Crassostrea virginica, the eastern oyster, is a native keystone species that inhabits many coastal and estuarine ecosystems along the Atlantic seaboard. Introduction of the eastern oyster into estuarine areas with limited current populations is gaining popularity as a pro-active approach to improve estuarine water quality. In November 2014 and April 2015, a total of five pilot oyster reef treatments were deployed in Brevard County: bagged adult oysters (grown by community members under their docks through oyster gardening) collected in fall 2014 and spring 2015, bagged clean shell, oyster restoration mats, and empty plots (control). Locations of deployment included a Merritt Island impoundment (Marsh Harbor), Nicol Park (Port St. John), and Scout Island (Melbourne Beach). Prior to deployment, we collected morphometric data (shell length, weight) on all gardened oysters. Abiotic factors including salinity, air and water temperature, and wind speed were collected monthly. During quarterly sampling at each site, morphometric data were collected for all live oysters, surviving and newly recruited. Results show survival of gardened oysters and natural recruitment differed by and depended greatly on the within-site location of each reef. In areas with no recruitment and limited gardened oyster survival, regular deployment of gardened oysters is needed for long term success. In areas with natural recruitment, bagged, clean shell or oyster restoration mats are most successful. Future restoration sites should be tested prior to any large-scale oyster deployments.

No description available.

Mangrove stands and oyster reefs are two common coastal habitats in the Indian River Lagoon. Each habitat provides diverse ecosystem services, including carbon sequestration and carbon storage. A decrease in freeze events and an increase in sea levels are leading to mangrove habitat expansion, including encroachment onto live oyster reefs in the IRL’s northernmost portion, Mosquito Lagoon. This study investigates how the encroachment of black mangroves (Avicennia germinans) and red mangroves (Rhizophora mangle) on eastern oyster reefs (Crassostrea virginica) impacts the abundance and stability of soil carbon relative to each habitat alone. Soil and sediment samples (0-10cm) were collected from three locations in Mosquito Lagoon, each containing a mangrove-only, oyster-only, and mangrove-encroached oyster reef habitat. Total and active carbon were quantified, and stable carbon was determined through physical and density fractionation that isolates persistent mineral-associated organic matter (MAOM). Results showed total, active, and MAOM-carbon averaged 2-3 times greater in mangroves than oyster reefs, while mangrove-encroached oyster reefs were intermediate in concentration. However, mangrove-oyster soils have the highest proportion of the total carbon pool protected as MAOM (54.9%), compared to each habitat alone (mangrove-only, 35.3%, oyster-only, 30.3%). This research is the first to provide data on blue carbon storage in areas where mangroves encroach on oyster reefs, including differentiating total carbon based on its stability in the soil.

A coastal lagoon is a landform that is influenced by natural processes and human activities. All human activities at the upstream, particularly agriculture and cultivation bring soil, waste, and other materials to the downstream area through the river drains into the lagoon. Even though its position is inland of water bodies, the lagoon is still affected by waves and winds from the sea. Additionally, coastal lagoon will be the depository place for sedimentation from the upland area. Segara Anakan (SA), which is located in Indonesia, is an example of a coastal lagoon area, which has a unique biophysical characteristic. The region has a great natural ability to ensure the sustainability of the interrelationships between terrestrial, estuarine and marine ecosystems in harmony and balance as a habitat for flora and fauna. The region is an area of migration of various types of protected animals and it is a place of breeding for diverse species of the shrimp and fish, which have a highly economical value. Segara Anakan lagoon (SAL), currently experiencing acceleration narrowed on its area due to a very intensive sedimentation from the mainland. The research aims to answer the question of how ecological dynamic occurs in the SAL area due to sedimentation. Achieving the objectives of this study required examining the morphology and land use changes with multitemporal remote sensing approaches. While, to assess the role of community participation and planning management strategies is using qualitative descriptive methods and SWOT analyze. The using of multitemporal remote sensing Landsat images is possible to analyze the morphological and land use changes with different time and sensors. These Landsat has image accuracy about 92.66%. It can be used for image interpretations resulting 13 classes of land use. The morphodynamics of SAL indicated by the changes of area of lagoon and accreted land and also the distance of coastlines during the periods 1979-2013. In addition, the land use or land cover also changes during that time. The bigger portions of land use changes are in the tropical and mangrove\''s forests. There are distinctive forms of participation in conservation efforts. The upstream community involvement in conservation tends to be different participating in the way of ideas, money, materials, properties, skills and expertise or social activities. In addition, the community at downstream area has a sufficiently high level of participation in environmental conservation. There are also strong relationships between the level of education and level of income and basic knowledge in conservation with the participation of SA conservation. The ecological dynamics of the SAL area are described with a historical time line. It is divided into three time periods: the 1970s - 1980s, the 1990s and from 2000 onwards. Each of these has occurrences that can lead to changes in the environment. The implementation of appropriate conservation technique can reduce the sedimentation rate. Hence, the synergic coordination measures between upstream and downstream regions are necessary in the future. Increasing community awareness and participation in the conservation by improving educational sector, providing information, and applying sustainable development land use are the ways to match human activities with the temporal and spatial dynamics of the coastal resources.

