Thesis (Ph.D.)--Delft University of Technology, 2006. / Vita. Includes bibliographical references (p. 239-256).

Thesis (M. Sc. (Ichthyology and Fisheries Science))--Rhodes University, 2006.

Thesis (M.E.)--University of Canterbury, 1997. / Typescript (photocopy). Includes bibliographical references (leaf 39). Also available via the World Wide Web.

Thesis (M.S.)--University of West Florida, 2006. / Title from title page of source document. Document formatted into pages; contains 110 pages. Includes bibliographical references.

Made available in DSpace on 2014-06-11T19:30:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-08-18Bitstream added on 2014-06-13T19:00:41Z : No. of bitstreams: 1 figueiredo_fv_dr_jabo.pdf: 435317 bytes, checksum: 69fb7e009fc30d94a576f4bd9b3535a4 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A salmonelose é uma das doenças de origem alimentar mais freqüente e considerada uma das zoonoses mais relevantes para a saúde pública em todo o mundo. A Organização Mundial de Saúde (OMS) assinalou aumento alarmante de estirpes de Salmonella resistentes aos antibióticos devido ao seu uso abusivo em criações intensivas, especialmente nas aquícolas. Diante do exposto, o escopo deste trabalho foi o de isolar e identificar a resistência plasmidial em bactérias do gênero Salmonella, em amostras de água de dois ambientes estuarinos, um do Norte (Acaraú) e outro do Sul (Jaguaribe) do Estado do Ceará, ambos com atividades de carcinicultura. Durante sete meses, de novembro de 2006 a maio de 2007, foram coletadas 84 amostras de água dos dois estuários. A pesquisa de Salmonella seguiu a metodologia do “Bacteriological Analytical Manual”. As salmonelas foram testadas quanto à susceptibilidade a dez antimicrobianos: Ácido nalidíxico, Ampicilina, Ciprofloxacina, Ceftriazona, Cloranfenicol, Gentamicina, Imipenem, Nitrofurantoína, Sulfametoxazol e Tetraciclina. A Concentração Inibitória Mínima dos antibióticos seguiu a técnica de macrodiluição em caldo. Em atividade de base, mediu-se o pH, a temperatura e a salinidade da água. Foram confirmadas 103 cepas de Salmonella, 90 no Rio Acaraú e 13 no Rio Jaguaribe, pertencentes aos sorovares: S. Newport, S. Saintpaul, S. Panama, S. Rubislaw, S Albany, S. Anatum, S. Corvallis, S. Madelia. O Rio Acaraú apresentou-se mais contaminado do que o Rio Jaguaribe, onde foram encontradas cepas resistentes a antimicrobianos, com um percentual de 25% para resistência plasmidial, e 75% para a cromossômica. Esses resultados ressaltam dois problemas de saúde pública: a presença de cepas de Salmonella resistentes e a possibilidade de contaminação humana pelo consumo dos crustáceos. Somado a isso,... / Salmonellosis is one of the most common foodborne diseases, was considered and the most important for public health authorities throughout the world. The World Health Organization (WHO) recently drew attention to the rapid increase in Salmonella strains resistant to antibiotics employed in farming activities, especially in aquaculture. Thus, the objective of this study was to test the antimicrobial susceptibility of Salmonella strains isolated from water samples collected in the estuaries of the Acaraú and Jaguaribe rivers (respectively in the north and south of Ceará State, Brazil), both of which are subject to extensive shrimp farming. Eighty-four samples were collected between November 2006 and May 2007. The susceptibility tests were performed following the guidelines of the Bacteriological Analytical Manual (BAM). The strains were exposed to 10 different antibiotics: nalidixic acid, ampicillin, ciprofloxacin, ceftriaxone, chloramphenicol, gentamicin, imipenem, nitrofurantoin, sulfamethoxazole and tetracycline. The minimum inhibitory concentration of the antibiotics was determined with the broth macrodilution method. In base activity, mensure the factores as Temperature, salinity and pH values were registered for all water samples. One hundred three Salmonella strains were isolated (Acaraú n=90; Jaguaribe n=13) belonging to the serotypes S. Newport, S. Saintpaul, S. Panama, S. Rubislaw, S Albany, S. Anatum, S. Corvallis and S. Madelia. Thus, the Acaraú river was more severely contaminated than the Jaguaribe river, where strains resistant to antimicrobial were found in a rate of 25% to plasmid resistance and 75% to chromosomal resistance. These results show up two problems of public health: the presence of resistant strains of Salmonella and the possibility of human contamination though crustacean consumption. In addition to this,...(Complete abstract click electronic access below)

