The first bimonthly resolved, paired δ18O and Sr/Ca time series from the slow-growing, tropical western Atlantic coral, Siderastrea siderea, from the Dry Tortugas, Florida has been generated and used to document that robust proxy climate records can be produced from this heretofore underutilized massive coral. The coral time series contains a 20-year long calibration window (1973-1992) for both δ18O and Sr/Ca and a 73-year long verification window (1900-1972) for Sr/Ca. These time series permits both the quantification of the relationship between coral δ18O-SST and Sr/Ca-SST using an augmented, 1° x 1° gridded SST record and the assessment of the stability of the proxy relationships over time. Both coral geochemical records are highly correlated with the augmented instrumental SST record through the calibration period and Sr/Ca remains highly correlated through the verification period both at the bimonthly (r = -0.97) and annual average level (r = -0.72). Additionally, both coral δ18O and Sr/Ca are highly reproducible within the same core, and Sr/Ca exhibits no extension-related vital effects. Sr/Ca-SST anomalies are also significantly correlated to the augmented SST anomalies, despite the removal of the serial autocorrelation. The skill of this proxy demonstrates its potential as a continuously growing, long-lived recorder of climate variability for the tropical Atlantic and Intra-American Seas. The relatively slow extension rate of the coral (~5 mm yr-1 during the 20th century) also suggests the potential for long records of climate variability (~200 years) of the region to be extracted from even modest-sized colonies (~1 m in height). The results of this study are important because relatively few century-long, sub-annually resolved time series of climate variability from massive Atlantic corals have been published, despite the significance of the tropical Atlantic climate modes of variability.

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

The resilience of coral reefs depends, among others, upon local physical and biological characteristics. This dissertation focused on how herbivory, structural complexity, and sedimentation can impact the structure, function, and, ultimately, resilience of Caribbean coral reefs. We filled an important knowledge gap related to trophic niche and ecological roles of surgeonfishes (A. coeruleus and A. tractus), two of the most important herbivorous fishes in the Caribbean. We showed that both species feed primarily on turf algae preventing further progression of algal succession while A. tractus may also help reduce macroalgal abundance by targeting common macroalgal species such as Dictyota spp. We used a factorial experiment to analyze the interactive effects of herbivory (exclosure vs. open plots) and reef structural complexity (vertical vs. horizontal substrate orientation), on the development of benthic communities. We found that vertical substrates were quickly dominated by crustose algae regardless of herbivory treatment while succession of horizontal substrates was determined by herbivory. Our results suggest that at small scale, reef complexity is a major factor determining algal community structure. We investigated why, despite high levels of herbivory, coral cover in South Florida has failed to recover. We surveyed benthic composition, grazing and abiotic characteristics along six spur and groove reefs in the Florida Keys. Using boosted regression tree analyses, we found that sediment abundance was the best predictor of both juvenile and adult corals, which could explain the failure of coral recovery. We studied spatial and temporal changes of reef communities of reefs in Havana, Cuba where global and local stressors have affected coral communities while overfishing and nutrient enrichment has led to low herbivory levels. Our surveys revealed a region-wide high abundance of algae (~60%) as a consequence of heavy overfishing with likely negative consequences on coral recovery. In summary, my dissertation showed context-depend effects of herbivory, structural complexity, and sediment on Caribbean coral reefs. While reduction of herbivory can often suppress coral recovery, on coral reefs with robust herbivore populations, physical factors such as structural complexity and sediment may still limit coral recovery and fundamentally impact reef resilience.

