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Joyce, Karen E. "A method for mapping live coral cover using remote sensing /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18618.pdf.
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Williams, Amanda C. "Mapping land use change as an indicator for live coral cover at Boracay Island Philippines." View electronic thesis (PDF), 2009. http://dl.uncw.edu/etd/2009-1/r3/williamsa/amandawilliams.pdf.
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Brandt, Marilyn Elizabeth. "Coral Disease Epizootiology in the Florida Keys (U.S.A.) and Cayman Islands (British West Indies), and the Development of the Simulation of Infected Corals Model." Scholarly Repository, 2007. http://scholarlyrepository.miami.edu/oa_dissertations/57.
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Understanding coral disease dynamics within the heterogeneous populations in which they act is critical for predicting how the structure of reefs may change as a result of enzootic or epizootic levels of these important sources of mortality. This work focused on combining field studies and the development and testing of a spatially-explicit, individual-based epizootiological computer model with the aim of gaining a greater understanding of the dynamics and impact of white plague, a significant source of mortality on reef-building corals in the Caribbean region. Field studies focused on the incidence and distribution of all sources of coral mortality, including suspect white plague in situ, at two locations; the Florida Keys (United States of America) and Little Cayman Island (Cayman Islands, British West Indies). Results indicated that in both regions disease was the most significant source of mortality during the monitoring time periods, and that suspect white plague type II in Cayman is likely contributing to major structural changes. In Florida, observations made during a mass bleaching event indicated that a significant relationship exists between bleaching severity and disease incidence, and that mortality during the event was largely the result of disease and not bleaching. The simulation model was developed using a long-term data set from Little Cayman, and results of calibration indicated that suspect white plague type II on these reefs is transmissible between colonies within a limited field and require a yearly input from an outside source, and that host susceptibility to infection is low and likely not variable among species. Parameters describing the distribution and composition of the coral population were varied, and results indicated a significant effect of colony density, aggregation, and mean size on the impact of disease. Scenario testing of various disease management strategies indicated that should local prevention measures be developed in the future, it is they, and not treatment, that will likely be the most effective in limiting the impact of disease.
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Slingsby, Shauna N. "Patterns of association and interactions between juvenile corals and macroalgae in the Caribbean /." Electronic version (PDF), 2003. http://dl.uncw.edu/etd/2003/slingsbys/shaunaslingsby.pdf.
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East, Holly Kate. "The evolution of Maldivian coral reef rim islands." Thesis, University of Exeter, 2017. http://hdl.handle.net/10871/30860.
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The first detailed investigation of Maldivian rim island development and reef-to-island connectivity is presented. Study sites were selected on windward and leeward rim aspects of Huvadhu Atoll, and analyses were undertaken at a millennial, contemporary and near-future temporal scales. At millennial temporal scales, contrasting models of island development were presented for the windward and leeward sites. Marked between-site differences were found in the timings of island initiation (2,800-2,000 cal. yr. B.P. and 4,200-3,600 cal. yr. B.P. at the windward and leeward sites respectively). Hence, sea-level does not represent the sole control upon island formation. The period of island initiation and heightened mobility occurred during the mid-Holocene sea-level highstand. Future sea-level rise may thus reactivate the process regime responsible for reef island initiation, potentially inducing further island building and/or heightened island mobilisation. Contemporary analyses highlighted the homogeneity of the sediment reservoir across marine, beach and island sediments. Specifically, sand-grade coral was dominant across all samples within both sites (>50%). The most likely source of sand-grade coral is excavator parrotfish, which was consistent with ecological survey-based estimates of sediment production (excavator parrotfish accounted for 72.8% and 68.2% of sediment production at the windward and leeward sites). The highest sediment production rates were found within the lagoonward environments (59.4% and 75.4% at the windward and leeward sites), which is consistent with the more recent lateral lagoonward mode of island building. With regard to near-future analyses, the apparent recent areal expansion of seagrass beds demonstrated the capacity of ecological changes to cause shifts in sediment production budgets (contributing an additional ~243 tonnes yr-1 of sediment on the leeward rim platform). In addition, significant increases in benthic sediment mobility were found at both study sites under sea-level rise scenarios. Increases in mobility were markedly larger in magnitude at the leeward site than at the windward site. A challenge for the adaptive capacity of atoll nations is thus to acknowledge this atoll-scale diversity in future management strategies.
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Siciliano, Daria. "Latitudinal limits to coral reef accretion : testing the Darwin point hypothesis at Kure Atoll, Northwestern Hawaiian Islands, using new evidence from high resolution remote sensing and in situ data /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2005. http://uclibs.org/PID/11984.
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Suharsono. "Ecological and physiological implications of coral bleaching at Pari Island, Thousand Islands, Indonesia." Thesis, University of Newcastle upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308835.
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Sun, Yali, and 孫亞莉. "Coral Sr, Mg/Sr and Mg/U thermometers and the retrieved SST record forthe last century: a case study using aporites coral from Xisha Island, South China Sea." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31244798.
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Matthews, Elizabeth. "Community-based and collaborative management of coral reefs and coastal resources in Palau /." View online ; access limited to URI, 2007. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/AAI3284827.
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Mason, Benjamin M. "The importance of detritus and microenvironment nutrient enrichment to the growth of coral reef macroalgae, Halimeda and Dictyota /." Electronic version (PDF), 2004. http://dl.uncw.edu/etd/2004/masonb/benjaminmason.html.
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Green, Tamara Kirsty. "Climate change effects on dimethylated sulphur dynamics in tropical coral reef systems." Thesis, University of St Andrews, 2019. http://hdl.handle.net/10023/17135.
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Dimethylsulphoniopropionate (DMSP) and dimethylsulphoxide (DMSO) (collectively DMSP/O) are produced by marine algae, including symbiotic algae within corals. These sulphur compounds are important not only in sulphur cycle dynamics but also in potentially mediating atmospheric conditions, alleviating the effects of climate change and contributing to reef health. Most research has focused on the production of DMSP and its major degradation product, the climatically active gas, dimethylsulphide (DMS) by Acropora corals in the Great Barrier Reef. However, mechanisms for the production and release of DMSP/O by different reef taxa is poorly understood. Recently the importance of mesophotic reefs as refugia for shallow water corals has been postulated, however their role in the marine sulphur cycle is unknown. This research aimed to improve our understanding of the contemporary and climate change induced seawater and tissue production of DMSP/O in a range of reef environments and taxa. This was achieved through a combination of laboratory and field - based studies, using modern and established techniques. An effect of both elevated temperature and OA on increased tissue and seawater concentrations of DMSP/O production is reported in field and laboratory studies. Contrasting effects of benthic cover on tissue DMSP/O distributions and seawater DMSP are also noted. The importance of the physical and hydrodynamic environment on biogeochemical connectivity both within a reef and between neighbouring reefs is also focussed on. Crucially, however, the novel tissue and seawater data from mesophotic sites suggests that deeper reefs could affect the biogeochemistry of their shallow water counterparts. The key finding from this work is that climate change will result in increased seawater DMSP concentrations via two mechanisms; through the increase of cellular production of DMSP/O in all reef taxa, and by increasing the biomass of prolific DMSP producers as reefs transition to a fleshy/macroalgal assemblage. Whilst this could potentially mediate the effects of climate change, it will probably also worsen overall reef health, lead to a restructuring of reef communities from the microbial level upwards and will have possibly permanent and deleterious effects on overall ecosystem function.
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George, Adrienne. "Characterizing Gross Lesions in Corals on Fringing Reefs of Taiwan and Hainan Island, China." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6705.
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Visible lesions on coral colonies are potential indicators that environmental stressors are influencing a reef. To test this hypothesis, pairs of near-shore reefs on Taiwan were surveyed along an anthropogenically influenced gradient that included locations near the cities of Taipei and Taitung, and more remote reefs off Green Island. Two fringing reefs at Sanya, Hainan Island, a popular Chinese resort area, were also assessed. Field surveys were undertaken to detect, quantify and visually describe the occurrence of lesions at each site. Coral mucus samples were collected from both normal-appearing polyps and lesion-afflicted areas of colonies to assess carbon requirements of associated microbes. Tissue samples were also collected to identify bacterial communities inhabiting healthy tissue for comparison with those associated with lesions; denaturing gradient gel electrophoresis and 16S rRNA sequencing for bacterial identification were utilized in these analyses. In addition, tissue samples were collected in the vicinity of lesions and prepared for histological examination.
