大亚湾内、外海域重金属分布对比及其潜在生态风险评价

为促进大亚湾区的海洋生态环境保护和可持续发展,文章以铜等9种重金属为指标,根据相关规范和标准,分别调查大亚湾内、外海域的海水、表层沉积物和生物质量,并采用单因子污染指数和内梅罗综合污染指数,对比重金属的污染程度,具有创新性;同时,以表层沉积物为代表,采用潜在生态风险指数,评价大亚湾海域的潜在生态风险。研究结果表明:大亚湾海域海水、表层沉积物和生物中的重金属含量大部分符合相关一类或推荐的标准;海水中的主要重金属为铅,综合污染指数湾外低于湾内,可能与人类活动和海水交换有关;表层沉积物中的主要重金属为钒,综合污染指数湾内低于湾外,可能与钒的最大值超标有关;生物体内重金属的综合污染指数,甲壳类和头足类湾外低于湾内,而鱼类和贝类湾内低于湾外,但差距均不明显;大亚湾海域多种重金属的潜在生态风险等级为很高,其中汞为首要潜在生态风险因子,须引起高度关注。     

七连屿海域表层海水及沉积物重金属环境质量评估

为研究七连屿海洋环境质量状况,于2017年8月在七连屿海域布设20个采样站位,共采集到22个表层海水样品及6个表层沉积物样品,通过原子吸收分光光度计及原子荧光分光光度计测定海水及沉积物中重金属(Cu、Pb、Zn、Cd、Cr、As、Hg)的含量,采用单因子评价法、综合污染指数法及相关性分析对水质重金属污染程度进行研究,并采用单因子评价法及Hankanson潜在生态风险指数法分别对沉积物质量及沉积物中重金属潜在生态风险进行评价。结果表明,2017年七连屿海域表层海水重金属含量CZn>CPb>CAs>CCr>CCu>CCd>CHg,部分站位海水铅含量超一类海水水质标准,但是综合污染指数小于1,该调查海域表层海水属于清洁型;海水中Zn-As、Cr-Cd含量之间存在显著负相关关系,此两组元素存在明显异源性;该调查海域表层沉积物重金属含量均符合第一类海洋沉积物质量标准,沉积物重金属对海洋生态系统仅存在轻微生态风险。     

厦门典型养殖海域沉积物中重金属及其环境质量评价

根据2005年8月对厦门典型养殖海域——同安湾及大嶝海域表层沉积物的调查资料,分析了表层沉积物中重金属的质量分数,研究了表层沉积物中有机质以及与重金属的相关性,并运用单因子评价法评估了沉积环境质量。结果表明:同安湾和大嶝海域表层沉积物中Hg,Cd,Pb,Cu,As的平均质量比分别为0.060,0.057,31.8,20.4,7.27mg/kg和0.047,0.096,26.6,25.2,6.65mg/kg;各重金属元素之间(除Cd外)呈显著的正相关,与有机质也呈很好的正相关关系;各要素均未对研究海域表层沉积物构成污染,表层沉积物质量符合国家一类沉积物标准。     

獐子岛贝类养殖区表层沉积物重金属分布特征及潜在生态危害评价

研究了獐子岛虾夷扇贝养殖区表层沉积物中Pb、Cd、Cu、Zn等有害重金属的含量及时空分布,并采用瑞典学者Hakanson的潜在生态危害指数法对该区域重金属的分布特征和生态风险进行了分析。结果表明,獐子岛海域表层沉积物Pb、Cd、Cu、Zn含量均是在夏季较低、冬季较高,最高含量分别为9.17±2.05、0.06±0.014、6.71±2.01、24.94 mg/kg±5.21 mg/kg,远低于国家一类海域标准及Hakanson提出的全球工业化前沉积物中相应污染物的背景值。综合评价,该海域表层沉积物中重金属的污染程度不具有生态风险性,整个养殖区养殖环境良好,为优良的贝类增养殖海域。     

温州近岸海域石油烃分布特征

根据2006—2009年温州近岸海域石油烃的调查结果,分析海域石油烃污染的分布特征,并采用单因子指数法对石油烃污染程度进行了评价。结果表明,调查海域海水中石油烃含量范围为ND~0.085 mg/L,平均含量为0.018 mg/L。除2008年和2009年各有1个测点超出一类海水标准限值(≤0.05 mg/L)外,其余测点石油烃含量均未超出一类标准限值。2009年沉积物石油烃平均含量为20.7×10-6,各测点均低于一类沉积物标准值,表明温州近岸海域还未明显受到石油烃污染。     

