Understanding the movements and behavior of hawksbi1l sea turtles is vital to their protection, but existing data on these subjects are insufficient. The objectives of this study were 1) to monitor internesting movements and surfacing behavior of hawksbill sea turtles nesting at Buck Island Reef National Monument, St. Croix, and 2) to describe post-nesting movements of Buck Island hawksbills. Surfacing behavior and presence or absence of tagged turtles W(> :-t' monitored 24 hr a day by a computerized tracking system using pulse-coded transmitters. Internesting and post-nesting movements were tracked using satellite transmitters on the ARGOS system. No clear trends were apparent in total time spent at the surface. either during an internesting interval or when comparing day and nigh~ behavior; behavior was turtle and interval-specific (n=3). The number of times a turtle surfaced over an internesting interval also varied among turtles, but all turtles surfaced more frequently at the end of an internesting interval (P < 0.05). No differences were found in the number of times turtles surfaced during the day versus night, with the exception of one turtle which surfaced more frequently during the daytime. Comparisons of day and nighttime activity among turtles revealed that surfacing behavior was similar among the turtles studied with the exception of one turtle that spent significantly more time at the surface than the other turtles during both day and night. Internesting movements were found to be extensive for 2 of 3 turtles tracked t with turtles moving from 197 km to 845 km from Buck Island. The third turtle remained within 1 km of Buck Island. Tagged turtles left the Buck Island vicinity immediately after nesting for the season. Two turtles tracked with pulse-coded transmitters through the end of their nesting effort were last heard less than 24 hr after laying their last nest. Satellite tagged turtle T3, tracked for 10 months, traveled between the British Virgin Islands and Puerto Rico for 3 months, then became resident off the southern coasts of St. Thomas and St. John, USVI. Turtle T3 left this area occasionally on short-duration excursions, but always returned. Satellite tagged turtle T8, tracked for 1.5 months, moved to Puerto Rico immediately after completing nesting for the season, and was subsequently located off the coast of the Dominican Republic t St. Vincent (The Grenadines), and the northern coast of Venezuela. A third turtle (TIl) was located only once after laying her last nest; at the island of Anegada, BVI. Frequent failure to receive locations from satellite transmitters that were known to be attached and functional suggests that turtles may not stay at the surface long enough for transmissions to reach the ARGOS satellites. / Master of Science

South Florida's loggerhead (Caretta caretta), green (Chelonia mydas) and leatherback (Dermochelys coriacea) sea turtles hatchling have environmentally determined sex. The in situ nest mean hatchling sex ratios (SR) were highly female-biased : loggerhead F=0.89) and green turtle F=0.81; leatherback's SR was nearly balanced (0.55F). Nest temperatures and SRs differed between leatherbacks and loggerhead and green turtles. The latter two did not differ. The loggerhead response parameters were estimated within biological limitations by both 50-65% of incubation and mean middle 1/3 temperature. The maximum middle 1/3 temperature was the best-fit predictor for green turtles. No best-fit sex ratio-temperature response could be identified for leatherbacks. Clutches incubating under natural conditions can vary greatly in SR ; TRT differences may account for differences among species' sex ratios. / by Micah Marie Rogers. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

The red imported fire ant, Solenopsis invicta, is a South American native introduced in Alabama in the early 20th century. This predatory species has rapidly spread throughout the southeastern US and parts of the West Indies, inflicting great ecological and economic damage. For example, Solenopsis invicta is known to attack the eggs and hatchlings of ground nesting birds and reptiles. The ants swarm into the nests attacking hatchlings and diminishing their chance for survival. My thesis research aimed to survey the distribution of ants on sea turtle nesting beaches in South Florida and St. Croix, USVI, and to evaluate the possible threat of Solenopsis invicta and other predatory ants to sea turtle hatchlings. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2013.

Juvenile green turtle (Chelonia mydas) abundance differs among nearshore reefs, but why some sites are preferred over others is unknown. My study had two objectives: to quantify differences in abundance over time (one year) and to determine what ecological factors were correlated with those differences. I conducted quarterly surveys on reefs in Palm Beach and Broward Counties and compared reef sites with respect to (i) water depth, (ii) algal abundance and composition, and (iii) changes in reef area (caused by sand covering) through time (11 years). Turtles were most abundant on shallow reefs exposed to high light levels that remained stable (uncovered by sand) for long periods of time. These reefs had the highest diversity of algal species, in part because cropping by the turtles prevented any one species from becoming dominant. My results suggest that both physical and biological factors make some reefs more attractive to turtles than others / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2013.

This dissertation examined the natal origins, home-range, and in-situ foraging behavior of an aggregation of sub-adult hawksbill turtles (Eretmochelys imbricata) found off the coast of Palm Beach County, Florida. Surveys were conducted on approximately 30 linear km of reef between 15 and 30 m in depth. Tissue samples were retrieved from 112 turtles for mtDNA haplotype determination. GPS-linked satellite transmitters were deployed on six resident sub-adults, resulting in both minimum convex polygon (MCP) and 95%, 50%, and 25% kernel density estimates (KDE) of home-range size. A foraging ethogram was developed, and sequential analysis performed on thirty videos (141 total minutes) of in-situ foraging behavior. Seventeen total haplotypes were identified in this aggregation, the majority (75%) of which represented rookeries on Mexico’s Yucatan Peninsula. Other sources, from most to least important, include Barbados, Costa Rica, Puerto Rico, Antigua, and the U.S. Virgin Islands. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

