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

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.

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.