This paper deals with approaches toward the conservation of archaeological heritage among different people and different institutions in Samoa. This is compared with approaches toward ecology and preservation of the environment to find out if there are similarities and/or differences. Moreover the opinions on how the public perceive the material heritage is compared with a survey of the public itself and their ideas concerning archaeology. The investigation was carried out by conducting interviews with people working within different institutions, NGO’s and schools as well as representatives from the general population i.e. people without education in conservation and cultural heritage. Possibilities of co-conserving the cultural and ecological values are also examined, as is the relation between culture and a natural feature - the mangroves. / Uppsatsen behandlar åsikter och attityder hos allmänheten och olika institutioner på Samoa gällandebevarandet av det arkeologiska kulturarvet. Detta jämförs med en likande studie gällande bevarandetav miljömässiga och ekologiska värden på Samoa för att se om det finns likheter och skillnader. Studieninkluderar också en undersökning av hur allmänheten ser på det materiella kulturarvet och derasförhållande till och kundkap om arkeologi. Undersökningarna gjordes genom ett intervjuprojekt där desom intervjuades representerade både institutioner, organisationer, skolor och allmänheten, densistnämnda gruppen hade ingen formell kunskap om kulturarvet och dess hantering. Inom ramen förstudien undersöktes också möjligheterna för att samarbeta när det gäller hanteringen och bevarandetav kulturella och ekologiska värden t.ex. gällande mangroveområden.

MOREIRA, Camila Campos Lopes. Valores de referência de qualidade para metais pesados em solos de mangue do Estado do Ceará: subsídios para gestão da zona costeira. 2014. 164 f. Tese (Doutorado em geografia)- Universidade Federal do Ceará, Fortaleza-CE, 2014. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-10T19:11:47Z No. of bitstreams: 1 2014_tese_cclmoreira.pdf: 5894644 bytes, checksum: b9a9dd0cb4f75276be42b6f65a25c89f (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-06-13T23:11:06Z (GMT) No. of bitstreams: 1 2014_tese_cclmoreira.pdf: 5894644 bytes, checksum: b9a9dd0cb4f75276be42b6f65a25c89f (MD5) / Made available in DSpace on 2016-06-13T23:11:06Z (GMT). No. of bitstreams: 1 2014_tese_cclmoreira.pdf: 5894644 bytes, checksum: b9a9dd0cb4f75276be42b6f65a25c89f (MD5) Previous issue date: 2014 / Currently, activities related to urbanization and industrialization have contributed to increased concentrations of heavy metals in different types of soil. These elements have significant toxicity and can accumulate in the environment, configuring serious risk to human health and ecosystems in general. Thus, there is an increasing concern among countries in adopting an efficient environmental policy and, thus, the determination of natural concentration (background levels) of metals in soils and the consequent establishment of Quality Reference Values (QRV) are reality in some countries, including Brazil. However, there is a lack of studies like these related to soils under mangrove forests in the country, where these areas play very important roles and services in the environment. In this context, the contamination of mangrove soils by heavy metals is one of the major environmental issues today and may even compromise the estuaries throughout its length. Thus, a study was carried out in mangrove soils of the State of Ceará aiming their classification and characterization, beyond the determination of natural levels of metals in these soils and the consequent proposition of their QRV. For this, physical, chemical and mineralogical analyzes were realized, beyond the metals extraction by methods of semitotal digestion (EPA 3051A and aqua regia) and the determination of QRV was performed in accordance with the resolution 420/2009 of CONAMA. The results indicated that the semiarid climate preponderant in this region explains the behavior