Thèses sur le sujet « Water quality statu »

Le aree costiere sono sottoposte a pressioni antropogeniche e ai cambiamenti climatici. Negli ultimi venti anni, il concetto di gestione integrata della zona costiera ben presente nelle diverse azioni politiche, manca degli strumenti a supporto degli sforzi di pianificazione e gestione, specialmente nelle aree di estuario dove gli effetti dei bacini fluviali sulle zone costiere sono poco evidenziati nella maggior parte delle implementazioni. Gli ambienti costieri costituiscono un ambiente dinamico influenzato da input continentali sia naturali che antropogenici e controllato da fattori idrodinamici e climatici. Alcune zone costiere sono, con la loro geografia e geomorfologia, un recettore in cui sono presenti corpi idrici carichi di minerali esogeni e / o di materia organica derivanti dall'attività antropica. Il tempo di permanenza di questi corpi idrici è legato all'intensità delle correnti marine che controlla la distribuzione e la diluizione delle sostanze disciolte che possono influenzare l'ecosistema. Al fine di valutare lo stato trofico delle acque marine costiere del Mediterraneo, la Direttiva Quadro sulle Acque (DQA) richiedeva il monitoraggio della concentrazione di Clorofilla-a (Simboura et al., 2005) e l'indice trofico TRIX proposto da Vollenweider et al. (1998), che tiene conto delle sostanze nutritive complessive, della clorofilla e dell'ossigeno disciolto nell'ambiente. I nostri risultati hanno fornito la classificazione dello stato di qualità ecologica (EQS) dei tre siti Sonactere, Cheliff e Sokhra rispettivamente come stato Scadente, in base alla concentrazione di clorofilla, e come Cattivo, secondo l'indice trofico (TRIX). Le acque costiere di Mostaganem nell'Algeria occidentale mostrano una situazione di grave eutrofizzazione. Tuttavia, per capire meglio lo stato dell'ecosistema, è essenziale esplorare l'intera area costiera di Mostaganem per un lungo periodo. Gli indici Chl-a e TRIX sono stati sviluppati per le regioni del Mediterraneo, ma dovrebbero essere adattati alle condizioni locali in modo che siano pertinenti e più affidabili e rappresentativi, dato l'aspetto eterogeneo delle zone costiere del Mediterraneo.
Coastal areas are under anthropogenic and climate change pressures. During the last twenty years, the concept of Integrated Coastal Zone Management, as provides the overall policy frames, but tools supporting the planning and management efforts are almost lacking, especially in the estuary areas where the effects of river basins on coastal zones are nearly absent in most implementations. Coastal environments constitute a dynamic environment influenced by both natural and anthropogenic continental inputs and controlled by hydrodynamic and climatic factors. Some coastal zones are, by their geography and geomorphology, a receptor where are trapped water bodies loaded with exogenous mineral and /or organic matter resulting from the anthropic activity. The residence time of these water bodies is related to the sea currents intensity which controls the distribution and dilution of dissolved substances that can unbalance the ecosystem. In order to assess the trophic status of coastal Mediterranean marine waters, the Water Framework Directive (WFD) required the monitoring of the Chlorophyll-a concentration (Simboura et al., 2005) and the trophic index TRIX proposed by Vollenweider et al. (1998), which takes into account the overall nutrients, chlorophyll-a, and dissolved oxygen in the environment. Our results highlighted the ranking of the ecological quality status (EQS) of the three sites Sonactere, Cheliff, and Sokhra as bad according to the Chlorophyll concentration and as Poor status according to trophic index (TRIX). The coastal waters of Mostaganem in western Algeria have proved to be in a situation of severe eutrophication. However, to better understand the state of the ecosystem, it is essential to explore the entire coastal area of Mostaganem over a long period. The Chl-a and TRIX index were developed for Mediterranean regions but it should be adapted to local conditions so that it is relevant and more reliable and representative, given the heterogeneous aspect of the Mediterranean coastal zones.

Four experiments were conducted to investigate the effect of short term magnesium supplementation through drinking water prior to harvest on pork quality of pigs. Two days of magnesium supplementation (experiment 1) appeared optimal to improved pork quality. Older, slower growing pigs produced higher pork quality than younger faster growing pigs; however, magnesium supplementation had no effect (experiment 2). The presence of the Halothane and to a greater extent the Rendement Napole mutation reduced the quality of pork (experiment 3). Furthermore, pigs with both mutations had poorer pork quality than pigs with one mutation. Magnesium supplementation reduced pork quality when supplemented to pigs with the Halothane mutation. Pork quality was not affected when dose of magnesium supplemented in the water was altered (experiment 4). Although plasma magnesium was increased by magnesium supplementation, muscle magnesium was not affected. Overall, magnesium supplementation through drinking water for 2 days prior to harvest does not appear to be a method to consistently improve pork quality.

The paradigm shift in water quality management of South African water resources was based on current international trends. This significant move was from a previous emphasis on source management to a focus on finding a balance between water resource protection and water use. The current approach requires that water quality and quantity should be maintained for sustainable functioning of both the natural aquatic environment and socioeconomic development. This approach has placed the assessment of water quality status as a key decision tool in water quality management. Various assessment tools have been utilized to quantify the quality of South African water resources. In this study we assessed the compatibility of some of the methodologies that have been used in the Department of Water Affairs to determine and report on the water quality status of the resource. During the assessment the context and manner in which these methodologies can be utilized in water quality management were also addressed The Compliance Evaluation and Fitness for use categorization methodologies are both used to describe the water quality threshold of potential concern when dealing with the resource. Compliance Evaluation methodology uses a pass or fail assessment, while the Fitness for use categorization methodology uses a scaled approach allowing for the assessment of gradual change in the system. The out puts of these two methodologies, the Resource Water Quality Objectives and Fitness for use categories/ classes have both been used in the department as benchmarks to describe the current water quality status The assessment of the two methodologies indicated that there are similarities in the approaches and the principles behind the two processes. The observation of the results, however, indicated differences in the manner of presentation of the results, the interpretation of the outcome and in how water quality management measures that needs to be implemented are linked. Both methodologies are easy to apply when conducting water quality status assessments. However, the two methodologies are not sufficient on their own when making decisions on water quality management. It was concluded that although the compliance evaluation methodology can play a pivotal role when setting end of pipe standards, the process needs to consider the gradual changes of water quality in the river system in order to enable instigation of different water quality management measures at appropriate levels. Further it was recommended that with some modification the two approaches can be applied to assess water quality to support adequate water quality management decisions at various levels.
Dissertation (MSc)--University of Pretoria, 2013.
gm2014
Animal and Wildlife Sciences
Unrestricted

Lake Cospuden is an open pit lake in the mining region of Middle Germany south of the city of Leipzig. The lake which will be used for recreation is filling with recovering groundwater, surface water, and groundwater pumped form the neighboring Zwenkau mine, and is projected to reach its final water level by 2000. The physical limnology of Lake Cospuden is changing during the filling period from an unstratified to a stratified lake with a hypolimnion that is approximately twice as large as the epilimnion. The water quality is typical for a mining lake with low pH and high metal concentration. Due to the filling with neutral surface water, recovery of the initially low pH lake water can be observed. The microbiological environment is attenuated by relatively high phosphorus and nitrogen concentrations, but low chlorophyll-a concentrations, which might be attributed to carbon limitation of photosynthesis due to the low pH. After a rev1ew of general lake models, two models COLQUAL and AQUAMODl, were chosen to simulated the eutrophication process. COLQUAL indicated phosphorus and light as the limiting factors. AQUAMODl, which was modified to incorporate carbon limited photosynthesis, indicated that the eutrophication process is governed by carbon limitation and a mechanism that keeps the soluble reactive phosphorus concentration low, despite of high total phosphorus concentrations. This mechanism was assumed to be related to binding of phosphorus by suspended matter (e.g. clays) which creates turbidity observed in the lake. This study has a preliminary character and identifies future research. Because of its mining history, Lake Cospuden is a unique system and will require alternative approaches in order to evaluate and predict the water quality. Some first steps were attempted in this study.

RESUMO A Ãgua constitui o recurso de maior importÃncia para o homem, no entanto parece nÃo existir nenhuma preocupaÃÃo do ser humano em preservÃ-la, uma vez que as atividades diÃrias estÃo prejudicando cada vez mais, a qualidade deste recurso. Este trabalho teve por objetivo analisar a estrutura da comunidade fitoplanctÃnica e a qualidade da Ãgua de ecossistemas aquÃticos do Estado do Cearà (Brasil). Foram realizadas coletas mensais nas estaÃÃes chuvosa e seca, entre 2004 e 2007, nos seguintes ecossistemas: estuÃrios dos rios CauÃpe, MundaÃ, Cearà e Malcozinhado; lagoas de Jijoca, PecÃm, Uruaà e Maraponga; bicas do Ipu e das AndrÃas e aÃudes Favelas, da Corte e Campus do Itaperi. Os resultados mostraram mudanÃa significativa na estrutura da comunidade fitoplanctÃnica, influenciada principalmente pelos nÃveis de precipitaÃÃes pluviomÃtricas. As Bacillariophyceae foram predominantes nos ecossistemas analisados, exceto nos aÃudes Favelas, da Corte e do Campus do Itaperi, que apresentaram elevados nÃveis de eutrofizaÃÃo, com dominÃncia de Cyanophyceae, Zygnematophyceae e Chlorophyceae, respectivamente. As espÃcies raras, a grande maioria, formaram um grupo totalmente isolado daquelas consideradas dominantes, abundantes e pouco abundantes, constituÃdas por um nÃmero reduzido de espÃcies, confirmando a grande influÃncia sazonal da regiÃo, sobre a comunidade fitoplanctÃnica. Os ecossistemas apresentaram grande variaÃÃo na diversidade, riqueza e equitabilidade das espÃcies, no entanto a diversidade foi maior durante a estaÃÃo chuvosa. Com base nos teores de O2 e CO2 dissolvidos, amÃnia total, nitrito, fosfato, bem como, nos Ãndices do estado trÃfico do fosfato e/ou da transparÃncia da Ãgua e na presenÃa de bioindicadores, os estuÃrios dos rios MundaÃ, CauÃpe e CearÃ, a lagoa da Maraponga e os aÃudes Favelas, da Corte e Campus do Itaperi foram classificados como ambientes eutrÃficos; o estuÃrio do Rio Malcozinhado e as lagoas do PecÃm e de Uruaà como mesotrÃficos; e a lagoa de Jijoca e as bicas do Ipu e das AndrÃas como oligotrÃficos. Foram registrados diversos bioindicadores de Ãguas eutrofizadas e/ou poluÃdas, destacando-se a presenÃa de Cyanophyceae potencialmente tÃxicas nos diversos ecossistemas, com blooms no estuÃrio do Rio Cearà e no aÃude Favelas, nÃo sendo registrada uma biomassa significativa nos outros ambientes, mesmo naqueles que apresentaram elevado estado trÃfico, como o aÃude do Campus do Itaperi, com ocorrÃncia de bloom de Chlorophyceae e, no aÃude da Corte, cujo bloom foi de Zygnematophyceae, mostrando que na anÃlise de sanidade dos ecossistemas aquÃticos, a anÃlise conjunta dos parÃmetros biolÃgicos e fÃsico-quÃmicos do ecossistema à de suma importÃncia para um parecer ambiental adequado.
Water is the most important resource for humans, though it s eems there is no concern of human beings in preserving it, because daily activities increasingly under mine the quality of this resource. This study aimed to analyze the phytoplankton community structure and water quality in aquatic ecosystems of Cearà State (Brazil). Monthly collections were made during the rainy and dry seasons between 2004 and 2007 in the following ecosystems: the CauÃpe, MundaÃ, Cearà and Malcozinhado river estuarie s; the Jijoca, PecÃm, Uruaà and Maraponga lakes; the Ipu and Andreas waterspouts and the Favelas, Corte and Campus do Itaperi dams. The results showed significant changes in phytoplankton community structure, mainly influenced by levels of rainfall. The Bacillariophyceae were predominant in the ecosystems studied, except in the Favelas, Corte and Campus do Itaperi dams, which showed high levels of eutrophication, with dominance of Cyanophyceae, Zygnematophyceae and Chlorophyceae, respectively. Rare species, the great majorit y, formed a group totally isolated from those considered dominant, abundant and little abundant, consisting of a small number of species, confirming the major seasonal influence of the region's on the phytoplankton community. Ecosystems showed great variation in diversity, richness and evenness of species, however, diversity was highest during the rainy season. The following environments were classified according to the concentration of dissolved O 2 and CO2, total ammonia, nitrite, phosphate, as well as on trophic status indices of phosphate and/or water transparency and on the presence of bioindicators: the MundaÃ, CauÃpe and Cearà river estuaries, Maraponga lake and the Favelas, Corte and Campus do Itaperi dams as eutrophic environments; the Malcozinhado river estuary and PecÃm and Uruaà lakes as mesotrophic environments; and Jijoca lake and the Ipu and AndrÃas waterspouts as oligotrophic environment. Several bioindicators of eutrophic and/or polluted waters were recorded, in partic ular the presence of potentially toxic cyanobacteria in various ecosystems, with blooms in the Cearà river estuary and Favelas dam, while significant biomass was not recorded in other environments, even those showing a high trophic status, such as the Campus do Itaperi dam, with a Chlorophyceae bloom, and the Corte dam, with a Zygnematophyceae bloom, showing that the joint analysis of biological and physicochemical parameters of the ecosystem is of paramount importance for an appropriate environmental assessment of the health of aquatic cosystems.