L'étude de la relation entre les variations d'abondance du phytoplancton et les facteurs environnementaux (naturels ou anthropiques) dans les zones saumâtres peu profondes est essentielle à la compréhension et à la gestion de cet écosystème complexe. Les relations existant entre les variables physico-chimiques (température, salinité et les nutriments) et les assemblages de phytoplancton de l'étang de Berre ont été analysées à partir d'un suivi écologique mensuel de 16 années (1994-2010). A l'aide des données recueillies par cette étude à long terme, des questions en relation avec la gestion de ce milieu ont été abordées grâce à l'application d'analyses statistiques et à la représentation originale des données. Depuis 2004, la nouvelle politique de relargage d'eau douce a provoqué de forts changements dans la salinité globale de la lagune : une diminution de la stratification et une raréfaction des phénomènes d'anoxie dans sa partie la plus profonde. Un changement dans la structure de la communauté phytoplanctonique a également été observé en association avec l'évolution des conditions environnementales. Une augmentation de la richesse spécifique phytoplanctonique, et plus précisément, l'émergence d'espèces à affinité marine a permis de mettre en évidence la première étape d'une marinisation de la lagune. Ces résultats soulignent l'impact significatif d'un nouvelle politique de gestion de cette zone côtière particulière. Nous nous sommes ensuite intéressés à la dynamique du phytoplancton à l'échelle de la journée reflet des variations rapides de l'environnement. / The study of the relationship between variations in phytoplankton abundance and environmental forces (natural or anthropogenic) in shallow brackish areas is essential to both understanding and managing this complex ecosystem. Over a 16 year (1994-2011) monthly monitoring program the relationships between physicochemical variables (temperature, salinity and nutrients) and phytoplankton assemblages of the Berre Lagoon were analyzed. Using data collected from this long-term study, we have addressed environmental management issues through the application of advanced statistical analyses and original data displays. These analyses and data displays can readily be applied to other data sets related to the environment, with the aim of informing both researcher and practitioner. Since 2004, a new policy for freshwater discharge has induced strong changes in the global salinity of the lagoon : a weakened stratification and a rarefaction of anoxia phenomena in its deepest part. A shift in the structure of the phytoplankton community has been observed in association with changes in environmental conditions. An increase of phytoplanktonic species richness, and more precisely, the emergence of species with marine affinity highlights the first step of a marinization of the lagoon. The results underline the significant impact of a new management policy in this specific coastal zone. We then focused on the response of phytoplankton to quick environmental variations. An original approach for automated high frequency analysis of phytoplankton was adopted with the use of an autonomous flow cytometer (CytoSense).

