Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os foraminíferos de zona entre-marés são amplamente utilizados como na reconstituição paleoambiental holocênica. Entretanto, a despeito dos manguezais, estudos com foraminíferos são relativamente escassos. A estrutura do habitat e seu grau de exposição atuam na distribuição espacial das espécies de zona entre-marés. Em um perfil transversal ao manguezal que margeia a baía de Sepetiba (RJ), foi investigada a influência parâmetros estruturais do habitat e da riqueza na distribuição espacial dos foraminíferos do manguezal. Os parâmetros escolhidos neste estudo foram serapilheira, litologia, matéria orgânica total, microtopografia, zonação botânica, espécies botânicas, altura média das árvores e densidade de árvores. Um testemunho de 144 cm também foi descrito em termos da sua litologia, matéria orgânica total, composição biogênica, incluído foraminíferos. O perfil apresentou textura silte argilosa, matéria orgânica total concentrada por todo manguezal e a serapilheira acumulada principalmente no mangue superior. Os forminíferos (24) ocorreram apenas no manguezal, com predomínio de aglutinantes e presença significativa de formas calcárias. A densidade de testas se concentrou no mangue superior. A. beccarii f. tepida, E. excavatum, A. mexicana, Q. seminulum e T. inflata foram as espécies mais constantes. A diversidade não apresentou variabilidade espacial significativa e foi marcada pela baixa dominância e alta equitabilidade. Notou-se diferença significativa da riqueza de foraminíferos entre habitats expostos e protegidos. A riqueza específica apresentou moderada correlação com a serapilheira e densidade de árvores. A. mexicana e H. wilberti apresentaram moderada correlação com a riqueza. Q. seminulum apresentou significativa correlação com a matéria orgânica total e altura média das árvores. T. inflata apresentou significativa correlação com a riqueza e serapilheira. Em relação ao testemunho, foi possível identificar três paleoambientes de baía restrita: infralitoral, mesolitoral e supralitoral. O manguezal este presente entre o nível 124 62 cm e a planície hipersalina a partir do nível 24 cm. / Intertidal foraminifera are widely used for reconstructing the Holocene environmental. However, despite the mangroves, studies of foraminifera are relatively scarce. The structure of the habitat and its degree of exposure acts in the spatial distribution of intertidal species. In a profile across the mangrove which borders the Bay of Sepetiba (RJ), was investigated the influence of habitat and structural parameters in spatial distribution of foraminifera in the mangrove. The parameters chosen in this study were litter, lithology, total organic matter, topography, botanical zones, botanical species, average tree height and density of trees. A core (144 cm) was also descript in terms of its lithology, total organic matter, biogenic composition, including foraminifera. The profile presented clayey silt texture, total organic matter concentrated around mangrove and litter accumulated mainly in mangrove higher. The foraminifera (24) occurred only in the mangrove, dominated by the agglutinanted species, but with significant presence of calcareous species. The density of tests concentrated in mangrove higher. A. beccarii f. tepida, E. excavatum, A. mexicana, Q. seminulum and T. inflata were more constant. The diversity showed no significant spatial variability, and was marked by low dominance and high evenness. There was a significant difference of the species richness between exposed and protected habitats. The species richness showed moderate correlation with litter and density of trees. A. mexicana and H. wilberti showed moderate correlation with species richness. Q. seminulum showed significant correlation with total organic matter and average height of the trees. T. inflata showed significant correlation with the richness and the litter. In the core, it was possible to identify three paleoenvironments of confined bay: infralitoral, mesolitoral and supralitoral. The mangrove occurred between the level 124cm and 62 cm, and hipersaline flat from the level 24 cm.