The Occoquan Reservoir is part of the largest indirect potable reuse systems in the United States. It in an important water supply source for the Northern Virginia area, as well as, an ecological and recreational area. Furthermore, the Occoquan Reservoir protects the water quality of the Chesapeake Bay because it acts as a trap for sediments and pollutants. Continuous water quality monitoring and evaluation is critical to preserve this important water resource. Reservoir water quality can be affected by the delivery of pollutants from point and nonpoint sources, potentially causing problems such as eutrophication, excess salinization, presence of compounds that affect human and aquatic health. Different management strategies have been implemented at the Occoquan Reservoir to nutrient loading into the reservoir and address eutrophication issues, including nitrate addition to hypolimnetic waters and installation of a hypolimnetic oxygenation system. The goal of this study is to assess how current management strategies implemented in the Occoquan Reservoir have affected the water quality from 1973 to 2019, with particular emphasis on the data since 2003. This analysis of the Occoquan Reservoir and its tributary watershed includes the evaluation of hydrometeorological data and morphometric characteristics; establishment of long-term trends for water quality constituents; and determination of the trophic state of the reservoir. Data from water samples from four different stations located at the Occoquan Reservoir and four stations located throughout the Occoquan tributary watershed were analyzed for nutrients, principal ions and metals, synthetic organic compounds (SOCs), and other water quality parameters. Long-term water quality trends were determined using Mann-Kendall test and relationship between constituents was evaluated using Principal Component Analysis (PCA). Trophic state of the reservoir was assessed using Carlson's Trophic State Index (TSI), Vollenweider Model, and Rast, Jones, and Lee's Model. Results indicate the Occoquan Reservoir is a eutrophic waterbody. However, the nitrate management strategy and the installation of the hypolimnetic system have improved reservoir water quality, reducing concentrations of nutrients and metals.
Master of Science
The Occoquan Reservoir is part of the largest indirect potable reuse systems in the United States. Indirect potable reuse refers to the planned discharge of reclaimed water into a water supply source, such as a reservoir or lake. The Occoquan Reservoir also serves as an ecological and recreational area, and serves to protects the water quality of the Chesapeake Bay because it acts as a trap for sediments and pollutants. To protect the different ecosystem services that the reservoir provides, it is critical to continuously monitoring and evaluate its water quality. Reservoir water quality can be affected by the delivery of pollutants from industrial and municipal waste discharges (point sources), as well as, from urban and agricultural runoff (nonpoint sources). Contaminants include nutrients (such as nitrogen and phosphorus), ions, metals, and synthetic organic compounds (SOCs) that can affect human and aquatic health. Different management strategies have been implemented at the Occoquan Reservoir to reduce load of pollutants into the reservoir, particularly to reduce concentrations of nutrients, as excessive nutrients can degrade water quality. Two strategies implemented are the addition of nitrogen, in the form of nitrate, and the installation of an oxygenation system at the reservoir bottom waters. The goal of this study is to assess how current management strategies implemented in the Occoquan Reservoir have affected the water quality from 1973 to 2019, with particular emphasis on the data since 2003. This analysis of the Occoquan Reservoir and its tributary watershed includes the evaluation of the hydrological, meteorological, and morphometric characteristics of the Occoquan Reservoir and Watershed; establishment of long-term trends for water quality constituents; and determination of the productivity (trophic state) of the reservoir. Data from water samples from four different stations located at the reservoir and four stations located throughout the watershed were analyzed for nutrients, principal ions and metals, SOCs, and other water parameters indicative of water quality. Statistical analyses were employed to determine long-term water quality trends (Mann-Kendall test) and relationship between constituents (Principal Component Analysis - PCA). The trophic state of the reservoir was assessed using three methods: Carlson's Trophic State Index (TSI), Vollenweider Model, and Rast, Jones, and Lee's Model. Results indicate the Occoquan Reservoir is eutrophic, or highly enriched with nutrients and productive. However, management strategies employed have improved the water quality and the reservoir continues to improve, though at a slow rate.

This research was conducted to update previous studies of the springs of the Kingdom of Saudi Arabia. Approach: Revisit every spring that was recorded previously to ascertain the current status, water quality and zooplankton communities. Results: fourteen springs out of forty six were still flowing. Several springs in the Eastern Province were structurally changed into manmade pools. Also, one new spring was located and documented in the northwestern region. Zinc and copper in several springs were the common dissolved heavy metals and have had exceeded the safe drinking water standards according to World Health Organization. Fourteen zooplankton taxa was found, seven belonged to phylum Rotifera (four Lecane spp. and three brachionids). Six belonged to subclasses Phyllopoda and Copepoda. The phyllopod, Pleuroxus sp., belongs to suborder Cladocera. The remaining five were copepods: one in the order Cyclopoida (Halicyclops sp.) and four in the order Harpacticoida (Bryocamptus sp., Schizopera sp., Euterpina sp. and Metis sp.). The remaining taxon was an unidentified species belonging to class Ostracoda. Zooplankton species were present in nine of the fifteen springs; the exceptions were Umm Al-Eyal, Abu-Dhuba and the four geothermal springs. Conclusion/ recommendation: The research concluded that the majority of the springs in the Kingdom have fallen dry between 1990 and 2013. Total dissolved solids as well as electrical conductivity, during the same period, were not significantly different. Zooplankton abundance displayed a positive correlation to Electrical Conductivity. Spring water is an important source of freshwater in the Kingdom; as such, springs must be properly maintained and conserved. More attention should be given to protect this important commodity from becoming obsolete. Groundwater protection is everyone's responsibility

Coldwater Lake is a new lake formed when a massive mudflow down the Toutle River Valley, caused by the eruption of Mount St. Helens on May 18, 1980, blocked the natural outlet of Coldwater Creek. This research utilizes physical, biological and chemical data collected at Coldwater Lake during the sun1mers of 1989 and 1990 to calibrate and verify the one-dimensional computer models CE-THERMRl and CE-QUAL-Rl for Coldwater Lake. CE-THERM-R1 was used to simulate thermal characteristics in Coldwater Lake during the summer stratification periods of 1989 and 1990. The model was calibrated to 1989 data and was verified with 1990 data. The model performed well with respect to typical stratification features such as depth and temperature of the epilimnion, gradient of the thermocline and temperature of the hypolimnion. The 1990 verification simulation indicated a lack of heat in the epilimnion and metalimnion towards the end of the summer. This is thought to be a product of inaccurate cloud cover data. Model simulations predicted vertical eddy diffusion coefficients (Ez) throughout the water column. These were compared to Ez values in the hypolimnion calculated from temperature data collected by Kelly (1991). Model simulated Ez values in the hypolimnion were near molecular diffusion while field calculated values were one to two orders of magnitude greater than molecular diffusion. The model simulation assumed no lake inflow or outflow so the hypolimnion was more stable than the natural system. The amount of photosynthetically available radiation (PAR) to Coldwater Lake was determined from output derived from the model simulation. This will be useful in determining primary productivity within the lake. CE-QUAL-R1 was used to simulate water quality in Coldwater Lake. The model was calibrated using dissolved oxygen (D.O.) data collected in 1989. The model adequately predicted the D.O. profile in the hypolimnion but tended to over predict D.O. concentration in the epilimnion by 1.0- 3.0 mg/1. This may be caused by an under estimation of the vertical diffusion coefficient in the model simulation. Mean phytoplankton concentrations were similar to field data in the surface layer assuming a 1 mg/1 phytoplankton to 10 ug/1 chlorophyll a ratio. However, concentrations at 10 m and 20 m were under predicted. The phytoplankton - chlorophyll a comparison may not be valid for these lower regions because a significant portion of algal cells within this region are non-viable and are found as particulate detritus in various stages of decomposition. Model simulated nutrient concentrations were in good agreement with the field data. N03 concentration in the hypolimnion increased slightly throughout the model simulation due to decay of the assumed initial condition of 2 mg/1 refractory dissolved organic matter which was contributed to the lake during the eruption of Mt. Saint Helens on May 18, 1980. The model simulation predicted that the phytoplankton were nitrogen limited. An analysis of potential changes in water clarity and water temperature due to the addition of fish in the summer of 1989 was made. The 1990 model simulation predicted that the addition of 200 kg/hectare of Rainbow Trout had little change on water temperature and water clarity. Collection of further site specific data such as; cloud cover estimates, primary productivity rates and quantity of dissolved organic matter contributed by the May 18, 1980 eruption of Mt. Saint Helens would be useful in building a reliable water quality model at Coldwater Lake.