There is much evidence supporting the idea that pelagic larvae of coral reef fishes are active participants in their dispersal and return to a reef, however, the mechanisms used to navigate are still uncertain. It has been proposed that sensory cues, such as hearing, play a role. Sound is a potentially important cue for organisms in marine environments, especially in noisy environments like coral reefs. Sensory organs, including otolithic organs, of most coral reef fish form within the first few days of life. The auditory brainstem response (ABR) technique was used to measure hearing on a wide size range of sergeant majors (Abudefduf saxatilis). Complete audiograms were measured for 32 fish ranging in size from 11-121 mm. Significant effects of standard length on hearing thresholds at 100 and 200 Hz were detected. At these lower frequencies, thresholds increased with an increase in size. All fish were most sensitive to the lower frequencies (100-400 Hz). The frequency range that fish could detect sounds was dependent upon the size of the fish; the larger fish (>50mm) were more likely to respond to higher frequencies (1000-1600 Hz). A. saxatilis have poor hearing sensitivity in comparison to audiograms of other hearing generalists including other species of Pomacentrids. Due to the high hearing thresholds found in this study in comparison to recorded ambient reef noise, it is unlikely that sound plays a significant role in the navigation of the pelagic larvae of sergeant majors to the return of the reef from large distances.

Historically, Archaias angulatus has been a major contributor to foraminiferal assemblages and sediments in coral-reef environments throughout the Caribbean and tropical Atlantic. A variety of anomalous features were observed in the tests of A. angulatus individuals collected live from the Florida reef tract in 2004 and 2005. Six types of anomalies were documented using scanning electron microscopy: microborings, microbial biofilm, pitted surfaces, dissolution, calcification abnormalities, and growth abnormalities. Calcification abnormalities included mineralogical projections, lacy crusts, and repair marks. These abnormalities were found among both juvenile and adult A. angulatus, and similar features were also found among Cyclorbiculina compressa and Laevipeneroplis proteus specimens collected live in the same samples. In 2006, a comprehensive study was undertaken to see if the occurrence and types of morphological abnormalities have changed in A. angulatus from the Florida Keys over the past 2.5 decades. Archived samples of A. angulatus collected in 1982-83 from John Pennekamp Coral Reef State Park were compared to recent samples. Seven different types of morphological abnormalities and 5 different surface texture anomalies were documented. Eighty-six combinations of abnormalities and surface textures were observed. Physical abnormalities included profoundly deformed, curled, asymmetrical, and uncoiled tests, irregular suture lines, surface "blips," and breakage and repair. Surface texture anomalies included surface pits, dissolution, microborings, microbial biofilm, and epibiont growth. Epibiont growth included bryzoans, cyanobacteria and foraminifers. The archived samples were not obviously more pristine than the recent samples indicating stress was well underway in the early 1980s. Test strength was compromised in deformed specimens. Crushing strength of abnormal individuals was much more variable compared to individuals with irregular sutures and normal specimens. Deformed individuals also exhibited abnormal test wall structure including dissolution and infilling. Mg/Ca ratios for normal and deformed specimens were within normal parameters (12-15 µmol/mol). Implications of these observations are at least twofold. First, in studies of fossil assemblages, damage to tests and changes in test-surface textures should not be assumed to have occurred postmortem, and may provide evidence of environmental stressors acting upon living populations. In addition, we speculate that test dissolution in larger miliolid foraminifers when alive can indicate declining carbonate saturation in seawater, which can result locally from salinity changes or increasing benthic respiration rates, as well as globally from rising concentration of atmospheric CO2.

A goal of the U.S. Environmental Protection Agency is to develop protocols applicable to coral reefs to distinguish between the effects of local water quality and those associated with regional to global environmental change. One test case is the current-dominated southeast coast of Florida where the Delray Outfall delivers 30 million gallons per day (114,000 cubic meters per day) of secondary-treated sewage into the ocean. Five study sites were established at depths between 15 and 18 m, and at distances between 1 and 18 km distance from the outfall, where the Stony Coral Rapid Bioassessment Protocol (RBP) was conducted to determine coral cover and selected other parameters. During sampling, 29 surface sediment samples were collected that I analyzed with respect to sediment texture, foraminiferal assemblages, and sediment constituents. Most samples were characterized by fine sands with <2% mud. A total of 77 genera of foraminifers were identified, averaging 28 genera per sample. Abundances of foraminiferal shells varied among samples by more than an order of magnitude (83 to 1010 shells per g sediment). The Foraminifera in Reef Assessment and Monitoring (FORAM) Index was calculated from the foraminiferal data, yielding values of 3 or more for all sites, with 26 of the 29 test sites yielding values >4, indicating that water quality should support coral growth. Sediment constituent analyses revealed that the sediments were overwhelmingly dominated by unidentifiable fragments (60%), with molluscan debris second (20%), and calcareous algae third (4.5%); larger foraminiferal shells and coral fragments together made up < 5.5%. The resulting sediment constituent (SEDCON) Index was consistently <2, indicating that erosional processes dominate over sediment production along the sampled shelf area. Results provided by the FORAM and SEDCON indices are consistent with results for stony coral based on the RBP. Stony coral cover was low at all sites, <2%, indicating that coral occurs in the area but neither dominates the benthos nor builds reefs. No relationship was observed between any parameter and distance from the Delray Outfall. However, both the RBP and FORAM Index indicated poorest conditions at the Horseshoe site, suggesting unidentified stressors in that vicinity.