At sites in Taiwan, lesions were encountered twice as often at the sites near Taipei and Taitung than at Green Island. The fewest (15/72 sightings) lesions were encountered at the reefs near Sanya, primarily because there has been nearly an 80% loss of coral cover at Sanya in recent decades. Overall, tissue loss was the most common lesion recorded (52%), followed by pink discoloration (27%) and color loss (i.e., bleaching, 15%). Porites was the taxon most commonly observed with one or more lesions (45% of sightings). Microbes within mucus from lesioned areas utilized similar carbon sources as microbes from mucus from healthy polyps, but utilized those sources more than twice as often. Examples of carbon sources utilized by microbes in >50% of the lesion samples were D-cellobiose, D-mannitol, N-acetyl-D-glucosamine, alpha-cyclodextrin, and glycogen. Bacterial assemblages on corals were significantly different between Taiwan and China, among sites, and between water samples and coral samples, but not between healthy samples and lesions. Bacterial sequences identified in tissue samples from lesions revealed the presence of well-known disease-related genera, such as Clostridium and Vibrio. Microbes specifically indicating anthropogenic sources, included Bacillus sp. (sewage sludge) and Geobacillus thermolevorans (irritable bowel syndrome). Histological examination of tissue samples, particularly those from lesions characterized as tissue loss, revealed fragmentation and detachment from the mesoglea of gastrodermis and epidermis, as well as brown granular material, and the presence of ciliates and small crustaceans.
Corals are susceptible to a variety of diseases. For reefs in the western Atlantic and Caribbean, occurrences of lesions and characterization of coral diseases have been relatively well documented. In contrast, many areas in the vast Indo-Pacific, including the reefs of Taiwan and China, have received much less attention. This study of lesions and associated microbiomes on nearshore reefs of Taiwan and Hainan Island supports previous research that has revealed higher incidences of coral lesions and disease in reefs near extensive human populations. The results also support the hypothesis that many of the microbes associated with coral lesions are part of the natural coral microbiome and that some microbes can become opportunistic when the host corals are stressed.
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Morris, Annalie. "Coastal habitat use by juvenile coral reef fish in the British Virgin Islands." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427851.
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Schlaerth, Hannah L. "Remote Sensing of Water Quality Parameters Influencing Coral Reef Health, U.S. Virgin Islands." Kent State University Honors College / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1525710103251186.
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Cannon, Sara E. "Investigating human impacts to coral reefs in the Republic of the Marshall Islands." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/62564.
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Both local and global threats are affecting the health of coral reefs worldwide. In addition to endangering the livelihoods and source of food for millions of people, threats to coral reefs may result in flattening reefs, which reduce habitat complexity and the ability of reefs to protect shorelines from erosion. This could be particularly detrimental to low-lying Pacific atolls like those found in the Republic of the Marshall Islands (RMI). I examined the influence of local human disturbance and heat stress on coral and algal community composition in Majuro and Arno Atolls in the RMI to explore how human disturbance affects coral and algal communities, and how to best characterize those communities. With a population of approximately 30,000 people, Majuro is home to the largest population of all of the RMI's 29 atolls and underwent extensive human modifications after American occupation during World War II. By contrast, Arno is home to fewer than 2,000 people and has remained relatively undisturbed. In June of 2016, I conducted benthic surveys at 25 sites along a gradient of human impacts across the two atolls. At each site at 10m depth, I measured percent cover of coral and algae genera and size-frequency of coral. I also utilized limited historical data to explore how reefs had recovered after a thermal stress event in 2014. In order to estimate human disturbance, I used the mean normalized difference vegetation index (NDVI) of the nearby coastline, which measures vegetation intensity. The coral and macroalgae composition of sites differed by atoll, mean NDVI, and wind and wave exposure, but not by sea surface temperature. The most degraded sites had low macroalgae cover and were dominated by turf algae, sponges, and cyanobacteria. One genus of macroalgae, Halimeda, was associated with sites that had low disturbance, while another, Hypnea, was correlated with higher disturbance. These results suggest that using macroalgae as an indicator of degradation may mask the influence of local human disturbance on reef community composition. Instead, it is important to consider identifying other indicator taxa and to measure coral and macroalgae cover to at least the genus level.Arts, Faculty of
Geography, Department of
Graduate
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Edinger, Evan Nathaniel. "Effects of land-based pollution on Indonesian coral reefs : biodiversity, growth rates, bioerosion, and applications to the fossil record /." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0005/NQ42843.pdf.
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Hagman, Derek Kristian. "Reproductive dynamics of coral reef biota at the Flower Gardens /." Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3008347.
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Hime, Stephanie Patricia. "The Effect of Marine Based Tourism on the Coral Reefs of the British Virgin Islands." Thesis, University of East Anglia, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490594.
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Coral reef resources are under threat globally from liuman-induced changes including; development, pollution, fishing, over-use and climatic change. Here I consider the ecological and economic effects of the scuba diving and snorkelling industries on the coral reefs of the British Virgin Islands (BVI). I begin examining the current ecological impacts of scuba diving and snorkelling across reefs in the BVI; I also look at diver behaviour, and the recovery of hard corals following exposure to diver damage. The intensity of dive and snorkelling use currently appears sustainable. However, there are several sites based on wrecks that are subject to extremely high levels of use, thus the benthic organisms situated at these sites are under significantly greater levels of stress than those situated at other sites. All corals monitored following simulated diver damage showed rapid recovery. However, there were differences in recovery times between hard coral species and types of damage. Coral reef ecosystems are particularly important to the economies of many island nations and help attract tourists as well as providing the basis for excursion industries such as scuba diving and snorkelling. In the later chapters of this thesis I focus on the current and potential value of coral reefs to the BVI by conducting several choice experiments with visual aids. I found a significant consumer surplus related to the guided scuba diving and snorkelling industries of the BVI, both of which were influenced by changes in environmental quality. Finally, ecological and economic methodologies were applied to a specific ecosystem threat. I used the 2005 Caribbean wide bleaching as an example of a catastrophic event experienced by the reefs of the BVI. The ensuing economic and ecological losses were measured and found to be significant. These results demonstrate the strength of a combined ecological and economic approach to reef management.
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Hendrickson, Katharine Jane. "Changes in Coral Community Composition at Devil's Crown, Galapagos Islands, Ecuador: A 7,700 Year Perspective." NSUWorks, 2014. http://nsuworks.nova.edu/occ_stuetd/29.
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Coral mortality caused by El Niño–Southern Oscillation (ENSO) activity and its related disturbances has been researched throughout the Eastern Pacific. In the past three decades, disturbances related to the El Niño–Southern Oscillation (ENSO) have been shown to influence coral growth in the Eastern Pacific. In the Galápagos Islands, Ecuador, more than 97% of corals experienced mortality after the severe 1982-1983 ENSO episode. However, two of the most dominant coral species found in a coral community adjacent to Devil’s Crown; Psammocora stellata and Diaseris distorta survived this severe ENSO event. By reconstructing sediment cores of the coral community, this study assessed how the coral assemblage has changed over the past 7,700 years of the Holocene epoch. The historical reconstructions were then related to existing records of Holocene ENSO variability in order to determine if changes in the relative abundance of coral species were related to ENSO activity and disturbances. We observed high variability in the relative abundances of P. stellata and D. distorta in the cores, including an increase in the abundance of D. distorta at approximately 2,200 yBP. Between the two species, opposite abundance trends were observed and supported by Detrended Correspondence Analysis (DCA) and Non-metric Multidimensional Scaling (NMDS) ordination analysis. Overall, the high variance in coral composition at the site throughout the Holocene documents repeated disturbance events in this region.
