Browsing Electronic Theses by Issue Date "01/01/2012"
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- ItemAnguillicoloides crassus, an invasive parasite of the American eel, Anguilla rostrata: Population dynamics in South Carolina estuaries and health impacts on the host(2013-03-08) Hein, Jennifer Lucille; de Buron, Isaure; Environmental StudiesA survey of American eels, Anguilla rostrata, was performed from five localities in South Carolina (SC) to evaluate the status of infection by the invasive parasite nematode Anguillicoloides crassus, and compare it with historical data from SC and other areas in North America as well as to determine how infection affects the health of the eels. The biomass of adult worms did not vary significantly with eel body length, salinity, season or locality, although prevalence and intensity of infection by adults did vary by locality. Larval intensity was significantly greater in the winter and also differed among localities. The lack of seasonal effects on the adult worm stage contrasts with studies from higher latitudes (north of 35 degrees latitude along the coast of North America). Significant variation in parasites among localities reflects possible differences in abundance of intermediate and/or paratenic hosts. A large portion of eels (25%) exhibited severe swimbladder damage, indicative of previous A. crassus infections. Swimbladder damage was lowest in the summer, possibly indicating mortality caused by the extreme water conditions that occur during SC summers including high temperatures and low dissolved oxygen values. A reduction in spleen, liver, and eviscerated mass associated with infection by adult A. crassus indicated that infection may cause anemia and reduction in energy stores and these effects appear to be more severe in smaller eels due to a higher parasite biomass to body mass ratio.
- ItemAnthropogenic Impacts on Herpetofaunal Diversity and Community Composition on a Barrier Island in the Southeastern United States(2013-03-08) Hanson, Keith Miller; McElroy, Eric J; Environmental StudiesHabitat loss and degradation often negatively impact reptiles and amphibians. Understanding how human-induced habitat changes impact herpetofauna is crucial for effective conservation and management of their populations. My goal was to determine the impacts of human development on the herpetofauna of Kiawah Island, a barrier island in South Carolina, USA. I used drift fence arrays with pit and snake traps, cover boards and visual encounter surveys to sample herpetofauna at twelve sites in three areas along a gradient of developmental density (low, moderate and high). Species richness was highest in the low development area with 16 species, while the moderate and high areas contained 14 and 13 species, respectively. Abundance was also highest in the low development area with 587 individuals encountered. Amphibian diversity was highest in the low development area, while reptile diversity was highest in the moderate and high development areas. Species richness and abundance were significantly higher in forest habitats than in sand dunes. Fragment size had no impact on species richness, abundance or evenness, whereas canopy cover, plant species richness, and site elevation best explained variation in herpetofaunal species richness and abundance on the island. Community composition was fundamentally different between development areas, with the largest number of families, and largest range of sensitive species found in the low development area. Certain sensitive species were entirely absent from the high development area of the island, and were only found in the least developed, most inaccessible sites. Furthermore, the low development area had four unique species, whereas the moderate area hand one and high area had none. These results suggest that development on Kiawah has impacted species diversity and composition, as areas of high development area associated with low species counts and reduced numbers of sensitive species. Continued development and habitat modification on Kiawah will likely result in a herpetofaunal community dominated by a few, disturbance-tolerant species. These results indicate that a mixture of various levels of development, some of which must be low, may have the ability to maintain herpetofaunal species diversity and composition on Kiawah.
- ItemASSESSMENT OF THE SPATIAL STRUCTURE, GENETIC DIVERSITY, AND TEMPORAL EFFECTIVE POPULATION SIZE OF RED PORGY (Pagrus pagrus) IN THE SOUTH ATLANTIC BIGHT, 1978 - 2010(2013-03-08) Murray, David; Reichert, Marcel; Marine BiologyRed porgy, Pagrus pagrus, is a protogynous hermaphroditic reef fish that associates with hard-bottom habitats in temperate waters. Red porgy has been a recreational and commercially important species over the past 30 years, and is managed as a single species in the Snapper-Grouper complex under the South Atlantic Fisheries Management Council (SAFMC). During the early 1980's, increased fishing pressure began to significantly reduce the population in the South Atlantic Bight (Cape Hatteras, NC to Cape Canaveral, FL) resulting in a moratorium being enacted in 1999. The aim of my study was to determine how fishing pressure over the past 40 years has affected the genetic diversity of the South Atlantic Bight population of red porgy using nine microsatellite loci. An initial spatial evaluation of genetic diversity within the South Atlantic Bight was used to verify the previously identified lack of genetic structure using more robust sampling and marker designs. Genetic data coupled with life history data were used for a temporal comparison of allelic diversity, heterozygosity, and effective population size. Temporal analysis indicated that the genetic diversity of the stock has not been compromised with reductions in population size. Additionally, effective population size was estimated to be several orders of magnitude lower than census size (Ne = 179 - 1592), but remained relatively unchanged through time. The red porgy population has been experiencing heavy fishing pressure over the past 40 years, but appears to have maintained its genetic stability. However, the South Atlantic Bight red porgy is not in an optimal state and future efforts should continue to rebuild the population.
