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1.
2003年8月、12月,2004年2月、5月对茂名放鸡岛海域进行了浮游生物调查,分析了浮游植物物种组成、优势种及其细胞丰度分布和物种多样性.共鉴定出浮游植物36属57种(硅藻46种,甲藻11种),其中赤潮类生物22种.角毛藻属以及丹麦细柱藻、脆根管藻和尖刺伪菱形藻为全年主要优势种,在早春季节冰河拟星杆藻成为季节性优势种,5月份和8月份角毛藻属以及尖刺伪菱形藻和丹麦细柱藻的细胞丰度在放鸡岛周边局部水域超过107 m-3.放鸡岛海域浮游植物物种多样性指数和均匀度偏低,在合适的条件下,有可能形成硅藻赤潮. 相似文献
2.
胶州湾浮游植物群落结构及其变化的初步研究 总被引：22，自引：0，他引：22
利用2003年胶州湾调查资料，分析了浮游植物群落结构及其与温度和营养盐的相关性。结果表明，胶州湾浮游植物群落主要由硅藻和甲藻组成，生态类型为近岸广布种、温带种和暖温带种以及少数暖水种。浮游植物数量一年中出现2次高峰期，主高峰出现在9月，次高峰出现在2月，低值期在7月和10月至翌年1月期间。浮游植物数量较近几年继续降低，尤其是峰值。浮游植物在春季以角毛藻、丹麦细柱藻、中肋骨条藻和冰河拟星杆藻为优势种群，夏季至秋初暖水性近岸种中华齿状藻、泰晤式旋鞘藻和广温性种星脐圆筛藻占优势地位，而秋季至冬初羽纹硅藻和派格棍形藻逐渐占优势地位，并一直持续整个冬季。溶解无机氮、硅酸盐和磷酸盐与硅藻丰度无明显相关性（R^2〈0．1）。中心硅藻丰度与溶解态无机氮呈线性负相关（R^2=0．4399），而与硅酸盐和磷酸盐无明显相关性（R^2〈0．1）。群落多样性指数与中心硅藻丰度和硅酸盐呈线性相关（R^2=0．3198和0．4443）。 相似文献
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研究了辽宁东港鸭绿江口海域赤潮监控区6个测站的浮游植物种类组成、数量分布和群落结构特征.2011年5-10月浮游植物数量变化范围为9.80伊104~3.66伊108个/m3,浮游植物数量高峰出现在春季5月,最低值出现在夏季8月.共发现浮游植物4门33属70种,其中硅藻27属57种,甲藻4属11种,黄藻 1 属 1种,金藻 1 属 1种.优势种为尖刺拟菱形藻(Pseudo-nitzschia pungens)、中肋骨条藻(Skeletonema costatum)、窄隙角毛藻(Chaetoceros affinis)和夜光藻(Noctiluca scintillans),均为赤潮生物种.春季5月多样性指数和均匀度指数较低,但优势度指数较高,优势种是尖刺拟菱形藻,成为形成赤潮的潜在生物要素. 相似文献
4.
于2015-05(春季)、2015-08(夏季)对北至北隍城岛、南至蓬莱近岸的庙岛群岛海域进行网采浮游植物调查。样品共鉴定出67种浮游植物物种,其中硅藻60种,甲藻5种,甲藻孢囊1种,金藻1种。该海区春季浮游植物群落优势种为具槽帕拉藻(Paralia sulcata,优势度0.384)、刚毛根管藻(Rhizosolenia setigera,优势度0.319)、冰河拟星杆藻(Asterionellopsis glacialis,优势度0.054)、布氏双尾藻(Ditylum brightwellii,优势度0.021);夏季优势种为高齿状藻(Odontella regia,优势度0.787),庙岛海峡南部海区出现高齿状藻的密集分布区域。夏季浮游植物总丰度是春季的2.17倍。春、夏季浮游植物多样性指数和均匀度指数都较低,且其数量的时间、空间分布变化明显。春季,浮游植物细胞丰度、主要优势种数量、多样性指数、种类丰富度指数的空间分布特征为海区北部高,南部低;夏季与春季相反,为海区南部高,北部低。 相似文献
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2009年夏季乐清湾网采浮游植物群落结构特征 总被引：1，自引：0，他引：1
利用2009年8月(夏季)采集于乐清湾18个调查站位的浮游植物样品,对该海域浮游植物群落的种类组成、优势种及丰度分布、多样性和均匀度等群落结构特征进行了分析,结果表明:乐清湾海域鉴定出的浮游植物共65种,隶属于2门27属,其中硅藻门为23属57种,甲藻门为4属8种。硅藻门以圆筛藻属Coscinodiscus种类为最多,其次为角毛藻属Chaetoceros、根管藻属Rhizosolenia、菱形藻属Nitzschia、斜纹藻属Pleurosigma;甲藻门以角藻属Ceratium种类为最多,其次为多甲藻属Per-idinium。优势种均为硅藻,包括中肋骨条藻Skeletonema costatum、虹彩圆筛藻Coscinodiscus oculus-iridis、琼氏圆筛藻Coscinodiscus jonesianus和辐射圆筛藻Coscinodiscus radiatus,其中中肋骨条藻占绝对优势。浮游植物丰度分布不均匀,湾内部西岸、灵昆北堤附近和大门岛南部的浮游植物丰度较高,湾内部东岸和乐清湾向东海开口处的浮游植物丰度较低。乐清湾夏季浮游植物丰度的分布主要受硅藻丰度分布的影响,其中湾口向东海开口区域浮游植物丰度的分布受中肋骨条藻丰度分布的影响,湾内浮游植物丰度的分布主要受圆筛藻属丰度分布的影响;甲藻的丰度分布基本上不影响浮游植物丰度的水平分布格局。浮游植物多样性指数(H′)平均值为2.429,均匀度指数(J′)平均值为0.638,两指数均高于2008年夏季杭州湾水平,表明夏季乐清湾浮游植物群落结构组成优于杭州湾。 相似文献
6.
