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251.
252.
对胶州湾北岸潮间带底泥样品中三-(2,3-二溴丙基)异氰脲酸酯(tris-(2,3-dibromopropyl)isocyanurate,TBC)和六溴环十二烷(hexabromocyclododecanes,HBCDs)的3种同分异构体(α-HBCD、β-HBCD、γ-HBCD)的分布水平进行分析,结合索氏提取与Waters ACQUITY UPLC-MS-MS超高效液相色谱-质谱联用仪检测出TBC和HBCDs的3种同分异构体α-HBCD、β-HBCD、γ-HBCD,浓度范围分别为1.20~5.62 ng·g~(-1)(干重)、1.18~1.54 ng·g~(-1)(干重)、1.50~1.85 ng·g~(-1)(干重)、2.12~2.99 ng·g~(-1)(干重)。其中,TBC在河流入海口处的浓度较高,γ-HBCD占ΣHBCDs的比例(44.75%)最高,且相关性分析表明TBC和HBCDs可能有相似的污染来源。最近,斯德哥尔摩公约持久性有机污染物审查委员会(POPRC)将HBCDs列入POPs名单加以限制使用,这表明其具有一定的环境风险,未来可能对环境和人类健康造成的危害应该引起足够的重视。  相似文献   
253.
Based on biologic and environmental materials collected from coastal areas of Bohai Bay (China) in April, 2008, three biotic indices (AZTI's Marine Biotic Index (AMBI), Shannon-Wiener Index and W-statistic) were applied together to evaluate the ecological status of the sampling area. The results showed a clear spatial gradient from a worse ecological status in the near-shore areas (especially around Haihe and Jiyun River Estuaries) to a better status in the offshore areas. While all the three indices could assist decision makers in visualizing spatial changes of organic pollutants in Bohai Bay, two indices, i. e., AMBI and Shannon-Wiener index, were effective in distinguishing sites from Haihe River Estuary, Jiyun River Estuary and other area. However, W-statistic can't tell the differences between estuaries and other area. It would be explained that organic pollutants and/or other environ- mental stresses in Bohai Bay were not strong enough to reduce the size ofmacrozoobenthos, which may cause both of the abundance and biomass curves crossed. To our knowledge, this is the first time that several benthic indices were used to assess the benthic ecological status in Bohai Bay, which gave the similar results. Furthermore, there is indication that the ecological status is related to excess input of wastewater along main rivers and outlets. In a word, AMBI, Shannon-Wiener Index and W-statistic could be able to assess the benthic ecological status of Bohai Bay under the organic pollutants pressure.  相似文献   
254.
钦州湾水体中磺胺类抗生素污染特征与生态风险   总被引:1,自引:0,他引:1  
利用高效液相色谱-串联质谱(HPLC-MS/MS),研究了钦州湾近海及汇海河流磺胺类抗生素浓度和分布特征.结果表明:4种磺胺类抗生素(SAs)和甲氧苄氨嘧啶(TMP)在钦州湾近海及汇海河流均有不同程度的检出,其浓度范围为n.d.~12ng/L.其中,磺胺甲基异恶唑(SMX)在近海的检出率和平均浓度最高,分别为100%和4.1ng/L;其次为TMP(检出率87%,平均浓度1.0ng/L).与国内外其他水域相比,钦州湾磺胺类抗生素浓度处于较低水平.钦州湾近海抗生素浓度分布呈现以下趋势:茅尾海(8.4ng/L)>钦州外湾(1.9ng/L)>三娘湾(1.4ng/L).磺胺类抗生素在钦州湾的海水养殖区均呈现出较高的浓度水平,说明高密度水产养殖是钦州湾水体中抗生素的重要污染源.生态风险评价结果表明,钦州湾水体中残留的磺胺甲基异恶唑(SMX)对相应的敏感物种存在中等生态毒性风险,需引起相关部门的重视.  相似文献   
255.
It is a current challenge to better understand the relative importance of species in ecosystems, and the network perspective is able to offer quantitative tools for this. It is plausible to assume, in general, that well-linked species, being key interactors, are also more important for the community. Recently a number of methods have been suggested for quantifying the network position of species in ecological networks (like the topological importance metric, TI). Most of them are based on node centrality indices and it may happen that the two most important species in a food web have very similar interaction structure and they can essentially replace each other if one becomes extinct. For conservation considerations it is a challenge to identify species that are richly connected and, at the same time, have a relatively unique and irreplaceable interaction pattern. We present a new method and illustrate our approach by using the Kuosheng Bay trophic network in Taiwan. The new method is based on the interaction matrix, where the strength of the interaction between nodes i and j depends only on topology. By defining a threshold separating weak and strong interactors, we define the effective range of interactions for each graph node. If the overlaps between pairs of these ranges are quantified, we gain a metric expressing how unique is the interaction pattern of a focal node (TO). The combination of centrality (TI) and uniqueness (TO) is called topological functionality (TF). We compare the nodal importance rank provided by this metric to others based on a variety of centrality measures. The main conclusion is that shrimps seem to have the most unique interaction pattern despite that their structural importance has been underestimated by all conventional centrality indices. Also, our network analysis suggests that fisheries disturb the ecosystem in a more critical network position than the impingement by the local power plant.  相似文献   
256.
