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1.
根据2009年8月至2010年7月的水质调查数据,运用水质质量单项标准指数法、综合指数WQI法、有机污染指数法和富营养化评价法等方法,对特呈岛红树林自然保护区的水环境质量进行评价。结果表明,特呈岛红树林自然保护区海水主要污染物为DIN、DO、石油类和PO43-P,其年平均浓度分别为0.54、4.83、0.061和0.033mg/L,单项平均污染指数分别为1.81、1.30、1.22和1.10,其中DIN的污染情况最严重,所有监测站位DIN含量均远未达到二类海水水质标准。特呈岛红树林自然保护区水质综合污染指数的平均值为1.42,说明该区水环境质量总体上属于轻度污染水平;有机污染指数的平均值为2.44,有机污染程度属于4级,表明该区水域受到轻度有机污染;富营养化指数的平均值为5.96,处于高富营养化状态。由于湛江港的影响,特呈岛红树林自然保护区水质受到较严重的影响。 相似文献
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文章利用2017—2019年杭州湾海域12个航次的水质监测资料，分析水质调查项目中石油类的分布特征。研究结果表明：2017—2019年杭州湾海域水质石油类含量范围分别为0.008～0.042 mg/L、0.011～0.046 mg/L、0.007～0.094 mg/L,年度平均含量分别为0.023 mg/L、0.023 mg/L和0.016 mg/L,均满足第一类海水水质标准。在季节变化上，水质中石油类指标由于受潮流、含沙量及风力等物理因素影响表现不明显，均属于低含量下的波动。在年际变化上，2017年和2018年石油类含量总体相当，2019年相比前2年有显著降低，具有一定的下降趋势。在平面分布上，主要呈现为多点源分布，高值区主要出现在嘉兴近岸和杭州湾南岸。通过相关性分析研究发现，石油类含量与悬浮物呈显著负相关，海水中悬浮物对石油类污染物有吸附作用，海水中悬浮物的质量越大，石油类含量越低。 相似文献
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根据2009年8月、2010年5月和9月3个航次的监测数据,探讨了小清河口水质污染程度及富营养化状况。结果表明:小清河口水体污染严重,DO%平均值小于80%,其中盐度小于10的区域仅为40%;DIN平均值7.00mg/L,超过二类海水标准的23倍,CODMn平均值为7.98mg/L,是二类海水标准的2.6倍。亚硝酸盐浓度偏高,平均值大于0.1mg/L,最高值达0.55mg/L。易降解有机物占总有机物的比例为30%左右。综合营养状态指数法(TLI)评价显示,小清河口盐度小于15的水体TLI值大于70,处于重度富营养级,盐度15～25之间仍为中度至轻度富营养水平。因此小清河口污染治理十分迫切,应从源头加强对小清河口污染物排放的控制。 相似文献
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于2011年5月~2012年4月对曹妃甸海域的温度、盐度、透明度、溶解氧、化学需氧量、亚硝酸盐、硝酸盐、氨氮、活性磷酸盐、总氮、总磷、叶绿素-a、叶绿素-b、油类等理化因子和营养指标进行调查,根据调查结果进行分析,揭示了该海域理化因子的时空变化规律,对海域的营养状况进行评价,为曹妃甸海域生态系统的研究积累基础资料。结果表明,调查期间该海域溶解氧含量平均值为7.93mg/L,变化范围为3.64~11.08mg/L;化学需氧量含量平均值为1.03mg/L,变化范围为0.25~3.05mg/L;无机氮含量平均值为1.24mg/L,变化范围为0.02~6.05mg/L;活性磷酸盐含量平均值为1.75×10~(-2) mg/L,变化范围为0.10×10~(-2)~5.72×10~(-2) mg/L;叶绿素-a含量的平均值为5.60μg/L,变化范围为0.49~31.17μg/L;叶绿素-b含量的平均值为1.67μg/L,变化范围为0.31~6.81μg/L;油类含量的平均值为0.119mg/L,变化范围为0.000~0.680mg/L。N:P值均大于16,属于磷限制性海域;根据潜在富营养化评价模式,营养状态质量指数法评价模式,为磷限制潜在性富营养(ⅥP)且为富营养化水平;而通过有机污染指数计算结果来看,有机污染为中度污染。 相似文献
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珠江口水域化学耗氧量(COD)的分布特征 总被引：5，自引：1，他引：4
2002年5月和8月对珠江口伶仃洋水域水质化学耗氧量（COD）进行了调查研究,结果表明：该水域近期COD含量变幅在0.41～2.72mg/L之间,平均值为1．21mg/L;区域分布呈北部向南部水域逐渐递减以及近岸水域含量大于远岸的变化趋势;夏季COD的含量高于春季：以我国Ⅰ类海水水质COD含量≤2mg／L标准评价,超标率为15％;COD含量与同期（春、夏季）的悬浮物含量呈正相关性,与无机氮和活性磷酸盐含量在夏季呈负相关性。 相似文献
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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
8.