- ItemAssociations between parasite burden and health in the spotted seatrout Cynoscion nebulosus(2013-03-08) Cosmann, Paul Jerome; de Buron, Isaure; Marine BiologySpotted seatrout Cynoscion nebulosus are commonly infected by three species of parasites in South Carolina estuaries: the myxosporeans Kudoa inornata (in skeletal muscle) and Henneguya cynoscioni (in the bulbus arteriosus), and the digenean Cardicola laruei (in the ventricle). Because of potentially high pathogenicity by these parasites, we hypothesized that they negatively affect the fishes' health. Burden of infection by each parasite species was quantified in wild-caught spotted seatrout over the course of one year using histology. Fish health was assessed in terms of body and liver masses (measures of energy storage), and spleen mass (a measure of immune response and/or erythropoiesis). Using general linear models to control for the effects of body length, sex, and season, we found that C. laruei was associated with reduced body mass and that K. inornata was associated with reduced liver mass. All three species were associated with changes in spleen mass, with C. laruei being associated with enlarged spleens in all seasons, whereas the effects of K. inornata and H. cynoscioni on spleen mass were season-dependent, with a negative association for K. inornata in the spring and a positive association for H. cynoscioni in the spring. Overall, C. laruei was found to be the parasite that may impact the most the overall health status of the spotted seatrout and H. cynoscioni the least.
- ItemA Characterization of Bottlenose Dolphin (Tursiops truncatus) Interactions with the Commercial Shrimp Trawl Fishery of South Carolina(2013-03-08) Greenman, Justin Theodore; McFee, Wayne; Environmental StudiesIn the United States, interactions between the shrimp trawl fishery and bottlenose dolphins (Tursiops truncatus) are known to exist, however the level of mortality is largely unknown. The current study attempted to determine if interactions between bottlenose dolphins and commercial shrimp trawlers pose a significant threat to dolphin populations and if fishery related mortality is underreported. This was accomplished with a combination of on-board observations, a shrimp fisher mail survey, and stranding record research. On-board observations were made during a 112 day field study consisting of fishery-dependent (Aug. - Dec. 2010) and fishery-independent (Apr. - Nov. 2010 & 2011) sampling. These observations focused on direct physical interactions with the gear and depredation behaviors. Additionally, a sub-sample of shrimp fishers in South Carolina was asked to participate in a mailed survey. The survey included questions related to gear, dolphin observations, and the status of the shrimp fishery. This study also utilized historical dolphin stranding data from the South Carolina Marine Mammal Stranding Network to ascertain signs of shrimp fishery interactions. A three-leveled flow diagram was developed to characterize each stranding case according to the likelihood that mortality resulted from trawler interaction. Field results point to significant dolphin presence around commercial trawlers (chi sq. = 23.406, p <0.001). In addition, survey results showed substantial evidence that fishery related mortality is higher than reported. Finally, stranding records revealed several more cases with signs of possible trawler interaction. Therefore, the current designation of the fishery as a Category II fishery is correct. In addition, increased observer coverage and improved communication with the fishery on the importance of reporting takes is warranted.
