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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Evaluation Of Toxic Cyanobacteria In Central Florida Stormwater Ponds

Miller, Robert 01 January 2005 (has links)
Algal blooms are a common occurrence in water bodies of all shapes and sizes throughout the United States and countries around the world. The State of Florida is no exception to this phenomenon. Cyanobacteria, or blue-green algae, have proven to be of special concern due to its proliferation and potential to produce toxins that are harmful to humans, livestock and wildlife. A casual drive along the roads and in the neighborhoods of central Florida will confirm algal conditions in many areas. The potential for exposure to harmful and possibly fatal toxins associated with these algal blooms are becoming more evident as urban development progresses. Detailed studies have been previously performed for large lakes and rivers in the State of Florida, but no studies have been performed regarding stormwater ponds. Since stormwater ponds in residential neighborhoods are a common source for irrigation, research in this area is warranted due to the potential health effects associated with Cyanobacteria. This research was conducted to determine if Cyanobacteria does exist in stormwater ponds and to what extent. Cyanobacteria were found to be in stormwater ponds of various sizes, locations and watersheds in the central Florida area. Even though the algae and its associated toxins were encountered in the stormwater ponds evaluated for this study, the levels detected were much lower than the values discovered in previous studies performed in the larger lakes and rivers around the State.
12

Determinação de cianotoxinas em amostras de florações de cianobactérias coletadas em pesque-pagues e pisciculturas situadas na região do Alto Mogi / Determination of cyanotoxins in samples of blooms of cyanobacteria collected in fish farming located in the region of Alto Mogi.

Andrade, Fabiana Martins de 21 August 2009 (has links)
O crescimento acelerado da aqüicultura no estado de São Paulo, ou seja, a implantação de pesque-pagues e pisciculturas pode estar causando uma série de problemas ambientais. A contribuição para o processo de eutrofização é uma das conseqüências desses empreendimentos, pois tanto os tanques utilizados na piscicultura como os afluentes em torno desses estabelecimentos, estão sendo eutrofizados pelo excesso de nutrientes. Uma das conseqüências da eutrofização é o aparecimento de florações de cianobactérias, e a principal preocupação está nas toxinas liberadas por estas cianobactérias, que se ingeridas pelos seres humanos e animais, podem causar efeitos de intoxicação, como fraqueza, cefaléia, vômito e dependendo da concentração ingerida pode levar à morte. Desta forma é necessário que haja um programa de controle da qualidade da água dos tanques e reservatórios e também dos peixes que ali são criados, pois florações de cianobactérias vêm sendo encontradas em diversos corpos d\'água. Este estudo teve como foco a determinação da cianotoxina microcistina-LR, empregando técnicas como a extração em fase sólida e a cromatografia líquida para a detecção e quantificação da microcistina-LR em amostras de florações de cianobactérias. Os testes feitos com a extração em fase sólida demonstraram que esse procedimento não se faz necessário para todas as amostras, pois houve casos em que não se obteve diferença nos picos interferentes mais próximos ao tempo de retenção do analito de estudo. Como as matrizes desse tipo de amostras são muito complexas e variam muito conforme o meio em que se encontram, recomenda-se que sejam avaliados caso à caso a necessidade de se promover a extração em fase sólida, pois o mesmo é um processo que demanda um tempo maior de análise e conseqüente aumento nos custos. Foi determinado e validado um método cromatográfico considerado capaz de fornecer dados reproduzíveis e confiáveis, por meio de testes de seletividade, limite de detecção e de quantificação, linearidade, precisão, exatidão e recuperação, conforme critérios de aceitação da Resolução n°899 de 2003, da ANVISA. O limite de detecção do método ficou estipulado em 0,1 µg mL-1, e o limite inferior de quantificação em 0,5 µg mL-1, determinados conforme a relação sinal-ruído proposta pelo Guia de Validação de Métodos Bioanalíticos da ANVISA. A quantificação da microcistina-LR foi feita utilizando o método de superposição de matriz, que minimiza e/ou compensa o efeito de matriz ou de possíveis interferentes presentes na amostra, e a curva analítica obtida y = 1,5888+21,849 x, com um coeficiente de correlação de 0,997 mostra uma boa linearidade. Foram analisadas amostras de florações de cianobactérias, coletadas em pesque-pagues e pisciculturas situadas na região do Alto Mogi (subdivisão da bacia do Mogi Guaçu), conforme o método de extração e análise estudado. / The rapid growth of aquaculture in the state of São Paulo may be causing a number of environmental problems. The contribution to the eutrophication process is among the consequences of these undertakings, given that the tanks used in fish farming as well as the changes around these establishments are becoming eutrophic systems due to excessive nutrients. A frequent consequence of eutrophication in waters is the massive development of cyanobacteria.The occurrence of these blooms induces severe problems, as Microcystis aeruginosa, the most widespread distributed cyanobacteria, which can produce microcystin-LR. Toxic effects of MC have been described in liver, lungs, stomach, and intestine. Deaths in wildlife, livestock and human beings were also associated with microcystin exposition, which can occur directly by ingestion, inhalation, contact, intravenous inoculation of contaminated water (hemodialysis) or indirectly, by the consumption of animals, as fish and mollusks, the major ingestors of cyanobacteria and its toxins. Thus we need a program to control the quality of water tanks and reservoirs and also the fish breeded there, as cyanobacteria blooms have been found in various water bodies. This study focused on the determination of the cyanotoxins microcystin-LR, using techniques such as solid phase extraction and liquid chromatography for the detection and quantification of microcystin-LR in samples of cyanobacteria blooms. Tests performed with solid phase extraction showed that this procedure is not necessary for all the samples because there were cases where no difference was obtained in interfering peaks near the retention time of the analyte studied. As the parent of such samples are very complex and vary greatly, because the extracts contained too much coextrated material that interfered in the LC-UV detection, and depending on the way in which it is recommended to be assessed, case by case, the solid phase extraction needs to be promoted, because it is a process that demands a longer period of analysis and consequently an increase in costs. A liquid chromatography method was established and validated, which is deemed capable of providing reproducible and reliable data, by testing for selectivity, limit of detection and quantification, linearity, precision, accuracy and recovery, in accordance with the acceptance criteria of Resolution No. 899 of 2003 of ANVISA. The detection limit of the method was set at 0.1 µg mL-1, and the lower limit of quantification at 0.5 µg mL-1 determined according to the signal to noise ratio proposed by the Validation Guide of Bioanalytical Methods, ANVISA. Quantification of microcystin-LR was performed using the matrix-matched method, which minimizes and/or offsets the effect of possible matrix interference or present in the sample. The analytical curve obtained y = 1.5888 + 21.849 x, with a coefficient of correlation of 0.997 shows a good linearity. Real aquaculture samples were analyzed that were detected and quantified according to the method developed.
13

