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1.
以太湖不同营养水平湖区为研究对象,采用改进的砷(As)形态连续提取法对表层沉积物中As的化学形态进行分析研究,探讨了沉积物中总砷(TAs)和As形态的分布特征及其与沉积物中营养盐和总有机碳(TOC)的相关性,并利用潜在生态风险评价(Eir)和风险指数编码法(RAC)评估了各湖区沉积物中As的生态风险水平.结果表明,各湖区表层沉积物中TAs的平均含量约为14.23~16.59 mg·kg~(-1),其中,竺山湾的TAs平均含量相对最高.As形态表现出明显的空间分布特征,其中,北部富营养湖区(竺山湾、梅梁湾、贡湖湾)中的有效态As(非专性吸附态和专性吸附态)与潜在有效态As(无定形氧化铁结合态、晶体形氧化铁结合态、有机结合态)的含量与百分比均高于中营养水平的南太湖,而北部湖区的残渣态As含量则低于南太湖.Pearson相关分析结果显示,除晶体形氧化铁结合态As和残渣态As外,沉积物总氮(TN)、总磷(TP)和TOC与其他As形态均存在显著的正相关关系.潜在生态风险评价结果表明,各湖区沉积物TAs均处于低风险;而RAC评价结果表明,各湖区沉积物的有效态As基本处于中等风险水平,且北部湖区的RAC指数均明显高于南太湖.  相似文献   

2.
The magnitude of the compensatory response inherent to fish population seems to be questioned with each new generation of scientists and regulators. The major reason for this is the demand by some that compensation be completely understood at the process level before compensation can be factored into population predictions. We first discuss several lines of evidence for the existence of compensation, and the reasons why compensation is so difficult to measure at the process level. We then offer life history theory as a general framework for improving our understanding of the likely magnitude of compensation in fish population dynamics. We use detailed, individual-based models and field data for yellow perch-walleye, striped bass, and a lake community to illustrate the complexity of compensation, and to show that predictions for a particular population require site-specific information. Analyses show that the life stage and magnitude of density-dependence can vary for different populations of the same species, and that population responses can depend on the arrangement of the food web. We must stop reinventing the density-dependence wheel; too many resources (both natural and monetary) are at stake. We suggest using three approaches for addressing the compensation issue: (1) life history theory for providing a sound basis for qualitatively understanding fish population dynamics and the magnitude of compensation; (2) age- and stage-structured matrix models for screening-level analyses to identify populations that may be at unacceptable risks of decline and therefore require additional analyses; and (3) individual-based models for better understanding the complexities of compensation at the process level and for impact assessment of at-risk, well-studied populations.  相似文献   

3.
用电感耦合等离子体发射光谱仪(ICP-OES)测定剑湖表层及柱状沉积物钒(V)含量,采用改进BCR连续提取法提取V各形态,并对V空间分布特征和生态风险进行了分析,揭示了粒度对剑湖沉积物V及形态含量的影响.结果表明,剑湖表层沉积物和柱状沉积物颗粒均以粉砂粒和细砂为主,细颗粒V含量更高.表层沉积物V含量为(117.82±63.31)mg/kg,其水平空间分布差异较大.V可交换态、可还原态、可氧化态和残渣态含量分别为(8.91±8.91),(18.36±10.53),(7.67±7.67),(80.22±58.71)mg/kg,主要以残渣态形式存在,且黏粒和粉砂粒对V可还原态和残渣态影响较大.V垂直分布差异大,底层V含量高于表层,少部分区域受黏粒和粉砂粒影响.剑湖沉积物V污染程度小,大部分地区潜在生态风险较低,底层沉积物污染程度和潜在生态风险都高于表层.  相似文献   

4.
Mercury is an important pollutant, released into aquatic ecosystems both naturally and by anthropogenic action. This element is transferred to aquatic organisms in different ways, causing potential health risks. In addition, mercury can be accumulated by humans, especially through the consumption of contaminated food. This systematic review aims to present mercury pathways, the major routes through which this element reaches the aquatic environment and its transformations until becoming available to living animals, leading to bioaccumulation and biomagnification phenomena. The key biotic and abiotic factors affecting such processes, the impact of mercury on animal and human health and the issue of seafood consumption as a source of chronic mercury contamination are also addressed. A total of 101 articles were retrieved from a standardized search on three databases (PubMed, Emabse, and Web of Science), in addition to 28 other studies not found on these databases but considered fundamental to this review (totaling 129 articles). Both biotic and abiotic factors display fundamental importance in mediating mercurial dynamics, i.e., muscle tropism, and salinity, respectively. Consequently, mercurial contamination in aquatic environments affects animal health, especially the risk of extinction species and also on human health, with methylmercury the main mercury species responsible for acute and chronic symptomatology.  相似文献   