赤潮多发区深圳湾叶绿素a的时空分布及其影响因素   总被引:6,自引:0,他引:6  
于2008年2月至2008年11月分四个季度调查了赤潮多发区深圳湾叶绿素a的时空分布,并分析了叶绿素a与主要环境因子之间的关系.结果表明,深圳湾叶绿素a质量浓度范围为3.07~309.94 mg·m~(-3),年平均值为42.29 mg·m~(-3).四季叶绿素a平均质量浓度由高到低排列分别为:春季(108.33 mg·m~(-3))>夏季(35.2 mg·m~(-3))>秋季(16.68 mg·m~(-3))>冬季(8.96 mg·m~(-3)).叶绿素a的质量浓度在冬季和春季呈现由湾内向湾外递减的分布特征,而夏季和秋季呈现由西岸向东岸递减的分布特征,整体则呈现由湾内向湾外递减的分布特征.相关分析显示深圳湾叶绿素a与水温、COD、TOC、PO_4~(3-)-P和浮游植物密度因子显著正相关,与DIN因子极显著正相关,说明叶绿素a与水温、DIN、PO_4~(3-)-P、COD、TOC和浮游植物密度之间有着比其它因子更为密切的关系.以叶绿素a作为富营养化评价标准,发现深圳湾海域富营养化严重,存在随时爆发赤潮的潜在风险.  相似文献   
257.
厦门西港近岸沉积物重金属污染历史及源解析   总被引:7,自引:0,他引:7       下载免费PDF全文
分析厦门西港潮间带柱状沉积物中14种重金属元素(Sc、V、Cr、Co、Ni、Cu、Zn、Sr、Cd、Sb、Tl、Pb、Fe和Hg)的垂向分布特征、污染历史和污染来源.结果表明, 1795年之前,多数重金属元素含量变化趋势较平稳;1795~1849年间,Sc、Cr、Co、Ni、Cu、Sr、Cd、Tl、Pb和Hg含量有明显增加;2001~2011年间,Sc、Cr、Co、Sr、Tl、Pb和Hg含量又有增加趋势.多元统计分析结果表明,沉积柱中重金属元素主要有3大来源:交通和工业活动、自然源、工业和生活污水排放,贡献率分别是72.87%、12.20%和10.99%.柱状沉积物中铅同位素示踪分析表明,铅同位素组成从底层至表层由工业活动及污水排放逐步向机动车尾气排放漂移,厦门西港近岸海域中铅污染主要受交通和工业活动、工业和生活污水排放的影响.  相似文献   
258.
This contribution characterises the sources and distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments of the Basque coast (Bay of Biscay). Different source characterisation approaches (i.e. GIS assisted-chemometrics, PAH diagnostic ratios and analyses of composition profiles) were used in combination to successfully identify the factors determining the origin and distribution of PAHs. Urban/industrial combustion processes were identified as the main PAH source. However, the analysis of PAH composition patterns and diagnostic ratios identified secondary natural and petrogenic PAH sources on small spatial scales. The median ∑18PAH concentration ranged from 66 μg kg?1 (d.w.) to 7021 μg kg?1 (d.w.). The Ibaizabal estuary, which supports most of the anthropogenic pressure in the region (i.e. urban development, industrialisation, commercial and recreational harbours), also showed the highest PAH concentrations. On the shelf, human activities, hydrodynamic conditions and geomorphological features led to spatial differences in the PAH concentrations among sectors: the offshore and west sectors were characterised by higher concentrations, while the lowest values were found in the mid and east sectors. The results enhance the knowledge on PAH-related contamination processes and could be used to support the environmental assessment process required under current European marine legislation.  相似文献   
259.
厦门湾空气质量对新冠疫情管控的响应   总被引:1,自引:1,他引:0  
徐超  吴水平  刘怡靖  钟雪芬 《环境科学》2021,42(10):4650-4659
通过对厦门湾城市群在COVID-19封锁前后6周内(2020-01-11~2020-02-21)的空气污染物浓度变化进行分析,以确定影响本区域空气质量的主要人为污染源.在春节假期与封锁叠加期间,SO2、NO2、CO、PM10和PM2.5浓度相比于节前1周的下降幅度分别为6%~22%、53%~70%、34%~48%、47%~64%和53%~60%,而O3浓度变化没有一致的规律性;与2018~2019年历史同期相比,PM2.5、PM10、CO和NO2的下降幅度更大,但SO2的下降幅度相当;在复工复产后,NO2的反弹幅度最大(38%~138%),远高于SO2(2%~42%),显示交通源相对于固定源更易受到疫情管控的影响;春节后风速增大和降水增多也为SO2、NO2和PM的下降提供了正向影响.利用反距离插值权重法,得到管控前后厦门湾城市群不同污染物的空间分布变化特征,显示NO2浓度高值区的变化与交通源高度相关,CO和SO2空间分布特征保持稳定,复工后PM2.5和PM10在人口与路网密集区变化不明显,而在工地相对集中区域有明显上升,O3空间分布的低值区与NO2的高值区具有较好的空间匹配性,显示NO2对O3滴定作用明显,可为进一步O3污染减排措施的制定提供参考.  相似文献   
260.
基于海湾环境容量价值影响因素的分析,采用环境经济学的影子工程法,结合水动力数值模型及其与污染物扩散的耦合模型,建立了围填海导致的海湾环境容量价值损失的预测评估模型和方法,并以厦门同安湾为例,对同安湾4个围填海规划方案可能造成的环境容量价值的损失进行了预测评估.结果表明,方案1~方案4围填海面积依次为1.98,7.73,9.38,19.24km2,围填海造成的环境容量的损失依次为12281.3,48418.6,60706.6,132800.1万元/a,单位面积的损失依次为62.03,62.64,64.72,69.02元/(m2×a).围填海活动带来的环境成本不容忽视.基于评估结果,针对厦门围填海的现状提出了相关的政策建议.  相似文献   
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