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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.
71

Changes in the Great Barrier Reef since European settlement : implications for contemporary management /

Daley, Benjamin. January 2005 (has links)
Thesis (Ph.D.) - James Cook University, 2005. / Typescript (photocopy) Bibliography: p. 511-553.
72

Predator-prey interactions in coral reef fish : the implications of predation risk on the behavior and growth of prey /

Abdulla, Ameer. January 2004 (has links)
Thesis (Ph.D.) - James Cook University, 2004. / Typescript (photocopy) Bibliography: leaves 127-154.
73

An evaluation of prior residency and habitat effects on the persistence of settling reef fishes : a thesis submitted to the Victoria University of Wellington in fulfilment of the requirements for the degree of Doctor of Philosophy in Marine Biology /

Geange, Shane Wallace. January 2010 (has links)
Thesis (Ph.D.)--Victoria University of Wellington, 2010. / Includes bibliographical references.
74

The effects of ocean acidification on zooplankton : using natural CO2 seeps as windows into the future

Smith, Joy January 2016 (has links)
Since the beginning of the Industrial Revolution, carbon dioxide (CO2) has been emitted into the atmosphere at rates unprecedented to Earth’s history. Nearly 30% of the anthropogenic CO2 in the atmosphere has been absorbed in surface waters of the ocean, pushing carbonate chemistry towards increased bicarbonate ions and hydrogen protons and decreased carbonate ions. Consequently, seawater pH has decreased from pre-Industrial Revolution levels of 8.2 to current levels of 8.1, and it is expected to continue to drop to 7.8 by the year 2100 if carbon emissions continue as predicted. The combination of these effects is referred to as ocean acidification. It is at the forefront of marine research as it poses a serious threat to several marine organisms and ecosystems. Ocean acidification has the most notable direct effect on calcifying organisms with calcium carbonate skeletons and shells, because fewer carbonate ions in the water column result in reduced calcification. Coral reefs are especially vulnerable to ocean acidification since reefs are composed of complex carbonate structures. Coral reefs have a high biodiversity; thus, not only will the corals themselves be affected by ocean acidification, but so will many of the animals that dwell in them. The primary objective of this thesis was to examine the effects of ocean acidification on demersal zooplankton that reside in coral reefs. Ocean acidification research on zooplankton has primarily been single- species experiments on calcifying species or generalist copepod species. Scaling-up to experiments examining ocean acidification effects on entire zooplankton communities is logistically difficult, thus the ability to predict community changes in zooplankton due to ocean acidification has been rather limited. However, a few locations around the world have submarine volcanic CO2 seeps that can be used as natural laboratories to study ecosystem effects of ocean acidification. Two CO2 seeps located in coral reefs in Papua New Guinea were used as windows into the future to examine the effects of ocean acidification on entire zooplankton communities while they live naturally in their environment. Over three expeditions to two CO2 seeps, nocturnal plankton were sampled with horizontal net tows and emergence traps. Additional experiments were also conducted, and collectively this work is summarized in chapters 2-5 as outlined below. Chapter 2 reports on the observed changes in zooplankton abundance and community composition between control and high-CO2 sites. Consistent results between seep sites and expeditions showed that zooplankton abundances were reduced three-fold under high-CO2 conditions. The abundance loss was partially attributed to habitat change within the coral reef, from more structurally complex corals in the control sites to a replacement of massive bouldering corals in the high-CO2 sites. The loss of structural complexity in the reef meant there were fewer hiding spaces for the zooplankton to seek refuge in during the day. All zooplankton taxa were reduced under high-CO2 conditions but to varying levels, suggesting that each taxon reacts differently to ocean acidification. Since each taxonomic group within the zooplankton communities was reduced to varying levels under ocean acidification, the copepod genus with the largest reduction in abundance was investigated in more detail. Labidocera spp. are pontellid copepods that are generally considered surface-dwellers and are not known to inhabit coral reefs. Therefore, as a preface to the ocean acidification study, the new discovery of these copepods living in coral reefs is first described (Chapter 3). Not only were they found to be residential to the reef, but Labidocera spp. living at the control reefs preferred to reside in coral rubble, macroalgae, and turf algae. Labidocera spp. were one of the most sensitive copepods to high-CO2 conditions and were reduced by nearly 70% in abundance, prompting a more detailed investigation about the effect of ocean acidification on their physiology and habitat preference (Chapter 4). Physiological parameters, e.g. size, feeding, and oocyte development, were unaffected by ocean acidification. Unlike the zooplankton community as a whole, the main cause for the abundance loss of Labidocera spp. was not a shift in the habitat because their preferred substrata were of equal percent coverage across high-CO2 and control sites. Instead, Labidocera spp. were no longer associated with any substrata type. Multiple direct and indirect effects of ocean acidification will act on each zooplankton taxa separately, and their collective response will contribute to the community response. The effects of ocean acidification on zooplankton communities were then scaled up to potential impacts on entire ecosystems. Zooplankton are the primary food source for corals, fish, and other zooplanktivores. The impacts of ocean acidification on zooplankton communities will have cascade effects on the food chain via the pathway of zooplanktivorous organisms. A case study on the stony coral Galaxea fascicularis explored the effects of ocean acidification on the ability of corals, which had lived their entire lives under high-CO2 conditions, to feed on zooplankton (Chapter 5). Under anthropogenic changes, whether it is from bleaching, high turbidity, or ocean acidification, some corals rely more on heterotrophy and consume more zooplankton. Contrary to expectation, this study showed that when given equal quantities of food particles these corals consumed less zooplankton under ocean acidification. Corals rely on heterotrophy for essential nutrients, like nitrogen and phosphorus, which they cannot otherwise obtain from autotrophy and their symbiotic zooxanthellae. In conclusion, my thesis shows that not only is there fewer zooplankton available to consume, but the existing zooplankton is consumed with lower capture rates under high CO2 conditions. Coral reefs in future oceans will likely have reduced zooplankton abundances as an indirect effect of ocean acidification, partially caused by a change in habitat from branching corals to more massive bouldering corals. Zooplankton abundances were reduced yet the community composition was unaffected by ocean acidification. All zooplankton taxa were reduced yet present under high-CO2 conditions suggesting that the zooplankton are at least able to survive under ocean acidification. Fewer zooplankton will be available to zooplanktivores, but the fatty acid content and nutritional value of the zooplankton as a food source is expected to be similar to current food. Together this is expected to negatively impact the entire coral reef ecosystem, with some coral species unable to consume zooplankton at normal rates. In an ecosystem already highly vulnerable to ocean acidification, coral reefs may be even more threatened if the very basis of their food webs is reduced.
75

