太湖大气氮、磷营养元素干湿沉降率研究

分析了2002年7月—2003年6月太湖周边地区太湖站、拖山岛、东山站、无锡、苏州、湖州、常州、金坛等8个站、点大气TN、TP沉降通量和降水化学组成观测资料,测定和计算了水气界面TN、TP的表观总沉降率(RT)、湿沉降率(RW)和干沉降率(RD)。太湖大气TN的年平均RT为4226kg/(km2.a),TP的年平均RT为306kg/(km2.a)。大气TN、TP的年沉降负荷分别占由环湖河道等点污染源输入的N、P总负荷的48.8%和46.2%。指出形成太湖大气TN污染的主要途径是湿沉降,而大气TP污染则主要来自气溶胶等固体物质的干沉降;小雨携带入湖的大气TN、TP污染物通量高于中雨和大雨。TN总沉降率曲线在春季3—5月出现高峰值的现象对太湖水体的富营养化具有潜在的促进影响。     

山东半岛南部近海大气气溶胶水溶性离子的化学组成

为研究陆源输入对中国近海大气气溶胶的影响,于2007年春季和秋季对山东半岛南部近海进行气溶胶采集工作.分析结果表明气溶胶水溶性离子中主要无机离子无显著的季节性变化,其中二次离子(nss-SO2-4,NO-3,NH+4)浓度最高,占总测定离子浓度的80%以上.甲磺酸离子浓度春季明显高于秋季,分别为(0.041±0.022)和(0.012±0.003 1)μg·m-3,导致生源硫酸盐对非海盐硫酸盐的贡献率分别为4.5%和1.5%;另一方面海盐源硫酸盐分别占总硫酸盐浓度的3.3%和3.9%,以上结果表明人为输入源占山东近海大气气溶胶中硫酸盐来源的主要部分.春季与秋季气溶胶中nss-SO2-4/NO-3值分别为1.43和1.34,反映出近年来中国大气中SO2/NOx呈现出下降趋势.由此可见,来自陆源的人为活动输送导致山东南部近海大气气溶胶的化学组成呈现出明显的陆源特征.     

青岛胶州湾沿岸城区降水中不同形态汞含量及其沉降量

于2017年10月～2018年9月,在青岛胶州湾沿岸城区连续采集了10个月的降水样品,测定了其不同形态汞的浓度,并计算其湿沉降量。结果表明,降水中总汞(THg)、溶解态总汞(DTHg)、颗粒态总汞(PTHg)、总甲基汞(TMeHg)、溶解态甲基汞(DMeHg)和颗粒态甲基汞(PMeHg)的年体积加权平均浓度(VWM)分别为5.7、3.6、2.1、0.22、0.16和0.06 ng·L~(-1);年沉降量分别为3 145.4、1 975.9、1169.5、118.91、86.63和32.28 ng·m~(-2)。THg浓度与降水量之间呈显著负相关,不同形态汞的湿沉降量与降雨量之间呈显著正相关,说明降水量是影响THg浓度及不同形态汞湿沉降的重要因素。此外,降水中THg浓度还受大气中的PM_(2.5)、PM_(10)、 NO_2浓度和降水pH等反映人为活动的因子的影响,表明人类活动也显著干扰青岛胶州湾沿岸地区降水中汞的浓度。HYSPLIT模型后向轨迹分析结果表明冬季降水中高浓度的汞主要来自于北方和青岛当地的燃煤取暖,而夏季降水中高浓度的甲基汞以及较高的TMeHg/THg比例主要是因为来源于海洋的气团携带了较高浓度的甲基汞,说明海源可能也是青岛胶州湾沿岸城区降水中甲基汞的一个重要来源。     

