<p>An understanding of sensory ecology, how animals receive and respond to their environment, can be a powerful tool for the conservation of endangered species because it can allow us to assess the potential success of actions designed to mitigate particular threats. We have a general understanding of how sea turtles perceive and respond to certain visual, magnetic, and chemical cues, but we understand very little about how they perceive and respond to acoustic cues. This dissertation explores the acoustic ecology of sea turtles, focusing on their auditory capabilities, responses to acoustic stimuli and the implications of this knowledge for their conservation. I measured the underwater and aerial hearing sensitivities of juvenile green (Chelonia mydas), hatchling leatherback (Dermochelys coriacea), and hatchling hawksbill (Eretmochelys imbricata) sea turtles by recording auditory evoked potential responses to tonal stimuli. Green turtles detected tonal stimuli between 50 and 1,600 Hz underwater (maximum sensitivity: 200-400 Hz) and 50 and 800 Hz in air (maximum sensitivity: 300-400 Hz), leatherbacks detected tonal stimuli between 50 and 1,200 Hz underwater (maximum sensitivity: 100-400 Hz) and 50 and 1,600 Hz in air (maximum sensitivity: 50-400Hz), and hawksbills detected tonal stimuli between 50 and 1,600 Hz in both media (maximum sensitivity: 200-400 Hz). Sea turtles were more sensitive to aerial than underwater stimuli when audiograms were compared in terms of sound pressure, but they were more sensitive to underwater stimuli when audiograms were compared in terms of sound intensity. I also examined the behavioral responses of loggerhead sea turtle (Caretta caretta) to simulated low frequency acoustic deterrent devices (ADDs) and found that these turtles exhibited a mild, aversive response to these sounds. This finding indicates that low frequency tonal ADDs have the potential to warn sea turtles of the presence of fishing gear and suggest that field tests of ADDs are warranted. Finally, I conducted a comprehensive review of our knowledge of the acoustic ecology of sea turtles, examined the sources of marine anthropogenic sound sea turtles are able to detect, evaluated the potential physiological and behavioral effects of anthropogenic sound, identified data gaps, and made recommendations for future research.</p> / Dissertation

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2017-08-03T12:45:39Z No. of bitstreams: 1 PDF - Clenia Maria Pereira Batista.pdf: 13351762 bytes, checksum: 39628b015e1f0b5966d30cd5bdccc136 (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2017-08-29T15:43:28Z (GMT) No. of bitstreams: 1 PDF - Clenia Maria Pereira Batista.pdf: 13351762 bytes, checksum: 39628b015e1f0b5966d30cd5bdccc136 (MD5) / Made available in DSpace on 2017-08-29T15:43:28Z (GMT). No. of bitstreams: 1 PDF - Clenia Maria Pereira Batista.pdf: 13351762 bytes, checksum: 39628b015e1f0b5966d30cd5bdccc136 (MD5) Previous issue date: 2013-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Solid debris incorrectly thrown away become enviromental contamination. Sea debris are one of the main problems for coastal environments worldwide, causing death to many species of its fauna. Debris can affect over 267 species of marine animals wordwide, including 86% of all species of marine turtles. Natural characteristics of their biology make marine turtles specially fragile to such human impact. The marine turtle’s feeding and nesting areas on the coast of Paraíba are conspicuously impacted due to debris coming from different origins, such as coastal activities from local populations and tourists, carried from estuary draining (croming from urban areas) and direct discharge on open sea by comercial and touristic boats. Such impact is a potential cause of death to over 100 marine turtles per year. The ingestion of those materials, causing obstruction of the digestive tract is the main negative interaction registered. Searching for relations between the kinds of debris found on the beaches, foraging sites and stomach content from marine turtles, this study intends to quantify and profile the solid debris