海水悬浮颗粒物中不同形态磷的测定

分别采用硫酸过硫酸钾作为氧化剂进行高压消解和用浓度为1 mol/dm³盐酸浸泡提取,然后用磷钼蓝分光光度法测定海水悬浮颗粒物、沉积物中的总磷和无机磷,用差减法得到有机磷。悬浮颗粒物总磷(PTP)和无机磷(PIP)质量浓度分别为(632.4～651.7)×10^-6和(436.6～452.6)×10^-6时,其相对标准偏差小于1.44%。悬浮颗粒物总磷、无机磷和有机磷的回收率分别为97.2%～101.3%,97.8%～100.4%和97.3%～102.3%。所建立的分析方法可用于海水、河口水悬浮颗粒物及沉积物中不同形态磷的测定。     

胶州湾东部海水中氮的含量和分布

根据 1990年 11月到 1991年 8月胶州湾东部 4个航次的调查资料 ,讨论了各种氮的含量变化及分布情况 :溶解无机氮含量范围为 1.12～ 34 .8μmol/ dm3,年平均为 11.1μmol/ dm3。秋季硝酸氮为溶解无机氮的主要形式 ,占 68% ,平均为 11.2 μmol/ dm3。其他 3个季节氨氮含量最高。冬、夏两季溶解态有机氮含量分别占总氮的 69%和 66% ,是主要形态。其分布大致呈自东北向西南递减变化。     

海口湾海水重金属的行为特征

本文对海口湾溶解态铜、铅、锌、镉进行了测定.铜的变化范围为:0.47～1.16μg/dm3,平均值为0.78μg/dm3;铅的变化范围为:0.94～2.36μg/dm3,平均值为1.36μg/dm3;锌的变化范围为:1.28～4.83μg/dm3,平均值为3.14μg/dm3;镉的变化范围为:0.005～0.072μg/dm3,平均值为0.030μg/dm3,Cu、Zn的溶解态含量在龙昆路生活污水排污沟口、秀英工业排污沟口及海甸溪口的测站相对较高,Pb、Cd溶解态含量较低,湾内各站平面分布较为均匀.它们的溶解态含量垂直变化趋势为:Cu、Pb、Zn底层大于表层,而Cd表层大于底层.对Cu、Pb、Zn、Cd的颗粒态含量也进行了测定,指出海口湾海水中的颗粒物对重金属的净化起一定作用.对铜的溶解态中的强络合态和不稳态铜也进行了研究,强络合态占总溶解态的比例均在85%以上,对生物起毒性作用有关的不稳态铜含量很低,均小于5nmol/dm3,表明目前海口湾海水中的重金属铜不会对生物生长产生影响.     

莱州湾海水中营养盐分布与富营养化的关系

根据2001年5月和9月2个航次莱州湾海区海水营养盐等的调查资料,分析了该海域海水中5项营养盐的分布特征及时空变化,评价了水质的富营养化状况。结果表明,溶解无机氮的平均浓度为9.80μmol/dm3,2个季节中溶解无机氮以NO3-N浓度为最高,平均为7.61μmol/dm3,占总无机氮的77.65%,是莱州湾海水中的无机氮主要形式;活性磷酸盐的平均浓度为0.48μmol/dm3,活性硅酸盐的平均浓度为11.31μmol/dm3。研究发现,莱州湾海水中溶解无机氮和活性磷酸盐浓度分别是12 a前的2.03倍和3.2倍。DIN∶P,Si∶P,Si∶DIN比值分别为69.5,34.2,1.4;因此,磷酸盐为限制因素。按照营养状态指数值,莱州湾海区湾顶近岸海域划分为富营养化区,秋季一旦水文气象等条件适宜有发生赤潮的可能。     

黄河下游营养盐浓度季节变化及其入海通量研究

2001年3月～2002年2月期间在黄河下游采集溶解及颗粒态营养盐样品,分析了黄河径流中各形态的营养盐的浓度及其月动态,估算此时段内黄河的营养盐入海通量。研究发现,溶解无机氮是溶解总氮的主要存在形式,硝酸盐是黄河中氮的最主要存在形态,其季节变化与水量变化趋势相反,年平均含量为(260.6±84.0)μmol/L,显著高于世界其它河流,为世界背景值(7.14μmol/L)的20多倍;黄河中磷主要以颗粒态存在,颗粒态磷含量变化规律与SPM的分布一致,其年平均含量为(16.2±22.9)μmol/L,磷酸盐含量较低,年平均含量为(0.42±0.20)μmol/L,与世界河流的平均水平相当。硅酸盐年平均含量为(122.0±18.2)μmol/L。每年约有17 200 t的总氮和1 600 t的总磷输入渤海,氮通量表现出在春季3月较高;磷通量在9月出现最高值,春季3,4月也较高;硅酸盐通量在3月出现最高值。     