Loggerhead (Caretta caretta) and green (Chelonia mydas) turtles recruit to nearshore environments as juveniles. These often degraded habitats are associated with emerging diseases such as green turtle fibropapillomatosis (GTFP), however there are few studies on immune function in sea turtles. The objective of this research was to quantify phagocytosis of the innate immune system by flow cytometry and compare levels between animals from a degraded habitat (the Indian River Lagoon, FL) to a more pristine environment (the Trident Basin, Port Canaveral, FL), and across a range of temperatures. While in vitro temperatures did not alter rates of phagocytosis, it was higher in samples obtained in the summer than winter. Rates of phagocytosis in sea turtles with GTFP and from degraded environments with increased prevalence of GTFP were low compared to animals from the more pristine environment, suggesting that the environment can alter innate immunological function and thus contribute to the development of disease. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

The reproductive success of leatherback turtles (Dermochelys coriacea) is typically the lowest of the seven sea turtle species. Why this vital rate is decreased has remained unanswered for nearly a century. Recently, detailed postmortem examination of leatherback hatchlings identified muscular pathologies that suggested possible selenium deficiency. High bodily burdens of mercury compounds are associated with selenium depletion. Selenium is a necessary detoxifying nutrient that itself can be toxic at elevated concentrations. Mercury compounds are toxicants with no known biological function. High bodily concentrations of mercury can be detrimental to marine organismal health, reproduction and survival, both directly and indirectly through inducing selenium depletion. The goals of this dissertation are to evaluate several related hypotheses to explain low leatherback nest success. ... Because leatherbacks take in high volumes of prey, high tissue concentrations of mercury and selenium can result. This study provides the first evidence that chemical contaminants may explain low reproductive success in leatherback sea turtles. / by Justin R. Perrault. / Thesis (Ph.D.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

In sea turtles, the study of the etiology and development of fibropapillomatosis is not fully understood. Sea turtle fibropapillomatosis is a disease characterized by the proliferation of skin fibropapillomas and occasional internal fibromas. In this study, sea turtle fibropapilloma tumor and healthy tissue samples were used to look at VEGF, BCL-2 and Bax expression. Cancer tumors have a well established pattern of protein expression that involves overexpression of vascular endothelial growth factor (VEGF), responsible for the growth of new blood vessels, and a high BCL-2 to Bax ratio that leads to uncontrolled cell proliferation. Real time PCR was used to analyze VEGF expression, and Western blot techniques were used to measure BCL-2 and Bax expression. The results indicated that expression of VEGF was not significantly higher in tumor vs. skin tissue. For the differential expression of BCL-2 and Bax, the results were not in agreement with the established levels found in cancer studies, showing no significant change in BCL-2 expression and significantly higher levels of Bax in tumor vs. healthy tissue. / by Angela Bancalari-Schmidlapp. / Thesis (M.S.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

Climate change is threatening biodiversity, causing populations and species to adapt, or otherwise, become extinct. Sea turtles have survived dramatic climate changes in the past, however, due to a history of intense human exploitation, and the current anthropogenic threats, their current resilience may be jeopardized. The main pursuits of this thesis were to i) evaluate the resistance of green turtles to predicted climate change impacts, using a globally significant rookery, in Poilão, Guinea-Bissau, as a case study; and ii) assess key population parameters to inform the conservation management of this resource. As the work developed I additionally had the opportunity to study the dynamics of an emerging disease in a juvenile foraging aggregation from Puerto Rico, which contributed to a broader understanding of resilience in this species. Specifically, I investigate the nest site selection behaviour of green turtles, their nesting environment, and the outcomes for their offspring, at Poilão, and apply this information to infer on the resilience of this population under future scenarios of climate change. I explore the connectivity established by the dispersal of post-hatchlings from Poilão, followed by their recruitment to foraging grounds, to set the geographical context of this major population. Lastly, I model the dynamics of Fibropapillomatosis, which affects juvenile green turtles globally, and examine the potential for disease recovery. The green turtle rookery in Poilão shows some resilience to expected climate change impacts. This significant population likely contributes to all juvenile foraging aggregations along the west coast of Africa, and to some extent to those in South America. Currently, green turtles are capable of recovery from Fibropapillomatosis, however, the incidence of disease may be enhanced by climate change.

This thesis discusses both theoretical and practical considerations inherent in conducting community-based research within a case study of sea turtle conservation in Baja California, Mexico. A brief background, including the general ecology, status and distribution of sea turtles of the Baja peninsula is presented, with an overview of the current and historic use and management of sea turtles. Several sets of theories provide the context within which the case example is analyzed. A discussion of how concepts of "science" and "knowledge" are shaped and how these perceptions impact choices made in natural resource management and planning is presented. This includes a brief discussion of conservation ethics and conservation rationale, as well as a review of the debates surrounding indigenous knowledge and its application in conservation. A review of community-based efforts in sea turtle conservation is also presented. The data and analysis offered in this thesis is the result of two field seasons working as a member of an interdisciplinary sea turtle conservation team: conducting biological studies, surveys, informal and semi-structured interviews and participant observation. The major goal of this research project was to evaluate a people-oriented approach to conservation. The objectives of the Baja sea turtle conservation project included: the involvement of fishing communities in the development of conservation projects, the involvement of local students and fishermen in the collection of data and the public sharing of research results on a regular basis. Results of this case study suggest that through dependence on the host community for food, equipment, labor and guidance a special connection was established, fostering trust and building the partnerships necessary for long-term conservation success. For this reason, fishermen and other members of the local host communities were more willing to cooperate with outsiders and share their intimate knowledge of their environment - including information on the daily movements and distribution of sea turtles. It is crucial that the fishermen feel empowered before they choose to participate in the sea turtle conservation efforts. They must be viewed, and view themselves, as an integral part of the conservation team contributing valuable knowledge and ideas, not just acting as boat drivers and guides for outside researchers within the host community. Community meetings served as an outlet to voice concerns and share information. The active involvement and participation of local communities is a highly effective tool in the sea turtle conservation efforts in the region. / Graduation date: 2002