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7.
Seeing the world through a new sense: electroreception in fish   总被引:1,自引:0,他引:1  
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8.
为掌握东洞庭湖长江江豚种群动态分布规律及其与鱼类资源的相关关系,2012年6月~2017年12月,对东洞庭湖进行了54次长江江豚种群调查和8次水声学鱼类资源空间分布调查.调查结果显示:(1)共发现长江江豚1110头次,分布在湘阴-洞庭大桥之间长约65km的区域内;(2)100% MCP)、95% MCP、75% MCP和50% MCP下,长江江豚栖息地面积依次为161.3、114.26、76.95和64.31km2,占保护区总面积百分比依次为24.18%、17.13%、11.54%和9.63%;(3)不同水位条件下,长江江豚观测群次和头次差异显著,枯水期可观测到群次和头次最高,分别为(13.92±4.64)群次/次和(31.92±7.17)头次/次,丰水期观测群次和头次最低,分别为(5.17±1.64)群次/次和(17.25±7.46)头次/次;(4)水声学调查结果显示,2013年3月东洞庭湖鱼类资源平均密度最高为57.21尾/1000m3,东洞庭湖鱼类密度与水位呈弱负相关关系,相关系数r=-0.601(P>0.05);(5)GIS模型分析结果显示,东洞庭湖鱼类资源低水位时期(枯水期和退水期后期),集中分布于扁山至鲶鱼口区域,高水位时期,东洞庭湖鱼类资源分布较为分散;(6)方差分析结果显示,东洞庭湖低水位期鱼类资源水平密度分布不均,扁山至煤炭湾区域鱼类资源水平空间平均密度最高,与其它区域有显著性差异(P<0.05),高水位时期鱼类分布较为均匀,方差分析显示,除煤炭湾至鹿角区域与城陵矶至洞庭大桥区域和扁山至煤炭湾区域分别有显著差异之外(P<0.05),其他水域之间无显著性差异(P>0.05);(7)Pearson相关性分析显示长江江豚头次与对应的鱼类密度呈显著正相关,R2=0.86,P<0.01,长江江豚可能具有随鱼群迁徙的行为特征.  相似文献   

9.
Coastal fisheries provide staple food and sources of livelihood in Pacific Island countries, and securing a sustainable supply is recognised as a critical priority for nutrition security. This study sought to better understand the role of fish for Pacific Island communities during disasters and in disaster recovery. To evaluate community impacts and responses after natural disasters, focus group discussions were held with men and women groups at ten sites across Shefa, Tafea, Malampa and Sanma provinces in Vanuatu. The combined impacts of category 5 Tropical Cyclone Pam (TC-Pam) in March 2015 and prolonged El-Niño induced drought have had a profound impact across much of Vanuatu. Terrestrial systems had been disproportionately impacted with substantial shortages in drinking water, garden crops, cash crops and damage to infrastructure. Localized impacts were noted on marine environments from TC-Pam and the drought, along with an earthquake that uplifted reef and destroyed fishing grounds in Malampa province. Communities in Malampa and Shefa provinces also noted a crown-of-thorns outbreak that caused coral mortality. The significant reduction in terrestrial-based food and income generation capacity generally led to increased reliance on marine resources to cope and a shift in diets from local garden food to rice. However, limited market access, lack of fishing skills and technology in many sectors of the community reduced the capacity for marine resources to support recovery. A flexible management approach allowed protected areas and species to be utilized as reservoirs of food and income when temporarily opened to assist recovery. These findings illustrate that fish and fisheries management is at the center of disaster preparedness and relief strategies in remote Pacific Island communities. High physical capital (e.g. infrastructure, water tanks and strong dwellings) is key for disaster preparedness, but supporting community social capital for the purpose of natural resource management and human capital for diverse adaptation skills can also improve community resilience. Recognizing the humanitarian value that well managed fisheries resources and skilled fishers can play to disaster relief adds another dimension to the imperative of improving management of coastal fisheries and aligning policies across sectors.  相似文献   

