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2012年对围海造地后的福宁湾特殊生境海区开展春季、夏季两季的生态调查,研究底栖生物群落生态现状。两航次调查共鉴定底栖动物57种,其中软体动物24种,多毛类19种,甲壳动物9种等。总栖息密度407.5个/m2,其中软体动物占有65.6％的明显优势;总生物量为338.44g/m2,其中软体动物占有98%的绝对优势。种类数、生物密度和生物量三项指标,均为春季显著高于夏季,堤内高于堤外;聚类分析表明,季节是影响群落时空变化的主要因子;堤内外群落的差异主要与沉积物类型密切相关。 相似文献
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浙江省近岸海域底栖生物生态研究 总被引：6，自引：1，他引：5
对2003年4~5月在浙江省近岸海域底栖生物调查中获得的126种底栖生物的种类组成、生物量及栖息密度的分布和群落结构进行了叙述和讨论。结果表明:底栖生物种类组成以甲壳动物及软体动物占优势,两者占生物总种数的51.6%;浙江近岸海域底栖生物总平均生物量为18.74 g/m2;总平均栖息密度为89.1个/m2。按生态特征划分,调查海域的底栖生物可分成7个群落。分析调查海域各测站群落结构指数可以看出,浙江近岸海域70%测站呈现出生物多样性指数低及种类分布不均匀等特点。 相似文献
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胶州湾大型底栖甲壳动物数量动态变化 总被引：6，自引：0，他引：6
采用大型底栖生物调查研究方法,根据2000年2月-2002午11月共11个季度月在胶州湾10个站的综合调查资料,分析了胶州湾大型底栖甲壳动物的种类、生物量和栖息密度,并与1991年的调查结果进行了比较。结果表明,甲壳动物在胶州湾大型底栖生物中是仅次于多毛类的类群,本次调查共得到了大型底栖甲壳动物75种,其中端足类32种,占整个甲壳动物种数的42．1％;获得的甲壳动物平均栖息密度为39个／m^2,平均生物量为2．4g／m^2,均超过了1991年调查结果,这可能与近年来对胶州湾生物资源实施有效保护有关。胶州湾甲壳动物的数量分布与温度关系不明显,但盐度和初级生产力对其生物量和栖息密度影响较大。 相似文献
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大亚湾红树林区底相大型动物的群落 总被引：6，自引：2，他引：6
本文据1987～1989年实地调查资料,研究了大亚湾红树林区底栖生物的种类组成与数量分布。结果表明,分布于湾顶5种红树林内的底栖生物70种,主要由多毛类(23种)、软体动物(23种)、甲壳动物(12种)和星虫动物(8种)组成;平均生物量219.77g/m~2,平均栖息密度281个/m~2;在数量上以软体动物的腹足类占优势。文中应用群落结构指数进行分析,并与九龙江口的作了比较。 相似文献
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福清核电站邻近潮间带大型底栖生物数量分布与群落结构 总被引：3，自引：0，他引：3
于2006年2、4、7和10月在福清核电厂运行前对其邻近潮间带不同底质断面的大型底栖生物进行采样,以了解该潮间带大型底栖生物的种类及资源分布.结果表明,该核电站附近潮间带大型底栖生物总共为146种,以多毛类、软体动物和甲壳动物为主.以季节和底质为因素对取样获得物种数进行双因素方差分析显示:种类获得数的季节变化无显著差异,底质间呈边缘性显著.4季的大型底栖生物平均生物量为1 446.11 g/m2、平均栖息密度为972个/m2.大型底栖生物生物量平均值为春季＞夏季＞冬季＞秋季,栖息密度平均值为夏季＞春季＞冬季＞秋季.以季节和底质为因素的双因素方差分析显示:大型底栖生物生物量和栖息密度季节间无显著差异但底质间差异极显著.底质和季节间大型底栖动物的Shannon-Weiner指数、Margalef种类丰度、Pielou均匀度和Simpson优势度指数均无显著差异.利用Bray-Curtis相似性聚类对福清核电站邻近潮间带大型底栖生物进行分析后得出,该潮间带大型底栖生物可划分为两个群落:岩礁群落和泥沙滩群落.分析表明,底质是影响大型底栖生物分布的主要环境因子,季节对大型底栖生物分布的影响不显著. 相似文献
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山东半岛镆铘岛潮间带大型底栖动物群落特征 总被引：2，自引：2，他引：0
于2007年1月至2007年10月间冬、春、夏、秋4个季度月,对位于山东荣成的镆铘岛潮间带的高潮带、中潮带和低潮带进行大型底栖动物生态调查,根据所获得的样品,对该潮间带不同潮区大型底栖动物的种类组成、平均密度、平均生物量及物种多样性进行了分析.本次调查共采到大型底栖动物92种,其中多毛类环节动物11科22种,软体动物17科28种,甲壳动物18科33种,棘皮动物2科2种,扁形动物1种,腔肠动物2种,鱼类3种;平均栖息密度为329.67个/m2,软体动物贡献最大,其次为甲壳动物;平均生物量为81.74 g/m2,软体动物贡献最大,其次为多毛类环节动物.镆铘岛潮间带多样性指数H'垂直变化规律为高潮带>中潮带>低潮带,季节变化规律为秋季>春季>冬季>夏季. 相似文献