O presente estudo integra informações bioestratigráficas e paleoecológicas obtidas através da análise de foraminíferos planctônicos e bentônicos recuperados dos sedimentos provenientes de cinco poços (1-MAS-1, 1-MAS-3A, 1-MAS-4A, 1-MAS-14 e 1-MAS-15) da Bacia de Barreirinhas, perfazendo um total de 127 amostras de calha preparadas e analisadas. Os sedimentos aqui analisados abrangem os andares Albiano superior ao Campaniano superior com registro geológico inserido nos grupos Caju (Albiano - Cenomaniano) e Humberto de Campos (Turoniano - Maastrichtiano). Através dos dados bioestratigráficos obtidos foi possível estabelecer sete biozonas de foraminíferos, de caráter local, com base na última ocorrência do táxon guia (LAD - Last Appereance Datum). O Albiano superior foi definido com base nas biozonas do foraminífero planctônico Ticinella primula Lauterbacher (1963) e foraminíferos bentônicos Lingulogavelinella albiensis Malapris (1965)-Gyroidina bandyi Trujillo (1960); o Cenomaniano inferior foi determinado através das biozonas do foraminífero planctônico Globigerinelloides bentonensis Morrow (1934) e foraminífero bentônico Coronorotalites aptiensis Bettenstaedt (1952); o Cenomaniano superior foi reconhecido através das biozonas do foraminífero planctônico Rotalipora appeninica Renz (1936) e foraminífero bentônico Gavelinella intermedia Berthelin (1880); o Campaniano superior foi determinado com base na biozona do foraminífero planctônico Heterohelix pulchra Brotzen (1936). Após a identificação da microfauna, foi possível reconhecer 108 espécies de foraminíferos pertencentes a cinco subordens: a Subordem Globigerinina, de foraminíferos planctônicos, é representada por 40 espécies e 15 gêneros; os foraminíferos bentônicos são compostos por 68 espécies e 48 gêneros, pertencentes as Subordens Rotaliina, Textulariina, Lagenina e Miliolina. Através da análise da assembléia de foraminíferos, foi possível traçar a CCD (Carbonate Compensation Depth - Profundidade de Compensação do Carbonato) nos poços e separá-los com base na profundidade em: distais (1-MAS-1 e 1-MAS-14) e proximais (1-MAS-3A, 1-MAS-4A e 1-MAS-15). Observou-se que a Bacia de Barreirinhas possui uma tendência geral transgressiva ao longo do Período Cretáceo, caracterizada por meio do influxo sedimentar através de variações climáticas, como o aquecimento global ocorrido neste período. Esta teoria é reforçada pela completa ausência de tecas calcárias, tanto de foraminíferos bentônicos, quanto planctônicos, associada à ocorrência exclusiva de bentônicos aglutinantes e silicosos (Reophax globosus) nos poços distais ao final do Período Cretáceo. Nos poços 1-MAS-3A, 1-MAS-4A e 1-MAS-15, a fauna de foraminíferos identificada apresenta adaptações morfológicas a condições de baixa oxigenação na coluna d'água, características normalmente observadas durante os Eventos Oceânicos Anóxicos (Oceanic Anoxic Event - OEA). Como exemplo destas adaptações morfológicas, foram identificadas três espécies pertencentes ao gênero Schakoina, que possui câmaras alongadas e a espécie Biticinella breggiensis, que possui câmaras bilobadas, sugerindo um aumento na produtividade primária, disponibilidade de nutrientes e paleoambientes depletados em oxigênio. Com base nestas informações foi possível identificar que um Evento Anóxico de caráter local tenha ocorrido durante o Albiano superior, registrado somente nos poços 1-MAS-3A e 1-MAS-4A, enquanto que o Evento Anóxico Global 2 foi registrado no poço 1-MAS-15. / This study integrates biostratigraphic and paleoecological information obtained through of planktonic and benthic foraminifera analysis from sediment recovered from five wells (1-MAS-1, 1-MAS-3A, 1-MAS-4A, 1-MAS-14 and 1-MAS-15) of Barreirinhas Basin, making a total of 127 samples prepared and analyzed. The sediments analyzed here cover the upper Albian to upper Campanian stages with geological record inserted in the Caju (Albian - Cenomanian) and Humberto de Campos (Turonian - Maastrichtian) groups. Through the biostratigraphic data obtained it was possible to establish seven foraminiferal biozones, of local character, based on the last occurrence of taxon guide (LAD - Last Appereance Datum). The upper Albian was defined based on planktonic foraminifera biozones of Ticinella primula Lauterbacher (1963) and benthic foraminifera Lingulogavelinella albiensis Malapris (1965)-Gyroidina Bandy Trujillo (1960); the lower Cenomanian was determined through the planktonic foraminifera biozones of Globigerinelloides bentonensis Morrow (1934) and benthic foraminifera Coronorotalites aptiensis Bettenstaedt (1952); the upper Cenomanian was recognized through the planktonic foraminifera biozones of Rotalipora appeninica Renz (1936) and benthic foraminifera Gavelinella intermedia Berthelin (1880); the upper Campanian was determined based on the planktonic foraminifera biozone Heterohelix pulchra Brotzen (1936). After the identification of