10.
为全面了解青岛市公众家电消费观及对废弃家电循环利用的认知和态度,采用问卷调查和随机采访的方法分析研究了大量调研数据和系统信息。结果表明,消费者家电消费观比较理性;对绿色家电产品和废弃家电循环利用的了解和认识比较有限,但对废弃家电分类处置却持有积极的态度和行为。大多数居民能主动将其简单分为几类:直接销售给家电回收二手市场或走街串巷的流动商贩、在线网站交易和拍卖、以旧换新交给生产厂家或销售店面、闲置于家中和赠送亲朋好友或农村希望工程。此外,消费者对废弃家电循环利用的认知度与其教育水平直接相关,而对环境和资源保护的行为与其年龄直接相关。  相似文献   

11.
Monocyclic aromatic hydrocarbons (MAHs) and polycyclic aromatic hydrocarbons (PAHs)are both well known as hazardous air pollutants and also important anthropogenic precursors of tropospheric ozone (O3) and secondary organic aerosols (SOA).In recent years,there have been intensive studies covering MAHs emission from various sources and their behavior under stimulated photochemical conditions.Yet in-situ measurements of PAHs presence and variations in ambient air are sparse.Herein we co...  相似文献   

12.
This study aimed to evaluate the spatial and temporal variations of molybdenum (Mo) in the downstream water body of a Mo mine during three hydrologic periods (wet, dry and medium seasons). The physical properties in Luhun Reservoir reflected seasonal variations in different hydrological periods. The redox potential (ORP) and dissolved oxygen (DO) increased in the dry season. The concomitant decrease in temperature (T), conductivity (COND) and total dissolved solids (TDS) were lowest in the wet season. The pH value did not change significantly during the three hydrologic periods. The distribution of Mo in the dry season was high in upstream and low in downstream areas, which was significantly different from that of the wet and medium seasons. The total Mo concentration in wet (150.1 µg/L) and medium season (148.2 µg/L) was higher than that in the dry season, but the TDS (288.3 mg/L) and the percentage dissolved Mo (81.3%) in overlying water was lowest in the wet season. There was no significant relationship between the dissolved Mo and the total Mo with TDS. In the dry season, the mean total Mo concentration was 116.3 µg/L, which was higher than the standard limit value (70 µg/L) for drinking water (US EPA-United States Environmental Protection Agency recommended value 40 µg/L). Non-point source pollution is the main characteristic of mining area pollution, which was closely related to rainfall. Thus, the Luhun Reservoir contains substantial Mo pollution, which was a significant concern given that it is used as a source of drinking and irrigation water.  相似文献   

13.
This two-part paper considers the complementarity between adaptation and mitigation in managing the risks associated with the enhanced greenhouse effect. Part one reviews the application of risk management methods to climate change assessments. Formal investigations of the enhanced greenhouse effect have produced three generations of risk assessment. The first led to the United Nations Intergovernmental Panel on Climate Change (IPCC), First Assessment Report and subsequent drafting of the United Nations Framework Convention on Climate Change. The second investigated the impacts of unmitigated climate change in the Second and Third IPCC Assessment Reports. The third generation, currently underway, is investigating how risk management options can be prioritised and implemented. Mitigation and adaptation have two main areas of complementarity. Firstly, they each manage different components of future climate-related risk. Mitigation reduces the number and magnitude of potential climate hazards, reducing the most severe changes first. Adaptation increases the ability to cope with climate hazards by reducing system sensitivity or by reducing the consequent level of harm. Secondly, they manage risks at different extremes of the potential range of future climate change. Adaptation works best with changes of lesser magnitude at the lower end of the potential range. Where there is sufficient adaptive capacity, adaptation improves the ability of a system to cope with increasingly larger changes over time. By moving from uncontrolled emissions towards stabilisation of greenhouse gases in the atmosphere, mitigation limits the upper part of the range. Different activities have various blends of adaptive and mitigative capacity. In some cases, high sensitivity and low adaptive capacity may lead to large residual climate risks; in other cases, a large adaptive capacity may mean that residual risks are small or non-existent. Mitigative and adaptive capacity do not share the same scale: adaptive capacity is expressed locally, whereas mitigative capacity is different for each activity and location but needs to be aggregated at the global scale to properly assess its potential benefits in reducing climate hazards. This can be seen as a demand for mitigation, which can be exercised at the local scale through exercising mitigative capacity. Part two of the paper deals with the situation where regional bodies aim to maximise the benefits of managing climate risks by integrating adaptation and mitigation measures at their various scales of operation. In north central Victoria, Australia, adaptation and mitigation are being jointly managed by a greenhouse consortium and a catchment management authority. Several related studies investigating large-scale revegetation are used to show how climate change impacts and sequestration measures affect soil, salt and carbon fluxes in the landscape. These studies show that trade-offs between these interactions will have to be carefully managed to maximise their relative benefits. The paper concludes that when managing climate change risks, there are many instances where adaptation and mitigation can be integrated at the operational level. However, significant gaps between our understanding of the benefits of adaptation and mitigation between local and global scales remain. Some of these may be addressed by matching demands for mitigation (for activities and locations where adaptive capacity will be exceeded) with the ability to supply that demand through localised mitigative capacity by means of globally integrated mechanisms.  相似文献   

