Suchergebnisse

AbstractNumerous anthropogenic factors, historical and contemporary, have contributed to declines in the abundance and diversity of freshwater fishes in North America. When Europeans first set foot on this continent some five hundred years ago, the environment was ineradicably changed. Settlers brought with them diseases, animals, and plants via the Columbian Exchange, from the old world to the new, facilitating a process of biological globalization. Invasive species were thus introduced into the Americas, displacing native inhabitants. Timber was felled for ship building and provisioning for agriculture, resulting in a mass land conversion for the purposes of crop cultivation. As European colonization expanded, landscapes were further modified to mitigate against floods and droughts via the building of dams and levees. Resources have been exploited, and native populations have been overfished to the point of collapse. The resultant population explosion has also resulted in wide-spread pollution of aquatic resources, particularly following the industrial and agricultural revolutions. Collectively, these activities have influenced the climate and the climate, in turn, has exacerbated the effects of these activities. Thus, the anthropogenic fingerprints are undeniable, but relatively speaking, which of these transformative factors has contributed most significantly to the decline of freshwater fishes in North America? This manuscript attempts to address this question by comparing and contrasting the preeminent drivers contributing to freshwater fish declines in this region in order to provide context and perspective. Ultimately, an evaluation of the available data makes clear that habitat loss, obstruction of streams and rivers, invasive species, overexploitation, and eutrophication are the most important drivers contributing to freshwater fish declines in North America. However, pesticides remain a dominant causal narrative in the popular media, despite technological advancements in pesticide development and regulation. Transitioning from organochlorines to organophosphates/carbamates, to pyrethroids and ultimately to the neonicotinoids, toxicity and bioaccumulation potential of pesticides have all steadily decreased over time. Concomitantly, regulatory frameworks designed to assess corresponding pesticide risks in Canada and the USA have become increasingly more stringent and intensive. Yet, comparatively, habitat loss continues unabated as agricultural land is ceded to the frontier of urban development, globalized commerce continues to introduce invasive species into North America, permanent barriers in the form of dams and levees remain intact, fish are still being extracted from native habitats (commercially and otherwise), and the climate continues to change. How then should we make sense of all these contributing factors? Here, we attempt to address this issue.

The study reinforces the belief of geo-politicians that competition over and control of, vital resources –- be they oil, strategic materials for warfare, water and sea lanes or minerals – is the main cause of conflict between states and adds substance to that belief by attributing equal significance to the territorial control of freshwater resources as an issue of high-politics in international relations. To highlight theoretical and policy relevance it formulates a theoretical model befittingly explaining linkages between war and peace over vital water resources and explains when the rival riparian compromise on vital concerns and put political issues on the backburner. With this backdrop the Dissertation addresses the question: Is water a cause of conflict or catalyst for peace and establishes linkage between the Indus water resource and the Kashmir dispute. While highlighting role of Indus waters in political thinking, strategic planning and warfare between India and Pakistan the study projects its future implications for war and peace in the region and highlights emerging scenarios in the wake of growing water scarcity and environmental degradation. The study also suggests practicable policy recommendations for sustainable development and durable peace in the region.

Onondaga Lake in Syracuse, New York is a model for the analysis and management of a polluted urban lake. Sometimes referred to as "the most polluted lake in the United States", Onondaga Lake is one of only two lakes for which a federal advisory body has been set up to guide environmental remediation. The recipient of significant municipal effluent and industrial waste for more than a century, Onondaga Lake has been the focus of intensive limnological investigation and extensive remediation efforts. This book is a comprehensive presentation of the scientific knowledge about Onondaga Lake, based on research coordinated by the Upstate Freshwater Institute. Onondaga Lake: Limnology and Environmental Management of a Polluted Urban Lake is the most complete case study of a lake, and will be of interest to water quality scientists, engineers and managers, as well as environmental engineers, modelers, and policymakers

Climate change -- Concentrated animal feeding operations -- Emissions trading -- Endangered species -- Environmental justice -- Freshwater use and pollution -- Fuel and energy efficiency standards -- Genetically modified foods -- Grazing -- Hazardous waste disposal -- Hydraulic fracturing ("fracking") -- Hydoelectric energy -- Indoor air pollution -- Logging on public lands -- Marine pollution and protection -- Mining -- Motorized recreation on public lands -- National parks -- Noise pollution -- Nuclear waste disposal -- Oil and natural gas drilling -- Outdoor air pollution -- Ozone depletion -- Pesticides -- Public lands -- Solar energy -- Sustainability -- Transportation -- Wetlands -- Wilderness conservation -- Wind energy.

