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1.
来自水利部黄河水利委员会的消息,经过中国治黄人的不懈努力,黄河河口三角洲生态系统得到明显恢复和改善。权威部门编印的《中国海洋公告》显示,黄河河口三角洲生态系统已由2006年前的不健康恢复至亚健康状态。  相似文献   

2.
顺义区地下水水源地脆弱性评价   总被引:4,自引:0,他引:4  
从顺义区地下水源地的特点和实际情况出发,建立了顺义区地下水源地脆弱性综合评价指标体系,并基于该指标体系采用灰关联度评价方法对顺义区地下水源地进行脆弱性综合评价。将综合评价与固有脆弱性评价对比分析,结果表明,采用地下水水源地综合脆弱性与固有脆弱性相结合的评价方法评价结果更为科学合理,可以更好地评价顺义区地下水源地脆弱性。  相似文献   

3.
试论滨海火电厂温排水对水体富营养化的影响   总被引:2,自引:0,他引:2  
本文通过对汕头、湛江二大筹建中电厂厂址附近海域水质富营养化的调查,从水体富营养化的形成条件和影响因素入手,分析了河口医水质富营养化特征、成因和滨海火电厂温排水排放对水域富营养化的影响。文章通过分析认为,电厂大量温排水的排放,促进了水域中水生物的增殖;水中溶解氧减少和水体自净能力的下降,促进底泥中磷素的释放,使水中氮磷比例更趋于适合富营养化特征藻类的增殖需要,在某种程度上加速了富营养化的发生。最后提出了滨海火电厂海区防止“赤潮”发生的途径和新电厂选址的意见。  相似文献   

4.
生态工业园区及其建设   总被引:7,自引:0,他引:7  
生态工业园区是实现生态工业和工业生态学的重要途径,代表了未来工业生态系统发展方向。本文从生态工业园区的概念出发,分析了生态工业园区的基本特征与功能。阐述了生态工业园区的类型及其建设的重点内容。介绍了生态工业园区建设实践,提出了生态工业园区建设的对策与措施。  相似文献   

5.
海洋污染的影响是多方面的,但直接受害者是海洋生物,尤其是海洋水产业.这是因为海洋受污染,一般在河口、海湾和近海较严重.这些水域是许多重要经济鱼、贝和虾产卵、索饵和幼体生长的场所,目前世界海洋渔业捕捞量大约90%是来自大陆架水域,而海洋养殖业(包括海洋藻类、贝类、虾、鱼、以及其他海珍品的养殖)几乎都是在  相似文献   

6.
当前景观生态学,包括对农业景观生态学的发展已经突破早期对格局—空间结构的描述,达到了对景观生态系统的过程分析阶段。尽管现在关于流或过程的研究大都是经验性的,而正是这些经验性的信息积累无疑会成为未来景观生态学原理形成的基础。进一步的发展应主要依赖概念公理体系的建立和技术的改进。  相似文献   

7.
杭州西湖水生高等植物的恢复与水生生态修复   总被引:4,自引:3,他引:4  
在过去的50年,西湖一直被富营养化问题所困扰。迄今为止,采用了各种工程措施进行治理,耗资数亿,但收效不明显。为了进一步解决西湖富营养化问题,提出需要用生态方法去解决生态问题,通过生态学手段,恢复、重建高等水生植物带落,增加水生生物多样性,改善西湖水生生态系统的结构和功能,控制藻类来修复西湖水生生态系统。科学地选择先锋种类组合、消除草食性鱼类的影响、合理地控制水位是西湖水生植被恢复过程中的三个重要措施。  相似文献   

8.
《环境污染与防治》2006,28(4):307-307
联会国新千年生态系统项目(MA)已于2006年3月完成。这是迄今对全世界生态系统健康状况进行评价的最大项目,该项目于2001年由联合园秘书长安南发起,旨在为决策者提供依据,也作为公众参与的手段。95个国家的1360名专家参与评价,并有80人组成的评议团,资料来源于各国科学文献、数据库和数学摸式计算。  相似文献   