Compostos butílicos de estanho (BTs) estão na lista dos contaminantes impactantes relacionados ao ambiente marinho. Sua ampla distribuição associada à elevada toxicidade faz com que o monitoramento desses compostos no ambiente costeiro seja de fundamental importância. A ocorrência de BTs foi verificada em sedimentos superficiais, material particulado em suspensão e nos tecidos (fígado e brânquias) de três espécies de bagres estuarinos: Cathorops spixii, Aspistor luniscutis e Genidens genidens; amostrados em 8 estuários da região sul e sudeste brasileira. As análises foram realizadas através de GC-PFPD, seguindo padrões de controle de qualidade analítico e onde foi constatada a ocorrência de efeito matriz sobre o sistema analítico a partir da quantificação das amostras de tecido. Dentre os estuários amostrados, verificou-se um maior impacto dos BTs sobre os sistemas estuarinos de Paranaguá e Itajaí, em decorrência da presença destes compostos em todos os compartimentos ambientais analisados. As três espécies investigadas puderam ser consideradas como biomonitoras da presença de BTs no ambiente, uma vez que são passíveis de assimilação destes compostos, mesmo em organismos amostrados em regiões distantes de potencias fontes de entrada. Os efeitos sobre a fisiologia de C. spixii amostrado em Paranaguá também foi investigada a partir do uso de biomarcadores no fígado desses organismos, constatando um impacto associado à presença destes contaminantes no sistema. / Butyltin compounds (BTs) are in the list of related contaminants striking marine environment. Their widespread distribution associated with high toxicity causes the monitoring of fundamental importance. The occurrence of BTs were checked through superficial sediments, suspended particulate matter and tissues (liver and gill) analysis on three estuarine catfishes: Cathorops spixii, Aspistor luniscutis e Genidens genidens; sampled in eight estuaries from Brazilian south and southeast coast. Analysis were carried by GC-PFPD, following quality control procedures, where was verified the presence of matrix effect over the system from tissues quantification. Among estuaries, the major impact was found in Paranaguá-PR and Itajaí-SC, due the presence of these compounds in all investigated compartments. These three catfish species have shown good biomonitors of BTs presence once were liable of uptake, even in groups sampled far from potential BTs sources. The effects over C. spixii physiology were also checked in Paranaguá from the use of biomarkers on liver of these organisms, noting the impact related with the presence of these compounds on the system.