青岛夏季不同天气下气溶胶中无机氮磷的浓度及沉降研究

本文于2011年8月连续采集了青岛近岸大气气溶胶TSP(总悬浮颗粒物)样品,运用离子色谱法(IC)测定了可溶性无机氮磷组分的浓度,并估算了其干沉降通量,分析了天气过程对无机氮磷浓度的影响,讨论了大气干沉降对黄海初级生产力的影响。结果表明,夏季青岛沿海地区气溶胶颗粒物、NH+4-N、NO-3-N的平均浓度分别为139.96、9.70、3.08μg/m3,NO-2-N和PO3-4浓度很低,分别在0.15和1.00μg/m3以下;NH+4-N含量约为NO-3-N的3倍,二者之和占总无机氮的99%以上。天气过程显著影响颗粒物及无机氮的浓度和组成,雾天时,颗粒物、NH+4-N、NO-3-N的浓度分别升高到晴天时的1.48、1.98和2.21倍,大风天气下分别为晴天时的1.85、2.84和4.50倍;降雨对气溶胶存在明显的清除作用,对颗粒物和无机氮的清除率分别为7.70%~32.97%和54.16%~64.49%。气象要素和气团来源、路径对气溶胶浓度和组成的影响也十分显著。颗粒态无机氮磷的沉降通量分别为0.55和96.14μg/(m2·d),输入黄海后可产生94.51~138.30mg/(m2·month)的新生产力,对总初级生产力的贡献不大,但特殊天气下大气干沉降引起的新生产力可以在短时间内迅速增加。颗粒态无机氮磷的沉降通量之比为13.7,沉降后不会使黄海磷限制的营养盐结构产生明显变化。     

长江口及东海海域大气气溶胶中水溶性离子的分布特征

2006年夏季、冬季和2007年春季、秋季在长江口及东海海域进行了大面积走航采样,通过离子色谱法分析了气溶胶中主要水溶性离子的质量浓度,探讨了其季节变化和海域分布.分析结果表明,K+和Ca2+季节变化显著,海域分布呈现近岸高外海低的趋势,Na+和Mg2+海域分布差异显著;NH4+-N,NO3--N和SO42--S的春、...     

长江口营养盐结构特征及其对浮游植物的限制

根据2013年5月、11月两个航次的调查资料,分析了长江口营养盐浓度及其结构的分布变化,并探讨了营养盐对浮游植物的限制情况。长江口营养盐分布存在季节差异:口门外NO3-N、NO2-N浓度均为春季高秋季低,PO34-P、3SiO2-Si、NH4-N浓度则秋季高春季低,口门内除NO2-N外,NO3-N、PO34-P、SiO23-Si、NH4-N浓度均为秋季高于春季。NO3-N、PO34-P、SiO23-Si浓度从近岸向外海逐渐降低,NO2-N、NH4-N浓度分布规律不明显。NO3-N是DIN的主要存在形态,其占DIN的比例为春季95%、秋季83%。春季、秋季DIN/P均高于16,表现出长江口过量的DIN输入,春季Si/DIN基本小于1,秋季Si/DIN大于1。春季由于硅藻的局部生长使DIN/P异常升高、Si/DIN异常降低,秋季西北部海区受苏北沿岸流影响,呈低DIN/P值和高Si/DIN值分布。受含过量DIN、SiO23-Si的长江冲淡水的影响,春、秋季均表现为PO34-P潜在相对限制。春季由于浮游植物的大量吸收,局部出现PO34-P、SiO23-Si的绝对限制。当同时考虑绝对限制和潜在相对限制时,春季15.38%的站位受PO34-P限制,限制情况较上世纪90年代更为突出。     

春季长江口崇明东滩沉积物-水界面营养盐交换过程研究

2005年3-5月,选取位于长江口崇明东滩的3个典型站点,对沉积物间隙水中营养盐剖面进行了观测;同时,通过模拟现场环境培养的方法测定了营养盐在沉积物-上覆水界面的交换通量.结果表明,间隙水中NH4+和SiO32-浓度比PO43-和NO2-+NO3-一般要高2-3个数量级.沉积物-水界面交换过程在春季表现为对NO3-和SiO32-的吸收,吸收的量在很大程度上取决于上覆水中这两种营养盐的浓度;由上覆水和表层间隙水浓度梯度所决定的分子扩散通量对实际交换通量的控制有限.对NO3-,分子扩散通量占交换通量的比例为到21%;对SiO32-,前者和后者的方向相反;对NH3+,较大的浓度梯度支持显著的释放通量,而在培养过程中并没有发现上覆水中NH4+浓度持续的增长.以上结果都说明其它因素,如浮游植物吸收、颗粒物吸附以及底栖动物扰动在更大程度上决定着崇明东滩沉积物-水界面营养盐的交换过程.     

