[pt] A presente dissertação tem como objetivo realizar um levantamento sobre o relevo de fundo, o tipo de material e a qualidade dos sedimentos quanto a contaminação, da Lagoa de Jacarepaguá, Rio de Janeiro, para auxiliar os programas ambientais de revitalização do Complexo Lagunar da Baixada de Jacarepaguá, que estão sendo desenvolvidos na área, focando as Olimpíadas de 2016. Na primeira etapa realizou-se a batimetria da Lagoa. Foram adquiridas profundidades georreferenciadas em campo e gerados modelos batimétricos em 2 e 3 dimensões, nos quais foram identificadas cavidades e um platô de baixa profundidade no interior da Lagoa. Na segunda etapa foram coletadas amostras de sedimentos da Lagoa, em variadas profundidades, para os ensaios da caracterização geotécnica. Com estes resultados identificou-se a presença predominante de 2 tipos de sedimentos, arenosos localizados no platô raso e siltosos nas cavidades, e alto teor de matéria orgânica e baixa densidade nas amostras siltosas. Complementarmente, foram ensaiadas duas amostras arenosas para determinação dos parâmetros de permeabilidade e de resistência ao cisalhamento, visando gerar dados adicionais para possível aproveitamento deste material como aterro, caso dragado. Na terceira, e última etapa, foi realizada uma nova coleta de sedimentos, para análise química dos metais Bário, Cádmio, Chumbo, Cobre, Cromo, Ferro, Manganês, Mercúrio, Níquel e Zinco e Hidrocarbonetos Policíclicos Aromáticos (HPA’s), cujos resultados indicaram uma acumulação de alguns metais na área de influência de deságüe do Arroio Pavuna. Concatenando os resultados obtidos nas 3 etapas, considerase necessário e emergencial o cessamento das descargas de efluentes, nos rios afluentes à Lagoa, e a dragagem do sedimento arenoso localizado no platô, resultando em um canal central mais profundo, um aumento da coluna d’água que implicará no melhoramento do fluxo de troca de água entre a Lagoa e o mar, acelerando a recuperação do ecossistema lagunar de uma forma geral. / [en] The present dissertation aims at conducting a survey on the bottom morphology, the material type and quality of sediment contamination, in the Jacarepaguá Lagoon, Rio de Janeiro, to assist the environmental programs working on the revitalization the Lagoon area, focusing on the 2016 Olympics. In the first stage the bathymetry of the Lagoon was executed. Georeferenced depth measurements were acquired in the field and bathymetric models in 2 and 3 dimensions were generated, where cavities and a shallow plateau inside the Lagoon were identified. In the second stage, sediment samples of the Lagoon were collected - from varied depths - for the geotechnical characterization tests. Based on the results, the presence of two predominant types of sediments was identified, sandy sediments located on the shallow plateau and silty sediments on the cavities, as well as high content of organic matter and low density in silty samples. In addition, two sandy samples were tested to determine the permeability and shear strength parameters in order to gather additional data for possible use of this material in civil construction (if dredged). In the third and final stage new sediment samples were collected for chemical analysis of the metals Barium, Cadmium, Lead, Copper, Chromium, Iron, Manganese, Mercury, Nickel and Zinc as well as Polycyclic Aromatic Hydrocarbons (PAH s). The results indicated an accumulation of some metals in the drainage area of the Pavuna Creek. Concatenating the results obtained in these three stages, it is considered necessary and urgent to stop the effluent discharges into the Lagoon s tributary rivers as well as to dredge the sandy sediment located in the plateau, that would result in a deeper central channel, an increase of water column leading to an improved flow of water exchange between the Lagoon and the sea, accelerating the recovery of the Lagoon s ecosystem in general.