found on the beach, the ocean and the digestive tracts of marine turtles. Samplings were performed at sea and six beaches on the state of Paraíba as well as the analysis of 26 gastrointestinal contents of marine turtles (from a total of 200 samples), that had antropic residues on its contents. Sea samplings were performed at Parque Estadual da Ilha de Areia Vermelha (PEMAV) and Picãozinho. The solid debris found on stomach contents were provided by systematic collects realized by the field team of the Guajiru NGO between 2009 and 2012. During the study, a total of 20,700 itens, being 68.904 kg of debris collected – 13,210 itens at beach, 8 on the foraging sites and 7,482 on marine turtles. Plastic corresponded to 60.85% of the itens collected, being 25.17% of the total weight , followed by organic matter 10.13% and nylon 9.85%. the beaches with biggest quantities of debris were the ones with >50 thousand inhabitants, with 6,080 itens (29.37%) of the total sampling and the gastrointestinal contents of marine turtles presented the biggest quantity of solid residues with 7,482 itens (36.14%). Of all marine turtles collected, 16 presented CCL >35 cm and had 3,649 plastic itens on their gastrointestinal tracts, being 3,220 flexible plastic materials and 429 rigid plastic. These data can be applied on integrated coastal management plans, aiming to erradicate the presence of debris and pollution from the oceans. The results demonstrate that the debris on foraging areas have direct antropic origin due to touristic visiting, debris on the beaches are origined by continental draining, direct discharge on the ocean by comercial and touristic ships and principally due to local population and tourists, and that the debris found on marine turtles are not just from the continent, but a result of all the influx of such materials to the ocean. / Resíduos sólidos erroneamente descartados produzem contaminação no meio ambiente. O lixo marinho é um dos principais problemas nos ambientes costeiros em todo o mundo, causando a morte de espécies da fauna. Esses resíduos podem afetar ao menos 267 espécies de animais marinhos em todo o mundo, incluindo 86% de todas as espécies de tartarugas marinhas. Características naturais da biologia das tartarugas marinhas tornam essas espécies ainda mais frágeis perante essa ação humana. As áreas de alimentação e anidação de tartarugas marinhas no litoral da Paraíba se encontram impactadas devido ao lixo com diversas origens, tais como aqueles advindos de atividades costeiras da população local e turistas; aquele aportado pela drenagem dos estuários (advindos de centros urbanos) e aqueles oriundos do descarte direto no mar por embarcações de turismo e de comércio. Esse tipo de impacto é potencialmente a causa de morte de centenas de indivíduos/ano de tartarugas marinhas. A ingestão, com subsequente obstrução do trato digestivo, desses materiais é a principal interação negativa observada. Buscando se há concordância entre o tipo de lixo aportado nas praias, áreas de alimentação e conteúdos gastrointestinais das tartarugas marinhas, o presente estudo visou quantificar e tipificar os resíduos sólidos encontrados nas praias, no mar e nos tratos gastrointestinais de tartarugas marinhas. Para tal foram realizadas coletas no mar e seis praias no estado da Paraíba e analisados 26 conteúdos gastrointestinais de tartarugas marinhas (de um total de 200 coletados), que apresentaram resíduos antrópicos. As coletas no mar foram feitas no Parque Estadual da Ilha de Areia Vermelha (PEMAV) e Picãozinho. Os resíduos sólidos presentes em conteúdos estomacais foram aqueles provenientes das coletas sistemáticas realizadas pela equipe da ONG-Guajiru de 2009 a 2012. Neste estudo foi coletado um total de 20.700 itens sendo 68,904 kg de lixo coletado - 13.210 itens nas praias, 8 nas áreas de alimentação e 7.482 nas tartarugas marinhas. O plástico correspondeu a 60,85% do total dos itens coletados representando 25,17% do peso total, seguido por matéria orgânica 10,13% e nylon com 9,85%. As praias com maior quantidade de lixo foram as com >50 mil habitantes com 6.080 itens (29,37%) do lixo total coletado e o conteúdo gastrointestinal das tartarugas marinhas apresentaram a maior quantidade de lixo do estudo com 7.482 itens (36,14%). De todas as tartarugas coletadas, 16 apresentavam CCC >35 cm e possuíam 3.649 itens plásticos em seu trato gastrointestinal, sendo 3.220 plásticos flexíveis e 429 plásticos rígidos. Esses dados podem ser utilizados para aplicações de planos de gerenciamento costeiro integrado, a fim de banir a presença de lixo no mar e a poluição dos oceanos. Os resultados demonstram que o lixo nas áreas de alimentação são de origem antrópica direta, devido aos visitantes, o lixo das praias apresentam sua origem da drenagem continental, descarte direto no mar por embarcações de turismo e de comércio e principalmente da população local e turistas, e que o lixo encontrado nas tartarugas não são apenas vindos do continente, mas um resultado de todos os tipos de aporte desses matérias no mar.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-10T15:15:37Z No. of bitstreams: 1 sarahdasilvamendes.pdf: 575630 bytes, checksum: ad12b2b2db4042c4e06195378407b834 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T15:09:28Z (GMT) No. of bitstreams: 1 sarahdasilvamendes.pdf: 575630 bytes, checksum: ad12b2b2db4042c4e06195378407b834 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T15:09:44Z (GMT) No. of bitstreams: 1 sarahdasilvamendes.pdf: 575630 bytes, checksum: ad12b2b2db4042c4e06195378407b834 (MD5) / Made available in DSpace on 2017-05-17T15:09:44Z (GMT). No. of bitstreams: 1 sarahdasilvamendes.pdf: 575630 bytes, checksum: ad12b2b2db4042c4e06195378407b834 (MD5) Previous issue date: 2013-02-26 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os filhotes e juvenis de quelônios não apresentam anatomicamente características sexuais secundárias visíveis, não sendo possível diferenciar o sexo através da observação da carapaça. Vários autores defendem a análise histológica como a melhor técnica para se realizar a sexagem de filhotes da espécie Caretta caretta. O objetivo do presente trabalho foi realizar a identificação sexual de filhotes de C. caretta através da morfometria geométrica e da histomorfologia. Foram utilizados 73 filhotes natimortos, coletados em diversos ninhos ao longo da Praia da Guanabara, Anchieta, Espírito Santo, Brasil. Para a análise morfométrica, cada animal teve a carapaça fotografada. Posicionado em decúbito dorsal foram retirados o plastrão, intestino grosso, fígado e bexiga para permitir a visualização das gônadas e rins, que após fotografados foram armazenados em formalina 10% tamponada. Foram utilizados os softwares TPSUtil, TPSDig2, CoordGen, PCAGen e CVAGen para as análises morfométricas. O processamento do material seguiu as etapas convencionais da técnica histológica. Com base na análise de componentes principais (PCA), PC1 explicou 19,83% da variação na carapaça dos filhotes, enquanto PC2 explicou 14,71%. Análise de variáveis canônicas revelou que há uma tendência de dimorfismo sexual entre os filhotes, através da carapaça e que essa pode estar relacionada com o sexo dos exemplares. As gônadas estavam localizadas próximas ao hilo renal, com formato filiforme. Nos ovários foi possível observar um córtex com epitélio cúbico e bem desenvolvido, associado a uma medula desorganizada e rica em matriz intersticial. O córtex dos testículos era composto por uma fina camada de epitélio pavimentoso simples, uma medula muito bem desenvolvida e com pouca matriz intersticial, observando-se vários túbulos seminíferos, nitidamente distinguíveis. Trabalhos realizados com filhotes de tartaruga cabeçuda e outras espécies de quelônios, utilizando a morfometria geométrica, também demonstraram haver diferenças na carapaça que distinguem o sexo de filhotes recém nascidos. As características histológicas identificadas foram semelhantes às encontradas por outros autores. Outros trabalhos defendem que a análise macroscópica é suficiente para identificar o sexo de filhotes de tartarugas, o que foi demonstrado efetivamente para Dermochelys coriacea e Chelonia mydas, mas não foi efetivo para C. caretta. A morfometria geométrica se mostrou uma ferramenta útil, tendo a histomorfometria das gônadas de filhotes de C. caretta, confirmado o dimorfismo sexual apontado pela morfometria geométrica. / The hatchlings and juvenile turtles have not anatomically visible secondary sex characteristics, it is not possible to differentiate sex by viewing the carapace. Several authors advocate histological analysis as the best technique for performing sexing chicks of the species Caretta caretta. The aim of this study was to identify sex of baby C. caretta by geometric morphometrics and histomorphology. 