of the main attributes of these soils (ex: EC, TOC, mineral composition). It was also found that the levels of metals in these soils are influenced by the intensity of anthropogenic interference in the coastal environments, given that mangrove soils of Ceará River estuary, inserted into urban context and subjected to environmental stresses, showed the highest enrichment factors of metals. On the other hand, it was observed that the distribution of these elements in this environment is also regulated by interactions between the metals themselves and with attributes as clay and Fe and Mn oxides. Furthermore, the aqua regia digestion was efficient in extracting metals in these soils, while EPA 3051A, indicated by CONAMA for soil quality assessments, underestimated the available levels of metals in the analyzed soils. Given the above, the natural levels of metals determined in this study can serve as a basis for defining QRV for mangrove soils of the State of Ceará, assisting the environmental agency in the formulation of a specific legislation for monitoring mangrove areas in the State, thus setting a new perspective for the management of estuarine environments. / Nos dias de hoje, atividades relacionadas à urbanização e à industrialização têm contribuído para o aumento das concentrações de metais pesados nos diversos tipos de solo. Tais elementos apresentam relevante toxicidade e podem se acumular no ambiente, configurando sério risco à saúde humana e dos ecossistemas em geral. Nesse cenário, percebe-se uma preocupação crescente dos países em adotar uma política ambiental eficiente e, dessa forma, a determinação da concentração natural (níveis de background) de metais nos solos e o estabelecimento de valores de referência de qualidade (VRQs) já são realidade em alguns países, inclusive no Brasil. Entretanto, percebe-se a escassez de estudos dessa natureza que contemplem os solos sob florestas de mangue no país, onde tais áreas são bastante expressivas e desempenham importantes funções e serviços no ambiente. Nesse contexto, a contaminação dos solos de mangue por metais pesados é uma das grandes questões ambientais da atualidade, podendo, inclusive, comprometer os estuários em toda a sua extensão. Assim, foi realizado um estudo em solos de mangue do Estado do Ceará visando a classificação e caracterização dos mesmos, além da determinação dos teores naturais de metais e a consequente proposição de seus VRQs. Para isso, foram realizadas análises físicas, químicas e mineralógicas, extração dos metais por métodos de digestão semitotal (EPA 3051A e água régia) e a determinação dos VRQs foi realizada de acordo com o disposto na resolução n° 420/2009 do CONAMA. Os resultados obtidos indicaram que o clima predominantemente semiárido da região explica o comportamento dos principais atributos desses solos (ex: CE, COT, constituição mineralógica). Verificou-se ainda que os teores de metais nos solos em questão são influenciados pela intensidade da interferência antropogênica nos ambientes costeiros, tendo em vista que os solos de mangue do estuário do rio Ceará, inserido em contexto urbano e submetido a diversos tipos de tensões ambientais, apresentaram os maiores fatores de enriquecimento de metais. Por outro lado, observou-se que a distribuição de tais elementos nesses solos é também regida por interações entre os próprios metais e dos mesmos com atributos como a fração argila e os óxidos de Fe e Mn. Além disso, a digestão por água régia mostrou-se eficiente na extração de metais nesses solos, enquanto o EPA 3051A, indicado pelo CONAMA para avaliações de qualidade dos solos, subestimou os teores dos metais disponíveis nos mesmos. Diante do exposto, os teores naturais dos metais determinados no presente estudo podem servir de base para a definição de VRQs para os solos de mangue do Estado do Ceará, auxiliando o órgão ambiental responsável na formulação de uma legislação específica para o monitoramento das áreas de manguezal do Estado, configurando, portanto, uma nova perspectiva para a gestão dos ambientes estuarinos.

