Investigating freshwater periphyton community response to uranium with phospholipid fatty acid and denaturing gradient gel electrophoresis analyses

Periphyton communities can be used as monitors of ecosystem health and as indicators of contamination in lotic systems. Measures of biomass, community structure, and genetic diversity were used to investigate impacts of uranium (U) exposure on periphyton. Laboratory exposures of periphyton in river water amended with 238U were performed for 5 days, followed by 2 days of U depuration in unamended river water. Productivity as measured by biomass was not affected by concentrations up to 100 microg238U L(-1). Phospholipid fatty acid (PLFA) profiles and denaturing gradient gel electrophoresis (DGGE) banding patterns revealed no changes in community or genetic structure related to U exposure. We suggest that the periphyton community as a whole was not significantly impacted by exposures of 238U up to a concentration of 100 microgL(-1). These findings have significance for the assessment and prediction of U impacts on aquatic ecosystems.     

丹江口水源区水生态功能一二级分区研究

水生态功能分区是实现流域水环境"分区、分级、分类、分期"管理的基础。以高程、干燥度及年均径流深为一级分区指标,土地利用、土壤类型、坡度、人均GDP为二级分区指标,将丹江口水源区分为6个一级水生态功能区和19个二级水生态功能区。比较不同分区的水生境状况及底栖动物种群结构特征,发现一级分区间的水生境状况与底栖动物种群结构均存在差异,二级分区之间虽然有部分生境指标较为接近,但底栖动物种群结构差异明显,证明了分区方案的科学性和合理性,为水源区的生态系统保护和水资源管理提供了依据。     

人工重建的水生植物群落演替动态研究

水生植物群落在湖泊生态修复过程中作用显著，但目前人工重建的水生植物群落抗外界干扰能力弱，群落稳定性差，这就需要我们对人工重建的水生植物群落结构及其演替的生态学过程进行研究，从而探索受损群落的修复途径。于2003年在富营养化水体中采用物理生态工程进行了水生植物群落的重建研究，对群落演替动态变化过程进行了持续3年的观测。结果表明：水生植物之间发生生态位重叠时，其结果往往是以一个物种取代另一个物种，随着生态位重叠程度下降，种间关系和群落结构趋于稳定；而当物种空间位置错开时，生长期相近的物种共存则变为可能，因此在群落的构建过程中应当避免同时引入生态位重叠较高的物种，应注意植物间时间序列及空间结构的分离；此外还通过物种间的竞争表现，对几种常见水生植物构建的群落稳定性做了初步探讨.     

Effects of atrazine and nicosulfuron on freshwater microalgae

Growth modifications caused by various concentrations of atrazine and nicosulfuron were monitored in closed and continuous culture of Chlorella vulgaris (chlorophyta), Navicula accommoda (diatomophyta), and Oscillatoria limnetica (cyanophyta). The concentration at which algal growth rate was reduced twofold (EC50) was determined in the three species for both herbicides. Comparatively, the two toxicants were applied at 10 microg/l level in microcosms inoculated with natural phytoplankton from Lake Geneva. The relative abundances of major phytoplanktonic species were measured by algal cell count at the beginning and at the end of each experiment. Atrazine and nicosulfuron have different targets in plant metabolism, respectively, photosystem II (PSII) and acetolactate synthase (ALS), and the expected effects were different. Generally, the cultured phytoplankton exhibited various sensitivities, depending on species or herbicide. In the microcosms, the major taxa of natural phytoplanktonic samples exhibited various patterns, from acute toxicity to growth enhancement. For example, the diatoms inside the community were not affected by atrazine and nicosulfuron, except for Stephanodiscus minutulus that was sensitive to both, and Asterionella/formosa that was sensitive only to nicosulfuron. The specific physiology and the relationships among the phytoplanktonic communities have to be carefully considered when one would try to predict the extent of herbicide action on natural phytoplankton using in vitro tests. There is a need to test the toxic effect on various cultured strains, representative of most of the taxonomic composition of natural communities, to take into account the wide range of sensitivities and reaction to herbicide contamination. But this is not enough to give a solid frame when transposing the results to the field, and the use of more ecologically relevant systems is recommended.     