Depuis sa première signalisation en 2005, le cténophore Mnemiopsis leidyi a été régulièrement observé dans l'Étang de Berre et a profité d'un écosystème planctonique perturbé. En effet, la régulation des apports en eau douce provenant de la centrale hydroélectrique EDF de Saint-Chamas (2006) a entraîné une augmentation de la salinité moyenne de la lagune, ainsi qu'une diversification et une « marinisation » des communautés planctoniques de la lagune. Leurs caractéristiques et la dynamique de la population de M. leidyi ont été étudiées au cours d'un suivi in situ réalisé en 2010-11. Les données obtenues lors de ce suivi, associées à une étude de son métabolisme (i.e. ingestion, respiration, excrétion et croissance), ont permis d'identifier les principaux facteurs contrôlant sa population (i.e. température, salinité, concentration et nature des proies). Son cycle de vie est étroitement lié à la température, les larves cyddipides apparaissant en hiver, suivies par les stades de transition en hiver/printemps et par les adultes du printemps à l'automne. Les conditions saumâtre et eutrophe semblent contribuer à sa présence dans la lagune, avec une salinité optimale pour son développement et une forte concentration en proies (i.e. zooplancton pour les adultes). En raison de la sélection active de proies (i.e. nauplii de copépodes et copépodites) et l'absence de seuil de satiété, M. leidyi a un impact important sur les populations de copépodes entraînant la chute drastique de leur abondance suite à ses proliférations. De nouvelles modifications des conditions hydrologiques (i.e. évolution vers une lagune marine) pourraient continuer à transformer le fonctionnement de la lagune. / The ctenophore Mnemiopsis leidyi has established a sustainable population in the Berre Lagoon since its first observation in 2005. This invasive species took advantage of a plankton ecosystem disturbed particularly by successive modifications of the hydrohalin conditions of the lagoon. Indeed, regulation of the freshwater inputs through the hydroelectric power plant of Saint-Chamas (2006) leads to an increase of the mean salinity, resulting in a more diversified and a more marine plankton community. Characteristics of the plankton ecosystem and population dynamics of M. leidyi was studied during an in situ survey in 2010-11. Metabolism (ingestion, respiration, excretion and growth) of the ctenophore adult and transition stages were studied in controlled conditions. Temperature influences the life cycle of M. leidyi with cyddipid larvae observed in winter, then transitional stages in winter/spring and adults from spring to autumn. The ctenophore seems to prefer brackish and eutrophic environments linked with its optimal salinity conditions (between 10 and 30) and its need for an important prey concentration (copepods nauplii and copepodites). The active selectivity of prey and the lack of a satiety level can largely explain the drop in copepod abundance following M. leidyi proliferations. New hydrological modifications (evolution towards a marine lagoon) will certainly continue to transform in the future the functioning of the Berre Lagoon.

Le paysage littoral de la basse vallée de l’Aude est composé d’une mosaïque de milieux laguno-deltaïques mobiles à l’échelle des derniers millénaires. Du fait de cette mobilité et de l’ancienneté de l’occupation humaine, continue depuis le Néolithique, la compréhension des dynamiques environnementales passées constitue une problématique incontournable de la recherche archéologique narbonnaise. Le travail que nous présentons vise à identifier et expliquer les transformations de ce paysage fluvio-lagunaire à l’Holocène, à partir de l’analyse sédimentologique et micropaléontologique des enregistrements sédimentaires datés au radiocarbone. Dans un premier temps, une étude de la répartition spatiale actuelle des ostracodes des lagunes et embouchures fluviales modernes est proposée en vue d’utiliser cette microfaune comme bioindicateur privilégié des conditions environnementales passées dans la zone d’étude. Elle repose sur le prélèvement d’une soixantaine d’échantillons de sédiments de surface provenant de différents complexes paraliques de Méditerranée nord-occidentale. Les assemblages d’ostracodes actuels permettent de caractériser différents stades d’isolement des bassins, des lagunes complètement fermées jusqu’aux baies largement ouvertes sur la mer, ainsi que la variabilité intra-lagunaire des milieux en relation avec la proximité des embouchures et des graus. La base de données présentée peut être utilisée, à titre comparatif, pour reconstituer les dynamiques géomorphologiques littorales holocènes, telles que la mobilité deltaïque et l’évolution des systèmes barrières-lagunes, dans le golfe du Lion. Dans un second temps, l’étude des enregistrements sédimentaires a permis d’appréhender l’évolution du littoral narbonnais à l’Holocène. Elle repose sur neuf sondages carottés répartis sur les deux branches deltaïques, méridionale et orientale, de l’Aude. Les résultats obtenus permettent de proposer un scénario paléogéographique reconstituant la dynamique des environnements de la basse vallée depuis 9500 ans cal. BP, en même temps qu’ils renseignent le contexte local de la remontée du niveau marin holocène dans l’intervalle 9500-6000 ans cal. BP. Plusieurs problématiques sous-jacentes à l’évolution des paléoenvironnements littoraux narbonnais sont discutées. Elles concernent les modalités de la transgression holocène dans les lagunes du golfe du Lion, l’enregistrement d’un événement marin extrême en fond de ria vers 5200-5000 ans cal. BP, et le rythme de progradation accéléré du delta de l’Aude durant le dernier millénaire. L’identification de deux périodes d’enrichissement en plomb cohérentes avec les principaux pics d’exploitation minière connus en Languedoc à la charnière du changement d’ère et au début du Moyen-âge classique suggère un enregistrement de la fluctuation historique des activités métallurgiques. / The present day Aude valley’s coastal landscape is the result of unstable lagoonal and deltaic environments during the last millennia. The understanding of past environmental dynamics is a key issue of the local ar-chaeological research, because since the Neolithic period human beings have settled in this area. This work aims to identify and explain the fluvio-lagoonal landscape’s evolution in the Narbonne region during the Holocene by using sedimentology, micropalaeontology and radiocarbon sediment datations. First, we analysed the present ostracods spatial distribution in modern lagoons and river mouths in order to use this microfauna as a bioindicator of past environmental conditions in the study area. Various aquatic envi-ronments (60) from the NW Mediterranean coastline were studied. The present ostracod assemblages characterize different stages of isolation, from completely closed lagoons to widely open marine bays, as well as intra-lagoonal environmental variability in relation to the inlets and river mouth proximities. The proposed database can be used to reconstruct coastal geomorphologies and dynamics, such as the holocene evolution of delta and barrier-lagoon systems in the Gulf of Lion. Second, sedimentary recording studies have been used to analyse the Narbonne’s coastal evolution. This study is based on nine cores distributed over the southern and eastern deltaic branches of the Aude river. With theses results, it is possible to propose a palaeogeographic scenario associated with the environmental dynamics of the lower valley since 9500 years cal. BP. This same data informs us about the local context of the Holocene sea level rise during the 9500-6000 years cal. BP. Several issues are discussed such as : the Holocene’s transgressions of the Gulf of Lion’s lagoons, the extreme marine event near the bay head delta around 5200-5000 years cal. BP, and the Aude delta’s rapid progradation during the last millennium. Additionally, we identified two periods of lead enrichment; which are consistent with the major mining peaks known in Languedoc (beginning of the first century AD - beginning of the classical Middle ages) and suggest a record of fluctuating metallurgical activity.