To the Resolution from the Board of Directions â RDC No 274/05, from the National Agency of Sanitary Vigilance (ANVISA), that approves the âTechnical Regulation for Bottled Water and Iceâ, the salt-added water is a bottled water that is prepared and bottled containing one or more salts, without any addition of sugars, sweeteners, flavors or other ingredients, destined for human consumption. This resolution does not specify the characteristics for identity fixing or the quality of the bottled salt-added water, and has as only requirement that the water used for its prepare is in accord with the microbiological, chemical and radioactive parameters of the âQuality of the Water for Human Consumption Normâ. However, the current Directive No. 2.914/11 from the Ministry of Health does not apply to the salt-added water after its bottling, nor to the water used as raw material for the product. Willing to evaluate the quality of the salt-added water in its two stages of manufacture, (well water, used as raw material and the bottled water, in 20-liter carboys) from salt-added water producer industries from the State of CearÃ, samples were collected in 15 companies, in three distinct periods of time, totalling 270 samples. The microbiological analysis performed were: Determination of Total coliforms and Escherichia coli (Chromogenic substrate technique); Enterococcus, Pseudomonas aeruginosa, Clostridium perfringens (Filtering membrane technique); Heterotrophic bacteria (Culture in Depth technique), and phisico-chemical analysis; Determination of Nitrate, Nitrite (Spectrophotometric method); Residual Chlorine and pH (Electroanalytical measuringIt was verified that the well water used as raw material in 11 (73, 33%) of the 15 companies does not fill the standards of the water potability for human consumption. Regarding the bottled water, it was verified that in 14(93, 33%) of the companies, it does not follow the phisico-chemical and microbiological parameters for mineral water and for water for human consumption. It was concluded that an update in the sanitary legislation of the salt-added water product is necessary and urgent in order to prevent damages on the Health of the consumer population.
Para a ResoluÃÃo da Diretoria Colegiada - RDC N 274/05 da AgÃncia Nacional de VigilÃncia SanitÃria (ANVISA) que aprova o "Regulamento TÃcnico para Ãguas Envasadas e Gelo", a Ãgua adicionada de sais à a Ãgua para consumo humano, preparada e envasada, contendo um ou mais sais, sem adiÃÃo de aÃucares, adoÃantes, aromas ou outros ingredientes. Esta ResoluÃÃo nÃo especifica as caracterÃsticas para fixaÃÃo da identidade e qualidade da Ãgua adicionada de sais envasada, e tem como requisito especÃfico, que a Ãgua utilizada para preparo desse produto atenda aos parÃmetros microbiolÃgicos, quÃmicos e radioativos da Norma de Qualidade da Ãgua para Consumo Humano. Entretanto, a atual Portaria N 2.914/11 do MinistÃrio da SaÃde, nÃo se aplica a Ãgua adicionada de sais apÃs o envasamento, e a outras Ãguas utilizadas como matÃria-prima para elaboraÃÃo de produto. Com o objetivo de avaliar a qualidade da Ãgua em duas etapas de produÃÃo Ãgua bruta (poÃo) utilizada como matÃria-prima e Ãgua envasada (garrafÃes de 20 litros), obtida de indÃstrias produtoras de Ãguas Adicionadas de Sais no Estado do CearÃ, foram coletadas amostras, em quinze empresas e em trÃs perÃodos distintos, totalizando 270 amostras. As anÃlises microbiolÃgicas realizadas foram: determinaÃÃo de coliformes totais e Escherichia coli (tÃcnica de substratos cromogÃnicos); Enterococcus, Pseudomonas aeruginosa, Clostridium perfringens (tÃcnica de membrana filtrante); bactÃrias heterotrÃficas (tÃcnica de cultivo em profundidade) e as anÃlises fÃsico-quÃmicas: determinaÃÃo de nitrato, nitrito (mÃtodo espectrofotomÃtrico); cloro residual e pH (medidas eletroanalÃticas). Verificou-se que a Ãgua bruta utilizada como matÃria-prima em onze (73,33%), das quinze empresas, nÃo atende aos padrÃes de potabilidade da Ãgua para consumo humano. Com relaÃÃo à Ãgua envasada constatou-se que quatorze (93,33%) empresas, nÃo atende aos parÃmetros microbiolÃgicos e fÃsico-quÃmicos para Ãgua mineral natural e Ãgua para consumo humano. Concluiu-se que se faz necessÃria e urgente a atualizaÃÃo da legislaÃÃo sanitÃria do produto Ãgua adicionada de sais envasada, visando à prevenÃÃo de danos a saÃde da populaÃÃo consumidora.

Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol)
The study illustrates the current ecological integrity of the Diep River system, based on the recent river health assessment using the South African Scoring System version 5 (2000-2003) and the water quality data (1996-2002). Some of the major land-use impacts on the river system are highlighted.

Sediment is a leading contributor to nonpoint source (NPS) pollution in streams and rivers. Sources and sinks of sediment movement were identified for a 121-hectare watershed located in Webster County, Mississippi in order to evaluate the impact of forest harvesting on water quality and sedimentation rates. In a completely randomized design containing three replications of two treatments (unharvested vs. harvested) and two slopes (≤9% vs. >9%), twelve sub-watersheds were randomly selected for intensive measurement of the sources and sinks of sediment after precipitation events. In-stream, bank and forest road sediment movement were also monitored pre- and post-harvest. Total suspended sediment (TSS) in runoff from forest roads ranged from 36-188 g/L with a consistent trend of decreasing sediment concentrations with increasing distance from the road. Within the watershed, erosional processes dominated however there was little net change in soil elevation one year post-harvest.

The Chehalis River Basin is located in the southwest region of Washington State, originating in the Olympic Mountains and flowing to Grays Harbor and the Pacific Ocean. The Chehalis River is over 125 miles, exists within five counties, and flows through agricultural, residential, industrial, and forest land areas. Four major rivers discharge to the Chehalis River, as well as many smaller creeks, five wastewater treatment plants, and groundwater flows. Flooding is a major problem in the relatively flat areas surrounding the cities of Chehalis and Centralia, with severe consequences for property, safety and transportation. As a result, construction of a flood-control dam in the upper basin has been proposed. One major concern of constructing a dam is the potentially severe impacts to fish health and habitat. The Chehalis River has routinely violated water quality standards for primarily temperature and dissolved oxygen, and has had multiple water quality and Total Maximum Daily Load studies beginning in 1990. CE-QUAL-W2, a two-dimensional (longitudinal and vertical) hydrodynamic and water quality model, was used to simulate the Chehalis River, including free flowing river stretches and stratified (in summer) lake-like stretches. The goals of this research were to assess the flood retention structure's impacts to water quality, as well as river responses to potential climate change scenarios. In order to use the model to achieve these goals, calibration to field data for flow, temperature, and water quality constituents was performed. This involved developing meteorological data, riparian shading data, and flow, temperature, water quality records for all tributaries during the calibration period of January 1, 2013 to December 31, 2014. System cross-sectional geometry data were also required for the model grid. Because of the short travel time in the river, the model was sensitive to boundary condition data, wind speed, bathymetry, nutrient kinetics, and algae, epiphyton, and zooplankton kinetics. Future conditions showed predictions of warmer water temperatures and slight changes to water quality conditions on the river. As fish in the area prefer cooler water temperatures, this could pose a threat to fish health and habitat. Flood retention structures also showed impacts to river temperature and water quality. Structures with the purpose of flood retention only (only operating during times of flooding) gave model predictions for daily maximum temperature higher than structures that employed flood retention and flow augmentation (operating during all times of the year). This suggested the management of flow passage or retention by the dam is important for water quality on the river. As this research continues improvements will be made, particularly to temperature and water quality constituents. Additional data for the system would be beneficial to this process. Model predictions of temperature were sensitive to meteorological data, including cloud cover, which were largely estimated based on solar radiation. Additional meteorological data throughout the basin would be useful to temperature results. Temperature results were also sensitive to the model bathymetry, and additional investigations into segments widths and water depths may improve temperature predictions. Water quality constituent data were largely lacking for the system. Many estimation techniques and approximations were used for input water quality constituents for the model upstream boundary and tributaries when little or no data were available, introducing uncertainty to the model. It was not possible to calibrate pH to field data because alkalinity data were essentially unavailable. However, other constituents had good agreement between model predictions and field data, including dissolved oxygen, nitrates, total phosphorus, and total suspended solids.

Ett avloppsvatten innehåller olika föroreningar som påverkar recipientens vattenkvalitet. En förorening somreningsverken inte är optimerade för att reducera är mikroorganismer, som i recipienten påverkar bland annatbadvattenkvalitén. Syftet med examensarbetet var att ta reda på hur utvalda processteg i ett reningsverkpåverkar utgående halter av mikroorganismer, hur utsläppen av mikroorganismer kan övervakas och hur mikroorganismernapåverkar recipientens badvattenkvalitet. Examensarbetet har uppfyllt syftet genom att undersökahur biologiska reningssteg reducerar indikatororganismerna E.coli och intestinala enterokocker jämfört medslutreningsalternativen kontinuerligt sandfilter samt skivfilter. Provtagning genomfördes på två reningsverk ochresultatet analyserades för att besvara frågan. Andra kvalitetsparametrar i avloppsvattnet samt flöde, lufttemperaturoch nederbörd har jämförts med utgående koncentration av indikatororganismerna från reningsverk föratt undersöka om det finns några samband som går att använda för att uppskatta det mikrobiologiska utsläppet.För undersökningen har de statistiska metoderna Kendalls Tau och Partial Least Squares använts. En litteraturstudiepå hur implementering av läkemedelsrening med ozon kan desinficera avloppsvattnet, vilken doseringsom krävs och vad den bör baseras på har genomförts. Efter avloppsutsläpp i en recipient sprids mikroorganismernamed vattnets strömmar och mikroorganismerna dör normalt av med tiden. Denna avdödandeprocesskan beskrivas med en ekvation av första ordningens kinetik. Ekvationens känslighet för variation i variablernasolinstrålning, temperatur, siktdjup och tid har undersökts. Ekvationen har även använts för en fallstudie av avloppsutsläppvid bräddning och hur det påverkar en badplats nedströms. För fallstudien fanns information omflödestid, utspädning och nedbrytningsvariablerna att tillgå. Undersökningen visar att biologisk rening med biobädd reducerar indikatororganismerna effektivast av de undersöktareningsstegen. Sandfiltrets reduktionsförmåga var god men skivfiltret presterade sämre. Från provtagningenframkom också att koncentrationen av E.coli är konsekvent högre och reduceringen sämre än motsvarandeför intestinala enterokocker. Indikatororganismernas koncentration i utgående avloppsvatten är enligtkorrelationsanalysen slumpmässig och inget signifikant och starkt samband fanns till de undersökta parametrarna. På grund av detta är uppskattning av mikrobiologiska utsläpp med hjälp av mätning av andra parametrarinte tillförlitlig. Den genomförda litteraturgranskningen av ozondosering visar att dosen som krävs för desinfektionav avloppsvatten behöver anpassas för varje reningsverk samt att resultat från forskningen går isär omhur doseringen bör optimeras. I recipienten har siktdjupet störst betydelse för nedbrytningen och recipientensegenskaper är viktigare än utsläppets storlek för vattenkvalitén enligt den modell som använts. Fallstudien visadeatt även vid bräddning på reningsverket hinner mikroorganismerna spädas ut och brytas ner tillräckligt föratt badvattenkvalitén inte ska klassas som otjänlig vid närliggande badplats.
Depending on the efficiency of the processes used in a wastewater treatment plant, the recipient receives watercontaining various concentrations of microorganisms. These microorganisms might infect people using therecipient for recreational purposes. The thesis aims to investigate how some process choices affect the concentrationsof microorganisms in sewage and how the concentration can be monitored with the use of other waterquality measurements. Lastly the microbial degradation after discharge in a lake was investigated. Process choiceswere evaluated through sampling before and after two biological treatment steps, one sand filter facilityand one disc filter facility. The obtained results demonstrate that among the investigated alternatives, a biologicalstep using biofilm is the most efficient for removing microorganisms, followed by sand filtration and leastefficient with high variability was disc filtration. The literature review suggests that the use of ozonation forreducing pharmaceutical residues could be efficient in reducing microorganisms, but the required dosage is notuniformly established in previous research. Statistical analysis on water quality measurements with Kendall’sTau and Partial Least Squares did not appear to be a good substitute to use for monitoring and prediction ofbacterial concentrations. The water quality of the recipient, especially the transparency for UV-light, is moreimportant for maintaining good bathing water quality than the outflow concentration of microorganisms in thesewage. In a small case study, it was shown that an official bathing site is not at risk for acute microbiologicalcontamination even when extreme rainfalls causes overflow in the upstream waste water treatment plant.