水文连通性对湖泊生态环境影响的研究进展

水文连通性对湖泊水资源调节、水质净化和生态安全等具有重要作用，但同时也可能带来潜在风险。因而厘清水文连通性对其生态环境的影响规律，对于开展水文连通性修复工作具有重要指导意义。基于广泛的文献调研，介绍了水文连通性的定义与内涵，分别综述了水文连通性对湖泊水文水动力、水质、水生态系统影响的研究进展。在此基础上，总结归纳了水文连通性通过改变水文水动力过程影响生态系统的路径：一是直接改变生境面积、植被格局和生物迁移繁殖特征，二是通过改变水质和沉积物特征而作用于生物的生长发育及其体内污染物累积转化过程。最后，对水文连通性变化的生态环境效应研究进行了展望：(1)加强对垂向连通性的研究以及拓展不同维度连通性耦合转化研究；(2）借助水动力-水质-水生态耦合模型研究水文连通性变化下的生态环境效应；(3）开展水文连通性的生态环境风险研究，并基于生态环境效益和社会经济效益权衡确定适宜的水文连通性。     

Aquatic mosses as a monitoring tool for 137Cs contamination in streams and rivers-a field study from central southern Norway

Mosses are frequently used as biomonitors for trace element pollution in the aquatic environment. The purpose of this study was to assess their usefulness as a tool in monitoring and in regional surveys of radioactive contamination. Specimens of the aquatic mosses, Fontinalis antipyretica and F. dalecarlica, were transplanted from non-contaminated areas to streams and rivers in the Norwegian Jotunheimen Mountains and neighbouring lowland areas that had received radioactive fallout after the Chernobyl accident. Equilibrium concentrations of 137Cs in the exposed mosses were reached after a few weeks. Two series from 20 streams in 1994 and 1996 show linear correlations between activities in water and moss samples and biomagnification ratios of 10(4) - 10(5). We conclude that mosses are better suited for monitoring purposes than water samples, because they provide values integrated over weeks while the radioactivity in surface waters can be subject to rapid variations according to hydrological events. The activity concentrations in aquatic mosses can be easily measured with good precision even when aqueous concentrations are below the limit of detection. Use of aquatic mosses also reduces the logistic problems of transporting large volumes of water, especially in areas inaccessible by road.     

基于层次分析法的城市河流生态修复评估

城市的发展改变了许多河流的自然水文环境，并导致河流生态系统中水质、物理生境和生物完整性下降。评估受损河流水体修复的效果，需要结合物理、化学的参数，以及对生物结构、多样性和过程的影响。构建了包含河流水力、水质、水生生物、河岸带及物理结构5个方面15个指标的城市河流生态修复评估指标体系，运用群组决策的层次分析法(AHP)，确定了各指标的权重，重要性排序前5位依次为：水质污染指数、鱼类IBI、水源补给量、藻类多样性、透明度。并以我国南方城市岐江河整治修复状况为例进行综合评价，结果表明,河流生态系统修复评估结果为可以接受，体现了河流整治工程使河流水质、生态的状况有所改善，但河流生态系统恢复需要较长的周期，修复初期生态系统仍处于受损状态。〖     

Acute toxicity of herbicides to freshwater fish and midge larvae, Chironomus tentans

Acute toxicity of three herbicides, tafazine, bladex, and aresin, were studied for three species of freshwater teleost, namely, Labeo rohita, Mystus vittatus, and Cirrhinus mrigala, and benthic macroinvertebrate, midge larvae, Chironomus tentans, L. rohita and C. mrigala were found susceptible to all three herbicides as compared to M. vittatus and C. tentans, which were more susceptible to the tafazine toxicity. The toxicity of the three herbicides was in order of tafazine>bladex>aresin. Investigation leads to the conclusion that some herbicides, though quickly degradable, form hazards for aquatic life even at very low levels. Their application must be monitored to prevent aquatic pollution.     

鄱阳湖水生植被30年演变及其驱动因素分析

基于1983和2013年两次鄱阳湖综合科学考察植被调查结果发现，30年来鄱阳湖水生植被呈退行性演变。主要体现在：（1）水生植被面积大幅缩减，沉水植被面积减少37.7%，菱等敏感物种面积减幅为87.6%；（2）群落结构简单化，组成物种由5～8种下降至3～5种，苦草替代竹叶眼子菜成为优势物种；（3）生物多样性降低，单位面积生物量减少。驱动此演变的主要因素包括：（1）长期持续的低枯湖水位压缩了水生植物的生存空间；（2）湖水氮磷浓度增加恶化沉水植被的生境；（3）洪水灾害干扰沉水植物正常生长发育，诱发沉水植被演替；（4）过度的人类活动直接或间接损害沉水植被。为了遏制退行性演变趋势、保护湿地植被生态系统的健康，建议采取有力的湖泊管理措施，将人类活动控制在湿地生态系统可承受范围之内。     