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.

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.

Este trabalho teve como objetivo estudar a bioconcentração de elementos-traço no músculo e a presença de micronúcleos nos eritrócitos de Cathorops spixii, coletados no Complexo Estuarino-Lagunar de Cananéia-Iguape, nos setores norte e sul, no verão e inverno de 2009, verificando a influência sazonal e antrópica em cada área. As análises dos elementos traços foram realizadas por Ativação Neutrônica e Espectrometria de Absorção Atômica. Em geral, os peixes apresentaram níveis seguros para consumo humano, exceto para o As, sobretudo nos peixes capturados em Cananéia. Recomenda-se a revisão dos índices de As em relação aos produtos marinhos e mais estudos da relação entre salinidade e bioacumulação deste elemento. Pb e Hg apresentaram maiores concentrações nos peixes de Iguape, independentemente da época do ano, enquanto que As e Cr foram mais elevados em Cananéia. As variações sazonais, nas duas regiões, mostraram que o Hg, Cd e Co apresentaram maiores concentrações no verão, enquanto que o As e o Cr foram maiores no inverno. A expressão de micronúcleo foi baixa, sendo ligeiramente maior na região norte, local mais exposto aos contaminantes devido ao aporte de água do Rio Ribeira de Iguape por meio do canal do Valo Grande, que trás consigo resíduos dos municípios localizados no vale do Ribeira. C. spixii mostrou ser um bom biomonitor ambiental, com potencial para integrar programas de monitoramento em ambientes costeiros e estuarinos em nível nacional. / The aim of this work was study the bioaccumulation of trace elements in the muscle and the presence of micronuclei in the erythrocytes of Cathorops spixii, collected in the Cananéia-Iguape Estuarine-Lagoon Complex, in the sectors north and south, in the summer and winter of 2009, in order to verify the anthropogenic and seasonal influences in each area. Trace elements were analyzed by Neutronic Activation and Atomic Absorption Spectrometry techniques. In general, the fishes had levels safe for human consumption, except for As, especially in fish caught in Cananéia. It is recommended the review of the legislation besides the study of the relationship between salinity and bioaccumulation of this element. Pb and Hg showed higher concentrations in the fishes from Iguape, regardless of the season, while As and Cr were higher in those captured in Cananéia. Seasonal variations in both regions showed higher concentrations of Hg, Cd and Co in the summer, while As and Cr were higher in the winter. The expression micronuclei was low, being slightly higher in the northern region, the most exposed to the contaminants due to the inflow of water from Ribeira de Iguape River, through the Valo Grande Channel, which brings with it waste of municipalities located in the Ribeira Valley. C. spixii proved to be a good environmental biomonitor with potential to integrate monitoring programs in coastal and estuarine environments at the national level.