CE-QUAL-W2 is a 2-D hydrodynamic and water quality model that has been applied to reservoirs, lakes, river systems, and estuaries throughout the world. However, when this model is applied for shallow systems, this model requires a long calculation time to maintain numerical stability, compared to applications of reservoirs or deeper river systems. To solve this problem, a new hydrodynamic and temperature model was built based on the framework of CE-QUAL-W2 but that allows for steady-state hydrodynamic computations. By calculating the hydrodynamics at steady-state, the time step for stability is relaxed and simulations can proceed at much higher time steps. The rest of the model framework is still used for water quality state variables, in this case, temperature. The algorithm used for computing the water surface elevation is Manning's equation. This thesis study is one part of the Willamette Water 2100 project (Santelmann et al., 2012), which examines hydrological, ecological, and human factors affecting water scarcity in the Willamette River Basin. This study included three stages: (1) Convert six existing CE-QUAL-W2 V3.1 models into a newer version: CE-QUAL-W2 V3.7. (2) Develop the steady-state model code in FORTRAN. (3) Test the steady-state model on three river systems in the Willamette River Basin at Year 2001 and 2002. The result proved that the steady-state model could reduce the computing time by 90% for river applications, while predicting dynamic river temperature with high accuracy at a two-minute time scale. This new model will be employed to simulate the future of the Willamette River System at a decadal or centennial timescales, addressing river temperature concerns and fish habitat issues.

Located in central Washington State, Banks Lake serves as an irrigation storage reservoir for the Columbia Basin Irrigation Project and is home to a diverse fisheries population. The current hydrologic management strategies used for Banks Lake have been chosen to serve two purposes: to adequately store and provide irrigation water for the Columbia Basin Irrigation Project and to maintain a healthy aquatic environment suitable for the growth and habitation of local flora and fauna. Increased needs for irrigation water within arid central Washington poses additional challenges to reservoir managers so that irrigation needs are met without damaging the present aquatic environment within Banks Lake. Future plans by the Washington Department of Ecology to use Banks Lake storage to replenish ground water reserves of the Odessa Subarea aquifer have required an investigation into how increased seasonal drawdown may affect fish growth, fish habitat and overall limnology of Banks Lake. The goal of this project is to produce a hydrodynamic and water quality model of Banks Lake that can predict the impacts of management strategies on the lake's water quality and the linkage of lake management to fish habitat.

Temperature, conductivity, and Aeromonas hydrophila density were determined bimonthly at six sites in the White River drainage system, Delaware County, Indiana, from April, 1984 through December, 1984. Fish were collected from four of the six sites. Fish were identified to species, examined for gross pathology, and their blood collected. Titers against A. hydrophila antigen 157 were determined for all carp (Cyprinus carpio) captured. Certain carp serum samples were also tested against three additional A. hydrophila antigens.Aerononas hydrophila densities appeared to be related to temperature and conductivity, primary producers, and runoff/effluent. Aeromonas hydrophila densities were higher in areas affected by urban runoff/ effluent than in areas affected by rural runoff/effluent. Aeromonas hydrophila densities increased as one progressed through the city of Muncie.Only five percent of all fish captured exhibited signs of gross pathology. Diseased fish typically demonstrated low titers against antigen 157. Several A. hydrophila serotypes were apparently infectious for the carp studied. Thirty-two percent of the carp sampled exhibited a positive titer response against antigen 157. Considerable variation in titer response existed between individuals.Ball State UniversityMuncie, IN 47306

Para suprir a carÃncia hÃdrica, o Cearà dispÃe de uma grande rede de reservatÃrios artificiais destinados aos mais diversos usos. PorÃm, Ãguas que permanecem reservadas em aÃudes sÃo limnolÃgicamente vulnerÃveis, sendo o fenÃmeno da eutrofizaÃÃo uma das piores consequÃncias resultantes das atividades antrÃpicas desenvolvidas nas Ãreas de contribuiÃÃo desses reservatÃrios, consequÃncias essas que sÃo agravadas ainda mais em funÃÃo das caracterÃsticas naturais do semiÃrido, um ambiente marcado por baixas precipitaÃÃes pluviomÃtricas e pela sua mà distribuiÃÃo no espaÃo e no tempo. Para auxiliar no estudo trÃfico dessas Ãguas, hà muito vem sendo utilizada pelos limnÃlogos uma ferramenta destinada a classificar os recursos hÃdricos no tocante ao seu estado de trofia, o IET - Ãndice do Estado TrÃfico, desenvolvido por Carlson (1977). A pesquisa aqui desenvolvida consistiu em aprimorar o estudo da correlaÃÃo entre os parÃmetros de Clorofila a, fÃsforo total e TransparÃncia de Secchi, utilizados na composiÃÃo do IET, bem como ajustar a escala logaritmica do Ãndice, basaeando-se nas medidas mÃnimas e mÃximas de Secchi para os reservatÃrios de Ãgua do CearÃ, o que resultou em uma metodologia de classificaÃÃo trÃfica adaptada Ãs condiÃÃes dos sistemas lÃnticos inseridos no semiÃrido cearense.
To meet the water shortage, Cearà has an extensive network of artificial reservoirs intended for various uses. However, waters that remain reserved in dams present limnological vulnerability, and the phenomenon of eutrophication is one of the worst consequences of anthropic activities developed in the areas of contribution of these reservoirs, consequences that are aggravated due to the natural characteristics of semiarid, an environment marked by low rainfall and its poor distribution in space and time. To assist the trophic study of these waters, it has long been used by limnologists a tool to classify water resources in relation to their trophic state, the TSI - the Trophic State Index, developed by Carlson (1977). The research conducted here was to enhance the study of the correlation among the parameters of chlorophyll a, total phosphorus, and Secchi Transparency, used in the composition of the TSI, as well as to adjust the logarithmic scale of the index, according to Secchi's maximum and mi nimum measures to the water reservoirs of CearÃ, which resulted in a trophic classification methodology adapted to the conditions of the inserted lentic systems in Cearà semiarid

Many communities are currently seeking to balance urban water needs with preservation of sensitive fish habitat. As part of that effort, CE-QUAL-W2, a hydrodynamic and temperature model, was developed for Chester Morse Lake and the lower Cedar River, WA. Chester Morse Lake is approximately 10 km long with a maximum depth at full pool of 40 m. The Cedar River model started immediately downstream of the Chester Morse dam and ended 21 km downstream at Landsburg, where drinking water is diverted for the City of Seattle. This water quality model was coupled with a fish habitat and bioenergetics model for bull trout and was calibrated to temperature data between 2005 and 2008. Bull trout fish bioenergetics parameters were provided by the USGS. The CE-QUAL-W2 model was found to be highly accurate in modeling temperature variation in the lake - at most locations having an average absolute mean error of between 0.5 and 0.8 oC. The Cedar River model had an average absolute mean error of 0.7oC. This tool is designed to allow managers and operators to estimate the impact to fish habitat and growth potential from various management decisions including extent of drawdown, timing/volume of flows, and various pumping operations. Future studies could include incorporating further water quality parameters such as nutrients, algae, and zooplankton as they relate to fish productivity.