- ItemCharacterization of the Symbiodinium microadriaticum Spliced Leader RNA and its Response to Stress(2013-03-08) Feltman, Peter; Van Dolah, Frances; Marine BiologySpliced leader (SL) mediated RNA trans-splicing has been identified in diverse dinoflagellate species, including the coral symbiont, Symbiodinium microadriaticum. During the process of SL trans-splicing, first described in trypanosomes, RNA messages are trans-spliced with an identical, short leader sequence, donated from a small nuclear-encoded RNA known as the SL RNA. Under conditions of severe stress, trypanosome cells shut off transcription of the SL RNA gene, a response termed spliced leader silencing (SLS), resulting in a cellular decrease in mRNA maturation and translation. This study sought to characterize the Symbiodinium SL RNA and determine its response to cellular stress. Our results revealed a non-polyadenylated RNA with numerous characteristics in common with other published dinoflagellate SL RNAs including sequence identity, small size, and a divergent secondary structure. Utilizing this sequence information, a qPCR-based assay was developed to measure the abundance of SL RNA in response to cellular perturbation. This assay was found to be responsive to transcription inhibition by treatment with actinomycin D. Cultures were assayed for SLS following incubation at 34° C, a temperature that causes extreme physiological impairment, and treatment with 4 mM DTT, a known cause of SLS in trypanosomes. SL RNA levels were unaffected by either treatment, suggesting that SLS is not a Symbiodinium stress response. To determine if the trans-splicing machinery was affected by either treatment, independent of SLS; unspliced, immature messages were assayed for by northern blot. No evidence was found for a reduction in trans-splicing in response to either heat shock or DTT treatment. These results, combined with the uncertain origins of the SL trans-splicing mechanism, support the emerging view that functions of SL trans-splicing may differ among the diverse eukaryotic lineages in which it exists.
- ItemCommitment, Care, and Control: The Treatment of the Black Insane at the South Carolina State Hospital From 1900-1963(2013-03-08) Fowler, Catherine Alison; Ingram, Tammy; HistoryThe treatment of the black patients at the South Carolina State Hospital from 1900-1963 reflected the local, regional, and national political and social ideas about race and demonstrated the lengths that whites would go to in order to control the black population. Topics include the 1909 and two 1914 investigations into the conditions and treatment of patients at the hospital, occupational therapy, common physical and mental illnesses, and sterilization.
- ItemDetermining factors that influence the molecular quantification of the harmful raphidophyte Heterosigma akashiwo using a sandwich hybridization assay(2013-03-08) Doll, Cameron; Greenfield, Dianne I.; Marine BiologyMolecular approaches for detecting and quantifying harmful algal bloom (HAB) species have become more commonplace because of their capability to distinguish taxa and species. Sandwich hybridization assay (SHA) is a molecular probe technique that uses two DNA probes to detect species or taxon-specific large subunit rRNA sequences and can be used to quantify cell abundances in environmental samples without nucleic acid purification or amplification. However, the influence of certain physiological and methodological factors on SHA optical density (OD) remains unclear. Elucidating such factors will help in evaluating SHA's reliability as a HAB management tool. The following specific factors were addressed; (1) do HAB strains from geographically distinct populations react differently on the SHA, (2) are samples preserved in Lugol's iodine solution stable enough for SHA quantification, (3) does algal growth phase or diel cycle influence SHA OD, and (4) how do nutrient or light limitation affect SHA OD? All experiments were carried out in the laboratory using the globally-distributed, ichthyotoxic raphidophyte Heterosigma akashiwo as the study species because SHA has been developed and rigorously validated for it. Results showed that SHA standard curves for some of the strains did not vary significantly from previously published results, but a few strains did display distinct reactions. Samples preserved in Lugol's were quantifiable for a week at room temperature and up to four months when refrigerated. SHA OD declined as a culture progressed from exponential to stationary and decline phases, and displayed a diel trend. Nitrogen limitation had a significant influence on SHA OD whereas low phosphorus and light did not.
- ItemDeveloping Participatory GIS Methods for Lowcountry Environmental Planning(2013-03-08) Baker, Liah; Watson, Annette; Environmental StudiesThe South Carolina Lowcountry has experienced significant population growth and urban and suburban development in the past few decades, which is caused mainly by in–migration. This thesis analyzes the community and fishing economy of the town of McClellanville, SC and examines how these changes have affected the residents’ way of life in a rural area. Data were gathered through interviews, focus groups, and Participatory GIS exercises and analyzed using an open coding method of data analysis. The categorized results were then examined through the framework of social–ecological resilience theory to discuss the characteristics of the community and economy that participants wish to preserve, identify threats and vulnerability to their current system, and suggest methods to reduce those threats. Participant responses showed that McClellanville residents feel threatened by encroaching development and have already seen negative impacts of in–migration in their community. Participants expressed a strong desire to preserve the fishing village ambiance and close–knit community in their town as well as preserving the abundant natural resources they utilize for commercial, recreational, and subsistence activities.
