深海原生动物多样性研究进展

<正>1引言原生动物是一大类单细胞真核生物的统称,其中自由生活的主要类群包括异养鞭毛虫、纤毛虫和肉足虫(有孔虫和放射虫为代表);它们是生物圈中数量最为庞大的吞噬营养类群,部分种类具有内共生藻类或功能性叶绿体而进行兼性营养。在水环境中,不论是浮游或是底栖生活的原生动物,其生命过程与水体和底质的环境存在着密切的联系;并且通过各种营养关系与其他生物共同联结成为一个有机整体。同时,原生动物的基础研究也为探索真核生     

重金属离子对原生动物呼吸功能影响的研究

呼吸速率是动物代谢生理中的一个重要指标。研究生态系统中的能量转移、生物群落的功能和结构、环境对动物生命活动的影响等,都要进行耗氧量的测定。如浮游动物的呼吸速率与天然栖息处迁移的关系,浮游动物中桡足类(Copepoda)的呼吸速率与年龄以及区域和季节变异的关系,哲水溞(Diaptomus)在不同温度时的呼吸作用,原生动物的不同个体大小、重量和耗氧量的关系等等。此外,还有不少学者进行了污染水体中有毒物质对微小水生动物致毒作用的研究,如重金属离子对原生动物半致死浓度的测定,其目的是用它作为指示生物。在污染水体和污水的生物处理过程中,都有原生     

胶州湾浮游原生生物时空分布特征——丰度周年变化及与环境因子间的关系

为了解胶州湾浮游原生生物时空分布特征及与环境因子间的关系,自2007年6月～2008年5月,对青岛胶州湾内5个站点表层水的浮游原生生物丰度及环境因子进行了累计24次的周年采样调查及定性、定量分析.结果显示:(1) 浮游原生生物周年变动具有2个高峰,分别出现在4月和8月;(2) 浮游硅藻、鞭毛藻和纤毛虫的丰度周年变动均为双峰型:春节(4月)高峰、秋节(8月)高峰;(3) 浮游原生生物丰度与叶绿素a和溶解氧呈显著性相关,而其群落结构的变化与盐度、溶解氧、硝态氮和亚硝态氮的组合呈显著性相关.本工作为进一步探讨富营养化的内湾型近岸水体内原生生物生态学结构与功能提供了一份必要的基础资讯.     

赤潮期间藻类的化感效应

海洋环境条件的变化导致浮游生物(微藻、原生动物或细菌)暴发性增殖或高度聚集使局部水体改变颜色产生赤潮.海洋浮游微藻是引发赤潮的主要生物,在4 000多种浮游微藻中有260多种能形成赤潮,中国沿海的赤潮生物有148种,其中43种曾引发过赤潮.     

青岛近海物理-生物地球化学过程及其生态响应

近些年来,夏季黄海浒苔大规模暴发,并在青岛近岸海域大面积聚集,引起了广泛的关注。本文基于在夏季和冬季所获得的多学科调查资料,重点研究了青岛近海的水文-生物地球化学过程及其生态影响,阐明了该海域物理-化学-生物等多参数之间的耦合响应。研究显示,夏季黄海冷水团的边界可扩展至青岛近岸海域,并在局部涌升至上层水体,形成沿岸上升流;该上升流可对上层营养盐产生一定的补充,进而促进浮游植物的繁殖,并于底层海域对应形成溶解氧（DO）和pH的低值。夏季青岛近海的上升流可能还有利于随南风漂移至此的浒苔的生长,并在一定程度上引起浒苔的局地旺发;同时,夏季该海域特定的锋面系统对浒苔聚集的影响也不容忽视。冬季黄海暖流在苏北浅滩外侧向山东半岛南部海域延伸,扩展至青岛近海的暖水舌与近岸低温水之间的锋面特征明显,而且在向岸暖水与近岸冷水间还对应形成了明显的营养盐和叶绿素（Chl-a）锋面。该项研究从多学科交叉的视角,增进了对青岛近海物理、化学和生物过程之间耦合关系的认识。     

