共查询到20条相似文献，搜索用时 62 毫秒
1.
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。 相似文献
2.
基于2011年秋季钦州湾东部近岸海域的水质调查数据,利用单因子标准指数法及模糊综合评价模式对钦州湾东部近岸海域海水水质现状进行综合评价。结果表明:钦州湾东部近岸海域秋季海水中DO,COD,BOD5,PO4-P,DIN,石油类,Cu,Pb,Zn,Cd,Cr,As,Hg的平均浓度分别为:6.34 mg/L,1.10 mg/L,0.74 mg/L,0.02 mg/L,0.26 mg/L,0.023 mg/L,2.2μg/L,1.1μg/L,4μg/L,0.14μg/L,0.2μg/L,0.68μg/L,0.036μg/L。该海域海水中DO,COD,BOD5,石油类,Cu,Pb,Zn,Cd,Cr,As,Hg的平均浓度均符合国家一类海水水质标准,PO4-P和DIN的平均浓度超出了一类海水水质标准。以单因子标准指数法进行评价,钦州湾东部近岸海域水质级别为II级。以模糊综合评价模式进行评价,钦州湾东部近岸海域水质级别为I级。PO4-P和DIN是钦州湾东部近岸海域秋季海水中的主要污染物。 相似文献
3.
东海沿岸不同区域贝类体内石油烃含量的分布特征及其评价 总被引：4，自引：0，他引：4
根据 2006 年 5 月对东海沿岸 9 个区域贝类的监测结果,探讨分析了调查海域的6种贝类体内石油烃含量的分布特征,采用单因子污染指数法按照海洋生物质量 ( GB 18421 - 2001 ) 评价标准评价了监测海域贝类的石油烃污染状况.结果表明,东海沿岸的9 个海域的 6 种受测贝类体内石油烃含量分布范围1.28 ～ 37.6 mg / kg ( 湿重 ),平均含量10.78 mg / kg,总体上符合<海洋生物质量>一类标准 ( 15.0 mg / kg );6 种贝类体内种间石油烃平均含量分布从大到小依次是:牡蛎＞毛蚶＞四角蛤蜊＞文蛤＞贻贝＞泥蚶,其中牡蛎平均含量达到 15.62 mg / kg,超出海洋生物质量一类标准.从区域分布看,长江口和江苏如东沿岸海域的牡蛎石油烃的平均污染指数较高,分别为 1.91 和 1.19,受到重度污染. 相似文献
4.
象山港海域中石油烃含量分布特征及其评价 总被引：3，自引：0，他引：3
本文分析了象山港海域石油烃含量的分布规律,并对海域遭受污染程度进行了评价,该海域的石油含量在0.01～0.45mg/dm~3之间,平均值为0.072mg/dm~3,比一类海水标准浓度值高0.44倍,油污染平均指数Ai值为1.5,表明该海域已有相当程度的油沾污。 相似文献
5.
《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
6.
为了解大连新港7.16溢油事故发生后5年间大连湾受污染海区生态恢复程度,同时探究大连湾表层海水和沉积物中微生物对石油污染的长期响应策略,对大连湾表层海水和沉积物中石油烃含量的分布、异养细菌和石油烃降解菌丰度的年度变化特征,以及细菌丰度与环境因子间相关性进行了研究。结果表明,溢油事故发生后2年间,大连湾表层海水中石油烃含量由溢油初期2010年9月的0.22~0.67 mg/L降到0.0025~0.05 mg/L(2012年5月),海水质量也由三类海水转变为一类海水;沿岸站位BQ012表层沉积物中石油烃含量也由2011年12月的7 133μg/g降低到2014年的926μg/g,其表层沉积物质量也由三类转变为一类沉积物质量标准。溢油后2个月内表层海水中异养细菌及石油烃降解菌丰度升高至105CFU/m L和104CFU/m L,随着时间推移各站位细菌丰度基本呈下降趋势,5年后细菌丰度回落了1~2个数量级并恢复到溢油前的历史水平。表层沉积物中石油烃降解菌丰度由溢油后2个月的105CFU/g降低到2013年的102CFU/g。石油烃降解菌与异养细菌的比值(HDB/HB)与石油烃含量呈极显著的正相关(P0.01),而与营养盐和溶解氧等主要环境因子相关性不大,因此认为其可作为海水中石油烃类污染评价的指标。 相似文献
7.