microfauna, was possible to recognize 108 species of foraminifera belonging to five suborders: the Suborder Globigerinina, of planktonic foraminifera, is represented by 40 species and 15 genera; the benthic foraminifera are composed of 68 species and 48 genera, belonging to the suborders Rotaliina, Textulariina, Lagenina and Miliolina. Through analysis of foraminifera assemblage it was possible to trace the CCD (Carbonate Compensation Depth) in the wells and separate them based on depth in: distal (1-MAS-1 and 1-MAS-14) and proximal (1-MAS-3A, 1-MAS-4A and 1-MAS-15). It was noted that the Barreirinhas Basin has an overall transgression during the Cretaceous Period, characterized by sedimentary influx through weather changes, like global warming that occurred during this period. This theory is enhanced by the complete absence of calcareous tests, both of benthic as planktonic foraminifera associated with the exclusive occurrence of agglutinating and arenaceous benthic (Reophax globosus) in the distal wells of the end of Cretaceous Period. In the wells 1-MAS-3A, 1-MAS-4A and 1-MAS-15, the foraminifera fauna identified presents morphological adaptations to conditions of low oxygen in the water column, features typically seen during the Oceanic Anoxic Event (OEA's). As examples of these morphological adaptations, was identified three species of the Schakoina genera, which has elongated chambers and Biticinella breggiensis species, which has bilobeted chambers, suggesting an increase in the primary productivity, nutrient availability and paleoenvironments depleted in oxygen. Based on this information it was possible to identify a local character anoxic events occurred during the upper Albian, recorded only in a well 1-MAS-3A and 1-MAS-4A, while the global anoxic event 2 was recorded in a well 1-MAS-15.

Photo-oxidative stress is one of the key factors that can induce bleaching in reef organisms. With the decline of coral reefs and recurrent bleaching events, many studies have focused on understanding the mechanism behind this phenomenon. Two of the hypotheses that explain how the photosynthetic performance of the symbiont is affected and influences bleaching are: (1) disruption of the photosynthetic pathway by direct damage to the photosystem II (PSII), and (2) by inhibition of the Calvin-Benson cycle. In this dissertation I examine different aspects of photosynthetic performance in symbiont-bearing reef organisms and how this is influenced by symbiont loss and changes in photic stress as a result of different levels of irradiance modulated by time of the year (e.g., season) and depth; and take a closer look into primary productivity by symbionts with controlled laboratory experiments. Field experiments during 2012–2013 at Tennessee Reef, FL, assessed the photosynthetic performance of PSII in the diatom-bearing foraminifer, Amphistegina gibbosa, and the anthozoans: Palythoa cariabeorum, Siderastrea siderea, and Montastraea cavernosa. Data collected for the bleaching trends of A. gibbosa revealed that bleaching rates are higher in the summer months than in winter. Photochemical efficiencies of PSII in A. gibbosa, as measured with PAM fluorometry on the day of collection, were more variable in the shallow site (6 m) than in the deeper site (18 m). Also, photochemical efficiencies at the shallow site were lower during the summer months than during winter months. At the 18 m site, photochemical efficiencies did not exhibit a clear seasonal trend. Depth also had an effect on the measured photochemical efficiencies of the anthozoans. Photochemical efficiencies were lower and more variable in colonies at 6 m compared to colonies from 18 m. Although previous studies have reported seasonal effects on the photochemical efficiency of some coral colonies, that trend was not apparent in this study. Photoacclimation and productivity were assessed for A. gibbosa using rapid light curves (RLC) and photosynthesis vs. irradiance curves (P-E). Maximum relative electron transport rate (rETRmax) as described by RLCs was significantly different between A. gibbosa without visual signs of bleaching and those with severe bleaching. Individuals with partial bleaching had a rETRmax that was intermediate between the other two categories. The P-E curves showed a similar trend. In this case individuals that were non- or partly bleached had significantly higher photosynthesis maxima than those with severe bleaching. The onsets of photosynthesis and saturation irradiance were not significantly different among the categories of bleaching analyzed. Results from this dissertation suggest that A. gibbosa has the capability to detect and digest damaged symbionts, that the symbionts even in the deeper chambers react in a similar way to irradiance, but that in severe cases of bleaching the symbionts may not produce enough energy to sustain the requirements of the host, even in non-stressful conditions.

