浙江省近岸海域底栖生物生态研究

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。     

南黄海大型底栖生物生态调查与研究

根据2008年9月第十二次中韩黄海环境联合调查底栖生物的调查资料整理而成,并与2006年的资料进行比较,分析研究了南黄海海域大型底栖动物的环境质量状况。结果表明,底栖生物种类组成以多毛类居首,软体动物次之。大型底栖生物的栖息密度、生物量和种类数基本上呈现沿岸高,黄海中部低的空间分布特征。调查海域东北部的B3站位是相对稳定的底栖生物栖息密度和生物量高值区。调查海域大型底栖生物可划分为7个群落,以临近长江口的群落Ⅶ的多样性指数和丰富度最高。靠近中国沿岸的群落的生物量组成与临近韩国的群落显著不同。中国与韩国的部分近岸海域均受到一定的人为扰动,但未发现有相互污染的情况。除群落Ⅳ和群落Ⅵ多样性指数和丰富度较低外,其它群落多样性指数和丰富度尚可,群落结构基本稳定。     

胶州湾海域大型底栖生物的调查与研究

根据2003年6月初对胶州湾海域的调查资料,分析了该海域的底栖生物的种类组成及生物量分布。共鉴定了40种底栖生物,平均总生物量为23.93g/m2,平均栖息密度为400个/m2。调查结果表明,生物量受盐度影响,而栖息密度受水深和有机质含量影响。胶州湾由于受污染缘故,多样性指数远低于3,生物群落呈非健康状态,并与20世纪90年代的调查结果相比较发现,生物量呈严重下降趋势,而栖息密度呈上升趋势。     

兴化湾大型底栖生物生态研究

兴化湾大型底栖生物已鉴定有314种,平均生物量为36.60g/m2,平均栖息密度为162个/m2.按Bray-Curtis相似性指数和多维排序尺度可划分为4个群落.应用丰度生物量比较法(ABC)和种类个体几何级数显示群落结构相对稳定.     

2009—2012年泉州湾大型底栖生物多样性研究

文章根据2009—2012年泉州湾4个航次的调查资料，对比分析了4年间大型底栖生物的种类数、生物量、栖息密度、生物多样性的变化趋势。结果表明：泉州湾大型底栖生物有103种，其中多毛类48种，软体动物25种，甲壳动物18种，棘皮动物6种和其他动物6种。多毛类、软体动物、甲壳动物占总种数的88.3%，三者构成大型底栖生物的主要类群。泉州湾大型底栖生物平均生物量为7.77 g/m2，平均栖息密度76个/m2；数量组成，生物量以甲壳动物居首位2.40 g/m2；栖息密度以多毛类占第一位38个/m2。泉州湾大型底栖生物种类数、生物量、栖息密度、生物多样性均为湾中部及湾外较好，湾顶较差；从2009—2012年际变化来看，生物种类数、平均生物量、平均栖息密度均为2009年最好，2012年相对较差，生物多样性年际变化不大，说明泉州湾的大型底栖生物环境受到了一定的影响。     

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

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.     

2016年夏季舟山近岸海域底栖生物调查与研究

底栖生物是海洋环境质量的重要指标。2016年夏季对舟山近岸海域37个站位的底栖生物进行调查，此次调查共鉴定出底栖生物45种，平均栖息密度为41 ind/m2，平均生物量为3.92 g/m2，底栖生物的栖息密度和生物量基本上由西向东逐渐升高。底栖生物的种类、密度、生物量、多样性指数与水深及水质中的盐度、pH、悬浮物、总磷、总氮呈弱或中等程度相关，与沉积物中重金属（铜、锌、铅、镉、铬、总汞）、砷、有机碳呈弱或中等程度的相关性，尤其与镉含量的相关性最为明显。由ABC曲线分析可知，该调查海域底栖生物受到一定程度的扰动。与2005年该海域调查结果比较表明，该海域底栖生物的多样性指数平均值较2005年略有降低，平均生物量较2005年降低，但平均密度较2005年升高。此次调查出现无底栖生物站位所占的比例较2005年上升。研究表明，2016年舟山海域海洋环境质量状况劣于2005年，应加强海洋环境监测与治理。     

石岛海域大型底栖生物群落特征

2008年8月~2009年5月分4个航次对石岛海域进行大型底栖生物调查,共发现大型底栖生物164种,整个调查海域内大型底栖生物的优势种明显;调查海域大型底栖生物平均密度和平均生物量分别为279个/m2和11.00 g/m2;调查海域大型底栖生物初步分为近岸的粗砂底质群落和离岸较远的泥沙底质群落。本调查结果与其他海域调查资料做了对比,并初步分析了与其他调查海域结果不同的原因。     

拟建宁海电厂附近潮间带底栖生物群落生态

2002年12月对拟建宁海电厂附近海域3条潮间带断面的底栖生物生态进行了调查,共鉴定出潮间带大型底栖生物71种,平均生物量为1753.92g/m2,平均栖息密度为839个/m2。生物多样性指数和K-优势曲线都显示了位于拟建电厂选址区内的潮间带底栖生物群落已经受到了扰动。     

2009年春季舟山海域大型底栖生物群落结构的生态特征

2009年4月对舟山海域13个站位的大型底栖生物群落结构的生态特征进行了调查,并结合2001—2008年浙江近岸海域生态环境监测数据资料,分析了该海域大型底栖生物的变化趋势及其生存环境现状。结果表明,调查海域共鉴定出大型底栖生物84种,其中多毛类31种,甲壳类25种,软体动物12种,鱼类8种,腔肠动物4种,棘皮动物和其它类各2种。2009年春季该海域大型底栖生物的生物量平均值为11.62g/m2,丰度平均值为208.5个/m2,生物多样性指数(H′)为1.64,丰度呈由近岸向外海递增的趋势。根据Bray-Curtis相似性系数聚类分析和多维尺度排序分析,该海域大型底栖生物可划分为3个群落,分别为群落Ⅰ:双鳃内卷齿蚕-织纹螺-孔鰕虎鱼群;群落Ⅱ:色斑角吻沙蚕-脊尾白虾群落;群落Ⅲ:葛氏长臂虾-织纹螺群。通过丰度/生物量累积k-优势度曲线分析可知,该海域大型底栖生物群落已受到中度程度的污染或扰动,群落结构不稳定。比较分析2001—2009年舟山海域大型底栖生物生物量和丰度变化趋势可知,个体较小、生长周期较短的种类逐步成为舟山海域的优势类群。     

Microbial Biomass and Organic Nutrients in the Deep-Sea Sediments of the Central Indian Ocean Basin

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.     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

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.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

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。     

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.     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

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.     

Flow Cytometric Analysis of Coastal Lagoon Bacterioplankton and Picophytoplankton: Fixation and Storage Effects

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.     

Deep-Sea Sediment Compression Curves: Some Controlling Factors, Spurious Overconsolidation, Predictions, and Geophysical Reproduction

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.     

INFORMATION FOR AUTHORS

<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,