Abstract
Freshwater is one of the most essential needs of society. Due to the limited amount of potable water on Earth, guaranteeing the supply of clean water to society is a major challenge. By utilizing abundant sunshine, solar still could be utilized to provide the necessary amount of drinking water in remote locations. The issue of restricted daily production inspires researchers to investigate novel ways for enhancing the thermal performance of desalination techniques while lowering expenses. In this work, the scholars improved a unique distillation method related to solar stills. The authors presented a novel improvement to the vertical distiller design to enhance the exposure area while decreasing the thickness of the water layer as much as possible. Thus, two rotational discs (flat type) covered with wick were integrated into the vertical distiller basin at 1.5 rpm and 5 cm water depth. Furthermore, providing vacuum via a fan with an external condenser. Besides, various rotating speeds (from 400 to 2000 rpm) were tested to determine the perfect fan speed that provides the maximum yield. The experimental findings revealed that the modified vertical distiller produced more pure water than the conventional distiller. Moreover, the rotation of wick discs and vacuum fan enhanced the yield of distillers enormously. Besides, the highest distiller performance was obtained at 1.5 rpm (wick disc speed) and 1600 rpm (fan speed, 10 min ON, and 10 min OFF). Moreover, the daily freshwater output was 19.1 L/m2 day for MDSVD without the fan and 23.65 L/m2 day for MDSVD with the fan. So, the yield of MSSVD without/with vacuum fan was improved by 548.65% and 660.45%, respectively, over that of CTD. The best thermal efficacy for MDSVD without/with vacuum fan was 77.47% and 84.05%, respectively. Lastly, the average cost of freshwater was 0.021, 0.0177, and 0.0164 $/L for CTD, MDSVD without/with vacuum fan, respectively.

AbstractWe assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section "other invertebrates" review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.

Freshwater resources of small islands as Breton islands are naturally restricted by hydroclimatic and hydromorphological conditions. The hypothesis that lack of freshwater could limit their economic development, namely touristic development, has often been mentioned in the bibliography. Results of investigations in archives and interviews of "local memories" underline how much water management constituted a main topic in Breton island history. That is testified by many references to the question, namely relative to conflicts of uses. Nowadays, freshwater question seems to be secondary to managers and islanders. For the last four decades, hydraulic equipments had actually been considerably improved in order to supply the increasing water demand due to tourism activity and the improvement of living standards. Technico-economic analysis shows that such a structural effort has led to hydraulic oversizing and a relative overinvestment in comparison with regional and national figures. Nevertheless summer water shortage risk is not stemed yet for some islands that still remain vulnerable to the most important droughts, as in 2005 when Belle-Île faced its fourth water shortage since the 1950's. While integrating natural, human and infrastructural parameters, the proposed retrospective and prospective assesment of water shortage risk constitutes a new approach to analyse the sustainability of water policy on small islands, giving managers figures to make decisions. ; Les contextes hydroclimatiques et hydromorphologiques qui caractérisent les petites îles, à l'instar des îles bretonnes, sont autant de contraintes naturelles qui limitent physiquement leurs ressources endogènes en eau. La bibliographie a souvent émis l'hypothèse selon laquelle l'eau pourrait justement constituer un frein à leur développement, surtout touristique. Dans les cas bretons, les recherches en archives et les témoignages des « mémoires locales » rappellent combien l'eau fut une préoccupation insulaire majeure : c'est toute leur histoire moderne qui est racontée dans les conflits d'usages de l'eau aux XVIIIème et XIXème siècles et dans la première moitié du XXème. Certes, les politiques d'équipements hydrauliques des quarante dernières années ont globalement répondu, avec efficacité, à la très forte croissance des besoins hydriques, modifiant de fait les politiques locales de gestion de l'eau. Celle-ci n'est plus – a priori – une préoccupation majeure ni des gestionnaires ni des insulaires. L'analyse technico-économique montre que l'effort structurel réalisé a induit un surdimensionnement relatif des infrastructures et d'importants surinvestissements comparés aux moyennes régionales et nationales. Pour autant, le risque de pénurie estivale n'est pas complètement jugulé et certaines îles restent vulnérables aux aléas climatiques : en témoigne la situation critique de Belle-Île pendant la sécheresse de 2005. En intégrant les composantes naturelles, anthropiques et infrastructurelles, l'estimation rétrospective et prospective du risque de pénurie constitue une approche nouvelle pour l'évaluation de la durabilité des politiques de gestion de la ressource en eau.