The development of an accurate and precise geochronology is imperative to understanding archives containing information about Earth’s past. Unable to date all intervals of an archive, researchers use methods of interpolation to approximate age between dates. Sections of the radiocarbon calibration curve can induce larger chronological uncertainty independent of instrumental precision, meaning even a precise date may carry inflated error in its calibration to a calendar age. Methods of interpolation range from step-wise linear regression to, most recently, Bayesian statistical models. These employ prior knowledge of accumulation rate to provide a more informed interpolation between neighboring dates. This study uses a Bayesian statistical accumulation model to inform non-sequential dating of a sediment core using a high-throughput gas-accepting accelerator mass spectrometer. Chronological uncertainty was iteratively improved but approached an asymptote due to a blend of calibration uncertainty, instrument error and sampling frequency. This novel method resulted in a superior chronology when compared to a traditional sediment core chronology with fewer, but more precise, dates from the same location. The high-resolution chronology was constructed for a gravity core from the Pigmy Basin with an overall 95% confidence age range of 360 years, unmatched by the previously established chronology of 460 years. This research reveals that a larger number of low-precision dates requires less interpolation, resulting in a more robust chronology than one based on fewer high-precision measurements necessitating a higher degree of age interpolation.

Trois carottes de 5 à 6 m de profondeur ont été prélevées tout au long de l’oued El Akarit (Golfe de Gabès, Sud tunisien) : deux sur la rive Nord et une à l’embouchure. L’étude sédimentologique (granulométrie), minéralogique (minéraux argileux) et micropaléontologique (ostracodes, foraminifères et charophytes) et leur étude quantitative et qualitative ainsi que le calcul des indices de diversités de Shannon et d’équitabilité nous a permis de reconstituer l’évolution des paléo-environnements succédés depuis le Pléistocène dans la région El Akarit. La carotte à l’embouchure de l’oued El Akarit (carotte AK1), nous a permis de dater avec précision les dépôts étudiés et de reconstituer la chronologie des évènements ayant contrôlé la sédimentation. La phase pléistocène (>45000 ans B.P), milieu continental estuarien évoluant vers unevaste lagune très ouverte à la mer lors de la transgression marine pléistocène (MIS5e), par la suite l’installation d’un cordon sableux isole cette lagune de l’environnement marin. Les dépôts holocènes inférieurs et moyens sont absents dans l’embouchure de l’oued El Akarit à cause d’une émersion et non dépôt et/ou d’une érosion des dépôts. La phase Holocène supérieur (derniers 3000 ans B.P), se caractérise par la succession de trois épisodes d’évènements extrêmes (crues et tempêtes). A 1 et 2 km du rivage actuel (carotte AK2 et AK3 respectivement), les dépôts généralementcontinentaux montrent des intercalations des dépôts marins et des niveaux à galets enregistrant des évènements extrêmes. Les dépôts de ̴ 8000ans B.P de la poche à « Cardium » à 9 m d’altitude de la mer actuelle, montrent une influence marine (abondance des foraminifères planctoniques), il s’agit évidemment d’un évènement extrême exceptionnel qui provoquerait le transport des foraminifères planctoniques à l’intérieur de la lagune El Akarit. / Three cores varying from 5 to 6 m of depth were taken throughout in the El Akarit River (Gulf of Gabes, south of Tunisia): two on the left river bank and the last at the mouth. The study of the sedimentology (particle size), mineral (clay minerals) and micropaleontology (quantitative and qualitative study of ostracods, foraminifera, charophytes and the calculation of the Shannon / equitability diversity index) deposits content allowed us to reconstruct the paleoenvironments evolution since the Pleistocene in this region. The mouth core (AK1), permitted us to date precisely the studied deposits and reconstruct the events chronology controlling the sedimentation. The Pleistocene phase (> 45 000 years BP) shows a continental estuarine environment evolving toward a vast open lagoon during the Pleistocene marine transgression (MIS5e). Then, the formation of a sand bar isolates the lagoon from the marine environment. The lower and middle Holocene deposits are absent in the mouth deposits. This could be interpreted by the emersion of the zone or by the erosion of deposits. The late Holocene (last 3000 years B.P) phase is characterized by the succession of three extreme events (floods and storms) episodes. At 1 and 2 km from the current shoreline (AK2 and AK3 cores respectively), the continental deposits show an intercalation of marine deposits and pebble levels suggestive of an extreme events occurrence. The existence of the 8000 yr BP deposits "Cardium pocket” at 9 m of the current sea, show a marine influence (planktonic foraminifera abundance). It is apparently an exceptional event that would cause extreme transport of planktonic foraminifera inside the El Akarit lagoon

