黄东海夏秋季微小型浮游动物群落结构变动及与沙海蜇旺发的关系

	黄东海夏秋季微小型浮游动物群落结构变动及与沙海蜇旺发的关系
	李洁
学位类型	硕士
导师	徐奎栋
	2016-05-25
学位授予单位	中国科学院大学
学位授予地点	北京
学位专业	工程硕士
关键词	黄东海+沙海蜇+纤毛虫+桡足类无节幼体+食物基础
摘要	大型水母沙海蜇（Nemopilema nomurai）旺发已经成为近年来黄东海一个常见的生态现象。微小型浮游动物包括粒径在2-20 μm之间的微型浮游动物（主要为异养微型鞭毛虫）和20-200 μm的小型浮游动物（主要包括纤毛虫、异养腰鞭毛虫和桡足类无节幼体等），是“微食物环”与传统食物网物质循环和能量流动的纽带。然而，微小型浮游动物尤其是纤毛虫与沙海蜇旺发的相互作用关系依然不明。本研究以黄东海（120.5°-124.5°E, 29°-37°N）为研究区域，利用2012年10月（沙海蜇衰亡期），2013年6月（沙海蜇旺发初期）、8月和9月（旺发期）4个航次采集的水体样品，现场采样固定和实验室沉降浓缩，通过DAPI荧光染色定量分析（自养和异养微型鞭毛虫）和直接镜检鉴定和计数（纤毛虫、桡足类无节幼体以及夜光虫），研究了黄海和东海四个时段大面站表层和10米层的自养和异养微型鞭毛虫、纤毛虫、桡足类无节幼体及夜光虫的丰度、生物量及生产力等群落结构参数，并结合环境因子探讨了其与水母旺发的相互作用关系。微型鞭毛虫研究显示，表层微型鞭毛虫（0-20 μm）总丰度和总生物量的季节变化表现为：2012年10月（718±314 ind·mL^-1, 40.54±15.14 mg·C·L^-1）> 2013年6月（381±234 ind·mL^-1, 8.49±7.89 mg·C·L^-1）> 2013年8月（222±164 ind·mL^-1, 6.80±6.31 mg·C·L^-1）> 2013年9月（160±102 ind·mL^-1, 5.27±6.39 mg·C·L^-1）。10米层的微型鞭毛虫丰度和生物量的季节分布和表层类似，2012年10月份和2013年9月份略低，2013年6月和8月丰度和生物量相对表层更高。2013年6月份表层、2013年9月表层和10米层自养微型鞭毛虫丰度和生物量与温度及盐度呈负相关关系。纤毛虫共检获纤毛虫38属72种。4个航次纤毛虫的丰度、生物量以及生产力变化较大，但季节分布近似，纤毛虫表层与10米层均在长江口邻近海域和C、E断面近岸站位为高值区域，G断面（34°N）近岸站位为低值区。2012年10月，纤毛虫丰度和生物量在表层为（3184±2620 ind·L^-1, 6.78±4.07 mg·C·L^-1），10米层为（2490±2064 ind·L^-1, 7.08±6.09 mg·C·L^-1）；2013年6月较2012年10月份丰度减少，生物量增加，表层为（2439±2679 ind·L^-1, 12.79±16.89 mg·C·L^-1），10米层为（1516±1126 ind·L^-1, 10.76±14.47 mg·C·L^-1）；2013年8月份最低，表层仅为（1193±1318 ind·L^-1, 4.78±5.23 mg·C·L^-1），10米层为（898±904 ind·L^-1, 3.55±3.253 mg·C·L^-1）；9月份表层纤毛虫丰度较8月份丰度急剧升高，表层为（3088±4623 ind·L^-1, 9.52±9.97 mg·C·L^-1），10米层为（2098±2339 ind·L^-1, 5.20±4.88 mg·C·L^-1）。纤毛虫在四个航次均有较高的生产力，2012年10月表层为 10.48±6.83 μgC·L^-1·d^-1，10米层为 9.38±6.84 μgC·L^-1·d^-1；2013年6月最高，表层为 16.07±17.26 μgC·L^-1·d^-1，10米层为 13.34±15.36 μgC·L^-1·d^-1；2013年8月较6月减少表层为 9.86±10.18 μgC·L^-1·d^-1，10米层为 12.49±12.76 μgC·L^-1·d^-1；2013年9月表层较8月略减至 9.82±10.53 μgC·L^-1·d^-1，10米层为 10.27±9.74 μgC·L^-1·d^-1。基于纤毛虫物种-丰度聚落分析结果表明，黄海海域A、C、E、G断面与长江口邻近海域M、K、PN、Q断面在4个航次明显分开。2013年6月、8月和9月三个航次黄东海表层I、G和E断面样品的纤毛虫物种-丰度聚类分析结果显示，沙海蜇旺发初期与沙海蜇旺发期纤毛虫的群落结构发生了明显的分开。在2013年三个航次的相关分析统计显示，纤毛虫与温度、盐度、自养和异养微型鞭毛虫丰度及生物量中的一个或多个因子有显著相关关系。2013年9月份红色中缢虫在I、K和M等断面的多站位丰度增加，推测水母分泌及消亡产生的营养物质促进其增殖，而水母通过摄食中小型浮游动物产生的级联效应也可导致其丰度增加。桡足类无节幼体和夜光虫本研究在4次调查航次中，仅在2013年6月和8月检出桡足类无节幼体，且表层及10米层桡足类无节幼体的生物量（0.13±0.18 mg·C·L^-1, 0.10±0.14 mg·C·L^-1）和生产力（0.03±0.04 μgC·L^-1·d^-1, 0.03±0.05 μgC·L^-1·d^-1）均远小于纤毛虫的生物量和生产力。在四次调查中表层夜光虫丰度最高值在2013年6月（2279 ind·L^-1）明显高于2013年8月（660 ind·L^-1）和9月（140 ind·L^-1），这可能系8月和9月表层温度高于26℃，不适于夜光虫生长所致。本研究表明，在南黄海水母发生过程中，纤毛虫生物量和生产力均远高于桡足类无节幼体的生物量和生产力。纤毛虫的数量优势可使其较个体数量明显较少的桡足类无节幼体更易为沙海蜇等大型水母所摄食利用，其高生产力为水母的旺发提供了一定的食物基础。黄东海表层I、G和E断面的纤毛虫物种-丰度聚类分析结果显示，2013年6月的纤毛虫群落结构与8月和9月纤毛虫群落结构有明显差异。基于水母旺发前与旺发中微小型浮游动物的丰度、生物量及生产力等群落结构参数及变化，推测纤毛虫为水母旺发提供了重要的食物支撑，并受到水母旺发的直接和间接（级联效应）影响。
