AMMONIUM UPTAKE AND REGENERATION FLUXES OF THE MICROPLANKTON COMMUNITIES IN JIAOZHOU BAY

The results from four cruises（Nov.1991—Jul.1992）to examine fluxes of ammonium uptake andregeneration in the surface layer of Jiaozhou Bay are presented.Seasonal variations of the two fluxeswere in the order:summer】spring】autumn】winter.Diel patterns were characterized by higher uptake inthe daytime and higher regeneration at night.Averaged uptake and regeneration fluxes on an annual scalewere 0.073 and 0.053 μmol·L-1·h-1respectively.Regeneration fluxes were always less than uptakefluxes throughout the year.The longest turnover time was 16.34 d（in winter）,and the shortest one was0.68 d（in summer）.The major uptake flux was contributed by the smallest fraction-picoplankton.Theextents of light-dependence of ammouium uptake by different size fractions were in the order:netplankton】nanoplankton】picoplankton..

Identification of Microplankton in South China Sea with Image-Matching Individual PCR

In this study, marine microplankton were identified by combining standard light microscopy with Sanger 18S rRNA gene sequencing. The image-matching individual PCR technique was applied to identify the image collectable unicellular microplankton to genera. Instead of pure strain culture and morphological identification, microplankton individual cells were isolated and fixed with glutaraldehyde, frozen and stored for months. Finally, they were imaged under a microscope and molecularly identified via phylogenetic analysis of their 18S ribosomal RNA gene(18S rDNA). Microplankton cells were collected at 30 locations in South China Sea, and were assigned to 21 known and 4 unidentified genera(2 uncultured fungi and 2 uncultured stramenopiles) with phylogenetic analysis in parallel to the morphological identification.

MEMBRANE POTENTIAL——A KEY PARAMETER OF AQUATIC MICROPLANKTON

Membrane potential is essential for the uptake of substance and physiological activityin cells; and is an indicator of cell viability and a criterion of aquatic environment. It is also applied toclassification of ecological populations. So membrane potential is a key parameter in studies on aquaticmicroplankton. It can be estimated by microelectrode, radioisotope method, spectro photomeny, flow cy-

Community Characteristics Analysis of Eukaryotic Microplankton via ITS Gene Metabarcoding Based on Environmental DNA in Lower Reaches of Qiantang River, China

Eukaryotic microplankton plays an important role in water biotic community and in maintaining the stability of water ecosystems. Environmental DNA metabarcoding provides the opportunity to integrate traditional and emerging approaches to discover more new species, and develop molecular biotic indices that can be more rapidly, frequently, and robustly used in water quality assessments. In order to examine assemblages of eukaryotic microplankton in lower reaches of Qiantang River, ITS gene metabarcoding technology based on environmental DNA was carried out. As a result, various species of phytoplankton, fungi and zooplankton were annotated on. More phylum, classes and specieses of eukaryotic phytoplankton and zooplankton were found after compared communities taxa based on metabarcoding with that obtained from morphological examination. Nevertheless, Chlorophyceae was the most common assemblage both identified by using these two methods, also Mesocyclops leuckarti and Acanthocyclops bicuspidatus were both found to be the dominant species of Cyclopoida in the river. Additionally, the reads proportions of phytoplankton and zooplankton at the three freshwater sampling sites (Tonglu, Fuyang and Wenyan) decreased as temperature drop. Meanwhile, twenty classes of fungi were annotated on, of which the community characteristic was first researched in the river. There were significant spatial differences in values of Chao1 index for eukaryotic microplankton. Cluster analysis and Non-metric multidimensional scaling ordination further confirmed that the community composition of eukaryotic microplankton at class level for Jiashao-September sample had the most dissimilarity with the others.

Concentrated and gastight sampling technique of deepsea microplankton

A new sampling method of deepsea microplankton with function of in-situ concentrated sampling and gastight sampling was proposed. In-situ concentrated sampling technique was realized as follows: a microplankton membrane was used as filtration membrane, and a deepsea pump was used to pump seawater; the microplankton was captured and the density of microplankton was increased when seawater flow through the filtration membrane. Gastight sampling technique was realized as follows: a precharged accumulator was used as pressure compensator. During the process of lifting the sampler, the accumulator compensated the pressure drop continuously. The laboratory experimental results show that with in-situ concentrated sampling technique, in-situ concentrated sampling can be realized and the maximum concentration ratio reaches up to 500. With pressure compensation technique based on accumulator, gastight sampling can be realized. When sampling at 6 km and the precharge pressure of accumulator is 18 MPa, pressure drop of the sample is less than 2% compared with its original pressure. Deepsea experiment (at 1.9 km) results show that the sampler can realize in-situ concentrated sampling and gastight sampling.

