春季黄海微型浮游动物对不同粒径浮游植物的摄食速率研究

于2005年3月对黄海海域的7个站位应用稀释法研究了浮游植物的生长率和微型浮游动物对浮游植物的摄食压力。结果表明：实验期间,微型浮游动物生长速率范围在0．34～0．95d-1,浮游植物摄食速率范围在0．44～0．94d-1。微型浮游动物对浮游植物的现存量和初级生产力的摄食压力分别为47．76％～63．80％和61．50...     

海洋浮游细菌生长率和被摄食的研究综述

海洋浮游细菌利用海水中的溶解有机碳合成自身物质,是海洋浮游生态系统的二次生产者。微型浮游动物是细菌的主要摄食者,也是细菌生产向较高营养级传递的中介。研究海洋浮游细菌的生长率和被(微型浮游动物的)摄食率对理解海洋浮游生态系统的功能具有重要作用。本文综述了利用改变海水中生物类群组成(或功能)的培养方法研究海洋浮游细菌生长率和被摄食率的历程和现状,为我国的同类研究提供借鉴。改变海水中生物类群组成(或功能)进行培养的方法有海水分粒级培养、海水稀释培养和添加选择性抑制剂培养。这些方法各有其局限性,应用并不广泛。细菌及其主要摄食者异养鞭毛虫群落在自然海区和实验室内都有生长周期,鞭毛虫的生长周期落后于细菌,因此细菌的生长率有时会小于被摄食率,有时会大于被摄食率。我国这方面的研究相对落后,应值得引起重视,建议从海水稀释培养法入手开展相关研究。     

长江口几种优势桡足类对微型浮游动物的摄食研究

利用现场海水培养实验,结合浮游动物网样数据,研究长江口邻近海域几种优势桡足类(中华哲水蚤、背针胸刺水蚤、太平洋纺锤水蚤和精致真刺水蚤)对微型浮游动物的摄食影响。结果表明,精致真刺水蚤虽然属于肉食性种类,但几乎不摄食微型浮游动物;其余三种杂食性桡足类中华哲水蚤、背针胸刺水蚤和太平洋纺锤水蚤对微型浮游动物(纤毛虫+异养甲藻)的摄食率分别为0.66、0.09和0.59μg C/(ind·d),分别占其日总摄食量的29%、24%和37%。其中,异养甲藻在初始生物量和对桡足类饵料贡献上分别占整个微型浮游动物的30%和28%,是微型浮游动物中一个重要的组成类群。中华哲水蚤对微型浮游动物的摄食率与初始食物浓度有显著的正相关关系,并且对体长20μm纤毛虫的清滤率要明显高于对体长20μm的纤毛虫(P0.01)的清滤率,表明其偏好摄食较大个体的食物。通过Chesson选择性指数显示,尽管微型浮游动物在生物量上远小于浮游植物,但桡足类能优先选择摄食微型浮游动物;进一步结合网采浮游动物数据,获得各站三种优势桡足类丰度平均占桡足类总丰度的77%,但它们对微型浮游动物现存生物量的摄食压力仅为0.8%,表明桡足类对微型浮游动物群落的下行控制作用并不明显,仍有大部分微型浮游动物生物量未通过摄食途径进入到桡足类群落中。     

海蜇养殖港塭微型浮游动物的摄食和生产力研究

通过对山东省靖海湾海蜇养殖港塭定期采样,采用稀释法研究该海蜇养殖港塭水体中浮游植物的生长率、微型浮游动物对浮游植物的摄食率、摄食压力以及微型浮游动物的生产力。研究结果表明,海蜇养殖港塭微型浮游动物组成比较简单,海蜇养殖期间微型浮游动物丰度低于海蜇捕捞结束期。其中,海蜇养殖期间微型浮游动物的优势种为根状拟铃虫(Tintinnopsis radix),为600~2 600 ind/L,而海蜇捕捞结束后优势种为根状拟铃虫、诺氏麻铃虫(Leprotintinnus nordquisti)和运动类铃虫(Codonellopsis mobilis),丰度分别为3 000~6 000、1 500~3 0001、500~3 000 ind/L。研究期间,该港塭浮游植物生长率为0.05~1.03 d-1。微型浮游动物的摄食率为0.24~2.37 d-1,对浮游植物现存量的摄食压力为21.10%~90.61%,对潜在初级生产力的摄食压力为77.08%~583.68%,而微型浮游动物的次级生产力占初级生产力的22.92%~76.92%。本研究表明微型浮游动物在海蜇养殖港塭生态系统物质和能量流动中起着重要作用。     

台湾海峡南部夏季微型浮游动物对不同色素类群浮游植物的摄食压力

2005年7月在台湾海峡南部4个站位应用“稀释法”结合高效液相色谱(HPLC)色素分析技术研究了不同色素类群浮游植物的生长率及微型浮游动物对其的摄食死亡率.结果表明,不同色素类群浮游植物的生长率(k)和摄食死亡率(g)分别为0.52～ 1.34 d-1和0.25 ～ 1.10 d-1,微型浮游动物对不同色素类群浮游植物的现存量和初级生产力的摄食压力分别为22％～ 66％和40％～ 151％.通过比较不同类群浮游植物的g/k值,发现颗粒较大的浮游植物(硅藻和甲藻)的净生长率要大于那些微型藻类(蓝细菌、隐藻和定鞭金藻等)的净生长率,说明本次研究中微型藻类更易受到微型浮游动物的摄食控制.     