Coral symbioses under stress: spatial and temporal dynamics of coral-Symbiodinium interactions

Claar, Danielle C. 17 December 2018 (has links)
Coral reefs, the planet’s most diverse marine ecosystems, are threatened globally by climate change and locally by overfishing and pollution. The dynamic partnership between coral and their endosymbiotic algae (Symbiodinium) is the foundation of all tropical reef ecosystems. Symbiodinium provide coral with nutrients for growth, but stress can break down this symbiosis, causing coral bleaching. There are also life-history trade-offs amongst Symbiodinium types - some provide coral with more nutrition, while others are better able to cope with environmental stressors. Although these symbioses are believed to be a critical element of reef resilience, little is known about how local and global stressors alter these partnerships. In this thesis, I combine synthetic literature reviews and a meta-analysis, with field research, molecular analyses, bioinformatics, and statistical analyses to investigate environmentally-driven mechanisms of change in coral-symbiont interactions with the aim of advancing understanding of how corals will adapt to the stressors they now face. First, I conducted a review of coral-Symbiodinium interactions, from molecules to ecosystems and summarized the current state of the field and knowledge gaps. Next, I conducted a meta-analysis of coral bleaching and mortality during El Niño events and created an open-source coral heat stress data product. I found that the 2015-2016 El Niño instigated unprecedented thermal stress on reefs globally, and that, across all El Niño events, coral bleaching and mortality were greater at locations with higher long-term mean temperatures. I provided recommendations for future bleaching surveys, and in a related perspectives piece, highlighted the importance of survey timing during prolonged coral bleaching events. The latter three empirical chapters are based on my six field expeditions to Kiritimati (Christmas Island). Taking advantage of the atoll’s natural ecosystem-scale experiment, I tagged, sampled and tracked over 1,000 corals across its chronic human disturbance gradient. Since corals can uptake Symbiodinium from the surrounding environment, I first investigated the effect of local disturbance and winter storm waves on Symbiodinium communities in coral, sediment, and seawater. Greater variability in Symbiodinium communities at highly disturbed sites suggests that local disturbance destabilizes symbiont community structure. Since local disturbance influences Symbiodinium community structure and coral-associated microbial communities, I next examined the covariance of coral-associated Symbiodinium and microbial communities for six coral species across Kiritimati’s disturbance gradient. Most strikingly, I found corals on Kiritimati that recovered from globally unprecedented thermal stress, experienced during the 2015-2016 El Niño, while they were still at elevated temperatures. This is notable, because no coral has previously been documented to recover from bleaching while still under heat stress. Only corals protected from local stressors exhibited this capacity. Protected corals had distinct pre-bleaching algal symbiont communities and recovered with different algal symbionts, suggesting that Symbiodinium are the mechanism of resilience and that protection governs their communities. Together, this research provides novel evidence that local protection may be more important for coral resilience than previously thought, and that variability in symbiotic and microbial communities provides a potentially flexible mechanism for corals to respond to both local and global stressors. / Graduate / 2019-11-26
76