9.
微生物在苏州河生态系统中的地位及作用   总被引:3,自引:0,他引:3  
苏州河是上海的母亲河,但近年来随着上海经济的发展,苏州河的污染越来越严重。这不仅损害了上海市民的生活质量和身体健康。而且与上海国际大都市的形象格格不入。20世纪80年代,上海市政府开始治理苏州河,但从未从生态学的角度治理过苏州河。微生物作为生态系统重要组成部分-分解者,对维持苏州河生态系统的平衡起着极其重要的作用。微生物不仅能降解苏州河水体和底泥中的有机物,而且可作为水体污染程度及受污后治理恢复状况的指示指标。本文主要选取有代表性的指示微生物,通过对苏州河上海市区段8个采样段面处底泥(主要是表层底泥)中微生物指标的定量测试及代表性河段的耗氧速率测定,来了解目前苏州河的污染状况及微生物在整个生态系统中的地位和作用,从而为苏州河的综合治理提供依据。  相似文献   

10.
正确处理发展经济和维持生态平衡的关系是经济建设中的一件大事。本书根据这个宗旨由杭州大学生物系诸葛阳教授编著。内容分十二章,即生态学概述;生物与环境关系;种群和群落;生态系统的结构与功能;维护自然的生态平衡;森林的生态效益;生物资源的保护和利用;自然保护区的建设;海岛的生态特点和开发利用;环境污染与防治原则;有害动物的综合防治;环境管理的生态学基础。  相似文献   

11.
Environmental Science and Pollution Research - Adsorption-desorption behavior of ionic antibiotics in natural aquatic environment is complex, especially in coastal or estuary area where influencing...  相似文献   

12.
Persistent organic pollutants (POPs) are widespread compounds, such as organohalogenated compounds, polycyclic aromatic hydrocarbons (PAHs) and pesticides, which can be found in all types of environmental compartments. Their presence in the aquatic environment is a worldwide problem, with emphasis on sediments which act as depository and consequently as a source of hydrophobic, recalcitrant and harmful compounds. Besides, these pollutants might affect the reproduction and mortality of living organisms, diverging in their potential to bioaccumulate in tissues. The present paper aims to review the occurrence of POPs in sediments and biota from the coastal, estuarine and river areas of Portugal. The list of the studied compounds comprises organohalogenated compounds, PAHs, organometallic compounds, pesticides, sterols, fatty acids and pharmaceutical compounds. The contamination of sediments by various pollutants is presented, such as PAHs up to 7,350 ng g?1 found in Sado estuary and polychlorinated biphenyls up to 62.2 ng g?1 in the case of sediments collected in Ria de Aveiro. The occurrence of these persistent toxic substances in sediments demonstrates aquatic contamination from agricultural, industrial and urban discharges and the concern about the potential risks to aquatic organisms, wildlife and humans. In fact, several classes of POPs have also been found in biota, such as polychlorinated biphenyls up to 810.9 ng g?1 in sentinel fish from the Douro River estuary and pesticides in bivalves from the Sado River estuary. The importance of further systematic research on sediments and biota is here highlighted to compare the contamination of these two reservoirs; to assess their spatial and temporal variation; and to determine other classes of POPs that were not investigated yet (e.g., industrial compounds, estrogens and many classes of pharmaceuticals).  相似文献   

13.
Microcosm experiments have been carried out with whole natural meiobenthic communities to look at the effects of TBT sediment contamination on the community structure of the dominant nematode component of the meiobenthos. TBT has a high affinity for aquatic sediments, yet this is the first study of the effects of this contaminant in sediment on natural benthic communities. Three communities were studied from contrasting locations in south-west England: the intertidal of the Lynher estuary (muddy sediment) and the Exe estuary (sandy sediment) and the subtidal (50m depth) at Rame Head off Plymouth (muddy sand). Fresh sediment with natural meiobenthic communities was incubated for 2 months with TBT-contaminated sediment (three dose levels) in bottles. Nematodes were identified and enumerated and subjected to multivariate data analysis. The sandy Exe estuary fauna was significantly affected by TBT-contaminated sediment at all three doses (0.3, 0.6 and 0.9 microg g(-1) dry wt (as Sn) sediment), whereas the offshore fauna from Rame Head was significantly affected only at the highest dose. The muddy Lynher estuary meiofauna was affected (somewhat peculiarly) at the medium dose level only. Meiobenthic nematodes may not be as sensitive to TBT-contaminated sediment as other infaunal benthos but exhibited responses to levels of contamination still persisting in some UK estuaries and harbours. Comparing the effects of TBT with those of copper and zinc in the same laboratory experiments, our observations suggest that the relative impact of TBT on meiobenthic community structure is not as great as these contaminants in marine sediments. Although there are very few observations of TBT toxicity in sediment, it appears that TBT is toxic at much lower concentrations in seawater (ppb) than it is in sediment (ppm).  相似文献   