The Neogene history of Caribbean deep-sea benthic foraminifera was investigated by calculating changes in paleoproductivity, diversity and paleobiogeography ~26 to 2 Ma, which includes the progressive closure of the Central American Seaway. Three hypotheses were tested: (1) Paleoproductivity values prior to closure of the Central American Seaway are similar in both the Caribbean and equatorial Pacific and then diverge by the time of early shoaling events; (2) Diversity values of benthic foraminifera prior to the closure of the Central American Seaway were similar in the Caribbean and EEP, and had changed by the time of early shoaling; and (3) during the Miocene and into the Pleistocene, the progressive constriction of the CAS affected deep-sea benthic foraminiferal assemblages by increasing their dissimilarity between the Caribbean and equatorial Eastern Pacific. These hypotheses were tested with 104 samples from five Caribbean and EEP deep-sea cores by calculating paleoproductivity with multiple proxies, determining diversity indices and calculating biogeographic similarity coefficients. The data supported the first two hypotheses: The greatest change in paleoproductivity occurred at ~8 Ma during seaway constriction, when values diverged between the Caribbean and EEP. After complete seaway closure at ~4 Ma, the Caribbean became oligotrophic, noted by a decrease in high-organic flux species, and an increase in Nuttalides umbonifera, an indicator species. The largest changes in species-level diversity occurred with the barrier to deep-water flow at ~12 Ma, and Caribbean diversity increased at ~8 Ma with seaway constriction. However, the third hypothesis was rejected: Increases in assemblage similarity actually occurred during most major paleoceanographic events, with the only decrease in Caribbean-EEP similarity occurring at ~12 Ma, coincident with a drop in diversity and emplacement of the Panama isthmian sill. Thus, the barrier to deep-water flow at ~12 Ma affected the composition of tropical American benthic foraminifera more than the largest change in paleoproductivity at ~8 Ma, or closure of the Central American Seaway at ~4 Ma.

Efforts that are underway to rehabilitate the Florida Bay ecosystem to a more natural state are best guided by a comprehensive understanding of the natural versus human-induced variability that has existed within the ecosystem. Benthic foraminifera, which are well-known paleoenvironmental indicators, were identified in 203 sediment samples from six sediment cores taken from Florida Bay, and analyzed to understand the environmental variability through anthropogenically unaltered and altered periods. In this research, taxa serving as indicators of (1) seagrass abundance (which is correlated with water quality), (2) salinity, and (3) general habitat change, were studied in detail over the past 120 years, and more generally over the past ~4000 years. Historical seagrass abundance was reconstructed with the proportions of species that prefer living attached to seagrass blades over other substrates. Historical salinity trends were determined by analyzing brackish versus marine faunas, which were defined based on species’ salinity preferences. Statistical methods including cluster analysis, discriminant analysis, analysis of variance and Fisher’s α were used to analyze trends in the data. The changes in seagrass abundance and salinity over the last ~120 years are attributed to anthropogenic activities such as construction of the Flagler Railroad from the mainland to the Florida Keys, the Tamiami Trail that stretches from the east to west coast, and canals and levees in south Florida, as well as natural events such as droughts and increased rainfall from hurricanes. Longer term changes (over ~4000 years) in seagrass abundance and salinity are mostly related to sea level changes. Since seawater entered the Florida Bay area around ~4000 years ago, only one probable sea level drop occurring around ~3000 years was identified.

