黄河口表层沉积物污染现状及潜在生态污染风险评估（英文）

根据2006年到2007年,908专项黄河口附近海域表层沉积物的调查资料,研究黄河口海域表层沉积物中重金属含量分布特征;沉积物中Cu-Cd、Pb-Cr、Cr-As 3组元素间具有显著的相关性,表明它们分别具有相似的元素地球化学性质和来源;运用Hakanson潜在生态危害系数法对其潜在生态危害程度进行评估,黄河口沉积物的潜在生态风险的来源是镉和汞占据主要权重;运用生物效应浓度法对其生物毒性效应进行评价,结果表明,As对黄河口海域环境中生物的负面效应偶尔发生,Cu、Pb、Zn、Cd、Cr和Hg暂时不会产生不良生物效应。     

珠江口荷包岛近岸海域沉积物重金属分布及其潜在生态危害评价

本文采用2008年在珠江口荷包岛近岸海域的调查数据,对表层沉积物重金属的分布特征及重金属与TOC的相关性进行了分析,并采用Hakanson潜在生态危害指数法对其生态危害程度进行了评价。结果表明:重金属Cd,Hg,Cr和As四种元素分布基本呈现荷包岛近岸海域较高的特点,重金属Zn,Pb和Cu的分布没有明显规律;重金属富集顺序为Cd＞Zn＞Cu＞Hg＞As＞Cr＞Pb。相关性研究表明,重金属Cu与Zn显著相关,Hg,Cr,Cd和As极显著相关;有机质是影响沉积物重金属迁移和转化的重要因素。潜在生态危害评价结果表明,荷包岛近岸海域表层沉积物重金属总体潜在生态危害轻微;各重金属生态危害程度顺序为Cd＞Hg＞As＞Pb＞Cu＞Cr＞Zn;对荷包岛近岸海域生态环境具有潜在生态危害的重金属主要是Cd和Hg。     

山东近岸海域表层沉积物7种重金属污染特征和生态风险评估研究

本文综合运用单因子污染指数法、Hakanson潜在生态风险指数法和沉积物质量基准法3种方法,研究和评价了2012年和2013年山东近岸海域表层沉积物重金属的污染特征和潜在生态风险。结果表明:山东近岸海域94%以上站位的表层沉积物重金属含量符合第一类海洋沉积物质量标准,沉积物质量良好;山东近岸海域重金属综合潜在生态风险低,各重金属潜在生态风险由高到低为HgAsCdPbCuCrZn(2012年)和HgCdAsPbCuCrZn(2013年),Hg在个别站位达中潜在生态风险程度,为主要污染因子;50%以上站位As含量介于美国佛罗里达州和加拿大沉积物质量基准的TEL—PEL之间,表明负面生物效应偶尔发生。应加强对山东近岸海域表层沉积物中重金属Hg和As的监测,重点关注二者相对高值区的潜在生态风险和负面生物效应。     

威海双岛湾海域重金属的分布特征及生态风险评价

根据2012年双岛湾海域环境调查资料,研究了海水和表层沉积物中重金属的分布特征以及生态风险。结果显示,双岛湾海域海水中的重金属Cu和Pb在湾中部和湾底的部分站位含量较高,Zn和Cr含量在湾底最高、湾外最低,Cd和Hg在湾底和湾外的含量均高于湾中部,As的分布比较均匀;除Zn和Pb外,其余重金属含量均高于周边其他海域。双岛湾海域沉积物中重金属含量较低,与区域背景值相近,其中重金属Hg和Cd在湾内沉积作用明显,而Cu、Pb和Cr在湾外沉积作用比较明显。相关性分析表明,有机碳含量对双岛湾沉积物中的重金属分布影响不大。生态风险评价结果表明,双岛湾海域海水未受到重金属的污染;表层沉积物中重金属存在中低度的生态风险,具有潜在的不利生物毒性效应,重金属毒性大小依次为Pb>As>Cu>Hg>Cr=Cd>Zn。     

辽东湾表层沉积物的重金属污染特征与质量评价

本文研究了辽东湾表层沉积物中重金属的分布及污染特征,评价其生态风险及环境质量。对辽东湾表层沉积物8种重金属（As、Cu、Cd、Cr、Hg、Ni、Pb、Zn）的空间分布进行了研究,采用Hankanson法和I_geo（地累积指数）分析了该海域重金属潜在生态风险,并评价了该海域的环境质量。在辽东湾葫芦岛附近海域、西南部六股河口东南部海域以及西部近岸海域表层沉积物中As、Cu、Cd、Cr、Hg、Ni、Pb和Zn含量偏高。地累积指数法及生态风险指数法对重金属污染程度评价结果一致,辽东湾生态环境具有潜在危害的重金属主要是Cd、Hg和As,8种重金属潜在生态风险系数由高到低依次为Cd、Hg、Cu、Pb、As、Zn、Ni和Cr,各站位重金属综合潜在生态风险指数均大于150,生态风险总体上处于中等生态风险等级。Cd和Hg是该海域沉积物重金属中主要污染物,局部区域达到中、中-强污染程度。环境质量评价表明,辽东湾表层沉积物重金属引发有害生物效应的可能性不大,但Cd和Hg显著富集,应予以重视。     