73 stillborn pups were used, collected in different nests along the Guanabara´s, Beach Anchieta, Espírito Santo, Brazil. For morphometric analysis each animal had photographed the shell. Were positioned supine removed the plastron, large intestine, liver and bladder to allow visualization of the kidneys and gonads, photographed after they were stored in 10% buffered formalin. We used the software TPSUtil, TPSDig2, CoordGen, PCAGen CVAGen for morphometrics analysis. The histological analysis followed the steps of conventional histological technique. Based on principal component analysis (PCA), PC1 explained 19.83% of the variation in the carapace of the puppies, while PC2 explained 14.71%. Canonical analysis revealed that there is a trend of sexual dimorphism between the pups through the carapace and that this may be related to the sex of the specimens. The gonads were located near the renal hilum, with threadlike format. Ovarian cortex was possible to observe a cuboidal epithelium with well developed, associated with a disorganized medulla and interstitial-rich matrix. The cortex of the testes was composed of a thin layer of simple squamous epithelium, a very well-developed marrow and low interstitial matrix, observing several seminiferous tubules clearly distinguishable. The macroscopic analysis of gonads alone does not allow the differentiation of the sexes, thus corroborating other work done with this species and other sea turtles. Work done with baby loggerhead turtles and other species also showed significant differences in the carapace that distinguish the sex of newly hatched chicks. The histological features were similar to those identified by other authors, some argue that the macroscopic analysis is sufficient to identify the sex of pups, which has been shown to effectively Dermochelys coriacea and Chelonia mydas, but was not effective in C. caretta. Hormonal measurements were also satisfactory to sex in order to cubs C. mydas, but authors disagree on this method to other species. The geometric morphometrics has the potential to Histology is an excellent tool for choosing to sex most used so far.

The current accepted methods for assessing the effect of water temperatures on sea turtle nesting, utilizes sea surface temperatures (SST). Since Loggerhead sea turtles spend the majority of their time near the ocean floor, often below a thermocline, bottom temperature analysis should be a better estimate of actual temperature experienced by the sea turtles, therefore, correlating better to nesting events. Thermograph data sensors were placed along three reef tracts that run parallel to Broward County, Florida’s coastline, to collect bottom seawater temperatures from the year 2004 through 2006. Detrended average daily bottom temperatures were compared to detrended Loggerhead sea turtle nest counts collected by daily beach monitoring throughout the county. The comparisons confirmed that during the years 2004 and 2006, up to 29.6% of the fluctuations in sea turtle nesting can be associated to the short-term changes in bottom water temperature. r2-values of 0.2963 and 0.2948 were determined along the Broward County coastline, with p-values<0.001. No significant correlations were found in the year 2005 when bottom water temperature variations were smaller than in the other years. This evaluation shows that Loggerhead sea turtle nesting counts can be highly correlated to bottom seawater temperatures, in Broward County, Florida. Better understanding of a location’s temperature fluctuations can lead to a better management and conservation plan for the associated species and habitat.