桑沟湾海水中营养盐分布及潜在性富营养化分析

根据2003年8月—2004年7月桑沟湾海区12个航次海水营养盐的调查资料,分析了该海区海水营养盐的分布特征及时空变化,评价了水质的潜在性富营养化状况。结果表明,溶解无机氮的年平均浓度为10.15μmol/dm3。4个季节中溶解无机氮以NO3-N为主要存在形式,占年平均含量的78.69%,其中以秋季的含量为最高。NH3-N占无机氮年平均含量的15.11%,NO2-N占无机氮年平均含量的6.20%。活性磷酸盐的年平均浓度为0.23μmol/dm3,浓度呈现春季较低和秋季较高的分布特征。活性硅酸盐的年平均浓度为2.86μmol/dm3,浓度呈现冬季较低和夏季较高的分布特征。DIN∶P,Si∶DIN和Si∶P的比值年平均分别为43.2,0.31和13.4,磷酸盐和硅酸盐为限制因素。与1983年在该海域所获数据比较发现,溶解无机氮的浓度是20年前的10.7倍,活性磷酸盐的浓度较20年前降低了43.9%,活性硅酸盐的浓度较20年前降低了34.1%。桑沟湾海区营养水平仍很低,总体上处于贫营养或中度营养化阶段,海水水质质量较好。     

南海海域海水中各形态磷的化学分布特征

根据1998年7月和1999年1月两个航次的调查资料,对南海水体中磷的含量分布以及夏、冬季变化规律进行了探讨.结果表明,南海表层水体中磷酸盐夏季含量明显低于冬季,夏季平均含量为0.004μmol/dm3,而冬季为0.35 μmol/dm3;有机磷含量夏季高于冬季,含量分别为0.12,0.04 μmol/dm3;总磷含量的季节变化与无机磷酸盐类似,夏、冬季含量分别为0.22,0.61 μmol/dm3.在垂向分布上表层50 m水柱中PO₄3--P,总溶解态磷和总磷含量最小,随水深增加基本上呈线性快速增加,至500 m增加减缓,1 000 m左右为最大含量,然后随着水深略有下降.在夏季垂直分布比较典型,不同站位在一水深的含量离散性小,而冬季PO₄3--P,总溶解态磷和总磷的垂直分布则显得离散性大,尤其是PO₄3--P分布在200 m左右出现最大值,说明当年冬季南海各区域存在着较大水文、生物差异,很大的影响了化学环境的变化.在南海表层水中通常以有机磷占优势,在150 m深处以下的水中则以无机磷为主.深水中溶解的有机磷含量一般随水深减少.夏季的有机磷明显高于冬季,表明夏季的生物作用强烈.     

海水溶解色氨酸的荧光分析

本文初步建立了直接测定海水中溶解色氨酸的方法,并进行各种条件影响实验.在0～0.070mg/dm3浓度范围内色氨酸荧光强度与浓度之间线性关系良好.在最佳实验条件下,方法检测限为7.6×10-4mg/dm3,精密度小于3.1%,回收率86%～120%.     

2013 年夏秋季黄海溶解无机氮的分布及季节变化特征

依据2013 年夏季和秋季对黄海海域两个航次的调查结果,对该海域溶解无机氮的季节变化,垂直变化,平面分布状况及其影响因素进行了初步分析和探讨。结果表明,该海域溶解无机氮的分布及组成存在明显的季节性：秋季NO3-N的平均浓度为（7.09±4.15）μmol/dm3,远高于夏季（3.21±3.31） μmol/dm3;夏季NH4-N 含量（0.99±0.95）μmol/dm3 较秋季（0.79±0.82）μmol/dm3 高;夏、秋两个季节溶解无机氮的主要组成部分均为NO3-N,其比例约为70 %和90 %。受浮游植物生长、海水层化以及黄海冷水团存留的影响,调查海域夏季表层溶解无机氮的浓度较低,底层浓度较高;此外,研究海域表层溶解无机氮的分布明显受陆源输入控制,表层溶解无机氮的整体呈现出近岸高外海低的现象,NH4-N的高值区主要出现在靠近城市的近岸海区。该论文可以为该海域氮盐的海洋化学循环研究及赤潮等有害藻华的预防提供科学的理论依据。     

海水基质活性磷酸盐标准物质研制

本研究以西太平洋表层海水为基质,制备了浓度为0.5～4.0μmol/L的海水活性磷酸盐系列标准物质。通过对所研制的4批次样品进行均匀性、稳定性评估,确定样品性能良好。对基于磷钼蓝分光光度法的气泡间隔连续流动分析系统的反应和操作条件进行优化,优化后的方法检出限低至0.03μmol/L。不同浓度样品的相对标准偏差为0.37%～2.45%(n=9);通过与国际已有有证标准物质比对,本研究方法测量误差小于0.05μmol/L。经6家具有中国计量认证资质且具备海水磷酸盐检测能力的实验室联合定值,确定了该系列标准物质的标准值,并对定值结果的不确定度进行了分析评价,相对扩展不确定度为2%～10%。     

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.     

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.     

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.     

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.     

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

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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,