Este trabalho tem como objeto de estudo, a relação entre fatores sócio-ambientais e a pesca artesanal nos setores norte (Iguape) e sul (Cananéia) do Complexo Estuarino-Lagunar de Cananéia-Iguape (SP), considerando as mudanças hidroquímicas provocadas pela água que adentra o sistema através Valo Grande, um canal artificial que drena parte água do Rio Ribeira de Iguape para o Mar Pequeno, junto ao município de Iguape. Os parâmetros hidrológicos abordados foram: penetração de luz, temperatura, salinidade, oxigênio dissolvido, pH, MPS e nutrientes dissolvidos obtidos em diferentes profundidades. Os dados relativos à atividade pesqueira e perfil social dos pescadores foram obtidos por meio de entrevista semi-estruturada, com perguntas fechadas e abertas junto às comunidades caiçaras de Cananéia e Iguape. Os resultados ambientais mostraram diferenças hidrológicas importantes entre os dois setores, com baixa salinidade no setor norte, sob maior influência do canal do Valo Grande, enquanto a porção sul preserva as características estuarinas, porém sinais da interferência do setor norte já estão sendo sinalizados no sul, o que pode ser verificado junto a dados pretéritos do corpo hídrico. As espécies alvo de pesca encontradas nos dois setores do sistema também indicaram as alterações ambientais, mostrando características locais e variações sazonais. Foi verificado que os pescadores adaptaram-se às modificações ambientais, alternando as artes de pesca ao longo do ano e, investindo em embarcações, motores e petrechos de pesca, dando continuidade à atividade. Avaliando-se o perfil dos pescadores urbanos, foram verificadas condições sócio-econômicas que permitem viii que a maioria de suas residências seja de alvenaria, dispondo de abastecimento de água e energia provenientes da rede pública, porém a maioria dos entrevistados interromperam seus estudos. Este estudo evidenciou a dificuldade dos pescadores em ter o sustento somente da atividade pesqueira praticada, comprometendo assim, a sobrevivência desta tradição, e desestimulando o desenvolvimento deste setor. Esta situação também leva ao registro de um perfil diferenciado de caiçara, marcado pelo desempenho de outras atividades além da pesca. Assim, foi possível observar que diante de mudanças, extremas ou não, o comportamento humano estará sempre interligado ao ambiental, os quais estão em constante renovação, caracterizando a cultura de gerações. A economia solidária estabelecida por meio de uma cooperativa, ou de ações apoiadas por políticas públicas, constituem alternativas que contribuem à solução de alguns problemas que afetam as comunidades estudadas. Certamente, ações participativas que insiram o pescador nos projetos gestão e preservação ambiental, permitindo uma maior atuação junto às políticas públicas locais, contribuirão à sustentabilidade ambiental, sócio-cultural e econômica. / This work aims to study the relations between socio-environmental factors and the artisanal fishery in the sectors north (Iguape) and south (Cananéia) of the Cananéia-Iguape Estuarine-Lagoon Complex, considering the hydrochemical changes caused by the water that enters within the system through Valo Grande, an artificial channel that drains part of the Ribeira de Iguape River waters to Mar Pequeno, Iguape. The hydrological parameters studied were: penetration of light, temperature, salinity, dissolved oxygen, pH, suspended particulate matter and dissolved nutrients obtained in different depths. The data concerning the fishery activities and social profile of the fishermen were obtained through semi-structured interviews, with closed and open questions made with the communities of Cananéia and Iguape. The environmental results showed important hydrological differences between the two sectors, with low salinity in the northern sector, under greater influence of Valo Grande Channel, while the southern sector still preserves estuarine characteristics. However, signals of the north interference are already being noticed in the south, this can be verified by comparing past data of the water body. The fishery target species found in the two sectors of the system also pointed to environmental changes, showing local characteristics and seasonal variations. It was verified that the fishermen adapted to the environmental changes by changing the fishery type throughout the year and investing in boats, engines and fishery equipment, this way continuing with the activity. Socio-economical conditions that allow most of the residences to be made of masonry, having energy and water supplied by the public services, were verified evaluating the fishermen profile. However most of the fishermen had their formal education interrupted. This study shows the difficulty of the fishermen to have their livelihood only by fishing, therefore compromising the survival of this tradition and discouraging the development of this sector. This situation also leads to register a differentiated fishermen profile, marked by the realization of other activities besides fishery. So, it was possible to observe that faced with changes, extremes or not, the human behavior will always be linked to the environment, they are in constant renovation, x characterizing the culture of generations. The solidarity economy established by a cooperative or by actions supported by public politics constitutes alternatives that contribute to the solution of some problems that affect this community. Certainly, participative actions, that insert the fishermen in management and environmental preservation projects, allowing a greater participation in local public policies, will contribute to the environmental, socio-cultural and economic sustainability.