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Edwards, Peter E. T. "Measuring the recreational value of changes in coral reef ecosystem quality in Jamaica the application of two stated preference methods /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 310 p, 2009. http://proquest.umi.com/pqdweb?did=1818417431&sid=4&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Kersting, Diego K. "Ecology and conservation of the Mediterranean endemic coral Cladocora caespitosa = Ecología y conservación del coral endémico del Mediterráneo Cladocora caespitosa." Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/132996.
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Marine ecosystems are declining worldwide threatened by an increasing number of stressors. Global change-related disturbances have highlighted the need of new complementary conservation measures; for which the knowledge on the affected species, communities and impacts is essential. The species objective of this PhD, the Mediterranean endemic coral Cladocora caespitosa, may serve as a case study of those species that even if seriously threatened, are lacking essential information on key ecological processes and the responses to the rapid environmental changes that are happening globally.
Cladocora caespitosa is the only colonial and zooxanthellate scleractinian coral endemic to the Mediterranean Sea. It is a long-lived and ecosystem engineer species, being one of the rare examples of this type of organisms found in shallow Mediterranean communities, and constitutes an invaluable natural patrimony due to its extensive ancient history, its sizeable long-lasting structures and its fragility in the actual context of climate change. Currently, large C. caespitosa bioconstructions are scarce and only a few examples are known, i.e., in Mjlet National Park (Adriatic) or in the Columbretes Islands (NW Mediterranean).
The extensive field of colonies and reefs found in the Illa Grossa Bay (Columbretes Islands Marine Reserve) shows a cumulative colony cover of 2900 m2. This population displays a high degree of geographical isolation and its spatial distribution in the bay is highly aggregated. Our results showed that Cladocora caespitosa is a slow growing species (~ 2.5 mm yr-1), with low recruitment and natural mortality rates (~ 0.30 recruits m-2 yr-1 and 1 %, respectively). Strikingly, the obtained results on the reproductive traits of this species differed significantly between Western Mediterranean and Adriatic Seas. Cladocora caespitosa is gonochoric in W Mediterranean, showing a water temperature-associated gonadal cycle that culminates at the end of the summer in contrast to the findings in the Adriatic, where the coral has described as hermaphroditic with the spawning occurring at the beginning of the summer.
Global change is rapidly altering Mediterranean marine habitats, primarily through warming and the invasion of new species. The C. caespitosa population in the Illa Grossa Bay suffered mortalities after 9 summers, separated into 2 mortality periods (2003 - 2006 and 2008 - 2012).
The highest necrosis rates were recorded during the first mortality period, after the exceptionally hot summer of 2003. Over 50 % of the area covered by C. caespitosa has
suffered necrosis after these recurrent mortalities, which were significantly related to warming (summer warming trend: 0.06 °C yr-1). The differences in necrosis found after summers with similar thermal anomalies pointed out to the existence of other acting factors probably related to the interannual temperature context and delayed stress after extreme summers. These results show that while Cladocora caespitosa displays great ecological plasticity, mostly in relation to changing light conditions, it is not adapted to endure the extreme changes in temperature driven by climate change, the most worrying threat for this coral.
Regarding to the impact of invasive species, the invasive algae Lophocladia lallemandii and Caulerpa racemosa successfully spread over the Illa Grossa Bay from 2006 to 2012 and overlapped their distribution in the bay with that of C. caespitosa. No lethal effects of the invasive algae were detected on the coral colonies, which showed toxic activity. This may explain the low overgrowth of living colony parts by C. racemosa and the ability of this coral to compete in an algal dominated community.
In long-lived corals such as C. caespitosa, recovery from mortalities relies mostly on recruitment, but there are two main obstacles that may compromise recovery. Firstly, the high frequency of mortalities detected during the last decade probably exceed the recovery potential of the low recruitment rates. Secondly, both warming and invasive algae may have delayed and synergetic effects on reproduction, recruitment and juvenile survival.
All the results obtained highlight the endangerment of this species facing rapid environmental changes. Cladocora caespitosa is listed in the IUCN Red List of Threatened Species as Data Deficient. However, the information obtained in this PhD points out that this species could meet the criteria to fall into a threatened category.Los ecosistemas marinos están siendo amenazados por un número cada vez mayor de impactos. Entre ellos, los impactos derivados del cambio global han puesto en relieve la necesidad de nuevas medidas de conservación que puedan complementar a las ya existentes. Sin embargo, su desarrollo requiere un amplio conocimiento de las especies, procesos e impactos implicados. Esta tesis se centra en la adquisición de nuevos conocimientos sobre la biología y ecología del coral Cladocora caespitosa con el objetivo de aportar información útil para su conservación. Los resultados obtenidos pueden servir como guía para la conservación de aquellas especies de características parecidas sobre las que no se tiene información. Esta especie es el único coral escleractinio, colonial y zooxantelado, endémico del Mediterráneo. Se trata de uno de los pocos ejemplos de especie longeva y estructural que se encuentra en las comunidades mediterráneas de aguas someras. La Bahía de L'Illa Grossa (Reserva Marina de las Islas Columbretes) alberga una de las poblaciones más importantes de este coral, con campos de colonias y arrecifes que muestran una superficie acumulada de 2900 m2. Los resultados obtenidos muestran que se trata de una especie de lento crecimiento, con bajas tasas de reclutamiento y mortalidad natural y que muestra importantes divergencias en sus características reproductoras entre el Mediterráneo Occidental y el Adriático. La población de C. caespitosa de Columbretes ha sufrido mortalidades recurrentes asociadas al calentamiento del agua, que han afectado a más de la mitad del área ocupada por este coral en la bahía. Por otra parte, las algas invasoras Lophocladia lallemandii y Caulerpa racemosa han invadido exitosamente la Bahía de L'Illa Grossa, solapando su distribución con la de C. caespitosa. De momento, no se han observado efectos letales de estas algas sobre el coral; sin embargo, se ha podido detectar la actividad tóxica de esta especie, que podría explicar el bajo recubrimiento de sus partes vivas por C. racemosa. El potencial de recuperación de esta población es limitado dado el bajo reclutamiento y la frecuencia e intensidad de las mortalidades. Además, no se pueden descartar efectos subletales del calentamiento y las algas invasoras sobre la reproducción, reclutamiento y la supervivencia de los juveniles. A partir de esta información esta especie podría cumplir los criterios de la UICN para ser catalogada como especie en peligro.
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Bythell, J. C. "A nitrogen budget for the Caribbean elkhorn coral Acropora palmata (lamarck) from the back-reef environment of Tague Bay reef, St. Croix, U.S. Virgin Islands." Thesis, University of Newcastle Upon Tyne, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383984.