Made available in DSpace on 2014-06-11T19:27:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-06-10Bitstream added on 2014-06-13T18:31:33Z : No. of bitstreams: 1 pinto_ab_me_rcla.pdf: 596619 bytes, checksum: d49075f107bc579ef9e1e0a6e9af23bc (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os ecossistemas costeiros são considerados de grande importância sócio-econômica, política e cultural, pois possuem alta produtividade que suporta uma ampla gama de atividades econômicas e de lazer. Possuem elevado valor paisagístico, atraindo inúmeros habitantes e, assim, contribuem ao desenvolvimento das cidades litorâneas. Além disso, oferecem suporte às comunidades biológicas com manutenção de muitas espécies residentes ou que utilizam a zona costeira como berçário para reprodução, beneficiando a biodiversidade como um todo. Sendo uma região que sofre grande pressão antrópica, a Zona Costeira está sujeita a inúmeros impactos causados por atividades humanas, tais como as portuárias, industriais e de exploração de petróleo. Essas geram impactos por lançarem diversos poluentes, entre eles os hidrocarbonetos e metais que podem ter efeito deletério na biota local. No ambiente marinho, o compartimento mais afetado em relação a essa contaminação é o sedimento em função dos derivados de petróleo que atingem as águas costeiras possuírem maior densidade, nele se depositando. Atualmente existe uma grande preocupação com os impactos gerados por atividades antrópicas em ecossistemas litorâneos e muitos estudos têm sido feitos em busca de alternativas para avaliar e remediar tais impactos. Uma delas consiste no uso de micro-organismos tanto como indicadores da contaminação por poluentes quanto para a diminuição da contaminação, processo popularmente conhecido como biorremediação. Deste modo, o presente estudo teve como objetivos: 1) avaliar o efeito da presença de hidrocarbonetos na abundância de bactérias heterotróficas, cianobactérias e leveduras em sedimentos e águas estuarinas de duas regiões distintas, dos Estuários de Santos e do Rio Itanhaém, tanto no que diz respeito às características ambientais... / Coastal ecosystems have great socio-economic, political and cultural importance, as well as high productivity which support a wide range of economic activities and leisure. They have high landscape value thus attracting numerous people contributing to the development of coastal cities. Moreover, its high productivity supports biological communities and maintenance of many species living or using the coastal zone as a nursery for breeding, benefiting whole biodiversity. Being a region that suffers high anthropogenic pressure, the Coastal Zone is subject to numerous impacts caused by human activities such as port activities, industrial and oil exploration. These generate impacts on the environment by launching several pollutants, including hydrocarbons and metals that can have deleterious effects on local biota. The most affected marine environment is the sediment due to oil products that reach coastal waters have a higher density and end up being deposited in sediments. Nowadays there is great concern about the impacts generated by human activities on coastal ecosystems and many studies have been done in search of alternatives to evaluate and remedy such impacts. One alternative is the use of micro-organisms both as indicators of contamination by pollutants and for reduction of contamination, a process popularly known as bioremediation. Thus, this study aimed to evaluate the effect of the presence of hydrocarbons in the abundance of heterotrophic bacteria, cyanobacteria and yeast on sediment and estuarine waters of two distinct regions: The Estuaries of Santos and Itanhaém River are located in the metropolitan area of Santos, Sao Paulo State; and to isolate microorganisms with emphasis on yeasts, for further evaluation of its potential both as bioindicators of hydrocarbon contamination and bioremediation of estuarine sediments in order to contribute... (Complete abstract click electronic access below)

