Information on the locations for feeding, reproductions, and resting, are essential to effectively protect sea turtle populations and implement conservation efforts. This type of ecological information is critically important for hawksbill turtle conservation in Los Roques Archipelago National Park (LRANP) where turtles have been declining in spite of habitat protection efforts. The goal of this research was to produce a benthic habitat map of LRANP employing in situ visual surveys, remote sensing and geographic information system techniques, and to spatially characterize sea turtle occupancy and patterns of usage by habitat type. Between June and August of 2008, turtle behavior and habitat use were recorded during 159 h of observation, comprising 46 sighting events (n = 20 juveniles, n = 26 female adults). Observed activities were grouped into 4 categories: foraging, resting, swimming, and reproductive behavior. The benthic habitat at each turtle sighting was recorded as one of three categories: coral reef, sand or marine vegetation. Results suggest that the population of turtles within LRANP is comprised primarily of female adults and juvenile individuals and that coral reef is the most important habitat for this species. The most important foraging area in the atoll is a coral patch reef that connects Dos Mosquises Sur and Dos Mosquises Norte. The data in this thesis have been made available in digital and map form to the managers of LRANP for management purposes.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 86-91). Also available via the Internet.

Theses (M.S.)--University of Hawai'i at Hilo, 2009. / Advisor : Jason Turner. Bibliography : p.28-30.

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

The beaches in the Gandoca-Manzanillo National Wildlife Refuge (GMNWR) in southeastern Costa Rica are known to host nesting critically endangered hawksbill sea turtles (<i>Eretmochelys imbricata</i>). The spatial ecology and movement behaviors of this nesting population has never been observed. Evaluating the spatial ecology of nesting sea turtles allows for a better understanding of their local movement behavior as well as their large scale oceanic movements that inform conservation needs. Satellite tracks reveal internesting, postnesting migration, and foraging behaviors for four nesting hawksbills from the GMNWR. During the internesting behavior, satellite-tracked hawksbills remained in the coastal waters near the nesting beach for 15 to 55 days before making their postnesting migration. Home-range areas occupied by internesting hawksbills vary between 21.9 and 557.9 km². Hawksbill internesting high use areas overlapped with the marine boundary of the GMNWR for an average of 29% of time spent inside the refuge. The beginning of all four turtle’s migrations start with a pelagic circular movement away from the coast into the Caribbean Sea before resuming a northern coastal migration pattern. Migration routes varied in length from 662 to 1,486 km and passed through three or four exclusive economic zones of various neighboring nations. Foraging areas of three hawksbills were situated east of Nicaragua and one was found along the northern coast of Honduras, near Roatan. Foraging home-range areas of satellite-tracked hawksbills varied from 205.1 to 696.1 km². This is the second satellite telemetry study completed on nesting hawksbills in the Costa Rican Caribbean and the first for GMNWR. These results display the use of pelagic and coastal migratory routes for the critically endangered hawksbill. Distant foraging grounds utilized by hawksbills nesting in Costa Rica reveal the importance for the preservation of the Miskito Cays and nearby ecosystems.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-08-22T13:31:42Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação - Thyara Noely Simoes.pdf: 1606100 bytes, checksum: a1162b67299a1fb757baa997c7f7ae73 (MD5) / Made available in DSpace on 2016-08-22T13:31:42Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação - Thyara Noely Simoes.pdf: 1606100 bytes, checksum: a1162b67299a1fb757baa997c7f7ae73 (MD5) Previous issue date: 2016-03-16 / CAPEs / Neste estudo, sangue de fêmeas, cascas de ovos e sedimento do ninho de tartarugas Eretmochelys imbricata coletados durante o período reprodutivo, foram analisados por Fluorescência de Raios X para determinar a presença e as concentrações de Ni, Co, Cu, Hg, Pb e Cr e sua possíveis interferências em alguns aspectos reprodutivos. Todos os elementos foram detectados em baixas concentrações. O Ni foi o elemento encontrado em maiores concentrações nas três matrizes; enquanto o Hg foi encontrado em menores concentrações. As análises demonstraram relação positiva (p<0,05) entre o número de ovos que não eclodiram e a concentração de Cu e Pb no sangue. No entanto, os metais não tiveram influência na produção dos ovos nem na mortalidade dos neonatos; tampouco houve relação direta na transferência materna para as cascas. Assim, metais pesados podem ter alguma influência na reprodução da espécie, mesmo em baixas concentrações. Em concentrações maiores, estes poluentes podem ser importantes limitantes da reprodução de tartarugas marinhas. / In this study, blood, egg shells, and nest sediments of sea turtles Eretmochelys imbricate, collected during reproductive period, were analyzed by X- Ray fluorescence to determine the presence and concentrations of Ni, Co, Cu, Hg, Pb and Cr and their possible interference in some reproductive data. All elements were detected in low concentrations. Ni has been found in higher concentrations in three matrices; while Hg was found in lower concentrations. Our analyses demonstrated significant relationship (p < 0,05) between the unhatched eggs and blood concentrations of Cu and Pb. However, the metals did not have influence on egg production nor on newborn mortality; furthermore, no evidence of transference from mother to eggshells was found. Thus, heavy metals may have some influence on the reproduction of Eretmochelys imbricata, even at low concentrations. In higher concentrations, these pollutants may have important influence in reproduction of sea turtles.