Siliceous microplankton fluxes and seasonal variations in the central South China Sea during 1993-1995: monsoon climate and ? Nino responses

Seasonal variations of radiolarian and diatom fluxes in the central South China Sea during 1993-1995 were overwhelmingly controlled by monsoon climate. Radiolarian and diatom increased obviously during the Northeast (from November to February) and Southwest (from June to September) monsoons and decreased during the periods between the monsoons. The change of circulation driven by the monsoons improved water exchange in the different areas that brought rich nutrient materials for the surface microplankton, thereby enhancing radiolarian and diatom fluxes. Variation of radiolarian flux coincided with organic carbon flux, surface primary and export productivities. High radiolarian flux corresponded to high surface primary productivity. Radiolarian and diatom fluxes raised abnormally during 1994-1995 could be attributed to the El Nino event during the period.

凡纳对虾淡化养殖虾池微型浮游生物群落及多样性

2 0 0 2年 8月 15～ 10月 8日 ,对广东省珠海市斗门凡纳对虾淡化养殖虾池进行调查 ,虾池平均养殖面积为 0 .37±0 .11hm2 ,水深 136± 8cm,虾苗放养密度 131± 37× 10 4尾 / hm2 ;调查期间虾池水温 2 4 .3～ 33.6℃ ,p H值 7.1～ 9.6 ,早期养殖盐度 2‰～ 3‰ ,中后期为 0 ,透明度中后期稳定在 2 0 cm左右。鉴定浮游植物 4 8属 96种 ,其中绿藻 4 5种 ,硅藻和裸藻各 9种 ,隐藻 2种 ,甲藻 4种。优势种有 10种 ,多为蓝藻 ,如螺旋藻 (Spirulina sp.)、弯形尖头藻 (Raphidiopsis curvata)、小颤藻(Oscillatoria tenuis)、假鱼腥藻 (Pseudoanabaena sp.)、针状蓝纤维藻 (Dactylococcopsis acicularis)及水华微囊藻 (Microcystisaeruginosa)等 ,优势种的优势度突出。常见种有 30种 ,主要是绿藻、硅藻、隐藻 ,少见种有 5 7种。优势种和常见种多为富营养化水体中的或耐污性的种类。虾池原生动物有 2 9种 ,其中肉足虫 3种 ,纤毛虫 2 6种 ,优势种为毛板壳虫 (Colepshirtus)、卵形前管虫 (Prorodon ovum)和旋急游虫 (Strombidium spiralis) ,主要是以藻类为食的 A类群 ,常见种有膜袋虫 (Cyclidium sp.)、小单环栉毛虫 (Didinium balbianitnanum)、瓶口虫 (L agynophrya acuminate)、圆筒状拟铃壳虫 (Tintinnopsis

太湖不同湖区真核微型浮游生物基因多样性的研究

用DGGE（denatured gradient gel electrophoresis）和构建18SrDNA克隆文库2种方法对太湖不同湖区的真核微型浮游生物（0.8-20μm）多样性及组成结构进行了研究.DGGE结果表明,不同湖区真核微型浮游生物的DGGE指纹图谱存在明显差异,其中营养水平较低的东太湖和贡湖DGGE条带数最多,分别为23和24,香农多样性指数分别为3.135和3.178,而营养水平较高的梅梁湾和五里湖最少,均为18,香农多样性指数为2.890,表明营养水平较低湖区的多样性高于营养水平较高的湖区.克隆测序结果表明太湖中真核微型浮游生物种类丰富,占优势的主要是一些鞭毛藻、异养鞭毛虫、纤毛虫和真菌,而营养水平不同的梅梁湾、湖心、东太湖中真核微型浮游生物组成明显不同.在营养水平较高的梅梁湾,28.6%的OUT（operational taxonomicunit）属于异养鞭毛虫,另外隐藻、金藻分别占22.9%和14.3%;在湖心,金藻的比例最大,占25.7%,另外比较多的是异养鞭毛虫和隐藻,分别为20.0%和14.3%;而营养水平较低的东太湖各类纤毛虫所占比份最大,为26.8%,异养鞭毛虫较少,仅占4.9%,另外真菌含量较高,占12.2%.