大亚湾表层沉积物中污染物质的地球化学行为研究

大亚湾表层沉积物以粉砂质粘土、粘土质粉砂及粉砂为主组成。表层沉积物的污染表现以硫化物及铅、锌、汞、砷为主,其中硫化物、铅、锌的污染现象在本海区普遍出现。污染物质从海水向沉积物转移是多因素综合作用的结果,悬浮物、生物及沉积物的吸附等多种转移方式都可能存在。沉积物中某些元素之间存在一定的相关性,但沉积物与其粒度组成的粘土含量及海水理化要素之间无明显相关性。     

兴化湾表层海水和沉积物中重金属含量的时空变化特征

根据福建兴化湾2006年12月（冬季）和2007年4月（春季）表层海水以及2007年3月表层沉积物的监测资料,分析了该海域表层海水和沉积物中重金属Cu、Pb、zn、Cd、Hg和As含量的时空变化特征,评价了该海域重金属的污染程度．结果表明：冬季,调查海域表层海水中cu、Pb、zn、cd、Hg、As的含量范围分别为〈0．20～2．42、〈0．03～1．08、〈3．1～16．5、〈0．010—0．043、〈0．007～0．170、0．82～4．00肌g／dm’;春季其含量范围分别为0．91～3．80、0．18～3．40、8．7～36．0、〈0．Ol～0．22、〈0．007～0．063、0．63～1．58~g／dm’．这两季表层海水重金属的测值均低于《海水水质标准（GB3097—1997）》第二类标准值,其中春季cu、Pb、zn、cd含量的均值高于冬季,可能与陆源重金属污染物入海的影响有关．兴化湾表层沉积物中cu、Ph、zn、Cd、Hg和As的含量范围分别为7．60～22．oo、22．4～39．1、54．2～114．0、0．045～0．082、0．020～0．066、5．00～10．20mg／kg,均低于《海洋沉积物质量（GB18668_2002）》的第一类标准值．该湾表层海水和沉积物中重金属含量的平面分布特征呈近岸海域较高．此外,对其历年来监测结果的比较表明,兴化湾表层海水和沉积物中cu和Ph含量的多次监测值较接近,但重金属zn含量的监测值存在着波动现象．     

福建兴化湾中部表层海水及沉积物中重金属含量特征与生态风险评价

分析研究了兴化湾中部表层海水Cu、Pb、Zn、Cd、Cr、Hg、As的含量发现,表层海水中Cu、Pb、Zn、Cd、Cr、Hg、As含量均符合海水水质一类标准,对表层沉积物中Cu、Pb、Hg、Cr、Cd、As等6种重金属含量分析表明,6种重金属含量均符合海洋沉积物质量一类标准.表层海水中重金属与环境因子相关性分析表明,6种重金属与环境的相关性在不同季节中存在差异;而表层沉积物中重金属与环境因子的分析表明,重金属具有相近的来源,有机质对沉积物中重金属的含量分布具有重要影响.主成分分析结果表明,兴化湾中部表层沉积物7种重金属主要来源为有机质的降解、沉积环境本身及工业排污的影响,其贡献率分别为59.48%、15.30%、10.98%,3个主成分的贡献率合计达到85.76%.潜在生态危害指数法评价结果表明,Cu、Pb、Zn、Cd、Cr、Hg、As均属轻微生态危害.     

胶州湾的重金属污染研究

根据胶州湾海水和表层沉积物样品中重金属含量的分析，探讨了胶州湾的污染现状和发展趋势。将海水和表层沉积物中的重金属含量与该区周边岩石的重金属含量及国家环境标准对比研究表明，胶州湾海水中Cu和Cd含量符合国家一类海水标准，Pb的污染最为严重。胶州湾东部表层沉积物中的Cd、Hg、Pb的含量均超过一类沉积物的国家标准。其主要污染区位于大港至李村河口一带，污染源主要来自陆源污染物，并由河流排出入海所致。胶州湾中部的重金属含量低于国家标准，说明环境状况良好。     

