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分别于2014年春、秋和2015年夏3个季节对南海东北部A站位(118°E,21.5°N)分粒级叶绿素a浓度和超微型光合生物(原绿球藻、聚球藻和超微型真核藻类)细胞丰度的昼夜变化进行了24 h时间序列连续观测和分析。通过萃取荧光法分析叶绿素a浓度,发现叶绿素a浓度呈现明显的昼夜变化,春季正午最高,秋季和夏季基本变化趋势为白天升高,夜晚降低;而因夏季中午的光抑制作用,叶绿素a的浓度相对较低。超微型光合生物(0.2~3μm)对总叶绿素a的贡献最高(71.49%),小型浮游植物(20μm)贡献率最低(10.41%)。通过流式细胞技术检测到3个超微型光合生物类群;其中,原绿球藻为优势类群,最大细胞丰度达1.05×10~5cells/m L,其次是聚球藻,超微型真核藻类的细胞丰度最低,但由于其单位细胞内的叶绿素a含量高,所以可能对叶绿素a的贡献最大。聚球藻丰度基本上白天下降,傍晚到午夜上升;秋季和夏季,超微型真核藻类的丰度白天高,夜晚低,而春季则相反;原绿球藻在秋季和春季的昼夜变化规律和超微型真核藻类相似。在多种因素共同影响下,光照是调控叶绿素a浓度和超微型光合生物丰度昼夜变化的一个关键因素。季节变化上,原绿球藻的细胞丰度季节间没有统计学差异(P0.05),聚球藻的季节变化为秋夏春,超微型真核藻类的季节变化规律和聚球藻相反。 相似文献
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Standing stock of phytoplankton and primary productivity in Penaeus orientalis larval multiplication releasing area of the Xiangshan Bay 总被引：1，自引：1，他引：0
INTRODUCTIONTheXiangshanBayisoneoftheimportantmarineaquaculturebasesinZhejiang.Since1982,themultiplicationreleasingexperimentsofPenaeusorzentalisKishinouyelarvalhavebeencarriedoutinthebay.Thestudyonthephytoplankton,chlaconcentrationandproductivityandthelifepatternofreleasedlarvaeprawnintheXiangshanBayisoneoftheimportanttasksoftheNationalKeyProject--AquaticExploitationTechniqueResearchinLakesandHarbors.TherearemanylargebaysandharborsalongChina'scoast,butonlyafewobservationshavebeend… 相似文献
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To investigate the seasonal variation and community structure of nano- and microzooplankton in Gyeonggi Bay of the Yellow Sea, the abundance and carbon biomass of nano- and microzooplankton were evaluated at 10-day intervals from January 1997 to December 1999. Four major groups of nano- and microzooplankton communities were classified: heterotrophic ciliates, heterotrophic dinoflagellates (HDF), heterotrophic nanoflagellates (HNF), and copepod nauplii. The total carbon biomass of nano- and microzooplankton ranged from 10.2 to 168.8 μg C L−1 and was highest during or after phytoplankton blooms. Nano- and microzooplankton communities were composed of heterotrophic ciliates (7.4–81.4%; average 41.7% of total biomass), HDF (0.1–70.3%; average 26.1% of total biomass), copepod nauplii (1.6–70.6%; average 20.7% of total biomass), and HNF (0.8–59.5%; average 11.5% of total biomass). The relative contribution of individual components in the nano- and microzooplankton communities appeared to differ by seasons. Ciliates accounted for the most major component of nano- and microzooplankton communities, except during summer and phytoplankton blooming seasons, whereas HDF were more dominant during the phytoplankton blooming seasons. The abundance and biomass of nano- and microzooplankton generally followed the seasonal dynamics of phytoplankton. The size and community distribution of nano- and microzooplankton was positively correlated with size-fractionated phytoplankton. The carbon requirement of microzooplankton ranged from 60 to 83% of daily primary production, and was relatively high when phytoplankton biomass was high. Therefore, our result suggests that the seasonal variation in the community and size composition of nano- and microzooplankton appears to be primarily governed by phytoplankton size and concentration as a food source, and their abundance may greatly affect trophic dynamics by controlling the seasonal abundance of phytoplankton. 相似文献
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东海、南黄海浮游植物粒级结构及环境影响因素分析 总被引：7，自引：0，他引：7
对粒径分级叶绿素a含量进行分析,探讨了南黄海和东海海域2000年秋季表层浮游植物的粒级结构特征及其环境影响因素.在整个调查海域范围内,叶绿素a平均含量为0.72 mg*m-3,各粒级浮游植物叶绿素a含量对叶绿素a总量的贡献有显著差异,小型(Microplankton,>20 μm)、微型(Nanoplankton,3～20 μm)和微微型(Picoplankton,0.45～3 μm)浮游植物的贡献率分别为31.2%,49.0%和19.8%.小型浮游植物主要分布在江苏沿岸和长江口附近;微型浮游植物在整个海域的分布较均匀,以浙江沿岸和南黄海东部为高值区;微微型浮游植物主要分布在南黄海中部和东海东南部.通过浮游植物粒径分级叶绿素a和环境因子的相关性分析,发现在调查海域营养盐与浮游植物叶绿素a的相关系数随着浮游植物粒径的增大而从负逐渐变正,说明高的营养盐含量区域较大粒径的浮游植物占有较大优势.依据浮游植物粒径分级叶绿素a和环境因子对调查站位进行的聚类分析结果和海域水团的分布以及卫星遥感图显示的水色差异之间有密切联系,聚类分析方法是研究浮游植物分布和环境因子之间关系的一种有效方法. 相似文献
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The investigation of size-fractionated chlorophyll a and primary productivity were carried out in three longitudinal sections (63°-69°12'S, 70°30'E, 73°E and 75(30'E) at December 18-26, 1998 and January 12-18, 1999 in Prydz Bay and its north sea area, Antarctica. The results showed that surface chlorophyll a concentration were 0. 16 -3. 99 μg dm-3. The high values of chlorophyll a concentration (more than 3.5 μg dm -3) were in Prydz Bay and in the west Ladies Bank. The average chlorophyll a concentration at sub-surface layer was higher than that at surface layer; its concentration at the deeper layers of 50 m decreased with increasing depth and that at 200 m depth was only 0. 01 -0. 95μg dm -3. The results of size-fractionated chlorophyll a showed that the contribution of the netplanktion to total chlorophyll a was 56% , those of the nanoplankton and the picoplankton were 24% and 20% respectively in the surveyed area. The potential primary productivity at the euphotic zone in the surveyed area wa 相似文献