Doutoramento em Biologia
A Directiva Quadro da Água (DQA) foi introduzida pela União Europeia (UE) em 2000 com o objetivo de proteger as águas de superfície (interiores, de transição e costeiras) e subterrâneas. Esta ambiciosa directiva lançou novos desafios, entre os quais a necessidade de desenvolver novas ferramentas ecotoxicológicas para a avaliação do estado ecológico das massas de água. O tributilestanho (TBT), um biocida amplamente utilizado em tintas antiincrustantes e identificado como agente causador do fenómeno de imposex / intersex em gastrópodes, está incluído na lista de substâncias prioritárias da DQA. No entanto, esta directiva não considera qualquer ferramenta de biomonitorização específica para avaliar os efeitos nocivos do TBT nos ecossistemas. O único objetivo concreto para esta substância é referido nas Normas de Qualidade Ambiental (NQA) e atingido a 0,2 ng TBT / L (NQA - Média Anual). Mais tarde, em 2008, a Directiva Quadro da Estratégia Marinha (DQEM) foi introduzida na UE com objectivos semelhantes à DQA, mas direcionada para águas marinhas. No entanto, uma vez mais, não foi proposta nenhuma ferramenta ecotoxicológica para a monitorização dos efeitos biológicos provocados por este poluente. Assim, de forma a integrar a biomonitorização da poluição por TBT ao abrigo destas directivas, esta tese tem como objetivo desenvolver e testar, sob diferentes cenários, ferramentas baseadas nos biomarcadores imposex/intersex para avaliar o estado ecológico de massas de água. Assim, é proposto um sistema de classificação baseado nos níveis de imposex/intersex de populações de gastrópodes para avaliar o estado ecológico de águas costeiras e de transição, relativamente à poluição por TBT. Utilizando a Ria de Aveiro (NW Portugal) como estudo de caso, três bioindicadores - os gastrópodes Nucella lapillus, Nassarius reticulatus e Littorina littorea - foram utilizados tendo em conta o elemento de qualidade biológica para invertebrados bentónicos da DQA, de forma a classificar o estado das massas de água desta região. O índice de sequência do vaso deferente (VDSI) e o índice de intersex (ISI) foram os parâmetros de imposex/intersex selecionados para avaliar o estado ecológico, relativamente à poluição por TBT. Os limites definidos pelos Rácios de Qualidade Ecológica (EQR) foram obtidos para cada espécie, a fim de definir as cinco classes de estado ecológico (Excelente, Bom, Razoável, Medíocre e Mau). A espécie N. lapillus é proposta como bioindicador chave na monitorização da poluição por TBT, no entanto, o uso combinado das outras espécies revela-se muito útil porque permite monitorizar uma área maior e uma maior diversidade de habitats. Esta ferramenta de monitorização multiespecífica demonstrou ser bastante útil para avaliar a evolução temporal do estado ecológico das massas de água da Ria de Aveiro entre 1998 e 2013, que demonstrou uma clara melhoria, alcançando um bom estado ecológico em 2013. Este trabalho propõe também uma outra ferramenta destinada a avaliar a qualidade dos sedimentos. Esta ferramenta consiste num bioensaio em que se expõem fêmeas de N. reticulatus a sedimentos recolhidos no ambiente para determinar se ocorre um aumento de imposex. Este bioensaio provou ser uma ferramenta complementar e com relevância ecológica na monitorização da poluição por TBT na medida em que fornece informação sobre a fracção biodisponível de TBT nos sedimentos e permite avaliar locais onde não existem bioindicadores disponíveis. Para testar o uso de ambas ferramentas em programas de monitorização da DQA, estas foram aplicadas em dois sistemas estuarinos - Minho e Lima - localizados no Norte de Portugal. A monitorização de imposex evidenciou um bom estado ecológico no Minho mas o estuário do Lima não conseguiu alcançar o objetivo de bom estado ecológico, apresentando locais com um estado "moderado" ou de qualidade inferior. Em conformidade, o bioensaio com sedimentos confirmou a presença de TBT biodisponível apenas nos sedimentos do estuário do Lima, já que se observou o aumento de alguns parâmetros de imposex com estes sedimentos. O uso combinado destas ferramentas permitiu aumentar a área de monitorização nestes sistemas estuarinos, uma vez que não foi possível encontrar bioindicadores em todas as estações de amostragem, sendo nesse caso obtidas apenas amostras de sedimento. O critério proposto para a monitorização de imposex na DQA foi também testado ao longo da costa portuguesa de forma a avaliar a evolução do estado ecológico de 2000 a 2014. Em 2014, as fêmeas de N. lapillus colhidas em praias ao longo da costa exibiram baixos níveis de imposex, exceto numa estação situada na Zambujeira do Mar (SW Portugal) onde foram encontradas fêmeas estéreis. Já as fêmeas de N. reticulatus mostraram baixos níveis de imposex na maioria das estações amostradas, porém elevados níveis foram observados em áreas sujeitas a um intenso tráfego naval. Comparando estes valores com os observados em anos anteriores, é possível perceber que ambas as espécies recuperaram de forma significativa ao longo dos últimos 15 anos. N. lapillus apresentou uma redução dos níveis de imposex mais pronunciada do que N. reticulatus, porém esta diminuição parece ter abrandado nos últimos anos (2011-2014), prevendo-se uma estabilização por algum tempo em níveis muito baixos. N. reticulatus também mostrou uma diminuição gradual, mas os valores de imposex indicam uma recuperação mais lenta em portos de pesca e marinas. Isto representa uma mudança das principais fontes de poluição por TBT, já que os níveis de imposex em grandes portos comerciais, outrora locais altamente poluídos, caíram rapidamente. Assim, na costa Portuguesa, o bom estado ecológico foi alcançado na maior parte das estações localizadas em águas costeiras, no entanto uma qualidade ecológica inferior foi observada em massas de água de transição, especialmente onde estão localizados portos de pesca e marinas. A classificação da qualidade ecológica da costa portuguesa segundo a DQA (proposta apresentada nesta tese) e a OSPAR, relativamente à poluição por TBT, é analisada no presente trabalho. Esta comparação é da maior importância, pois tanto as premissas da DQA, como as ferramentas de monitorização utilizadas pelas convenções regionais marinhas (por exemplo a OSPAR) devem ser integradas na aplicação da DQEM. As classificações obtidas segundo a DQA e a OSPAR apresentam um resultado global muito semelhante para 2014, e ambas denotam uma apreciável recuperação do estado ecológico ao longo dos últimos anos. A integração da monitorização de imposex/intersex na DQEM é aqui recomendada e discutida, tendo em conta possíveis divergências nos objetivos definidos por cada legislação e os meios para alcançá-los. Mesmo que a utilidade das ferramentas empregadas para monitorizar a poluição por TBT tenham sido comprovadas, a monitorização de imposex/intersex a ser aplicada na DQA e DQEM só será eficaz se: (i) houver uma boa escolha de bioindicadores; (ii) o imposex/intersex constituírem uma resposta específica para a poluição por TBT porque se outros contaminantes tiverem a capacidade de induzir imposex ou intersex, estes biomarcadores perdem grande parte do seu valor operacional. Por estas razões, esta tese apresenta ainda alguns resultados que devem ser considerados para a validação da utilização do imposex/intersex na monitorização da poluição por TBT. A Ria de Aveiro é uma área que tem sido intensamente estudada em relação à poluição por TBT e, conforme descrito anteriormente, apresentou uma importante melhoria do estado ecológico em relação a este poluente prioritário. No entanto, uma tendência contrária foi observada na evolução dos níveis de imposex no gastrópode Peringia ulvae. Esta espécie - considerada por vários autores como um bom bioindicador da poluição por TBT - não demonstrou uma recuperação dos níveis de imposex, apesar dos níveis de TBT e de imposex/intersex noutras espécies terem vindo consistentemente a diminuir nesta área. Em vez disso, houve um aumento global na percentagem de fêmeas afetadas por imposex e nos níveis de VDSI até 2012, sendo que os níveis de imposex em 2015 são ainda semelhantes aos encontrados em 1998. As possíveis razões para o padrão contracorrente observado nesta espécie podem estar relacionados com a interferência de outros factores que influenciam a expressão do imposex; por exemplo, a indução de imposex por parasitas - que são difíceis de controlar quando a monitorização é realizada com esta espécie - pode enviesar a interpretação dos resultados. É, portanto, necessária uma escolha criteriosa dos bioindicadores a utilizar no âmbito das directivas DQA e DQEM. O imposex não é apenas um efeito exclusivo do TBT, uma vez que já foi descrito que o trifenilestanho (TPT) pode também causar este fenómeno em algumas espécies de gastrópodes. Aqui, é descrita, pela primeira vez, a indução de imposex por TPT em N. lapillus, a espécie que foi proposta como bioindicador chave na DQA. Curiosamente, o desenvolvimento do imposex em fêmeas de N. lapillus injetadas com TPT é diferente das injectadas com TBT, uma vez que as primeiras desenvolvem uma via de imposex principalmente afálica (sem desenvolvimento do pénis). Estes resultados sugerem que o TPT e o TBT podem agir de forma diferente no processo de masculinização de fêmeas de gastrópodes, lançando novas perspectivas sobre as hipotéticas vias subjacentes ao desenvolvimento de imposex. É importante saber se existem outros contaminantes, para além dos organoestânicos, capazes de induzir (ou interferir com) o desenvolvimento de imposex ou intersex, com vista à validação das ferramentas de monitorização propostas nesta tese. Para tal, um ensaio com um gene repórter foi realizado em células transfectadas com recetores humanos, cujos ortólogos foram anteriormente identificados em gastrópodes (RXR, PPAR, ER e RAR). Sabendo que o imposex é causado pela ativação dos recetores nucleares RXR e PPARy por parte do TBT e TPT, é importante perceber se outros contaminantes são capazes de ativar estes recetores. Testaram-se vários contaminantes ambientais e mesmo que algumas substâncias tenham tido a capacidade de ativar ligeiramente o RXR e PPARy, nenhuma foi capaz de o fazer com uma potência semelhante ao TBT e TPT, sugerindo que estas são as únicas substâncias testadas capazes de induzir imposex para concentrações ambientalmente relevantes. Não obstante, todas as substâncias que foram capazes de ativar os recetores foram identificadas e o seu potencial para causar disrupção endócrina nos gastrópodes é discutido. Em conclusão, as ferramentas propostas nesta tese podem ser extremamente úteis na monitorização do ambiente aquático ao abrigo das recentes directivas da União Europeia. Em Portugal existem três peças legislativas que se sobrepõem espacialmente nas águas costeiras (DQA, DQEM e OSPAR) e águas de transição (DQA e OSPAR), e podem diferir nos seus objetivos específicos relativamente à poluição por TBT. Logo, existe uma necessidade urgente de encontrar objetivos comuns na UE, tanto químicos e biológicos, para este poluente. Para além disto, e num momento em que a busca de modelos biológicos não vertebrados está a aumentar em ecotoxicologia, esta tese realça o uso de gastrópodes como uma possível opção. O trabalho desenvolvido nesta tese mostra que a poluição por TBT tem vindo a diminuir em Portugal mas ainda existem alguns locais onde os níveis são altos e não atingem os objectivos definidos pela OSPAR e pela DQA (segundo a proposta aqui apresentada). As ferramentas propostas nesta tese podem ser úteis para acompanhar a evolução da situação em Portugal e na UE nos próximos anos e identificar os locais onde será necessário melhorar a qualidade ecológica das massas de água relativamente a esta substância prioritária, de acordo com as metas estabelecidas pela legislação vigente.
The Water Framework Directive (WFD) was introduced in the European Union (EU) in 2000 with the objective to protect the EU surface waters (inland, transitional and coastal) and ground waters. This ambitious directive raised new challenges, as the need to develop quick and low-cost effect-based monitoring tools, which are increasingly being recommended to perform a proper environmental assessment under this directive. Tributyltin (TBT), a biocide largely used in antifouling paints and identified as a causative agent of imposex/intersex in gastropods, is listed as a priority substance in WFD. However, this directive does not consider any particular biomonitoring tool to assess TBT deleterious effects on the ecosystems. The only explicit objective for TBT regards the Environmental Quality Standard (EQS – Annual Average = 0.2 ng TBT/L). Later on, in 2008, the Marine Strategy Framework Directive (MSFD) was introduced in the EU with similar objectives but specifically related to marine waters that again failed to propose an effect based tool to monitor this pollutant. Therefore, to integrate TBT pollution monitoring within these legislative frameworks, it is the aim of this thesis to develop effect based tools centred on the imposex/intersex biomarkers in order to assess the ecological quality status of EU water bodies regarding TBT pollution. This work proposes a scoring system based on imposex/intersex levels to assess the WFD ecological quality status regarding TBT pollution of transitional and coastal waters. Taking Ria de Aveiro (NW Portugal) as a case study, three bioindicators – the gastropods Nucella lapillus (dog-whelk), Nassarius reticulatus (netted-whelk) and Littorina littorea (periwinkle) - were used under the general WFD benthic invertebrate quality element to classify the ecological status of this area. The vas deferens sequence index (VDSI) and the intersex index (ISI) were selected as biomarkers to assess the condition of this quality element regarding the impact of TBT pollution. EQR boundaries were set for each species in order to define the five ecological status classes (High, Good, Moderate, Poor and Bad). N. lapillus is proposed as a key bioindicator species, however the combined use of further species is very useful to cover a wider monitoring area and a higher diversity of habitats. This multi-species monitoring tool was useful to assess the temporal evolution of the ecological status of Ria de Aveiro water bodies between 1998 and 2013, showing that all the surveyed area improved and reached a good ecological status in 2013. This work also proposes other imposex based tool that allows to evaluate the sediment quality, regarding TBT pollution. The use of this bioassay has proven to be a practical and ecological relevant tool as (i) it can give information for sites with no native populations of snails, (ii) it provides early identification of polluted sites anticipating future imposex levels or early identification of recovering, and (iii) it yields information on the bioavailable fraction of the TBT in the sediment. Therefore, this tool can also be of extreme usefulness under the scope of recent European legislative frameworks. To confirm the suitability of the above mentioned tools in WFD monitoring programs, they were both applied in two estuarine systems - Minho and Lima - located in NW Portugal. The imposex field monitoring evidenced a good ecological status in Minho while the Lima estuary fail to reach the WFD good ecological status objective by presenting sites with “Moderate” and “At Best Poor” ecological status. Accordingly, the sediment bioassay confirmed the presence of bioavailable TBT only in the Lima sediments. The combined use of these tools allowed to increase the monitoring area in these estuarine systems and enhanced the robustness of the assessment, as the bioindicators fail to exist at many sites of the study area. The proposed criteria for imposex monitoring under the WFD was tested along the Portuguese coast to assess the evolution of the ecological status from 2000 to 2014, using N. lapillus and N. reticulatus as bioindicators. Lately, the dogwhelks collected in coastal shores exhibited low imposex levels, except at one station in Zambujeira do Mar (SW Portugal) where sterile females were still found. Accordingly, the netted-whelk showed low levels of imposex at the majority of the sampled stations but high levels were still observed at areas subjected to intense naval traffic. When comparing these data regarding the most recent years with past imposex levels, it is perceived that both species recovered significantly over the last 15 years. N. lapillus presented a more pronounced decrease in imposex levels than N. reticulatus, however this declining trend decelerated from 2011 to 2014. N. reticulatus also showed a gradual decrease but the imposex values indicate a slower recovery at fishing harbours and marinas, which represents an apparent shift in the TBT hotspots as imposex levels in large commercial ports fell rapidly. Consequently, in the Portuguese coast a good ecological status was achieved in most of the stations located in coastal waters while a worse ecological quality was observed in transitional water bodies where fishing ports and marinas are located. A comparison between the proposed WFD imposex tool and the OSPAR Assessment Criteria for imposex shows that both classifications schemes present a general similar result for 2014 and point to a clear recovery of the quality status over the years. This comparison between two legislations is of foremost importance since both WFD premises and Regional Sea Conventions (e.g OSPAR) knowledge and monitoring tools should be integrated by member states on the application of the MSFD. Therefore the imposex/intersex monitoring integration within MSFD is discussed taking into account possible divergences between the objectives defined by each piece of legislation and the means to achieve it. Even if the usefulness of the employed tools to monitor TBT pollution has been proved, the WFD’s monitoring proposal will only be effective if: i) there is a good choice of the bioindicators species; and ii) imposex/intersex are specific responses to TBT pollution, i.e., if other contaminants induce imposex or intersex, then these biomarkers lose much of their operational value. For that reason this thesis presents novel information regarding these aspects in order to validate this methodology and better interpret the obtained results. Ria de Aveiro is an area that has been intensively studied regarding TBT pollution and, as previously reported, presented a major improvement of the ecological status regarding this priority pollutant. An opposite trend has been however observed in the imposex evolution in the gastropod Peringia ulvae. This species - regarded by some authors as a good bioindicator of TBT pollution - did not show an imposex recovery despite the fact that TBT levels have been consistently decreasing in this area. Instead, there was a global increase in the percentage of females affected by imposex and VDSI levels until 2012, and the imposex levels in 2015 were similar to those found in 1998. Possible reasons for this counter current pattern could be related with other factors that can influence imposex expression, such as parasitism, that probably cannot be totally controlled when monitoring is performed with this species. Hence, there is the need to carefully choose the right bioindicators to implement TBT monitoring assessments under WFD or MSFD, and P. ulvae is not recommended for this purpose. Imposex is not an exclusive response to TBT since triphenyltin (TPT), a related organotin, is already known to cause the same phenomenon in some gastropod species. This thesis describes, for the first time, that TPT also induces the development of imposex in N. lapillus, the species considered the key bioindicator in the WFD monitoring proposal. However, imposex development in TPT-injected females followed mostly an aphallic route (no penis development). These results suggest that TPT and TBT may act differently in the sequential process of female masculinization casting new insights about the hypothetical pathways underlying imposex development. Besides TBT and TPT, it is important to know if other environmental contaminants can induce or interfere with the imposex/intersex development to ensure that the proposed tools are specific to organotin pollution. With this purpose, a reporter gene assay was performed using the GAL4/UAS system in cells transfected with human receptors, which were already identified in gastropods: Retinoid X Receptor (RXR), Peroxisome Proliferator-Activated Receptor gamma (PPARγ), Retinoic Acid receptor (RAR) and Estrogenic Receptor (ER). It has been reported in the literature that imposex is caused by the activation of the nuclear receptors RXR and/or PPARγ by TBT or TPT, and therefore if other contaminants can bind these receptors they could have the potential to induce imposex/intersex as well. Even if there were other substances that slightly activated RXR and PPARγ, none was able to do it with similar potency than the organotins (TBT and TPT), suggesting so far that these are the only tested substances capable to induce imposex at realistic environmental concentrations. Nevertheless, all substances that were able to activate the reporter gene were identified and their potential to cause endocrine disruption in gastropods is discussed. Concluding, the tools proposed in this thesis can be of extreme utility to monitor the aquatic environment under the frame of the recent EU directives. Moreover, in Portugal there are three legislative pieces that are spatially overlapped regarding coastal waters (WFD, MSFD and OSPAR) and transitional waters (WFD and OSPAR), and they may differ in their specific objectives regarding TBT pollution. Therefore there is a need to find common EU objectives, both chemical and biological, for this pollutant. Furthermore, in a time where the search of non-vertebrate biological models in ecotoxicology is increasing, this thesis enhances the use of gastropods as an option. Also the work here developed shows that TBT pollution has been decreasing in Portugal but there are some sites where levels are still high. In this scenario, the tools here proposed can be useful to track the evolution of TBT pollution during the next years and to identify waters bodies that will require an action to improve their ecological status.