Freshwater resources of small islands as Breton islands are naturally restricted by hydroclimatic and hydromorphological conditions. The hypothesis that lack of freshwater could limit their economic development, namely touristic development, has often been mentioned in the bibliography. Results of investigations in archives and interviews of "local memories" underline how much water management constituted a main topic in Breton island history. That is testified by many references to the question, namely relative to conflicts of uses. Nowadays, freshwater question seems to be secondary to managers and islanders. For the last four decades, hydraulic equipments had actually been considerably improved in order to supply the increasing water demand due to tourism activity and the improvement of living standards. Technico-economic analysis shows that such a structural effort has led to hydraulic oversizing and a relative overinvestment in comparison with regional and national figures. Nevertheless summer water shortage risk is not stemed yet for some islands that still remain vulnerable to the most important droughts, as in 2005 when Belle-Île faced its fourth water shortage since the 1950's. While integrating natural, human and infrastructural parameters, the proposed retrospective and prospective assesment of water shortage risk constitutes a new approach to analyse the sustainability of water policy on small islands, giving managers figures to make decisions. ; Les contextes hydroclimatiques et hydromorphologiques qui caractérisent les petites îles, à l'instar des îles bretonnes, sont autant de contraintes naturelles qui limitent physiquement leurs ressources endogènes en eau. La bibliographie a souvent émis l'hypothèse selon laquelle l'eau pourrait justement constituer un frein à leur développement, surtout touristique. Dans les cas bretons, les recherches en archives et les témoignages des « mémoires locales » rappellent combien l'eau fut une préoccupation insulaire majeure : c'est toute leur histoire moderne qui est racontée dans les conflits d'usages de l'eau aux XVIIIème et XIXème siècles et dans la première moitié du XXème. Certes, les politiques d'équipements hydrauliques des quarante dernières années ont globalement répondu, avec efficacité, à la très forte croissance des besoins hydriques, modifiant de fait les politiques locales de gestion de l'eau. Celle-ci n'est plus – a priori – une préoccupation majeure ni des gestionnaires ni des insulaires. L'analyse technico-économique montre que l'effort structurel réalisé a induit un surdimensionnement relatif des infrastructures et d'importants surinvestissements comparés aux moyennes régionales et nationales. Pour autant, le risque de pénurie estivale n'est pas complètement jugulé et certaines îles restent vulnérables aux aléas climatiques : en témoigne la situation critique de Belle-Île pendant la sécheresse de 2005. En intégrant les composantes naturelles, anthropiques et infrastructurelles, l'estimation rétrospective et prospective du risque de pénurie constitue une approche nouvelle pour l'évaluation de la durabilité des politiques de gestion de la ressource en eau.

Freshwater resources of small islands as Breton islands are naturally restricted by hydroclimatic and hydromorphological conditions. The hypothesis that lack of freshwater could limit their economic development, namely touristic development, has often been mentioned in the bibliography. Results of investigations in archives and interviews of "local memories" underline how much water management constituted a main topic in Breton island history. That is testified by many references to the question, namely relative to conflicts of uses. Nowadays, freshwater question seems to be secondary to managers and islanders. For the last four decades, hydraulic equipments had actually been considerably improved in order to supply the increasing water demand due to tourism activity and the improvement of living standards. Technico-economic analysis shows that such a structural effort has led to hydraulic oversizing and a relative overinvestment in comparison with regional and national figures. Nevertheless summer water shortage risk is not stemed yet for some islands that still remain vulnerable to the most important droughts, as in 2005 when Belle-Île faced its fourth water shortage since the 1950's. While integrating natural, human and infrastructural parameters, the proposed retrospective and prospective assesment of water shortage risk constitutes a new approach to analyse the sustainability of water policy on small islands, giving managers figures to make decisions. ; Les contextes hydroclimatiques et hydromorphologiques qui caractérisent les petites îles, à l'instar des îles bretonnes, sont autant de contraintes naturelles qui limitent physiquement leurs ressources endogènes en eau. La bibliographie a souvent émis l'hypothèse selon laquelle l'eau pourrait justement constituer un frein à leur développement, surtout touristique. Dans les cas bretons, les recherches en archives et les témoignages des « mémoires locales » rappellent combien l'eau fut une préoccupation insulaire majeure : c'est toute leur histoire moderne qui est racontée dans les conflits d'usages de l'eau aux XVIIIème et XIXème siècles et dans la première moitié du XXème. Certes, les politiques d'équipements hydrauliques des quarante dernières années ont globalement répondu, avec efficacité, à la très forte croissance des besoins hydriques, modifiant de fait les politiques locales de gestion de l'eau. Celle-ci n'est plus – a priori – une préoccupation majeure ni des gestionnaires ni des insulaires. L'analyse technico-économique montre que l'effort structurel réalisé a induit un surdimensionnement relatif des infrastructures et d'importants surinvestissements comparés aux moyennes régionales et nationales. Pour autant, le risque de pénurie estivale n'est pas complètement jugulé et certaines îles restent vulnérables aux aléas climatiques : en témoigne la situation critique de Belle-Île pendant la sécheresse de 2005. En intégrant les composantes naturelles, anthropiques et infrastructurelles, l'estimation rétrospective et prospective du risque de pénurie constitue une approche nouvelle pour l'évaluation de la durabilité des politiques de gestion de la ressource en eau.