2013年春季崂山湾浮游植物群落及其环境控制 总被引：4，自引：0，他引：4
2013 年春季(3、4、5 月)对崂山湾海域浮游植物群落及其理化环境进行了3 个航次的调查研究。共鉴定浮游植物40 属75 种, 硅藻是调查区主要的浮游植物类群; 浮游植物细胞丰度平均为1.27×106个/m3,3 月份的平均丰度显著高于4、5 月份(P<0.01); 优势种主要为冰河拟星杆藻(Asterionopsis glacialis)、加拉星平藻(Asteroplanus karianus)、密联角毛藻(Chaetoceros densus)和夜光藻(Noctiluca scintillans), 浮游植物群落演替明显, 由3 月份硅藻控制逐步过渡到4、5 月份硅/甲藻共同控制; 相对较低的硝酸盐水平是导致4、5 月份浮游植物丰度显著低于3 月份的主要原因; 物种–环境数据的冗余分析(RDA)结果显示, 温度、硝酸盐含量是控制崂山湾春季浮游植物分布的重要环境因子。 相似文献
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2014年秋季渤海网采浮游植物群落结构 总被引：1，自引：0，他引：1
基于2014年秋季在渤海进行的水文、化学和生物方面的综合大面调查,研究了渤海网采浮游植物群落的结构特征,并结合文献资料,分析影响浮游植物群落结构形成的原因。结果显示:2014年渤海秋季共鉴定浮游植物3个门42属96种,其中以硅藻为主,为34属79种,占总物种的82%;甲藻门7属16种,占总物种的17%;金藻门1属1种。其中,角毛藻属的种类最多,共17种;其次为圆筛藻属,共13种。浮游植物总细胞丰度介于(0.71～72.15)×104 cells/m3,平均为13.88×104 cells/m3,硅藻与甲藻细胞丰度比值为2∶1,硅藻在莱州湾的细胞丰度极显著高于其他海区,甲藻在渤海中部海区的细胞丰度显著高于其他海区。浮游植物优势种主要为星脐圆筛藻(Coscinodiscus asteromphalus)、威氏圆筛藻(C. wailesii)、具槽帕拉藻(Paralia sulcata)、梭状角藻(Ceratium fusus)和夜光藻(Noctiluca scintillans)。渤海秋季浮游植物群落多样性水平分布不均,局部海域由于单一优势种过量繁殖多样性降低,低值区分布于辽东湾和渤海海峡海域。与历史同期资料对比,渤海海域浮游植物群落出现明显的物种演替现象,甲藻中的角藻逐渐兴起,其在渤海中部及辽东湾的优势地位已经超过角毛藻属和圆筛藻属,渤海秋季局部海区浮游植物群落结构已经由硅藻控制转为硅藻和甲藻共同控制。 相似文献
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2006年冬季北黄海网采浮游植物群落结构 总被引：6，自引：1，他引：5
根据2006年12月30日—至2007年1月17日北黄海的调查资料,对该海域浮游植物的种类组成、优势种、丰度及其分布和多样性等基本状况进行了分析。本次调查共鉴定浮游植物4门68属131种,主要以温带近岸和广布性种为主,其中硅藻有53属113种,占总种数的86.3%,甲藻有11属16种,占总种数的12.2%。浮游植物丰度平均值为88.89×104个/m3,硅藻丰度平均值为86.58×104个/m3,甲藻丰度平均值为2.28×104个/m3,硅藻丰度分布趋势决定了浮游植物丰度的分布趋势。辽宁南岸是浮游植物密集区,山东半岛北岸其次,而北黄海中部是浮游植物的稀疏区。优势种为:短角弯角藻(Eucampia zodiacus)、具槽帕拉藻(Paralia sulcata)、尖刺拟菱形藻(Pseu-do-nitzschia pungens)、密连角毛藻(Chaetoceros densus)、柔弱角毛藻(Chaetoceros debilis)、刚毛根管藻(Rhizosolenia setigera)。浮游植物群落Shannon-Weiner物种多样性指数平均值为1.80,Peilou均匀度指数平均值为0.42。与1959年1月相比,2007年1月北黄海浮游植物丰度由150.00×104个/m3降为88.89×104个/m3,下降了近41%,硅藻丰度由148.00×104个/m3降为86.58×104个/m3,而甲藻丰度由1.25×104个/m3上升为2.28×104个/m3,占浮游植物丰度的比例由0.8%上升为2.5%。主要优势种及优势属也发生了一定程度的变化,但浮游植物群落结构仍以硅藻为主、甲藻其次,浮游植物丰度总的分布格局变化不明显。 相似文献
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2005年夏末渤海网采浮游植物群落结构 总被引：1，自引：0，他引：1
利用2005年8月渤海4个断面共计42站位的综合外业调查所获资料,分析了浮游植物群落的结构特征.调查共鉴定出浮游植物5门48属114种,其中硅藻31属81种,甲藻13属29种,金藻1属1种,绿藻1属1种,裸藻1属1种(未鉴定到种),还包括1种分类地位不明确的三裂醉藻.渤海各近岸水域的浮游植物物种的分布具有较为明显的分散性,优势种多为硅藻,主要有中肋骨条藻、拟旋链角毛藻、菱形海线藻和旋链角毛藻;甲藻中叉角藻成为优势种.与历史资料比较发现主要优势种发生了演替现象.浮游植物细胞丰度值为5.4×104～23 843.8×104个/m3,平均为1 083.4×104 个/m3,与同期历史资料相比,细胞丰度值较往年偏高;各调查断面细胞丰度值大小依次为秦皇岛附近海域＞辽东湾＞黄河口附近海域＞渤海湾.香农-威纳指数为0.54 ~ 4.18,平均为2.60,渤海湾和秦皇岛附近海域处于较高的多样性水平,而黄河口附近海域次之,辽东湾最低.另外,网采浮游植物群落的多样性随细胞丰度值的对数增加而降低. 相似文献
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湛江港湾浮游植物的群落结构特征 总被引：2，自引：0，他引：2