- ItemEcological and Societal Benefits Derived from Coastal Restoration in Southern Louisiana(2013-03-08) Atkinson, Donald Lowell; Lovelace, Susan P; Environmental StudiesThis project examines specific coastal restoration projects in southern Louisiana to develop a method for determining which kinds of projects will most likely enhance the socioeconomic conditions of the surrounding region through physical improvement of the habitat. By applying an extensive review of the literature, examination of project compliance documents, and analysis of secondary data characterizing the well-being of parishes near selected restoration projects, I explored, conceptualized, and confirmed the relationship between specific, local ecosystem services (e.g. provisioning, regulating, supporting, cultural services) and various elements of human well-being (e.g. health, safety, economic security) impacted by four restoration projects and their respective restoration techniques: dredged material placement, sediment diversion, and artificial oyster reefs. Finally, I developed a qualitative evaluation matrix by which these projects and techniques were analyzed for their potential benefit to regional ecosystem services, and - through associations previously established on the national and regional scale - I made connections between these enhanced ecological services and the impact on community well-being.
- ItemEffects of Light and Iron on Growth and Physiology of a Polar Diatom, Fragilariopsis cylindrus(2013-03-08) Bennett, Jennifer Melville; DiTullio, Giacomo R; Marine BiologyThe Ross Sea, one of the most productive Southern Ocean regions, accounts for a substantial proportion of global primary production and is responsible for up to one fourth of the C02 export in this ocean. Both primary and export production in this region are thought to be mediated by the interaction of light and iron (Fe) bio-availability. Future climate change may produce significant changes in the mixing-irradiance regime, and in the supply of macro- and micro-nutrients, in the highly productive waters of the Antarctic continental shelf. In this context, there is a pressing need to understand the responses of the major groups of Antarctic phytoplankton to such environmental changes. The diatom Fragilariopsis cylindrus is a prolific species on the Antarctic shelf, inhabiting both sea-ice (low irradiance) and open-water (high irradiance) regimes. Laboratory culture experiments were performed to examine the growth and physiology of this diatom under nutrient-replete conditions at irradiances of 5-500 μE m-2s-1, on both acute and long term timescales. These allowed the sub-optimal, optimal, and supra-optimal irradiance for growth (5, 100, and 500 μE m-2s-1, respectively) to be assessed for this species, under which growth at varying Fe concentrations (0 - 1000nM Fe-EDTA) could then be examined. Cell number, biovolume, photosynthetic efficiency (Fv/Fm) and effective absorption cross section of PSII (σPSII), photosynthetic and photoprotective pigments, reactive oxygen species (ROS), and intracellular particulate dimethylsulfoniopropionate (DMSPP) were measured in these experiments. The results indicated that F. cylindrus maintained relatively high growth rates (μ= 0.1-0.4) over a wide range of irradiance levels under nutrient replete conditions, probably using various physiological mechanisms including xanthophyll cycling and decreasing effective absorption cross section at higher irradiance. These mechanisms were also employed under light and iron stress, accompanied by an approximate 25% decrease in growth rate (µ) values. DMSPP levels (up to 60 mM) may also be serving as an antioxidant free-radical scavenging pool under both iron and light stress, thereby preventing oxidative damage, within the photosynthetic apparatus.
- ItemEffects of management on the recreational Snapper-Grouper fishery of the southeast United States(2013-03-08) Hawk, Marin; Carmichael, John; Environmental StudiesThe goal of federal fisheries management is to "achieve and maintain, on a continuing basis, the optimum yield from each fishery" so fisheries can provide public benefit to current stakeholders and future generations (Magnuson-Stevens Act 1976, 16USC section 1801(b)(4)). To achieve these goals, fisheries managers have a variety of tools at their disposal, including bag limits and size limits. While many studies have investigated the success of these management tools in freshwater systems, few have investigated their effectiveness in marine systems. My thesis aimed to determine if bag and size limits set for black sea bass, vermilion snapper, and red porgy altered total catch, total effort, harvest-per-unit-effort (HPUE), discards or mean length of harvested fish in the marine recreational fishery in the southeastern United States. Using recreational fishery-dependent (MRFSS/MRIP and headboat) data, I investigated management regulation changes that affected the response metrics using several statistical analyses. The results indicate that size limits contributed to an increase in discards, and a subsequent decrease in harvest, as well as an increase in mean length of harvested fish. The management impact on HPUE and effort were less obvious, and it is likely that other external factors influence those metrics, often overshadowing the effects of management.
- ItemTHE EFFECTS OF SEDIMENT GRAIN SIZE AND SHELL CONTENT ON THE BURIAL TIME OF THE COQUINA, Donax sp.(2013-03-08) Bricker, Tessa; Bergquist, Derk C.; Marine BiologyAnthropogenic modifications of the coastal environment can significantly impact the physical characteristics and the biological communities of sandy beaches. This study examined how changes in the amount and the size of the shell in sediments affect the burrowing ability of Donax, an abundant and ecologically important genus of beach bivalves. Two laboratory-based experiments examining the burial behaviors of Donax sp. were performed: (1) a full factorial experiment utilizing four different grain sizes of sand (very coarse, coarse, medium, and fine) and four different percentages of crushed oyster shell (0, 25, 50, and 100%) and (2) a beach sediment experiment using sediment from two South Carolina beaches of differing grain size distributions along with shell mimicking those distributions and the shell grain size distribution found on the beach. In Experiment 1, increasing shell content increased time to complete burial, and the effect of percent shell varied by grain size. Shell had a significant effect on the burial time; the shortest burial times were in 0% shell and the longest were in 100% shell. Shell in fine and medium sand increased the burial time more than in coarse or very coarse sands especially at higher percentages of shell. Increasing the grain size distribution did not significantly increase the burial time. Coarseness due to shell increases the burial time more than coarse sand. This study may provide a mechanism behind some of the changes observed in the biological community as a result of changes in the physical characteristics of the beach sediment, particularly those following human impacts.
- ItemEmerging contaminants in the marine environment: An in vitro study of the immunotoxicological effects of DE-71, a commercial polybrominated diphenylether mixture, and perfluorooctane sulfonate on dolphin and murine immune cells(2013-03-08) Wirth, Jena; Fair, Patricia A; Marine BiologyThe effects of emerging contaminants on the immune system of mammals are poorly understood, with limited information available about the immunotoxicological effects of perfluorooctane sulfonate (PFOS) and DE-71, a polybrominated diphenyl ether (PBDE) mixture, at environmentally relevant exposures. Due to challenges of working with dolphins, this study assessed the effects of in vitro exposures of PFOS and DE-71 on immune functions in dolphins and mice to determine the predictability of in vitro effects to in vivo observations as part of a parallelogram approach to assessing risk. Bottlenose dolphin peripheral blood leukocytes and B6C3F1 mouse splenocytes were exposed in culture to PFOS at 0, 0.01, 0.05, 0.1, 0.5, 1.0 or 5.0 μg/mL concentrations or DE-71 at 0, 0.025, 0.05, 0.25, 0.5, 2.5, 5.0, 25 or 50 μg/mL concentrations. The immune endpoints assessed were natural killer (NK) cell activity and lymphocyte proliferation. PFOS significantly decreased NK cell activity at 0.01, 0.05, 0.1, 0.5, and 1.0 μg/mL concentrations in mouse splenocytes, but did not significantly alter dolphin NK cell activity. Mitogen-induced T cell proliferation was significantly decreased in murine cells beginning at the 0.05 μg/mL treatment, but not in dolphin cells. B cell proliferation was not statistically altered by PFOS exposure in either dolphins or mice. DE-71 in vitro exposure did not significantly alter NK cell activity or lymphocyte proliferation in dolphins. It also did not alter lymphocyte proliferation in mice, but did augment NK cell activity beginning with the 0.05 μg/mL treatment. Using these in vitro models and previous studies on in vivo models, the parallelogram approach was able to estimate potential effects of PBDE and PFOS in free-ranging bottlenose dolphin immune function.
- ItemEnglish Demonism and the Threat of Supernatural Belief in Reginald Scot's The Discoverie of Witchcraft (1584)(2013-03-08) Shanshala, Michael Edward; Coy, Jason; HistoryThis study argues that the Protestant discourse on demonic temptation in sixteenth-century England played a role in shaping Reginald Scot's skepticism of magic, witchcraft, and corporeal demons. I develop witchcraft historian Phillip C. Almond's characterization of Scot as a "spiritual demonologist" concerned with identifying those who had fallen under diabolic manipulation. This study maintains that Scot's disbelief in the supernatural, as well as his demonization of folk magicians, witchcraft theorists, and demonologists, stemmed from this spiritualization of Satan. Scot's insistence that Satan lacked physical agency was a rigorous magnification of an existing trend in demonic representation that portrayed subversion as the Devil's principal tool against the faithful. Scot's amplification of English demonism predisposed him to see falsehood and blasphemy in places where his peers saw proof of magic, witchcraft, and demonic attack. The results of this study suggest that the internalized view of Satan in post-Reformation England helped foster the development of English witchcraft skepticism.