Orientador: Wanilson Luiz Silva / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-22T15:39:08Z (GMT). No. of bitstreams: 1 Nizoli_EricoCasare_D.pdf: 3439410 bytes, checksum: 6e05f3840a6ddac0203d12e536c08876 (MD5) Previous issue date: 2013 / Resumo: Durante as últimas décadas, efluentes industriais têm sido lançados no sistema estuarino de Santos-Cubatão, onde os rios Cubatão e Morrão são os principais receptores das descargas industriais. Diversos estudos foram realizados nos sedimentos do rio Morrão, já sendo bem conhecida a geoquímica da concentração total dos elementos neste ambiente. Os elevados níveis de ferro e fósforo de origem antrópica nestes sedimentos colocam este ambiente em um patamar científico cujos processos físico-químicos dominantes ainda são desconhecidos. No presente estudo, buscou-se identificar os processos que ocorrem na partição água intersticial-sedimentos em ambientes estuarinos impactados e o papel que a alta concentração de ferro e fósforo desempenha na variabilidade geoquímica tempo-espacial desta partição. Para tanto, foram investigados a dinâmica multi-elementar nos sedimentos, nas águas intersticiais, características fisico-químicas, matéria orgânica, sulfetos volatilizados por acidificação (AVS) e metais simultaneamente extraídos (SEM), granulometria e mineralogia mensalmente durante o período de onze meses, em dois ambientes do rio Morrão, sistema estuarino de Santos-Cubatão. Adicionalmente, foi desenvolvido um dispositivo para amostragem temporal de água intersticial por equilíbrio difusivo com sistema de coleta de amostra/recarga e uma proposta de mini-coluna para extração em fase sólida para a determinação de metais por ICP-MS em águas salinas. Os resultados obtidos demonstraram que o amostrador de água intersticial por equilíbrio difusivo proposto neste estudo é adequado para o emprego em trabalhos onde se pretende coletar temporalmente água intersticial sem perturbar os sedimentos e onde há a necessidade de um maior volume de amostra, o que não pode ser conseguido empregando amostradores apresentados pela literatura com funcionamento semelhante. Os dados do estudo sobre extração em fase sólida para determinação de metais em águas salinas por ICP-MS demonstraram que a mini-coluna com resina quelante proposta neste trabalho é eficaz em remover a matriz salina, apresentando precisão e exatidão adequadas aos níveis de analito presentes nas amostras. Já os resultados obtidos no estudo sobre a partição água intersticial-sedimentos em ambientes estuarinos impactados mostraram a existência de variações geoquímicas espaço-temporais para elementos maiores, menores e traços nos sedimentos. Assinaturas geoquímicas discriminantes foram observadas entre as populações de amostras VG (sedimentos expostos durante menor maré - borda do canal) e CN (sedimentos permanentemente submersos). Foi observado ainda que os elementos estudados se agrupam (análise de componente principal - PCA) de acordo com três fontes distintas (natural, indústrias siderúrgica e de fertilizantes). Variação espacial e temporal também foi identificada para a água intersticial, indicando que a autigênese de vivianita e magnetita estão entre os principais fatores controladores dos metais na água intersticial nos diferentes ambientes. Fases secundárias sulfetos (AVS) também exercem ação controladora dos metais na interface sedimento-água intersticial. Contudo, magnetita e vivianita apresentam-se como importantes retentores de metais na fase sólida, cuja cristalização autigênica é decorrente de introdução antrópica de Fe e P em grande escala no ambiente sedimentar do estuário do rio Morrão / Abstract: During the last decades, industrial effluents have been discharged into the estuary of Santos-Cubatão, where Cubatão and Morrão rivers are the main receivers of industrial discharges. Several studies were made in sediments of Morrão River, being already well known the geochemistry of the total concentration of the elements in this environment. The high levels of iron and phosphorus of anthropogenic origin in sediments, putting the environment on a scientific level in which dominant physical and chemical processes are still unknown. In the present study, we sought to identify the processes that occur in the pore water-sediment partition in estuaries impacted and the role that the high concentration of iron and phosphorus plays in the time and spatial geochemical variability. Therefore, we investigated the multi-elemental dynamics in sediments, interstitial waters, physico-chemical, organic matter, AVS and SEM, particle size and mineralogy, monthly, during the period of eleven months, in two places of Morrão river, Santos-Cubatão estuarine system. Additionally, we developed a device for temporal sampling of interstitial water by diffusive equilibrium system with sampling/recharging and a proposal for a mini-column for solid phase extraction for the determination of metals by ICP-MS in saline waters. The results showed that the pore water sampler for diffusive equilibrium proposed in this study is suitable for employment in investigations where it is necessary to collect temporally pore water without disturbing sediment and when there is a need for a larger sample volume, which cannot be achieved by employing samplers presented in the literature that operate similarly. Data from the study of solid phase extraction for the determination of metals in saline waters by ICP-MS showed that the mini-chelating resin column proposed in this study is effective in removing the salt matrix, with adequate accuracy and precision levels of analyte present the samples. Since the results obtained in the study of the pore water-sediment partition in estuaries impacted showed the existence of spatial and temporal geochemical variations for major, minor and trace elements in sediments. Discriminant geochemical signatures were also observed among the sample populations VG (sediments exposed during low tide - canal edge) and CN (permanently submerged sediments). It was also observed that the studied elements are grouped (Principal component analysis - PCA) according to three separate sources (natural, steel and fertilizer industries). Spatial and temporal variation was also identified for the interstitial water, indicating that the authigenesis of vivianite and magnetite are the main controlling factors of metals in the pore water in different environments. Secondary sulfide phases (AVS) also exert controlling metals in the interface sediment-pore water. However, magnetite and vivianite present themselves as important scavengers of metals, which authigenic crystallization is due to anthropogenic introduction of Fe and P large-scale sedimentary environment in the Morrão estuary / Doutorado / Geologia e Recursos Naturais / Doutor em Ciências

