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1.
《海洋湖沼通报》2016,(6)
通过调查环渤海湾多个海域表层海水、沉积物及海洋生物体中石油烃总量及苯并(a)芘的含量,研究了石油污染对海区环境和生物的影响。并通过分子荧光法和液相色谱法分别研究不同海洋环境中、同一海区不同生物品种中、不同海区相同生物品种中以及同一海区的环境和生物体中石油烃及苯并(a)芘含量的关系,分析不同海区石油烃污染状况,对比不同生物品种对石油烃的富集能力。结果表明,所监测海域生物体中石油烃和苯并(a)芘含量趋势均为:棘皮类贝类甲壳类鱼类;调查海域海水中石油烃含量范围为(0.013~0.285mg/L),属轻度石油烃污染,;海洋生物中石油烃和苯并(a)芘含量范围分别为(0~57.2mg/kg)和(0~2.29μg/kg),样品中苯并(a)芘含量均低于限量值,石油烃超标率为6.7%,基本达到水产品食用安全标准。 相似文献
2.
文蛤(Meretrix meretrix)体内氨基脲含量与环境相关性研究 总被引：2，自引：0，他引：2
采用超高效液相色谱-串联质谱法进行了文蛤体内氨基脲含量与环境相关性研究。在(13±1)℃的水温条件下,将文蛤分别浸浴于氨基脲浓度1.0μg/L、5.0μg/L的海水中6天进行吸收试验,第7天起隔天换水进行消除试验,结果表明:文蛤对水体中氨基脲的富集能力较低,蓄积量随时间的延长和给药浓度的增加而增加。氨基脲在不同浓度中具有相似的消除规律:初始阶段均具有较高的消除速率,随后消除趋势趋于平缓,并在一段时间内维持一定质量分数;至试验结束时,低浓度组和高浓度组文蛤体内氨基脲最终降低至低于检出限(0.5μg/kg);本研究所得的药时曲线对贝类氨基脲污染的净化提供了数据支持。 相似文献
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利用电感耦合等离子体质谱仪(ICP-MS)对渤海湾天津海域人工鱼礁区多相介质(海水、沉积物和大型底栖生物体)中重金属Pb含量进行了测定,运用不同评价方法分析了其空间分布特征及其潜在生态风险。结果表明:礁区海水Pb含量的变化范围为0.003-0.024μg/L,平均值0.008±0.007μg/L,最高值出现在9号站位;最低值是5号站位。沉积物中Pb含量的变化范围为0.138-0.470 mg/kg,平均值0.273±0.106 mg/kg,各站位沉积物Pb垂直分布特征为下层中层上层。风险评价结果表明,礁区沉积物Pb潜在生态危害指数属于低生态风险;地累积指数属于偏中度污染程度;富集系数属于无～轻的污染程度。礁区内生物体Pb含量的变化范围为0.004～0.519 mg/kg,平均值0.185±0.170 mg/kg;礁区生物体Pb的BCF普遍高于BAF值;其健康风险系数远小于1,这表明Pb对暴露人群无明显健康风险。 相似文献
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采用共沉淀法分析测定了阳江核电站邻近海域2012—2013年海水样品总α、总β的放射性比活度、表层沉积物样品中总β的放射性比活度以及2013年生物样品中总β的放射性比活度。结果表明:2012—2013年两年间阳江核电站邻近海域海水中总α的放射性比活度范围为:0. 083～0. 205 Bq/L,平均值为0. 134 Bq/L;总β的放射性比活度范围为:0. 029～0. 059 Bq/L,平均值为0. 043 Bq/L。与渤海、黄海、东海、珠江口等其他海域相比,阳江核电邻近海域总α、总β放射性比活度水平相对较低。2012—2013年阳江核电站邻近海域表层沉积物中总β的放射性比活度范围为:620～1 125 Bq/kg (干重),平均值为814 Bq/kg (干重)。与渤海、黄海、东海、珠江口等各海域沉积物相比,研究海域沉积物中总β的放射性比活度位于中等水平。2013年阳江核电站邻近海域生物样品总β的放射性比活度范围为:16. 1～74. 7 Bq/kg,平均值为39. 4 Bq/kg,其中鱼类的总β平均值为64. 6 Bq/kg,虾类的总β平均值为36. 8 Bq/kg,贝类的总β平均值为16. 7 Bq/kg,呈现鱼类虾类贝类的分布趋势。 相似文献
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《应用海洋学学报》2015,(1)
通过2013年8月对福建沙埕港海域海水、沉积物及贝类体内重金属进行的调查,结合历史资料对重金属的含量分布及来源进行了讨论和分析.结果表明:沙埕港表层海水中Cu、Cd、Hg和As等溶解态重金属含量整体处于较低水平,但Pb含量在大部分海域略超海水水质一类标准.沉积物中Pb、Cd、Hg和As含量均低于海洋沉积物一类标准,而Cu在上段八尺门海域及中段罗唇溪入海口附近存在超标现象.地积累指数评价表明Pb和Cd处于无污染状态,而Cu、Hg和As 3种重金属在不同区域存在轻微污染.港内八尺门点头镇附近海域采集的2种贝类均存在不同程度的重金属污染.其中缢蛏(Sinonovacula constrzcta)体内重金属污染较轻,而褶牡蛎(Ostrea plicatula)体内重金属污染较重,Cu和Cd污染指数均在10以上.浙闽沿岸流是沙埕港Pb、Cd、Hg和As等重金属的主要来源,而白琳石材加工排放的污水是造成沙埕港上段八尺门浅滩区重金属Cu污染的主要原因.此外,中段罗唇溪入海口附近海域Cu、Pb和Cd含量较高,可能同罗唇港修造船厂的污染排放有关. 相似文献
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海口市龙昆沟入海排污口邻近海域水质状况与评价 总被引：1，自引：0，他引：1