Worldwide research of bottlenose dolphins (Tursiops truncatus) has led to varied definitions and terminology regarding ways to group dolphins for study and management. An understanding of the demographic history and population structure of bottlenose dolphins residing within the Indian River Lagoon Estuary System (IRLES), Florida, is needed to help define the IRLES dolphin population: ecotype, population, or community. Using mitochondrial DNA sequencing and microsatellite genotyping, this study detected: (1) genetic differentiation between estuarine and coastal individuals (FstmtDNA=0.414, Fstmsat=0.057; p<0.05; K=2), (2) genetic differentiation between the Indian River Lagoon (IRL) and Mosquito Lagoon (ML) (FstmtDNA=0.0201, Fstmsat=0.0234; p<0.09), and (3) minute undefined sub-structure within the IRLES (FstmtDNA=-0.00 -0.0379, Fstmsat=0.00 - vii 0.0445; p>0.1). Additionally, within ML this study detected non-mixing cohabitation of two potential ecotypes, estuarine and coastal. These findings raise many questions regarding how dolphins are presently categorized and managed which are critical to population assessments including abundance, vital rates, and health. / by Sarah E. Rodgers. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Ce travail a pour objectif d’étudier la biodiversité et la dynamique du zooplancton en relation avec les paramètres environnementaux dans la lagune Ghar El Melh au niveau de 5 stations à travers un suivi bimensuel allant de février 2011 à janvier 2012. Cette étude vise également à déterminer l’impact des régimes alimentaires à base de microalgues nuisibles, en conditions expérimentales, sur la survie, le comportement et la reproduction du copépode Calanoïde Acartia clausi collecté dans la lagune Ghar El Melh pendant la saison printanière.L’analyse hydrologique du milieu a mis en évidence une variation saisonnière de la totalité des paramètres avec des valeurs importantes de la température, de la salinité, du pH et de la Chl a en été et des teneurs élevées en nutriments en automne/hiver. L’étude spatio-temporelle du zooplancton a révélé la présence de 23 groupes zooplanctoniques dominés par les copépodes (37,25%) et les ciliés (21,09%). La lagune représente également un lieu de reproduction pour plusieurs espèces compte tenu de l’abondance du méroplancton tels que les larves de lamellibranches (14,9%) et les véligères de gastéropodes (12,5%). La température, la salinité, les caractéristiques hydrodynamiques, la teneur en ammonium et la richesse trophique ont été les facteurs déterminants pour le développement du zooplancton. Les relations d’ordre trophique semblent avoir un effet important sur la distribution des copépodes, ciliés et rotifères. La communauté des copépodes a été composée par 13 espèces dominées par les espèces opportunistes Oithona nana (59,5%), Acartia clausi (21%) et Euterpina acutifrons (8,87%) dont les abondances et la saisonnalité semblent être tributaires, en plus de l’abondance des proies, des caractéristiques hydrologiques de l’eau notamment de la température et la salinité.Les essais portant sur l’impact des microalgues nuisibles sur Acartia clausi ont mis en évidence i) une réduction du taux de survie (55%) et du nombre d’œufs produits (3,9 ± 3,2 œufs femelle-1 j-1) due à Prorocntrum micans malgré l’importance de l’activité alimentaire et du taux d’éclosion des œufs ii) Une altération importante de l’activité alimentaire, de la reproduction et de la survie due à Prorocentrum lima dès le premier jour iii) une létalitè importante de la souche Ostreopsis ovata se caractérisant par la mortalité de tous les individus après 24 heures iv) une altération importante du mouvement (33,6%) observée dès le 8ième jour, accompagnée d’une production réduite d’œufs (2,8 ± 3,9 œufs femelle-1 j-1), un faible taux d’éclosion (27,9 ± 30,6%) et d’une réduction importante de la survie due à Alexandrium catenella. / The aim of this work is to study the biodiversity and seasonal distribution of zooplankton community along with environmental factors in Ghar El Melh lagoon at 5 stations by twice monthly sampling from February 2011 to January 2012. This study also focused on the impact of several diets based on harmful microalgae on the survival, behavior and reproduction of the Calanoïd copepod Acartia clausi collected from Ghar El Melh lagoon during spring under laboratory control.The hydrological caracteristics revealed a seasonal variation of all parameters with high water temperature, salinity, pH and Chlorophyll a in summer and high nutrient concentrations in autumn/winter. The study of spatial and temporal variation of zooplankton revealed the presence of 23 groups mainly dominated by copepods (37.25%) and ciliates (21.09%). High abundance of meroplankton such as bivalve larvae (14.9%) and gastropod veligers (12.5%) showed that the lagoon can be considered as a breeding place for several marines species. Temperature, salinity, hydrodynamic characteristics, ammonium concentration and abundance of prey were the determining factors for the development of zooplankton. Trophic relationships seem to have an important effect on the distribution of copepods, ciliates and rotifers. The copepod community was composed of 13 species chiefly represented by opportunistic species Oithona nana (59.5%), Acartia clausi (21%) and Euterpina acutifrons (8.87%). Abundance and seasonality of this opportunistic community seem to be related to the abundance of prey and hydrological characteristics of water such as temperature and salinity.Bioassay on Acartia clausi using several harmful microalgae species showed (i) reduction of survival rate (55%) and egg production (3.9 ± 3.2 eggs female-1 day-1) due to Prorocntrum micans despite the high feeding rate and egg hatching success (80%) ii) a high decrease of feeding, reproduction and survival rates observed after 1 day of exposure to the toxic Prorocentrum lima iii) a very high lethality of used Ostreopsis ovata strain causing the mortality of all copepods after only 24 hours iv) high movement alteration rate (33.6%) observed after 8 days of exposure to Alexandrium catenella, associated to a reduced egg production rate (2.8 ± 3.9 eggs female-1 day-1), a low hatching success (27.9 ± 30.6%) and a reduced survival rate.