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Freitas, JoÃo Eduardo Pereira de. "Ictiofauna do parque estadual marinho da Pedra da Risca do Meio (Cearà - Brasil): composiÃÃo, estrutura e contexto biogeogrÃfico." Universidade Federal do CearÃ, 2009. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=12906.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorAs assembleias de peixes em ambientes recifais estÃo entre as mais diversas dos oceanos, sendo o estudo destes animais indispensÃvel para um melhor entendimento do ecossistema como um todo. Recentemente foi publicado um volume considerÃvel de trabalhos a respeito da ictiofauna recifal brasileira. Contudo, algumas regiÃes, como o estado do CearÃ, apresentam grande carÃncia de informaÃÃes bÃsicas. A presente pesquisa encontra-se dividida em dois tÃpicos principais, sÃo eles: 1. Estruturas das assembleias de peixes em trÃs ambientes recifais do Parque Estadual Marinho da Pedra da Risca do Meio (PRM), 2. Uma anÃlise zoogeogrÃfica dos peixes em ambientes recifais do Nordeste brasileiro. Para discutir ambos os assuntos, foram utilizados dados qualitativos (listas das espÃcies) e quantitativos (abundÃncia das espÃcies) obtidos em aproximadamente 210 mergulhos autÃnomos (SCUBA) em 13 ambientes recifais da costa cearense entre 16 e 35 metros de profundidade. As amostragens quantitativas foram realizadas em trÃs ambientes recifais dentro do PRM (Pedra Nova, Risca, AviÃo) entre outubro de 2002 e setembro de 2003 e foram baseadas em 63 censos visuais estacionÃrios, 21 em cada ponto. Para o PRM foram inventariadas 129 espÃcies de peixes sendo 6 elasmobrÃnquios e 123 teleÃsteos. Baseado em registros fotogrÃficos, foi elaborado um guia preliminar contendo 83 espÃcies de peixes do PRM. Foram registradas nos censos 11.140 ocorrÃncias de peixes sendo: 4.755 na Pedra Nova, 2.222 na Risca e 4.163 no AviÃo. As trÃs assembleias analisadas apresentaram padrÃes de ictiofauna significativamente diferenciados que provavelmente estÃo relacionados Ãs peculiaridades ambientais de cada local. TambÃm foram constatadas diferenÃas significativas nas assembleias dos trÃs locais, entre os dois perÃodos climÃticos existentes na regiÃo (seco e chuvoso). A anÃlise zoogeogrÃfica comparou ambientes recifais do CearÃ, Parcel do Manuel LuÃs (MaranhÃo), Risca do Zumbi (Rio Grande do Norte) ParaÃba (PA), Abrolhos (Bahia) e as ilhas oceÃnicas Atol das Rocas e ArquipÃlago de SÃo Pedro e SÃo Paulo. Foi observado que a composiÃÃo da ictiofauna recifal do Cearà apresenta considerÃvel semelhanÃa as dos estados prÃximos (Rio Grande do Norte e ParaÃba). Alem disso, os ambientes recifais continentais da regiÃo nordeste do Brasil suportam um nÃmero semelhante de espÃcies.
Meetings of fish in reef environments are among the most diverse of the oceans, and the study of these essential for a better understanding of the ecosystem as a whole animal. Recently published a considerable volume of studies regarding the Brazilian reef fish populations. However, some regions, such as the state of CearÃ, show great lack of basic information. This research is divided into two main topics are: 1. Structures of the Assemblies of fish in three reef environments of Pedra da Risca do Meio State Marine Park (PRM), 2. A zoogeographical analysis of fish in reef environments Northeast Brazil. Were used qualitative data (list of species) and quantitative (species abundance) obtained in approximately 210 scuba dives (SCUBA) in 13 reef environments of Cearà coast between 16 and 35 feet deep to discuss both matters. Quantitative samples were taken from three reef environments within the PRM (New Stone, Risca, Airplane) between October 2002 and September 2003 and were based on stationary visual census 63, 21 in each point. PRM to 129 species of fish and 6 elasmobranch and teleost 123 were inventoried. Based on photographic records, we designed a preliminary guide containing 83 fish species from the PRM. 11,140 occurrences of fish were being recorded in the censuses: 4755 New Stone, in 2222 and 4163 in Risca Airplane. The three assemblies analyzed showed significantly different patterns of fish populations that are probably related to the environmental characteristics of each site. Significant differences were also found in the assemblies of the three sites, existing between the two climatic periods in the region (dry and wet). A zoogeographical analysis compared reef environments of CearÃ, Parcel Manuel LuÃs (MaranhÃo), Risca Zombie (Rio Grande do Norte) ParaÃba (PA) Abrolhos (Bahia) and oceanic islands Archipelago and Rocas Atoll St Peter and St Paul . It was observed that the composition of the reef fish fauna of Cearà has considerable similarity to the nearby states (Rio Grande do Norte and ParaÃba). Moreover, the continental reef environments of northeastern Brazil support a similar number of species.
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Morris, Tamaryn. "Physical oceonography of Sodwana Bay and its effect on larval transport and coral bleaching." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/2038.
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Thesis (MTech (Oceanography))--Cape Peninsula University of Technology, 2009A collaborative study between Marine and Coastal Management (MCM) and the Oceanographic Research Institute (ORI) was initiated in March 2001 to investigate the physical oceanography of Sodwana Bay, South Africa, and the affects on coral communities resident to the area. A bottom-mounted Acoustic Doppler Current Profiler (ADCP) and three Underwater Temperature Recorders (UTR) were deployed to complement the long-term monitoring UTR deployed on Nine-Mile Reef (NMR) in 1994. The study was terminated after 30 months, whereby all instruments were removed except for the long-term monitoring UTR.
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Sulu, Reuben John. "Multidisciplinary appraisal of the effectiveness of customary marine tenure for coral reef finfish fisheries management in Nggela (Solomon Islands)." Thesis, University of Newcastle upon Tyne, 2011. http://hdl.handle.net/10443/1327.
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The failure of centralised fisheries management systems to prevent the overexploitation of coral reef resources has led many scholars and conservation practitioners to promote the use of customary marine tenure (CMT) as an alternative devolved means of fisheries management. The effectiveness of CMT for fisheries management is debated; some scholars argue that CMT is embedded within particular historical, socio-economic and political contexts and that unless it evolves to changing circumstances, its effectiveness for fisheries management will wane under external influences and changing exploitation patterns. Each CMT regime is unique; hence its response to changing circumstances may vary. A better understanding of the circumstances under which a CMT regime is likely to succeed is important if it is to be effectively used for fisheries management. This research is posited on the DPSIR (Driver, Pressure, State, Impact, Response) model and employs multidisciplinary methods to investigate the effectiveness of CMT for reef finfish fisheries management. The aims of this thesis are: (1) To investigate the role of markets and subsistence as driving factors for fishing; (2) To investigate fisher spatial allocation of fishing, methods and target taxa (as proxies for pressure and impact); (3) contribute to the biological knowledge of a prominent vulnerable species (Plectropomus leopardus) by investigating aspects of its demography and reproduction (as a proxy for state); and (4) Investigate relationships between the Nggela CMT governance system and modern governance system (as a proxy for response), to improve understanding of how this knowledge may be applied to enhance small-scale fisheries management. The role of markets and subsistence as driving (D) factors for fishing was investigated using the sustainable livelihoods approach (SLA). Ninety three (43 from the western zone and 50 from the eastern zone) household surveys were conducted in 10 (5 from the eastern zone and 5 from the western zone) randomly selected villages in Nggela to determine the contribution of different livelihood activities to fisher livelihoods. The reason for comparing the eastern and western zone was to determine the role of available natural land capital as one contributing factor (besides markets) to fishing drivers. Quantitative data generated from the household surveys were analysed using the statistical package SPSS. Additional key informant interviews to generate qualitative data to support the quantitative data were also conducted. Spatial allocation of fishing and target taxa was investigated using household surveys (the same household survey mentioned above but with questions to address the issue of spatial allocation and fishing methods used), participative fishing with fishers to confirm spatial allocation of fishing and fishing methods employed and recording of landings data to determine the types of fish taxa targeted. One of the initial aims of studies on P. leopardus was to compare the age-based demographic parameters of P. leopardus between CMT areas and offshore sub-tidal areas, the hypothesis being that if CMT was effective agebased demographic parameters would reveal the non vulnerability of P. leopardus in CMT areas. Such a comparison was not possible as only 4 specimens were obtained from inshore CMT areas compared to 116 specimens from offshore sub-tidal reefs. To determine the age-based demographic parameters of Plectropomus leopardus, fish total lengths (mm) and otoliths of fish were collected in the field, this was followed by otolith annuli counts of ages (tagged to a particular fish of certain total length) at the