根据2007-2009年海口市龙昆沟入海口邻近海域的水质监测结果,采用水质单因子污染指数评价法对该海域的水质状况进行分析和评价。结果表明:海口市龙昆沟入海口邻近海域受到无机氮、活性磷酸盐和石油类污染较为严重,化学耗氧量及生化耗氧量也出现轻度污染,排污口邻近海域海水水质环境有恶化的趋势。并且依据分析结果,提出了相应的防治对策。 相似文献
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《中国海洋大学学报(自然科学版)》2015,(12)
对长江口及邻近海域表层沉积物中的生物硅进行了测定,分析了生物硅的分布特征及影响生物硅保存与分布的因素。结果表明:在整个海域调查范围内,表层沉积物中BSi含量范围为0.14%~0.70%,平均值为0.41%,与世界其他近海沉积物中BSi含量相比,处于中等偏下水平。黏土矿物和粉砂较多的沉积物中富集着更多的BSi,而砂含量较高的沉积物中BSi的含量较低。表层沉积物颗粒比表面积越大,越有利于BSi的赋存和累积。BSi的分布特征和TOC、TN分布存在一定的关联,说明2011年8月长江口及邻近海域表层沉积物中有机物的来源之一可能为硅藻;相对于TOC,BSi有更高保存率。表层沉积物表面富集着丰富的底栖硅藻,这是表层沉积物中BSi比同时期悬浮颗粒物中BSi的平均百分含量高一个数量级的重要原因。调查区域内BSi的沉积通量显著高于沉积物-海水界面SiO2-3-Si的释放通量,说明沉积物-海水界面以BSi的沉积为主,长江口及邻近海域是BSi的汇。 相似文献
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2011年5月采集莱州湾及东营近岸海域鱼、贝、甲壳(蟹、虾)、头足四类235个生物体样品, 用气相色谱法测定其中六六六(HCHs)、滴滴涕(DDTs)及多氯联苯(PCBs)含量, 对其残留水平、分布、组成特征及污染源进行分析, 对污染现状及人体健康风险进行了评价。结果表明, 研究海域生物体中HCHs含量(湿重) N.D.—5.73?g/kg; DDTs含量(湿重) 0.122—304?g/kg; PCBs含量(湿重) N.D.—6.51?g/kg。根据各同分异构体百分比组成分析, 莱州湾及东营近岸海域近期无新的大面积HCHs、DDTs污染输入。与同类研究相比, 莱州湾及东营近岸海域生物体PCBs含量处于较低水平, 而HCHs和DDTs含量处于中间水平。通过污染指数分析得出: 所有生物体HCHs、PCBs均未受到污染; 55%生物体DDTs受到不同程度污染。研究海域生物体HCHs、DDTs、PCBs含量低于各国食品安全限量; 以美国环保局推荐方法评价本海域生物体HCHs、PCBs食用致癌风险为可接受风险, 但是DDTs含量存在一定的致癌风险。 相似文献
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文章根据2011—2015年北部湾广西近岸海域海水、沉积物、海洋生态以及生物体质量监测与调查结果,采用单因子污染指数评价法、综合污染指数法、生物多样性指数法、质量分级评价法等对该海域环境质量状况进行评价,采用spearman秩相关系数法对该海域水质和沉积物质量变化趋势进行分析,结合广西海洋生态状况剖析海洋环境问题。结果表明:北部湾广西近岸海域海水质量良好,表层沉积物质量优良;但生物多样性指数偏低,水质异常和藻类异增殖现象增多,重要生物生境受侵扰严重,局部海域污染现象持续存在,入海河流未完全消除劣五类水体,环境隐患不可忽视。建议地方政府及相关部门围绕新《中华人民共和国海洋环境保护法》和水污染防治行动计划等要求,采取有效措施,全力保障广西海洋生态环境安全。 相似文献
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Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
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. 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
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. 相似文献
13.
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。 相似文献
14.
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. 相似文献
15.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
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. 相似文献
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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. 相似文献
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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. 相似文献
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Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans 总被引：1，自引：0，他引：1
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. 相似文献