杭州西湖治理后的浮游动物现状

作者等曾于1978—1980年在西湖进行过治理前浮游动物的调查研究。从1981年开始,有关部门对污染严重的西湖水体进行了全面的综合治理。其主要措施有:整修湖岸,制止陆地的污物、尘土随雨水流入湖中;截污、环湖埋设近10公里的污水截流管道,使沿湖的生产和生活污水不再排入西湖;疏浚、清除湖底污泥五万立方米,增大蓄水量两倍多;打捞湖面废弃物,平均每天打捞废弃物200余公斤,减少了污物的沉积;改用直流电机游船,代替柴油机动游船,防止油垢污染;引流,从钱塘江引2000万吨清水入湖。由于采取上述治理措施,特别是引流的结果,近年来已逐渐降低了西湖水体的富营养化程度。治理后,西湖浮游动物有何变化,亦是各方关注的一个问题。为此,作者于1984年1—12月再度进行了西湖浮游动物的调查。按钱塘江水流入湖后的水路方向,布设了四个采样点,即小南湖和西里湖点(进水区)、湖中心点(敞水区)和少年宫点(出水区)。     

蚌、鱼养殖模式对水体富营养化控制作用的研究

为了探索控制水体富营养化的新方法．在5～9月长江中下游地区水体富营养的发展期，通过野外规模性试验，即水体吊养珍珠蚌并搭养少量鱼类，然后定期测定4个主要富营养化指标，观察水生生物种群和数量。结果表明，养蚌育珠并搭养适量鱼类可以使20～40cm的水层形成附着丝状藻类、原生动物、腔肠动物、多孔动物和苔藓动物等多种附着生物，使N，P，COD和BOD5含量分别下降67．3％，73．2％，38．1％和15．5％，起到了明显控制富营养化的作用，同时还能收获珍珠、蚌肉和贝壳等产品。比其他控制方法具有更好的实际应用性。     

合作发展海洋生物高新技术——访出席中日藻类基因工程及生物反应器学术讨论会的科学家

目前,由中国科学院海洋研究所实验海洋生物学开放研究实验室、中国海洋湖沼学会与日本通商产业省工业技术院大阪国立研究所、日本贸易振兴会共同在青岛举办的“中日藻类基因工程及生物反应器学术讨论会”,吸引了中日30余家高校和科研单位的110余名专家学者与会。 会间笔者采访了出席中日藻类基因工程及生物反应器学术讨论会的中日有关科学家。     

沙子口湾及其邻近水域定置网渔业生物多样性的研究

根据2006年5月～2007年5月逐月采集青岛沙子口近海作业的定置网具渔获物的分析与测定,记述了该海区出现的98种渔业生物,并进行了定置网渔获物组成的分析,分析了种类组成特点及生物多样性的季节变化情况.结果表明,本调查区域渔获物以小型低值鱼类、经济无脊椎动物和经济幼鱼为主,渔获个体偏小.据此提出了保护近海生物多样性与合理利用近海渔业资源的一些建议.     

西湖水域初级生产力和富营养化的调查研究

1985年2月至1986年2月,对杭州西湖水域微生物现存量和初级生产力进行了逐月调查研究。结果表明,用细胞数和叶绿素a所表征的浮游藻类的生物量,用ATP所表征的活生物碳量及用测氧法和~(14)C同位素示踪法所测得的光合作用速率均为岳湖>西里湖>小南湖>外西湖>北里湖>>三潭内湖。文章评价了近几年对西湖治理的效果,即富营养化的发展得到一定控制,但目前仍属于重富养化生态系统。文章还提出了导致富营养化的关键营养元素之一磷与光合作用速率、透明度等的定量关系,并通过西湖的年初级生产量(5334.2吨有机碳)换算出年潜在鱼产最(约50万公斤)。文章指出,放养摄食浮游藻类的鱼类是减轻湖泊营养负荷的重要途径之一。     

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,     

Estimation of Sediment Properties during Benthic Impact Experiments

Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges.