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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Raising Islands

Knight, Christopher James Snazel 11 May 2012 (has links)
In an era of dawning anthropogenic climate change, people of atoll nations face grievous threats to their future. Rising sea levels, warming oceans, and changing weather patterns conspire with economic isolation, rapidly growing populations, and the loss of traditional livelihoods to perpetuate conditions of dependence and wardship which threaten the very existence of their island homes. This project examines an atoll nation of the equatorial Pacific, the Republic of the Marshall Islands, where the outward appearance of pristine tropical paradise belies a tragic history of nuclear weapons and ballistic missile testing at the hands of the US military. While the islands have been consistently framed in rhetoric which stresses vulnerability, smallness and unsustainability, this project contests the limited scope of the regimes of power in Oceania by considering how the independent, grassroots actions of local groups of islanders have achieved surprising and dramatic results in defiance of the policies and planners at the top. In developing a design proposal for the contemporary condition, this thesis examines the persistent ways in which the islands and people are framed by outsiders. This project engages with the social, political and natural history of the atolls: common tropes are challenged by the actions and agency of a people who have dealt with imperialist outsiders in sophisticated and conscious ways. It explores the traditional cultural practices which enabled the ancestors of the Marshallese people to flourish, and suggests that it is at the level of actions by ordinary people that the most fertile potentials lie, and are in fact already being played out. What forms of urbanism might be appropriate in this environment? How can islanders effectively manage their landscape and engage with the natural processes - as their ancestors once did to a remarkable degree? By pairing traditional techniques with modern technologies, a proposal is synthesized which could empower the contemporary Marshallese to transform their landscape and develop sustainable livelihoods in this extreme and dynamic environmental condition: to build a future which offers the best aspects of both traditional and contemporary ways of life.
22

Geobiologia do Atol das Rocas, Atlântico Sul Equatorial

Soares, Marcelo de Oliveira January 2009 (has links)
Esta tese aborda a geobiologia do único Atol do Oceano Atlântico Sul. Diferentes classificações foram realizadas para o complexo recifal de Rocas ao longo dos séculos XIX e XX, as quais são avaliadas historicamente. Análises biogeomorfológicas e de mapeamento das unidades recifais foram realizadas no Atol das Rocas para a compreensão da dinâmica sedimentar e do relevo deste recife oceânico. Os diferentes compartimentos recifais são afetados por processos biogeomorfológicos como controle de processos erosivos, bioproteção, bioerosão recifal, bioturbação, cimentação de areia carbonática biogênica, produção de sedimentos biodetríticos e bioconstrução (principalmente de algas calcáreas, corais, vermetídeos e foraminíferos). Organismos diversos incluindo aves, peixes, tartarugas, corais, zoantídeos, algas, moluscos, poliquetas, sipunculídeos, foraminíferos e microorganismos agem nos diferentes grupos de processos biogeomorfológicos gerando as características únicas do Atol. O recife oceânico se desenvolveu provavelmente nos últimos 7000 anos do Período Neógeno. A paleohidrodinâmica da corrente oceânica, variações no gradiente de energia no lado a barlavento e sotavento e, sobretudo, as oscilações eustáticas holocênicas foram preponderantes na evolução recifal. Em níveis de mar alto uma grande laguna composta por comunidades bentônicas se formou com grande diversidade biológica. Eventos regressivos e de erosão por ação de ondas e correntes levou as feições observadas atualmente, tais como o ambiente lagunar raso (<6m profundidade), de um amplo depósito arenoso e das ilhas à sotavento. A dinâmica temporal e espacial de sete comunidades principais de ambientes submersos, intertidais e emersos é demonstrada pela primeira vez. / This thesis approaches the geobiology of the only Atoll in the South Atlantic Ocean. Different classifications were made for Rocas Reef Complex along the nineteenth and twentieth century, which are evaluated historically. Biogeomorphological analysis and mapping of the reef units were done on the Rocas Atoll for the comprehension of the sedimentary dynamic and of the relief of this oceanic reef. The different reef compartments are affected by biogeomorphological processes such as erosive process control, bioprotection, bioerosion, bioturbation, cementing of the biogenic carbonate sand, production of biodetritic sediments and bioconstruction (especially of calcareous algae, vermetids, corals and foraminifers). Different organisms including birds, fishes, turtles, corals, zoanthids, algae, mollusks, polychaets, sipunculids, foraminifers and microorganisms act in the different groups of biogeomorphological processes generating the unique characteristics of the Atoll. The oceanic reef developed over the past 7000 years in the Neogene Period. The paleohydrodynamic of the oceanic current, variations of the gradient of energy on the leeward/windward side and, above all, the eustatic holocenic oscillations were predominant in the reef evolution. In high sea levels a lagoon composed by bentonic communities formed with great biological diversity. The regression and erosion by waves and currents led to the formation of shallow lagoon environment, extensive sandy deposit and the Islands in leeward side. The temporal and spatial dynamic of seven main communities of underwater, intertidal and emerged environments is shown for the first time.
23

Geobiologia do Atol das Rocas, Atlântico Sul Equatorial

Soares, Marcelo de Oliveira January 2009 (has links)
Esta tese aborda a geobiologia do único Atol do Oceano Atlântico Sul. Diferentes classificações foram realizadas para o complexo recifal de Rocas ao longo dos séculos XIX e XX, as quais são avaliadas historicamente. Análises biogeomorfológicas e de mapeamento das unidades recifais foram realizadas no Atol das Rocas para a compreensão da dinâmica sedimentar e do relevo deste recife oceânico. Os diferentes compartimentos recifais são afetados por processos biogeomorfológicos como controle de processos erosivos, bioproteção, bioerosão recifal, bioturbação, cimentação de areia carbonática biogênica, produção de sedimentos biodetríticos e bioconstrução (principalmente de algas calcáreas, corais, vermetídeos e foraminíferos). Organismos diversos incluindo aves, peixes, tartarugas, corais, zoantídeos, algas, moluscos, poliquetas, sipunculídeos, foraminíferos e microorganismos agem nos diferentes grupos de processos biogeomorfológicos gerando as características únicas do Atol. O recife oceânico se desenvolveu provavelmente nos últimos 7000 anos do Período Neógeno. A paleohidrodinâmica da corrente oceânica, variações no gradiente de energia no lado a barlavento e sotavento e, sobretudo, as oscilações eustáticas holocênicas foram preponderantes na evolução recifal. Em níveis de mar alto uma grande laguna composta por comunidades bentônicas se formou com grande diversidade biológica. Eventos regressivos e de erosão por ação de ondas e correntes levou as feições observadas atualmente, tais como o ambiente lagunar raso (<6m profundidade), de um amplo depósito arenoso e das ilhas à sotavento. A dinâmica temporal e espacial de sete comunidades principais de ambientes submersos, intertidais e emersos é demonstrada pela primeira vez. / This thesis approaches the geobiology of the only Atoll in the South Atlantic Ocean. Different classifications were made for Rocas Reef Complex along the nineteenth and twentieth century, which are evaluated historically. Biogeomorphological analysis and mapping of the reef units were done on the Rocas Atoll for the comprehension of the sedimentary dynamic and of the relief of this oceanic reef. The different reef compartments are affected by biogeomorphological processes such as erosive process control, bioprotection, bioerosion, bioturbation, cementing of the biogenic carbonate sand, production of biodetritic sediments and bioconstruction (especially of calcareous algae, vermetids, corals and foraminifers). Different organisms including birds, fishes, turtles, corals, zoanthids, algae, mollusks, polychaets, sipunculids, foraminifers and microorganisms act in the different groups of biogeomorphological processes generating the unique characteristics of the Atoll. The oceanic reef developed over the past 7000 years in the Neogene Period. The paleohydrodynamic of the oceanic current, variations of the gradient of energy on the leeward/windward side and, above all, the eustatic holocenic oscillations were predominant in the reef evolution. In high sea levels a lagoon composed by bentonic communities formed with great biological diversity. The regression and erosion by waves and currents led to the formation of shallow lagoon environment, extensive sandy deposit and the Islands in leeward side. The temporal and spatial dynamic of seven main communities of underwater, intertidal and emerged environments is shown for the first time.
24

Geobiologia do Atol das Rocas, Atlântico Sul Equatorial

Soares, Marcelo de Oliveira January 2009 (has links)
Esta tese aborda a geobiologia do único Atol do Oceano Atlântico Sul. Diferentes classificações foram realizadas para o complexo recifal de Rocas ao longo dos séculos XIX e XX, as quais são avaliadas historicamente. Análises biogeomorfológicas e de mapeamento das unidades recifais foram realizadas no Atol das Rocas para a compreensão da dinâmica sedimentar e do relevo deste recife oceânico. Os diferentes compartimentos recifais são afetados por processos biogeomorfológicos como controle de processos erosivos, bioproteção, bioerosão recifal, bioturbação, cimentação de areia carbonática biogênica, produção de sedimentos biodetríticos e bioconstrução (principalmente de algas calcáreas, corais, vermetídeos e foraminíferos). Organismos diversos incluindo aves, peixes, tartarugas, corais, zoantídeos, algas, moluscos, poliquetas, sipunculídeos, foraminíferos e microorganismos agem nos diferentes grupos de processos biogeomorfológicos gerando as características únicas do Atol. O recife oceânico se desenvolveu provavelmente nos últimos 7000 anos do Período Neógeno. A paleohidrodinâmica da corrente oceânica, variações no gradiente de energia no lado a barlavento e sotavento e, sobretudo, as oscilações eustáticas holocênicas foram preponderantes na evolução recifal. Em níveis de mar alto uma grande laguna composta por comunidades bentônicas se formou com grande diversidade biológica. Eventos regressivos e de erosão por ação de ondas e correntes levou as feições observadas atualmente, tais como o ambiente lagunar raso (<6m profundidade), de um amplo depósito arenoso e das ilhas à sotavento. A dinâmica temporal e espacial de sete comunidades principais de ambientes submersos, intertidais e emersos é demonstrada pela primeira vez. / This thesis approaches the geobiology of the only Atoll in the South Atlantic Ocean. Different classifications were made for Rocas Reef Complex along the nineteenth and twentieth century, which are evaluated historically. Biogeomorphological analysis and mapping of the reef units were done on the Rocas Atoll for the comprehension of the sedimentary dynamic and of the relief of this oceanic reef. The different reef compartments are affected by biogeomorphological processes such as erosive process control, bioprotection, bioerosion, bioturbation, cementing of the biogenic carbonate sand, production of biodetritic sediments and bioconstruction (especially of calcareous algae, vermetids, corals and foraminifers). Different organisms including birds, fishes, turtles, corals, zoanthids, algae, mollusks, polychaets, sipunculids, foraminifers and microorganisms act in the different groups of biogeomorphological processes generating the unique characteristics of the Atoll. The oceanic reef developed over the past 7000 years in the Neogene Period. The paleohydrodynamic of the oceanic current, variations of the gradient of energy on the leeward/windward side and, above all, the eustatic holocenic oscillations were predominant in the reef evolution. In high sea levels a lagoon composed by bentonic communities formed with great biological diversity. The regression and erosion by waves and currents led to the formation of shallow lagoon environment, extensive sandy deposit and the Islands in leeward side. The temporal and spatial dynamic of seven main communities of underwater, intertidal and emerged environments is shown for the first time.
25

Comunidade de peixes nas piscinas de maré do Atol das Rocas, Brasil : a influência da conexão com o mar

CARNEIRO, Isis Santos Cabral 22 February 2016 (has links)
Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-08-09T11:59:41Z No. of bitstreams: 1 Isis Santos Cabral Carneiro.pdf: 1623059 bytes, checksum: c3b08c3aad9561bb6e52b0ccf1e4e5d0 (MD5) / Made available in DSpace on 2016-08-09T11:59:41Z (GMT). No. of bitstreams: 1 Isis Santos Cabral Carneiro.pdf: 1623059 bytes, checksum: c3b08c3aad9561bb6e52b0ccf1e4e5d0 (MD5) Previous issue date: 2016-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The reef environments have the highest species diversity among marine ecosystems. The reef fish communities are characterized by their high diversity, both in terms of numbers of species as in morphology and are important components of the biota of these environments, working in the structuring of communities through predation and competition processes. The structure of fish populations respond to various environmental factors (rainfall regime, environmental geomorphology, tidal dynamics, water transparency, quality and type of organic matter, current velocity and availability of food resources), these factors influence the spatial distribution and temporal species. Thus, this aimed to understand the timeline distribution of fish populations between the pools with or without connection to the open sea in Rocas Atoll, identifying the environmental characteristics with the greatest influence on the structure of fish populations. This is the only atoll in the South Atlantic Ocean and is located 266 km off the Brazilian coast, differs from other atolls because it is composed exclusively of algae encrusting coralline. In its plateau occur tidal pools, canals and sandy islands. 90 hours of diving were held in two pools with connection to the open sea and two disjoint through five linearly arranged transects the edge to the center of the pool, including the dry and rainy seasons. The temperature data were recorded, salinity, pH and dissolved oxygen from each pool much water in the dry season and the rainy. It was identified to the substrate composition of the pools through the photos using the methodology Coral Point Count with Excel Extensions program. 12,065 individuals, distributed in 20 families and 33 species were observed. The pools with connection with the sea showed the highest values of diversity and abundance and presented as the most abundant species Thalassoma noronhanum, Acanthurus chirurgus, Abudefduf saxatilis and Stegastes rocacensis, these species are equivalent to 87.3% of relative abundance these pools. The pools without connection with the sea showed a difference in the fish community in comparison to the pools with connection, being the most abundant species the A.saxatilis, A. chirurgus, T. noronhanum and Haemulon chrysargyreum. The richness, diversity and equitability varied between climatic periods and connection type. A significant correlation between the diversity and depth (RS 0,322e = p <0.05) was observed. They were observed seven types of substrate: coral, zoanthid, turf algae, seaweed, corallinae algae, gravel and sand. The substrate showed a correlation between the two pools open with rS = 0.857, p <0.05 where both presented seaweed as most of the substrate. In Rocas Atoll the connection type and depth of the pool, time of year and the type of substrate influence the composition and distribution of fish populations between the pools. / Os ambientes recifais apresentam a maior diversidade de espécies dentre os ecossistemas marinhos. As comunidades de peixes recifais são caracterizadas pela sua elevada diversidade, tanto em termos de números de espécies como em morfologia, sendo componentes importantes da biota destes ambientes, atuando na estruturação das comunidades através de processos de predação e competição. A estrutura da ictiofauna responde a diversos fatores ambientais (regime de pluviosidade, geomorfologia do ambiente, dinâmica da maré, transparência da água, qualidade e tipo de matéria orgânica, velocidade das correntes e disponibilidade dos recursos alimentares), esses fatores influenciam na distribuição espacial e temporal das espécies. Desta forma, o presente objetivou compreender a distribuição espaço temporal da ictiofauna entre as piscinas com ou sem conexão com o mar aberto no Atol das Rocas, identificando as características ambientais com maior influência na estruturação da ictiofauna. Este é o único atol do Oceano Atlântico Sul e está localizado a 266 km da costa brasileira, difere dos outros atóis porque é composto exclusivamente por algas coralíneas incrustantes. Em seu platô ocorrem piscinas de maré, canais e ilhas arenosas. Foram realizadas 90 horas de mergulho, em duas piscinas com conexão com o mar aberto e duas sem conexão, por meio de cinco transectos dispostos linearmente da borda para o centro da piscina, abrangendo os períodos seco e chuvoso. Foram registrados os dados de temperatura, salinidade, pH e oxigênio dissolvido da água de cada piscina tanto no período seco como no chuvoso. Foi identificada a composicão do substrato das piscinas através da metodologia de fotografias utilizando o programa Coral Point Count with Excel Extensions. Foram observados 12.065 indivíduos, distribuídos em 20 famílias e 33 espécies. As piscinas com conexão com o mar apresentaram os maiores valores de diversidade e abundância e apresentaram como espécie mais abundantes Thalassoma noronhanum, Acanthurus chirurgus, Abudefduf saxatilise, Stegastes rocacensis, essas espécies equivalem a 87,3% da abundância relativa dessas piscinas. As piscinas sem conexão com o mar apresentaram uma diferença na composição ictiofaunística em comparação com as piscinas fechadas, sendo as espécies mais abundantes o Abudefuf saxatilis, A. chirurgus, T. noronhanum e Haemulonchrysargyreum. Os valores de riqueza, diversidade e equitabilidade variaram entre períodos climáticos e tipo de conexão. Foi observada uma correlação entre a diversidade e profundidade (rS=0,322e p<0,05).Foram observados sete tipos de substrato: coral, zoantídeo, alga turf, macroalga, alga coralínea, cascalho e areia. O substrato apresentou correlação entre as duas piscinas abertas com rS =0,857 e p<0,05 onde ambas apresentaram macroalgas como maior parte do substrato. No Atol das Rocas o tipo de conexão e profundidade da piscina, período do ano e o tipo de substrato influenciam na composição e distribuição da ictiofauna entre as piscinas.
26

Látková bilance a zonální stavba hlavních a stopových prvků v atolovém granátu z metabazitu eklogitové facie. / Mass balance and major and trace element zoning in atoll garnet from eclogite facies metamorphism.

Kulhánek, Jan January 2018 (has links)
English abstract This work focuses on high pressure atoll garnet-bearing metabasites from the central part of Krušné hory Mts. in Saxothuringian zone of Bohemian Massif. Eclogite bodies are interpreted as a part of alochtonnous units, which were dragged into the high pressure conditions of subduction zone during a subduction of Saxothuringian oceanic crust under the Teplá-Barrandien Unit and subsequently they were exhumed into upper parts of subduction- collisional system. Main mineral assemblage of eclogites consists of omphacite, garnet, quartz and amphibole which replaces grains of omphacite. Minor minerals present are rutile, ilmenite, talc a chlorite. Zircon, apatite, paragonite, pyrite, plagioclase, albite and monazite are enclosed in porphyroblasts of garnets. Grains of garnet frequently form the atoll structures, where its central part of a grain is replaced by new minerals of matrix and rim part stays preserved. Based on compositional profiles and mapping of major and trace elements, two evolution phases of garnet were distinguished. Older garnet (I) forms mainly preserved cores of garnet and on the contrary younger garnet (II) is present on rims or also replaces garnet I in the core part of a grain. Garnet I has higher amounts of Ca and Mn but lower Mg and Fe than garnet II. Preserved grains of...
27

Etude des transferts d'eau et de nitrate dans les sols ferrallitiques de Maré (Nouvelle-Calédonie) : risques de pollution des lentilles d'eau douce

Duwig, Céline 08 September 1998 (has links) (PDF)
Le but principal de cette thèse est la détermination des risques de pollution de l'eau souterraine dus à des pratiques agricoles intensives sur l'île de Maré (Nouvelle-Calédonie). Maré est un atoll corallien surélevé où la principale ressource en eau douce provient de lentilles situées à l'intérieur du soubassement corallien. Le sol est un sol ferrallitique allitique très pérméable, et possédant une capacité importante d'échange anionique. Le climat est caractérisé par une saison humide, où des événements pluvieux de fortes intensités peuvent survenir. Pour calculer le drainage et la lixiviation du nitrate en-dessous de la zone racinaire, une métrologie non destructive a été mise en oeuvre sur plusieurs parcelles soumises à différentes pratiques culturales. Les caractéristiques hydrauliques du sol ont été obtenues par infiltrométrie et les paramètres de transfert de solutés grâce à des expériences réalisées au laboratoire, sur colonnes de sol. Environ 100 kg N ha-1 ont été apportés sur une parcelle sol nu, de maïs et de graminées. Bien que la saison 1996 fut plus humide qu'en 1995, la quantité de nitrate livixié sous maïs a diminué de 130 % (1995) à 48 % (1996) du nitrate apporté. En 1996, l'engrais a été apporté en deux fois alors qu'en 1995, il a été apporté en totalité le jour du semis. Malgré sa capacité d'échange anionique, la perméabilité du sol ainsi que les fortes intensités de pluie concourent à rendre le nitrate facilement lixiviable. Cependant, le risque de pollution peut être fortement réduit avec des applications fractionnées d'engrais de manière à ce que la consommation du nitrate par les plantes soit améliorée. Les paramètres du sol déterminés sur le terrain et au laboratoire nous ont permis d'utiliser le modèle mécaniste WAVE et d'évaluer sa capacité de reproduction et de prédiction des données. Les mesures lors des trois saisons aux conditions climatiques différentes ont été reproduites avec satisfaction.
28

Land and lineage : the articulation of social and physical space in an atoll village : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Sociology at Massey University

King, Peter Stanton January 1996 (has links)
This thesis examines relationships between the social and physical environments of a village on Butaritari atoll in Kiribati. The system of ambilineal descent and land inheritance obtaining there results in complex networks of genealogical relationships which affect most aspects of social life, including land rights. While previous studies conducted in Kiribati have recognised the intimate connection between genealogy and land rights, none has investigated its ramifications for the distribution of land rights within a community. In contrast, this study engages that question as a central concern using a framework which integrates Bourdieu's concepts of social space, field and habitus with post-neo-Darwinian ideas about the relationship between organism and environment. The social space was found to be primarily structured by relationships based upon genealogy and secondarily by age and gender, each of which constituted a field within the wider social space. The genealogical field was defined by a network of positions, each representing a particular descent group. In accordance with the prevailing system of ambilineal descent, residents could belong to more than one descent group and it was upon the resulting networks of relationships between descent groups that the disposition of those groups within the genealogical field was defined. Because land-use rights were associated with genealogical connections the reconstruction of the genealogical field encompassing all of the village residents was a necessary precursor to discovering the distribution of those rights and the genealogical field was a central point of articulation between the social and physical spaces. The fields of age and gender relations provided further points of articulation between the social and physical spaces, the natures of which are examined through discussion of the material culture of the village and village and island politics. Despite a contemporary ideology of egalitarianism there were vestiges of a former hierarchy of social status groups. While the inter-group obligations, rights and responsibilities associated with this hierarchy were no longer practised, the association of contemporary residents with those social status groups bore a relationship to their position within the genealogical field and the amounts of land to which they shared rights.
29

Perspectivas dos efeitos do aumento do CO2 atmosférico sobre os organismos construtores do Atol das Rocas- RN

PINHEIRO, Barbara Ramos 30 August 2016 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-04-26T16:06:29Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese_Pinheiro_BR_2016_PPGO_UFPE.pdf: 4797187 bytes, checksum: 23d620ab5ad4e454bcb109d992f47da5 (MD5) / Made available in DSpace on 2017-04-26T16:06:29Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese_Pinheiro_BR_2016_PPGO_UFPE.pdf: 4797187 bytes, checksum: 23d620ab5ad4e454bcb109d992f47da5 (MD5) Previous issue date: 2016-08-30 / O aumento da pressão parcial de dióxido de carbono (pCO2) na atmosfera, que passou de uma média de 280ppm antes da revolução industrial para acima de 400ppm nos dias atuais, é um dos principais responsáveis por uma série de mudanças globais. Entre elas, a elevação da temperatura superficial da água do mar (TSM), a elevação do nível do mar, e a acidificação oceânica (AO). Os ambientes recifais têm sido apontados como os mais vulneráveis a estas mudanças. Efeitos da elevação da pCO2 sob ambientes recifais no Atlântico Sul, são escassos e na sua maioria reportam apenas efeitos da elevação da TSM e eventos de branqueamento. O Atol das Rocas é a primeira Reserva Biológica marinha do Brasil e foi escolhido neste estudo por ser um exemplo de recife biogênico, oceânico e praticamente livre de impactos como sobrepesca, poluição, e turismo desordenado. Desta forma, o objetivo do presente estudo foi avaliar os efeitos da elevação da pCO2 atmosférica sob os organismos construtores do atol para estabelecer um ponto de referência para futuras comparações, devido a sua vulnerabilidade a estes processos. A pesquisa foi dividida em três etapas, sendo essas a caracterização, a avaliação do estado e a experimentação dos prováveis efeitos da acidificação nos organismos calcários. Inicialmente são apresentados dados sobre a cobertura bentônica e a sua interação com os parâmetros abióticos (temperatura, salinidade, disponibilidade de nutrientes dissolvidos, pH e alcalinidade total). Foi observada dominância de macro e tufos de algas em locais com maior disponibilidade de nutrientes dissolvidos, indicando que maiores concentrações de nutrientes inorgânicos na água do mar contribuem para a distribuição dos organismos no atol. E, além disso, ambientes com alta frequência de organismos carbonáticos foram associados com uma diminuição da concentração de alcalinidade. Em seguida, dados foram obtidos sobre reprodução, crescimento e distribuição de frequência da população da espécie de coral dominante nas piscinas do atol (Siderastrea stellata). Foi observado um evento de planulação e o crescimento inicial dos pólipos primários, os quais, após 3 meses mostraram uma média de diâmetro de 1,49±0,45 mm, variando entre 0,9 e 2,28 mm e 14,70% de taxa de mortalidade. A média da taxa de extensão anual das colônias adultas foi de 6,8 ± 0,7 mm. ano-1. Colônias com 4,1 a 10 cm de diâmetro também foram frequentes no atol (48,1±14,5%). A população de S. stellata no atol mostra-se com um alto potencial de manutenção e recuperação, embora tenha sido observado uma baixa taxa de recrutamento. Na outra etapa do estudo se fez uma caracterização do sistema carbonato no atol, avaliando a influência do metabolismo dos organismos sob as variações espaço-temporais observadas. Os resultados indicaram uma grande disponibilidade de carbonato dissolvido nas piscinas do atol. Os índices de saturação de aragonita não só suprem as necessidades metabólicas dos organismos, como estão acima dos observados para outros ambientes recifais. Desta forma, é possível que a intensa atividade biológica no atol das rocas possa servir como um tampão adicional para o equilíbrio do pH e mitigar alguns dos efeitos da acidificação oceânica localmente. Por fim, foi realizado um experimento com espécies que ocorrem no atol, o coral scleractíneo Porites astreoides e o zoantídeo Palythoa caribaeorum. Foram avaliadas as respostas fisiológicas (crescimento, respiração, fotossíntese, lipídios totais e clorofila a) desses organismos mediante condições de estresse térmico e acidificação. P. astreoides sofreu influência do aquecimento e da acidificação em todas as taxas metabólicas avaliadas, enquanto o P. caribaeorum teve um menor, ou nenhum impacto no seu metabolismo. / The increase in carbon dioxide partial pressure (pCO2) in the atmosphere, which rose from an average of 280 ppm before pre-industrial times to over 400 ppm today, it is one of the main responsible for a series of global changes. Among them, increasing sea surface temperature (SST), sea level rise and ocean acidification (OA). Coral reefs have been identified as the most vulnerable ecosystem to these changes. Investigations about the effects of elevated anthropogenic pCO2 on coral reef environments in the South Atlantic are scarce and mostly only effects of the increase of SST and bleaching events were reported. Rocas Atoll is the first Marine Biological Reserve in Brazil and was chosen in this study because it is an example of a oceanic biogenic reef, and virtually free from impacts such as overfishing, pollution, and unregulated tourism. Thus, the aim of this study was to evaluate the effects of increased atmospheric pCO2 on the atoll building organisms to establish a benchmark for future comparisons, because of their vulnerability to these processes. Initially are presented data on the benthic cover and its interaction with the abiotic parameters (temperature, salinity, availability of dissolved nutrients, pH and total alkalinity). It was observed a dominance of macro and tuff algae in places with higher availability of dissolved nutrients, indicating that higher concentrations of inorganic nutrients in seawater contribute to the spatial distribution of organisms on the atoll. And besides, environments with high frequency of carbonate organisms were associated with a decrease of alkalinity. Then, data were obtained on reproduction, growth and frequency distribution of the population of the dominant coral species in the atoll pools (Siderastrea stellata). A planulation event was observed and initial growth of primary polyps which, after 3 months showed 1.49 ± 0.45 mm average diameter ranging between 0.9 and 2.28 mm and 14.70% mortality rate. The average annual extension rate of adult colonies was 6.8 ± 0.7 mm. year-1. Colonies with 4.1 to 10 cm diameter were also common in the atoll (48.1 ± 14.5%). The population of S. stellata in the atoll shows a high potential for maintenance and recovery, although it was observed a low recruitment rate. In another stage of the study, a characterization of the carbonate system of the atoll was made, in order to assess the influence of the metabolism of organisms under spatio-temporal variations. The results indicated a large availability of dissolved carbonate in the atoll pools. The aragonite saturation rates not only supply the metabolic demands of the corals, but are above those observed for other coral reef environments. Thus, it is possible that the intense biological activity of the Rocas Atoll can serve as an additional buffer for the pH equilibrium and locally mitigate some of the effects of ocean acidification. Finally, an experiment was conducted with species that occur in the atoll, the scleractinian coral Porites astreoides and the zoanthid Palythoa caribaeorum. The physiological responses of these organisms were evaluated (growth, respiration, photosynthesis, total lipids and chlorophyll a) under conditions of heat stress and acidification. P. astreoides was influenced by warmer temperatures and acidification in all measured metabolic rates while P. caribaeorum showed a minor or no impact on your metabolism.
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Contaminated and Scarred: An Exploration in the Landscapes and Narratives of the Anthropocene / Förorenat och ärrat: En utforskning av de antropoceniska landskapen och narrativen

Pietilä, Laura January 2020 (has links)
In this thesis, I explore and analyse narratives around toxic and scarred landscapes. The aim of the thesis is to understand human views and experiences of anthropogenic environments through narratives of contamination and toxicity. Some concepts used throughout the thesis are landscape, heritage, ghost, and trauma. The research is situated in the transdisciplinary field of environmental history and utilises multidisciplinary academic research, art works, and several different media outlets as sources of data. Many brief examples of toxic sites are given along the way to demonstrate discussed themes in practice, but two specific landscapes are explored in detail. These are Bikini Atoll in Marshall Islands, an island remaining radioactive to date due to Cold War era weapon testing, and the town of Teckomatorp in Sweden, a remediated site of a chemical industry scandal. Furthermore, an academic environmental justice project Toxic Bios (KTH, Stockholm) is analysed as a medium of narrative creation and several visual artists’ works are brought up alongside news articles and cinematography. This thesis is an exploratory journey and it aspires to contribute to bridging academic disciplines as well as encouraging expression of individual stories and subjective viewpoints in narrations of scarred landscapes. Findings of the thesis link to previous research on landscapes as experienced and temporal – toxic landscapes are narrated constantly through many perceptions, storylines, and branches of research. Some reoccurring themes are sickness, environmental justice, tensions between local and global levels of narration, fascinating but controversial depictions of toxicity’s aesthetics and individual experiences of dramatic pasts in non-dramatic present. Individual stories, counter-hegemonic narratives, and transdisciplinary practices are needed in order to create deeper understanding of living in the Anthropocene.

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