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1.
By using the methods of qualitative and quantitative analysis, the species composition and dominant genus of harmful, ciliates in young abalone culture ponds are studied. Totally 68 species of ciliates, belonging to 3 classes, 16 orders and 46 genus, are found. The dominant ciliate species are Aspidisca leptaspis, Vorticella sp. and Euplotes rariseta. During the young abalone cultivation, the numbers of young abalones increase first,and then show a trend of decreasing. The relationship between the density and composition of ciliates and the density of algae in the young abalone culture ponds is also discussed. 相似文献
2.
Simulation of the seasonal thermal structure in the Bohai Sea 总被引：1，自引：0，他引：1
The seasonal thermal structure in the Bohai Sea are examined with a three-dimensional boroclinic primitive equation model for shelf sea.The evolution of the seasonal thermal stratification is well simulated.The stratification appears early in April,first in the area off Qinhuangdao and it is well developed in the middle of May.It intensifies with synoptic and neap-spring fluctuations throughout the summer and reaches its maximum in the middle of July.Eventually,it is destroyed at the end of September.There are cold water belts between well-mixed and stratified regions.They are loGated on the mixed side of tidal fronts,and coincide with the isolines for a temperature difference of 1-2℃ between surface and bottom.The sea surface temperature (SST) distribution shows local maxima at the head of three bays and to the south of Qinhuangdao during the summer.The Bohai Sea responds to the variability in the atmospheric forcing and in tides with the synoptic and neap-spring variations of SST,as well as in the stratification and in variable positions of tidal fronts. 相似文献
3.
Li Jinxia 《海洋学报(英文版)》1989,8(3):401-408
Isotope dilution mass spectrometry (IDMS) and ultra-clean room approach are successfully used in the determination of Cd, Pb and Zn in seawater and the sample pretreatment of analysis. The precision in the determination of Cd, Pb and Zn in seawater is better than±3% and the limits of detection are 6×10-12, 6×10-11 and 2.4×10-10 respectively. The effects of sample pretreatment such as filtration and acidification on the results of determination of Cd- Pb and Zn in seawater are disscussed. 相似文献
4.
The Tianjin Port is the largest man-made port in China.Since the navigation channel of the Tianjin Port is constructed by dredging,a very important problem,as many people concerned,is the submarine slope stability.As the environment on land is different from that in submarine,it is necessary to evaluate the influence of the environmental loading,such as wave and tide,on the stability of navigation channel slope.In the present study,based on the observed results,the characteristics of the navigation channel slope are summarized,and the causes of creating the special slope shape are analyzed.The roles of waves and tides are evaluated,and failure mechanics are discussed to helq us predict what will happen in the future. 相似文献
5.
Based on the traditional way of abalone breeding,the technological process of industrial abalone breeding suitable for the coastal areas of southern China has been developed.The process is simple and easy to handle,and results in a high yield of young abalones after being applied. 相似文献
6.
Experimental Study of A Pile-Restrained Floating Breakwater Constructed of Pontoon and Plates 总被引：3，自引：3，他引：0
A pile-restrained pontoon-plate floating breakwater is proposed in this paper.The laboratory physical-model tests are conducted to investigate the wave-dissipation property and heave-motion response of a model.The influence of the model′s geometric parameters including relative pontoon width,plate width,number of plates and pontoon draft on wave-dissipation performance and heave-motion response are discussed,as well as the correlation between these two factors.The result indicates that wave-dissipation performance of the proposed structure is better than the pontoon structure:its transmission coefficient and heave-motion height are reduced by 0.2 and 0.3,respectively,in comparison with those of the pile-restrained pontoon model at a relative pontoon width of 0.2. 相似文献
7.
The distributional features of sea surface temperature and salinity(SST and SSS) in the Taiwan Straits have been analyzed using the SST and SSS underway measurements in August,1999.The characteristics of SST and SSS are summarized as foloows:There are several upwellings and diluted water in the Taiwan Straits.The upwellings are divided into two kinds:those along the western coast of the Taiwan Straits and those around the Taiwan Shoal.There are three sources of diluted water:diluted water of the Jiulongjiang River,diluted water of the Zhujiang River and diluted water of the Minjiang River. 相似文献
8.