- ItemFrom Romanticism to Empire: Changing British Perceptions of Indian Architecture Throughout the Long Nineteenth Century(2013-03-08) Wood, Jennifer Lynne Bean; Grenier, Katherine; HistoryFollowing the Sepoy Rebellion (1857), India's architecture came to play a key role in Britons' quest for knowledge and comprehension of India and Indians. For this reason, British perceptions of the subcontinent's architecture are intimately and foundationally linked to Britons' understanding of India. However, few scholars have addressed these architectural perceptions in their own right, which is the purpose of this thesis. An evaluation of scholarly papers, journal and newspaper articles, travel narratives, visual artistic works, history books, museum exhibit and exhibition accounts from the late eighteenth century to the early twentieth reveals that Britons' first introduction to Indian architecture came through the lens of Romanticism. Intellectual and artistic Romantic open mindedness created an environment in which Britons could appreciate and admire the unusual architectural traditions of the subcontinent. However, as the nineteenth century progressed, Romantic inquiry and depictions gave way to scientific methods of investigation and presentation while Britain increasingly committed herself to an imperial role in India. These occurrences worked together to dismantle the Romantic lens of the first introduction and reframe perceptions in the shadow of empire and its inherent Western supremacy. Through the lens of empire and Western supremacy, respect and admiration for Islamic traditions declined in British eyes while Hindu traditions only met with disapproval and disdain when given attention at all. Only the ancient Buddhist monuments of India with their Western aesthetic influences, respected religious association, and lack of native, living followers could Britons look on with high regard.
- ItemGIS-BASED VULNERABILITY MODELING OF SOUTH CAROLINA MARSH HAMMOCKS AND ASSOCIATED SPECIES TO SEA LEVEL RISE(2013-03-08) McCalley, Matthew Owen; Gramling, Joel M; Environmental StudiesHammock islands are low-elevation landforms in coastal marshes that host high biodiversity. Global sea level rise projections over the next century are at levels that will likely inundate many hammock islands. This analysis modeled the effects of accelerated sea level rise (SLR) to 226 hammock islands under three SLR scenarios and provided unique methods for DEM calibration and hydrologic connectivity modeling. The influence of two- and three-dimensional spatial parameters on hammock island species richness was assessed. LiDAR modeled changes in the strongest parameters were used to predict post-SLR species richness. The model indicates that collective island area is reduced by 27.42%, 59.02% and 74.07% for 52 cm, 82 cm and 1.0 m SLR scenarios, respectively. All modeled islands incurred inundation for at least 7% of the island's surface area. 91.6% of islands were >/=50% affected, 56.8% of islands were >/=90% affected and 29.2% of islands incurred complete inundation under the 1.0 m SLR scenario. The variables most strongly associated with species richness were the area of an island (r-squared=64.18) and the volume of an island above mean high water (r-squared=72.81). The relative change and magnitude of change for islands and associated species differed depending on island size. Applying changes in island volume to the predictive function indicated a 2.29%, 10.55% and 17.63% decrease in quartile-derived collective species richness for SLR at 52 cm, 82 cm and 1.0 m, respectively; post-SLR island area indicated an 8.33%, 21.50% and 30.67% decrease in collective species richness respective to the same SLR scenarios. SLR may potentially interact with South Carolina's marsh island regulation, as island size will change over the next century. Conservation efforts must harness active management to promote in-situ habitat resilience at the local scale while urging global greenhouse gas reductions.