14.
The potential for hydrophobic organochlorine contaminants to be sequestered in submersed aquatic vegetation was evaluated by determining the concentrations of cis- and trans-chlordane, dieldrin, and polychlorinated biphenyls (PCBs) in feral aquatic macrophytes (Hydrilla verticillata (L.f.) Royle) collected from the tidal Potomac River. Similarities in mean dry-weight concentrations of the identified organochlorine compounds in H. verticillata and surrounding alluvial sediments indicated that the extent of sequestration in H. verticillata was of the same magnitude as sorption of these compounds to river sediments, but some qualitative differences in PCB congener profiles existed. The results imply that to some degree H. verticillata can influence downstream fluxes of organic contaminants in fluvial transport in the Potomac River, and, furthermore, identify this species as a viable candidate organism for hydrophobic organochlorine contaminant biomonitoring in the Chesapeake Bay estuary.  相似文献   

15.
The rapid economic development in the Pearl River Delta (PRD) region in South China in the last three decades has had a significant impact on the local environment. Estuarine sediment is a major sink for contaminants and nutrients in the surrounding ecosystem. The accumulation of trace metals in sediments may cause serious environmental problems in the aquatic system. Thirty sediment cores were collected in the Pearl River Estuary (PRE) in 2000 for a study on trace metal pollution in this region. Heavy metal concentrations and Pb isotopic compositions in the four 210Pb-dated sediment cores were determined to assess the fluxes in metal deposits over the last one hundred years. The concentrations of Cu, Pb and Zn in the surface sediment layers were generally elevated when compared with the sub-surface layers. There has been a significant increase in inputs of Cu, Pb and Zn in the PRE since the 1970s. The results also showed that different sampling locations in the estuary received slightly different types of inputs. Pb isotopic composition data indicated that the increased Pb in the recent sediments was of anthropogenic origin. The results of trace metal influxes showed that about 30% of total Pb and 15% of total Zn in the sediments in the 1990s were from anthropogenic sources. The combination of trace metal analysis, Pb isotopic composition and 210Pb dating in an estuary can provide vital information on the long-term accumulation of metals in sediments.  相似文献   

16.
疏浚对巢湖双桥河水环境容量的影响   总被引:4,自引:0,他引:4  
双桥河是巢湖受污染较为严重的入湖河流之一,其入湖口距巢湖市自来水厂取水口仅500 m,同时也是巢湖市的主要行洪河道,为了改善水质状况并提高河道行洪能力,于2010年3—5月对双桥河进行了疏浚。本文作者于2009年12月—2010年10月对双桥河监测断面及排污口进行了监测,在分析双桥河水质及现有污染源的基础上,选择CODMn、TP、NH3-N和TN作为水质敏感参数,对疏浚前后双桥河的不同河段污染物质的水环境容量进行了模拟计算,并调查了水生植被覆盖度及沉积物氮磷含量的变化。结果表明,疏浚后整个河道水生植被的覆盖度由40%降低到5%左右,各污染物的降解系数都有较大程度的降低,同时疏浚后短期内CODMn和TP的环境容量均有一定程度的降低,而NH3-N和TN的环境容量变化较小。分析认为,这一方面是由于疏浚后河道内水生植物覆盖度的降低导致水体的自净能力降低,另一方面是由于疏浚过程中的扰动引起大量沉积物的再悬浮及污染物的释放。所以在减少外来污染的前提下,对重富营养化水体底泥进行疏浚并开展水生植被恢复工程应是控制富营养化的有效途径。  相似文献   