Um dos maiores problemas enfrentados pelas grandes cidades tem sido o gerenciamento de seus resíduos sólidos, principalmente no que tange seu descarte. Condições inadequadas de disposição desses resíduos causam inúmeros danos ao meio ambiente. Em cidades litorâneas é bastante comum a utilização dos manguezais como locais de disposição do lixo, resultando em sua degradação parcial ou mesmo total, levando muitas vezes ao desaparecimento desses ecossistemas. Durante mais de 50 anos a área de manguezal estudada neste trabalho serviu como local de descarte de resíduos provenientes das diversas atividades portuárias sendo utilizada como lixão e mesmo como aterro. Com o objetivo de estudar o comportamento geoquímico de íons de metais pesados chumbo, zinco, cobre e níquel foram analisados e estudados os atributos do solo/sedimento e as águas subterrâneas e superficiais do mar e do Rio Saboó, compartimentos próximos a área de estudos. Através de extrações parciais constatou-se que esses íons encontram-se acima dos valores de Referência de Qualidade da CETESB. O elevado teor de matéria orgânica, característico em área de manguezal, assim como a presença de minerais como illita, de elevado poder adsortivo, foram os principais responsáveis pela fixação iônica apesar das características texturais areno siltosa da área. A presença de íons de metais pesados nas águas subterrâneas e superficiais acima dos Padrões de Referência se deve ao contato do solo/sedimento com soluções com elevados valores de força iônica. Análises químicas do chorume, produto da percolação do antigo lixão, indicaram penas a presença de Pb em quantidades mais elevadas devido, principalmente, ao fenômeno de complexação com a matéria orgânica. / One of the biggest problems big cities are facing is how to manage its solid wastes, especially when we are talking about its disposal. Inadequate condition of its disposal causes many damages to environment. In coast cities are very common the use of mangroves as garbage disposal resulting in its partial or total degradation leading, many times, to ecosystems disappearances. For over 50 years the mangrove site studied in this project was the place of residual disposal from several harbor activities been used as landfill. With the aim to study the geochemistry behavior of ions of hevy metals, such as lead, zinc, copper and nickel, were analysed and studied the attributes of soil/sediment, groundwater and surface water from Saboó river, compartment close to the study field. Through partial extraction was proved that these ions were found above the values from Quality References of CETESB. High content of organic matter, characteristic in mangroves sites, just like the presence of minerals such as illite, which is very adsorptive, were the main responsible from ionic fixation despite the sandy-silty grains size characteristics of the area. The presence of ions in groundwater and superficial waters above the Reference Standarts is due to the contact of soil/sediment with solutions with high values of ionic force. Chemistry analysis of leachate, percolations product of the former landfill, indicated the presence only of Pb in high amount because of complexation phenomenon with the organic matter.

Os manguezais do Sistema Lagunar Cananéia-Iguape, no extremo sul do litoral do estado de São Paulo, possuem, em suas franjas mais externas, a presença da gramínea Spartina alterniflora, que exerce papel fundamental na fixação de sedimentos que poderão se tornar áreas de propagação do mangue. Pioneiras na região alagada do mangue, a Spartina segura e prepara o substrato para as plântulas de espécies de mangue se instaurarem. O mapeamento da Spartina alterniflora nas Ilhas de Cananéia e Comprida, onde estas ilhas margeiam o mesmo canal lagunar, possibilitou identificar as áreas propensas ao seu crescimento. Os pontos de baixa energia do fluxo de água do canal mostraram-se favoráveis ao surgimento de bancos de Spartina. A troca contínua de sedimentos e nutrientes existentes em um ambiente lagunar rico em manguezais, associada à grande capacidade de captação e fixação da Spartina, resultou em um estudo de conectividade entre duas ilhas. / The Cananéi-Iguape lagoon system, in the south shore of São Paulo state, has the presence of the cordgrass Spartina alterniflora on the outer side of the mangroves. The cordgrass has a fundamental role in the fixation of sediments which will be the mangrove\'s propagation areas. Pioneers in the mangrove wetlands, Spartina holds and prepare the substrate for the mangrove seedling establishment. Mapping the presence of Spartina alterniflora in the islands Ilha de Cananéia and Ilha Comprida, allowed to identify the prone areas for its growth. The points of low energy in the river were more favorable to create banks of Spartina. The continuous exchange of sediments and nutrients which exists in a mangrove lagoon system, associated with the great ability of Spartina to capture and establishment, resulted in a study of connectivity between two islands.