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渤、黄海近岸海域底栖生物生态研究 总被引：3，自引：0，他引：3
对渤、黄海近岸海域底栖生物的种类组成、生物量及栖息密度的分布和群落结构进行了叙述和讨论。结果表明 :渤、黄海近岸海域共获底栖生物 2 39种 ,种类组成以甲壳动物及软体动物占优势 ,为 51 .9% ;底栖生物平均生物量为 56.54g/m2 ,生物量组成以棘皮动物占绝对优势 ,为 41 .6% ;平均栖息密度为 2 64.3个 /m2。按生态特征调查海域的底栖生物可分成 7个群落。分析各测站群落结构指数 ,渤、黄海近岸海域 50 %测站表现出多样性及种类丰度高、种类分布均匀、优势度不明显的特点 相似文献
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珠江口东南部海域大型底栖生物群落特征研究 总被引：4，自引：0，他引：4
根据2006年的3月和7月在珠江口东南部海域进行的大型底栖生物调查,初步鉴定出大型底栖生物共156种,其中多毛类种类最多(79种),其次是甲壳动物(37种)。7月(116种)比3月(92种)种类多。3月大型底栖生物平均生物量和平均密度分别为6.703g/m2和679.4ind/m2,7月分别为22.436g/m2和576.3ind/m2。大型底栖生物种类数、生物量、密度和多样性指数(H’和J’)在调查海区东南部相对较低。采用Bray-Curtis相似性系数聚类分析和多维排序尺度(MDS)分析了3月和7月大型底栖生物群落的相似性,认为相同季节各站大型底栖生物相似性系数较高,大型底栖生物群落季节性差异相对较大。大型底栖生物群落在40%相似性以上,3月和7月分别可以划分出2个和3个生物群落。3月大型底栖生物群落Ⅱ和7月群落Ⅰ受到中等程度的扰动,其它生物群落处于轻微扰动状态。大型底栖生物种类数、密度、种类均匀度和种类丰富度与水深和沉积物特征相关性显著。 相似文献
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2014年9月和2015年5月,分别在泉州湾北岸布设3条潮间带断面进行大型底栖生物群落研究.共计采获潮间带大型底栖生物样品166种,其中泥沙滩有80种,岩相有96种.其中环节动物、软体动物和节肢动物有145种,构成该区域潮间带大型底栖生物的主要类群,调查的3条断面中,泥沙滩断面的平均栖息密度和生物量分别为133 ind./m~2和24.48 g/m~2,岩相断面的平均栖息密度和生物量分别为1 412 ind./m~2和958.78 g/m~2.数量垂直分布,泥沙滩断面和岩相断面平均栖息密度和生物量均以中潮区低潮区高潮区.数量季节变化,泥沙滩断面平均栖息密度和生物量均为春季(170 ind./m~2和32.04 g/m~2)大于秋季(96 ind./m~2和16.92g/m~2),岩相断面平均栖息密度为春季(1 360 ind./m~2)小于秋季(1 464 ind./m~2),而平均生物量为春季(1 122.83 g/m~2)大于秋季(794.75 g/m~2),数量季节变化显著.丰度/生物量曲线显示,泉州湾北岸潮间带大型底栖生物群落群落结构较为稳定,受到干扰较小. 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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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 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
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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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Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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《海洋学报(英文版)》2014,(9):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
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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