17.
Climate change is projected to cause significant alterations to aquatic biogeochemical processes, (including carbon dynamics), aquatic food web structure, dynamics and biodiversity, primary and secondary production; and, affect the range, distribution and habitat quality/quantity of aquatic mammals and waterfowl. Projected enhanced permafrost thawing is very likely to increase nutrient, sediment, and carbon loadings to aquatic systems, resulting in both positive and negative effects on freshwater chemistry. Nutrient and carbon enrichment will enhance nutrient cycling and productivity, and alter the generation and consumption of carbon-based trace gases. Consequently, the status of aquatic ecosystems as carbon sinks or sources is very likely to change. Climate change will also very likely affect the biodiversity of freshwater ecosystems across most of the Arctic. The magnitude, extent, and duration of the impacts and responses will be system- and location-dependent. Projected effects on aquatic mammals and waterfowl include altered migration routes and timing; a possible increase in the incidence of mortality and decreased growth and productivity from disease and/or parasites; and, probable changes in habitat suitability and timing of availability.  相似文献   

18.
Estuarine areas represent complex and highly changing environments at the interface between freshwater and marine aquatic ecosystems. Therefore, the aquatic organisms living in estuaries have to face highly variable environmental conditions. The aim of this work was to study the influence of environmental changes from either natural or anthropogenic origins on the physiological responses of Mytilus edulis. Mussels were collected in the Vilaine estuary during early summer because this season represents a critical period of active reproduction in mussels and of increased anthropogenic inputs from agricultural and boating activities into the estuary. The physiological status of the mussel M. edulis was evaluated through measurements of a suite of biomarkers related to: oxidative stress (catalase, malondialdehyde), detoxication (benzopyrene hydroxylase, carboxylesterase), neurotoxicity (acetylcholinesterase), reproductive cycle (vitelline, condition index, maturation stages), immunotoxicity (hemocyte concentration, granulocyte percentage, phagocytosis, reactive oxygen species production, oxidative burst), and general physiological stress (lysosomal stability). A selection of relevant organic contaminant (pesticides, (polycyclic aromatic hydrocarbons, polychlorobiphenyls) was measured as well as environmental parameters (water temperature, salinity, total suspended solids, turbidity, chlorophyll a, pheopigments) and mussel phycotoxin contamination. Two locations differently exposed to the plume of the Vilaine River were compared. Both temporal and inter-site variations of these biomarkers were studied. Our results show that reproduction cycle and environmental parameters such as temperature, organic ontaminants, and algal blooms could strongly influence the biomarker responses. These observations highlight the necessity to conduct integrated environmental approaches in order to better understand the causes of biomarker variations.  相似文献   

19.
The silica deficiency hypothesis holds that increases of still waters caused by hydraulic alterations and high nitrogen (N) and phosphorus (P) discharges enhance the growth of freshwater diatoms, which take up the dissolved silicate (DSi) supplied by natural weathering. The consequent decrease in the DSi supply to the sea is advantageous to flagellates (nonsiliceous and potentially harmful) but not to diatoms (siliceous and mostly benign) in coastal marine ecosystems. Verification of this hypothesis has been hampered by lack of relevant data, particularly in Asia. We investigated the aquatic continuum composed of Lake Biwa, the Yodo River, and the Seto Inland Sea, Japan, where the natural conditions make the silica deficiency less likely to emerge due to the inherently rich supply of DSi. The results showed that the silica was retained both in the lake and nearby the estuary. The relative dominance of diatom and flagellates could not be explained solely by the stoichiometric arguments but by the supportive discussion on the difference of their behavioral characteristics and the process nearby the estuary, where direct inputs of N and P and effluent Si enhanced diatom bloom, even though the Si/N ratio was lowered in the upstream reservoir. Thus the retention of DSi occurred in two places: in the lake and nearby the estuary, where the other N and P are loaded directly. The rate of DSi retention correlated with socio-economic changes, such as rapid economic growth in the 1960s and mitigations implemented after the 1980s. Sensitivity of this continuum to the Si processes suggests the global significance of this hypothesis.  相似文献   

20.
Analysis of Perfluorooctane sulfonate (PFOS) distribution in water and sediment in Yangtze River Estuary showed that the estuary was a sink for PFOS. Salinity was an important parameter in controlling the sediment-water interactions and the fate or transport of PFOS in the aquatic environment. As the salinity (S‰) increased from 0.18 to 3.31, the distribution coefficient (Kd) between sediment and water linearly increased from 0.76 to 4.70 L g−1. The study suggests that PFOS may be carried with the river water and transported for long distances before it reaches to the sea and largely scavenged to the sediment in the estuaries due to the dramatic change in salinity.  相似文献   

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