Non-target Screening of Organic Contaminants in Sediments from the Industrial Coastal Area of Kavala City (NE Greece)

Lipophilic anthropogenic contaminants enter the environment from different kinds of human activities and corresponding emission sources. In the hydrosphere, they accumulate frequently in specific sedimentary zones, among others, and at coastal areas, forming reservoirs of pollutants. Marine and freshwater sediment samples as well as soil samples from a highly industrialized coastal area in Northern Greece have been analyzed in order to have a detailed view on the state of the particle-associated pollution. Noteworthy, based on extended GC/MS non-target screening analyses, interesting, so far unknown, or rarely documented contaminants have been identified and quantified comprising, e.g., mono- and dichlorocarbazoles, bromocarbazole, 2,6-di-tert-butyl-4-nitrophenol, etc. However, all relevant contaminants are discussed with respect to their spatial concentration profiles, their emission sources, and their pathway. In addition, numerous pollutants are suggested to become selected for environmental monitoring programs. Hence, this study can act as an example for adapting individual monitoring programs to the individual contamination in coastal areas.     

Assessment of the Salinization Process at the Coastal Area with Hydrogeochemical Tools and Geographical Information Systems (GIS): Selçuk Plain, Izmir, Turkey

The salinization process was investigated with hydrogeochemical tools to evaluate the origin of salinity in the Selçuk Plain. Na/Cl and Cl/Br molar ratios of coastal zone that covers an alluvial aquifer, karstic discharges, and a wetland are similar to the local seawater ratio. According to mixing ratios, seawater addition can reach 9–18% in both seasons at the coastal zone especially in karstic springs that are a kind of seawater–freshwater mixing points. A thematic map of the Salinization zone was constructed for the Selçuk Plain using geographical information system tools with different parameters such as major ion ratios, EC values, mixing ratios, and sodium adsorption ratio values. High correlation between Cl and Br, B, Li and Sr explains the salinization process that comes from marine intrusion. The δ ¹⁸O and δD composition of water samples varies between ?6.7‰ and ?2.9‰; ?37‰ and ?20‰, respectively. The coastal zone waters are plotted on the mixing line due to the effects of the salinization process in the plain.     

Sources of heavy metal pollution in the rhine basin

The concept of industrial metabolism is introduced as an analytical framework for many diffuse sources of pollution for which ‘end of pipe’ control will not work and pollution prevention at the source is required. the concept is applied to pollution in the Rhine Basin which ends up in the Netherlands Delta and the North Sea, where the character of the pollutants changes over time. Cadmium, lead and zinc pollution from point sources, traffic, corrosion and atmospheric deposition are considered. Calculations cover the period from 1950 to 2010. in this study strongly urbanized paved and unpaved areas are distinguished based on their transport of pollutants to surface waters.     

Assessing the environment-benthic fauna coupling in protected and urban areas of southern Brazil

Growing urbanization adjacent to aquatic systems may alter water, sediment and benthic community interactions. The ecological effects of urbanization on regional, local and site-specific spatial variations of benthic macrofauna and of sediment and water properties were investigated in relatively pristine rivers and in urban rivers of southern Brazil. The benthic communities were found to be different in urbanized and protected areas. Their predominant responses to environmental conditions were characterized as either a: (i) sensitive species assemblage, formed by polychaetes Nephtys fluviatilis and Heteromastus similis and the crustacean Kalliapseudes schubarti; or a (ii) tolerant species assemblage, formed by the polychaete Laeonereis acuta and by an unidentified oligochaeta Tubificidae. The relationships between fauna and environment differed between protected and urban rivers. In protected areas the fauna distribution was directly related to grain sorting and phaeophytin a in sediments; and to chlorophyll a, dissolved oxygen and phosphorus in water. In urban sites the strongest determinants of fauna distribution were the presence of lead, copper, dissolved phosphorus, chlorophyll a and phaeophytin a in sediments, and suspended particulate matter, dissolved phosphorus, nitrogen, and silicate in water. The comparison of animal-sediment-water interaction in natural and urban areas can be useful in planning environmental impact mitigation strategies for conservation even in rivers and estuaries with non-point sources of pollution.     