Fisheries provide food. In industrialized nations, the overwhelming portion of seafood comes from a small number of commercial fishers and increasingly aquaculture (1). Fisheries also contribute to leisure and recreation. In developed nations, 1 in 10 people fishes for pleasure, amounting to at least 220 million recreational fishers worldwide (2, 3)—more than 5 times the number of commercial capture fishers (1). This means that the vast majority of people fishing today do so recreationally (Fig. 1). ; This work was supported by the National Socio-Environmental Synthesis Center (SESYNC) under funding received from the National Science Foundation (Grant DBI-1052875), the European Union through the European Maritime and Fisheries Fund, and the State of Mecklenburg-Vorpommern (Germany) (Grant MV-I.18-LM-004, B 730117000069); the German Federal Ministry of Education and Research (Grants 01LC1826E and 033W046A), the Natural Sciences and Engineering Research Council of Canada, Genome British Columbia (BC), and the BC Freshwater Fisheries Society.

Chrysophycean algae are a diverse and often abundant group of primarily freshwater phytoplankton, characterized by the endogenous formation of siliceous cysts or stomatocysts (also called statospores or statocysts). Cyst morphology is highly variable, but believed to be species-specific. Recently, cysts have received considerable attention from phycologists and especially paleoecologists who wish to use these indicators for assessments of environmental change. Nonetheless, attempts at using cysts have often been hampered by taxonomic problems. This Atlas dispels some of the mystery surrounding stomatocysts, facilitating the accurate identification of individual cyst morphotypes, and encouraging other workers to begin using these important indicators. The terminology used to describe cysts is outlined in detail, followed by detailed descriptions of cyst morphotypes, following International Statospore Working Group (ISWG) guidelines, complemented by scanning electron and light micrographs, as well as line illustrations. Any available biogeographical and ecological information is also provided. These descriptions will further accelerate the continued effort to link cyst morphotypes to the algae that produce them. For paleoecologists who wish to include stomatocysts in their studies, researchers working with living chrysophycean algae, and those interested in the morphology and ultrastructure of cyst morphotypes

Aptasensors have a great potential for environmental monitoring, particularly for real-time on-site detection of aquatic toxins produced by marine and freshwater microorganisms (cyanobacteria, dinoflagellates, and diatoms), with several advantages over other biosensors that are worth considering. Freshwater monitoring is of vital importance for public health, in numerous human activities, and animal welfare, since these toxins may cause fatal intoxications. Similarly, in marine waters, very effective monitoring programs have been put in place in many countries to detect when toxins exceed established regulatory levels and accordingly enforce shellfish harvesting closures. Recent advances in the fields of aptamer selection, nanomaterials and communication technologies, offer a vast array of possibilities to develop new imaginative strategies to create improved, ultrasensitive, reliable and real-time devices, featuring unique characteristics to produce and amplify the signal. So far, not many strategies have been used to detect aquatic toxins, mostly limited to the optic and electrochemical sensors, the majority applied to detect microcystin-LR using a target-induced switching mode. The limits of detection of these aptasensors have been decreasing from the nM to the fM order of magnitude in the past 20 years. Aspects related to sensor components, performance, aptamers sequences, matrices analyzed and future perspectives, are considered and discussed. ; We also would like to thank to EMERTOX (grant 734748), funded by H2020-MSCA-RISE 2016, and the Project CY-SENSORS (grant no. 032359), co-financed by COMPETE 2020, Portugal 2020 and the European Union through the ERDF, and by FCT through national funds. ...

