Coral reefs on Florida’s Reef Tract (FRT) are susceptible to many anthropogenic influences including controlled freshwater discharges and agricultural runoff as well as high natural environmental variability from seasonal rainfall, runoff and upwelling. To better understand coral population structure and responses to sublethal stressors, populations of the scleractinian coral Montastraea cavernosa in the northern FRT were examined using a combination of genomic and transcriptomic techniques. Microsatellite genetic markers identified high local retention among sites and a slight southward gene flow. An in-situ temporal gene expression analysis utilizing a tag-based sequencing transcriptomic approach was used to analyze baseline coral health at St. Lucie Reef (SLR), off Stuart, FL. Temporal variation had the greatest influence of differential gene expression among M. cavernosa at SLR. Results will be shared with local resource managers and coupled with a complementary ex-situ experimental trial. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

Thesis (M.A.)--Ohio University, June, 2007. / Title from PDF t.p. Includes bibliographical references.

Thesis (M.S.)--University of North Carolina at Wilmington, 2003. / Includes bibliographical references (leaves : 46-50).

Global warming from anthropogenic greenhouse gas emissions causes temperature increases in aquatic ecosystems. The rise in environmental temperatures places sensitive organisms under thermal stress. Reef-building corals are a critically important group of animals that provide many ecosystem services for coral reef ecology and the economy and are at a high risk of loss from thermal stress. Thermal stress causes corals to lose their colour, i.e. become bleached, resulting from the loss of symbiont zooxanthellae. This diminishes the energetic benefits that zooxanthellae provide to corals leading to a decline in coral health and high mortality rates. However, corals are also predators and can thus draw nutrients from zooplankton prey to supplement their nutritional requirements. This study investigated whether heterotrophic feeding can ameliorate the effects of thermal stress on coral physiology by providing an alternative energy source to zooxanthellar photosynthesis. Fragmented Pocillopora damicornis coral colonies were exposed to daily maximum temperatures of up to 31°C while being either starved or fed. During the experimental period coral nubbins were monitored for changes in polyp extension, oxygen consumption rate, feeding rate, colour, chlorophyll a content, zooxanthellae density, antioxidant potentials and DNA integrity during stress and after a short recovery period. It was found that, as expected, coral polyp extension, oxygen consumption rate, colour health, chlorophyll a content, zooxanthellae density and DNA integrity were all adversely affected by thermal stress. This indicted that all these measurements were viable biomarkers for assessing the negative effects of thermal stress on coral health. Coral colour, oxygen consumption rate, chlorophyll a content, lipid content, antioxidant potential and DNA integrity were all significantly improved by feeding. These results indicate that feeding does play a role in improving overall coral health and supports the physiological processes in coral tissue during and after thermal stress. The conclusions from this study also have great significance for coral reef ecology and management as predictions of reef resilience can be made from zooplankton ecology and boosting zooplankton availability to corals may be considered to mitigate the harmful effects of thermal stress and bleaching. / M.Sc. University of KwaZulu-Natal, Durban 2013.

In 2008 and 2010, exotic drift pumice was collected from a total of 40 beaches around the main island of New Caledonia, Southwest Pacific. This island is enclosed by a barrier reef lagoon whose 2008 designation as a UNESCO World Heritage Site brought attention to the ongoing environmental degradation caused by a century of open cast nickel mining. This type of mining is notorious for producing voluminous fine-grained waste sediment that clogs waterways and may compromise the biodiversity of the lagoon. This study examines the use of drift pumice as a visual marker of suspended sediment transported within and around the lagoon. The frequent, voluminous pumice eruptions in the region provide ample source material that is fairly durable and highly mobile in water. Geochemical analyses identified two recent eruptions in the central Tonga arc as the source of the pumice, which was transported to New Caledonia by the South Equatorial Current. Pumice abundance was shown to correspond directly with the incoming wave intensity. Coupling pumice distribution data with information about the beach morphology, it is possible to use land-based data collection methods to identify at-risk coastal areas exhibiting elevated fluvial input with reduced marine influence. / Methods -- Study area -- Regional setting -- Geomorphology -- Geochemistry -- Petrography -- Discussion. / Department of Geological Sciences