The concentration and partition ratio of various speciations of nutrients in domestic sewage were determined. The transformation and transportation among the speciations, as well as their biological effects during sewage-seawater mixing were simulated in laboratory. The results are compared with field observation and the following findings are: i) The suitable range of ratio DIN/DIP in seawater for growth of phytoplankton in subtropical estuary and harbor is quite wide. It could grow well even in the range of 15-55 in atom ratio, and is independ of the variation in levels of N and P. ii) The transformation rate among the speciations of phosphorus is within the range of 0. 5 to 1. 1 μmol/d . iii) Phytoplankton uptakes P prior to N during its growth. The growth rate for Skeletonema costatum (the major species) and field algae are 0. 34-0. 58/d and 0. 30-0. 31/d, respectively. iv) The red tide species Prorocentrum micans could become the dominant species to a density 107 cells/L after Skeletonema costatum 相似文献
9.
The geological-geophysical map series of the eastern China seas and adjacent region (1:1 000 000) will be published in the late half year of 2009. The regional tectonic map is one of the main professional maps. The Mapping methods, the division method of geological tectonic units and the main geological tectonic units are mainly discussed. The strata from Pliocene to Holocene are peeled off so as to display the Pre-Pliocene structures. In basins, isopaches are drawn for the Cenozoic deposits. The plate tectonic theory and present tectonic pattern are adopted as the priorities in tectonic division. As to the division of intraplate tectonic units, it is a revision, complement and improvement of previous dividing systems, and the nomenclature for each tectonic unit follows the current system in China. The first-order tectonic unit is plate (Pacific Plate, Eurasian Plate and Philippine Sea Plate). The second-order tectonic unit is tectonic domain (East Asian continental tectonic domain,East Asian continental margin tectonic domain and west Pacific tectonic domain). The Philippine Sea Plate and the west part of the Pacific Plate are called the West Pacific tectonic domain. The part of the Eurasian Plate involved in this study area can be further divided into East Asian continental tectonic domain and East Asian continental margin tectonic domain. The East Asian continental margin domain is composed of the Ryukyu island arc, the Okinawa Trough back-arc basin and the back-arc basin of Sea of Japan. The East Asian continental tectonic domain in this study area is composed of the Sino-Korea Massif, the Changjiang River (Yangtze) Massif and South China Massif. In turn, these massifs consist of basins, folded belts or uplift zones. The basins,the folded belts or the uplift zones are further divided into uplifts and depressions made up of sags and swells. 相似文献
10.
Intracytoplasmic infection with a prokaryotic mycoplasma-like organism (MLO) were characterized in the scallop Argopecten irradians, and the first report of such infection in this scallop was represented. Ultrastructurally these microorganisms are usually pleomorphic and variable in morphology and size, and appear in several cell types such as small spherical body, rod-shaped bodies and longer filament-shaped body. They lack a cell wall. These observations revealed that these types of the prokaryote showed some characteristics of a mycoplasma-like organism (MLO). MLO reproduced in two ways: binary fission and budding. The results of isolation and purification showed that a large number of MLOs existed in the tissues of diseased scallops. The results of experimental infection revealed that the MLO is pathogenic to the scallop Argopecten irradians. 相似文献
11.
A depth profile of bacterial community structure in one deep-sea sediment core of the western Pacific ＂warm pool＂ （WP） was investigated and compared with that in a sediment sample from the eastern Pacific （EP） by phylogenetic analysis of 16S rDNA fragments. Five bacterial 16S rDNA clone libraries were constructed, and 133 clones with different restriction fragment length polymorphism （RFLP） patterns were sequenced. A phylogenetic analysis of these sequences revealed that the bacterial diversity in a sample from the WP was more abundant than that in the EP sample. The bacterial population in the sediment core of WP was composed of eight major lineages of the domain bacteria. Among them the γ-Proteobacteria was the predominant and most diverse group in each section of WP sediment core, followed by the α-Proteobacteria. The genus Colwellia belonging to γ-Proteobacteria was predominant in this sample. The shift of bacterial communities among different sections of the WP sediment core was δ-, ε-Proteobacteria, and Cytopahga-Flexibacteria-Bacteroides （CFB） group. The ratios between them in the bacterial communities all showed inversely proportional to the depth of sediment. The sequences related to sulphate reducing bacteria （SRB） were detected in every section. The bacterial community structure in this sediment core might be related to the environmental characteristics of the surface seawater of the western Pacific WP. 相似文献
12.