Este trabalho relaciona alguns dos motivos edênicos que, a partir do mito da Idade de Ouro da humanidade apresentado por dois poetas da Antigüidade Clássica, Virgílio e Ovídio, que vai-se mesclar, na Idade Média, à descrição católica do Jardim do Éden e serão retomados com o descobrimento da América, repercutindo na colonização do Brasil, onde sua chama, ainda que débil, se mantém. Eles ressurgem no século XX, nomeadamente nos romances de Menotti Del Picchia: A filha do Inca e Kalum, o mistério do sertão. Obras de ficção científica, produzidas num período de efervescência do gênero, entremeadas de elementos fantásticos presentes no imaginário do sertão amazônico brasileiro, tais romances de Menotti Del Picchia afirmam a permanência entre nós dos ditos mitos. O Paraíso Terreal existe e está no Novo Mundo, particularmente em terras brasileiras, com suas águas rejuvenecedoras da provável fonte da juventude e com seus tesouros incalculáveis localizados no Eldorado. Tudo isso guardado e defendido por seres fabulosos, ente os quais as Amazonas guerreiras. Como conseqüência, vemos a alusão insistente à fertilidade, abundância e exuberância das terras brasileiras, com a diversidade de sua fauna e flora, à longevidade saudável de seus habitantes, à inocência da nudez dos primitivos moradores deste paraíso, à busca sôfrega pelas riquezas da Lagoa das Esmeraldas, do ouro e da prata no interior do continente e às índias guerreiras que pelejam ao longo de um rio, imediatamente associadas às Amazonas gregas, cuja força de comparação batizou tal rio e a região onde teriam sido vistas pelos primeiros conquistadores. Com os espanhóis, numa coloração mais viva, e mais esmaecida com os portugueses, essas peculiaridades não deixam de ser constantemente mencionadas ao longo dos primeiros séculos da exploração e colonização do novo continente, muitas delas ora alimentadas, ora acrescidas pelo testemunho - que lhes dá maior credibilidade - dos donos e conhecedores das novas terras: os índios americanos. Esses mitos redivivos estarão presentes ainda em nossa cultura no século XX, como comprovam os dois romances de Menotti Del Picchia aqui estudados. / This paper points out some of the edenic motives, which as of the myth of humanity\'s Golden Age described by two poets of the Ancient Classic, Virgill and Ovide, will blend, in the Middle Age, with the catholic description of the Garden of Eden and will be resumed with the discovery of America, echoing on the colonization of Brazil, where its flame, albeit weak, still remains. They reappear in the 20th century, namely in the romances of Menotti Del Picchia: A filha do Inca and Kalum, o mistério do sertão. Scientific fiction works, produced in a bubbling period of the sort, filled with fantastic elements present in the imaginary of the Brazilian Amazonian hinterland, those romances of Menotti Del Picchia affirm the permanence among us of the mentioned myths. The \"Terreal\" Paradise exists and it is in the new World, particularly in Brazilian lands, with its rejuvenating waters of the likely fountain of youth and with its invaluable treasures located in the \"Eldorado\". All of this kept and guarded by fabulous beings, among which the Amazon warriors. As consequence, we see the insistent allusion to the fertility, abundance and exuberance of Brazilian lands, with the diversity of its fauna and flora, to the healthy longevity of its inhabitants, to the innocence of the nudity of the primitive dwellers of this paradise, to the impatient search of the riches of the Lagoon of the Emeralds, of gold and silver in the heartland and the warrior Indians that fight along the river, immediately associated to the Greek Amazons, whose strength of comparison christened that river and the regions where they were allegedly seen by the first conquerors. With the Spanish, in a livelier color, and paler with the Portuguese, these peculiarities are constantly mentioned along the first centuries of exploration and colonization of the new continent, many of them at times nurtured, at times increased by word of mouth - which give them more credibility - of the owners and knowers of the new land: the American Indians. These ressurected myths will still be presented in our 20th century culture, as proven on these two romances of Menotti Del Picchia here studied.

Este trabalho experimental apresenta os resultados da avaliação do desempenho de uma instalação piloto, composta por reator UASB seguido de lagoa aerada aeróbia e lagoa de decantação, no tratamento dos esgotos afluente a ETE - Jundiaí, que contém elevada contribuição de despejos industriais. O reator UASB e a lagoa de decantação tem volume útil de 3,0 m3 e 2,0 m3, respectivamente. O volume da lagoa aerada aeróbia é variável entre 7,2 m3 e 21,6 m3 de modo a permitir variar o tempo de detenção hidráulica. O sistema foi avaliado em termos da eficiência de remoção de DQO, DBO5, sólidos suspensos, nitrogênio total, fósforo total e cor verdadeira para tempos de detenção hidráulica na lagoa aerada aeróbia variando entre 1,0 e 3,5 dias mantendo, tanto no reator UASB quanto, na lagoa de decantação o tempo de detenção constante em 8,0 horas e 1,8 dia, respectivamente. O sistema completo apresentou uma eficiência de remoção de DQO total entre 85% e 87%, de DBO5 total entre 92% e 96%, de SST entre 81% e 87%, de SSV entre 80 e 88%, de nitrogênio total entre 55 e 57%, de fósforo total entre 60 e 70% e de cor verdadeira entre 50 e 60%, para tempos de detenção hidráulica na lagoa aerada aeróbia variando entre 1,5 e 3,5 dias. O reator UASB