Le climat affecte entre autre la phénologie, l’aire de distribution, le comportement et la physiologie des espèces. Le changement climatique a donc des répercussions sur chacun de ces facteurs. L’augmentation globale des températures prévue d’ici 2100 pourrait profondément modifier la biodiversité de l’échelle des espèces jusqu’à celle des écosystèmes. Les ectothermes, et en particulier les reptiles ovipares à détermination du sexe sensible à la température, font partie des organismes susceptibles d’être les plus vulnérables au réchauffement du climat puisque quasiment tous leurs traits d’histoire de vie dépendent de la température. L’origine et le maintien de ce mécanisme de détermination du sexe, pouvant conduire à un sex ratio fortement biaisé à l’échelle d’une population, reste une énigme pour les écologues. Parmi les nombreuses questions soulevées par la présence de ce mécanisme de détermination du sexe, la signification adaptative, s’il y en a une, de ce mécanisme est cruciale.Ce mécanisme de détermination du sexe rend-il les espèces plus vulnérables dans le contexte actuel du changement du climat ? Plusieurs hypothèses évolutives ont été proposées et des modèles de dynamique des populations sont disponibles pour répondre à ces questions. Cependant, prédire le sex ratio primaire en conditions naturelles, c’est-à-dire le sex ratio des nouveaux nés, reste un défi majeur à l’heure actuel. Ce manuscrit vise à apporter de nouveaux outils méthodologiques afin de correctement prédire le sex ratio d’une ponte en fonction de la température ressentie par les embryons au cours de l’incubation. Les tortues marines,quasiment toutes menacées, sont des espèces migratrices présentant toute ce mécanisme de détermination du sexe.Chez ces espèces, la phénologie des pontes est aussi sensible à la température du milieu. Ce type de plasticité phénotypique est probablement la stratégie la plus efficace pour pallier à un changement rapide du climat. Ce manuscrit apporte quelques éléments de réponse quant au potentiel adaptatif des tortues marines face au réchauffement climatique avec l’exemple de plusieurs populations de tortues Caouanne (Caretta caretta). / Climate affects, among other things, species’phenology, distribution range, behavior and physiology.Climate change thus impacts each of these factors. Global warming expected by 2100 might profoundly modify biodiversity from species to ecosystems. Ectotherms, and in particular oviparous reptiles with temperature dependent sex determination, are thought to be among the most vulnerable in the face of global warming because virtually all their life history traits depend on temperature.The origin and the persistence of temperature-dependent sex determination, which could lead to heavily biased population sex ratios, is still an enigma for ecologists. Among numerous issues related to this sex determining mechanism, understanding its adaptive significance, if there is one, is crucial. At another level, does this sex determining mechanism make species more vulnerable in the context of contemporary climate change ? Several evolutionary hypotheses have been proposed and population dynamic models are available to address these issues. However, predicting primary sex ratio, i.e., the sex ratio of hatchlings, in natural conditions currently remainsa challenge. This manuscript aims to bring new methodological tools to properly predict sex ratio of aclutch depending on temperature experienced by embryosthroughout incubation. Marine turtles, almost all being threatened, are migratory species that all exhibit this sex determining mechanism. For those species, nesting phenology is also sensitive to environmental temperature.This type of phenotypic plasticity is probably the most efficient strategy to keep up with rapid climate change.This manuscript provides some elements for understanding the adaptive potential of sea turtles in the face of global warming with the example of several).