The diversity of modular polyketide synthase (PKS) genes in sediments of Ardley Island in Antarctica, was studied by restriction fragment length polymorphism (RFLP) analysis. Phylogenetic analysis of 14 amino acid (AA) sequences indicates that the identified ketosynthase (KS) domains were clustered with those from diverse bacterial groups, including Cyanobacteria, γ-Proteobacteria, Actinobacteria, Firmicutes, and some unidentified microorganisms from marine sponge, bryozoan and other environmental samples. The obtained KS domains showed 43%-81% similarity at the AA level to reference sequences in GenBank. Six identified KS domains showed diverse sequences of the motif (VQTACSTS) that was used to identify the hybrid PKS/nonribosomal peptide synthetase (NRPS) enzyme complex, and formed a new branch. These results reveal a high diversity and novelty of PKS genes in antarctic sediments. 相似文献
13.
宁波北仑港冬季浮游细菌多样性研究 总被引：3，自引：0，他引：3
采用分子生物学方法对宁波北仑港冬季水体中的浮游细菌多样性进行了研究.提取水样中细菌基因组总DNA,以细菌16S rDNA通用引物进行PCR扩增,扩增产物经分子克隆、测序与序列分析,对水样中的细菌建立了16S rDNA克隆文库和系统发生树.结果表明,浮游细菌群落具有较高的多样性,34个克隆子分属2个不同的细菌类群,6个克隆子属于未知类群,优势细菌类群为Pro-teobacteria类群（变形菌类群）,占80%;细菌优势类群顺序为β-Proteobacteria类群（32.5%）、γ-Proteobacteria类群（25%）、α-Proteobacteria类群（15%）、ε-proteobacteria类群（7.5%）、Firmicutes类群（厚壁菌类群）（5%）.这一结果与近年来国内外有关港口微生物多样性的报道较为一致.用DNAStar中Clustalw程序从测序的40个克隆子中选出17个OTU进行系统发育分析,同样表明浮游细菌多样性较强. 相似文献
14.
辽河口沉积物中古菌和细菌群落结构分析 总被引：5，自引：1，他引：4
本研究旨在了解辽河口表层沉积物中古菌和细菌的群落结构组成、多样性及其与环境因子之间的相关性。采用构建古菌和细菌16S rRNA基因文库的方法，应用Illumina Miseq测序技术进行序列分析。结果表明:辽河口表层沉积物中细菌多样性高于古菌多样性，近岸细菌和古菌多样性高于远岸，即河相区（0.8~7.04）细菌多样性高于混合区（13.1~20.7）和海相区（24.2~31.5）；主要古菌群落为奇古菌门（Thaumarchaeota，72.73%）和广古菌门（Euryarchaeota，25.05%），其中泉古菌门（Crenarchaeota，0.001%）只在河相区站位被发现；细菌群落组成中变形菌门（Proteobacteria，61.94%）为该河口的优势菌群，其次为拟杆菌门（Bacteroidetes，11.21%）和酸杆菌门（Acidobacteria，5.59%），其他门类如蓝藻门（Cyanobacteria，3.03%）等比例较小。与环境因子的冗余度分析表明:影响表层沉积物中古菌群落分布的主要环境因子依次为氨盐、泥、酸碱度、盐度、电导率和砂，而细菌群落的分布主要受到溶氧、泥、砂、黏土和总磷的影响。由此可见，不同环境条件下微生物的群落结构存在空间异质性，不同微生物对同一环境条件的响应亦不同。 相似文献
15.
