity, and a negative relationship with nutrients. This indicated that the seasonal variation of ultraplankton was related to the seasonal difference of environmental factors (temperature, salinity and nutrients).
       The distributions of ultraplankton were investigated in Mariana (11.1-11.5°N, 139.1-139.6°E) and Magellan (17.2-17.6°N, 152.5-155.5°E) seamounts. The abundance and biomass of autotrophic ultraplankton were higher in Mariana seamount than Magellan seamount. However, the trend of heterotrophic prokaryotes was opposite. The depths of high abundance and biomass of ultraplankton (except for Synechococcus) in Magellan seamount were deeper than Mariana seamount. The main
contributors of biomass of autotrophic ultraplankton in Mariana seamount were Prochlorococcus and nanoeukaryotes, whereras Prochlorococcus and picoeukaryotes biomass were dominant in Magellan seamount. The difference of distribution of ultraplankton in two seamounts was affected by geographical location. In addition, the types of seamounts also affected ultraplankton distribution.
     The 405 nm violet side scatter (SSC) replaced 488 nm blue SSC in flow cytometer, which greatly improved the accuracy and resolution of detecting virioplankton. This technology was applied to detect virioplankton in seamount areas. The virioplankton distribution was investigated in Caroline (shallow seamount) and Magellan (deep seamount) seamounts. The total abundance of virus-like particles (VLP) in Caroline and Magellan seamounts were in the range of 0.51-21.11×10⁶ particles mL^-1 and 0.31-13.01×10⁶ particles mL^-1, respectively and the average of VLP were 5.37±3.75×10⁶ particles mL^-1 and 4.99±3.26×10⁶ particles mL^-1, respectively. The virioplankton abundance of Caroline seamount was higher than that of Magellan seamount. The depth of high abundance of virioplankton in Caroline seamount was shallower than that in Magellan seamount. Three to four distinct viral subclusters with similar side scatter but different green fluorescence intensities were identified in two seamounts. Viral subclusters exhibited differences related to depth. From surface to DCM layers, there were four distinct subclusters classified as low fluorescence viruses (LFV), medium fluorescence viruses a and b (MFV-a and MFV-b) and high fluorescence viruses (HFV). From DCM layers to bottom, only one MFV subcluster was resolved. In full water column of two seamounts, LFV comprised the most abundant subclusters, followed by MFV, and HFV constituted the least abundant subcluster. However in Caroline seamount, the MFV abundance was higher than the LFV abundance in 75 m-150 m water column. The vertical distribution of the ratio of virioplankton/heterotrophic prokaryote (VPR) was same in two seamounts. With the increase of water depth, VPR increased. Shallower subsurface peaks and significant virioplankton abundance enhancements were detected at the summit and seamount stations in Caroline seamount, which formed the “seamount effect” of virioplankton. Interactions between the shallow Caroline seamount and the local current transported nutrients into the euphotic zone and viruses in seamount sediments might also be resuspended into water column, which jointly supported higher virioplankton standing stocks. However, there was no obvious “seamount effect” in the distribution of virioplankton in  Magellan seamount. The impact of deep seamount on environmental factors and resuspension of viruses in seamount sediments didn’t reach the epipelagic layer and affect the distribution of virioplankton.