M.Sc. / Estuaries are regarded as South Africa's most productive ecosystems due to the important functions that they perform, such as providing nursery areas and feeding sites for juvenile macro-invertebrate and fish species. Furthermore, ecologically healthy estuaries are not only of critical importance since they facilitate the provision and recirculation of nutrients, they also provide conduits for catadromous or anadromous fish and act as buffers during floods. In South Africa these functions are continuously threatened by residential and/or industrial developments. It is thus essential to determine the ecological integrity (structure and function) of these systems. An ecological integrity study was carried out on the Mvoti Estuary, KwaZulu-Natal during 2004/2005. An ecological integrity study was also carried out on the Amatigulu/Nyoni Estuary, KwaZulu–Natal during the same period and was used as a reference study. The ecological integrity of the Mvoti Estuary was assessed in terms of the effects of selected abiotic drivers on specific biological responses. The study was carried out according to the guidelines of the ecological reserve determination methodologies and the resource directed measures for aquatic resources as set out by the Department of Water Affairs and Forestry. Surveys were carried out during low flow (September 2004) and high flow (March 2005) periods. Abiotic and biotic monitoring was carried out at four sites on the Mvoti Estuary and five sites on the Amatigulu/Nyoni Estuary. The abiotic components, such as the substrate composition and physico-chemical properties of the water and sediment, was analysed using standard methods. Biological monitoring included the study of the benthic macro-invertebrate-, ichthyofaunal- and avifaunal communities. The biotic and abiotic components were analysed using various indices, where applicable. The ecological integrity of a system can be assessed on the basis of its ability to carry out its natural functions. Results show that various anthropogenic activities in the upper reaches of the Mvoti River contributed to the highly modified state of the Mvoti Estuary. The abiotic drivers of the aquatic system that contributed to the modified state of the Mvoti Estuary is unacceptable water quality, a loss and/or modification of habitat and an altered hydrological pattern. As a result of the abiotic drivers, results show that the xi ichthyofaunal-, macro-invertebrate- and, to a lesser degree, the avifaunal communities also reside in a modified state. Physico-chemical, geomorphological and hydrological changes in this system resulted in the Mvoti Estuary suffering a loss in both its biological and ecological function as well as aesthetic value. It is apparent from the above that there is not only a need for rehabilitation, but also a need for an effective and continuous management strategy. This management strategy can only be successful if the biomonitoring of the system includes the effects at both economical and social levels.