其他摘要	The mass occurrence of giant jellyfish Nemopilema nomurai has become a common phenomenon in the Yellow Sea and East China Sea in recent years. Nanoplankton (mainly phototrophic and heterotrophic nanoflagellates) and microplankton (mainly dinoflagellates and ciliates) has long been considered as important mediators of matter circulation and energy flow from the microbial loop to classic food web. However, relationship between nano- and micro-zooplankkton in particular ciliate and the giant jellyfish remains unclear. Abundance, biomass, productivity and the community structure of nano- and microzooplankton (flagellates, ciliates, copepod nauplii, Noctiluca scintillans) in surface and 10m layer water in the Yellow Sea and East China Sea were investigated through sampling and observing under microscope during the jellyfish decaying in October 2012 and the jellyfish fast growth and spreading in June, blooming in August and September 2013 and their relationships with jellyfish bloom and environment factors were discussed. Nanoflagellates Total abundance and biomass of flagellates in the surface water among the four investigations show Octuber 2012 (718±314 ind·mL^-1, 40.54±15.14 mg·C·L^-1) > June 2013 (381±234 ind·mL^-1, 8.49±7.89 mg·C·L^-1) > August 2013 (222±164 ind·mL^-1, 6.80±6.31 mg·C·L^-1) > September 2013 (160±102 ind·mL^-1, 5.27±6.39) mg·C·L^-1, same result was showed in the 10m water. Both abundance and biomass of PNF (prototrophic nano-flagellates) in surface water in June 2013 and in surface and 10m water in September 2013 had negative correlation with tempreture as well as salinity. Ciliates A total of 72 species belonging to 38 genera were sorted. The abundance and biomass of ciliates were respectively (3184±2620 ind·L^-1, 6.78±4.07 mg·C·L^-1), in the surface water and (2490±2064 ind·L^-1, 7.08±6.09 mg·C·L^-1) in the 10m water in October 2012, changed to (2439±2679 ind·L^-1, 12.79±16.89 mg·C·L^-1) in surface water and (1516±1126 ind·L^-1, 10.76±14.47 mg·C·L^-1) in the 10m water in June 2013, sharply decreased to (1193±1318 ind·L^-1, 4.78±5.23 mg·C·L^-1) in surface water and (898±904 ind·L^-1, 3.55±3.53 mg·C·L^-1) in 10m water in August 2013 and boost up to (3088±4623 ind·L^-1, 9.52±9.97 mg·C·L^-1) in the surface water and (2098±2339 ind·L^-1, 5.20±4.88 mg·C·L^-1) ind·L^-1 in 10m water in September 2013。The productivity of ciliates were respectively 10.48±6.83 μgC·L^-1·d^-1 in surface water and 9.38±6.84 μgC·L^-1·d^-1 in the 10m water in October 2012, incresead to 16.07±17.26 μgC·L^-1·d^-1 in surface water and 13.34±15.36 μgC·L^-1·d^-1 in the 10m water in June 2013, quickly droped to 9.86±10.18 μgC·L^-1·d^-1 in surface water and 12.49±12.76 μgC·L^-1·d^-1 in the 10m water in August 2013, slightly decreased to 9.82±10.53 μgC·L^-1·d^-1 in