Coastal wetlands are globally important environments for biogeochemical cycling and are the object of intensive research related to the sequestration and exchange of carbon with oceans, continents, and the atmosphere. Wetland soil core records of organic carbon (OC) provide insights about future ecosystem responses to global change by identifying temporal variability in the context of environmental changes including sea level rise (SLR), anthropogenic reductions in freshwater flow, and landscape-scale disturbance events. My studies of Gulf of Mexico mangroves involved the use of radiometrically-dated soil cores to identify spatial and temporal accumulation trends of various constituents including organic and carbonate carbon, and macro-nutrients. My dissertation includes a literature review to assess the timescales of these processes and refine global perspectives on coastal wetland vulnerability. The contributions of organic and mineral matter to soil accretion (mm yr-1) was measured to (a) quantify how the supply of each may allow regional mangroves to keep pace with various SLR scenarios and, (b) assess wetland carbon sink capacity and stability in southwest Florida and the Yucatan Peninsula of Mexico. Mangroves in this region are largely devoid of terrigenous mineral sediments, and it has been hypothesized that storm surge-driven accretion of marine sediments could improve the capability of these locations to keep pace with SLR. Rates of accretion and organic matter accumulation were statistically similar across all four study regions, whereas mineral deposition rates ranged over two orders of magnitude. The volumetric contribution of mineral sediment to accretion is minimized by its high density. Organic matter, whose porous structures allow for highly variable densities, can contribute to a wide range of accretion rates and is a strong predictor of accretion. Future sustainability of these wetlands is more strongly dependent on the balance between soil organic matter production and preservation than the provision of storm-derived mineral sediments. To understand how OC sequestration will respond to SLR, the spatial and temporal variability of OC burial rates (g m-2 yr-1) were examined across ecosystem gradients in salinity, nutrient availability and mangrove productivity in the coastal Everglades. Results showed relatively little spatial variability and indicated that OC burial in the region is slow compared to rates in mangroves globally. However, significant regional differences in OC burial were observed in the context of primary productivity. Over a centennial timescale, mid-stream sites sequestered roughly 22% of annual net primary production and upstream sites preserved less than 10%. Least efficient sequestration occurs in the oligohaline ecotone, where increases in groundwater salinities and the potential for sulfate reduction have been recorded in the past decade. These findings indicate a significant slowdown in OC burial, and suggest that accelerating SLR will cause a substantial loss of historically sequestered carbon. The loss and potential out-welling of this carbon (including particulate and dissolved organic matter, dissolved CO2, and carbonate alkalinity) has important and complex implications for neighboring marine ecosystems including coral reefs and seagrass meadows. Several recent high-profile publications have used 5–15 years of soil accumulation rates to model wetland SLR-vulnerability outcomes over the next 50–100 years. To provide perspectives on these models, data that were generated from observations on multiple timescales (sub-annual to millennial) around the globe were used in a meta-analysis to determine the role of observational timescale on assessment outcomes. This analysis focused on rates of accretion and elevation change because of the wide availability of these data. Results demonstrate that rates of soil-body change exhibit a dependence on the length of time over which observations are made. Timescale hierarchies are driven by post-depositional diagenesis, ecosystem state changes, and regional effects primarily related to hydrology and sediment supply. Longer periods of observation utilizing multiple geochronological methods are needed to differentiate trend-changes from apparent changes that, in fact, may be due to regular periodicity. A conceptual model is presented that categorizes and explains timescale hierarchies in a soil’s geochemical history.