《海洋湖沼通报》2016,(2)
东平湖是南水北调东线关键调蓄湖,其水质状况直接影响调水水质安全。考虑到冬季是调水的主要季节,课题组特于2011年12月份采集了东平湖33个点的水样,测定了营养盐的浓度以及主要水化学指标,以了解东平湖水体营养盐的污染特征和水质状况。研究表明,东平湖TN、TP平均含量分别为0~3.7mg/L、0.009~0.269mg/L,无机氮的含量大小依次为NO_3~--NNH_4~+-NNO_2~--N;东平湖湖泊的矿化度等水化学指标浓度存在一定差异,主要离子是Mg~(2+)-Ca~(2+)-Na~+-SO_4~(2+)-Cl~--HCO_3~-,水型为硫酸盐类-镁组-II型水;根据单因子法水质评价结果,东平湖水质情况已不容乐观,33处样点中有10个水质属于劣V类,7个样点的水质属于V类,主要是因为TN、TP含量超标,因此为了确保调水水质安全,需进一步加大区域及东平湖水质治理力度。 相似文献
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《海洋湖沼通报》2017,(2)
2015年4月(春季)在东昌湖沿岸均匀采集21个水样,分析了水样中氮(N)、磷(P)、总砷(As)的质量浓度,并应用美国环保局(USEPA)推荐的健康风险评价模型对东昌湖通过饮用水途径引起的水环境健康风险进行了初步评价。结果表明,水体中总氮(TN)和总磷(TP)的浓度均值分别为2.70mg/L和0.15mg/L,均高于《地表水环境质量标准》(GB 3838-2002)Ⅲ类水标准值,且超标率均为100%。总砷的含量为0.13-0.82μg/L,平均值为0.60μg/L。化学致癌物As通过饮水途径产生的健康风险平均值为3.99×10-6/a,在美国环保局(USEPA)推荐的1.0×10-6/a~1.0×10-4/a可接受区间内。由非致癌物氨氮(NH+4)和硝态氮(NO-3)产生的健康风险等级为10-11~10-10/a。东昌湖化学致癌物As健康风险值远大于非致癌物质,因此在关注湖水富营养化的同时也须对As做进一步调查。 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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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
12.
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
13.
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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《海洋学报(英文版)》2014,(9):F0003-F0003
<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, 相似文献
16.
The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance. 相似文献
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Rahul Sharma 《Marine Georesources & Geotechnology》2000,18(3):237-250
Observations on seafloor features from subbottom profiling and seabed photography data show that the undisturbed and natural conditions before the benthic disturbance undergo a substantial change after operation of the disturber. The effects can be seen in the form of deep trenches and grooves, formed by the action of the sleds and the pumping of the sediment along its path, as well as sediment piles on either side of the track. Biological traces such as fecal coils, casts, tubes, burrows, and trails get obliterated in the areas of disturbance and resedimentation. The smooth, uniform nature of the seafloor observed in predisturbance phase shows microtopographic changes in and around the disturbed area as a result of sediment excavation and resettlement. Vertical mixing as well as lateral transport of sediment alter the geological, biological, physical, and chemical conditions on the seafloor, which need to be monitored over time to assess the process and the time taken for restoration of environmental conditions. 相似文献
19.
Vance P. Vicente 《Marine Ecology》1989,10(2):179-191
Abstract. Long-term changes in the distributional patterns of commercial sponges ( Spongia spp. and Hippospongia spp.) within the West Indian Region indicates that: 1) commercial sponges had a widespread distribution throughout the whole West Indian Region and were ubiquitous in very shallow water until about the first half of the present century; 2) they were fished commercially not only in the traditional northern Caribbean sites (Florida, Gulf of Mexico, Bahamas) but also in the Greater ( e. g. , Hispaniola, Jamaica) and Lesser Antilles; and 3) they became extinct throughout most of the Lesser Antilles ( e. g. , Puerto Rico, Vieques, St. Thomas) sometime during the first half of this century. Mortalities of spongiids within the Antilles were found to differ from other marine mortalities in that: 1) species disappeared from a large region; 2) species vanished from different habitats and depths; and 3) natural populations never recovered. Species richness patterns suggest that commercial sponge genera ( Spongia and Hippospongia ) evolved under slightly cooler elimatic conditions than those found at present, and that these extinctions occurred as a direct or indirect effect of positive thermal anomalies in sea surface and atmospheric temperatures between 1900–1950. The concept that species diversity is stable on a regional scale is questioned. 相似文献
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The behaviour of an axially pre-loaded cylindrical member of an offshore structure, hit by a supply ship, has been investigated. The effects of axial pre-loading on the dynamic properties of members, the extent of damage and propagation of dynamic instability in the tubular members have also been investigated. Numerical models have been validated using available experimental data from the literature although these are mostly static with no pre-loading. Axial pre-loading was found to change the dynamic characteristics of some cylindrical members quite dramatically while it had no significant effect on others. The study examined whether there was any change in the behaviour between local and global modes when the loading was dynamic rather than static. The effect of damping on the dynamic instability of axially pre-loaded tubes under lateral dynamic loads was also studied. It was observed that for some geometries the quasi-static response can be used to define the boundary between bounded and unbounded dynamic responses. The main contribution of this study, compared with previous investigations reported in the literature, is that both pre-loading and dynamic effects have been included. 相似文献