Ecotoxicological Evaluation in an Effluent and Petrochemical Waste Disposal Area

Water and sediment were studied to assess the impact of wastes from an area used for a disposal area of treated petrochemical effluents in Rio Grande do Sul, Brazil. The study was performed using the Daphnia magna (Straus 1820) for chronical evaluations, mutagenesis in Salmonella/microsome assays, and micronuclei induction in cultures of V79 cell to assess genotoxicity. Six sites were defined for chronic and genotoxic tests by micronuclei induction with liquid and sediment samples. Long-term tests were planned in semi-static flow, with microcrustaceans 2 to 26 h old in the beginning of assays. The minimum level of reproduction required to maintain the species was not reached. There are delays for the beginning of the reproductive process. Survival was also affected in some samples. The reproductive responses were more sensitive on identifying environmental quality than the survival rate. The study of mutagenicity by Salmonella/microsome assay made it possible to define the seasonality of the components showing greater frequency in winter. The predominant event was the frameshift mutation in assays with the presence of metabolism. However, the cytotoxic activity, although present in all seasons, was less frequent in winter. The genotoxicity analysis in V79 cells exposed to liquid samples from the area also showed that cytotoxicity was the most frequent event. This may have interfered in the detection of a potential micronuclei induction. The results showed that, even after treatment, effluents disposed on the soil continue with active pollutants interfering in cladoceran’s quality of life, cellular physiology, and DNA integrity.     

基于三维生态足迹扩展模型的中国海岸带生态足迹及其影响因素研究

[目的]计算中国大陆海岸带地区的生态足迹并分析其驱动因素,为生态文明建设与可持续发展提供参考。[方法]基于三维生态足迹扩展模型,计算中国大陆海岸带地区2008-2017年的生态足迹、生态承载力、足迹深度,从时间和空间两方面分析中国海岸带地区可持续发展的状况,并利用偏最小二乘法对驱动因素进行分析。[结果]①2008-2017年中国海岸带地区总生态承载力、人均生态足迹逐年增大,从组分贡献率来看,化石燃料用地人均生态足迹最大;②2008-2017年人均生态承载力变幅不大,在各省市中,广西壮族自治区人均生态承载力始终最大,上海市人均生态承载力始终最小;③足迹深度呈现出逐年增大趋势且深度值均大于1,消耗自然资本存量,生态赤字加剧。从空间上看,中北部省市的人均足迹深度普遍较大,南部的广西、广东、福建3省足迹深度则相对较低;④经济发展、城市规模、环境污染和区际交流是导致生态足迹和足迹深度增加的驱动因素;生态建设和科学技术提高对缓解生态足迹和足迹深度加大有着积极作用。[结论]未来可以通过调整产业结构和人口结构,改变消费方式,进一步加强生态建设和提高科技水平来实现中国海岸带地区的可持续发展。     

Influences on the Distribution of Marine Debris on the Seafloor of Shallow Coastal Areas in Greece (Eastern Mediterranean)

The abundance and composition of marine benthic debris was investigated in shallow coastal areas of Greece (eastern Mediterranean). The mean total density of marine debris in the areas surveyed was 15 items per 1000 m² and ranged from 0 to 251 items per 1000 m², with plastics dominating. Much higher marine debris densities were found in this study than those found in most studies surveying the continental shelf or the deep seafloor, indicating that pollution with marine debris is more intense in coastal areas. Greater abundance of marine debris was found in bays than in open areas. Artisanal fishing activities were found to significantly contribute to marine pollution with debris. In the Saronicos Gulf, a densely populated and highly industrialized area, the abundance of marine debris was higher than the rest of the Greek areas surveyed.     

Source and Fate of Heavy Metals in Marine Sediments from a Semi-Enclosed Deep Embayment Subjected to Severe Anthropogenic Activities

Urban and industrial activities are major sources of pollution to marine environments. Sediments can act as sink and reservoir for a wide range of contaminants, including heavy metals. Environmental quality assessment in this compartment can provide useful information to control pollution in coastal areas. Lately, implementation of Environmental Legislative Frameworks within the European Community is increasing awareness about the importance of marine sediment quality in order to achieve a ??Good Environmental Status.?? In this work, the study of superficial marine sediments allowed assessment of source and fate of heavy metals in a semi-enclosed deep embayment that is subjected to severe anthropogenic activities. Results indicated that accumulation of heavy metals takes place mainly in proximity to anthropogenic sources (industrial area and harbors), but pollution can also spread to greater depths affecting the whole ecosystem. Multivariate statistics helped identify source and fate of several elements, showing evidence of pollutants transfer from urban wastewaters, industrial effluents, and atmospheric emissions to marine sediments. Results provided useful information for the implementation and development of Environmental Management Strategies under European Legislative Frameworks.     