14.
焦化场地内外土壤重金属空间分布及驱动因子差异分析   总被引:1,自引:5,他引:1  
顾高铨  万小铭  曾伟斌  雷梅 《环境科学》2021,42(3):1081-1092
焦化场地作为典型的工业污染场地,其特征污染物重金属严重危害人体健康,研究其场地内外污染物的空间分布及驱动因子,对于后续的采样设计、风险评估、污染防控等工作具有重要指导意义.本研究基于反距离加权法分析某在产焦化厂内部及外部的重金属As、Cd、Cr、Cu、Hg、Ni、Pb和Zn的空间分布,并利用地理探测器分析焦化厂内部及外...  相似文献   

15.
通过研究不同来源霾颗粒物对大鼠气管上皮细胞(RTE cells)电阻抗变化和细胞自噬因子的影响,评价不同来源霾颗粒物对人体健康风险的差异性.分别将RTE暴露于从居民区(I),高架交通源(Ⅱ)和化工园区(Ⅲ)采集的3种雾霾颗粒物中,统一暴露浓度和时间分别为100mg/L和24h.通过电子细胞基质阻抗检测(ECIS)细胞增长引起的阻抗变化和细胞电损伤恢复时间;通过蛋白免疫印迹测定p62,Atg5,Atg7,Beclin1,LC3B和mTOR蛋白表达量来分析比较不同来源雾霾颗粒物对RTE细胞自噬的影响.结果表明,与空白对照组相比,不同雾霾颗粒物处理组细胞电损伤恢复时间分别延长了34.6%,63.2%和78.0%;p62蛋白表达量差异显著性下降,Atg5,Atg7,Beclin1,LC3B蛋白表达量差异显著性上升.此外,mTOR相关蛋白表达量差异显著性下降,分别下降了4.38%,3.34%和2.36%;p-mTOR蛋白表达量与空白组相比,实验组I下降24.2%,实验组Ⅱ下降37.0%,实验组Ⅲ下降60.9%.由以上结果可知,不同来源雾霾颗粒物对RTE细胞均有一定的毒性损伤作用,能够减小细胞增长速度和削弱细胞修复能力,增强细胞自噬因子蛋白的表达,且化工园区采集的雾霾颗粒物毒性强于居民区和高架交通源.不同来源雾霾颗粒物的细胞毒性存在明显差异,基于细胞电损伤恢复时间的测定以及自噬相关蛋白的检测方法能够为雾霾颗粒物健康风险评价提供一种快速的生物学手段.  相似文献   

16.
韦燕莉  鲍恋君  巫承洲  曾永平 《环境科学》2014,35(10):3821-3829
为探讨快速城市化区域杀虫剂的分布特征,19种被忽视的杀虫剂,即苯基吡唑类(氟虫腈)、氯丹、硫丹、九氯、六氯苯、七氯、狄氏剂、艾氏剂、异狄氏剂、甲氧滴滴涕及其代谢产物被用来分析在珠江三角洲(珠三角)及其周边区域229个土壤样品中的浓度水平和空间分布.结果表明,高浓度的杀虫剂主要集中在珠三角中心地区,而低浓度的杀虫剂则分布在珠三角周边区域,这个分布模式与国民生产总值和人口密度的分布相似,表明社会经济因素对杀虫剂的分布有一定的影响.此外,在城市化发展进程中,土地使用类型的转变也可能会导致原城镇农耕地变成现城市居民区,从而使得禁用农药在珠三角中心区域浓度高.来源分析表明在珠三角及其周边区域土壤存在工业氯丹的新输入源.氟虫腈由于半衰期比较短,在很大部分的土壤样品中转化成了氟虫腈砜和氟虫腈硫醚.对土壤中19种杀虫剂进行人体风险评估发现,6个在高人口密度区域收集的样品对人体有潜在的致癌或非致癌风险.因此这些被忽视的杀虫剂在将来环境研究中需要引起关注.  相似文献   