surface water and 10.27±9.74 μgC·L^-1·d^-1 in the 10m water in September 2013. Four investigation shows that ciliates in the surface and 10m water had much greater abundance, biomass and productivity in the adjacent sea area of Changjiang estuary and the nearshore stations at the transects of C (36°N) and E (35°N), and had less abundance, biomass and productivity in the nearshore stations at the transect of G (34°N). Cluster analysis based on ciliate species-abundance in June, August and Seotember 2013 shows that there was a steady difference in community structure between transects in the Norhern Yellow Sea and transects in the Southern Yellow Sea and the East China Sea which is deeply influenced by the Changjiang Runoff. Cluster analysis based on ciliate species-abundance at transects E, G and I in June, August and September 2013 shows that there is a clear difference in community structure between the initial stage of jellyfish bloom (June 2013) and the increase and the mass occurance of jellyfish (August and September 2013). Abundance, biomass and productivity of ciliates have no steady correlation with tempreture, salinity as well as abundance and biomass of PNF and HNF. We assume that the nutrients relased by dead jellyfish and predation of mesozooplankton eventually contribute to the hugely increase of the abundance of Mesodinium rubrum in September 2013. *Noctiluca scintillans* & Copepod nauplii Copepod nauplii were found only in June and August 2013. Both the biomass (0.13±0.18, 0.10±0.14 mg·C·L^-1) and productivity (0.03±0.04, 0.03±0.05 μgC·L^-1·d^-1) were far less than those of ciliates. The abundance of Noctiluca scintillans in June 2013 was much more than that in August and September 2013 which may be caused by the temperature difference. The study shows that the biomass and productivity of ciliates are much more than that of copepod nauplii during the mass occurrence of giant jellyfish in 2013. Compared with copepod nauplii, ciliates have quantitative advantage which makes it easier for giant jellyfish to prey and its high productivity serve food during mass occurrence of giant jellyfish. Based on the dynamics of the ciliate community structure and production before and during the mass occurrence of Nemopilema nomurai, we conclude that ciliates might provide important food supply for the giant jellyfish, and were affected by the giant jellyfish directly and indirectly (cascading) effect.
学科领域	海洋浮游微生物多样性
语种	英语
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/112566
专题	海洋生物分类与系统演化实验室
作者单位	中国科学院大学+海洋研究所
推荐引用方式 GB/T 7714	李洁. 黄东海夏秋季微小型浮游动物群落结构变动及与沙海蜇旺发的关系[D]. 北京. 中国科学院大学,2016.

条目包含的文件
文件名称/大小	文献类型	版本类型	开放类型	使用许可
黄东海夏秋季微小型浮游动物群落结构变动及（26588KB）	学位论文		限制开放	CC BY-NC-SA	浏览