foi responsável pela remoção de cerca de 50% da DQO total, 60% da DBO5 total e 40% dos SST do afluente, operando em média com um tempo de detenção hidráulica de 8,0 horas. As eficiências alcançadas no sistema completo produziram um efluente final com uma concentração de DQO total entre 170 e 230 mg/L, de DBO5 total entre 30 e 60 mg/L, de SST entre 30 e 45 mg/L, de SSV entre 24 e 40 mg/L, de nitrogênio total entre 24 e 28 mg NH3/L, de fósforo total entre 3,5 e 5,5 mg P/L e de cor verdadeira entre 375 e 600 mg Pt/L. O sistema pesquisado mostrou-se uma alternativa viável para o tratamento do esgoto afluente à ETE - Jundiaí e poderá resultar em redução da área e em menor consumo de energia que os hoje necessários na ETE - Jundiaí, que emprega um sistema composto por lagoas aeradas aeróbias seguidas de lagoas de decantação. / This experimental investigation was carried out in order to evaluate the performance of a pilot plant, composed of an UASB reactor followed by an aerated lagoon and a settling pond, treating the Wastewater Treatment Plant of Jundiaí city (WWTPJ) influent sewage, which contains in its composition an expressive amount of industrial effluents. The UASB reactor and settling pond have an useful volume of 3.0 m3 and 2.0 m3, respectively. The aerated lagoon volume is variable from 7.2 m3 to 21.6 m3 to make possible the hydraulic retention time variation. The COD, BOD5, suspended solids, total nitrogen, total phosphorus and true colour removal efficiencies of the system were evaluated when the aerated lagoon hydraulic retention time varied from 1.0 to 3.5 days and in the UASB reactor and settling pond was mainteined constant at 8.0 hours and 1.8 day, respectively. The range of removal efficiencies obtained in the system are: 85 - 87% for total COD, 92 - 96% for total BOD5, 81 - 87% for TSS, 80 - 88% for VSS, 55 - 57% for total nitrogen, 60 - 70% for total phosphorus, and 50 - 60% for true color, when the aerated lagoon hydraulic retention time varied from 1.5 to 3.5 days. The UASB reactor operating at 8.0 hours hydraulic retention time removes almost 50% of total COD, 60% of total BOD5 and 40% of TSS from the influent contents. The system performance lead to a final effluent with a total COD, total BOD5, TSS, VSS, total nitrogen, total phosphorus, and true color concentrations in the range of: 170 - 230 mg/L, 30 - 60 mg/L and 30 - 45 mg/L, 24 - 40 mg/L, 24 - 28 mg N/L, 3,5 - 5,5 mg P/L and 375 - 600 mg Pt/L, respectively. The system studied is a practicable alternative for the treatment of the WWTPJ influent sewage, probably with less area and energy saving whem compared to the WWTPJ current needs, which uses a system composed by an aerated lagoon followed by a settling pond

Wave and tides are important drivers of circulation, sediment transport and water exchanges between ocean and lagoon in atolls, which in turn, affect the formation and stability of reef islands. Through a combination of field measurements and numerical modelling, this thesis examines the wave- and tidally-induced processes at Rocas Atoll and their implications on sediment dynamics. This comprehends the morphological responses of reef islands, including the effects of sea level rise. Wave, current, tide and topo-bathymetric data were collected during three expeditions to Rocas Atoll, totaling 75 days of in situ measurements. A spectral wave model has been implemented and validated for the Rocas Atoll. Our results demonstrated that the mechanism of circulation and the wave propagation that affects the reef islands morphology are controlled by the interaction of wave climate with the atoll topography. Being under mesotidal setting, there is a strongly tide modulated process in Rocas. The offshore wave climate is dominated by southeast trade wind wave and swell from south and north mid-latitude hemispheres. The swell occurrence has a marked seasonality whereas the southeast wind waves persist during the whole year. Offshore waves are filtered by the reef rim resulting in a more homogenous lagoon wave climate, which is controlled by tide and reef topography. Offshore extreme events are promoted by energetic swells, either from north or south hemispheres. However, extreme events in the lagoon only occur when such offshore events are combined with spring high tide. Wind waves that persistently break on the windward side of the atoll plays an important role on the overall circulation. They pump water into lagoon creating wave- generated currents that flow from the windward to the leeward side of the atoll. A water level threshold exists due to the large tidal oscillation, blocking inflow by wave pumping at lower water levels. This results in periodic variations in the relative importance of tidal controls in lagoon circulation along a tidal cycle interval. Such mechanism described for Rocas Atoll can be extended to other similar mesotidal atolls. The reef islands are located on the leeward of the atoll and present higher morphological changes in response to northern swell. However, no significant net erosion was observed on daily and seasonal time scale, with eroded parts being compensated by accretion on adjacent parts. Conversely, Farol Island had a substantial accretion on a decadal time scale changing from an elongated ridge morphology to horse-shoe shape with three ridges and an intertidal central depression. The changes in the planform configuration were characterized by ocean shoreline erosion and lagoon shoreline progradation, representing net lagoonward migration. Cemitério Island remains stable for the