Orientador: Anete Pereira de Souza / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-27T05:05:38Z (GMT). No. of bitstreams: 1 Francisco_PatriciaMara_D.pdf: 7911618 bytes, checksum: f90010b3ff20ba6416b899bcfb99b443 (MD5) Previous issue date: 2015 / Resumo: Manguezais são ecossistemas com uma variedade incomum de animais e plantas adaptados às condições de alta salinidade, inundações frequentes e solo lodoso e anaeróbico. Ocorrem em locais onde há o encontro de águas de rios com a do mar. Diversos fatores bióticos e abióticos influenciam os padrões de diversidade de espécies de manguezais, como oceanografia, clima, topografia e condições do solo. A diversidade de plantas de mangue é muito reduzida, quando comparada com outros ecossistemas tropicais. O Brasil possui uma das maiores areas de manguezal do mundo e apresenta três gêneros de angiospermas de mangue. Um deles é Rhizophora, composto pelas espécies Rhizophora mangle, Rhizophora racemosa e, um possível híbrido, Rhizophora harrisonii. O objetivo da presente tese foi isolar e caracterizar locos microssatélites para essas espécies e estimar parâmetros populacionais como fluxo gênico, estruturação populacional, diversidade gênica e tamanho efetivo de população, além de estudar outros aspectos da biologia de Rhizophora, como uma possível zona de hibridação na região norte do país, taxa de cruzamento e o sistema reprodutivo. Com este propósito, foram coletados 318 indivíduos de R. mangle de 11 localidades ao longo da costa brasileira, e 33 indivíduos de R. racemosa e 37 indivíduos de R. harrisonii ambas coletadas de duas localidades no litoral brasileiro. Para identificar e caracterizar locos de microssatélites foram desenvolvidas bibliotecas enriquecidas em microssatélites para as três espécies. Utilizando os marcadores desenvolvidos na presente tese, bem como outros que já publicados, observou-se uma diferença significativa entre as populações no padrão de variação genética. A riqueza de alelos, heterozigosidades esperada e observada foram maiores na região norte. Os resultados sugerem que as espécies de Rhizophora não compõe apenas uma população panmítica ao longo do litoral brasileiro, devido à diferenciação existente entre as regiões norte e sul da costa. A análise do sistema reprodutivo de R. mangle de uma população do estado do Pará, encontramos valores que indicariam um sistema de reprodução misto. Em relação à hibridação contínua, não foram encontradas evidências de hibridação introgressiva entre as espécies de Rhizophora. Concluímos que com os resultados obtidos na presente tese foi possível contribuir para o maior conhecimento genético das espécies de Rhizophora spp. do litoral brasileiro / Abstract: Mangrove are ecosystems with an unusual variety of animals and plants adapted to conditions of high salinity and frequent floods and muddy anaerobic soil. Several abiotic factors influence the patterns of mangrove species diversity, such as oceanography, climate, topographic and soil conditions. The number of mangrove plant species is much reduced compared with other tropical ecosystems. Brazil has the second largest mangrove area in the world and has three genera of mangrove angiosperms. One genera is Rhizophora, composed of Rhizophora mangle, Rhizophora racemosa and a possible hybrid, Rhizophora harrisonii. The aim of this thesis was to isolate and characterize microsatellite loci for these species and estimate population parameters such as gene flow, population structure, genetic diversity and effective population size, and study other aspects of Rhizophora biology, as a possible hybrid zone in the north region of the Brazilian coast, crossing rate and the reproductive system. For this purpose, 318 individuals of R. mangle of 11 locations along the Brazilian coast, 33 individuals of R. racemosa and 37 individuals of R. harrisonii from two locations were collected. To identify and characterize the microsatellite loci, enriched microsatellite libraries for the three species were developed. Using the developed markers, and some others already published, we observed a significant difference between the populations in the pattern of genetic variation. Alleles richness, expected and observed heterozygosity were higher in the north. The results suggest that the species of R. mangle is not only composed of a single panmitic population due to differentiation found among the population from locales north and south of the Brazilian Coast. The reproductive system was evaluated studing a population of R. mangle from the state of Pará and we find values that would indicate a mixed mating system. Regarding the ongoing hybridization, we found no evidence of introgressive hybridization among the species leading to a hybrid species. We concluded that with this results it was possible to contribute to further genetic knowledge of Rhizophora spp. from the Brazilian coast / Doutorado / Genetica Vegetal e Melhoramento / Doutora em Genética e Biologia Molecular

The coastal ocean is a marginal region of the global ocean, but is home to metabolically intense ecosystems which increase the structural complexity of the benthos. These ecosystems have the ability to alter the carbon chemistry of surrounding waters through their metabolism, mainly through processes which directly release or consume carbon dioxide. In this way, coastal habitats can engineer their environment by acting as sources or sinks of carbon dioxide and altering their environmental chemistry from the regional norm. In most coastal water masses, it is difficult to resolve the ecosystem effect on coastal carbon biogeochemistry due to the mixing of multiple offshore end members, complex geography or the influence of variable freshwater inputs. The Red Sea provides a simple environment for the study of ecosystem processes at a coastal scale as it contains only one offshore end-member and negligible freshwater inputs due to the arid climate of adjacent land. This work explores the ability of three Red Sea benthic coastal habitats (coral reefs, seagrass meadows and mangrove forests) to create characteristic ecosystem end-members, which deviate from the biogeochemistry of offshore source waters. This is done by both calculating non-conservative deviations in carbonate stocks collected over each ecosystem, and by quantifying net carbonate fluxes (in seagrass meadows and mangrove forests only) using 24 hour incubations. Results illustrate that carbonate stocks over ecosystems conform to broad ecosystem trends, which are different to the offshore end-member, and are influenced by inherited properties from surrounding ecosystems. Carbonate fluxes also show ecosystem dependent trends and further illustrate the importance of sediment processes in influencing CaCO3 fluxes in blue carbon benthic habitats, which warrants further attention. These findings show the respective advantages of studying both carbonate stocks and fluxes of coastal benthic ecosystems in order to understand the spatial, temporal and net effects of their metabolism on the coastal ocean.