Water Quality Characterization in the Northern Florida Everglades

The Loxahatchee National Wildlife Refuge (Refuge) developed as a system with waters low in nutrients. Today, the Refuge wetlands are impacted by inflows containing elevated nutrient concentrations originating from agricultural sources flowing into canals surrounding the west side and from urban and horticultural areas flowing into canals surrounding the eastern side of the Refuge. We analyzed water quality sampled at 40 sites divided into eastern and western areas and four zones in the Refuge. We defined four zones as the canals surrounding the Refuge marsh, the perimeter zone, the transition zone, and the interior zone. The canal receiving agricultural inflows had greater alkalinity and conductivity (SpC), Si and SO₄ but lower turbidity and total suspended solids than the canal receiving urban and horticultural inflows. Alkalinity, total dissolved solids (TDS), SpC, Ca, Cl, and SO₄ concentrations were greater in the perimeter than in transition and interior zones. Alkalinity and SpC values and SO₄ concentrations were greater in the transition than in interior zone. Alkalinity, SpC, and TDS values and Ca, SO₄, and Cl concentrations correlated in negative curvilinear relationships with distance from the canal (r ²?=?0.78, 0.70, 0.61, 0.78, 0.64, 0.57, respectively). Analysis of multiple water quality parameters may reveal the complexity of interactions that might be overlooked in a simple single parameter analysis. These data show an impact of canal water containing high nutrient concentrations on water quality flowing from the canal towards the Refuge interior.     

Impact of forest drainage on the macroinvertebrates of a small boreal headwater stream: Do buffer zones protect lotic biodiversity?

Forest drainage, utilizing protective buffer zones, caused clear changes in the habitat structure as well as in the species richness and composition of moss-dwelling invertebrates in a small headwater stream. The aquatic moss Fontinalis dalecarlica was the dominant habitat in the control riffle areas, whereas sand dominated the riffles impacted by forest ditches. The significance of the forest ditches as a source of inorganic material was studied by comparing the quality of both indigenous and transplanted moss habitats. The Fontinalis tufts in the affected sites were silted up and contained a significantly higher average amount of inorganic matter than the mosses in the control site. The species richness of invertebrates within the silted mosses was significantly lower than at the control site. Shredder-feeding stoneflies dominated the moss communities of the control site, whereas Simuliidae dominated the impacted riffles. We suggest that the drainage-induced impoverishment of the benthic communities is due to two combined disturbance factors: (1) deposition of the particles on benthic habitats and (2) particle movement along the surfaces. Further, it is concluded that the present buffer zones and sedimentation ponds are insufficient to protect the biodiversity of streams draining easily eroding lands. In order to protect these vulnerable lotic ecosystems effectively, the most erodible parts of the catchment area should be undrained, and more retentive buffer mechanisms should be utilized in the drainage areas.     

Genotoxicity in German Surface Waters - Results of a Collaborative Study

As surface waters are widely used for the preparation of drinking water, appropriate test systems are required for the monitoring of possible genotoxic contaminations. In the course of a BMBF-funded collaborative project several methods (Ames test, umu test, alkaline elution, DNA unwinding assay, Comet assay and unscheduled DNA-synthesis test) have been examined for their ability to measure genotoxicity particularly in natural surface waters. The project was subdivided into two parts: In the first part appropriate test versions were developed (sensitized Ames test, luminometric umu test, alkaline elution using clams, Comet assay with fish cells or aquatic plants), adapted to the test subject and validated regarding their sensitivity towards standard genotoxins. All test results were statistically evaluated. In the course of the second part both natural and concentrated samples of the rivers Rhine, Elbe, Mulde, Wupper and one drinking water resource (Wahnbachbarrage) were tested. In parallel all samples were chemically analyzed. Among the unconcentrated samples several statistically positive test results were obtained both for the rivers Elbe and Rhine especially with the Ames test and the Comet assay. Only one river (Wupper) showed significant genotoxicity in the umu test. In this case chemical analysis revealed concentrations of about 41 and 47 µg/l of fluoroquinolonic acid, a bacterial gyrase inhibitor which may be responsible for this effect. No genotoxicity could be found in the drinking water resource even after concentration. The water extracts clearly showed different background genotoxicity in the umu test corresponding to increased pollution along the Rhine (Karlsruhe < K ln < D sseldorf). The eucaryotic in vitro tests revealed comparable results with nonconcentrated water samples. As a conclusion of the study we propose a graduated testing battery consisting of a bacterial (umu or Ames test) and an eucaryotic test like the Comet assay or the alkaline elution assay followed by an additional eucaryotic test (UDS test or micronucleus test) in a decisive function. There is a need for further evaluation by effect-orientated chemical analysis which should be done in the case of positive genotoxicity results in at least two tests or persistent positive results in only one.     