Thesis (M. Tech. (Environmental Health)) -- Central University of technology, Free State, 2013
Introduction: Drinking water of poor quality can cause a variety of diseases and may even result in death. The impact of poor drinking water is a course for concern even in South Africa. Therefore, the physical, chemical and microbiological drinking water quality was investigated in the peri-urban area of Bainsvlei and the Woodlands Hills Estate in Bloemfontein, Free State. Materials and Methods: The water quality was assessed in 20 identified sampling sites for three series with ten weeks apart. These sites use treated municipal and untreated borehole water for drinking. The determinants analysed for were pH, electrical conductivity (EC), turbidity, temperature, Ca, Mg, Na, F, Cl, N, SO₄,N, Free chlorine, Al, As, CN, Fe, Mn, Pb, Hg, total coliforms and E. coli. The water samples were collected and analysed on site and in the laboratory. Both the physical and chemical determinants were measured using standard methods whereas the microbiological determinants were measured using the Defined Substrate Technology (DST) method. The measurements were first compared to the SANS 241 (2011) for compliance. The ANOVA tests were used to investigate if any seasonal variations existed in the water quality as well as to compare the levels of the determinants between borehole and municipal water. In the assessment of the overall drinking water quality of different water sampling sites the water quality index (WQI) was used. Results and Discussions: Significant effects were believed to exist if the p-values of the ANOVA and Scheffe tests were at a significance level of 5% (p < 0.05). The study results revealed that of the four physical determinants that were measured turbidity exceeded the standard in many sampling sites in the three series. Of all the chemical determinants, nitrates exceeded the standard. In the same way coliforms exceeded the standard in a number of sampling sites while E. coli was found in a few sampling sites in the first series. ANOVA tests revealed that seasonal variations existed between pH, EC, temperature, cyanide and iron at a significant level of 5% (p < 0.05) while the Post-hoc Scheffe test further revealed the series in which the effect existed. Similarly, the ANOVA tests revealed that the levels of the determinants between municipal versus borehole varied in pH, EC, Ca, Mg, Na, F, Cl, N, and SO₄ at a significant level of 5% (p < 0.05). The WQI showed that in all the series when combining the good and excellent category season 2 had the highest percentage of 80%, followed by season 3 with 79% and season 1 with 70%. Only borehole sampling sites were found in the poor, very poor and unsuitable categories. Similarly all the highest WQI values were found in borehole sampling sites. Conclusion: This study revealed that the water quality is of good quality in the Bainsvlei and Woodlands Hills Estate of the Mangaung metropolitan municipality in Bloemfontein, in the Free State, South Africa. The presence of E. coli, though found in a few sampling sites and the high levels of turbidity, nitrates and coliforms are of concern to public health.

Excessive nutrient loading of natural and artificial lakes has led, in some systems, to plethoric algal and aquatic macrophyte growth which can result in aesthetic degradation and undesirable tastes and odors. It would be advantageous to have some indication of the potential trophic status of a reservoir before it is filled. An objective of this study was to assess the water quality and nutrient loading potential of the tributaries entering Ray Roberts Lake, a large reservoir located in north central Texas. Samples from a maximum of thirteen sites were collected on the Elm Fork, Trinity River, Isle duBois Creek, and five additional tributaries. Data were also collected during six storms, from atmospheric deposition collectors, and from soil-water microcosms. The relationship between watershed landuse and mean water nutrient concentrations was evaluated. Significant differences will exist between the two major arms of Ray Roberts Lake: Elm Fork, Trinity River and Isle duBois Creek. While the majority of the annual phosphorus and nitrogen load entering both tributaries is coming from overland flow, the proportion is higher in Isle duBois Creek. Point sources in the Elm Fork contribute a larger percentage of the bioavailable phosphorus, which is significantly greater than in Isle duBois Creek. The water quality of Isle duBois Creek, especially nitrogen, is affected to a greater degree by the landuses in its watershed. Predictive regression models made accurate estimations of stream nutrient concentrations in Isle duBois Creek. The entire reservoir, upon reaching equilibrium conditions, will be classified as a eutrophic lake. The Trinity arm, with a higher phosphorus load, will display a higher trophic status. The Isle duBois arm has a lower phosphorus load which will give it a lower trophic status. The long hydraulic residence time of the two arms of the reservoir will remove nutrients upstream of the main body, thus contributing to overall better water quality in the main body of the reservoir.

A series of pond and tanks studies were conducted to determine if compensatory growth (CG) could be elicited in hybrid striped bass (HSB; Morone chrysops x M. saxitilis) through manipulations in feeding that involve sequential cycles of feed deprivation followed by daily satiation feeding. Growth, feed efficiency (FE), hepatosomatic index (HSI), intraperitoneal fat ratio (IPF), and condition factor (CF) were assessed at intervals throughout the growth trials to characterize the nutritional status (catabolic state) and CG response of HSB. Measurements of pituitary growth hormone (GH) cell activity (gene expression, protein stores), and plasma GH were assessed in tank studies to identify the potential catabolic and anabolic role of this growth promoting hormone during feed deprivation and CG. Lastly, the effects of the cyclic feeding regimes on water quality were assessed in ponds trials. In each of the three studies, growth compensation, defined by growth rates that exceed that of control fish fed daily, was observed when treatment fish were realimentated to a control daily satiation feeding following a period of feed deprivation. Cyclic feeding increased overall FE of treatment fish over the controls by 10.8-40.0 % in the first pond study (HSB fingerlings), and 7.0-8.5% in the second pond study (HSB food fish) but not in the tank study. Hepatasomatic index and CF varied significantly with feed deprivation and refeeding, and were useful predictors of the CG response following feed deprivation. There was an inverse relationship between all GH measurements and nutritional status, with no reported compensatory changes in GH. Changes in water quality parameters due to cyclic feeding were only observed in the pond study with HSB food fish. Ponds subjected to the cyclic feeding regimes had 25-38 % lower levels of total phosphorus, 23.9-41.3 % less soluble reactive phosphorus, and 11.6-27.8% less chlorophyll-a. Based on these results, CG can be repeatedly induced in HSB in both ponds and tanks, albeit full growth compensation was not achieved under the cyclic feeding conditions used in these studies. Regardless, these studies suggest that cyclic feeding can improve overall FE and water quality in pond-raised HSB. Further studies are required to ascertain the optimal catabolic conditions needed to induce full growth compensation during HSB production.

In this study, the water quality of Sweet Briar Lake was tested to determine the trophic state of the lake and to determine if the lake can support aquatic organisms. Water samples were collected from two locations at different depths. Samples were collected once a month for six months. Six tests were conducted to help determine the trophic state and water quality of the lake. The tests conducted were nitrogen concentration, phosphorus concentration, Chlorophyll-a concentration, Secchi disc transparency, dissolved oxygen levels and water temperature. Total nitrogen at both locations ranged from 1.767 mg/L to 3.340 mg/L. Total phosphorus at both locations ranged from 0.086 mg/L to 0.724 mg/L. Chlorophyll-a concentrations at location 1 ranged from 0.0176 mg/L to 0.0412 mg/L and location 2 ranged from 0.00834 mg/L to 0.0147 mg/L. Secchi disc transparency at location 1 ranged from 0.4 m to 0.6 m and location 2 ranged 0.6 m to 1.75 m. Oxygen levels did not fall below 2 mg/L except at location 2, during the months of June and July. All tests indicated that Sweet Briar Lake was highly eutrophic to hypereutrophic. Oxygen levels in the lake are adequate to support aquatic organisms.