广东雷州珍稀海洋生物国家级自然保护区水体和沉积物中石油类含量与分布特征

为了探讨广东雷州珍稀海洋生物国家级自然保护区海域水体和沉积物中石油类的含量及其分布特征,文章于2017年和2018年分别对保护区海域的石油类进行了调查。结果表明,保护区表层水体石油类含量为0.003~0.066mg/L,平均含量为0.015mg/L,平均污染指数为0.30,保护区水体中的石油类基本符合一类海水水质标准。保护区表层沉积物中石油类含量为3.0~54.8mg/kg,平均值为11.109mg/kg,符合海洋沉积物第一类质量标准。保护区水体和沉积物中石油类含量的变化规律基本相似,但是沉积物中石油类含量的变化更大。根据调查数据分析,保护区水体中石油类的主要来源是保护区社区小型渔船航行排放的石油类,以及保护区周边渔船在航行过程排放的石油类扩散到保护区海域。     

连续台风对海表温度和海表高度的影响

利用多卫星观测资料,分析了2008年9月3个连续台风前后的海表温度(SST)和海表高度距平(SSHA)的时空变化特征,并探讨了影响其变化的主要因子。结果表明:(1)3个台风引起了强烈的上升流(1×10-5~150×10-5 m/s),海表显著降温(1~6 ℃),海表高度也有不同程度降低(10~50 cm);(2)台风引起的SST最大降温中心与SSHA负值或中尺度冷涡的区域中心十分吻合,同时台风使得先前存在的海洋中尺度冷涡得到加强;(3)同一区域台风对SST影响程度大小受台风的强度、移动速度以及台风对海面强迫时间等因素控制;(4)在原先SSHA为正值的海域,3个台风连续强迫下使得局地洋面形成一个SSHA为负值的中尺度涡,这与单一"打转"台风强迫海洋生成中尺度涡的现象不同。因此,对于西北太平洋海域而言,频发的台风在中尺度涡生消演变过程中的影响应不容忽视。     

海表温度与海表气温位相关系

采用1982-2012年NOAA最优插值海表温度(第二版)数据资料和NCEP/NCAR再分析海表气温数据资料,利用均方差分析法,分析海表温度和海表气温的年际变化特征。将31年数据按照El Nin軌o/La Nin軌a事件分为a,b,c 3组,利用超前/滞后相关性分析法,将中低纬度海域海表温度异常(SSTA)与海表气温异常(SATA)做超前/滞后相关分析,得到每个格点SSTA与SATA之间相关性最显著的时间,从而确定SSTA与SATA之间的超前/滞后相关关系。研究结果表明:中纬度海域以SATA超前SSTA为主,SATA滞后SSTA主要分布在20°S-20°N的热带海域。SATA与SSTA超前/滞后天数统计结果均呈现双峰型分布,SATA超前峰值出现在10 d左右,SATA滞后峰值出现-7 d左右。El Nin軌o/La Nin軌a事件的出现,对海气超前/滞后相关关系具有一定影响。     

Distribution and cycling of dimethylsulfide in surface microlayer and subsurface seawater

Laboratory experiments, along with in situ investigation in Funka Bay, Japan, were conducted to determine the enrichment factor (EF) of dimethylsulfide (DMS) in the sea surface microlayer, as well as its the production and consumption rates. The EF of DMS in the microlayer was largely affected by various factors including sampling methods, sampling thickness, temperature, salinity, and DMS concentration in bulk water. In all cases but the sealed system, a part of DMS in the microlayer was always unavoidably lost during sampling. High temperature, great wind speed, and slow sampling would increase the extent of loss of DMS due to volatilization. In the field, the screen-collected samples usually exhibited greater microlayer enrichment for DMS than the plate-collected samples, showing that the screen sampler might be more effective for collecting the in situ microlayer DMS. The production and consumption rates of DMS in the surface microlayer were higher than those in the bulk water and these two rates were significantly correlated with the microlayer DMS concentrations. Moreover, the EF of DMS appeared to be related to the microlayer production rate of DMS, providing evidence supporting the observed DMS enrichment in the microlayer. The DMS production and consumption rates were not directly related to its concentrations in the bulk water, suggesting that the processes of production and consumption of DMS were very complex. In the surface microlayer, the biological turnover time of DMS varied from 0.4 to 1.9 days, with an average of 0.9 days, which was about 540-fold greater than the mean DMS sea–air turnover time (2.4 min). Thus, the biological process occurring within the microlayer can be neglected when we consider the sea–air exchange of DMS. Considering the microlayer production rate of DMS (an average of 9.7 nM day⁻¹) to be too small to counteract the sea-to-air removal of DMS, the main source of DMS in the microlayer appears to be through vertical transport by turbulent diffusion from the underlying water.     