长江三角洲地区地表水污染的模式与对策

On the basis of field investigations, observations and experimental data combined with environmental monitoring information, the status and the spatial and temporal patterns of surface water pollution over thepast ten years in the Yangtze River Delta have been assessed. The water quality of large rivers is still verygood but most of the medium-sized and small rivers have been very seriously polluted. The appearance of black and odorous conditions in rivers in the urban areas has increased due to serious pollution by organic matter with consequent high oxygen demand. Annual increases in N and P concentrations in lakes haveaccelerated eutrophication. The water quality of rivers in small towns is rapidly deteriorating. The mainsources of surface water pollution include industrial and domestic sewage, animal manures, chemical fertilizersin farmland, and polluted sediments in rivers and lakes.Counter measures against these sources of pollution are presented. Regional laws and regulations for protection of surface waters and their enforcement are urgently required. A regional water environmental management agency should be established. The construction of sewage treatment plants of varying capacity must be accelerated to increase the proportion of sewage treated and to improve the quality of treated effluent. Animal wastes must be recycled effectively and efficiently, and the application rates of fertilizers and manures must be balanced with crop nutrient requirements to prevent diffuse pollution from agriculture. The comprehensive rehabilitation of medium-sized and small rivers should be intensified, and the delimitation and protection of the areas used as sources of drinking water should be strengthened.     

Relationship Between Fecal Indicators in Sediment and Recreational Waters in a Danish Estuary

The European Union has introduced a new bathing water directive where future classification of recreational waters will be based on the microbial parameters Escherichia coli, and intestinal enterococci. Introduction of enterococci as a new quality parameter may pose a challenge in some areas because relatively less is known about these organisms compared to E. coli. In the present study, the relative abundance of intestinal enterococci, E. coli, and ten fecal sterol and stanol biomarkers were investigated in water and sediment at two estuarine beach sites affected by fecal pollution. In the bathing water, enterococci were relatively more abundant at low E. coli concentrations. In the sediment, enterococci were generally more abundant than E. coli with surface concentrations between 1.0?×?10² and 4.5?×?10³ CFU cm^?3. Enterococci populations were relatively similar in water and sediment, and were phenotypically different from that of nearby pollution sources. The putative human specific genetic marker esp in Enterococcus faecium was not detected in water or sediment samples despite occasional inputs of human waste from storm water overflows. Sterol and stanol profiles suggested a direct link between water and sediment pollution profiles on days with wind conditions that facilitated resuspension. Sediment resuspension may occur at wind speeds exceeding 6–8 m s^?1, and could contribute significantly to enterococci concentrations in the overlying water. The study emphasized that recontamination of the water column due to wind induced resuspension should be considered when evaluating indicator levels and microbial hazards in estuarine recreational waters.     

重庆市畜禽粪污的区域分布及其水环境响应特征分析

为解决常见畜禽养殖排污量估算方法存在的缺陷和核实重庆市畜禽养殖目前污染状况,在调研当地畜禽养殖业及其排放状况的基础上,提出计算规模化养殖场排污量的校正方法,核算在现有治污模式下的典型畜禽排污量;以重庆市五大功能区为研究对象,基于不同水环境功能区划,采用等标污染负荷比法,研究了化学需氧量(CODCr)、总氮(TN)、总磷(TP)等标排放量的功能区分布及其潜在水环境响应特征,进而确定了畜禽养殖业主要污染区域和主要污染物,为重庆市不同功能区的产业发展和环境保护提供决策依据。结果表明,重庆市2013年畜禽养殖量为411.81万猪当量,粪便、尿、CODCr、TN、TP实物排放量分别为2.27×106 t、1.66×106 t、3.03×104 t、0.72×104 t和1.87×104 t。CODCr、TN、TP等标排放量分别为1.44×109 m3、7.94×109 m3和1.02×1011 m3。主要污染区域为城市发展新区和渝东北生态涵养发展区,主要污染物为TP,且重庆市畜禽养殖业的发展与功能区划有着显著相关关系。因畜禽养殖污染引起的全市水环境水质综合指数在0.22~4.12。城市发展新区和渝东北生态涵养发展区的水质超过标准,其余功能区均未超标。     