Coros de empresa como desafio para a formação e a atuação de regentes corais : dois estudos de caso

Teixeira, Lúcia Helena Pereira January 2005 (has links)
Este estudo teve como objetivo geral investigar a formação e a atuação de regentes corais junto a coros de empresa na cidade de Porto Alegre – RS. A investigação procurou responder às seguintes questões: que concepções os regentes têm sobre a prática do canto coral na empresa? Como atuam nesses ambientes? Na opinião dos regentes, que formação e que competências são necessárias para atuarem nesses contextos? Foram realizados dois estudos de caso, tendo como participantes dois regentes de coros de empresa. As técnicas de pesquisa utilizadas foram a entrevista guiada ou focalizada e a observação participada. O referencial teórico fundamenta-se nos conceitos de formação profissional: Le Boterf (2003), Ramalho, Nuñez e Gauthier (2004) e de lazer: Parker (1978), Elias (1992), Dumazedier (1994;1999) e Marcellino (2003). O método de pesquisa empregado foi o estudo multicaso, com abordagem qualitativa. A compreensão dos contextos estudados e de como o ambiente da empresa traz implicações sobre o trabalho dos regentes evidencia a necessidade de se aprofundar as reflexões acerca da formação profissional inicial, levando-se em conta os diferentes campos de atuação.
77

Coros de empresa como desafio para a formação e a atuação de regentes corais : dois estudos de caso

Teixeira, Lúcia Helena Pereira January 2005 (has links)
Este estudo teve como objetivo geral investigar a formação e a atuação de regentes corais junto a coros de empresa na cidade de Porto Alegre – RS. A investigação procurou responder às seguintes questões: que concepções os regentes têm sobre a prática do canto coral na empresa? Como atuam nesses ambientes? Na opinião dos regentes, que formação e que competências são necessárias para atuarem nesses contextos? Foram realizados dois estudos de caso, tendo como participantes dois regentes de coros de empresa. As técnicas de pesquisa utilizadas foram a entrevista guiada ou focalizada e a observação participada. O referencial teórico fundamenta-se nos conceitos de formação profissional: Le Boterf (2003), Ramalho, Nuñez e Gauthier (2004) e de lazer: Parker (1978), Elias (1992), Dumazedier (1994;1999) e Marcellino (2003). O método de pesquisa empregado foi o estudo multicaso, com abordagem qualitativa. A compreensão dos contextos estudados e de como o ambiente da empresa traz implicações sobre o trabalho dos regentes evidencia a necessidade de se aprofundar as reflexões acerca da formação profissional inicial, levando-se em conta os diferentes campos de atuação.
78

Coros de empresa como desafio para a formação e a atuação de regentes corais : dois estudos de caso

Teixeira, Lúcia Helena Pereira January 2005 (has links)
Este estudo teve como objetivo geral investigar a formação e a atuação de regentes corais junto a coros de empresa na cidade de Porto Alegre – RS. A investigação procurou responder às seguintes questões: que concepções os regentes têm sobre a prática do canto coral na empresa? Como atuam nesses ambientes? Na opinião dos regentes, que formação e que competências são necessárias para atuarem nesses contextos? Foram realizados dois estudos de caso, tendo como participantes dois regentes de coros de empresa. As técnicas de pesquisa utilizadas foram a entrevista guiada ou focalizada e a observação participada. O referencial teórico fundamenta-se nos conceitos de formação profissional: Le Boterf (2003), Ramalho, Nuñez e Gauthier (2004) e de lazer: Parker (1978), Elias (1992), Dumazedier (1994;1999) e Marcellino (2003). O método de pesquisa empregado foi o estudo multicaso, com abordagem qualitativa. A compreensão dos contextos estudados e de como o ambiente da empresa traz implicações sobre o trabalho dos regentes evidencia a necessidade de se aprofundar as reflexões acerca da formação profissional inicial, levando-se em conta os diferentes campos de atuação.
79

