Coral reefs are threatened due to anthropogenic stressors, especially due to warming. Corals typically live in a narrow range of environmental conditions; however, some individuals are able to thrive in extreme temperatures. Such colonies could provide insight into how the coral holobiont acclimates or adapts to extreme temperatures. This study used the model coral species Stylophora pistillata (Esper, 1797) in the Saudi Arabian Red Sea, which is abundant and occurs across a range of desired microhabitats to examine the role of the environment on population structure and physiology. Specifically, this project aimed to 1) review the literature on S. pistillata used in stress studies to better understand the threats it faces, and where knowledge gaps exist, 2) conduct a demographic assessment of S. pistillata populations across different reefs and microhabitats, and 3) evaluate the physiological state of S. pistillata colonies occurring in these microhabitats with differing temperature profiles. The literature review revealed disparities in stress studies on S. pistillata, with most originating from the Gulf of Aqaba and conducted on temperature tolerance. The population assessment showed a high spatial variability in size structure, but a tendency for offshore reefs to have larger colonies and higher colony density. It also showed that purple color morphs tended to be more frequently encountered in the exposed reef flat zones. Similarly, the physiological study showed high spatial variability in chlorophyll, protein and lipid content, and skeletal and symbiont density. However, there was a clear seasonal component, with a multivariate analysis revealing the coolest sampling period as distinct. The metabolic profiles of S. pistillata indicated that offshore colonies differ from midshelf and nearshore colonies. Finally, an opportunistic study reports a case of S. pistillata bleaching due to an unusual occurrence of cold stress coupled with a low tide, supporting the notion that continued monitoring of this population on the reef flat is important for documenting rare evets and understanding their impacts on coral ecology. Taken together, this thesis establishes baseline information on the ecology of an important Red Sea coral inhabiting an extreme environment, and will be important for understanding its response to future changes.

<p> About half the Caribbean hermatypic corals died out at the Oligocene-Miocene boundary, about 25 Ma. Roughly two thirds of those corals which died out in the Caribbean are still extant in the Indo-Pacific. The coral and coral associate faunas of three Upper Oligocene and three Middle Miocene fossil reefs in western Puerto Rico were compared. Corals on these sites suffered 59% generic extinction, and 54% species extinction. Nearly all coral genera which are tolerant of turbidity or turbidity and cold water survived. All corals found exclusively or principally on Oligocene shelf-edge reefs became regionally extinct. There are no shelf-edge reefs documented from the Miocene in the Caribbean.</p> <p> Coral associates, the endolithic organisms which live in coral skeletons, were almost completely unaffected by this extinction. Likewise, reef and off-reef gastropods, bivalves, and echinoids suffered only insignificant reductions in diversity. Only corals and large benthic foraminifera were strongly affected by the extinction. It is significant that zooxanthellate organisms were the primary victims of this extinction. There is no evidence to suggest effects at higher trophic levels.</p> <p> Paleontological evidence from corals, coral associates, and gastropods suggests enhanced upwelling in the Caribbean during the Miocene and Early Pliocene. This enhanced upwelling could account for the extinction by cooling Caribbean coastal surface waters and restricting reef development to on-shelf patch reefs, where corals would be subject to more intense sedimentation. Paleoceanographic models indicating West to East deep circulation through the Central American Seaway during the Miocene provide a mechanism for this enhanced upwelling.</p> <p> Life history characteristics may have influenced survivorship among the corals, but apparently had no effect on coral associates. Corals which brood their larvae survived in greater proportions than corals which broadcast. This pattern is opposite that observed in studies on molluscs and other invertebrates.</p> <p> This regional extinction was important in the division of a previously cosmopolitan reef fauna into the modern provincial faunas. Explaining this minor mass extinction may contribute to an understanding of the volatile record of reefs in the larger mass extinctions of the Phanerozoic.</p> / Thesis / Master of Science (MSc)

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Image analysis was used to measure basal areas of selected colonies of Montastraea annularis and Porites astreoides, following the colonies over a three-year period from 2002 to 2004. Existing digital images of permanently-marked quadrats in the Caye Caulker Marine Reserve, Belize, were selected based on image quality and availability of images of selected quadrats for all three years. Annual growth rates were calculated from the basal-area measurements. Mean growth rates (radial skeletal extension) for M. annularis and P. astreoides were 0.02 cm yr-1 and -0.20 cm yr-1, respectively. Basal area measurements demonstrated a large degree of variability. Increases were approximately balanced by declines giving the impression of stasis. By removing negative values and correcting by 25% to allow for comparison with vertical growth rates, mean values increased to ~0.5 cm yr-1 for M. annularis and ~0.8 cm yr-1 for P. astreoides. Basal area as a growth measure was compared to methods used in earlier studies. A new growth index based on basal area and perimeter was proposed and modeled. This growth index can be useful for reporting growth measured from basal areas and comparable other methods. The index also measures negative growth, or mortality, which conventional methods cannot do.