The current dissertation is motivated by the need for an improved understanding of aerosol water interactions both in subsaturated and supersaturated atmospheric conditions with a strong emphasis on air pollution and climate change modeling. A cloud droplet formation parameterization was developed to i) predict droplet formation from a lognormal representation of aerosol size distribution and composition, and, ii) include a size-dependant mass transfer coefficient for the growth of water droplets which explicitly accounts for the impact of organics on droplet growth kinetics. The parameterization unravels most of the physics of droplet formation and is in remarkable agreement with detailed numerical parcel model simulations, even for low values of the accommodation coefficient. The parameterization offers a much needed rigorous and computationally inexpensive framework for directly linking complex chemical effects on aerosol activation in global climate models. The new aerosol activation parameterization was also tested against observations from highly polluted clouds (within the vicinity of power plant plumes). Remarkable closure was achieved (much less than the 20% measurement uncertainty). The error in predicted cloud droplet concentration was mostly sensitive to updraft velocity. Optimal closure is obtained if the water vapor uptake coefficient is equal to 0.06. These findings can serve as much needed constraints in modeling of aerosol-cloud interactions in the North America. Aerosol water interactions in ambient relative humidities less than 100% were studied using a thermodynamic equilibrium model for inorganic aerosol and a three dimensional air quality model. We developed a new thermodynamic equilibrium model, ISORROPIA-II, which predicts the partitioning of semi-volatiles and the phase state of K+/Ca2+/Mg2+/NH4+/Na+/SO42-/NO3-/Cl-/H2O aerosols. A comprehensive evaluation of its performance was conducted against the thermodynamic module SCAPE2 over a wide range of atmospherically relevant conditions. Based on its computational rigor and performance, ISORROPIA-II appears to be a highly attractive alternative for use in large scale air quality and atmospheric transport models. The new equilibrium model was also used to thermodynamically characterize aerosols measured at a highly polluted area. In the ammonia-rich environment of Mexico City, nitrate and chloride primarily partition in the aerosol phase with a 20-min equilibrium timescale; PM2.5 is insensitive to changes in ammonia but is to acidic semivolatile species. When RH is below 50%, predictions improve substantially if the aerosol follows a deliquescent behavior. The impact of including crustal species (Ca2+, K+, M2+) in equilibrium calculations within a three dimensional air quality model was also studied. A significant change in aerosol water (-19.8%) and ammonium (-27.5%) concentrations was predicted when crustals are explicitly included in the calculations even though they contributed, on average, only a few percent of the total PM2.5 mass, highlighting the need for comprehensive thermodynamic calculations in the presence of dust.

Thesis (M. Tech. (Agriculture)) -- Central University of Technology, Free state, 2011
Quality assessment of agricultural water used for fertigation in the Boland district. The study was undertaken to determine the influence of seasonal changes on the water quality (chemical and microbial analyses) of five different rivers in the Boland. The data was collected in the five most important water sources that are used for irrigation purposes in the district, i.e. Berg river, Eerste river, Klapmuts River, Klippies river and Krom river. The samples were collected from all sites once every three weeks for a period of six months. The sampling was carried out during specific periods in summer (December, 2006 to February, 2007) and winter (June to August, 2007). The results of the study showed that Klapmuts river recorded the highest levels of chloride and iron, especially in summer. However, chloride levels were far below the levels set by the Department of Water Affairs and Forestry. Results obtained from this study show the presence of pathogens in some of the rivers assessed which may have resulted from the leaching of these pathogens from nearby agricultural land, livestock watering or informal settlements in the catchment areas. The bigger rivers recorded low levels of micro-elements and this might have been affected by winter rainfall. In the Berg River, many sources of nitrate pollution seem to be present in the catchment area. The levels of iron in all the rivers assessed were far more than the levels set by the Department of Water Affairs and Forestry in all rivers assessed and these might be due to the pH levels and interaction between the rivers and seasons. Iron and manganese levels should be kept low as this may cause production problems by blocking irrigation drippers. The water samples tested for bacterial and fungal density showed Klapmuts and Eerste rivers were positive for Phytophthora cinnamomi during winter. Phytophthora citricola and Phytophthora cactorum were detected in the Klapmuts and Klippies rivers in summer. The Berg-, Klapmuts-, Krom- and Eerste rivers tested positive for species of the genera Pythium and Fusarium. Similar organisms were detected in the Eerste river mainly during summer on the fourth sampling date, while Krom river only tested positive for Pythium during summer. The total bacterial and algal density differed significantly between the seasons and was highest in winter. This might be due to high rain water influx and efflux and/or moist and aerobic conditions and air temperature. There is an increased need for farmers to sterilize feeding water (chlorination) due to high microbial count.

Thesis (M. Tech. (Agriculture)) -- Central University of Technology, Free state, 2014
The main objective of the study was to determine the effect of different potassium concentrations and water quality (salt) compared with the current scientifically accepted potassium threshold level and standardised water quality on the yield, oil composition and leaf morphology of rose geranium (Pelargonium graveolens L.) when grown in different potting-bag sizes and root media under temperature controlled condition. To achieve this objective, two trials were conducted. The first experiment evaluated potassium concentrations at 1.3, 3.3, 5.3 and 7.3 mmol L-1 and potting-bag size of 5 and 10 L. Treatments were arranged in a randomised complete block design assigned in a split plot layout. The main plots consisted of potassium concentration and the pottingbag sizes were allocated to sub-plots. Plant height, potassium content, linalool, geraniol, geranyl formate and the citronellol to geraniol ratio (C:G) were affected by potassium. Plant height, number of branches, the branch to height ratio (B:H), foliar fresh mass (FFM) and oil yield were significantly increased when 5 L potting bags were used. Plant foliar mass was significantly increased by the interaction between 5.3 mmol K L-1 and 5 L potting bags. In the second experiment salt levels applied at 1.6, 2.4, 3.2 and 4.0 mS cm-1 and root media (sand and sawdust) were evaluated. A split plot experimental layout was also used in this trial, with the salt levels allocated to the main plots. The sub-plots were allocated to the root medium. High salt level of 4.0 mS cm-1 reduced the number of leaves, plant height, number of branches, B:H ratio, leaf area, chlorophyll content and foliar fresh mass significantly. The number of leaves, leaf area and FFM were significantly increased where sawdust was used. Time of the day significantly affected stomatal conductance, and the opening of most stomata occurred at 10:00. Geranyl formate and the C:G ratio were significantly affected by salt at 4.0 mS cm-1. Salt induced the development of capitates trichomes. The abaxial leaf surface had a higher number of trichomes than the adaxial leaf surface. A strong polynomial (r2=0.97) relationship was found between capitates trichomes and salt levels. High densities of capitates trichomes were found at high salt level of 4.0 mS cm-1. Although the development of asciiform trichomes was induced, it was at an insignificant level. Trichome densities are therefore not affected by salt. It was therefore concluded that the application of 5.3 mmol K L-1 concentration and the use of 5 L potting bags improves the yield and oil quality of rose geranium. It was evident from this study that rose geranium might Salt induced have some degree of tolerance to salt. It was therefore concluded that rose geranium is a moderately salt-sensitive crop.

The European Water Framework Directive 2000 established a new emphasis for the management of freshwaters by setting ecologically-based water quality targets that are to be achieved through holistic, catchment-scale, ecosystem management. However, significant knowledge gaps exist in the understanding of the cumulative effectiveness of multiple mitigation measures on a number of pollutants at a catchment scale. This research contributes to improved understanding of the effectiveness of an ecosystem management approach to deliver catchment-scale water quality improvements on the National Trust Holnicote Estate on Exmoor, UK. This research is part of a larger multi-objective project funded by the UK Department for Environment, Food and Rural Affairs (Defra), to demonstrate the benefits of land use interventions for the management of flood risk. This thesis evaluates the effects of upland ditch blocking on physico-chemical and biological parameters of water quality in an upland Horner Water catchment one year after habitat restoration, and establishes a solid baseline for the monitoring of the effects of current and future land management changes in a lowland, intensively managed, agricultural Aller catchment. The spatial variability of soil physical and chemical properties (bulk density, total carbon (TN), nitrogen (TN), C:N ratio, δ15N, total phosphorus (TP), inorganic phosphorus (IP), organic phosphorus (OP)) and water quality determinands (suspended sediment (SS), dissolved organic carbon (DOC), total particulate carbon (TPC), total oxidised nitrogen (TON) and dissolved reactive phosphorus (DRP)) in the two study catchments with contrasting land use has been characterised and linked to the prevailing land use. Agricultural land use resulted in extensive homogenisation of soil properties. The spatial dependence of all soil properties, except for bulk density and δ15N, was stronger in the agricultural than the semi-natural catchment (nugget:sill ratio 0.10-0.42 in the Aller and 0.15-0.94 in Horner Water), while bulk density, TP, inorganic phosphorus (IP), organic phosphorus (OP), C:N ratio, δ15N and carbon storage showed a longer range of spatial auto-correlation in the agricultural catchment (2,807-3,191 m in the Aller and 545-2,599 m Horner Water). The central tendency (mean, median) of all soil properties, except for IP and δ15N, also differed significantly between the two catchments (P < 0.01). The observed extensive alteration of soil physical and chemical properties in the agricultural catchment is likely to have long-term implications for the restoration of ecosystem functioning and water quality management. The intensive land use seems to have resulted in an altered ‘catchment metabolism’, manifested in a proportionally greater total fluvial carbon (dissolved and particulate) export from the agricultural than the semi-natural catchment. The agricultural catchment supported significantly higher DOC concentrations (P < 0.05) and the quality of DOC differed markedly between the two study catchments. The prevalence of more humic, higher molecular weight compounds in the agricultural catchment and simpler, lower molecular weight compounds in the semi-natural catchment, indicated enhanced microbial turnover of fluvial DOC in the agricultural catchment as well as additional allochtonous terrestrial sources. During an eight month period for which a comparable continuous turbidity record was available, the estimated SS yields from the agricultural catchment (25.5-116.2 t km2) were higher than from the semi-natural catchment (21.7-57.8 t km2). Further, the agricultural catchment exported proportionally more TPC (0.51-2.59 kg mm-1) than the semi-natural catchment (0.36-0.97 kg mm-1) and a similar amount of DOC (0.26-0.52 kg mm-1 in the Aller and 0.24-0.32 kg mm-1 in Horner Water), when normalised by catchment area and total discharge, despite the lower total soil carbon pool, thus indicating an enhanced fluvial loss of sediment and carbon from the intensively managed catchment. Whilst detection of catchment-scale effects of mitigation measures typically requires high resolution, resource-intensive, long term data sets, this research has found that simple approaches can be effective in bridging the gap between fine scale ecosystem functioning and catchment-scale processes. Here, the new macro-invertebrate index PSI (Proportion of Sediment-sensitive Invertebrates) has been shown to be more closely related to a physical measure of sedimentation (% fine bed sediment cover) (P = 0.002) than existing non-pressure specific macro-invertebrate metrics such as the Lotic Index for Flow Evaluation (LIFE) and % Ephemeroptera, Plecoptera & Trichoptera abundance (% EPT) (P = 0.014). Further testing of PSI along a pronounced environmental gradient is recommended as PSI and % fine bed sediment cover have the potential to become a sensitive tool for the setting and monitoring of twin sedimentation targets. Upland ditch management has not had any discernible effect on water quality in the semi-natural upland catchment one year after restoration, which may be due to the short-term post-restoration monitoring period but may also reflect benign effects of large-scale earth moving works on this high quality environment. The conceptual understanding of catchment processes developed in this thesis suggests that cumulatively, the recently completed mitigation works in the lowland agricultural catchment will likely result in reduced sediment and nutrient input into the aquatic environment. However, further research is needed to build on this detailed baseline characterisation and inform the understanding of the effectiveness of combined mitigation measures to reduce the flux of multiple contaminants at the catchment scale.