2016年山东省15个海水增养殖区氮磷分布及其结构特征

氮、磷是海洋生物生长所需要的重要营养元素,其变化对海水增养殖区生态系统结构和功能有着重要影响。文章根据2016年3月、5月、8月及10月的监测资料,分析了山东省15个海水增养殖区氮、磷分布特征,结果表明：DIN浓度范围0.007 30～2.20 mg/L,平均值0.192 mg/L,68.0%的站次浓度介于0.05～0.2 mg/L之间,渤海湾、莱州湾养殖区浓度普遍高于黄海养殖区;PO4-P浓度范围0～0.089 5 mg/L,平均0.005 98 mg/L,81.9%的站次浓度介于0.001～0.015 mg/L之间,约2/3水域为磷限制性贫营养状态。表层、底层海水DIN与PO4-P浓度无明显差异;NO3-N、NO2-N、NH4-N占比分别为68.91%、6.82%、27.27%,NO3-N是DIN的主要存在形式;夏季NH4-N形态比例最高,平均占比36.5%;N/P原子质量比范围1.6～2 532.3,主要范围在10～40,渤海养殖区N/P比明显高于黄海养殖区;DIN分布主要受陆源径流输入影响;PO4-P水平分布无明显规律。     

2002年春、夏季东海赤潮高发区营养盐结构及分布特征的比较

20 0 2年 8月 2 6日— 9月 4日在东海赤潮高发区 ( 2 9°0 0′— 32°0 0′N、1 2 2°0 0′— 1 2 3°30′E)进行了夏季航次的调查 ,利用春、夏季东海赤潮高发区的调查数据 ,系统分析比较了其营养盐结构和分布特征 ,并初步探讨了夏季爆发的中肋骨条藻赤潮与营养盐的关系。与 2 0 0 2年春季相比 ,2 0 0 2年夏季调查海区中SiO3 Si、PO4 P、NH4 N、DON和PN平均浓度比春季有所增加 ,而NO3 N、NO2 N、DOP和PP浓度则有所减小。夏季各种形态磷营养盐主要由PO4 P和PP组成 ,其中PO4 P比春季明显增加 ,PP略有减少 ,DOP显著减少 ;各种氮形态营养盐主要由DIN和DON组成 ,与春季相比DON比例略有增加 ,DIN略有减少。DIN仍以NO3 N为主并有所增加 ,而NH4 N比例基本不变 ,NO2 N有所减少。主要溶解无机态营养盐 ,如SiO3 Si、PO4 P和NO3 N ,以及PP的平面分布整体上呈沿岸海域浓度高、外海浓度低的趋势 ,等值线与海岸线平行的趋势已减弱 ,甚至消失。NO2 N和NH4 N具有明显的水团分布特征 ,与春季有所不同 ;DON和PN与春季具有相同的斑点状分布趋势。另外 ,本航次调查中在 1 1站发现中肋骨条藻赤潮 ,该站表层SiO3 Si浓度较高 ,PO4 P很低 ,其余溶解态氮营养盐及PP与调查海区表层平均浓度接近 ,PN较高。营养盐结构中 1 1站表层     

夏季长江口无机氮的加入与转移 偏移理论稀释曲线的解释

利用2006年夏季长江口调查数据分析了长江口海域硝酸盐(NO3-)、亚硝酸盐(NO2-)、铵盐(NH4+)大面分布,NO3-浓度呈近岸高、外海低的特征,NO2-和NH4+浓度在上海市排污口位置有高值区并向外扩散。NO3-,NH4+浓度总体上符合咸淡水混合之稀释效应,与盐度的相关系数(r2)分别为0.815,0.255,呈保守行为,而NO2-浓度与盐度的相关性系数为0.074,呈非保守行为。在确定了淡水端元和咸水端元的基础上,做出理论稀释曲线TDL(theoretical dilution line),由于上海市污染物的输入,淡水端元NO3-,NO2-,NH4+浓度不同程度地正偏于TDL,在外海深层水范围内有机颗粒矿化再生亦呈加入态势。对应高溶解氧的盐度羽状峰处,由于真光层初级生产较强,表层NO3-浓度负偏于TDL约1~19μmol/dm3,NO2-,NH4+浓度也存在不同程度的减小。在长江口最大浑浊带附近,由于高浓度悬浮物吸附NH4+而呈现明显的迁出机制。外海表层海水三氮营养盐浓度数据点偏离TDL程度较小,但在底层由于来自上层的有机颗粒耗氧分解而再生出营养盐,使NO3-,NO2-,NH4+浓度数据一般在TDL之上。     

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,