As ocean temperatures continue to rise, the effect of temperature on marine organisms becomes highly relevant. The Red Sea is the warmest sea and is rapidly warming with current surface temperatures (28 – 34 °C) already exceeding those of most tropical systems. This has major consequences for organisms that may already find themselves at their thermal limits. The aim of this project was to define the thermal limits and thresholds of certain Red Sea species. Firstly, to better understand the thermal regimes of the Red Sea, we looked at decadal trends in maximum sea surface temperature across the basin. Then, we tested the thermal capacities of Red Sea mangroves and zooplankton, two key ecological groups, by performing thermal stress experiments in the laboratory. We found that the Red Sea basin is warming faster than the global average (0.17 °C decade-1), the thermal limit of mangrove propagules is between 33 and 35 °C, and the limits among the most common zooplankton groups range from 30 to 36 °C. This project gives us a better understanding of how organisms respond to extreme temperatures and how they may be affected in a future, warmer, ocean.

Microorganisms are widespread in all ecosystems and play critical roles in nature. They are major players in global biogeochemical cycles that are fundamental in nutrient cycling. Molecular ecology surveys that investigate the microbial diversity of many different environments have revealed an impressive diversity of microbes in nature and have highlighted our inability to cultivate the vast majority of them in the laboratory. The improvement of our ability to grow uncultivable microbes in laboratory conditions will help us in this challenging task. Standard cultivation methods that have helped to bring to culture many relevant microorganisms in the past century are, however, characterized by limitations which hamper the isolation of novel microbes. For this reason, alternative cultivation strategies have been developed in recent decades which have allowed to expand the collection of environmentally relevant but poorly represented microbial strains. The use of such novel approaches for investigating the microbial diversity of underexplored natural ecosystems, such as sub-tropical mangrove forests, can result in the isolation, in laboratory conditions, of bacterial strains belonging to previously undescribed taxa. Mangroves are unique environments exposed to strong selection forces with respect to other marine environments, including high temperatures, salinity and oligotrophy. I hypothesize that these unique combinations of environmental features have selected microbiomes with unique characteristics. The aim of this PhD research is to explore the bacterial diversity of the Red Sea mangrove ecosystem, by applying an alternative cultivation strategy that uses oligotrophic conditions and long incubation time. I also exploited the diffusion chamber to cultivate bacterial taxa belonging to rarely isolated or even novel genera. This approach allowed me to isolate four novel bacterial taxa. Using 16S rRNA gene sequencing, the isolated bacteria were identified as one novel species and three novel genera belonging to Alpha-proteobacteria, Bacteroidetes, and Firmicutes, respectively. These isolates were further characterized and described through genomic, phylogenetic, chemotaxonomic, and phenotypic analysis to describe their ecological significance in the ecosystem of origin (i.e., mangrove sediments). This study reveals that the extreme conditions of the Red Sea mangroves have selected a unique and yet mostly untapped culturable microbiome with great potential for environmental applications.