This study investigates the use of larger foraminifera in determining the biostratigraphy of the Avon Park Formation and the Ocala Limestone in central Florida. Sedimentary rocks of the Avon Park Formation are the oldest exposed deposits in the state of Florida, and together with the Ocala Limestone comprise a part of the confining unit of the Floridan Aquifer, a major source of Florida’s water supply. Material from the ROMP 29A core collected by the U. S. Geological Survey was evaluated and compared to previous studies of the biostratigraphy of the formations. The larger foraminifera of the Avon Park Formation were examined in thin section, and those of the Ocala Limestone were free specimens. The larger foraminifera from both units were described and identified, and the biostratigraphy determined. The morphological features of the larger foraminifera of the Ocala Limestone were measured and analyzed at various depths within the ROMP 29A core. The Avon Park Formation contains predominantly the shallow-water, conical foraminifera Fallotella cookei, Fallotella floridana, Pseudochrysalidina floridana, Coleiconus christianaensis, Coleiconus sp. A, Coskinolina sp. A, Coskinolina sp. B, Fallotella sp. A, Fallotella sp. B, Fabularia vaughani and larger miliolids. The Ocala Limestone contains a different, deeper water assemblage that included the larger foraminifera Heterostegina ocalana, Lepidocyclina ocalana varieties, Lepidocyclina chaperi, Lepidocyclina pustulosa, Nummulites willcoxi, Nummulites striatoreticulatus, Nummulites floridensis and Pseudophragmina spp. A, B, and C. The age of the Avon Park Formation was corroborated by the occurrence of the biomarker echinoid Neolaganum dalli as Eocene, and the Ocala Limestone also contained Eocene larger foraminifera with Eocene to possibly Oligocene calcareous nannofossils. The distribution of the larger foraminifera of the Avon Park Formation was correlated with the subtidal and peritidal zones of the continental shelf. Analyses of variance showed that the changes in measurements of the morphology in Heterostegina ocalana, Lepidocyclina spp. and Nummulites spp. were correlated with change in the depositional environments.

Thesis is focused on foraminifera from classical Březno section. It describes the basic charakteristics of foraminifera, Czech Cretaceous Basin, Březno section near Louny and history of research of Cretaceous foraminifera in Czech Republic. Taxonomically studied planktonic foraminifera species are from family Heterohelicidae Cushman, 1927, and benthos species are from family Lagenidae Reuss, 1862, Nodosariidae Ehrenberg, 1838, and Vaginulinidae Reuss, 1860. Key words: Foraminifera, Cretaceous, Březno near Louny, Heterohelicidae, Lagenidae, Nodosariidae, Vaginulinidae

The Paleocene and early Eocene (~66–40 Ma) is characterised by a number of transient warming events, also named hyperthermals. A more recent candidate for a hyperthermal of Paleocene age is the Latest Danian Event (LDE, ~62.2 Ma). So far, the LDE was only poorly explored in few deep-sea records and Tethyan shelf settings. Planktic data characterizing the surface ocean were almost completely missing. In this thesis, it was studied whether the LDE satisfies the requirements for a hyperthermal and the impact on the planktic foraminfera fauna. Samples from three late Danian deep-sea cores (ODP Sites 1210 and 1262, IODP Site U1407) and one Tethyan shelf section (Qreiya 3, Egypt) were investigated in rather high resolution, which, for the first time, allowed to unravel the impact of the LDE, the evolution of the ocean structure and planktic foraminiferal species abundances on an almost global scale. δ18O paleothermometry revealed a temperature rise of 2–4°C affecting the entire water column in all three depth habitats (sea floor, subsurface and surface ocean) and a contemporary negative carbon isotope excusion of 0.6–0.9 ‰ indicates carbon cycle perturbations. Changes in the planktic foraminiferal assemblages indicate a global biotic response to the LDE.