Effects of Electromagnetic Hydrolysis on Dissolved Oxygen in Small Ponds

Unknown Date (has links)
This pilot study was conducted to determine if an Electron Magnetics Oxygen and Hydrogen (EMOH) device can increase the dissolved oxygen (DO) concentration of a residential surface water. By using EMOH, DO concentration will increase and allow bacteria to remove the substrate that creates blue-green algae for which the City of Boynton Beach (City) receives complaints. Those complaints center on odors and the visual appearance of the ponds. The study was conducted in-situ at the INCA Pond system in the City of Boynton Beach, Florida with data collection taking place bi-weekly, using surface aeration techniques. Water sampling was conducted in the INCA Pond system via a handheld water sensor. Primary variable monitored included: water temperature, barometric pressure, DO concentration, and DO saturation (DOSAT). Biomass of dead algae at the bottom of the pond was also monitored to determine if increased DO concentration aided the biological digestion of the organic matter. Data analysis shows that exposure to EMOH treatment allowed the relationship between DO and temperature to change from a negative correlation (the expected relationship) to a positive trend. Furthermore, pressure and DOSAT became less correlated after exposure to EMOH effluent. In all, EMOH was shown to be an effective means of treating hypoxic pond water. The optimal EMOH effluent discharge is determined to be deep in the subject pond. Backed by research on the surface-air water and bubble-water oxygen transfer coefficients, DO concentration in the subject pond was 110% higher when effluent was directed down toward the floor of the pond. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection
14