same period, anchored by exposed consolidated sediments on both shores. Results indicate the resilient nature of reef islands and their potential adjustment to changes in boundary conditions. In terms of wave refraction, Rocas Atoll works as a platform reef due to its morphology. Wave vectors converge mainly on the leeward side and an interference zone can be observed from the windward side trough the lagoon. Such refraction pattern controls the location of reef islands and shingle bank on Rocas. Sea level rise displaces the wave convergence zone according to the incident wave incidence climate (swell or wind wave). This indicates that under sea level rise scenarios areas prone to sediment accumulation may become less stable, although not implying in the erosion of reef islands. The results provided an unprecedented dataset for Rocas Atoll, which improves the understanding about the mechanisms that control its reef islands morphodynamics and their ability adapt to changes in boundary conditions. / Os processos induzidos por ondas e marés em atóis são importantes forçantes da circulação, transporte de sedimentos e troca de água entre a laguna e oceano, que por sua vez, afetam a formação e estabilidade das suas ilhas recifais. Através da combinação de modelos numéricos e experimentos de campo, este trabalho teve por objetivo o estudo dos processos induzidos por ondas e marés no Atol das Rocas e suas implicações na dinâmica de sedimentos das ilhas recifais, considerando os efeitos do aumento do nível do mar. Experimentos de campo forneceram séries temporais de ondas, correntes, mares e informações topo-batimétricas ao longo de três expedições ao Atol das Rocas, totalizando 75 dias de levantamentos. Um modelo numérico de propagação de onda foi implementado e validado para a região. Os resultados demonstram que o mecanismo de circulação e de propagação de ondas, que afetam as ilhas recifais, é controlado pela interação do clima de onda com a topografia do atol, sendo fortemente modulados pelas flutuações de meso-maré. O clima de ondas ao largo do atol é dominado por vagas formadas pelos ventos alísios de sudeste e por ondulações geradas em latitude médias de ambos os hemisférios. A incidência das ondulações no atol apresenta uma forte sazonalidade enquanto que a vagas de sudeste persistem ao longo do ano. As ondas ao largo são filtradas pela borda do atol, resultando em um clima de ondas na laguna mais homogêneo e controlado pela maré e topografia do atol. Eventos extremos ao largo são ocasionados por ondulações energéticas tanto do hemisfério sul quanto do hemisfério norte. No entanto, os eventos extremos na laguna só ocorrem quando os eventos energéticos ao largo ocorrem em conjunto com maré alta de sizígia. As vagas que quebram constantemente no lado do atol exposto ao vento são importante forçantes na circulação geral do atol. A partir do processo de quebra, elas são responsáveis por bombear água para a laguna, criando intensas correntes geradas por ondas que fluem do lado exposto para o lado protegido. Este processo, modulado pela maré, resulta em variações periódicas da importância relativa da maré no controle da circulação. Foi também observada a presença de ondas longas dentro da laguna (infragravitacionais) provocada pela quebra do espectro de ondas incidente no recife. Através desses dados, o volume de fluxo de troca de água e o coeficiente de atrito no Barretão foram estimados. O mecanismo descrito para Rocas pode ser aplicado em outros atóis semelhantes sob regime de mesomaré, os quais ainda hoje têm sido pouco estudados. As ilhas recifais estão localizadas no lado protegido do atol e apresentam maiores modificações morfológicas em resposta a incidência de ondulações de norte. No entanto, não foi observado um balanço sedimentar negativo em escala diária e sazonal, com partes erodidas da ilha sendo compensadas por acresção nas partes adjacentes. Em escala decadal, a Ilha do Farol apresentou substancial acréscimo em área (59.6% em 75 anos), modificando sua forma alongada para uma forma de ferradura com formação de uma depressão central. Durante esse processo, o lado da ilha voltado para o oceano foi erodido, enquanto que o lado da laguna foi acrescido, caracterizando uma migração da ilha para a laguna. Não foram observadas modificações significativas na ilha do Cemitério, a qual está estabilizada atualmente pela presença de sedimentos consolidados expostos nos dois lados da ilha. Os resultados indicam que as ilhas são feições resilientes, capazes de se ajustar as mudanças nas condições de contornos. No processo de refração das ondas, devido a sua morfologia, o Atol das Rocas funciona com uma plataforma recifal. Os vetores de ondas convergem no lado protegido e zonas de interferência podem ser observadas no lado exposto e na parte central da laguna. A localização das ilhas e do banco Zulu está relacionada com o padrão de refração, que promovem locais favoráveis à deposição de sedimentos no atol. O aumento do nível do mar promove um deslocamento na posição de convergência das ondas de acordo com o tipo de onda incidente. Isto indica que neste cenário futuro, as áreas deposicionais podem se tornar mais instáveis no atol promovendo o deslocamento das ilhas, mas não necessariamente em uma erosão generalizada. Os resultados obtidos no desenvolvimento deste trabalho forneceram uma série de informações inéditas para o Atol das Rocas permitindo elucidar questões importantes acerca da capacidade de modificações das ilhas recifais em resposta aos processos oceanográficos dominantes no atol.