天津港临港工业区附近海域中小型浮游动物群落结构

为了解天津港临港工业区附近海域中小型浮游动物的现状,于2014年4月至11月对该海域进行了5个航次调查,用浅水Ⅱ型浮游生物网采集了浮游动物样品,分析了中小型浮游动物的种类组成、丰度变化、生物多样性及群落结构。本次调查共鉴定浮游动物29种,主要优势种为夜光虫、多毛类幼虫、双刺纺锤水蚤、异体住囊虫等;浮游动物的丰度为110.89～2236.90个/m3;中小型浮游动物的多样性指数、均匀度指数和丰富度指数变化分别为0.4764～1.5732、0.1949～0.6086和0.6709～0.9158。水质生物学评价指标显示,调查海域的水质处于中度重污染或严重污染水平。

武汉市喻家湖春季微型浮游生物调查及水质污染指示

通过对武汉市喻家湖进行了两次春季微型浮游生物采样,研究了22个样品的水温、pH值以及微型浮游生物的种类、群落组成、优势种和污生指数,以此来研究喻家湖水质污染状况。结果表明:共鉴定到微型浮游生物42属62种,得到了各采样点生物群落组成和优势种类;根据微型浮游生物的污染指示种类和污生指数,可以得出喻家湖整体呈污染状态,1、2、5号采样点为寡污带,3、4、6号采样点为β-中污带,7至9号采样点为α-中污带,10号采样点为多污带,其中3、4、6号采样点水体明显混浊,且在水样中观察到了螅状独缩虫、简简变虫、梨波豆虫、褶累枝虫等有机污水中的常见优势种类,说明这些采样点有机污染严重。最后,结合各采样点的生境探讨了喻家湖水质污染的原因。

胶州湾浮游生物群落NH_4^+-N的吸收与再生通量

通过4个季节(1991年11月—1992年7月)的现场实验观测,初步研究了胶州湾表层浮游生物群落的NH_4^+-N吸收、再生通量的有关问题。结果表明,NH_4^+-N吸收、再生通量的季节变化为:夏季>春、秋季>冬季;周日变化为:吸收通量在白天大于夜间,再生通量夜间大于白天;全年平均,吸收通量为0.073μ mol/(L·h),再生通量为0.053μ mol/(L·h),再生通量始终小于吸收通量;NH_4^+-N的周转时间最长为16.34d(冬季),最短为0.68d(夏季);吸收通量主要来自Picoplankton(占总量的46％—57％);NH_4^+-N吸收具有光依赖性,不同粒级的光依赖顺序为:Netplankton>Nanoplankton>Picoplankton。

海洋浮游生物氮吸收动力学及其粒级特征

于1991年秋－1992年夏在中国科学院生态网络站之一的胶州湾进行4个季节的现场实验，运用15N同位素示踪方法研究胶州湾浮游生物群落对两种主要氮源铵态氮（NH+4-N）和硝态氮（NO-3－N）的吸收动力学及其粒级特征。研究初步阐明自然浮游生物群落在不同季节、对不同氮源的吸收特性和受控机制，首次在群落水平上给出不同粒级浮游生物氮吸收特征的定量描述，从而为新生产力研究、生态系能流分配和生源要素生物地化循环研究提供重要参数。

厦门港浮游生物对可溶性活性磷(SRP)吸收动力学的研究

于１９９０年４个季节在厦门港进行对浮游生物（＜２００μｍ）对ＳＲＰ吸收动力学的现场实验．结果表明，ＳＲＰ吸收动力学４个季节都符合Ｍｉｃｈａｅｌｉｓ－Ｍｅｎｔｅｎ方程，最大吸收速率（Ｖｍａｘ）是夏＞春＞秋＞冬，分别是各季ＳＲＰ吸收速率的１．１０，２．３３，３．０９和３．５５倍；ＳＲＰ吸收半饱和常数（Ｋｓ）是夏＜秋＜冬＜春，分别是各季ＳＲＰ的１．２９，２．３０，２．１９和３．６９倍，与ＳＲＰ成负相关．初步阐明了自然浮游生物群落在不同季节对ＳＲＰ的吸收特性和生态适应机制；首次探讨了运用３２ＰＯ３－４同位素稀释技术研究营养盐吸收动力学的实验方法．

厦门港小型浮游生物对可溶性活性磷吸收和再生通量的季节变化

用３２ＰＯ４３－同位素稀释法测定了厦门港小型浮游生物（＜２００μｍ）对可溶性活性磷（ＳＲＰ的吸收和再生通量；并同时测定了现场的Ｃｈｌａ、初级生产力和各种形态磷．厦门港ＳＲＰ吸收和再生通量有明显的季节变化，夏季最大、冬季最小，且ＳＲＰ通量与生源要素呈现协变性；表层（０．５ｍ）ＳＲＰ通量与Ｃｈｌａ成较好的正相关，ＳＲＰ通量的变化与浮游植物的消长密切相关．全年平均表层ＳＲＰ再生能满足初级生产磷吸收的４３．３％；底层（１６ｍ）再生与吸收比远大于１，ＳＲＰ的再生对初级生产的调控具有重要作用．表层全年平均ＳＲＰ的周转时间为８８．７５ｈ，７月ＳＲＰ最低，但其周转时间也最短仅为３．７ｈ，以最大程度地利用磷维持较高的初级生产力．较低的碳、磷同化原子比及较短的ＳＲＰ周转时间表明厦门港磷同化速率较高．

旧金山湾卤虫在同安盐田实验池中种群动态的初步分析

美国旧金山湾卤虫于1989年引入同安盐田实验池养殖,1989年10月至1990年3月池内人工养殖卤虫的结果表明,秋、冬两季实验池的水温变化不是影响卤虫种群数量变动的主要原因,卤水盐度的变化对卤虫幼体群体数量有较大的影响,饵料是影响卤虫种群变动的主要因子,使用花生渣饼磨浆后投喂卤虫比使用干鸡粪更有利于卤虫种群的增长。实验证实旧金山湾卤虫能在同安盐田安全越冬.