An overview on the advanced oxidation processes applied for the treatment of water pollutants defined in the recently launched Directive 2013/39/EU

Environmental pollution is a recognized issue of major concern since a wide range of contaminants has been found in aquatic environment at ng L^− 1 to μg L^− 1 levels. In the year 2000, a strategy was defined to identify the priority substances concerning aquatic ecosystems, followed by the definition of environmental quality standards (EQS) in 2008. Recently it was launched the Directive 2013/39/EU that updates the water framework policy highlighting the need to develop new water treatment technologies to deal with such problem. This review summarizes the data published in the last decade regarding the application of advanced oxidation processes (AOPs) to treat priority compounds and certain other pollutants defined in this Directive, excluding the inorganic species (cadmium, lead, mercury, nickel and their derivatives).The Directive 2013/39/EU includes several pesticides (aldrin, dichlorodiphenyltrichloroethane, dicofol, dieldrin, endrin, endosulfan, isodrin, heptachlor, lindane, pentachlorophenol, chlorpyrifos, chlorfenvinphos, dichlorvos, atrazine, simazine, terbutryn, diuron, isoproturon, trifluralin, cypermethrin, alachlor), solvents (dichloromethane, dichloroethane, trichloromethane and carbon tetrachloride), perfluorooctane sulfonic acid and its derivatives (PFOS), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), nonylphenol and octylphenol, as well as the three compounds included in the recommendation for the first watch list of substances (diclofenac, 17-alpha-ethinylestradiol (EE2) and 17-beta-estradiol (E2)). Some particular pesticides (aclonifen, bifenox, cybutryne, quinoxyfen), organotin compounds (tributyltin), dioxins and dioxin-like compounds, brominated diphenylethers, hexabromocyclododecanes and di(2-ethylhexyl)phthalate are also defined in this Directive, but studies dealing with AOPs are missing.AOPs are recognized tools to destroy recalcitrant compounds or, at least, to transform them into biodegradable species. Diuron (a phenylurea herbicide) and atrazine (from the triazine chemical class) are the most studied pesticides from Directive 2013/39/EU. Fenton-based processes are the most frequently applied to treat priority compounds in water and their efficiency typically increases with the operating temperature as well as under UV or solar light. Heterogeneous photocatalysis is the second most used treatment to destroy pollutants defined in the Directive. Ozone alone promotes the partial oxidation of pollutants, and an increase in the effluent biodegradability, but complete mineralization of pollutants is difficult. To overcome this drawback, ozonation has been combined with heterogeneous catalysts, addition of H₂O₂, other AOPs (such as photocatalysis) or membrane technologies.     

Ecological and economic impacts of different irrigation and fertilization practices: case study of a watershed in the southern Iran

Best management practices, such as conservation tillage, the optimum level of irrigation, fertilization, are frequently used to reduce non-point source pollution from agricultural land and improve water quality. In this study, we used the soil and water assessment tool to model the impacts of different irrigation (adjusted to crop need), cropping and fertilization practices on total nitrogen loss. The economic impacts of these practices on crop net farm income were also evaluated. For this purpose, the model was calibrated through comparing model outputs with observations to ensure reliable hydrologic, crop yield and nitrate leaching simulations. The results showed that by reducing water or fertilizer or combination of both, we can reduce nitrate leaching. For wheat and corn, the best scenario was S1n1 (combination between reduction by 10 % of water and nitrogen fertilizer application, simultaneously) and S2n3 (combination of 20 and 30 % reduction in water and fertilizer application), respectively. These scenarios are both ecologically and economically desirable. Also, decreasing nitrogen fertilization by 50 % for corn would decrease the nitrate pollution from 101.1 to 32.3 kg N ha^?1; therefore, this strategy is ecologically desirable but economically unsound. So, there are opportunities for environmental decision makers to encourage farmers to implement these strategies. Also, since the nitrogen leaching cannot decrease without a reduction in net farm income for crops such as corn; hence, the losses of farmers should be compensated.     