laboratory. A von Bertalanffy growth curve was then fitted to the fish total length data and to the age data to determine asymptotic length, Brody growth coefficient and theoretical age at length zero. Total mortality rate was determined by generating catch curves where the frequency of fish in each age class was regressed against age. Longevity was determined by calculating the mean age of 10% of the oldest individuals. Demographic parameters of P. leopardus in Nggela were also compared to those of Australian locations to determine variations in age-based demography. Data analysis of P. leopardus data was done using the statistical software R and Microsoft Excel 2003. Reproductive aspects of P. leopardus were determined from the fish gonads collected from the field. Fish gonads were used to determine different sexual reproductive stages. Data on the different sexual reproductive stages was used to determine sexual maturity and sex change. The relationship between CMT governance and modern governance and how they may be combined for an effective reef finfish fisheries management was investigated using literature research, key informant interviews and dynamite fisher interviews. Investigations of livelihoods show that Nggela fishers were engaged in more than one livelihood activity for their livelihoods. Subsistence gardening was the most important livelihood activity. While finfish was important for subsistence purposes, accessible markets and the role of middlemen in the villages made it especially important for income generation. A comparison of the role of fishing between eastern and western zone showed that available natural land capital was also an important driver for fishing; fishing was higher in the western zone where there was a narrow natural land capital. Fisher perceptions indicate a declining trend in fisheries resource abundances within CMT areas; such decline has resulted in changes in the spatial allocation of fishing with a shift in fishing to offshore sub tidal reefs. Although some spatial closures were observed, fishing within the CMT areas is flexible. Three MPA’s currently existed in West Nggela and fishing prohibitions within the areas were observed mainly because people thought that the MPA’s were underscored by the government. Line fishing from dugout canoes remains the main method of fishing. Median trophic level of fish catch was between 2 - 3.84 while median standard length of catch was between 19 - 24 cm. Age-based demographic studies show that the Brody growth coefficient of Nggela P. leopardus was 0.13 yr-1, longevity was 12.9 years, maximum age was 15 years and mortality rate was 0.22% yr-1. Female sexual maturity of Nggela P. leopardus began at 2 years of age with 50% sexual maturity achieved at 3.22 years. Sexual transition from female to male began at 3 - 10 years of age with 50% sex change achieved at 11 years. Mature female to male ratio was 3:1. The age-based demographic parameters of P. leopardus in Nggela were similar to those in Swain and Lizard Island in Australia. For Swain reef, growth coefficient was 0.17 yr-1, longevity was 10.1 years, maximum age was 14 years and mortality rate was 0.39% yr-1. For Lizard Island, growth coefficient was 0.26 yr-1, longevity was 7.2 years, maximum age was 10 years and mortality rate was 0.59% yr-1. Age-based demographic parameters of P. leopardus in Nggela were different to locations in Western Australia – Scott and Abrolhos reefs. For Scott reef, growth coefficient was 0.42 yr-1, longevity was 6.4 years, mortality rate was 0.30% yr-1 while the maximum age was 8 years. For Abrohlos reef growth coefficient was 0.08 yr-1, longevity was 13 years, mortality rate was 0.24% yr-1 and maximum age was 18 years. Sea temperature may be one contributing factor to regional variations in age-based demographic parameters. The current CMT governance system has undergone changes which has rendered it ineffective as a coercive force for reef finfish fisheries management. While CMT is recognised by the modern governance system through National legislations, necessary ordinances at the provincial level are absent which prevent the effective use of CMT for fisheries management. For CMT to be effective it requires empowerment at the provincial government level.
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Kilbourne, Kelly Halimeda. "A Coral Window on Western Tropical Pacific Climate during the Pleistocene." [Tampa, Fla. : s.n.], 2003. http://purl.fcla.edu/fcla/etd/SFE0000107.
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Marsters, Teuvirihei Helene. "Beach stability on a tropical uplifted coral atoll : Niue Island : a thesis submitted to the Victoria University of Wellington in fulfilment of the requirements for the degree of Master of of Science (Hons) in Physical Geography /." ResearchArchive@Victoria e-Thesis, 2009. http://hdl.handle.net/10063/1216.
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Brown, Kathryn. "Population Fluctuation of the Nodular Coral Psammocora stellata in the Galápagos Islands, Ecuador: An Indicator of Community Resilience and Implications for Future Management." NSUWorks, 2016. http://nsuworks.nova.edu/occ_stuetd/405.
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Corals are experiencing a worldwide decline in abundance and diversity. Reasons for this include anthropogenic impacts and associated changes to environmental conditions, including global climate change. Increasing atmospheric CO2 levels lead to a coordinated increase in sea surface temperatures and decrease in oceanic pH. Warming events associated with El Niño-Southern Oscillation (ENSO) amplify the impacts of steadily increasing temperatures. For example, coral communities in the Galápagos Islands experienced mortality rates of up to 95-99% during severe ENSO warming in 1982-1983. Persisting through such extreme conditions imposes additional challenges to survival in already marginal environments for coral growth and development that occur in the eastern tropical Pacific. This study quantifies via photoquadrats population changes in mean live coral cover, density, and colony size over a 7-year period (2004-2011) in a small community of the nodular coral Psammocora stellata located at Xarifa Island in the Galápagos Islands. The physical characteristics of this shallow (1-3 m depth) habitat include shading by tall basalt cliffs and strong water flushing action that may contribute to the persistence of this species at this atypical locality through mitigation of anomalously warm and cold conditions.
Coral cover is high for this region, and significantly increased from 39.7% in 2004 to 58.3% in 2011 (p=0.006, Tukey HSD), an overall increase of 47%. Fluctuations in coral cover were associated with anomalous temperatures (up to +3.5° and -4.6° C compared to daily means). Negative temperature anomalies in 2007 were associated with a non-significant decrease in coral cover (55.3% in 2007 to 49.5% in 2009), and coral cover rebounded in 2011 to 58.3%. From 2004 to 2011 colony density increased significantly, from 258±62 to 612±245 colonies m-2 (p2 (pin situ, documenting values that ranged from 16.8° - 28.9° C. The persistence of the Psammocora community through both strong and moderate ENSO events demonstrates the resistance and resilience of the species to these temperature anomalies. Adding to the understanding of this species and its interactions with the surrounding physical processes will aid in the development and improvement of management strategies.
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Lovenburg, Vanessa. "Omnifarious octocoral observations : ecology and genetics of octocoral communities from Útila, Bay Islands, Honduras." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:ba3d9aae-77ce-42a6-9de2-7235a57637f6.
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The Oxford English Dictionary defines 'omnifarious' as 'comprising or relating to all sorts or varieties', which quite accurately captures the very nature of octocorals and this thesis. The research reported here, aims to describe undocumented communities of coral reef organisms - the octocorals - which are an emergent dominant component within their threatened ecosystem of the Caribbean. Within the last four decades, coral reefs worldwide have experienced a precipitous plunge in many ecosystem services they provide, and most notably in the Caribbean. The foundation to reef resilience is structured on the ecosystem's ability to repair and restructure itself in the face of environmental shifts. These intricately complex strategies of resilience depend on repair mechanisms provided by a source of biodiversity, much of which remains poorly understood. This work explores many facets of the functioning within this potential future coral reef ecosystem. These reports are one of the most significant contributions to documenting and describing octocoral biodiversity (e.g. species, genetic, and community diversity) of the wider ecoregion of the Mesoamerican Barrier Reef System within the last three decades.
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Singh, Abhinav. "Aggregation in the Schelling model and inverted biomass pyramids in ecosystems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29606.
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Thesis (Ph.D)--Physics, Georgia Institute of Technology, 2009.Committee Chair: Weiss, Howard; Committee Member: Cvitanovic , Predrag; Committee Member: Goldman, Daniel; Committee Member: Schatz, Michael; Committee Member: Wiesenfeld, Kurt. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Hayden, Jason. "A multi-species mariculturesystem : a holistic approach to ornamental culture." Thesis, Cape Peninsula University of Technology, 2010. http://hdl.handle.net/20.500.11838/2034.