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Christine Dupuy Agathe Talarmin Hans J. Hartmann Daniel Delmas C. Courties Elise Marquis 《Estuarine, Coastal and Shelf Science》2011
In order to investigate the parameters controlling the heterotrophic protists (nano-microzooplankton) on the continental shelf of the southern Bay of Biscay, plankton communities and their physico-chemical environment were studied 4 times in February, April, June and September–October 2004 at three stations in the euphotic zone in the Bay of Biscay. The abundance and carbon biomass of heterotrophic protists (ciliates, heterotrophic dinoflagellates and nanoflagellates) as well as all the others groups of plankton (picoplankton, nanophytoplankton, diatoms, autotrophic dinoflagellates, metazoan microzooplankton and mesozooplankton), the environmental parameters and the primary and bacteria production were evaluated at each sampling period. Microzooplankton grazing experiments were undertaken at the same time. Ciliates and heterotrophic dinoflagellates accounted for the main major component of nano- and microzooplankton communities in term of biomass. The total carbon biomass of heterotrophic protists was highest in spring and lowest at the end of summer. The development of heterotrophic protists started after a winter microphytoplankton bloom (principally large diatoms), the biomass was lower in June and was low in September (through inappropriate prey). The carbon requirement of microzooplankton ranged from 50 to more than 100% of daily primary, bacterial and nanoflagellate production. The heterotrophic protist community was predominantly constrained by bottom-up control in spring and at the end of summer via food availability and quality. 相似文献
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Alexandrine Pannard Pascal ClaquinCécile Klein Bertrand Le RoyBenoît Véron 《Estuarine, Coastal and Shelf Science》2008
The short-term dynamics (time scale of a few days) of phytoplankton communities in coastal ecosystems, particularly those of toxic species, are often neglected. Such phenomena can be important, especially since these very species can endanger the sustainability of shellfish farming. In this study, we investigated the short-term changes in phytoplankton community structure (species succession) in two coastal zones in parallel with physical and chemical conditions. Mixing events with allochtonous waters could thus be distinguished from local processes associated with population growth when it was associated with a change in light or nutrient limitation. Mixing events and water advection influenced fluctuations in total phytoplankton biomass and concentration of dominant species, while local processes influenced delayed changes in community structure. The estuarine species Asterionellopsis glacialis increased in concentration when the water mass mixed with the nearest estuarine water masses. The biological response, measured as photosynthetic capacity, occurred after a time-lag of a few hours, while the changes in community structure occurred after a time-lag of a few days. Finally, the coastal water mass was constantly mixed with both the nearest estuarine and marine water masses, leading in turn to delayed changes in phytoplankton community structure. These changes in species composition and dominance were observed on a time scale of a few days, which means that some toxic species may be missed with a bi-weekly sampling strategy. 相似文献
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198 9/1 990年夏季作者在中国第六次南极考察环极航行中 ,对南大洋不同海区的浮游植物细胞大小分级叶绿素 a和初级生产力、颗粒有机碳及有关环境参数进行了测定。结果表明 ,在南极水域中以南大西洋最为肥沃 ,叶绿素 a浓度平均超过 2 μg/dm3 ,POC的平均浓度也最高 (>1 0 0 μg/dm3 ) ,而德雷克海峡和南印度洋较低。叶绿素 a和 POC的空间变异具有同步的波动。分级叶绿素 a结果表明 ,在肥沃的南大西洋以细胞 >2 0 μm的绢滤浮游生物 (主要是小型浮游生物 )所占比重最高 (6 5 %) ,而在较贫瘠的南印度洋则以微微型浮游生物 (<2 μm)最高 (47%)。分级初级生产力的结果表明 ,在南大西洋和德雷克海峡对总初级生产力的贡献以微微型浮游生物为最大 ,微型浮游生物和小型浮游生物的贡献大致相当。微微型浮游生物相对高的光合作用生理活性显示了它们在南大洋海洋生态系中的重要性。与南极水域相比 ,亚南极和亚热带水域较为贫瘠。 相似文献