北极海洋沉积物细菌和古菌群落结构分析 总被引：2，自引：0，他引：2
This study was to investigate bacterial and archaeal community structure of pan-Arctic Ocean sediments by pyrosequencing.In total,investigation of three marine sediments revealed 15 002 bacterial and 4 362 archaeal operational taxonomic units(OTUs) at the 97% similarity level.Analysis of community structure indicated that these three samples had high bacterial and archaeal diversity.The most relatively abundant bacterial group in Samples CC1 and R05 was Proteobacteria,while Firmicutes was dominant in Sample BL03.Thaumarchaeota was the most relatively abundant archaeal phylum in Samples CC1 and R05,and the relative abundance of Thaumarchaeota was almost as high as that of Euryarchaeota in Sample BL03.These two phyla accounted for nearly 100% of the archaeal OTUs.δ-Proteobacteria and γ-Proteobacteria were the two most relatively abundant classes at Proteobacterial class level,and their relative abundance was more than 60% in Samples CC1 and R05.There were also differences in the top 10 relatively abundant bacterial and archaeal OTUs among the three samples at the 97% similarity,and only 12 core bacterial OTUs were detected.Overall,this study indicated that there were distinct microbial communities and many unique OTUs in these three samples. 相似文献
16.
海南红树林根系土壤中可培养细菌的多样性分析 总被引：3，自引：0，他引：3
为研究海南红树林根系土壤细菌多样性,充分发掘中国红树林特有微生物资源,作者于2012年12月份从10份采集于海南北港岛红树林根系淤泥样品中分离可培养海洋细菌,并基于16S rRNA基因序列分析的方法对样品中的细菌多样性进行研究。共分离得到122株海洋细菌,经并菌后选取其中的70株代表性菌株测序,结果发现它们分为4个类群:变形菌门(主要为γ-变形菌纲)(Proteobacteria)、拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)和放线菌门(Actinobacteria),分别占66%,19%,11%和4%。共代表30个属47个种,其中有9个潜在新种和2个潜在新属。本研究结果表明,北港岛红树林中存在着丰富的细菌多样性,很多类群可能是红树林特有细菌物种。 相似文献
17.
为研究海洋附着细菌的群落结构及动态变化,在厦门近岸海区进行挂板实验.将无菌玻璃板浸没于海水中,连续放置14 d.分别于放置1 h和7、14 d后取玻璃板上附着生物样品.用细菌通用引物构建16S rRNA基因克隆文库,每个克隆文库随机挑选约40个克隆子测序,序列同源性分析和系统进化分析结果表明,所有的克隆子可分为六大类群:γ-变形菌纲(γ-Proteobacteria)、拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)、α-变形菌纲(α-Proteobacteria)、蓝细菌门(Cyanobacteria)和真核硅藻类叶绿体,各类群分别占42.0%、4.5%、2.2%、2.2%、1.1%和45.0%.γ-变形菌纲变形斑沙雷氏菌(Serratia proteamaculans)为优势附着细菌,占测序克隆子的31.5%.这类细菌在1 h样品中的比例超过一半,说明变形斑沙雷氏菌在生物膜形成初期发挥着重要作用.随着挂板时间延长,检测到的细菌类群有所增加:附着7 d后检测到拟杆菌门细菌,附着14 d后检测到厚壁菌门细菌.γ-变形菌纲细菌所占比例随挂板时间的延长而逐渐降低,从挂板1 h的81%降至7 d的21%,14 d的18%.另外,在各阶段的附着样品中,都检测到较多的真核克隆子序列,约占16%～64%.本研究为进一步阐明海洋附着细菌的附着动态及其在生物膜形成过程中的作用奠定了基础. 相似文献
18.