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Thesis (MTech (Oceanography))--Cape Peninsula University of Technology, 2010Coral reefs are in a worldwide state of crisis due to overexploitation. One of the factors contributing to the over exploitation is the marine ornamental industry. This industry utilises a diversity of organisms, comprising approximately 1470 species of fish and more than 300 species of invertebrates. Between April and December 2007, five of the 18 companies who had import permits for South Africa, imported a total of 359 different ornamental species, 252 of these were fish species while the remaining 107 species were invertebrates. During these nine months a total of 32 005 individual organisms were imported into South Africa by the five companies. There were two groups of fish that represented the highest import volumes. These were Amphiprion spp. and Pomacentradae spp., as well as the Gobidae spp. These groups represented 38% and 19% respectively of the total number of fish imported" Aquaculture has the potential to substantially reduce the harvesting pressure on coral reef organisms globally. A small-scale multi-species mariculture system was designed and constructed for benthic egg-laying species of fish (brood stock), corals, and ornamental algae. The system was designed to be low cost and easy to operate. The total capital costs for the system was R15 680.70. In order to estimate the potential yield of an aquaculture facility it is important to know the growth rate of the proposed species under pilot conditions. The use of artificial lighting regimes in aquaculture comes at a financial cost. It is for this reason that it is important to know what lighting scenario yields the highest growth rate of corals. The effects of photoperiod were tested on Sinularia sp. of coral. Two photoperiods were tested, namely: Groups (8:16 h Iight:dark cycle) and Group12 (12:12 h light:dark cycle). No significant difference in weight was found between Group8 and Group12 (p = 0.975). There was however a significant increase (p = 0.002) in Surface-area Pixel Value (SPV) for Groups (1996.73 millipixels pixel-1 day -1) compared to Group12 (983.73 millipixels pixel-1 day -1). The use of a 8:16 h lightdark cycle can thus yield coral of a larger size but not necessarily a higher mass.
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Pickard, Alexandra E. "Characterization of Shark Movements on a Mesophotic Caribbean Coral Reef and Temporal Association with Fish Spawning Aggregations." NSUWorks, 2013. http://nsuworks.nova.edu/occ_stuetd/11.
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Habitat use of mesophotic coral reefs by sharks is largely unknown. However, it is well established that mesophotic reefs are the site of spawning aggregations for many species of teleost fish. These aggregations represent seasonal concentrations of potential prey biomass that may influence the habitat use of predatory species such as large sharks. I employed acoustic monitoring to examine the movements of three shark species [lemon shark (Negaprion brevirostris), tiger shark (Galeocerdo cuvier), and Caribbean reef shark (Carcharhinus perezi)] to determine 1) the comparative spatiotemporal patterns of mesophotic reef habitat use by the three shark species and 2) the spatiotemporal relationship between these sharks and grouper spawning aggregations at a fish spawning aggregation (FSA) site (Hind Bank and Grammanik Bank) along the southern reef shelf edge off St. Thomas, United States Virgin Islands (USVI). Tiger and lemon sharks were detected across nearly the entire acoustic array, which spanned ~ 1060 km2. When present, Caribbean reef sharks used a much smaller activity space, composed exclusively of mesophotic reef habitat located within FSA sites. Individuals from all three species were typically detected for stretches of several consecutive days, while periods without detections usually lasted less than one week. Lemon sharks were present at the FSA site more often during the grouper spawning season (Dec-May) than the non-spawning season (Jun-Nov), but showed no preference toward specific areas within the FSA site, which varied by location and grouper species composition. In contrast, there was no relationship between the presence of tiger and Caribbean reef sharks at the FSA site and the grouper spawning season. My results suggest that despite different habitat use 5 patterns and varying degrees of fidelity, this mesophotic reef serves as an important habitat to all three shark species.
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Rahman, Ridzwan Abdul. "Recovery processes of coral communities following the crown-of-thorns starfish, Acanthaster planci, infestations on the east coast islands of peninsular Malaysia." Thesis, University of Newcastle Upon Tyne, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283767.
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Paul, Nicole Christine. "Variable Recovery of the Massive Coral, Porites Lobata, in Response to El Nino-Southern Oscillation Events at Devil's Crown, Galapagos, Ecuador." NSUWorks, 2012. http://nsuworks.nova.edu/occ_stuetd/93.
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Porites lobata is an important reef building coral in the tropical eastern Pacific and the dominant Porites species in the Galápagos archipelago. Following the 1982-83 El Niño-Southern Oscillation the Galápagos Islands experienced 97-99% coral mortality, leaving many areas throughout the archipelago denuded of corals. Because very few long term assessments have been conducted on the growth and resilience of P. lobata to natural disturbances in the Galápagos Islands (Glynn et al., 2001; Glynn et al., 2009), benthic surveys were performed on a uniquely dense aggregation of P. lobata colonies at Devil’s Crown, Floreana Island between 1993 and 2011. Annual changes in live tissue area were calculated for the majority of the population (n=17) using Coral Point Count with Excel extensions (CPCe 3.6) software to determine growth and recovery trends for this aggregation. Total live tissue area (n=10) increased from 1993 to 2011, however due to high interannual variability this increase was not significant. Within this overall pattern, a general trend of decline was observed in live tissue cover from 1993 to 2000, with increases in tissue area observed from 2000 to 2011. Severe bleaching (85-100%) was observed during the 1998 survey, followed by 42% tissue loss (n=10), coinciding with sea water warming associated with the very strong 1997-1998 El Niño-Southern Oscillation event. Subsequent regrowth of coral tissue was observed during the 2001 survey with continued recovery through 2009. Multiple comparison testing revealed a significant difference between the impacted state (1999) and the recovered state (2009), (p = 0.002, Dunn’s method, n=17), suggesting this aggregation required a period of ten years to recover from this disturbance. During this recovery period the moderately strong 2007-2008 La Niña, with accompanying stressful low temperatures, occurred but did not interrupt tissue regrowth. Warmer than average sea surface temperatures occurred during the warm months from 2008 to 2011, during which time a cool period occurred from 2010 to 2011. While the magnitude and duration of temperature anomalies during warming were not as great as those observed during the 1997-98 ENSO, low temperatures observed during the cool period were similar to those experienced throughout the 2007-08 La Niña. During this time total live tissue cover was reduced by 19% (n=10); however it is unknown whether this was due to warming or the following cool period. Based on results from the 1997-98 El Niño and 2007-08 La Niña, this reduction in live tissue was most likely caused by elevated sea surface temperatures. Data on the growth and resilience of P. lobata populations at Devil’s Crown will be used for conservation and management of this important resource.
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Gratwicke, Brian. "Factors affecting fish distribution in coastal habitats of the British Virgin Islands." Thesis, University of Oxford, 2004. http://ora.ox.ac.uk/objects/uuid:f0b83565-7ed9-4612-ac98-b203b19a8be5.
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Few studies of tropical fish communities compare fish distributions across the full range of near-shore tropical marine habitats. As a result, our understanding of tropical marine fish communities is often biased towards habitats preferred by researchers. The distribution and habitat preferences of all 136 fish species occurring at 106 stations in three bays off Tortola in the British Virgin Islands were assessed. At a species level, habitat type was often the key factor influencing fish distribution. Of the 44 species occurring at more than 10 stations, 3 were sand specialists, 5 were strongly associated with mangroves, 7 were dependent on seagrass and algal beds and 14 were found only on the forereef. Eleven species were widely distributed both on the forereef and in bays, and 9 of them showed clear evidence of ontogenetic partitioning. The juveniles all preferred bay habitat types and moved onto the forereef as they approached sexual maturity. At a community level, five distinct fish assemblages were found. The assemblage types were classified according to their distribution: 1) forereef, 2) reef flat, 3) non-mangrove associated seagrass, 4) mangrove associated seagrass and 5) eutrophic areas. Forereef stations were the most species-rich with 24 species per station while eutrophic stations had the most depauperate communities with only 4 species per station. Variation in fish species richness at each station was largely explained by a simple habitat complexity index. It accounted for 70% of the variation in fish species richness and 21% of the variation in fish abundance. Rugosity and variety of growth forms were the most important predictors of species richness, but the height of the habitat architecture was the most useful predictor of fish abundance. Artificial reefs were constructed to test the effects of each habitat complexity variable experimentally. Increasing rugosity, variety of growth forms and percentage hard substrate increased the observed number of species but increasing the variety of hole-sizes, and height had no effect. The only complexity variable that had a significant effect on fish abundance was percentage hard substrate. In addition to the static substrate structure, long-spined sea urchins Diadema antillarum affected fish distribution because small fish shelter from predators in their spines. The urchins increase species richness and abundance in low complexity seagrass beds, but on artificial reefs, where shelter was not a limiting factor, the effect was less pronounced. Organic pollution is another factor that negatively affects the fish community by reducing fish species richness and abundance. Poor water quality often alters the natural habitat, confounding observations, but fish species richness was reduced in polluted areas even when artificial reefs were used as habitat controls. The applications of these findings to the management and conservation of fish in the British Virgin Islands are discussed.