Les estuaires ont été soumis à une forte pression humaine qui a entraîné la présence de polluants dans leurs eaux et sédiments, par exemple les métaux traces. Les estuaires du Golfe de Gascogne n’en sont pas une exception et les estuaires d’Ibaizabal et de la Gironde sont bien connus pour avoir des concentrations élevées de métaux. Dans ce contexte, les programmes de surveillance de l’environnement se sont appuyés sur l’utilisation des moules et des huîtres comme espèces sentinelles, car les analyses chimiques et biologiques de leurs tissus permettent d’évaluer l’état général de santé de leur environnement. Dans le but d’acquérir une meilleure compréhension des interactions entre la bioaccumulation et des effets toxiques du cuivre (Cu) et de l’argent (Ag) dans les huîtres Crassostrea gigas, ainsi que l’influence de facteurs environnementaux, le présent travail présente une étude de terrain et trois expériences de laboratoire. Parmi les résultats obtenus, on peut souligner que : (I) même si les huîtres et les moules peuvent indiquer correctement l’état de santé des estuaires du Golfe de Gascogne, une accumulation clairement plus élevée de métaux se produit dans les huîtres que dans les moules, (II) la voie d’exposition (directe ou alimentaire)induit des réponses de différentes intensités dans les huîtres, (iii) la toxicité de l’Ag est renforcée par la présence accrue de Cu dans les huîtres et (IV) la salinité a un faible effet sur la toxicité des métaux dans les huîtres. / Estuaries have been subjected to a high human pressure which has led to the presence of pollutants in their waters and sediments including trace metals. The estuaries in the Bay of Biscay do not constitute an exception of this situation and the Ibaizabal and Gironde Estuaries are both very well known for having high metal concentrations in different compartments. In this context, environmental health monitoring programmes have relied on the use of mussels and oysters as sentinel organisms because chemical and biological analyses of their tissues allow assessing the general health status of their surrounding environment. The present work aims at acquiring a deeper understanding of the interactions between bioaccumulation and the toxic effects of copper (Cu) and silver (Ag) in oysters Crassostrea gigas, as well as the effects that environmental factors may have on them, For this, one field study and three laboratory experiments have been carried out. Among the most relevant results obtained it can be highlighted that: (I) both oysters and mussels are useful to properly indicate the health status of estuaries of the Bay of Biscay, yet higher accumulation of metals occurs in oysters than in mussels, (II) the intake pathway (watercolumn and/or food) induces different response intensities in oysters (III) the toxicity of Ag is enhanced in the presence of Cu in oysters and (IV) salinity has a low effect on the toxicity of both metals in oysters.

Estuaries are dynamic on many spatial and temporal scales. Distinguishing effects of unpredictable events from cyclical patterns can be challenging but important to predict the influence of press and pulse drivers in the face of climate change. Diatom assemblages respond rapidly to changing environmental conditions and characterize change on multiple time scales. The goals of this research were to 1) characterize diatom assemblages in the Charlotte Harbor watershed, their relationships with water quality parameters, and how they change in response to climate; and 2) use assemblages in sediment cores to interpret past climate changes and tropical cyclone activity. Diatom assemblages had strong relationships with salinity and nutrient concentrations, and a quantitative tool was developed to reconstruct past values of these parameters. Assemblages were stable between the wet and dry seasons, and were more similar to each other than to assemblages found following a tropical cyclone. Diatom assemblages following the storm showed a decrease in dispersion among sites, a pattern that was consistent on different spatial scales but may depend on hydrological management regimes. Analysis of sediment cores from two southwest Florida estuaries showed that locally-developed diatom inference models can be applied with caution on regional scales. Large-scale climate changes were suggested by environmental reconstructions in both estuaries, but with slightly different temporal pacing. Estimates of salinity and nutrient concentrations suggested that major hydrological patterns changed at approximately 5.5 and 3 kyrs BP. A highly temporally-resolved sediment core from Charlotte Harbor provided evidence for past changes that correspond with known climate records. Diatom assemblages had significant relationships with the three-year average index values of the Atlantic Multidecadal Oscillation and the El Niño Southern Oscillation. Assemblages that predicted low salinity and high total phosphorus also had the lowest dispersion and corresponded with some major storms in the known record, which together may provide a proxy for evidence of severe storms in the paleoecological record.