2009年2月至11月对广东省湛江湾的浮游植物进行了周年的季节调查,结果共检出浮游植物97属311种(包括变种和变型)：春季178种、夏季142种、秋季117种、冬季92种,其中硅藻门54属209种,占总种类数的67.2%;甲藻门20属71种,占总种类数的22.8%;蓝藻门9属14种,占总种类数的4.5%;绿藻门9属11种,占总种类数的3.5%;金藻门2属2种,占总种类数的0.6%;裸藻门1属2种,占总种类数的0.6%;隐藻门1属1种,占总种类数的0.3%;针胞藻纲1属1种,占总种类数的0.3%。优势种共有19种：冬季7种、春季4种、夏季7种、秋季7种,全为硅藻,主要优势种为中肋骨条藻Skeletonema?costatum、旋链角毛藻Chaetoceros?Curvisetus、冰河拟星杆藻Asterionellopsis?glacialis、浮动弯角藻Eucampia?zoodiacus、丹麦细柱藻Leptocylingdrus?danicus和奇异菱形藻Nitzschia?paradoxa等,没有全年广布优势种,群落结构具有亚热带和沿岸性特征;4季均出现的种类共有33种,各季节间共有种类数在34—69种,Jaccard种类相似性指数范围在0.17—0.31,季节更替明显。多样性指数和均匀度平均值分别为3.02和0.43,群落结构较稳定;浮游植物细胞丰度在13.60×104?cells/L－67.33×104?cells/L之间,夏季最高,春季次之,冬季最低,属季节单峰型变化,与一般亚热带春、秋季出现丰度高峰不一致。浮游植物细胞丰度与叶绿素a和水温呈极显著的正相关,相关系数分别为0.633和0.418（P＜0.01,n=112,双尾）,与无机氮和活性硅酸盐呈极显著的负相关,相关系数分别为-0.493和-0.378（P＜0.01,n=112,双尾）,与其他环境因子不存在明显的相关性。 相似文献
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Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 相似文献
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海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。 相似文献
13.
Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification
An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm. 相似文献
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Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans 总被引：1，自引：0，他引：1
A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level. 相似文献
17.
Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations. 相似文献
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《海洋学报(英文版)》2014,(8):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
20.
Nabil Sultan Pierre Cochonat Jean Fran ois Bourillet Florence Cayocca 《Marine Georesources & Geotechnology》2001,19(2):107-133
This article presents a methodology developed to evaluate the instability of submarine slopes that extend over a large area. Special attention was paid to (1) the complex geometry (bathymetry) and the expanse of the slope, (2) the heterogeneity of the sediment, and (3) the distribution of the pore pressure. The safety factor was considered as a spatially varying quantity. The General Formulation (GLE, Fredlund and Krahn 1977), which fully satisfies equilibrium conditions, was used for evaluating the stability of the marine slope. The submarine slope failure, which occurred on 16 October 1979 during the construction of the new Nice airport, was studied in order to test the developed model. Geotechnical parameters were taken from experimental tests carried out by IFREMER on 19 cores extracted at different depths (from 27 m to 1300 m) (Cochonat, Bourillet, and Savoye, 1993; Mulder et al., 1994). Many scenarios were proposed in order to explain the cause of the Nice slope failure (Habib, 1994). In this article, two of those scenarios were tested. Simulation results are presented and discussed. 相似文献