Thesis (M. Sc.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 117-126).

Thesis (M.S.)--University of South Florida, 2003. / Title from electronic document title page. Document formatted into pages; contains 103 pages. Includes bibliographical references.

No description available.

This study investigates effects of eutrophication on settlement, abundance, mortality and community structure of soleractinian corals on fringing reefs on the west coast of Barbados, W.I. Juvenile abundance was lower, but juvenile size larger, on eutrophic than less eutrophic reefs. The lower abundance results at least in part from a higher juvenile mortality on eutrophic reefs. Algae were more abundant and grazers (Diadema antillarum and herbivorous fish) less abundant on eutrophic reefs. Juvenile community structure on all reefs, and adult community structure on eutrophic reefs, was dominated by type 1 corals (high recruitment, high natural mortality). Type 2 corals (low recruitment, low natural mortality) were common in adult communities on less eutrophic reefs. Settlement of coral recruits on artificial substrates was lower on more eutrophic reefs.

Coastal communities along the east African coastline rely on coral reefs and their associated resources for food security and income. However, increases in the frequency and severity of episodes of coral bleaching have resulted in mass coral moralities in many locations around the world including the western Indian Ocean (WIO). Reef corals obligately host dinoflagellate algal symbionts of the genus Symbiodinium. Coral bleaching is caused by the loss of these symbionts from the host, resulting from a variety of stresses, the major ones being increased seawater temperature and irradiance. The Symbiodinum genus is diverse and the distribution of symbionts is influenced by the host biology, external light environment and geographic location. Ten distinct clades of Symbiodinium have been identified. Although the Caribbean and Great Barrier Reef have been studied intensively with respect to Symbiodinium diversity in many locations in the WIO Symbiodinium diversity is unknown. The aim of this study was to determine diversity, distribution and prevalence of Symbiodinium types in corals along the east African coastline. The Symbiodinium ssrDNA region was analysed using restriction fragment length polymorphism (RFLP) in order to assess the cladal diversity of Symbiodinium. The results showed all samples analysed to belong to clade C. To gain more insight into Symbiodinium genetic diversity, the ITS region was employed to assess Symbiodinium diversity at the subcladal level. Twenty ITS types were identified. The most prevalent type was found to be subclade C1. No phylogeographic structuring was found amongst the symbiont types, however, specificity of symbiont types to coral hosts was demonstrated indicating potential susceptibility to perturbations such as increased seawater temperature. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2007.

No description available.

Over the next three decades, there are many predicted disturbances to Earth’s oceans, such as El Nino and hurricanes, which will lead to mass coral bleaching effects. Marine protected areas have been utilized worldwide to maintain coral population sizes and remediate external stressors, such as overfishing or mining. Using a series of modeling techniques, this thesis will propose an experiment that will determine the optimal distance and location for a future MPA in New Zealand. It will also be measuring whether one large reserve or a network of smaller MPAs are more effective in the regeneration of stony corals. These models will be based on Solemosmilia variabilis, the most common stony coral in the region. Based on past studies, it is hypothesized that there will be a significant positive increase with the metapopulation growth of corals in both protected areas. It is also predicted that there will be a higher rate of connectivity within a network of smaller marine protected areas if the MPAs are less than 2 km apart. If the distance is greater, one larger MPA will be more effective due to the lower rates of genetic drift.

In this study reef corals from two Caribbean and adjacent regions in different periods were investigated. Sclerochronological records of corals from well preserved Miocene to Pleistocene reefs were used to document potential changes in seasonal and interannual climate associated with CAS uplift and closure. In southern Florida the Plio/Pleistocene Caloosahatchee Formation is cropping out. During the deposition of this stacked shallow marine sediments at the Plio/Pleistocene Florida carbonate platform, a rich coral fauna existed. Corals from the Caloosahatchee Formation were investigated herein, regarding to reveal high resolution (bimonthly) climatic archives in their skeletons. The second region investigated herein is the Cibao Valley in the Dominican Republic, where sediments of the Neogene Yaque Group are outcropping. Corals from the Late Miocene Cercado Formation and the Mio/Pliocene Gurabo Formation (both upper part of the Yaque Group) are discussed here. Both formations are mixed carbonate-siliciclastic deposits of the prograding inner-shelf and contain a well preserved faunal record. Sclerochronological methods are used to identify seasonal and interannual climatic variability. Especially radiography, stable isotope analysis and laser ablation measurements (LA-ICP-MS) were used and discussed with a special focus on the pristine preservation of the analysed coralline material.

Statement of purpose: The scope of this dissertation was restricted to exemplary studies on the effects of spectrum, intensity and modulation (as described above) of the photic environment of the common reef coral Pocillopora damicornis and its symbiotic dinoflagellate algae. Various aspects of its biology were investigated. In some cases direct comparison was wade with othar species to emphasize similarities or differences. The central hypothesis of this dissertation can be stated as follows: Subtle changes in the spectrum, intensity and modulation of the natural photic environment can produce a profound effect on growth, reproduction, primary production and general metabolism of the reef corals. / Typescript. Thesis (Ph.D.)--University of Hawaii, 1985. Bibliography: leaves 201-221.

Goals of this investigation were: 1) Differentiate between the effects of turbidity and sedimentation on corals. 2) Differentiate the effects of carbonate and terrigenous sediments on coral growth and metabolism. 3) Develop a predictive model relating increased sediment loading to the photosynthetic rate, growth and survival of corals. 4) Evaluate the validity of the widely cited "10 mg cut-off point" and determine the levels of turbidity and sedimentation that are tolerated by corals. Earlier studies suggest that coral reefs decline when sediment loading levels exceed a sediment trapping rate of 10 mg cm-2 d-1 or a turbidity of 10 mg I-1. An integrated experimental design linked field and laboratory experiments. In the field, corals were transplanted to sites with varying levels of sedimentation. Turbidity, as linked to reduced light availability, had a significant affect on coral growth and metabolism in laboratory experiments but not coral growth or survival in field experiments. Turbidity in the field was highly variable and influenced greatly by wind velocity and rainfall. Terrigenous (or land-derived) sediments influenced light extinction more than carbonate (reef-derived) sediments. In laboratory experiments turbidity was more important than sediment trapping rate in affecting the photosynthetic ability and growth rates of corals. The predictive model stated that the lower the light level (as caused by increased turbidity) the lower the photosynthetic production of corals. The model was supported by results of laboratory experiments where conditions were precisely controlled and monitored. Under field conditions, the predictive model did not hold due to extreme natural variability in sediment loading and variation in a wide range of other environmental factors encountered at the experimental sites. Corals tolerated turbidity exceeding 120 mg I-1 and sediment trapping rates in excess of 11 mg cm2 d-1. Sediment loading is correlated with other environmental factors such as nutrient loading and reduced salinity. Composition of sediment varies widely between different locations. The "10 mg cutoff may prove to be useful in setting limits to vigorous coral reef development, although individual corals or coral assemblages may be able to survive and grow at levels exceeding this value. / Thesis (Ph. D.)--University of Hawaii at Manoa, 2001. Includes bibliographical references (leaves 235-264).