Thesis (M.A.)--Wheaton College Graduate School, 2002. / Abstract. Includes bibliographical references (leaf 41).

Thesis (M.A.)--Wheaton College Graduate School, Wheaton, IL, 2002. / Abstract. Includes bibliographical references (leaf 41).

Thesis (M.A.)--Wheaton College Graduate School, Wheaton, IL, 2002. / Abstract. Includes bibliographical references (leaf 41).

Ocean acidification and warming have been shown to affect a wide range of marine organisms and impact assemblages and ecosystems. Many of the species experiencing negative biological effects provide valuable ecosystem services, yet it is unclear how these biological effects will affect ecosystem services provision. This thesis aimed to appraise the consequences of ocean acidification and warming on important shellfish species, from physiology to provision of ecosystem services, using a multidisciplinary approach. The responses to ocean acidification and warming of two ecologically and commercially important species of oysters – the native European Flat oyster Ostrea edulis, and the non-native Pacific oyster Magallana gigas – were assessed in laboratory mesocosms following long-term exposures to a range of scenarios predicted for 2050 and 2100. Oysters provide numerous ecosystem services, including improvement of water quality, reef formation, and food provision, but are at risks from ocean acidification and other stressors due to negative impacts occurring at multiple life-stages and threatening reef maintenance and functioning (Chapter 1). The physiology of adult oysters appeared susceptible to ocean acidification and warming, with evident sub-lethal effects (Chapter 2). Magallana gigas experienced a greater degree of stress than O. edulis, displaying increased Standard Metabolic Rate, reduced Clearance Rate, and poorer Condition Indices. Reductions in Clearance Rates of M. gigas are especially concerning and may have important ecological impacts by limiting their ability to improve water quality in the future. The physiological changes experienced by individual oysters held important implications for the functioning of the reefs through changes in predation resistance. Again, M. gigas appeared to undergo more pronounced changes than O. edulis, displaying increased muscle strength but weakened shell strength. These changes are expected to alter its susceptibility to predators and influence community level interactions. Both O. edulis and M. gigas also underwent important changes to their biochemical composition with trends for impoverished nutritional quality, which holds direct implications on the provision of sea food. In particular, M. gigas contained lower lipid, carbohydrate, and protein levels, but higher contaminant concentration (copper); this change holds concerns for both future food security and future food safety. It was apparent that the physiological stress experienced (Chapter 2), led to significant energy reallocation from somatic growth to metabolism by depleting energetic reserves (Chapter 4), at the detriment of its nutritional quality. No negative effects on the eating quality of M. gigas (appearance, aroma, texture, taste, and overall acceptability) were recorded following a short-term exposure to ocean acidification and warming (Chapter 5), which was considered positive for the aquaculture sector. In order to secure future food provision and economic revenue, the UK aquaculture industry might need to reconsider its management strategy in the future, and encourage the production and consumption of O. edulis, in addition to the already popular M. gigas. It is clear that the impacts of ocean acidification and warming on oysters are multifaceted and occurring at multiple scales and levels of organisation. The risks to oysters and oyster reefs appear species-specific; in the UK, introduced M. gigas may be more vulnerable than native O. edulis. To secure benefits and minimise costs related to the management of introduced species, these findings could be integrated into the current management and conservation measures in place for these species and the reefs they can form.

Title from PDF of title page. / Document formatted into pages; contains 105 pages. / Thesis (M.S.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Relative plate motion history since 30 Ma between the Pacific and the southern portion of the Nazca (Farallon) plates is examined. The history is constrained by available seafloor magnetic anomaly data and a two-minute grid of predicted bathymetry derived from satellite altimetry and shipboard sensors. These data are used to create a new plate motion reconstruction based on new magnetic anomaly identifications and finite poles of motion. The new identified magnetic isochrons and tectonic reconstruction provides greater resolution to the tectonic history between chrons 7y (24.73 Ma) and 3 (4.18 Ma) than previous interpretations. Shipboard magnetics and aeromagnetic data from over 250 expeditions were plotted and used to extrapolate magnetic anomalies picked from 2D magnetic modeling from selected cruises. Magnetic anomalies were further constrained by tectonic features evident in the predicted bathymetry. / ABSTRACT: Previously published magnetic anomaly locations consistent with this work were used where interpretation could not be constrained by 2D modeling and map extrapolation. Point locations for anomalies were used as input for calculation of finite poles of motion for chrons 10y, 7y, 6c, 5d, 5b, 5aa, 5o, 4a and 3a. An iterative process of anomaly mapping, pole calculation and anomaly point rotations was used to refine the finite poles of motion. Eleven stage poles were calculated from the nine finite poles from this study and two published instantaneous Euler vectors. Tectonic reconstructions indicate a history dominated by two major southward ridge propagation events, the first starting by 28 Ma and completed by 18 Ma. The second event initiated in association with breakup of the Farallon plate around 24 Ma and ceased by about 11 Ma. Lithosphere was transferred from Nazca to Pacific during the first event and in the opposite sense during the second. / ABSTRACT: Development of the Mendoza microplate east of the later propagator occurred at about 20 Ma and this dual spreading process appears to have lasted until about 15 Ma. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Title from PDF of title page. / Document formatted into pages; contains 93 pages / Thesis (M.S.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Coral-based climate studies commonly use elemental ratios and stable isotopes of coral skeletons to address seawater temperature and hydrologic balance issues in the tropical surface oceans. Replication, or cross-checking, a standard technique used to assess the fidelity of proxy records in paleoclimatology has not been widely applied in coral-based climate studies, primarily because of the time and cost associated with generating multiple records from a single reef site. Modern and paleoclimate reconstructions based on a single proxy-coral record from a site may contain errors if individual corals from the same reef record different geochemical signals. In this study we perform a replication test using elemental ratios and stable isotopes in three Porites corals from New Caledonia. / ABSTRACT: The reef complex offshore Amédée Island, New Caledonia is an ideal site to perform a coral replication test because instrumental sea surface temperatures (SST) and sea surface salinity measurements (SSS) have been made there for over 25 years. In this study, we compare sub-monthly resolved, geochemical variations (Sr/Ca, d18O and d13C) in three Porites lutea coral heads, located 500 m apart, with the instrumental SST and SSS records over the interval 1992-1967. The monthly coral Sr/Ca and d18O time series are well correlated to each other (r=0.86, p[.0001) and to the monthly instrumental SST record (r= -0.86, p[.0001, coral Sr/Ca to SST; r= -0.77, p[.0001, coral d18O to SST). The three, sub-monthly resolved, 30-year coral Sr/Ca-SST time series have mean SST values that agree within 0.2oC with the instrumental mean SST value. A similar comparison for the coral d18O-SST records indicate a maximum difference between predicted and observed mean SST of 0.5°C. / ABSTRACT: Analysis of the monthly climatological means also indicates that Sr/Ca-SST records closely match the instrumental SST record ±0.4°C; a similar comparison using the d18O-SST record yields an average offset of ±0.6°C between observed and predicted monthly SST. Stacking the three records to form composite Sr/Ca-SST and d18O-SST records does not appreciably improve the goodness of fit between the proxy and instrumental SST records; hence a coral-based proxy climate record from a single coral accurately reflects the observed record of climate variability at this locality. These results support the concept that high fidelity climate records can be generated using a single coral core. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 210-214). Also available on the World Wide Web.