DEVELOPMENT OF ANALYTICAL METHODS AND REFERENCE MATERIALS FOR CYANOBACTERIAL TOXINS

Hollingdale, Christie 16 May 2013 (has links)
Cyanobacterial toxins present a real and growing threat to humans and animals due to the projected increases in algal blooms resulting from increasing global temperature and pollution. Wild animals, livestock, pet animals and humans can be poisoned from contaminated drinking water. With the discovery of cyanobacterial toxins present in nutritional supplements, a new concern looms over consumers with threats of neurotoxin and hepatotoxin related damage from exposure to these products. To this end, work on the development of a freeze dried algal reference material was pursued for future use in environmental and nutritional supplement analysis. The first stage of the project was to prepare needed calibration standards, starting with homoanatoxin a, a homologue of the highly neurotoxic anatoxin-a compound. The resulting reference material (RM-hATX) had a homoanatoxin-a concentration of 20.2 ± 0.7 ?M, and proved to be stable while stored at temperatures of 80°C. Reference samples for dihydro and epoxy analogues of anatoxin-a and homoanatoxin-a were then prepared by semi-synthesis. The second stage of the project was the development of new analytical methods for the anatoxins. A derivatization reaction in which dansyl chloride was coupled with a novel cleanup step produced anatoxin derivatives suitable for liquid chromatography (LC) with mass spectrometry (MS) or fluorescence detection (FLD). Limits of quantitation were 60 ng L-1 and 1.6 ?g L-1 for the developed LC-MS/MS and LC-FLD methods, respectively, with the limit of quantitation significantly better than that of a previously developed method for the underivatized toxins based on HILIC MS/MS. Quantitative results for anatoxins in various algal samples using all three methods of analysis of were compared and it was found that there were no significant differences between the three methods. Unfortunately, experiments showed that the various toxin analogues did not elicit equimolar responses in either LC-MS/MS or LC FLD, thus indicating the importance of having individual calibration standards for quantitative analysis. The LC-MS/MS and LC-FLD methods were paired with a previously developed method for the analysis of hepatotoxic microcystins to screen a small number of nutritional supplement samples for cyanobacterial toxins. Microcystins were detected in all five Aphanizomenon flos-aquae samples examined. This method involved a fifteen-fold pre-concentration using a solid phase extraction cartridge, which gave a 98% recovery of microcystins. The third phase of the project was the preparation and testing of a preliminary algal matrix reference material as a feasibility study for the eventual production of a CRM. After selecting various algal cultures and samples that could be blended together, a freeze dried algal reference material was prepared and packaged. This material (RM-BGA) was then characterized using several methods including the two new dansylation-based procedures.
15

Determinação de cianotoxinas em amostras de florações de cianobactérias coletadas em pesque-pagues e pisciculturas situadas na região do Alto Mogi / Determination of cyanotoxins in samples of blooms of cyanobacteria collected in fish farming located in the region of Alto Mogi.