多重人类活动干扰下赣江流域水环境和鱼类资源的研究现状分析

赣江是长江中下游的重要支流,赣江流域的水生态安全直接关系到长江经济带建设的可持续与绿色发展。然而,近些年来,人类活动干扰对赣江流域水生态的影响还在持续增加。该文综述了截止2017年12月赣江流域的水环境、鱼类资源及人类活动干扰影响的相关文献。目前,赣江流域水环境处于中度污染级别,有机污染物增加,无机污染物无显著变化。鱼类共有124种,隶属10目32科。经统计近10年的鱼类资源,赣江流域鱼类有7目35科120种,其中上游鱼类4目14科22种,中游鱼类6目28科82种,下游鱼类7目28科91种。全流域10年中未发现的鱼类包括中华鲟、鲥鱼、刀鲚、弓斑东方鲀、斑条鱊、短须鱊、拟尖头红鲌、似鱎、条纹小鲃、泉水鱼等33种。该文分析了影响赣江流域水生态的三类主要人类活动干扰:水电站建设,工农业污染和航运、采砂等,这些干扰增加了水体中营养盐和有机污染物的含量,同时破坏了水生生物生境,进而影响了鱼类的生存。随着赣江流域多个大型水电站的规划和建设,建议今后应进一步加强水电开发对水环境和鱼类资源的影响研究,同时开展生态修复,加强生境保护,严控涉水行为,完善生态补偿机制,以保证赣江流域的绿色发展。     

全氟辛烷磺酰基化合物水生生态风险和人体健康风险评价

全氟辛烷磺酰基化合物（Perfluorooctanesulfonate,PFOS ）广泛用于工农业生产,PFOS可通过不同的迁移路径迁移到大气、水和土壤等环境介质中。研究表明,PFOS是一种新的持久性有机物污染物,具有毒性,可通过食物链富集。2006年PFOS被欧盟议会和部长理事会列为限制销售和使用物质。本文引用中国沿海、亚洲海域和美国部分水域的PFOS暴露浓度数据,采用商值法对PFOS的水生生态环境风险进行了评价,建立了5 种因素水平的数学模型,并应用此数学模型对PFOS的人体健康风险进行了评价。结果表明我国部分地区和亚洲沿海PFOS的水生生态风险低于美国水域,亚洲沿海、我国部分地区以及美国部分城市水体中PFOS个人风险大小依次是我国部分地区<亚洲沿海<美国部分城市。     

The environmental impact assessment of wheat and barley production by using life cycle assessment (LCA) methodology

This study was conducted to assess the impact of cereals (wheat and barley) production on environment under rainfed and irrigated farming systems in northeast of Iran. Life cycle assessment (LCA) was used as a methodology to assess all environmental impacts of cereal grain production through accounting and appraising the resource consumption and emissions. The functional unit considered in this study was one ton grain yield production under different rates of nitrogen application. All associated impacts of different range of N fertilizer application were evaluated on the basis of the functional unit. In this study, three major impact categories considered were climate change, acidification, and eutrophication. In order to prepare final evaluation of all impacts on environment, the EcoX was determined. Results represented that, under low consumption of N fertilizer, the environmental impacts of both rainfed farming systems of wheat and barley was less than irrigated farming systems. Considering grain yield as response factor to different fertilizer application level, irrigated farming systems of wheat and barley with the range of 160–180 and?>220 (Kg?N?ha^?1) showed the maximum impact on environment. It seems LCA is an appropriate method to quantify the impact of utilized agricultural inputs and different managements on environment.     

水环境胁迫下的环鄱阳湖区城市化格局响应

当前城市化和水环境问题已成为全球共同面临的富有挑战性的问题，选取环鄱阳湖区作为研究样区，借助GIS技术，采用空间统计方法并建立水环境胁迫模型，对这种水环境胁迫下的城市化格局响应进行了研究。研究表明：（1）综合城市化计算显示，环湖区的城市化格局是随着与鄱阳湖体距离的增大，其城市化水平呈现出先增大后减小趋势，表明湖泊对城市化影响总体上显现出与距离相关的非线性分异格局；（2）空间统计结果显示，水资源富集的环湖核心区的空间关联比较显著，其水质对城市化水平的胁迫作用比较明显；（3）水胁迫度比较表明，在环湖边缘区和外围区水环境对城市化的胁迫强度级别有明显差异，随着与鄱阳湖体距离的增大，水环境对城市化的胁迫力也增大，表现出“中心 外围”逐渐增大的阶梯变化趋势     