富营养河口水体藻华粒级结构的调控机制研究

为探究富营养河口水体藻华粒级结构的调控机制,本研究利用枯水期珠江口上游河水、下游海水及其等比例混合水进行培养实验,跟踪监测水体中叶绿素a和营养盐的浓度变化,并利用稀释实验估算藻类生长速率（μ）和小型浮游动物的摄食速率（m）,以阐明上行控制（营养盐刺激）和下行控制（摄食影响）对藻类粒级结构的影响。结果显示:营养加富能增加藻类的生物量,藻类群落的优势粒级由超微型和微型转换为小型;加富河水中μ维持2～3 d高值后下降,速率为（1.13±0.37）d?1,加富海水中μ逐步增加,速率为（1.06±0.16）d?1,加富混合水中μ轻微波动,速率为（0.58±0.14）d?1,总体上小型藻类μ最大。3组加富水体中m总体均先增大后下降,粒级差异不明显。藻类被小型浮游动物摄食率（m/μ）随粒级增大而减小,说明富营养刺激大粒级的生长,大粒级面临的被摄食压力较小。m/μ随藻类每日的比生长速率（μ_{Chl a}）降低而增加,说明藻华前期由上行控制主导,后期下行控制作用相对加强。本研究表明,富营养化不仅能够改变藻华的生物量,而且能影响其粒级结构,初步阐明了富营养河口水体中藻华粒级结构的调控机制。     

台湾海峡南部夏季微型浮游动物对浮游植物的摄食压力及其生产力

2004年7~8月在台湾海峡南部的5个站位,用稀释法研究了浮游植物的生长率,微型浮游动物对浮游植物的摄食率及其生产力.微型浮游动物主要为无壳纤毛虫,尤其是急游虫类和侠盗虫类.浮游植物的生长率为0.52~0.72/d,浮游动物的摄食率为0.45~1.33/d,相当于每天摄食浮游植物现存量的36%~74%和初级生产力的88%~141%.微型浮游动物的次级生产力(MP02)为初级生产力的28.5%~58.4%.表明微型浮游动物在台湾海峡夏季海洋生态系统的能量流动中发挥着重要的作用.     

亚热带和热带环境下夜光藻的摄食压力

2015年以广西三娘湾海域为亚热带海区,三亚海域为热带海区,利用稀释法开展了现场培养实验,测定热带和亚热带海区夜光藻对浮游植物、微型浮游动物对浮游植物的摄食压力,研究了夜光藻对不同粒径的浮游生物的摄食作用.结果表明:两个海区都有比较高的生长率和摄食率,其中细菌有最高的生长率和摄食死亡率;夜光藻的摄食率,从总浮游植物、微微型浮游植物到聚球藻、细菌逐渐增高.亚热带海区与热带海区相比,微型浮游动物的摄食压力更小,表明低温影响了浮游动物的摄食活性;而营养盐是引起亚热带海区高生长率的主要因素.     

冬季南海北部海域微型浮游动物及其对浮游植物摄食压力研究

2009年1月在南海北部海域的5个站位,采用稀释法和显微分析技术研究了浮游植物生长率及微型浮游动物对浮游植物的摄食压力,同时测定了微型浮游动物的丰度及类群组成.结果表明:南海北部微型浮游动物类群主要以无壳纤毛虫为主,南海北部微型浮游动物类群细胞丰度为33～529个/dm3.南海北部浮游植物生长率为0.45～1.83 d-1,微型浮游动物摄食率为0.44～1.76 d-1,摄食压力占浮游植物现存量的42.6%～82.8%,占初级生产力的97.3%～225.1%.近岸区摄食压力比陆架区高,表明冬季南海近岸区微型浮游动物摄食能够有效的控制浮游植物的生长,而陆架区浮游植物生长率大于摄食率,浮游植物存在着现存量的积累,微型浮游动物并不能完全控制浮游植物的生长.     

三亚湾珊瑚礁海区微型浮游动物种群组成和摄食研究

采用现场稀释法,以叶绿素 a 为检测对象,利用 2006 年 4 月的调查资料对三亚湾珊瑚礁海区微型浮游动物的种群组成和摄食情况进行了研究.结果表明,区内微型浮游动物的组成以纤毛虫为主.微型浮游动物以 Tintinnopsis compressa, Tintinnopsis cylindrical, Tintinnidium semicilidium 三种纤毛虫为优势种,其中 Tintinnopsis 属纤毛虫是优势种群,有 38 种,占总纤毛虫种数的37.3 %.微型浮游动物的摄食率 ( g ) 在 1.28 ～ 2.37 d-1之间,平均值为 0.945 d-1;浮游植物瞬时增长率 ( k ) 为 0.26 ～ 1.44 d-1,平均值为 1.963 d-1;微型浮游动物对浮游植物现存量和初级生产力的摄食压力分别在 72.20 % ～90.65 % 和 113.31 % ～ 315.34 %,平均值分别为 84.56 % 和 177.05 %.三亚湾珊瑚礁海区内,微型浮游动物的摄食水平主要取决于水体中微型浮游动物和叶绿素a之间的相对数量关系.在控制浮游植物生长和转移浮游植物生产力方面微型浮游动物起着相当重要的作用,可以在一定程度上降低潜在的富营养化威胁.     

A Review of Some Environmental Issues Affecting Marine Mining

This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested.     

Increased Particle Fluxes at the INDEX Site Attributable to Simulated Benthic Disturbance

Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement.     

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。     

Determination of In Situ Sediment Shear Strength from Advanced Piston Corer Pullout Forces

The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments.     

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.     

《Acta Oceanologica Sinica》Vol. 33(2014) contents

<正>~~     

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,