L’objectif principal de ce travail était de réaliser une étude écotoxicologique du complexe lac Ichkeul-lagune de Bizerte. Un recensement des pesticides agricoles les plus utilisés dans le bassin versant agricole a été effectué afin de déterminer les pesticides les plus problématiques. Le recensement effectué auprès des agriculteurs, des revendeurs de produits phytosanitaires et le commissariat régional de développement agricole de Bizerte a permis d’identifier les molécules les plus utilisées au niveau des zones agricoles du bassin versant du complexe lac Ichkeul – lagune de Bizerte: l’iodosulfurone, le mésosulfurone, le 2,4D, le glyphosate et le fénoxaprop comme matières actives des herbicides ; le tébuconazole et l’époxiconazole comme fongicide et la deltaméthrine matières active des insecticides. Ensuite, les concentrations en pesticides, HAP et PCB ont été déterminées. Les résultats ont montré une contamination au niveau de certains sites du complexe. Les stations situées dans la lagune de Bizerte ont des teneurs en HAP dépassant les limites tolérées. Les concentrations en pesticides dépassent les normes au niveau de quelques sites du lac Ichkeul. Enfin, l’impact de ces polluants sur les communautés microbiennes et la densité de nématodes a été déterminé. La CCA combinant les résultats des analyses chimiques et les données T-RFLP des communautés bactériennes met en évidence que les communautés bactériennes du lac sont influencées parles pesticides alors que celles de la lagune sont influencées par les HAP. La répartition des T-RFs montre la présence de T-RFs spécifiques dans les sites contaminés : le T-RF 114 bp caractérise le site le plus contaminé en pesticide, les microorganismes associés à ce T-RF correspondent probablement à des microorganismes résistants aux pesticides et capables de les dégrader. La composition des communautés bactériennes a été déterminée par pyroséquençage 454 sur les sites les plus représentatifs : le moins contaminé du complexe, le plus contaminé en HAP, le plus contaminé en pesticides et un site présentant une contamination multiple HAP-Pesticides. L’impact de la présence des pesticides sur la densité des nématodes libres marins a été étudié. L'analyse taxinomique des données de pyroséquençage regroupe les séquences dans 44 embranchements différents. En général, Proteobacteria étaient l’embranchement le plus dominant avec une prédominance de Gammaproteobacteria, Alphaproteobacteria et deltaproteobacteria dans les sédiments. Les communautés bactériennes des quatre sites ont 211 OTU commun. Le lac Ichkeul a été caractérisé par 219 OTU spécifique et la lagune de Bizerte 235 OTU. Le Site 2, le plus contaminé en pesticides présente l’abondance la plus élevée en nématodes libres marins. / The main objective of this work was to conduct an ecotoxicological study of the complex Ichkeul Lake-Bizerta lagoon. A survey of the most used agricultural pesticides in the watershed of the complex was conducted to determine the most problematic compounds. The survey of pesticides use with farmers, dealers of pesticides and the Regional Commissioner for Agricultural Development Bizerte has helped to identify the most used pesticides in agricultural areas of the watershed of the complex Ichkeul Lake-Bizerta lagoon: iodosulfuron, the mesosulfurone, 2,4D, glyphosate and fenoxaprop as herbicides active materials, tebuconazol epoxiconazol as fungicide active materials and deltamethrin as insecticides. Then, the concentrations of pesticides, PAHs and PCBs were determined in the sediment of the complex. The results showed a contamination of some complex sites. Stations located in the lagoon of Bizerte have a level of PAH in excess of permissible limits. Pesticide concentrations exceed the standards at some sites from the Ichkeul Lake. Finally, the impact of these pollutants on microbial communities and nematode density was determined. CCA combines the results of chemical analyzes and T-RFLP data of bacterial communities shows that the bacterial communities of the lake are influenced by pesticides while those of the lagoon are influenced by PAHs. The distribution of T-RFs showed the presence of specific T-RFs in contaminated sites: the T-RF 114 bp characterizes the most contaminated site in pesticides, microorganisms associated with the T-RF are probably microorganisms resistant to pesticides and capable of degrading this pollutant. The composition of bacterial communities was determined by 454 pyrosequencing of the most representative sites: the least contaminated of the complex, the most contaminated by PAH, the most contaminated by pesticides and a site with multiple PAH-pesticides contamination. The impact of the presence of pesticides on the density of free living marine nematodes was studied. The taxonomic analysis of the pyrosequencing data grouped the sequences into 44 different phyla. In general, Proteobacteria were the most dominant phyla with predominance of Gammaproteobacteria, Alphaproteobacteria and Deltaproteobacteria within the sediments. Besides Proteobacteria, there are a number of sequences affiliated to the following major phyla detected in all four sites: Chloroflexi, Bacteroidetes, Nitrospirae, Planctomycetes, Actinobacteria, Gemmatimonadetes, Firmicutes, Cyanobacteria, Spirochaetes, Acidobacteria. The bacterial communities of the four sites shared 211 common OTUs. The Lake Ichkeul was characterized by 219 specific OTUs and the Bizerta lagoon by 235 OTUs. Site 2, the most contaminated by pesticides has the highest abundance of free living marine nematodes.