水资源开发与生态环境协调发展的实例研究

结合水资源工程的必要性和以三峡工程为代表的水资源工程的环境保护措施，指出水资源开发与生态环境协调发展在理论和实践上的可行性。从防洪、能源安全、可持续发展以及水能资源蕴藏量等方面分析，我国总体水资源有限，而主要江河的中下游地区仍受到洪水威胁，在总体水资源利用程度上与世界平均水平相比还较低。水资源工程可以充分调节和利用水资源，以保障人类社会的可持续发展，但同时也会对河流形态、水文水动力学条件、水生态环境形成多方面的不利影响。为减缓或减免这些不利影响，必须从设计、施工、管理等各方面重视水资源开发与生态环境保护的协调发展。三峡工程是长江干流防洪和水资源利用的骨干工程，该工程从论证、施工及初期运行各个阶段，严格履行环境保护责任和义务，建立相关环境制度和标准，建立环境监测体系，设立科研项目和落实环境保护措施，保证了工程在发挥防洪、航运和发电功能的同时，努力成为环境友好型工程。     

武汉沉湖湿地水鸟群落特征及其与富营养化关系研究

富营养化是水中氮、磷等营养物质大量积累引起的水质污染现象,直接导致水体群落结构的改变,这一定程度上引起了以水生生物为食的水鸟的群落特征的变化。为找寻水鸟群落特征与富营养化两者的关系,2010年1月~2013年1月3年内按春夏秋冬4季对武汉沉湖湿地自然地保护区水鸟进行了调查,沉湖和张家大湖的水鸟多样性有明显的周年变化规律,多样性指数冬季最高,最高值分别为12.19和9.89;春夏季最低,最低值分别为7.53和2.45;对比分析了两个子湖,沉湖湖区与张家大湖湖区富营养化指数TLI分别为64和78,沉湖水鸟种类、数量和多样性指数皆高于张家大湖,湖泊富营养化会影响水鸟多样性。     

Using qualitative scenarios to understand regional environmental change in the Canadian North

This paper discusses the application of qualitative scenarios to understand community vulnerability and adaptation responses, based on a case study in the Slave River Delta region of the Northwest Territories, Canada. Three qualitative, graphic scenarios of possible alternative futures were developed, focusing on two main drivers: climate change and resource development. These were used as a focal point for discussions with a cross-section of residents from the community during focus groups, interviews and a community workshop. Significant overlap among the areas of perceived vulnerability is evident among scenarios, particularly in relation to traditional land use. However, each scenario also offers insights about specific challenges facing community members. Climate change was perceived to engender mostly negative livelihood impacts, whereas resource development was expected to trigger a mix of positive and negative impacts, both of which may be more dramatic than in the “climate change only” scenario. The scenarios were also used to identify adaptation options specific to individual drivers of change, as well as more universally applicable options. Identified adaptation options were generally aligned with five sectors—environment and natural resources, economy, community management and development, infrastructure and services, and information and training—which effectively offer a first step towards prioritization of “no regrets” measures. From an empirical perspective, while the scenarios highlighted the need for bottom-up measures, they also elucidated discussion about local agency in adaptation and enabled the examination of multi-dimensional impacts on different community sub-groups. An incongruity emerged between the suite of technically oriented adaptation options and more socially and behaviourally oriented barriers to implementation. Methodologically, the qualitative scenarios were flexible, socially inclusive and consistent with the Indigenous worldview; allowed the incorporation of different knowledge systems; addressed future community vulnerability and adaptation; and led to the identification of socially feasible and bottom-up adaptation outcomes. Despite some caveats regarding resource requirements for participatory scenario development, qualitative scenarios offer a versatile tool to address a range of vulnerability and adaptation issues in the context of other Indigenous communities.     

Occurrence,fate and ecological risk of five typical azole fungicides as therapeutic and personal care products in the environment: A review

Azole fungicides are widely used to treat fungal infection in human. After application, these chemicals may reach to the receiving environment via direct or indirect discharge of wastewaters, thus posing potential risks to non-target organisms. We aimed to review the occurrence, fate and toxicological effects of some representative household azole fungicides in the environment. Azole fungicides were widely detected in surface water and sediment of the aquatic environment due to their incomplete removal in wastewater treatment plants. These chemicals are found resistant to microbial degradation, but can undergo photolysis under UV irradiation. Due to different physiochemical properties, azole fungicides showed different environmental behaviors. The residues of azole fungicides could cause toxic effects on aquatic organisms such as algae and fish. The reported effects include regulation changes in expression of cytochrome P450-related genes and alteration in CYP450-regulated steroidogenesis causing endocrine disruption in fish. Further studies are essential to investigate the removal of azole fungicides by advanced treatment technologies, environmental fate such as natural photolysis, and toxic pathways in aquatic organisms.