天津海域沉积物重金属潜在生态风险危害评价

近岸海域环境质量是关系到海岸带地区可持续发展与人类健康的重要科学问题,根据 1997 - 2005 年监测资料,分析了天津海域表层沉积物中 6 种重金属的现状和变化趋势,采用地积累指数和 Hakanson 危害指数对天津海域沉积物重金属富集现状和对水生生物危害进行评估.结果显示:天津海域沉积物中 Hg , Cd , As , Cu , Zn 在所有站位均含量较低,Pb 含量较高.6 种重金属对天津海域生物潜在危害顺序为 Hg > Cd > Pb > As > Cu > Zn.     

北黄海表层沉积物中重金属含量及其污染评价

于2007年秋季对我国北黄海海域进行调查,采用原子吸收和原子荧光分光光度法对表层沉积物中的Cu,Pb,Zn,Cd,Hg,As进行了分析,并采用单因子指数法和Hakanson潜在生态危害指数法评价了该区域表层沉积物中重金属的污染程度和潜在生态危害。结果表明,北黄海表层沉积物Cu,Pb,Zn,Cd,Hg,As平均含量分别为(11.6±1.9),(25.2±2.4),(52.7±5.4),(0.22±0.02),(0.07±0.01),(13.3±1.3)μg/g;单因子指数法评价结果表明调查海域表层沉积物未受Cu,Pb,Zn,Cd,Hg污染,但部分站位As已处于中度污染水平;潜在生态危害指数法评价结果表明调查区域重金属元素的潜在危害程度顺序是HgCdAsPbCuZn,采样区域重金属的潜在生态危害轻微。     

同安湾表层沉积物重金属污染特征及潜在生态风险评价

对厦门同安湾表层沉积物7种重金属（Hg、Cd、Pb、As、Cu、Zn和Cr）、有机碳和硫化物含量进行了相关性分析和因子分析,并应用沉积物质量评价标准及潜在生态危害指数法对重金属的潜在生态风险进行了评价.结果表明：Cu、Pb、Zn、Cd、Cr、Hg、As含量范围和均值分别为6.49～46.20,16.95;6.68～46.90,23.93;45.4～162.0,87.4;0.028 9～0.402 0,0.147 6;8.50～33.20,15.95;0.013～0.117,0.047和1.5～6.8,4.8mg/kg.除As之外,各重金属含量之间有显著的相关性（相关系数为0.666～0.970）,且与有机碳含量的相关系数较高（相关系数为0.674～0.980）.重金属元素及有机碳与硫化物含量的相关系数较低.潜在生态风险评价显示：该海区沉积物中重金属生物毒性效应频繁发生的几率相对较小,生态危害程度也较低,尚属轻微生态危害.7种重金属潜在生物毒性风险大小依次为：Hg〉Cd〉Pb〉As〉Cu〉Zn〉Cr.     

苏北灌河口潮间带表层沉积物重金属空间分布特征及其环境效应

灌河是苏北地区最大、航运条件最好的入海河流。重金属元素分析显示,灌河口表层沉积物中Hg、As和Cu的含量高于背景值;Pb和Zn的含量接近背景值;Cd的含量低于背景值。其中Hg元素出现了中等程度的生态危害性,而Cr、As、Cu、Pb、Zn和Cd等元素的生态危害系数均极低,整个灌河口潮滩地区并没有出现较为严重的重金属生态危害。     

环渤海典型海湾沉积物重金属环境特征与污染评价

对渤海典型海湾近年来沉积物重金属数据分析的结果表明,Hg,Cu,Cd质量浓度的平均值均超过中国海域的平均值,其中Hg和Cd超标,高值区主要分布在锦州湾、大连湾附近海域,南堡镇和曹妃甸以南海域以及东营、莱州沿岸海域。地累积指数法的评价结果显示,沉积物重金属Cd污染属于轻度污染,其余重金属未发生污染。渤海典型海湾生态危害风险最大的重金属元素为Cd,Hg次之,其余Pb,Cu,As,Cr,Zn这5种重金属均为低生态危害等级。辽东湾海域重金属生态危害风险的顺序为CdHgPbAsCuZnCr;渤海湾海域重金属生态危害风险的顺序为CdHgPbCuAsCrZn;莱州湾重金属生态危害风险的顺序为CdHgPbAsCuCrZn。目前辽东湾沉积物重金属总潜在生态危害程度相对严重,主要分布在长兴岛、秦皇岛至锦州湾沿岸;莱州湾重金属生态危害程度一般,潍坊沿岸部分地区总潜在生态危害程度相对较高;渤海湾重金属污染生态危害程度相对较轻。     

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.     

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.     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

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.     

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,     

Evaluation of the Risk of Marine Slope Instability: A Pseudo-3D Approach for Application to Large Areas

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.