<p>Green turtles (<em>Chelonia mydas</em>) perform ocean-crossing migrations, maintain healthy marine ecosystems, generate income through tourism, and are endangered and declining globally. For these reasons, among others, this species has been a focus of numerous research programs worldwide for almost a century. Most of these sea turtle research programs require some form of animal handling to collect the required data (e.g., tagging information or the collection of biological samples). However, this can cause stress, especially for wild animals, and that raises ethical issues. Here, I describe novel methods for assessing and mitigating the effects of handling stress on green turtles. Specifically: (1) I used a combination of animal-borne cameras and drone footage to determine how handling stress altered the post-release behavior of green turtles and (2) I used a photo-ID software to determine whether flipper scales can provide more accurate identifications than the more conventionally used facial scale patterns. </p> <p><br></p> <p>I found that turtles spent more time swimming and had shortened dive intervals in the first 30 mins after capture and attachment of a camera than in the hours that follow. Instances of socializing, foraging and resting increased over the 3-3.5 h after release. Animals recorded by drone and not captured were less likely to rest, which suggests this behavior may be a recovery response to handling and/or stress. The same animals were also more likely to socialize. When determining the accuracy of flipper or facial images for photo-ID, I found that head scales provided correct identifications 80% of the time, whereas the flipper provided correct identifications 100% of the time. This implies that researchers could use the flipper instead of more invasive tagging techniques, such as metal flipper tags or using lights to photograph the face for photo-ID, which can induce stress.</p>

Sea level rise (SLR) is posing a great risk of flooding and inundation to coastal areas in Florida. Some coastal nesting species, including sea turtle species, have experienced diminished habitat from SLR. In an effort to assess the economic and ecosystem service loss to coastal areas with respect to sea turtles Contingent Valuation Method (CVM) and Habitat Equivalency Analysis (HEA) were used. The CVM was used to measure the economic impacts of SLR on sea turtles. Open-ended and dichotomous choice CVM was used to obtain the willingness to pay (WTP) values of Florida residents to implement certain mitigation strategies which would protect Florida’s east coast sea turtle nesting areas. The problem of sample selection bias was reduced by surveying residents of two cities that would potentially have varying interest in coastal conservation due to their relative distance from the coast. The hypothetical WTP of Florida households to implement policies designed to protect sea turtle habitat from development encroachment was estimated to be between $21 and $29 per year for a maximum of five years. Characteristics of respondents were found to have statistically significant impacts on their WTP. Findings include a negative correlation between the age of a respondent and the probability of an individual willing to pay the hypothetical WTP amount. Counter intuitively, it was found that WTP of an individual was not dependent on prior knowledge of the effects of SLR on sea turtle habitat. As the level of this awareness increased, the probability to pay the hypothetical WTP value decreased. The greatest indicators of whether or not an individual was willing to pay to protect sea turtle habitat were the respondents’ perception regarding the importance of sea turtle population health to the ecosystem, and their confidence in the conservation methods used. iii Concepts of Habitat Equivalency Analysis were used in order to determine the ecosystem service lost due to SLR. The study area of Archie Carr National Wildlife Refuge (ACNWR) has a continually increasing sea turtle population due to various conservation efforts. However, how the inundation of the coastal area will injure this habitat was assessed, and if mitigation strategies to compensate for the loss are necessary. The carrying capacity (CC) of the refuge was chosen as the metric of the ecosystem service. Using the estimated area of ACNWR and the approximate area needed by a sea turtle to nest, the theoretical number of sea turtle nests possible on the refuge was calculated. This value was then projected to the year 2100 using the sea level rise scenarios provided by IPCC (2007) and NRC (2010). In order to quantify the injury caused by the decrease in the refuge’s CC, the number of sea turtle nests on the refuge was projected to the year 2100 using the data obtained over the past 30 years. The analysis concludes a potential loss of service to be experienced as early as 2060’s due to the carrying capacity of the refuge diminishing with the loss of the habitat due to the increase in the mean sea level.