厦门港小型浮游生物对可溶性活性磷的吸收和再生通量

应用32PO43-同位素稀释技术比较研究了厦门港3个站位4个季节表层（0．5m）浮游生物（＜200μm）对可溶性活性磷（SRP）吸收和再生通量。结果表明，SRP吸收和再生通量夏季（7月）最大，冬季（1月）最小；近河口的Ⅱ站SRP通量最大且季节波动性大，位于港口外缘的Ⅰ站SRP通量最小且季节波动小；各站SRP通量变化的差异与其不同的理化环境有关。文中还研究探讨了浮游生物在不同季节、不同站位对SRP吸收和再生通量的变化特性及生态适应机制。

渤海湾浮游生物氮吸收动力学研究

本文利用15N同位素示踪法，对渤海湾2个季节浮游生物氮吸收动力学进行了初步研究。结果表明，海洋浮游生物对氮营养盐的吸收动力学特性可由米门公式很好的描述。浮游生物对氮营养盐的吸收存在明显的季节变化，呈现夏季高，秋季低的特点，并且另外浮游生物对两种主要氮源—氨氮和硝酸盐氮的吸收存在明显的差异，浮游生物对硝酸盐比对氨氮吸收动力学参数的季节性变化较大。

英国北海盆地北部侏罗系微体浮游藻类组合带

研究基于英国北海盆地北部两个钻孔剖面的侏罗纪地层,发现大量的多样化的沟鞭藻及其它有机质藻类(统称为微体浮游藻类),描述了各组的微体浮游藻类组合,建立了10个沟鞭藻组合带,并与其它地区同时代地层中的沟鞭藻组合带进行了对比.

三门湾微型浮游生物丰度的时空变化特征

粒径小于20μm的微型浮游生物能迅速响应海洋环境变化,因而在海洋环境监测中起着重要作用。本文应用流式细胞技术研究了三门湾表层与底层海水中微型浮游生物(包括细菌、聚球藻、微型真核生物以及病毒)丰度的时空分布特征,探讨了微型浮游生物丰度与水体理化因子之间的关系。结果表明,三门湾海域微型浮游生物丰度范围:细菌,6.98×10~5~9.84×10!6 cells/mL;聚球藻,1.10×10~3~3.71×10~4 cells/mL;微型真核生物,1.04×10~3~3.75×10~4 cells/mL;病毒,1.01×10~6~3.47×10~7 mL^(-1)。夏、秋两季表层微型浮游生物丰度均高于底层;秋季细菌、聚球藻和病毒丰度低于夏季,但微型真核生物丰度高于夏季;温度是造成微型浮游生物丰度季节差异的主要因素。微型浮游生物丰度的水平分布在夏季无显著规律,但秋季表底层均由内湾向外湾递减。秋季,除底层的细菌外,微型浮游生物丰度水平分布与pH和盐度呈显著负相关,同时与亚硝氮、硝氮、铵氮、叶绿素a呈显著正相关。

珠江广州段浮游真核微生物分布及其法医学意义

通过对珠江水域(广州段)水样进行18S rDNA测序分析,探究同一水域不同地点的硅藻及其他浮游真核微生物的分布和差异,以期为溺死诊断和溺水地点的推断提供参考依据。在珠江水域(广州段)随机等距离选取4个取水点采集水样,采用18S rDNA测序对各取水点的硅藻及其他浮游真核微生物进行定性和定量分析。珠江不同取水点包括硅藻在内的浮游真核微生物的种类数量(OTU数)平均为483.73±39.06个,但不同取水点中的数量具有显著差异。同时,不同取水点的微型浮游生物组成比例也存在显著差异。取水点W1与W4中存在特异的硅藻属:W1为脆杆藻属;W4为圆筛藻属、细柱藻属和泥生藻属。种水平上的分析显示,所有取水点均具有特异物种,而以W4中为最多,达98种。珠江水域(广州段)不同地点的浮游真核微生物群落分布及其差异可为死因和溺水地点的推断提供参考,并可用于建立珠江水域的浮游真核微生物数据库。同时,珠江水域不同地点存在的特异物种,也可为溺水地点的推断提供新指向。