Coro-cenico : uma nova poetica coral no Brasil

Oliveira, Sergio Alberto de 28 July 2018 (has links)
Orientador: Jose Roberto Zan / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Artes / Made available in DSpace on 2018-07-28T15:20:23Z (GMT). No. of bitstreams: 1 Oliveira_SergioAlbertode_M.pdf: 6415980 bytes, checksum: 2d842258e303f27a45d66b4beaeb5e64 (MD5) Previous issue date: 1999 / Resumo: Está dissertação pretende documentar o processo de criação e sistematização do Coro-Cênico no Brasil, em particular do Estado de São Paulo, através do levantamento e análise do trabalho do Maestro Samuel Kerr e do relato de experiências envolvendo dois grupos corais amadores do interior do Estado. A incorporação da canção de massa no canto coral, assim como a influência dos movimentos artísticos da década de 60, propiciaram a formação do Coro-Cênico em duas modalidades: a modalidade "vanguardista", que surge sob a égide do Movimento Concretista e a modalidade "cancionista", provinda da música popular. Esta última será a mais perscrutada nesta dissertação. Ambas envolvem a questão do hibridismo de linguagens O canto coral, antes uma expressão unidirecional, volta-se agora a uma concepção múltipla de expressão artística, criando outras necessidades técnicas que serão aqui expostas. Juntamente com a discussão teórica acerca da linguagem canção e o seu inter-relacionamento com os coros amadores, descreveremos outras experiências, observando tendências e limites da nova poética / Abstract: This dissertation pretends to document the process of creation, and systematization of de Scenic Choir in Brazil, particularly in São Paulo State, through the gathering and analysis of Maestro Samnei Kerr's work and of report of experiences evolving two amateur choral groups at the São Paulo State's interior. The incorporation of the mass song; in choral singing such as the 60th's artistic movements influence have propitiate the Scene Choir formation in two modalities: the "avant-garde'' modalities, which appears under the Coneretism Movement egis and the "cancionist" modalities, originating from popular music, this dissertation will investigate the last one in more details. Both involve the language hybridism question. The choral singing, previously a unidirectional expression, changes to a multiple conception of artistic expression, creating another technical, necessities here exposed. Associated with the theoretical discussion about the song language and your interrelation with amateur choirs, we'll make a description of another experience observing tendencies and limits of the new poetic / Mestrado / Mestre em Artes
80

The unseen world of coral reefs: impact of local and global stressors on coral microbiome community structure

McDevitt-Irwin, Jamie 04 May 2017 (has links)
Diverse and abundant coral associated microbial communities may play a key role in coral resistance to and recovery from unwavering stressors currently threatening coral reefs worldwide. The composition and structure of the coral microbiome is integral to coral health as microbes can play beneficial (e.g. nutritional or protective) or negative (e.g. pathogenic or opportunistic) roles in the coral. To review the impacts of stressors on the coral microbiome, I compiled data from 39 studies, each tracking microbial community shifts in corals experiencing stress from climate change, pollution or overfishing. Stress was associated with shifts in coral microbial communities. I found that regardless of stressor, microbial alpha diversity increased under stress, with Vibrionales, Flavobacteriales and Rhodobacterales commonly found on stressed corals, and Oceanospirillales not as abundant on stressed corals. In addition, I used 16S rRNA sequencing to evaluate how local and global stressors affect the community structure of the coral microbiome for the two coral species, Porites lobata and Montipora foliosa. I monitored tagged coral colonies at two human disturbance levels (i.e. high and low), before and during a thermal bleaching hotspot at Kiritimati, Kiribati. Human disturbance, a bleaching hotspot, and coral species were all important drivers of coral microbiome community structure. My results suggest that human disturbance increases microbial alpha and beta diversity, although results vary between coral species, with P. lobata having more of a difference between disturbance levels. Similarly, bleaching increased beta diversity at low disturbance sites. Both human disturbance and thermal stress appeared to homogenize coral microbiomes between species and thermal stress appeared to homogenize communities between disturbance levels. Thus, both human disturbance and bleaching appear to stress the coral and destabilize its microbiome. However, intense thermal stress (i.e. 12.86 DHWs) appears to have a greater influence than human disturbance, probably due to corals responding to stressful conditions in a similar manner. In conclusion, my results highlight the impact of local and global stressors on coral microbiome community structure. / Graduate / 2018-04-26 / 0359

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