Koh Chang Marine National Park is a popular tourist destination located off the east coast of Thailand. Coral reefs are one of the park's main attractions, and thousands of visitors from around the globe enjoy the opportunity to snorkel or dive in the park's clear, warm waters. Rapid growth in Koh Chang's marine tourism industry over the last decade raises concerns about the ability of some reefs to sustain a healthy and attractive environment. Ecological and social impacts associated with increased levels of marine recreation can transform and even permanently destroy both the character of coral reef ecosystems and the quality of the recreation experience, ultimately resulting in declines in tourism demand. The broad objective of this study was to establish a baseline understanding of the social dimensions of the snorkeling industry in Koh Chang, Thailand, and to recommend a suite of management actions that will sustain economic benefits while still yielding the benefits of protecting aesthetic and biological values. The recreation carrying capacity, Recreation Opportunity Spectrum, and Limits of Acceptable Change concepts were used to guide and inform the research. Data were collected using three primary methods: participant observation, unstructured interviews, and structured questionnaires. Personal observations and unstructured interviews allowed for an assessment of the park's environmental, social, and managerial settings. The tour operator questionnaire was designed to measure the size and characteristics of the snorkeling industry, awareness of environmental impacts, and support for visitor management strategies. The questionnaire was completed by eight tour operators. The visitor survey was designed to gain an understanding of the demographics of snorkelers, satisfactions, knowledge and awareness, and crowding. The survey was completed by 716 snorkelers. Results of the visitor survey suggest that snorkelers have a similar demographic profile compared with reef visitors in other parts of the world. Features of the snorkeling trip that had the greatest potential to add to, or detract from visitor experiences were related to the quality of the natural environment, a finding that is consistent with other studies of snorkelers and divers in coral reef settings. The social conditions were rated among the least important influences on visitors' experiences, a somewhat surprising finding as the number of other people is an important indicator of quality of the visitor experience in terrestrial environments. Overall, visitors were generally satisfied with the physical, natural, and social conditions, but the degree of satisfaction varied among individual snorkeling trip features. The lowest levels of satisfaction were expressed for the social conditions and several features related to the quality and condition of the natural environment. Low levels of satisfaction were also expressed for a number of service features. Results from personal observations, unstructured interviews, and questionnaires suggest that the environmental impacts of use may be significant. On a daily basis, reefs were touched, abraded, kicked, and stepped on by snorkelers, and these inappropriate behaviours can cause considerable damage to benthic organisms and the aesthetic appeal of the reefs. Tour operators' perceptions of impact were close to those defined in the recreation ecology literature, but operators may not be aware of the impact of their own behaviour on the marine environment. Over half of visitors perceived the impact of snorkeling on the reef to be "large/very large", suggesting that visitors have some awareness of the environmental impacts of use. The social impacts of use were also significant, as over 90% of visitors reported feeling at least slightly crowded, and 20% felt extremely crowded. Study results also showed that snorkelers are not a homogenous group. Variability in visitor response was explained in part by the recreation specialization framework, and country of origin. Differences between visitors' level of commitment to snorkeling and the underwater world were apparent between specialists and generalists, and specialization helped explain variability in environmental preferences, sensitivity to environmental impact, knowledge and awareness, and sensitivity to crowding. Visitors with different cultural backgrounds also had significantly different participation characteristics, satisfaction levels, knowledge and awareness, and crowding perceptions. Snorkelers are not homogenous, but unfortunately, the recreation settings provided are. Results from personal observations and interviews suggest that tour operators provide a single, uniform type of snorkeling experience that can be characterized as undeveloped with low levels of regimentation and moderate to high levels of use. Given the variability in the visitor population, provision of a single recreation opportunity may leave many snorkelers less than fully satisfied. This study identified several imminent threats to the quality of the visitor experience, reef conservation, and the sustainable' of the snorkeling industry. Active visitor management planning and resource protection programmes are urgently needed to balance park uses with the capability of the reefs to sustain such use indefinitely. Recommendations that contribute to improved visitor management and reef conservation are provided.