Rising temperature caused by global warming alters physiology, phenology and/or distribution in a wide array of plant and animal species, which has dramatic knock-on effects at different levels of organisation. This study investigates the individual and interactive effects of temperature (18ᵒC, 22ᵒC and 30ᵒC) and additions of the macroalga Gracilaria gracilis (high and low) on the performance of the seagrass Zostera capensis, which occurs in Langebaan Lagoon, South Africa over a seven-week period. Results from the laboratory experiment revealed that G. gracilis did not significantly affect the performance of Z. capensis although temperature did result in greater leaf width, fouling and senescent biomass, as well as marginally greater leaf area and lower below-ground biomass at 30ᵒC. Increasing temperature also increased G. gracilis biomass, percent cover and fouling by microalgae. In addition, there was no interaction between temperature and the additions of Gracilaria. The overall findings of this study indicate that Z. capensis abundance is likely to decrease while G. gracilis will conversely increase in abundance in response to warming. Changes in abundance of those two ecosystem engineers highlight the possibility of a phase shift from a seagrass- to macroalgal-dominated state in Langebaan Lagoon.

Factors in the Admissions Process Influencing Persistence in a Master’s of Science Program in Marine Science. Melissa L. Dore, 2017: Applied Dissertation, Nova Southeastern University, Abraham S. Fischler College of Education. Keywords: academic persistence, admission counseling, graduate students, marine science education, examinations This applied dissertation was conducted to provide the graduate program in marine sciences a valid predictor for success in the admissions scoring systems that include the general Graduate Record Exam. The dependent variable was persistence: successfully graduating from the marine sciences master’s programs. This dissertation evaluated other values including the applicant’s age, gender, undergraduate GPA, letters of recommendation, and acceptance level (Accepted with Academic Requirement (probation) or Full Acceptance). The writer statistically showed that two values proved most significant in defining a student’s persistence: undergraduate major GPA and age when entering the program. An analysis of the data allowed the marine science master’s programs to develop an index to assist students to succeed in the program as well as reduce the time to completion.

Includes vita. / Title from PDF of title page. / Document formatted into pages; contains 119 pages. / Thesis (Ph.D.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The air-sea interaction thermodynamics of the western equatorial Pacific, the Earth's largest region of warm SST, is a major component of the global climate system. Along the equator, warm pool thermodynamics and momentum are influenced by equatorial ocean visco-inertial boundary layer dynamics that occur within a few degrees of the equator because of the sign reversal of the Coriolis force. Designed to study this system, COARE Enhanced Monitoring Array (EMA) observations of temperature, salinity, velocity, and surface meteorology were centered at 0, 156°E from February 1992 through April 1994. They sampled variability on the equator over larger space/time-scales than the concurrent Intensive Flux Array (IFA) centered at 2°S, 156°E. The EMA data are examined within the context of the larger scale equatorial Pacific and the El Niño conditions that occurred at that time. / ABSTRACT: There is a structural change in the equatorial Pacific near the dateline resulting from the winds that are strong, steady, and easterly in the east and generally weak, punctuated by westerly wind bursts, in the west. East of the dateline the EUC's speed and transport increases downstream, while in the west it tends to be zonally uniform, consistent with the extra-tropical ocean interior water pathways that tend to converge on the equator east of the dateline. At 0°, 156°E in the western Pacific deep, seasonal upwelling (appearing stronger after the peak of the 1991/92 El Niño than during the following weaker El Niño year) occurs within the thermocline in boreal summer with magnitudes as large as upwelling in the eastern Pacific cold tongue. This large upwelling is associated with large downward turbulent heat flux and large turbulent shear stress. / ABSTRACT: While the inferred mixing is quantitatively inconclusive because of unresolved potential errors, it is consistent with the visco-inertial boundary layer concepts from early theory [e.g. Arthur 1960; Robinson 1960; Stommel 1960; and Charney and Spiegel 1971]. These findings suggest that the equatorial thermodynamics differ from those of the IFA. Further process experimentation is necessary to quantify these results. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.