为分析海洋微表层这一特殊生境中的细菌类群,于2010—2011年4个航次对北黄海微表层和次表层海水中的总菌丰度、可培养细菌丰度和群落结构进行了分析。采用流式细胞仪测定总菌丰度,平板计数法测定可培养细菌丰度,PCR-16SrDNA分析可培养细菌的群落结构。结果表明,调查海域微表层海水总菌均值为1.76×106 cell/mL,次表层海水总菌均值为1.07×106 cell/mL。可培养细菌丰度范围是1.00×102~1.70×106 CFU/mL,微表层和次表层可培养细菌所占总菌数量的百分比分别为13.05%和0.45%。微表层对总菌的富集因子(EF)均值为2.02,可培养细菌的EF均值为74.16。PCR-16SrDNA序列分析结果表明,该海域可培养细菌分属变形菌门(Proteobacteria)(94.34%)、厚壁菌门(Firmicutes)(1.89%)、拟杆菌门(Bacteroidetes)(1.89%)和放线菌门(Actinobacteria)(1.89%)4个类群。本研究初步发现,微表层对细菌具有较强的聚集作用,尤其对可培养细菌聚集作用更为明显。微表层中可培养细菌的群落结构与次表层有所不同,其种类丰富,来源和功能多样。由此可见,微表层独特的生境成就了其独特的微生物类群,其生态功能有待于进一步研究。 相似文献
19.
Bacteria, as the most abundant sediment organism, play a major role in the fate of pollutants. Therefore, many pollutant-related bacteria have been studied in harbor sediments, yet the entire bacterial profiles have not been reported. The bacterial diversity and community structures from sediments in Victoria Harbor (Hong Kong), including two polluted (VH and VHW) and two adjacent (open oceanic, TLC; estuary discharge affected, PC) sites, were characterized by analyses of four 16S rDNA clone libraries. Upon comparisons of RFLP patterns from 254 clones in the libraries, 178 unique phylotypes were retrieved. LIBSHUFF and Rarefaction analyses indicated that the sediment bacterial communities at the four sites showed high 16S rDNA richness and were significantly different from each other. Phylogenetic analysis of full-length 16S rDNA revealed 19 bacterial phyla in Victoria Harbor sediments. γ- and δ-proteobacteria, holophaga/acidobacteria, and planctomycetales were recorded in all the libraries. In addition, γ- and δ-proteobacteria were dominant at all sites (33.33–11.67%). Besides these two phyla, ε-proteobacteria, firmicutes, aminobacterium, holophaga/acidobacteria and bacteroidetes were judged to be major components of a given library since they constituted 10% or more of the total OTUs of the given library. The cyanobacteria, verrucomicrobia, β-proteobacteria, aminobacterium, chlorofiexi, and candidate division OP1, OP8 were detected in minor proportions in various libraries. A portion of the clones were only distantly related to sequences in the GenBank, suggesting bacteria in Victoria Harbor sediments were unique and diversified. 相似文献
20.
Microbial community respiration and structure of dead zone sediments of Omura Bay, Japan 总被引：1，自引：0，他引：1
Minoru Wada Shotaro Suzuki Tadashi Nara Yu Umezawa Motohiro Shimanaga Kazumi Matsuoka Hideaki Nakata 《Journal of Oceanography》2012,68(6):857-867
Monitoring sediment microbial community metabolism and structure is instrumental to understanding biogeochemical processes in and ecological impacts on bottom environments. The aim of this study was to determine potential community respiration and to reveal community dynamics of the microorganisms in the dead zone sediments of Omura Bay, Japan. The bay is highly enclosed and develops severe hypoxia in the central regions every summer. We collected sediment core samples from the center of the bay during hypoxia, estimated sediment oxygen consumption by using an adapted in vivo electron transport system activity (in vivo ETSA) assay, enumerated abundance of bacteria, and analyzed bacterial community structure by automated ribosomal intergenic spacer analysis. Higher ETSA and bacterial diversity were found in upper sediments (within 3?cm depth) from the center than the fringe of the bay. Sediment bacterial community structure of the bay center was distinct from that of the fringe. From these results, upper sediment in the dead zone of Omura Bay was characterized by (1) greater community respiration and (2) greater diversity of bacterial components compared with the non-hypoxic sediment of the bay fringe. These characteristics have important implications for understanding the interaction between microbial communities and the development of hypoxia in Omura Bay. 相似文献