17.
The composition of phytoplankton and the dynamics of phytoplankton and bacterioplankton biomass (PB and BB, respectively) of Sanya Bay, South China Sea, were determined. A total of 168 species (67 genera) phytoplankton were identified, including Bacillariophyta (diatom, 128 species), Pyrrophyta (35 species), Cyanophyta (3 species), and Chrysophyta (2 species). Annual average abundance of phytoplankton was 1.2 × 107 cells/m3, with the highest abundance in autumn, and the lowest in summer. Annual average dive...  相似文献   

18.
In this article, industrial ecology is used as a framework for analysing transport energy and its implication for products. The importance of the energy use for transport in a natural resource production system is analysed. By using fish as a case study, it is shown that the amount of energy for transport is highly dependent on the transport mode used. When applying industrial ecology principles for making assessments of the environmental impacts of products, the whole product chain is examined. This is an extended life-cycle approach, which also includes the transport of the finished products from the exporter to the importing country. This last part of the transport chain can be extremely energy demanding, as is shown for the case of fish transport. This finding has implications for the products, and for the form in which the products should be transported. Increasing the energy efficiency of production systems is an important industrial ecology principle, and must be taken into consideration when analysing product chains. A revision of today's practice of transporting large quantities of fresh whole fish by transcontinental airliners is bound to be necessary. This is a consequence of the demands for increased energy efficiency of tomorrow's industrial production systems.  相似文献   

19.
利用固相萃取联合液相色谱-质谱法对珠三角河流饮用水源中的21种糖皮质激素(GCs)和3种盐皮质激素(MCs)进行了研究.结果发现,24种目标物在水源水中均有检出,检出率在8%(可的松)~75%(地夫可特)之间,总浓度(∑CSs)(平均值/中值)为0.29~8.7ng/L(2.6ng/L/1.6ng/L),污染以布地奈德、丙酸氯倍他索、醛固酮为主.东江东莞段和流溪河下游水源水中肾上腺皮质激素(CSs)浓度水平总体高于西江和北江,各水源地的CSs组成与浓度存在一定的季节性差异.冗余分析发现,水源水中大部分CSs与水温、电导率、pH值以及溶解氧呈负相关关系,表明这些环境因子是影响CSs含量分布的重要因素.CSs在珠三角河流水源地的危害指数(HI)(平均值/中值)在<0.1~0.65(0.25/0.29)之间,总体处于中低风险水平.  相似文献   

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移动源排放VOCs特征及臭氧生成潜势研究—以兰州市为例   总被引:4,自引:0,他引:4  
高浓度近地面臭氧(O_3)污染是国内外许多城市面临的大气污染问题,且近年来O_3浓度呈逐渐升高的趋势.随着城市规模日益扩大,移动源成为VOCs的主要排放源之一,对移动源的O_3生成潜势进行评估,并识别其关键物种和重点污染区域,可为城市O_3控制对策的制定提供科学依据.本文以兰州市移动源为例,结合排放系数、交通流量及相关统计数据,建立兰州市VOCs移动源排放清单,并使用最大增量反应活性(MIR)估算移动源VOCs的臭氧生成潜势(OFP).结果表明,兰州市汽油车是移动源中最主要的OFP贡献源类,占移动源的71.12%;烯烃和芳香烃为移动源总OFP主要的贡献者,主要贡献物种为:乙烯、丙烯、甲醛、3-甲基-1-丁烯、甲苯、正丁烯、乙炔、间二甲苯、1,2,4-三甲基苯、邻二甲苯,这10个物种的OFP占移动源总OFP的67.29%;根据兰州市移动源VOCs排放的OFP贡献空间分布结果,移动源VOCs排放的重点控制区域为城关区和七里河区.  相似文献   

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