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Pickard, Alexandria E. "Characterization of Shark Movements on a Mesophotic Caribbean Coral Reef and Temporal Association with Fish Spawning Aggregations." NSUWorks, 2013. http://nsuworks.nova.edu/occ_stuetd/156.
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Habitat use of mesophotic coral reefs by sharks is largely unknown. However, it is well established that mesophotic reefs are the site of spawning aggregations for many species of teleost fish. These aggregations represent seasonal concentrations of potential prey biomass that may influence the habitat use of predatory species such as large sharks. I employed acoustic monitoring to examine the movements of three shark species lemon shark (Negaprion brevirostris), tiger shark (Galeocerdo cuvier), and Caribbean reef shark (Carcharhinus perezi)] to determine 1) the comparative spatiotemporal patterns of mesophotic reef habitat use by the three shark species and 2) the spatiotemporal relationship between these sharks and grouper spawning aggregations at a fish spawning aggregation (FSA) site (Hind Bank and Grammanik Bank) along the southern reef shelf edge off St. Thomas, United States Virgin Islands (USVI). Tiger and lemon sharks were detected across nearly the entire acoustic array, which spanned ~ 1060 km2. When present, Caribbean reef sharks used a much smaller activity space, composed exclusively of mesophotic reef habitat located within FSA sites. Individuals from all three species were typically detected for stretches of several consecutive days, while periods without detections usually lasted less than one week. Lemon sharks were present at the FSA site more often during the grouper spawning season (Dec-May) than the non-spawning season (Jun-Nov), but showed no preference toward specific areas within the FSA site, which varied by location and grouper species composition. In contrast, there was no relationship between the presence of tiger and Caribbean reef sharks at the FSA site and the grouper spawning season. My results suggest that despite different habitat use patterns and varying degrees of fidelity, this mesophotic reef serves as an important habitat to all three shark species.
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Lybolt, Matthew J. "Count or Pointcount: Is Percent Octocoral Cover an Adequate Proxy for Octocoral Abundance?" [Tampa, Fla. : Matthew J. Lybolt], 2003. http://purl.fcla.edu/fcla/etd/SFE0000081.
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Goodman, James Ansell. "Hyperspectral remote sensing of coral reefs : deriving bathymetry, aquatic optical properties and a benthic spectral unmixing classification using AVIRIS data in the Hawaiian Islands /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.
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Nylander-Asplin, Hannah F. "Population Dynamics and Genotypic Richness of the Threatened Acropora spp. and their Hybrid in the U.S. Virgin Islands." Thesis, NSUWorks, 2018. https://nsuworks.nova.edu/occ_stuetd/498.
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Since the 1980’s, there has been an unprecedented decline in the reef-building Caribbean corals, Acropora cervicornis and A. palmata, which has led to their listing as “threatened” under the U.S Endangered Species Act. Despite this protective status, these Acropora species continue to experience declines primarily attributed to disease, global climate change, and storm damage. Recent evidence suggests the hybrid of these threatened species (A. prolifera) is found at abundances similar to or higher than the parental species at many sites throughout the Caribbean. However, there is still much that is unknown as to how and why hybrids may be increasing in abundance at select sites.
In 2007, scientists from NOAA NMFS established 9 permanent transects at three sites in the USVI to quantify fish diversity and coral tissue condition in A. cervicornis thickets. Over the years, they observed that A. prolifera seemed to be increasing in abundance on transects that were once dominated by A. cervicornis. This dataset provided a unique opportunity to investigate whether a shift from a threatened parental species to its hybrid may have occurred. This study has two objectives, (1) to quantify the change in A. cervicornis and A. prolifera percent cover and colony health over a 9-year period, and (2) to compare the genotypic diversity among the three Caribbean acroporids on and near the transects to determine the primary method of propagation, i.e., sexual versus asexual. For this study, I used transect photographs taken in March, July and November 2009, April 2012, and August 2017 to compare intra- and interannual variation in acroporid cover and colony health.
Striking losses were observed in A. cervicornis cover between March 2009 and August 2017. At Thatch Cay, A. cervicornis declined from 25.7% to 8.9% between March 2009 and November 2009, but remained stable (10.2%) up to August 2017. Acropora cervicornis cover declined from 13.2% to 0% at Lovango Cay, and from 8.2% to 0% at No-Name Bay. At the one site (No-Name Bay) that A. prolifera was present during the original surveys of the transects, the percent cover remained relatively high and stable over the sample period. At No-Name Bay, A. prolifera percent cover (18.2%) was significantly higher than A. cervicornis (5.4%) by November 2009. It appears that A. prolifera expanded in the habitat left void by the decline in A. cervicornis. The general health of A. cervicornis based on the amount of healthy versus white and pale tissue appeared to decline at all sites between March 2009 and November 2009. To determine if the high percent cover on some transects was derived from asexual propagation or sexual recruitment, 139 tissue samples were collected in 2017 and genotyped using five microsatellite markers. No significant difference in genotypic richness (number of unique genotypes divided by the sample size) was observed among A. cervicornis (0.62), A. prolifera (0.64), and A. palmata (0.68). This suggests that the hybrid colonization is from multiple sexually derived individuals, not just asexual propagation from a rare hybridization event. High genotypic diversity, stable population abundance, and healthier colonies, suggest acroporid hybrids may become the primary habitat building coral of shallow reefs in the U.S. Virgin Islands. Due to considerable differences in morphologies between A. cervicornis and A. prolifera, it is unclear how a shift to the hybrid may affect the organisms that occupy acroporid structure and if the same ecological functions can be fulfilled.
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Smith-Coffin, Margaret A. "Planning an underwater park." Virtual Press, 1987. http://liblink.bsu.edu/uhtbin/catkey/508009.
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This creative project concerned the planning of an underwater park off the western coast of Negril, Jamaica. Negril is the westernmost point in Jamaica. Negril was traditionally a small fishing village before the development of tourism in the late 1960's. The rapid growth of tourism and haphazard development that followed has had detrimental effects on the marine environment and local community. Much of the local economy still depends on fishing for its subsistence. The underwater park is an attempt to preserve and protect the reefs and linked habitats in Negril.Protecting the reef will ultimately benefit the local fishing economy. The reef, with its warm, shallow waters is a breeding ground for fish. The fish rely on natural protection in the reef until they are large enough to move out into open waters. The park will prohibit collecting of any fish or plant species within the park area or any other activity with negative impacts to the reef ecology.The intent of the study was to locate and identify the underwater interpretive resources (coral communities), closely linked marine habitats and to recommend park boundaries and designate levels of use and protection. Further intent was to identify current and potential impacts, determine the proper status for the park, outline management objectives, regulations, and specify management plans for the park.The Negril Underwater Park will exist for the purpose of encouraging maximum compatible development of the coral reef system, as a visitor attraction and recreation area, while preserving the resources from degradation through a program of controlled use. The park is also intended to protect habitats linked to the coral reef especially the Great Negril Morass, Sea-grass, beach, and Mangrove areas.Department of Landscape Architecture
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Alhababy, Adel Mohammed Yahya. "An assessment of grounding, anchoring and fishing methods on coral reef structures and reef fish near Kamaran and Uqban Seghir Islands, west coast of Yemen, Red Sea." kostenfrei, 2006. http://e-diss.uni-kiel.de/diss_1742/d1742.pdf.
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Schrader, Julian [Verfasser], Holger [Akademischer Betreuer] Kreft, Holger [Gutachter] Kreft, and Erwin [Gutachter] Bergmeier. "Coral islands in West Papua: A model system for functional and taxonomic diversity and the resilience of isolated habitats / Julian Schrader ; Gutachter: Holger Kreft, Erwin Bergmeier ; Betreuer: Holger Kreft." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://d-nb.info/1189904748/34.
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Wildes, Fred Thomas. "A resource management strategy for the Belize barrier reef system." Thesis, Virginia Tech, 1992. http://hdl.handle.net/10919/41513.