- ItemA habitat characterization and suitability model for the endangered wetland plant Lindera melissifolia in the Southeastern Coastal Plain(2013-03-08) Beckley, Anne Cubeta; Gramling, Joel M.; Environmental StudiesLindera melissifolia is a federally endangered wetland shrub endemic to the Southeastern Coastal Plain and the Lower Mississippi Alluvial Valley. Lindera melissifolia is known to occupy temporarily flooded habitats, but little work has been done to describe range-wide habitat characteristics and species distribution in the Southeastern Coastal Plain region. This research utilizes vegetation and environmental data collected from 50 plots in North Carolina, South Carolina, and Georgia to develop a habitat characterization for the Southeastern Coastal Plain. Cluster analysis, nonmetric multidimensional scaling, indicator species analysis, and analysis of variance were used to group and describe plots into four isolated wetland habitat types. Swamp Tupelo Depression Pond and Successional Swamp Forest communities supported the densest and healthiest L. melissifolia populations, followed by Pond-Cypress Pond and Pocosin, and Limestone Sink Forest habitats. A species distribution model was created for L. melissifolia in the Francis Marion National Forest and the Woodbury Wildlife Management Area and Heritage Preserve, both in South Carolina. Results from the model describe habitat parameters and identify areas with a high probability of habitat suitability throughout the study area. A survey of sites with high predicted habitat suitability (≥88.5%) found that 100% of sites supported suitable L. melissifolia habitat, and 23% contained previously unknown populations. Results from the habitat characterization and the habitat suitability model were combined to provide recommendations to regional land managers on habitat suitability assessment, population discovery, and L. melissifolia restoration.
- ItemHOW DO PEOPLE PERCEIVE SCIENTIFIC INFORMATION? A STUDY OF THE COMMUNICATION OF SCIENCE USING THE LOCAL FOOD MOVEMENT IN THE CHARLESTON AREA(2013-03-08) Eichorn, Margaret Elaine; Watson, Annette; Environmental StudiesScience studies has revealed that science is a social process comprised of a variety of actors. Scientists, the public, and the media are responsible for the current state of the communication of science, and they are therefore all held accountable for the interpretations and the misinterpretation of scientific information. The local food movement is one case in which the communication of scientific information has the potential to motivate consumer behavior. The science behind food is comprised of research from the disciplines of biology, chemistry, nutrition, physiology, biotechnology and engineering; however, it is not these food scientists who are deploying this research into the public realm. Rather, media sources are responsible for driving the public discourse of food. If the media adequately communicates information to help people fully grasp the processes involved in producing local food, it may alter both their behaviors. Using the qualitative methods of participant observation, discourse analysis, and focus groups, along with descriptive statistics of focus group participants, this project aimed to assess the efficacy of the communication of science using the local food movement. This project revealed how different social groups perceive information about food production and assessed which communication methods are most effective throughout social groups in Charleston. Different discourses, such as "hindrances," "community concern," "convenience," and "skepticism" emerged from members of these groups. However, members of all social groups within my study agreed that media sources with images, such as documentaries, are most effective in inciting behavioral changes. These results offer suggestions for how local food leaders in Charleston area should best advertize local food sources to motivate consumers in the area to participate in the local food movement.
- ItemIncubation Temperature Effects on Hatchling Performance in the Loggerhead Sea Turtle (Caretta caretta)(2013-03-08) Fisher, Leah Rachel; Owens, David Wm.; Marine BiologyIncubation temperature has significant developmental effects on oviparous animals, including determining sex for several species. For the Northwest Atlantic loggerhead sea turtle (Caretta caretta), apparent population-wide female-biased hatchling sex ratios contrast with observations of juvenile populations, where sex ratios have remained constant at about 2 to 1 female-biased over the past 30 years. It has been suggested that some unknown factor is affecting loggerhead survival resulting in an unexplained differential loss of ~60% of female hatchlings per year. One theory to explain this hatchling mortality is tested in this project, that incubation temperature affects traits that influence survival. Furthermore, there may be differential survival between male and female hatchlings. I conducted laboratory experiments to test for an effect of incubation temperature on performance of loggerhead hatchlings. I tested 68 hatchlings produced from eggs incubated at 8 different constant temperatures ranging from ~27ºC to ~32.5ºC. Following their emergence from the eggs, I tested righting response, crawling speed, and conducted a 24-hour long hatchling swim test. Data indicate an effect of incubation temperature on survivorship, righting response time, crawling speed, change in crawl speed, and overall swim activity, with hatchlings incubated at 27ºC showing decreased locomotor abilities. No hatchlings survived when incubated at 32ºC and above. Differences in survivorship of hatchlings incubated at high temperatures are important in light of projected higher sand temperatures due to climate change, and could indicate increased mortality from incubation temperature effects.