The passage of the Federal Water Pollution Control Act of 1972 required states to develop forestry BMPs to help reduce potential nonpoint source pollution from forest operations. Properly applied forestry best management practices (BMPs) have since been proven to protect water quality from forest operations. This research project reviewed BMP effectiveness studies in the U.S., assessed current state developed and implemented of forestry BMPs, and developed a simple method to estimate potential erosion from forest operations for the Piedmont physiographic region based on previous studies. Eighty-one BMP effectiveness studies were reviewed. The review of past effectiveness studies indicates that water quality protection is increased when BMPs are implemented correctly. These effectiveness studies provide states with valuable information on how their BMP guidelines are achieving the goals defined by the Federal Water Pollution Control Act. Every U.S. state has forestry BMP guidelines. These guidelines may be non-regulatory, quasi-regulatory, or regulatory depending on the state. Twenty states reported implementing non-regulatory BMP guidelines, 19 quasi-regulatory BMP guidelines, and 11 regulatory BMP guidelines. State forestry agencies were reported as being the lead agency responsible for BMP monitoring in 35 states. The national forestry BMP implementation rate was 91% (32 states). However, states did report deficiencies for specific BMP guideline categories. Supplementary to the reviewed BMP effectiveness studies, forest erosion studies in the southeastern U.S. that quantified erosion rates from forest operations were also reviewed. Erosion rates obtained from the literature were reviewed by operation categories (timber harvesting, forest roads, skid trails, log landings, stream crossings, and streamside management zones) and physiographic region (Mountains, Piedmont, Gulf Coastal Plain, and Atlantic Coastal Plain). There were numerous research gaps regarding erosion rates from forest operations for all the regions except the Piedmont region. The Piedmont region was selected for developing a method to estimate potential erosion from forest operations. This erosion estimation method is a quick and potentially useful tool for estimating potential erosion; however, it is based on limited data from the Piedmont region only. The basic method approach might be considered for the other physiographic regions, but further research is needed to fill current knowledge gaps.
Ph. D.

Grand Coulee Dam created Franklin D. Roosevelt Lake as part of the Columbia Basin Project. Located in northeastern Washington State, the Project provides economically important hydropower (19 billion kilowatt hours per year), irrigation (225,000 ha), flood control, and sport fishing ($5 to 20 million annually). A good system understanding aids in balancing these beneficial uses for the 230 km long reservoir. The reservoir's atypical 45-day mean residence time is much shorter than a typical lake, and much longer than for a riverine dam. The spring freshet requires drawdowns of 15 to 20 m for flood control—the driving characteristic of reservoir operations. A physically based two-dimensional hydrodynamic and water quality model, CE-QUAL-W2 Version 3.5 (Cole and Wells, 2006), is coupled with a fish bioenergetics model based on the Stockwell and Johnson model (1997, 1999) to examine the effects of hydrodynamics on the reservoir algae-zooplankton-kokanee food web. This model was applied and calibrated to Lake Roosevelt with model improvements of multiple zooplankton compartments and zooplankton omnivory. Calibration parameters included temperature, dissolved oxygen, nutrients, algae, and zooplankton. The fish bioenergetics model is applied over the entire reservoir model space to generate a spatial and temporal fish growth potential distribution. The fish model refinements include sub-daily time-steps and an optimized vertical foraging strategy. The linked model suggests that kokanee fish growth potential is seasonally limited by both warm water and prey densities. While the lake ecology is significantly affected by the reservoir operations in general, the pelagic fish growth potential did not appear sensitive to minor changes in reservoir operations. However, the model suggests that the advantageous foraging locations shift seasonally and that optimal foraging strategies are dependent on fish size.

The EU's Water Framework Directive aims to a long-term and sustainable use of our water resources and wants to ensure good water quality in Europe's water bodies. Discharge of polluted stormwater into receiving waters can be a threat to their ecological and chemical status. Municipalities are responsible for supervision of the environmental quality standards (EQS) and therefore need to gain knowledge of current stormwater management, the expected level of pollution emissions and possible appropriate purification steps to ensure that the goal of good water quality is achieved. This master thesis aims to provide this knowledge in the example case of Vallentunas urban area and wants to prepare future oversight so that it can be assessed how much the discharge of polluted stormwater into the local receiving water is a threat to its status. With the help of maps, aerial photographs, site observations and individual discussions those areas are mapped where appearance of moderate to highly polluted stormwater could be suspected. The degree of pollution at the discharge points is determined based on land use upstream and uses standard values according to the administrators assistance "Tillsyn av dagvatten" (MSL 2014). The study identifies 100 areas in need of supervision regarding their stormwater management. The information is digitized and made available to all affected departments in the municipality via the internal GIS. Through literature review this thesis highlights even the legal provisions for the supervision and its importance to the environmental quality standards and also consider the importance of the expected climate change for the stormwater pollution. The work emphasizes the importance of increased information flow and communication between the different actors that are significant for surface water management and environmental quality standards for water. For being able to look at the examination area from an international perspective the essay does a simpler comparison of the municipal supervision of stormwater management between Sweden and the state of Schleswig Holstein in Germany.
EU:s ramdirektiv för vatten syftar till ett långsiktigt och hållbart utnyttjande av våra vattenresurser och ska säkra en god vattenkvalitet i Europas vattenförekomster. Utsläpp av förorenat dagvatten till recipienterna kan vara ett hot för deras ekologiska och kemiska status. Kommunerna har tillsynsansvar för miljökvalitetsnormerna (MKN) och därför behov att få kunskap om nuvarande dagvattenhantering, förväntad föroreningsgrad av utsläppen och eventuella lämpliga reningsåtgärder för att säkerställa att målet med en god vattenkvalitet uppnås. Arbetets syfte är att hjälpa till att skaffa denna kunskap i exempelfallet Vallentuna tätort och förbereda framtida tillsyn så att det kan göras en bedömning av hur pass mycket utsläppet av förorenat dagvatten till den lokala recipienten är ett hot för dess status. Med hjälp av kartor, flygbilder, platsobservationer och enskilda samtal kartläggs områden där man kan förvänta sig uppkomsten av måttligt till starkt förorenat dagvatten. Föroreningsgraden vid utsläppspunkterna bestäms utifrån markanvändning uppströms och använder schablonvärden enligt handläggarstödet "Tillsyn av dagvatten" (MSL 2014). Undersökningen pekar ut 100 områden som har behov av tillsyn rörande deras dagvattenhantering. Informationen digitaliseras och görs tillgänglig för alla berörda enheter i kommunen via det interna GIS-systemet. Genom granskning av litteraturen belyses bl.a. även de rättsliga bestämmelserna för tillsynen och dess betydelse för miljökvalitetsnormerna samt att det tas hänsyn till förväntad klimatförändring. Arbetet betonar vikten av ett ökat informationsflöde och kommunikation mellan de olika aktörerna som har betydelse för dagvattenhanteringen och miljökvalitetsnormerna för vatten. För att se på uppsatsens undersökningsområde ur ett internationellt perspektiv görs även en enklare jämförelse av tillsynen för dagvattenhanteringen mellan Sverige och förbundslandet Schleswig Holstein i Tyskland.

Mestrado em Microbiologia
Freshwater ecosystems have been suffering severe degradation and loss of biodiversity, caused by human disturbances such as agriculture, industry, mining, urban development and climate changes. Therefore, the European Union reached an agreement and implemented the Water Framework Directive (WFD), with the main goal of reach a good ecological status in all water bodies. However, WFD is very complex, methodologies are time-consuming and costly. Thus, the main objective of this study is to develop a rapid and cost-effective approach, by studying the bacterial community composition by flow cytometry, as a complementary methodology to WFD. To achieve this, we study 3 sampling sites at Caima River along the seasons (winter, spring and summer), with different levels of environmental impacts (Nascente- river source- with little impact, Bustelo- downstream WWTP and Palhal- exposed to mine drainage), applying first the WFD criteria and then multivariate analysis for macroinvertebrate, periphyton and bacteria communities. Physico-chemical, metals and bacteria samples were collected from the water column and sediment river bottom, showing that in all the parameters (with some exceptions) and metals the concentrations were higher in sediments. Results showed that not always the macroinvertebrate and periphyton communities were sensitive to an increased nutrient input, resulting in an ecological status higher than expected. On the other hand, community structure analysis for macroinvertebrates and periphyton was very discriminatory, associating high levels of nutrients and metals with more tolerant organisms in impacted sites, and sensitive organisms with high levels of dissolved oxygen corresponding to pristine environments. Bacteria community analysis revealed a clear separation of LNA and HNA bacteria in sediment according to the different environmental stress, being possible to dissociate the majority of the impacted sites from the clean sites, being HNA a good indicator of contamination. These results revealed that bacteria community in sediments has more reliable data about the impacts that a freshwater ecosystem can suffer. The discriminating power of bacteria community analyzed by FCM provided good responses, although, further investigations are needed to confirm the feasibility of this new method, as a complementary tool in the water quality assessment.
Os sistemas aquáticos de água doce têm vindo a sofrer uma severa degradação e perda de biodiversidade, derivado de atividades humanas como a agricultura, indústria, atividades mineiras desenvolvimento urbano e alterações climáticas. Assim, a União Europeia implementou a Diretiva Quadro da Água (DQA), com o principal objetivo de atingir o bom estado ecológico em todas as massas de água. No entanto, a DQA revelou ser bastante complexa, com metodologias muito morosas e dispendiosas. Com este estudo, pretende-se desenvolver uma metodologia rápida e económica, estudando a composição da comunidade bacteriana por citometria de fluxo, como ferramenta complementar à DQA. Para a concretização deste trabalho, foram estudados 3 locais do rio Caima com diferentes tipos de impactos: a nascente – local de referência; Bustelo - a jusante de uma estação de tratamento de águas residuais e o Palhal - com escorrências provenientes de uma mina desativada, no inverno, primavera e verão aplicando a metodologia estabelecidas pela DQA usando os macroinvertebrados e perifiton como comunidades biológicas estudadas. Adicionalmente foi aplicada a análise multivariada aos dados recolhidos por citometria de fluxo à comunidade de bactérias da coluna de água e dos elutriados dos sedimentos e aos resultados das comunidades de macroinvertebrados e perifiton obtidos da DQA. No geral, os parâmetros físico-químicos, e as quantificações de metais mostraram valores mais elevados nos elutriados dos sedimentos do rio, do que na coluna de água mostrando a importância da análise desta matriz que não está contemplada na DQA. Resultados sensu DQA mostraram que nem sempre as comunidades de macroinvertebrados e perifiton foram concordantes na resposta aos diferentes tipos de impactos e que a qualidade ecológica dos locais avaliados foi melhor do que era expectável. Por outro lado, a análise multivariada das comunidades de macroinvertebrados e perifiton foi bastante discriminatória, associando elevados níveis de nutrientes e metais com organismos mais tolerantes, que se encontram em locais mais impactados, e organismos sensíveis com altos níveis de oxigénio dissolvido em locais mais pristinos. A análise da comunidade bacteriana revelou uma distinta separação entre bactérias LNA e HNA nos sedimentos, de acordo com os diferentes stresses ambientais, sendo HNA, nos sedimentos, um ótimo indicador de contaminação. Estes resultados revelam que a comunidade bacteriana oferece uma boa resolução de locais contaminados usando a citometria de fluxo como metodologia rápida de avaliação complementar à avaliação do estado ecológico sensu DQA sendo, no entanto, necessárias mais estudos aplicados a outras tipologias de rios e outros tipos de impactos para confirmar a validade desta nova metodologia.

Changes in trophic status are often related to increases or decreases in the allocthonous inputs of nutrients from changes in land use and management practices. Lake and reservoir managers are continually faced with the questions of what to monitor, how to monitor it, and how much change is necessary to be considered significant. This study is a compilation of four manuscripts, addressing one of these questions, using data from six reservoirs in Texas.

>Magister Scientiae - MSc
Wetlands are unique ecosystems that are acknowledged among the world’s most productive and valuable ecosystems. They are recognized as being essential to sustainable development and human welfare due to their unique environmental and socio-economic value. These highly productive ecosystems provide functions such as recycling of nutrients, watershed protection and flood control as well as grazing resources. Wetlands provide the basis for human livelihoods in Africa through ecosystem services. However, these ecosystems are affected by internal and external factors within and outside their catchments, hence the importance of monitoring those changes around these wetlands.