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The need for a broader geographical and functional perspective in managing natural resources of the Belize barrier reef system was examined. The small country of Belize in Central America is struggling to increase its economic development and growth. It has an excellent natural resource base, the most dramatic component being the extensive barrier reef system just offshore.
The research identified key economic and environmental issues relative to Belize’s reef complex, and analyzed resource management policies and actions taken to date. Development and conservation needs suggest a multiple use strategy aimed at economic and environmental sustainability. Due to areal extent and ecological complexity, the present reactive, small-scale and piecemeal approach is not adequate to realize sustainable utilization of the area’s resources. This research shows the need for a broad spatial and interdisciplinary “coastal zone" perspective, leading to a comprehensive and integrated strategy upon which to base resource planning and management.
A strategy for the reef system must be accomplished within the broader context of a national resource management strategy, integrating concerns of economic development and environmental protection. As a component of this national policy, the proposed strategy for the barrier reef system is based on principles of multiple use of resources, coastal zone scope, and sustainability. The research supports a reef system-wide protected area, using a biosphere reserve framework and a customized model planning process to implement the strategy.Master of Science
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Fourgon, Didier. "Etude intégrée (écologique, éthologique et morphologique) d'une symbiose interophiuridéenne dans l'écosystème corallien à Madagascar." Doctoral thesis, Universite Libre de Bruxelles, 2006. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210777.
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Leslie, James W. II. "My Nature." Kent State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=kent1196782535.
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Plass-Johnson, Jeremiah Grahm. "The trophic ecology of parrotfish of Zanzibar application of stable isotope analysis." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1005477.
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Parrotfish are a critical component of the herbivore functional group on tropical coral reefs around the world because they mediate competition that occurs between algae and scleractinian corals. Also, because of their feeding technique, which consists of rasping at the substratum with their beak-like teeth, they play an important role in carbonate turnover and the clearing of reef surface area for the settlement of new sessile organisms. Because of these roles, parrotfishes are an important structuring component of coral reef communities. However, individual species can play different roles depending on their physiology, behaviour and ecology. Despite the possible ecological differences that may exist amongst species, specific roles of the fishes remain unclear as the group is most often studied at higher community levels. This thesis applied stable isotope analysis to differing levels of organisation within a parrotfish community to help elucidate their trophic ecology on coral reefs in Zanzibar. Firstly, blood and muscle tissues were compared to identify differences in their isotope signatures. In other organisms, blood turns over faster than muscle tissue so that muscle tissue represents the diet as integrated over a longer period of time. In most species of parrotfish the blood and muscle δ¹³C signatures were not found to be significantly different, but the δ¹⁵N signatures were significantly different between tissues. This indicated that the δ¹³C signature of both tissues would reveal similar dietary information. Conversely, differences in the δ¹⁵N signature indicated that the nitrogen relationship between tissues was more complicated. Secondly, spatial variability in parrotfish, coral, detritus and macroalgae isotope signatures was assessed at different scales. In macroalgae and coral tissues (zooxanthellae and polyp treated separately), the δ¹³C signatures were shown to differ with depth, presumably because of changes in photosynthetic processes related to depth-associated changes in light. While δ¹⁵N signatures were not affected by depth, all organisms showed enrichment at the Nyange reef, the closest reef to the capital of Zanzibar, Stone Town, presumably reflecting the effects of sewage outfall. These results show that processes that impact the δ¹⁵N signatures of primary producers (macroalgae and zooxanthellae) can be traced to higher trophic levels (coral polyps and fish). Lastly, δ¹³C and δ¹⁵N signatures were used to identify ontogenetic dietary changes in multiple species of parrotfish. Four of the species showed stages that varied from the diets that are normally assumed on the basis of their dentition and feeding technique. This indicates that functional roles based on taxonomy or morphology may fail to include possible ontogenetic dietary changes, and may also fail to elucidate the full impact a species could have on coral reef communities. The conclusions from these studies indicate that the species-specific ecological role of parrotfish in coral reef communities can be complex within and between species, and may differ amongst reefs. In light of the natural and anthropogenic pressures that affect coral reef systems, management decisions based on a more complete understanding of the role of these fish in coral reef communities will help decisions that maintain resilience in these fragile systems.
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Ortiz, Alejandra C. "Investigating the evolution and formation of coastlines and the response to sea-level rise." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/101835.
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Thesis: Ph. D., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Civil and Environmental Engineering; and the Woods Hole Oceanographic Institution), 2015.Cataloged from PDF version of thesis.
Includes bibliographical references.
To understand how waves and sea level shape sandy shoreline profiles, I use existing energetics-based equations of cross-shore sediment flux to describe shoreface evolution and equilibrium profiles, utilizing linear Airy wave theory instead of shallow-water wave assumptions. By calculating a depth-dependent characteristic diffusivity timescale, I develop a morphodynamic depth of shoreface closure for a given time envelope, with depth increasing as temporal scale increases. To assess which wave events are most important in shaping the shoreface in terms of occurrence and severity, I calculate the characteristic effective wave conditions for both cross-shore and alongshore shoreline evolution. Extreme events are formative in the cross-shore shoreface evolution, while alongshore shoreline evolution scales linearly with the mean wave climate. Bimodal distributions of weighted wave heights are indicative of a site impacted more frequently by tropical storms rather than extra-tropical storms. To understand how offshore wave climate and underlying geometry of a carbonate reef platform shapes evolution of atolls, I simulate the hydrodynamics of a simplified reef flat, using XBeach, a two-dimensional model of infragravity wave propagation. The reef flat self-organizes to a specific width and water depth depending on the offshore wave climate and characteristics of the available sediment. Formation of a sub-aerial landmass, like a motu, can be initiated by a change in offshore wave climate (like a storm), which can create a nucleation site from mobilization and deposition of coarse sediment on the reef flat. Once a motu is present, the shoreline should prograde until reaching a critical reef-flat width. Our conceptual model of reef-flat evolution and motu formation is governed by understanding the hydrodynamics of the system and subsequent response of sediment transport.
by Alejandra C. Ortiz.
Ph. D.
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Ossolinski, Justin Emerson. "Carbon budget analysis of the branching coral Madracis mirabilis." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 96 p, 2007. http://proquest.umi.com/pqdweb?did=1338884351&sid=14&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Stein, Jennifer. "Juvenile Scleractinian Coral Density, Composition, and Influence on the Adult Coral Population in Southeast Florida." NSUWorks, 2012. http://nsuworks.nova.edu/occ_stuetd/173.
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The purpose of this study was to collect baseline data of juvenile scleractinian coral density, spatial variability, size variability, and species composition across the linear shore parallel hard bottom coral communities offshore Broward County, Florida. Adult coral population data was also collected and compared with that of the juvenile coral population to better understand the local coral demographics and potential factors that influence the population structure. The juvenile and adult coral data from the Broward County coral communities was then compared to a second study region 50 kilometers south to identify latitudinal changes in the coral population structure.
The results of this study found that the densities and the list of coral species observed within the Broward County study region did fall within the range of densities found in other studies completed along the southern portion of the Florida Reef Tract and the Caribbean. Despite having similar species richness to other Caribbean studies, there was an overwhelming dominance of only a few species. This was also found in the adult coral population in the Broward study region.
The densities of both the juvenile and adult coral populations were significantly positively correlated as well as their number of species observed across the sites in the Broward County study region. Additionally, the highly dominant species found in the juvenile population were in the adult population.
Despite increasing coral density and diversity with decreasing latitude found in other studies conducted along the Florida Reef Tract, the results from this study were not as clear. Density of corals and the number of coral species did increase from north to south on the Outer reef however there was a significant decrease in the depth of the sample sites. On the Pavement habitat the density of juvenile corals increased from north to south however the number of coral species did not increase. The density and number of species of adult corals did not increase on the Pavement habitat with decreasing latitude as well making the results unclear.
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Collinson, Peter Ronald James. "The ecology of a peripheral, subtropical coral community in Hong Kong." Thesis, Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19667425.
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