Fabiana Martins de Andrade 21 August 2009 (has links)
O crescimento acelerado da aqüicultura no estado de São Paulo, ou seja, a implantação de pesque-pagues e pisciculturas pode estar causando uma série de problemas ambientais. A contribuição para o processo de eutrofização é uma das conseqüências desses empreendimentos, pois tanto os tanques utilizados na piscicultura como os afluentes em torno desses estabelecimentos, estão sendo eutrofizados pelo excesso de nutrientes. Uma das conseqüências da eutrofização é o aparecimento de florações de cianobactérias, e a principal preocupação está nas toxinas liberadas por estas cianobactérias, que se ingeridas pelos seres humanos e animais, podem causar efeitos de intoxicação, como fraqueza, cefaléia, vômito e dependendo da concentração ingerida pode levar à morte. Desta forma é necessário que haja um programa de controle da qualidade da água dos tanques e reservatórios e também dos peixes que ali são criados, pois florações de cianobactérias vêm sendo encontradas em diversos corpos d\'água. Este estudo teve como foco a determinação da cianotoxina microcistina-LR, empregando técnicas como a extração em fase sólida e a cromatografia líquida para a detecção e quantificação da microcistina-LR em amostras de florações de cianobactérias. Os testes feitos com a extração em fase sólida demonstraram que esse procedimento não se faz necessário para todas as amostras, pois houve casos em que não se obteve diferença nos picos interferentes mais próximos ao tempo de retenção do analito de estudo. Como as matrizes desse tipo de amostras são muito complexas e variam muito conforme o meio em que se encontram, recomenda-se que sejam avaliados caso à caso a necessidade de se promover a extração em fase sólida, pois o mesmo é um processo que demanda um tempo maior de análise e conseqüente aumento nos custos. Foi determinado e validado um método cromatográfico considerado capaz de fornecer dados reproduzíveis e confiáveis, por meio de testes de seletividade, limite de detecção e de quantificação, linearidade, precisão, exatidão e recuperação, conforme critérios de aceitação da Resolução n°899 de 2003, da ANVISA. O limite de detecção do método ficou estipulado em 0,1 µg mL-1, e o limite inferior de quantificação em 0,5 µg mL-1, determinados conforme a relação sinal-ruído proposta pelo Guia de Validação de Métodos Bioanalíticos da ANVISA. A quantificação da microcistina-LR foi feita utilizando o método de superposição de matriz, que minimiza e/ou compensa o efeito de matriz ou de possíveis interferentes presentes na amostra, e a curva analítica obtida y = 1,5888+21,849 x, com um coeficiente de correlação de 0,997 mostra uma boa linearidade. Foram analisadas amostras de florações de cianobactérias, coletadas em pesque-pagues e pisciculturas situadas na região do Alto Mogi (subdivisão da bacia do Mogi Guaçu), conforme o método de extração e análise estudado. / The rapid growth of aquaculture in the state of São Paulo may be causing a number of environmental problems. The contribution to the eutrophication process is among the consequences of these undertakings, given that the tanks used in fish farming as well as the changes around these establishments are becoming eutrophic systems due to excessive nutrients. A frequent consequence of eutrophication in waters is the massive development of cyanobacteria.The occurrence of these blooms induces severe problems, as Microcystis aeruginosa, the most widespread distributed cyanobacteria, which can produce microcystin-LR. Toxic effects of MC have been described in liver, lungs, stomach, and intestine. Deaths in wildlife, livestock and human beings were also associated with microcystin exposition, which can occur directly by ingestion, inhalation, contact, intravenous inoculation of contaminated water (hemodialysis) or indirectly, by the consumption of animals, as fish and mollusks, the major ingestors of cyanobacteria and its toxins. Thus we need a program to control the quality of water tanks and reservoirs and also the fish breeded there, as cyanobacteria blooms have been found in various water bodies. This study focused on the determination of the cyanotoxins microcystin-LR, using techniques such as solid phase extraction and liquid chromatography for the detection and quantification of microcystin-LR in samples of cyanobacteria blooms. Tests performed with solid phase extraction showed that this procedure is not necessary for all the samples because there were cases where no difference was obtained in interfering peaks near the retention time of the analyte studied. As the parent of such samples are very complex and vary greatly, because the extracts contained too much coextrated material that interfered in the LC-UV detection, and depending on the way in which it is recommended to be assessed, case by case, the solid phase extraction needs to be promoted, because it is a process that demands a longer period of analysis and consequently an increase in costs. A liquid chromatography method was established and validated, which is deemed capable of providing reproducible and reliable data, by testing for selectivity, limit of detection and quantification, linearity, precision, accuracy and recovery, in accordance with the acceptance criteria of Resolution No. 899 of 2003 of ANVISA. The detection limit of the method was set at 0.1 µg mL-1, and the lower limit of quantification at 0.5 µg mL-1 determined according to the signal to noise ratio proposed by the Validation Guide of Bioanalytical Methods, ANVISA. Quantification of microcystin-LR was performed using the matrix-matched method, which minimizes and/or offsets the effect of possible matrix interference or present in the sample. The analytical curve obtained y = 1.5888 + 21.849 x, with a coefficient of correlation of 0.997 shows a good linearity. Real aquaculture samples were analyzed that were detected and quantified according to the method developed.
16

Quantification of Microcystis in the Waters of Western Lake Erie and the Maumee River in the Summer of 2009

Wambo, Kathryn Ann 09 September 2010 (has links)
No description available.
17

Remote Sensing of Cyanobacteria in Case II Waters Using Optically Active Pigments, Chlorophyll a and Phycocyanin