Fatty-acid composition of dissolved and particulate matter in surface films

Lipids containing fatty acids, together with other surface-active substances, can form continuous films on the sea surface. Owing to the complex structures of fatty acids, they are suitable for use as tracers in investigations of the origin and fate of surface films.Surface films were sampled west of the island of Sylt from the 20th to 22nd of August, 1974. After filtration, the fatty-acid composition of the chloroform-soluble part was analyzed in the particulate and dissolved fractions, respectively. Thereby different types of surface films could be characterized, which varied in total quantity, as well as in the relative amounts of fatty acids in the filtrate and particulate matter.It is plausible that such fatty acids will accumulate at surfaces which are chemically stable, as e.g. the saturated fatty acids, which are more resistant to photolytic and chemical degradation than their unsaturated counterparts.The fatty-acid patterns changed as soon as the film contained a large amount of particulate lipids, which shows correlations to the dissolved surface-active substances. Thus, correlations between the fatty-acid pattern in the surface film and that of Prorocentrum micans could be determined.     

The behaviour of iodine and bromine in estuarine surface sediments

The distribution of iodine and bromine was examined in sediments which receive inputs of marine and terrigenous organic matter. The I and Br concentrations are directly related to the content of ‘marine’ organic matter defined using carbon/nitrogen ratios. In the Etive sediments both Br and I may be used as an indicator of ‘marine’ organic matter; Br is of general application as the $\text{Br}\text{C}{}_{\mathrm{mar}}$ ratio (180 × 10^?4) is similar to ratios in other sedimentary environments but the use of I is restricted as the $\text{I}\text{C}{}_{\mathrm{mar}}$ ratio is unlike those in other sediments. Experimental study of iodine sorption clearly shows the importance of decaying marine organic matter and oxygenated conditions in the incorporation of iodine by sediments. This suggests that the mechanism of incorporation of iodine by seston previously proposed is probably an important pathway to sediments. The similarity of Br association with marine organic matter suggests that Br sorption as opposed to residual enrichment may be important for sediment Br accumulation.     

台湾海峡1989年初冬海面温度场和流系的卫星遥感初析

应用NOAA卫星AVHRR热红外遥感数据,通过计算机运算处理获得的海面温度专题图象,对台湾海峡及其邻近海域1989年初冬海面温度场及流系(黑潮、台湾暖流、浙闽沿岸流、南海暖流及台湾浅滩上升流)进行初步分析,利用卫星遥感手段佐证了过去用传统海面船测方法得出的一些结论,并获得了一些与过去有异的结果,得出1989年初冬浙闽沿岸流可达福建泉州湾和厦门港附近等结论,同时发现了该海域流系边界形成的几处波长在30～100km不等的切变波.     

Characterization and seasonal variations of surface active substances in the natural sea surface micro-layers of the coastal Middle Adriatic stations

Surface micro-layer (ML) samples were collected in different seasons over a long time period in the coastal area of the Middle Adriatic Sea including the seawater Rogoznica lake location and the semi-enclosed estuarine Martinska station. Natural surface micro-layers were studied as original samples and as ex-situ reconstructed films after previous extraction by organic solvents of different polarities (n-hexane and dichloromethane). Using alternating current (AC) voltammetry (out-of-phase mode) the concentration of surface active substances (SAS) in original ML of both locations was determined, and the enrichment factor (EF) in the ML was related to the underlayer water (ULW) samples collected at 0.5 m depth. Seasonal variability of SAS concentrations of the ML was observed at both locations. The ex-situ films were studied using a modified AC voltammetry method (out-of-phase mode) transferring an organic extract of natural micro-layers spread onto electrolyte from the air-water interface to the mercury electrode surface. The comparison of adsorption characteristics for model lipids of different polarities and those of transferred ex-situ reconstructed films has revealed that different types of lipid material were present in each ex-situ film of the same micro-layer. Additional characterization of the surface active material of natural MLs was carried out by AC voltammetry (in-phase mode) using cathodic reduction of cadmium ions as an indicator of permeability of different films adsorbed at the mercury electrode. The SAS of ML of both investigated locations induced an inhibition effect to the reduction of cadmium ions. Seasonal variations of inhibition have also been noticed. The electrochemical study contributed to the physicochemical characterization of the surface active matter of the surface micro-layer with the emphasis to the role of lipids which, although they represent a minor fraction of the total micro-layer organic material, contribute considerably to the micro-layer formation and stabilization at the air–water interface.