From ancient time fisheries has been a major source of food for humanity and provider of employment and economic benefits to those engaged in it. Namibia is an arid country and with limited freshwater fisheries, chiefly found in the northern part of the country (Kavango and Zambezi River in the Caprivi region).Although freshwater fisheries is limited in Namibia, it serves a vital societal role in terms of food security and source of income. This stydy attempts to describe the status of Kavango fisheries from local people's and ecological perspectives. The study further attempts to analyse historical development of fisheries in Kavango and relate it to questions of sustainable resource utilisation in terms of ecosystem dynamic, socio-economic processes, institutions and rules and regulations. This was done by looking at the rationale behind the use of different types of gear (traditional and modern), socio-economic characteristics of fishing population, people's perception about the carrying capacity of fish resource and most efficient way of managing the resource (i.e. traditional, government or both). The results of this study indicated that some fish species have declined, and there is a growing awareness among local people that modern gears are the cause. People in Kavango seemed to prefer traditional over modern gears. There seemed to be few formal employment opportunities in the area, and the sale of fish as source of income has increased and to continue to increase further in the future. Both traditional and government laws and regulation are poorly enforced. However, the local people preferred fishing to be traditionally regulated. As is often the case in rural communities in Africa, women have the main household responsibility for food security and they tend to fish more than men. Co-management (where functions, rights and responsibilities of resouce management are shared among stakeholders), provision of good storage and transportation of fish and diversification of agricultural production are among the recommendations made to relieve pressure on the resource. ; M-MNRSA

AbstractBackgroundThe trophic magnification factor (TMF) is a metric that describes the average trophic magnification of a chemical through a food web. TMFs may be used for the risk assessment of chemicals, although TMFs for single compounds can vary considerably between studies despite thorough guidance available in the literature to eliminate potential sources of error. The practical realization of a TMF investigation is quite complex and often only a few chemicals can be investigated due to low sample masses. This study evaluated whether a pragmatic approach involving the large-scale cryogenic sample preparation practices of the German Environmental Specimen Bank (ESB) is feasible. This approach could provide sufficient sample masses for a reduced set of samples allowing screenings for a broad spectrum of substances and by that enabling a systematic comparison of derived TMFs. Furthermore, it was assessed whether plausible TMFs can be derived with the 'Food web on ice' approach via a comparison with literature TMF values.ResultsThis investigation at Lake Templin near Potsdam is the first TMF study for a German freshwater ecosystem and aimed to derive TMFs that are appropriate for regulatory purposes. A set of 15 composite biota samples was obtained and analyzed for an extended set of benchmark chemicals such as persistent organic pollutants, mercury and perfluoroalkyl substances. TMFs were calculated for all substances that were present in > 80% of the biota samples. For example, in the case of polychlorinated biphenyls, TMFs from 1.7 to 2.5 were determined and comparisons to literature TMFs determined in other freshwater ecosystems showed similarities. We showed that 32 out of 35 compounds analyzed had TMFs significantly above 1. In the remaining three cases, the correlations were not statistically significant.ConclusionsThe derived food web samples allow for an on-demand analysis and are ready-to-use for additional investigations. Since substances with non-lipophilic accumulation properties were also included in the list of analyzed substances, we conclude that the 'Food web on ice' provides samples which could be used to characterize the trophic magnification potential of substances with unknown bioaccumulation properties in the future which in return could be compared directly to the benchmarking patterns provided here.

Abstract
Background
Chemical surveillance in surface waters is crucial to identify potential threats to the health of freshwater ecosystems. Usually, the concentrations of pollutants are highly variable over the course of the year and often result in non-normally distributed data sets. Therefore, the European Water Framework Directive recommends measuring, e.g. priority substances at least 12 times a year to achieve an acceptable accuracy level for the estimation of the true mean annual loads. However, in Europe priority substances are often measured much less frequently. In this context, the aim of the present study was to analyze how sample size, temporal variability and skewness of the data sets influence the accuracy of the mean annual load estimation and the assessment of annual average environmental quality standards. For this purpose, sample size simulations using weekly composite samples of benzo(a)pyrene, 4-tert-octylphenol, fluoranthene and di(2-ethylhexyl) phthalate, selected as representatives for priority substances, were carried out.

Results
The sample size simulations showed two general patterns: the accuracy of the mean annual load estimation increased with increasing sample size and skewness and temporal variability were more apparent in smaller sample sizes. In right-skewed data sets, small sample sizes led, on average, to a systematic underestimation of the true mean annual load whilst in a few cases these led to an overestimation. Although the study was carried out on priority substances, results can be transferable to other pollutants. Furthermore, in small sample sizes a considerable proportion of the simulated means failed to detect annual average environmental quality standard exceedances.

Conclusions
The results of the present study indicate that the usage of small sample sizes is likely to result in an underestimation of the true mean annual pollutant loads in chemical surveillance and scientific research, thus potentially jeopardizing the validity of results. Therefore, it is recommended to avoid the usage of small sample sizes for the determination of mean annual pollutant loads. Furthermore, priority substances should be sampled according to the European Water Framework Directive guidelines at least 12 times/year to improve the assessment of the threat posed by pollutants to freshwater ecosystems in Europe.