Randolph, Kaylan Lee 27 March 2007 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Nuisance blue-green algal blooms contribute to aesthetic degradation of water resources and produce toxins that can have serious adverse human health effects. Current field-based methods for detecting blooms are costly and time consuming, delaying management decisions. Remote sensing techniques which utilize the optical properties of blue-green algal pigments (chlorophyll a and phycocyanin) can provide rapid detection of blue-green algal distribution. Coupled with physical and chemical data from lakes, remote sensing can provide an efficient method for tracking cyanobacteria bloom occurrence and toxin production potential to inform long-term management strategies. In-situ field reflectance spectra were collected at 54 sampling sites on two turbid, productive Indianapolis reservoirs using ASD Fieldspec (UV/VNIR) spectroradiometers. Groundtruth samples were analyzed for in-vitro pigment concentrations and other physical and chemical water quality parameters. Empirical algorithms by Gitelson et al. (1986, 1994), Mittenzwey et al. (1991), Dekker (1993), and Schalles et al. (1998), were applied using a combined dataset divided into a calibration and validation set. Modified semi-empirical algorithms by Simis et al. (2005) were applied to all field spectra to predict phycocyanin concentrations. Algorithm accuracy was tested through a least-squares regression and residual analysis. Results show that for prediction of chlorophyll a concentrations within the range of 18 to 170 ppb, empirical algorithms yielded coefficients of determination as high as 0.71, RMSE 17.59 ppb, for an aggregated dataset (n=54, p<0.0001). The Schalles et al. (2000) empirical algorithm for estimation of phycocyanin concentrations within the range of 2 to 160 ppb resulted in an r2 value of 0.70, RMSE 23.97 ppb (n=48, p<0.0001). The Simis et al. (2005) semi-empirical algorithm for estimation of chlorophyll a and phycocyanin concentrations yielded coefficients of determination of 0.69, RMSE 20.51 ppb (n=54, p<0.0001) and 0.85, RMSE 24.61 pbb (n=49, p<0.0001), respectively. Results suggest the Simis et al. (2005) algorithm is robust, where error is highest in water with phycocyanin concentrations of less than 10 ppb and in water where chlorophyll a dominates (Chl:PC>2). A strong correlation between measured phycocyanin concentrations and blue-green algal biovolume measurements was also observed (r2=0.95, p<0.0001).
18

Phylogenetic Analysis of the Heterocystous Cyanobacteria as Assessed by 16S and 23S Ribosomal RNA

Kenyon, Kyle Christopher 07 August 2003 (has links)
No description available.
19

Application of data-driven models in exploring cyanobacterial bloom risks in Lake Mälaren / Tillämpning av datadrivna modeller för att utforska cyanobakterieblomningsrisker i Mälaren