The use of clams as bioindicator of fecal pollution in seawater

The coastal waters of Kuwait are widely used for bathing during the long summer season. In order to assess the water quality along the beaches, a new approach was developed. It involves the use of clam, Circenita callipyga, as a bioindicator for seawater pollution by fecal coliform bacteria (FC), antibotic resistant fecal coliform (ABR-FC) and Salmonella spp. These organisms were detected in clam and water samples and the efficiency of clam in concentrating Salmonella was confirmed. The number of FC and ABR-FC in clam and water samples were compared and a higher number was detected in clams than in water. Five isolates of Salmonella from clams were also multidrug resistant. The data suggests that clam can be used as a bioindicator of seawater pollution and is preferable to direct testing of water. The resistance to antibiotics in E. coli isolated from water and clams collected at the same time and site was of similar pattern and was determined by R-plasmid.     

红枫湖流域非点源污染控制区划

非点源污染发生的广域性、分散性、随机性等特征使得对其进行效管控难度较大。以非点源污染关键源区识别为基础,对流域进行分区管控是实现非点源污染控制的有效途径。基于源头削减和过程管控协同管理的思路,将GIS技术、ArcSWAT模型、非参数检验和因子分析技术相结合,以农耕养殖程度较高的贵州红枫湖上游羊昌河流域为研究区,通过对流域近5 a非点源污染负荷特征进行模拟,识别影响非点源污染流失的关键因素,在此基础进行污染控制区划。结果表明：1）总氮和总磷负荷高风险区主要集中于地势较高且农业耕作活动频繁区域,刘官乡、黄腊乡、旧州镇及白云镇是非点源污染控制的重点乡镇;2）采用多因素方差分析7种不同因素对流域非点源污染负荷的影响程度表明,施肥量是影响总氮、总磷输出的最主要的因子,坡长、坡度及土地利用方式是次重要因子。针对羊昌河流域长期传统耕作以及化肥过量施用的现实特征来看,土壤有机磷的含量也会对总磷的输出产生一定的影响;3）羊昌河流域可划分为3个污染控制区,第1类：生态农业综合整治区（以近河道耕种区为主,面积254.4 km2）;第2类：污染治理区（农村生活及畜禽养殖区为主,面积405.74 km2）;第3类：生态修复区（高坡度强降雨区为主,面积464.47 km2）。研究结果可有效提升羊昌河流域非点源污染治理的效率,为水源地环境保护提供参考。     

高速发展的东南沿海地区资源与环境质量变化与可持续发展调整战略

Problems in water-land resources and environmental quality increase with the fast economic development in the coastal region of southeastern China,This region has the highest density in population,industry and towns in China,and the large export-oriented economy makes itself a strategic importance while China enters into international markets.The problems facing to this region include arable land reduction,land degradation aggravation,high percentage of built-up land with high rate of expansion,expanded non-point pollution,deteriorated water quality,decreasing biodiversity,destroyed ecosystems,sever air pollution,frequently occurred acid rain,and multi-pollutants.The important reaarch fields in the near future should include a )influence of high-intensity exploitaion of resources on changes of environment quality and its feedback;b) influence processes ,key mechanisms and adjustment principles for degradation of water,land-,and air-resources and environmental quality;c)evolvement processes and nurturing theory of bioiversity and ecological resourcs;and d) spatio-temporal variaiton and human-induced effects on regional resources and environment quality .Strategies for sustainable development in the region are as follows:a) controlling to ensure basic cultivated land area;b) enforcing remediation of polluted water environment,and controlling non-point pollution;c) strengthening ecological construciton and ecological security;and d) controlling multi-pollution and preventing trace toxic pollutants.     

PM10-bound Polycyclic Aromatic Hydrocarbons (PAHs) and Cancer Risk Estimation in the Atmosphere Surrounding an Industrial Area of Shanghai, China