于2011年10月对大亚湾坝光海域表层海水和沉积物的酸可挥发性硫化物(AVS)及相关环境因子进行了调查研究.结果显示,20个测站表层海水的AVS含量在0.039 ～0.129 mg/dm3之间,平均0.070 mg/dm3,区域分布规律不显著;12个测站的表层沉积物中均检测出AVS,其含量(干重)范围是12.8 ～ 867.7 mg/kg,平均为272.4 mg/kg,整体呈近岸较高、离岸较低的分布规律.相关性分析显示,表层水体pH值、CCOD和CDo等环境因子与CAVS相关系数的绝对值均较小,相关性特征不明显;表层沉积物中的CAVS与Eh之间的相关系数为-0.957,呈高度相关性,符合挥发性硫化物含量较高的沉积物处于较强还原状态的普遍规律;大亚湾表层沉积物中的CAVS与pH值、CTOC的相关系数分别为-0.065和0.219,相关性不显著.单因子污染指数评价结果表明,大亚湾坝光海域表层海水硫化物含量已超过所在自然保护区(一类标准)和养殖区(二类标准)所要求的水质标准,局部水体已受到污染;表层沉积物中硫化物含量符合国家一类标准,环境质量良好. 相似文献
8.
北部湾东部沉积物中石油烃分布与累积 总被引：1，自引：0，他引：1
为揭示北部湾东部沉积物中石油烃的污染现状,分析了24个表层样和1只柱状样的石油烃含量,并运用210Pb法对柱状样进行了定年。结果表明2007年北部湾东部表层沉积物中石油烃含量范围为62.94~107.80μg/g,平均为83.03μg/g,总体污染较轻。石油烃含量的低值主要出现在海南岛西侧海域,而高值主要分布在海南岛西北泥质沉积区和湾北近岸海域,油气平台附近的石油烃也略微富集,距源区距离是决定沉积物中石油烃含量的重要因素。柱状样B349基于210Pb法获得的平均沉积速率为0.53 cm/a,其中石油烃含量范围为68.31~94.77μg/g,石油烃含量的2次重要变化可能分别与20世纪80年代涠洲海域石油开发初期的溢油和20世纪90年代以来经济增长所伴随的排污增加相对应。 相似文献
9.
钦州湾海水中石油烃时空变化特征及其影响因素 总被引：3，自引：0，他引：3
2009年1月至11月对广西钦州典型养殖海湾-钦州湾海域表层海水石油烃进行了4次采样调查,分析该海域石油烃污染状况,探讨石油烃的时空分布特征及其影响因素。结果表明,钦州湾表层海水石油烃的质量浓度在0.001~0.095 mg/L之间,平均值为0.022 mg/L;季节变化呈现夏季最高,秋、冬季次之,春季最低的特点,夏、冬季海水受到不同程度石油污染,春、秋季均达到国家《海水水质标准》二类标准。水平分布上总体呈现春、秋季节外湾大于内湾,夏、冬季节内湾大于外湾的特征。钦州湾水产养殖活动及陆地径流输入是影响石油烃时空变化的主要因素。春季石油烃的质量浓度与温度和溶解氧等环境因子有着较好的相关性,夏季石油烃和溶解无机磷存在显著正相关。总体上钦州湾海域目前受石油烃污染程度较轻,仍有一定接纳自净能力。 相似文献
10.
湛江港海域海水和表层沉积物重金属分布特征及其污染评价 总被引：2，自引：0，他引：2
根据2013年01月(冬季)和2013年06月(夏季)的调查数据对湛江港海域海水和表层沉积物中的重金属(铜、锌、铅、镉、砷和汞)进行了研究,调查结果显示调查海域海水和表层沉积物中重金属含量呈现岸边海域高于深海海域,东海岛北面海域高于东面海域;对比冬季和夏季的调查结果,调查海域海水中重金属平均含量夏季高于冬季。用单项污染指数对海水中的重金属进行了评价,结果表明,冬、夏两季海水中的Pb污染较明显,Cu和Zn轻度污染,其余元素(Cd,As和Hg)均未超过相应的国家海水水质标准限值,夏季重金属污染指数高于冬季,可能与陆源重金属污染物入海的影响有关;表层沉积物中重金属均低于相应的标准限值,沉积物环境质量状况良好。采用瑞典科学家H覿kanson的潜在生态危害指数法进行评价,沉积物中重金属的潜在生态危害较轻,生态危害程度HgAsCdPbCuZn。 相似文献
11.
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
12.
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
13.
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
14.
Derek V. Ellis 《Marine Georesources & Geotechnology》2001,19(1):51-63
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. 相似文献
15.
G. Parthiban 《Marine Georesources & Geotechnology》2000,18(3):223-235
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. 相似文献
16.
17.
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. 相似文献
18.
19.
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
20.
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