Herrera, Abigail Huertas January 2021 (has links)
Cyanobacteria are a unique organism, a bacterium that develop photosynthesis, thus it contains chlorophyll, a pigment commonly associated to algae. For this reason, cyanobacteria are also known as blue-green algae. One of the secondary metabolites of cyanobacteria is cyanotoxin, a substance which is hepatoxic, neurotoxic, and dermatoxic. The frequency and intensity of cyanobacterial blooms have been of increasing concern in the last decades for drinking water supply. There is a need to improve monitoring of cyanobacteria content at source water for drinking water supply and its indicators and correlation with other chemical, physical and biological parameters. This study aims to identify the potential cyanobacterial bloom risk in Lake Mälaren by determining the influential chemical and physical parameters using Random Forest in classification mode. The classification was done using the WHO Alert Level Frameworks and study cases for lakes in Sweden. The data used to model was downloaded from the website of the Swedish University of Agricultural Science. It comprises 33 monitoring stations from 1964 to 2020, 21 chemical parameters, including cyanobacteria biovolume and chlorophyll content. Given the heterogeneity of data, the monitoring stations were grouped into Clusters. Using the data, statistical, correlation, time series, and principal component analysis were performed. Through these methods, spatial, distribution and temporal analysis were obtained. Afterwards, several models were determined using Random Forest. However, the mean values of cyanobacteria distributed over time indicated a medium risk, the maximum values suggested high risk in several areas of the Lake. Maximum concentrations were present at the west and northeast of the Lake, where the major inflows from the Watershed are discharged. As the water flows through the basin, the concentration of cyanobacteria reduces by half, which suggested that the large and deep bays act as sedimentation ponds. A very high correlation was found between the Cluster 5 and 6, east and middle northeast of the Lake, respectively. Finally, the contributing factors identified after modelling cyanobacteria as target factor were chlorophyll, month, water temperature, oxygen content, transparency, NO2NO3N, TN/TP, Ca, Mg and Cl. / Cyanobakterier är unika organismer, bakterier som utvecklar fotosyntes, så de innehåller klorofyll, ett pigment som vanligtvis förknippas med alger. Av denna anledning är cyanobakterier också kända som blågröna alger. En av de sekundära metaboliterna av cyanobakterier är cyanotoxin, ett ämne som är hepatoxiskt, neurotoxiskt och dermatoxiskt. Frekvensen och intensiteten av cyanobakterieblomningar har varit ett ökande problem under de senaste decennierna för dricksvattenförsörjningen. Många vattenreningsverk mäter inte innehållet av cyanobakterier i vatten; medan andra kemiska, fysikaliska och biologiska parametrar mäts. Denna studie syftar till att identifiera den potentiella risken för cyanobakteriell blomning i Mälaren genom att bestämma de mest inflytelserika kemiska och fysikaliska parametrarna med hjälp av metoden Random Forest i klassificeringsläge. Klassificeringen gjordes med hjälp av WHO Alert Level Frameworks och olika studier av sjöar i Sverige. Data som användes för att modellera laddades ner från Sveriges Lantbruksuniversitets webbplats. Den omfattar 33 övervakningsstationer från 1964 till 2020, med 21 kemiska parametrar, inklusive cyanobakteriers biovolym och klorofyllhalt. Med tanke på heterogeniteten i data grupperades övervakningsstationerna i kluster. Med hjälp av data utfördes statistisk analys, korrelation, tidsserier och huvudkomponentanalys. Genom dessa metoder erhölls rumslig, distribution och tidsanalys. Efteråt bestämdes flera modeller med hjälp av Random Forest. Medelvärdena för cyanobakterier fördelade över tiden indikerade en medelrisk, medan maximivärdena antydde något annat. Maximala koncentrationer fanns i väster och nordost om Mälaren, där de stora inflödena från vattendelaren släpps ut. När vattnet rinner genom bassängen minskar koncentrationen av cyanobakterier till hälften, vilket tyder på att de stora och djupa vikarna fungerar som sedimentationsdammar. En mycket hög korrelation hittades mellan kluster 5 och 6, öster respektive mellan nordost om sjön. Slutligen var de viktigaste faktorerna som identifierades efter modellering av cyanobakterier som målfaktor klorofyll, månad, vattentemperatur, syrehalt, transparens, NO2NO3N, TN/TP, Ca, Mg och Cl.
20

Změny kvality vody v koupalištích ve volné přírodě a v koupacích oblastech v průběhu letní sezóny / Changes in water quality in outdoor swimming pools and swimming areas during the summer season

MARŠÁLKOVÁ, Alena January 2010 (has links)
Good quality of bathing water is an increasingly important factor taken into account when we choose summer vacations, a place to stay for a weekend or a weekend trip destination. In the Czech Republic, bathing waters may be divided according to the legal status into outdoor swimming pools, surface waters used for bathing (swimming areas), other water surfaces or artificial pools. In my thesis I dealt only with outdoor swimming pools and swimming areas. The difference between them lies in the fact that outdoor swimming pools have their own operators who monitor water quality and provide other services in the waterside. Usually there is a fee charged. Swimming areas have no operators and water quality monitoring is placed under the responsibility of regional public health authorities. In the Czech Republic, at present, 188 outdoor swimming pools and swimming areas have been monitored on a regular basis each bathing season. For my research I chose four sites located in the South Bohemian region and four sites in the South Moravian region. For each of these eight sites, I collected results of laboratory analyses, including categories of water quality in bathing seasons of the past five years, it means from the year 2005. With these obtained data I assessed the water quality development both during the bathing season of 2009 and its evolution over the past five years. On the basis of particular categories of water quality I also tried to compare water quality in the South Bohemian and the South Moravian region and also to compare water quality between individual sampling points in one locality. Another aim was to evaluate some measures and interventions made in order to improve water quality. I focused particularly on the pond Olšovec in the South Moravian region and the VN (water reservoir) Orlík in the South Bohemian region. The results do not show any prominent changes in water quality both during the bathing season 2009 and over the past five years. Pronounced fluctuations in water quality were recorded only at certain locations during the 2007 bathing season. Not even between individual regions significant differences in water quality were found. The proportion of individual water quality categories in the two regions did not differ by more than 4%. We can therefore say that water quality in selected localities in the South Bohemian and South Moravian regions is comparable. As for certain measures and interventions implemented to improve water quality, it is important to focus also on the wider neighborhood of the locality, because it could also be a source of substances worsening water quality.

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