Marine turtle conservation is most successful when it is based on sound data incorporating life history, historical population stability, and gene flow among populations. This research attempts to provide that information through two studies. In chapter I, I identify historical patterns of gene flow, population sizes, and contraction/expansion during major climatic shifts. In chapter II, I reveal a life history characteristic of loggerhead turtles previously undocumented. I identify a pattern of juvenile recruitment to foraging grounds proximal to their natal nesting beach. This pattern results in a predictable recruitment pattern from juvenile foraging ground aggregations to local rookeries. This research will provide crucial information to conservation managers by demonstrating how sensitive marine turtles are to global climate change. In the second component of my research, I demonstrate how threats posed to juvenile foraging grounds will have measurable effects on rookeries proximal to those foraging grounds. The addition of this basic life history information will have dramatic effects on marine turtle conservation in the future, and will serve as the basis for more thorough, forward-looking recovery plans.

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

The younger life history stages of marine turtles (eggs, hatchlings) often fail to survive. To compensate, sea turtles nest several times/season and produce large clutches of eggs. The hawksbill produces the largest clutches (150 eggs) and the smallest hatchlings of any marine turtle. My study, done at Jumby Bay in Antigua, West Indies, was designed to determine whether they did so to compensate for loss in the nest, hatchling loss in the water, or both factors. I found that most of the eggs (79 %) survived to become hatchlings that left the nest and entered the sea. However, 88 % of the hatchlings swimming offshore were taken by predators within minutes after they began their migration. These results suggest that at Jumby Bay, large clutch size is favored in hawksbills because of predation pressures on the hatchlings. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2013.

Sedimentary characteristics of grainy non-skeletal tidal flats along windward platform margins have not been described in modern environments and may be misidentified or misclassified in the rock record. This study describes the sedimentology of such an environment to aid in accurate identification and characterization in the ancient. At Shroud Cay, a grain-dominated tidal flat is sheltered from the high energy of the shelf by a ring of cemented Pleistocene and partly indurated Holocene eolianite islands separated by several narrow tidal passes. Depositional texture, environment of deposition and geobody mapping, extensive sediment sampling, and vibracoring have shown that, though the cemented island provide a barrier from the high energy of the shelf, a high degree of tidal energy still occurs behind this barrier as indicated by the overwhelmingly grainy nature of all of the tidal flat sub-environments. Intertidal flats comprise the majority of the tidal flat surface. These flats are characterized by patchy Scytonema mats overlying bioturbated peloid-ooid grainstones to packstones with cemented lithoclasts. Three main tidal channels dissect the tidal flat and allow diurnal flow, one of those tidal channels does not exit the tidal flat but dead-ends behind a cemented Holocene beach dune ridge along the eastern side of Shroud Cay. Peloid-ooid-skeletal grainstone tidal bars and peloid-ooid packstones fill much of the channels. Most of the channels are bordered by low-relief grain-rich packstone levees often capped by red mangroves and algal mats. The interior-most supratidal parts of the flat, often in the lee of the windward Holocene ridge, are covered by a thick (5-~25cm) Scytonema microbial mat underlain by grain-rich ooid-peloid packstones. Ancient grain-dominated carbonate tidal flats and eolianite deposits like Shroud Cay?s are the reservoir rocks in some of today?s largest hydrocarbon fields. We develop a model for the evolution of the grain-dominated tidal flat, document and compare differences between the grain-rich tidal flat and surrounding environments of deposition, and develop a set of criteria for recognition. These criteria can be used to more accurately characterize reservoirs such as the Jurassic Smackover fields, to avoid mis-classification of similar settings, and more effectively produce those reservoirs.