This study focuses on how the construction of a paleoclimate time series influences the interpretation in the frequency domain. Three time series are examined: a New Caledonian coral (Amedee Island), a Chinese speleothem (Dongge Cave), and New Mexican trees (El Malpais). This study presents a monthly resolved coral Sr/Ca time series from New Caledonia that reconstructs sea surface temperature (SST; 1648-1999). The chronology is based on density-band counting, cross-correlating Sr/Ca, and ²³°Th dating. The intracolony coral Sr/Ca variations are coherent on interannual to centennial time scales and are reproducible for >300 years. The SST reconstruction reveals estimated cooling trend (~0.4°C) from 1741-1815, a colder nineteenth century (~0.6°C), and a warming trend (~0.6°C) in the twentieth century. Spectral and wavelet analysis reveals significant inter-decadal periodicities (~14-21 years/cycle) that modulate with time, and nearly persistent multi-decadal periodicities (~25-33 years/cycle) that do not exhibit coherence with the Inter-decadal Pacific Oscillation. The multi-decadal periodicities may be a harmonic of the inter-decadal periodicities or may represent an independent mode not previously recognized. The Dongge Cave time series is based on uneven time intervals between data points (∆t) requiring interpolation to a constant ∆t for analysis with traditional spectral methods. A comparison of the even and uneven ∆t spectra using the Lomb-Scargle transform reveals the interpolated spectrum contains suppressed periodicities (<20 years/cycle), in contrast to the uninterpolated spectrum, resulting in a steeper slope in the red noise model thus influencing significance testing. The El Malpais time series is an average of tree-ring width series. Spectral analysis of the entire time series identified significant periodicities. However, significance varies between three temporal subsets, in which the number of series varies; therefore, these periodicities may be a function of the number of series or may represent a real temporal variability. Cross-spectral analysis of the El Malpais and Dongge Cave time series reveals significant coherence; however, cross-wavelet analysis, which examines localized frequencies in the time domain, reveals a lack of correlation; therefore, coherence in the frequency domain does not indicate correlation in the time domain.

Benthic mobile invertebrates are important components of coral-reef diversity and community structure, though, in most cases, their ecological contributions are poorly known. Baseline information on their diversity, prevalence, assemblages, and ecological roles is needed to aid in the conservation of coral-reef habitats. The objectives of this study are to 1) describe diversity and assemblages of epibenthic, mobile invertebrates in shallow water coral-reef communities in Florida, 2) evaluate their ecological roles by reviewing published literature on diet, and 3) measure the degree of linear dependence between mobile invertebrates and scleractinian corals. Underwater surveys were conducted in the summer of 2013 at 40 sites distributed along the Florida Reef Tract from Broward County to the Dry Tortugas. The presence/absence of all mobile, epibenthic invertebrate fauna observed were recorded and identified to the lowest level possible. The survey data include 618 records of 116 unique taxa, 83 species, 61 genera, 46 families, 19 orders, seven classes, and four phyla of mobile invertebrates, comprising herbivores, detritivores, carnivores, omnivores, and suspension feeders. These taxa represent 22% of the comparable taxa in a historical dataset that spans 60 years, plus an additional 18 taxa. The survey data also show that the percent composition of major phyla is similar to the historical dataset, despite taxonomic bias evident in the historical dataset. During the survey, novel unique taxa were encountered frequently, but were seldom recurrent, which highlights their cryptic nature. While regional patterns were not identified in the study, assemblages of dominant taxa were characteristic of reef type: echinoderms were the most diverse on patch reefs and southeast Florida reef complexes, mollusks were most diverse on shallow bank reefs, and arthropods were diverse on deep bank reefs, Southeast Florida reef complexes, and shallow bank reefs. Herbivorous mobile invertebrate diversity was negatively correlated with scleractinian coral diversity, underlining competition between corals and macroalgae, and association of herbivores with macroalgae. All of these results suggest that reef types are distinct, but interrelated communities of fauna having specific habitat requirements and important roles. This study also reinforces the challenges in assessing the diverse and often cryptic mobile invertebrate fauna and emphasizes the need for further research and monitoring to detect changes in their communities for the conservation of Florida reef systems.