Changes in abundance of interactive species can have cascading, community-wide effects (Soule et al. 2003). Raccoons (Procyon lotor) prey on a competitor for marine turtle eggs, the Atlantic ghost crab (Ocypode quadrata). Conservation of marine turtles often includes managing raccoons-the most obvious egg predator-which may have broader ecological effects, and unknown effects on egg predation. Neither the relationship between raccoons and ghost crab density nor the effects of ghost crab density on egg predation are well understood. I studied raccoon-ghost crab interactions and the effects of environmental variation on their activity during the 2007 marine turtle nesting season on Canaveral National Seashore, FL. My goal was to model predator activity and identify efficient management strategies to reduce egg predation. Raccoon activity increased with increasing habitat diversity and edge of the dominant cover type, coastal strand. Raccoon activity increased locally and became less variable near segments of beach accessed for human recreation, but activity was greater on undeveloped beach, where habitat diversity and edge were greater. Ghost crab density and size were primarily affected by sand characteristics and recreation but decreased with increasing raccoon activity in June, which may have contributed to sustained declines in ghost crab density. Hatching success of marine turtles decreased with increasing ghost crab egg predation, suggesting ghost crabs are an important cause of egg mortality and not merely scavengers on unhatched eggs. Egg predation by ghost crabs was unrelated to ghost crab density or size, likely a result of monitoring limitations, but raccoon activity increased with increasing egg predation by ghost crabs, supporting previous research and experimental evidence suggesting ghost crabs can facilitate secondary nest predation by raccoons. This indirect interaction has strong implications for marine turtle conservation, because its strength may increase with increasing ghost crab density, potentially negating the effects of raccoon removal.

The genetic structure of juvenile green turtles (Chelonia mydas) foraging on the east coast of central Florida is not well understood, nor has it been examined over time. In the last three decades, the dramatic increase in the number of green sea turtle nests in Florida, in association with other population parameters, has led to this species being down-listed under the Endangered Species Act from “endangered” to “threatened” in the northwest Atlantic. However, it was unclear if the exponential growth in Florida nest numbers had any influence on the genetic structure of juveniles in nearby foraging aggregations. To understand this potential impact mixed-stock analysis was conducted using mitochondrial DNA fragments that were over 800 base pairs long on samples taken from juveniles captured from 2002-2005 and 2016-2018 in the central Indian River Lagoon and Trident Submarine Basin in Port Canaveral. Results indicate the sampled foraging sites are genetically distinct habitats. In both sites, recruitment from Florida nesting beaches remained low despite increases in nesting while contributions from rookeries in Costa Rica and Mexico dominated both foraging aggregations across time. Haplotype diversity and nucleotide diversity decreased at both foraging sites over time. The foraging sites shared the two most frequently occurring haplotypes, but also had haplotypes that were unique to the site or sample period. Our results highlight the need for broader sampling of rookeries and foraging aggregations to understand the impacts of nesting increases in one rookery on juvenile diversity. Future studies should include all life stages of green turtles to enhance understanding of both the census population and effective population to better inform conservation policies necessary for a continued recovery.

The U.S. pelagic longline fishery catches 98% of domestic swordfish landings but is also one of the three fisheries most affecting federally protected sea turtles (Crowder and Myers 2001, Witherington et al 2009). Bycatch by fisheries is considered the main anthropogenic threat to sea turtles (NRC 1990). Accurate and precise bycatch estimates are imperative for sea turtle conservation and appropriate fishery management. However, estimation is complicated by only 8% observer coverage of fishing and data that are hierarchical in structure (i.e., multiple sets per trip), zero-heavy (i.e., bycatch is rare), and often overdispersed (i.e., larger variance than expected). Therefore, I evaluated two predominant bycatch estimation methods, the delta-lognormal method and generalized linear models, and investigated improvements in uncertainty incorporation. I constructed a simulation model to evaluate bycatch estimation at two spatial scales under ten spatial models of sea turtle, fishing set, and observer distributions. Results indicated that distributing observers relative to fishing effort and using the delta-lognormal-strata method was most appropriate. The delta-lognormal-strata 95% confidence interval (CI) was wider than statistically appropriate. The delta-lognormal-all sets pooled 95% CI was narrower but simulated bycatch was above the CI too frequently. Thus, I developed a bycatch estimate risk distribution to incorporate uncertainty in bycatch estimates. It gives managers access to the entire distribution of bycatch estimates and their choice of any risk level. Results support the management agency's observer distribution and estimation method but suggest a new procedure to incorporate uncertainty. This study is also informative for many similar datasets. / Master of Science