Ce travail s’oriente vers la valorisation du traitement d’eaux usées à partir de piles à combustibles microbiennes (PCM) benthiques pour la production d’électricité. Cette technologie permet la production d’électricité à partir de micro-organismes électro-actifs (EA) et d’un substrat carboné qui peut être de l’eau usée.Quatre types d’eaux usées issues de l’activité anthropique sont sélectionnés. La présence de micro-organismes EA est mise en évidence par 2 méthodes électrochimiques. En condition réelle, le milieu lagunaire présente les meilleures performances électriques (6,6 mW/m²). Celui-ci propose l’environnement le plus favorable à l’installation dePCM benthiques in-situ. Les résultats montrent une forte influence des micro-algues sur l’activité des biofilms EA. Avec un cycle jour/nuit, cette production varie en suivant les cycles d’éclairage. Les micro-algues apportent l’oxygène nécessaire aux réactions cathodiques. Les PCM améliorent également la consommation de polluants du milieu cathodique.L’alimentation de petits dispositifs tels que des capteurs passe obligatoirement par une augmentation de la tension délivrée par les biopiles. Différentes techniques d’élévation de la tension (mise en série et en parallèle de plusieurs piles, convertisseurs DC/DC) sont analysées. Un capteur de température et d’humidité a fonctionné durant plus de 15 h directement alimenté par une de nos biopiles benthiques avec une puissance de 328 µW. Sa tension de sortie est augmentée par un convertisseur de type Flyback, passant de 560 mV à plus de 5,5 V. L’utilisation de PCM in-situ dans la lagune peut constituer une alternative à la production électrique et au traitement des eaux usées. / The work described in this document is oriented to enhancing the treatment of wastewater from benthic microbial fuel cell (BMFC) for electricity production. This technology allows the production of electricity from electro-active (EA) microorganisms and carbonated substrate which may be the wastewater.Four types of wastewater from human activity are selected. The presence of EA microorganisms is highlighted by two electrochemical methods. In real conditions, the lagoon environment has the best electrical performance (6.6 mW/m²).The lagoon environment offers the most favorable environment for installation BMFC in-situ. The results show a strong influence of microalgae on the EA biofilms activities and thus on the production of electricity. In lagoon conditions, with a day/night cycle, this production varies according to the lighting cycles. Microalgae bring oxygen necessary for cathode reactions at lower cost. BMFC also improve the consumption of pollutants including organics.Electrical supply by small devices such as sensors necessarily requires an increase of the voltage delivered by BMFC. The different voltage boosting techniques such as series and parallel connections of several units or the use of DC/DC converters are performed and analyzed. A temperature and humidity sensor worked for more than fifteen hours directly powered by a BMFC with a power of 328 µW. Its output voltage is increased by a flyback type DC/DC converter, from 560 mV to more than 5.5 V. The use of PCM in-situ in the lagoon can be an alternative to the power generation and the treatment of wastewater.

Les activités anthropiques ainsi que des phénomènes naturels sont à l’origine de risques avérés pour l’environnement. L'Indonésie est un pays archipélagique qui contient de nombreuses îles et régions côtières, où la croissance exponentielle des activités anthropiques a exposé l’environnement indonésien à de graves détériorations au cours des dernières décennies. Cette étude vise à explorer (qualitativement et quantitativement) les niveaux de contamination des sédiment de surface et du biote (P. Viridis, P. erosa,) au travers de deux sites atelier : la baie de Jakarta et la lagune de Segara Anakan (Java, Indonésie).Les méthodes de préparation des échantillon (extraction par solvant puis purification par chromatographie d’adsorption) suivies de l’analyse des extraits par GC/MS/MS ont été développées et qualifiées (linéarité, spécificité, reproductibilité).Les n-alcanes, HAP, PCBs et OCs sont détectés à des teneurs pouvant atteindre respectivement 1935 µg/kgPS, 916 µg/kg PS, 116,49 µg/kg PS, et 16,70 µg/kg PS, dans des sediments et 1739 µg/kg PS des HAPs et 24,79 µg/kg PS des OCs dans le biote. Les hydrocarbures, comme les HAPs sont majoritairement d’origine pétrolière (fuites, transport utilisation) même si la contribution pyrolytique est toujours présente.L’évaluation du risque environnemental a été réalisés pour les HAP, PCBS et et les OCs en utilisant les lignes directrices de la qualité des sédiments (RQS). Ces données peuvent servir de référence de base dans le cadre du programme de gestion intégrée des bassins versants impliquant la biodiversité, l'écologie de l'eau douce, et l'activité économique dans le domaine de cette étude. / Environmental problems can increase due to anthropogenic activities or natural phenomena. Indonesia is an archipelagic country that consists of many islands and coastal regions, where the growth of anthrophogenic and natural activities has exhibited severe environmental degradation in the past few decades. This study aims to explore (both qualitatively and quantitatively) the extent and sources of organic contaminants, i.e., n-alkanes in surface sediments; PAHs, PCBs and OCs in sediments and mussels, P. viridis from Jakarta Bay, North Jakarta, and P. erosa from the Segara Anakan Lagoon. Each protocol was continued with qualitative and quantitative analysis by GC-QQQ(triple-quadropole)/MS. Matrix interferences have been evaluated with proper samples with suitable yield of extraction and analysis. The n-alkanes, PAHs, PCBs and Organochlorin pesticides are detected in the highest levels in sediments, respectively 1935 µg/kg dw, 916 µg/kg dw, 116,49 µg/kg dw, and 16,70 µg/kg dw. In addition, the highest levels of PAHs (1739 µg/kg dw) and OCs levels (24,79 µg/kg dw) were found in biota. The source of hydrocarbons source, such the PAHs were generalelly petroleum source (transport utilization) although the pyrolytic are still present in sediments and biota. Environmental risk assessment from sediment quality guidelines (SQGs) were used to evaluate the probability risk in marine environments. Besides SQGs, sediments and mussels also in regard to the extent of the PAHs, PCBs and OCs (i.e. pp’-DDE) have been compared to other studies conducted at some polluted sites.