Thomas Schelling proposed a simple spatial model to illustrate how, even with relatively mild assumptions on each individual's nearest neighbor preferences, an integrated city would likely unravel to a segregated city, even if all individuals prefer integration. Many authors assumed that the segregation which Schelling observed in simulations on very small cities persists for larger, realistic size cities. We describe how different measures can be used to quantify the segregation and unlock its dependence on city size, disparate neighbor comfortability threshold, and population density. We develop highly efficient simulation algorithms and quantify aggregation in large cities based on thousands of trials. In particular, we show that for the values of disparate neighbor comfortability threshold used by Schelling, the striking global aggregation Schelling observed is strictly a small city phenomenon. Along the way we prove that in the Schelling model, in the process of evolution, the total perimeter of the interface between the different agents always decreases, which provides a useful analytical tool to study the evolution. At the isolated reef Kingman, it was recently discovered that apex predators constitute 85% of the total fish biomass. This is in sharp contrast to most reefs, where the prey biomass substantially dominates the total fish biomass. The recent study at the two pristine reefs, Kingman and Palmyra also indicates that the predator:prey fish biomass ratio is an increasing function of reef cover. Based on these field observations, we model the fish biomass structure at a pristine coral reef. We introduce a new refuge based mechanism for predator-prey interaction with an explicit dependence on refuge size. Our refuge based model does not assume mass action interaction between predators and prey and may provide a new mechanism in ecology to produce inverted biomass pyramids. Our model yields both the inverted biomass pyramid and the increasing dependence of the predator:prey biomass ratio on reef cover. We add various forms of fishing to our model, and show that sufficiently high fishing pressure with quite general types of fishing transforms the inverted biomass pyramid to be bottom heavy.

Thesis (M.A.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 80-94). / xvii, 94 leaves, bound ill. (some col.), maps (some col.) 29 cm

Thesis (M.S.)--University of North Carolina at Wilmington, 2004. / Includes bibliographical references (leaves : [35]-41).

This paper concerns the planning for sustainable development of a global common pool resource within an autocratic region. The study is focused on the coral reef of the Red Sea, shared between the basin countries; Djibouti, Egypt, Saudi Arabia, Sudan, Yemen, Somalia, Israel, Jordan and Eritrea, where most nations are autocracies and developing countries. The viewpoint of this research is the only multinational project within the region focused on the conservation and sustainability of the coral reefs in the Red Sea, the “Regional Action Plan for the Conservation of Coral Reefs in the Red Sea and Gulf of Aden (RAP CCRRSGA)”. The aim of the research in this paper is to study the planning of this project in relation to sustainable development, through an interpretation of Ostrom’s framework using seven out of eight design principles. This research is executed through a method of ideal-type analysis, in order to assess how ideal-types of these design principles correlate with the planning of this project through similarities between the project and the design principles. This research has resulted in and demonstrated the importance of clarified compliance and cooperation, to reach effective and successful planning of sustainable development pertaining to a shared common pool resource within an autocratic region.

The Florida Reef Tract in Southeast Florida is made up of hard-bottom formations. The shape and size of the tract is constantly changing. One major factor contributing to these changes is the movement of sand. This is influenced by location-based, human-induced, and natural factors. These shifting sands cover or uncover reef structure. Images of the Florida Reef Tract in Palm Beach County were analyzed by the Department of Geosciences at Florida Atlantic University, using a partially automated method of mapping. There are notable changes in reef structure throughout the years 2004-2006, in which many major storm events occurred in the region. A time series analysis was conducted throughout these years. Losses and gains of reef structure were quantified and compared throughout the county as a whole, in beach renourishment project areas, and inlet intervals. Trends suggest that the major storms of 2004-2006 may have had effects on the reef tract. / by Joseph G. Pitti. / Thesis (M.A.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.