Attaining the ‘appropriate’ balance between human use of national parks and their protection is a topic of considerable public, scientific and business interest and is thus an important focus for research. An increasingly affluent and mobile western society has made tourism the world’s largest industry; an industry with a significant reliance on the attractions of protected areas such as national parks and their wildlife. Regional communities have benefited from protected areas through local tourism expenditure and government recognition of the economic and social values realized from protected areas. High levels of visitation, and the management of this human use require effective management. But tensions arise when park managers invoke policies and management prescriptions to mitigate the adverse affects of human use. These actions and the way they are implemented can have an alienating impact on local communities, particularly those with a direct business dependency on park tourism. This thesis explores the notion that truly sustainable management of national parks can only be achieved if park managers and communities living adjacent to parks work together in a partnership to meet each other’s needs and through this process, foster the long-term environmental, social and economic benefits that can be derived from these parks. This thesis documents how a local community perceives its park managers and thereby the impact that park management has on local communities. It then seeks to identify the opportunities for park managers and communities to improve the way they view each other and the skills, attitudes and approaches necessary to create the environment for a sustainable relationship and can deliver sustainable outcomes for both parties. / Three methods were employed to progress this research; an extensive review of literature and theory on relevant aspects of the people and parks relationship; the use of a case study of communities adjacent to parks on the Ningaloo Coast; and, qualitative and quantitative surveys to inform those case studies. A resident perception survey of the Exmouth and Coral Bay communities was conducted in August 2005. At the same time key stakeholder representatives were interviewed. Secondary quantitative data on the areas economy and demographics was also collected to triangulate aspects of the primary data. The Ningaloo coast community’s perception of park management has been adversely affected by a recent (2004) management planning process for Ningaloo Marine Park that culminated in significant constraints being placed on recreational fishing access. Both the planning process and the decision have been the focus of community anger. Currently the levels of trust and respect within the community for the park agency and its management performance are low. Despite evidence that the parks of the Ningaloo coast make important social and economic contributions to the local communities of this area, the local community holds negative perceptions of the social and economic impacts of park management, and are influenced strongly by the local community’s attitudes, perceptions and feelings towards the park agency. The park agency’s inability to consult, involve and communicate with the local community (to the satisfaction of the local community) contributes to these attitudes, feelings and perceptions. / Key findings include; the prevailing norms and belief systems within the park agency reinforce the classic managerial paradigm; park management fails to accommodate broader social and economic measures, which diminishes trust and undermines attempts to foster community involvement and stewardship; ineffectual leadership, poor communication and outmoded approaches to planning and community engagement, local apathy to involvement in park planning and a lack of community education in regard to the promotion of park values, programs and activities compound this situation. The Ningaloo coast has the potential to provide an exceptionally bright future for its local communities, based largely on the inherent natural and cultural values of Ningaloo Marine Park, Cape Range National Park and other associated reserves. Whether the potential to develop community stewardship of the parks of the Ningaloo coast is fully met depends largely on the willingness of park management to relinquish some of its power, establish a suitable governance model in order to work collaboratively with the community and communicate effectively with it in order to achieve sustainable futures for both the park and the community.

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