Thesis (Ph.D.)--University of Hawaii at Manoa, 1994. / Includes bibliographical references (leaves 235-249). / Microfiche. / xx, 249 leaves, bound ill., maps 29 cm

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1989. / Includes bibliographical references. / Microfiche. / xxi, 338 leaves, bound ill. 29 cm

Analysis of the pattern of zonation of reef corals off the Kona coast of Hawaii revealed the existence of four clearly defined zones. This pattern was confirmed at three sites where corals were counted using a series of 45 meter long transects running parallel to shore from depths of 3 to 40 meters. Clustering analysis dendrographs, spatial changes in illumination and rates of water movement, as well as growth and survival of coral transplants also confirmed the zonation pattern. Each of the four zones is characterized by a dominant coral species, substratum type, depth, and range of physical conditions. Each zone also appears to be in a different stage of community succession due to the frequency of large scale environmental disturbances from winter storm waves. The shallowest zone begins at the base of the shoreline cliff, ranges in depth from 2.5 to 8 meters, and has a bottom cover consisting mainly of irregularly shaped basaltic boulders; Pocillopora meandrina dominates coral cover in this zone. This species appears to be the first to colonize new substrata and persists in large numbers only in the near-shore boulder zone where mechanical stress from wave action is great enough to restrict the growth forms of more competitive species. Due to this high wave stress, the P. meandrina bolder zone appears to be in an early successional stage with low coral cover and dominance and relatively hiqh species diversity. Moving into deeper water the Porites lobata reef building zone ranges in depth from 6 to 14 meters and is characterized by a gently sloping solid basalt and limestone bottom. Porites lobata dominates coral cover by growing in massive lobed and encrusting colonies. While succession seems to be in an advanced stage, monopolization of available space does not appear to be complete enough to exclude a variety of less competitive species, resulting in relatively high species diversities. The third zone occurs on the reef slope and ranges in depth from 14 to 30 meters. Solid substrata is scarce and succession may be a late stage due to domination of bottom cover by thickets of Porites compressa. Most of the other species that persist in this zone avoid competitive interactions by growing above the level of P. compressa. Storm wave stress is most devastating to corals in this zone, and breakage of living colonies seems to increase diversity by reducing P. compressa dominance. Transport of living coral fragments appears to extend zonal boundaries and create new colonies. Extensive "rubble channels" occur in this zone, and these channels may get progressively larger due to churning of rubble fragments with each successive storm. The Porites lobata rubble zone occurs below the deep border of the P. compressa thickets and extends to approximately 50 meters, the depth at which coraIs cease to appear. Substrata consists mostly of fine sand and a variety of small encrusting corals are found growing on scattered rubble fragments. Specialized species with narrow physiological tolerances limited to this zone also increase species diversity. While maximum size of corals may be reduced in this zone due to low light intensity, lack of solid substrata probably determines the lower depth limit of coral occurance. Sand and rubble that is carried downslope during storms cause this zone to be physically unstable and succession appears to be constantly interrupted at early stages. This is in contrast to other deep reef areas, such as off Maui and the Red Sea, where substrata is solid to the depth limit of coral growth. These communities appear to be highly stable and diverse, and in late or climax stages. The depauperate nature of Hawaiian coral fauna is probably due to fairly rigorous environmental conditions in combination with difficulties in larval transport from coral evolutionary centers in the western Pacific. However, reef areas off Kona are relatively rich for Hawaii due to complete protection from tradewind generated seas, partial protection from long period north swells, and the steep nearshore slopes that extend below wavebase. / Typescript. Bibliography: leaves 173-181.