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants in the urban atmosphere. In particular, atmospheric pollution has increasingly become severe in China due to its rapid urbanization and industrialization. In recent years, a few studies have presented information about POPs (such as PAHs, PCBs, OCPs) in aerosols at a molecular level in a limited number of cities such as Beijing, Qingdao and Guangzhou, as well as Hong Kong. Whereas, these cities are located in northern and southern China, respectively, where characteristics of atmospheric pollution might be different from those in the eastern cities, such as Shanghai. Atmospheric particle pollution is a persistent problem in Shanghai, a typical metropolis of China, which has several huge industrial regions. In order to gain a comprehensive understanding of the present state, properties and sources of PAHs pollution in Shanghai, PM₁₀ samples were collected at Coal-Fired Power Plant (CFP), Chlor-Alkali Chemical factory (CAC) and Coking and Chemical factory (CCF) in an industrial area, during the period, November 2004–September 2005. The concentrations of 16 PAHs were analyzed using the HPLC with UV visible detector. The results showed that the mean value of total PAHs in the industrial area was 64.85 ng m^?3; 3-ring PAHs were found at low levels, while 4-, 5- and 6-ring PAHs were found at high levels. The levels of BaP were 3.07 and 7.16 ng m^?3 at Chlor-Alkali Chemistry Factory and Coking and Chemistry Factory sites, respectively. PAHs levels exhibited distinct seasonal variation, with the highest level in autumn and the lowest in summer. The major source of PAHs at the industrial area was fossil fuel combustion, coal-burning, industrial furnaces including others. There was a very significant correlation of PAHs levels between CCF and CAC (R ²?=?0.91). The average concentration of BaP in the industrial area during the sampling period was 5.95 ng m^?3. It could be concluded the local population appears to be exposed to significantly high cancer risk (exceeding 2 ng m^?3 in autumn and winter) as compared to the population of other areas.     

辽宁省污灌区土壤重金属污染特征与生态风险评价

针对当前污灌区土壤污染研究中存在的问题,提出了一种模糊识别模型评价土壤综合环境质量,并对潜在生态风险指数法进行改进,用以计量重金属潜在生态风险。采用建立的方法对辽宁省污灌区土壤环境质量和重金属潜在生态风险进行了评价,结果显示:Cd是辽宁省污灌区首要重金属污染物,而Hg、Pb、Ni污染较为普遍;重金属的来源主要是灌溉污水和农田施肥;以工业废水为灌溉用水的灌区污染情况比以河水为灌溉用水的灌区污染严重;污灌区重金属元素污染程度大小依次为:Cd>Pb>Ni>Hg>Cu>Cr>As,而重金属潜在生态风险从大到小则依次为:Cd>Hg>Pb>Cu>Ni>As>Cr。总体来看,辽宁省污灌区存在一定程度的重金属污染,且具有较为明显的复合型污染特点,其潜在生态风险超出警戒水平,各灌区应根据各自污染特点和风险等级制定相应的污染防治对策。     

Impact of acid precipitation on freshwater ecosystems in Norway

Extensive studies of precipitation chemistry during the last 20 yr have clearly shown that highly polluted precipitation falls over large areas of Scandinavia, and that this pollution is increasing in severity and geographical extent. Precipitation in southern Norway, Sweden, and Finland contains large amounts of H⁺, SO⁼ ₄, and NO^? ₃ ions, along with heavy metals such as Cu, Zn, Cd, and Pb, that originate as air pollutants in the highly industrialized areas of Great Britain and central Europe and are transported over long distances to Scandinavia, where they are deposited in precipitation and dry-fallout. In Norway the acidification of fresh waters and accompanying decline and disappearance of fish populations were first reported in the 1920s, and since then in Sørlandet (southernmost Norway) the salmon have been eliminated from several rivers and hundreds of lakes have lost their fisheries. Justifiably, acid precipitation has become Norway's number-one environmental problem, and in 1972 the government launched a major research project entitled ‘Acid precipitation — effects on forest and fish’, (the SNSF-project). Studies of freshwater ecosystems conducted by the SNSF-project include intensive research at 10 gauged watersheds and lake basins in critical acid-areas of southern Norway, extensive surveys of the geographical extent and severity of the problem over all of Norway, and field and laboratory experiments on the effect of acid waters on the growth and physiology of a variety of organisms. Large areas of western, southern, and eastern Norway have been adversely affected by acid precipitation. The pH of many lakes is below 5.0, and sulfate, rather than bicarbonate, is the major anion. Lakes in these areas are particularly vulnerable to acid precipitation because their watersheds are underlain by highly resistant bedrock with low Ca and Mg contents. Apart from the well-documented decline in fish populations, relatively little is known about the effects of acid precipitation on the biology of these aquatic ecosystems. Biological surveys indicate that low pH-values inhibit the decomposition of allochthonous organic matter, decrease the species number of phyto-and zooplankton and benthic invertebrates, and promote the growth of benthic mosses. Acid precipitation is affecting larger and larger areas of Norway. The source of the pollutants is industrial Europe, and the prognosis is a continued increase in fossil-fuel consumption. The short-term effects of the increasing acidity of freshwater ecosystems involve interference at every trophic level. The long-term impact may be quite drastic indeed.