 

第 1 章 引言...............................................................................................1
1.1 海洋超微型浮游生物和浮游病毒.....................................................................1
1.1.1 海洋超微型浮游生物..................................................................................3
1.1.1.1 聚球藻...................................................................................................4
1.1.1.2 原绿球藻...............................................................................................4
1.1.1.3 微微型真核浮游生物...........................................................................5
1.1.1.4 微型真核浮游生物...............................................................................6
1.1.1.5 异养原核生物.......................................................................................6
1.1.2 浮游病毒......................................................................................................7
1.2 海山...................................................................................................................10
1.2.1 海山生态系统............................................................................................10
1.2.2 海山浮游生物研究....................................................................................11
1.3 研究内容和意义...............................................................................................13
第 2 章 材料与方法 ................................................................................15
2.1 研究海区...........................................................................................................15
2.2 理化参数的采集和测定...................................................................................22
2.3 超微型浮游生物采集及测定...........................................................................22
2.3.1 样品采集....................................................................................................22
2.3.2 超微型浮游生物样品分析........................................................................23
2.3.3 浮游病毒样品分析....................................................................................25
2.4 生物量计算.......................................................................................................28
2.5 数据处理方法...................................................................................................30
第 3 章 不同季节热带西太平洋海山区超微型浮游生物的生态分布特
点...............................................................................................................31
3.1 调查海山及站位...............................................................................................31
3.2 结果...................................................................................................................31
3.2.1 环境参数....................................................................................................31
3.2.2 超微型自养浮游生物的丰度及分布特征................................................39
3.2.3 异养原核生物的丰度及分布特征............................................................46
3.2.4 超微型浮游生物生物量............................................................................53
3.2.5 超微型自养浮游生物各类群生物量及百分比........................................55
3.2.6 异养原核生物各类群生物量及百分比....................................................58
3.2.7 超微型浮游生物与环境因子的关系........................................................59
3.3 讨论...................................................................................................................64
3.3.1 热带西太平洋海山区超微型浮游生物的分布模式................................64
3.3.2 超微型自养浮游生物生物量的贡献........................................................66
3.3.3 高核酸和低核酸含量异养原核生物生物量比例的变化及影响因素....66
3.3.4 海山对超微型浮游生物的影响................................................................68
3.3.5 超微型浮游生物的季节变化....................................................................68
3.4 小结...................................................................................................................70
第 4 章 不同经纬度热带西太平洋海山区超微型浮游生物的生态分布
特点...........................................................................................................73
4.1 调查海山及站位...............................................................................................73
4.2 大洋区结果.......................................................................................................73
4.2.1 环境参数....................................................................................................73
4.2.2 超微型自养浮游生物的丰度及分布特征................................................74
4.2.3 异养原核生物的丰度及分布特征............................................................75
4.2.4 超微型浮游生物生物量............................................................................76
4.2.5 超微型浮游生物与环境因子的关系........................................................79
4.3 海山结果...........................................................................................................80
4.3.1 环境参数....................................................................................................80
4.3.2 超微型自养浮游生物的丰度及分布特征................................................83
4.3.3 异养原核生物的丰度及分布特征............................................................85
4.3.4 超微型浮游生物生物量............................................................................88
4.3.5 超微型自养浮游生物各类群生物量及百分比........................................89
4.3.6 异养原核生物各类群生物量及百分比....................................................90
4.3.7 超微型浮游生物与环境因子的关系........................................................91
4.4 讨论...................................................................................................................92
4.4.1 环境因子比较............................................................................................92
4.4.2 超微型浮游生物的比较............................................................................93
4.5 小结...................................................................................................................93
第 5 章 不同海山浮游病毒的生态分布特点 ........................................95
5.1 调查海山及站位...............................................................................................95
5.2 结果...................................................................................................................95
5.2.1 水文环境....................................................................................................95
5.2.2 病毒亚群....................................................................................................98
5.2.3 浮游病毒丰度............................................................................................99
5.2.4 浮游病毒的分布........................................................................................99
5.2.5 卡罗琳海山海山站和大洋站浮游病毒比较..........................................105
5.2.6 浮游病毒的影响因素..............................................................................110
5.3 讨论.................................................................................................................113
5.3.1 病毒亚群..................................................................................................113
5.3.2 海山对浮游病毒的影响..........................................................................117
5.3.3 VPR...........................................................................................................118
5.4 小结.................................................................................................................119
第 6 章 结论与展望 ..............................................................................121
6.1 主要结论.........................................................................................................121
6.2 创新点.............................................................................................................122
6.3 展望.................................................................................................................122
参考文献.................................................................................................123
致谢.........................................................................................................137
作者简历及攻读学位期间发表的学术论文与研究成果....................139