The ecology of patch reef fishes was studied to quantify the main factors that affect the natural variability of the fish community and to determine the effects produced on the community by experimental removal of predators. Initially, a year-long baseline description was completed of the physical, biological and ecological characteristics of 8 pristine patch reefs at Midway lagoon. For over 3 subsequent years, piscivorous predators were spearfished at least monthly, often for days at a time, on 4 of the 8 reefs. Fish populations were visually censused throughout the experiment. In all seasons and years of the project, daily recruitment rate of postlarval fishes to natural patch reefs was compared to that measured on standardized, artificial reefs of various sizes and degrees of inter-reef isolation. Finally, all baseline measurements were replicated and complete collections were made of all fishes, to validate the visual census method. Visual censusing was found to be of adequate precision and accuracy for most resident, non-cryptic species (highest for small patch reefs). Fishes could be assigned to size classes underwater by visual estimate with high accuracy. Rotenone collections were highly effective in quantifying many species commonly missed or underestimated in visual censuses. Only a few species composed the bulk of all recruits, while most species were rare or not seen at all. Variation between species was related to life history strategies or behavioral requirements. High temporal variability was found at the following scales: 1) Annuallywhere variability increased with the magnitude of recruitment, and different species recruited heavily in different years, suggesting that species specific factors in the plankton are more important than general oceanographic conditions; 2) Seasonally- pulsing strongly in summer, and occasionally late fall, when favorable environmental conditions may maximize growth and survival; and 3) Daily- with 1 or 2 strong peaks (each only a few days long) over a period of several weeks of low, variable recruitment. Small-scale spatial variability between replicate attractors (standardized artificial reefs) and between attractor types (coral and wire) were both high for a few species recruiting abundantly, although most recruits are probably substrate generalists. Rigorous visual fish censuses can adequately document moderate- to long-term temporal variation in the abundances of recently recruited juveniles on patch reefs (i.e., based on similar temporal patterns assessed by daily attractors). Daily total recruitment rate increased, although at diminishing densities, with (attractor) reef size, and with degree of inter-reef isolation. Abundances of recently recruited fish censused on neighboring, natural patch reefs (much larger than attractors) increased with reef size. The effect of isolation on these natural reefs was confounded by the stronger effect of reef size. These results suggest that if optimum size and spacing of reefs is provided, either by proper design of artificial reefs or selection of marine reserves, managers may enhance fish recruitment and ultimately improve local fisheries: Of the 135 fishes censused on the patch reefs studied, only 6 species together accounted for 70% of the total number of all fish, mainly due to heavy seasonal recruitment pulses. Strong seasonal and annual variability in recruitment was responsible for most of the temporal variation in fish abundance. The structure of patch reef fish communities at Midway was characterized by high unpredictability (e.g., great seasonal and/or annual variability in recruitment by common species, recruitment limitation for most species, and a high turnover rate detected by frequent sampling). Some predictions of the theory of island biogeography were also met by these fish communities (e.g., species richness correlated strongly with patch reef area, volume and relief). and total fish abundance. Some populations also exhibited a degree of long-term stability. Species diversity [H'] was similar among different size reefs. The experimental fishing on piscivores produced a catch composed mainly of lizardfish, due largely to immigration following the removal of other, competitively superior, highly resident piscivores. Scorpionfish and moray eels were also dominant predators. The expected decreases in catch-per-unit-effort were not realized, except for a quantitatively insignificant family (hawkfish). Conversely, the catch of the highly migratory lizardfish actually increased as fishing progressed. Changes in the catch composition for other piscivores related mainly to major changes in reef size or to patterns of large, inter-year recruitment fluctuations. Census data confirmed the major trends indicted by catch results. Sharks and jacks were attracted to the experimental reefs by spearfishing; the study was unable to determine whether their piscivorous effect was different between reef treatments. Patch reef fish communities at Midway were relatively resilient to long-term, intense fishing pressure on piscivores. However, enhanced survival of a large, annual, summer recruitment pulse of a common cardinalfish, synchronized with a temporary but significant reduction of lizardfish (the most prevalent piscivore) by fishing, suggested that an effect of predation on reef fish populations is experimentally detectable and considerable. However, temporal and spatial variability in recruitment, and reef size differences and changes in size were the primary factors responsible for the observed temporal patterns in fish abundance. COlnmunity analysis involves numerous confounding effects and requires the most careful interpretation for valid conclusions. / xvi, 321 leaves, bound : ill. ; 29 cm.