Fibropapilomatose (FP) é uma doença caracterizada por múltiplas massas de tumores cutâneos variando de 0,1 a mais de 30 cm em diâmetro. Afeta primariamente tartarugas-verdes (Chelonia mydas), mas também outras espécies de tartarugas marinhas ao redor do mundo. O objetivo deste estudo é, através de dados já sistematicamente coletados pelo Programa Brasileiro de Proteção, Pesquisa e manejo das Tartarugas Marinhas - Projeto TAMAR-IBAMA, caracterizar, no tempo e no espaço, a ocorrência desta doença em tartarugas marinhas na costa brasileira, entre os anos de 2000 a 2005. As tartarugas encontradas, vivas ou mortas, foram identificadas, medidas e examinadas quanto à presença ou ausência de tumores. Nesse período foram examinadas 10.170 tartarugas marinhas, sendo 1.243 tartarugas-de-pente, (Eretmochelys imbricata), das quais 2 apresentaram tumores; entre as 250 tartarugas- cabeçudas, (Caretta caretta), 5 apresentaram tumores; entre as 288 tartarugas-oliva (Lepidochelys olivacea), 3 apresentaram tumores; nenhuma das 30 tartarugas-gigantes, (Dermochelys coriacea) examinadas tinham tumores. A maior parte dos registros (82,20 %; 8.359 de 10.170) correspondeu a tartarugas-verdes (Chelonia mydas), das quais 1.288 apresentavam tumores. Foram coletadas amostras de tumores de 80 tartarugas para análise histopatológica; todas foram positivas para fibropapilomatose. A média da prevalência nacional geral para Chelonia mydas foi de 15.41%; apenas nas áreas costeiras a doença foi verificada. Nenhuma ocorrência foi registrada nas ilhas oceânicas do Atol das Rocas e do Arquipélago de Fernando de Noronha. Os resultados das freqüências de tumores por estado foram: Bahia, 15,81% (211/1335); Ceará, 36,94% (181/490); Espírito Santo, 27,43% (469/1710); Pernambuco-Arquipélago de Fernando de Noronha, 0,00% (0/501); Rio de Janeiro, 5,96% (9/151); Rio Grande do Norte-região costeira, 31,43% (33/105); Rio Grande do Norte-Atol das Rocas, 0,00% (0/486); Sergipe, 18,46% (12/65); São Paulo, 10,73 % (371/3456). Os animais afetados variaram de juvenis com comprimento curvilíneo de carapaça (CCC) mínimo de 30,0 cm, subadultos a adultos com máximo de 112 cm. A prevalência de tumores associado a fibropapilomatose aumentou com o CCC até 80,0 cm e decresceu abruptamente. A caracterização da doença foi realizada com um grupo de 202 tartarugas verdes afetadas em uma agregação no Estado do Espírito Santo. Nesse grupo, o número de tumores variou de 1 a 179 tumores em um único animal, tendo como média 21 tumores por tartaruga afetada. 72,5 % dos tumores estavam localizados na região anterior corpórea do animal, 25,2% na região posterior e 2,3% na carapaça e plastrão. Nenhuma tartaruga apresentou tumores na cavidade oral. Para análise de escore de tumor em tartarugas afetadas com FP, o escore de tumor 1 e 2 foi predominante, com 40,61% (80 de 197) e 51,27% (101 de 197) respectivamente. Apenas 8,12% (16 de 197) das tartarugas tiveram escore de tumor 3. / Fibropapilomatosis (FP) is a disease characterized by multiple masses of cutaneous tumors varying from 0,1 to more than 30 cm in diameter. It has affected primarily green turtles (Chelonia mydas), but also other species of sea turtles around the world. The aim of this study is, through the data already systematically collected by the Brazilian Sea Turtle Protection, Research and Management Program - Projeto TAMAR - IBAMA to characterize the occurrence of this disease in marine turtles along the Brazilian coast to within time and space, from 2000 to 2005. Turtles found alive or dead were identified as for the species, measured and examined as for the presence or absence of tumors. 10.170 sea turtles were examined: 1.243 of them were Hawksbills (Eretmochelys imbricata), two of which showed tumors; five of the 250 loggerhead turtles (Caretta caretta) and three of 288 olive ridley\'s turtles (Lepidochelys olivacea), showed tumors; none of the 30 leatherback (Dermochelys coriacea) carried tumors. Mostly of the records, (82,20%; 8.359/10170) corresponded to green turtles (Chelonia mydas), 1.288 of which had tumors. Samples of tumors were collected from 80 turtles for histopathologycal analysis; all examined samples were positive for fibropapillomatosis. The average nationwide tumor prevalence in Chelonia mydas was 15.41%; the disease was detected only in coastal areas: no occurrence was recorded for the oceanic islands of Atol das Rocas and Fernando de Noronha Archipelago. The tumor frequencies by state were: Bahia, 15,81% (211/1335); Ceará, 36,94% (181/490); Espírito Santo, 27,43% (469/1710); Pernambuco - Archipelago of Fernando de Noronha, 0,00% (0/501); Rio de Janeiro, 5,96% (9/151); Rio Grande do Norte- coastal area, 31,43% (33/105); Rio Grande do Norte - Atol das Rocas, 0,00% (0/486); Sergipe, 18,46% (12/65); São Paulo, 10,73% (371/3456). The affected animals varied from juvenile, with minimum curved carapace length (CCC) 30,0 cm to sub-adults, adults with a maximum 112 cm. The prevalence of tumours associated to fibropapillomatosis increased with CCC up to 80,0 cm and then decreased abruptly. The number of tumors in 202 affected green turtles from an aggregation in the state of Espírito Santo varied from 1 to 179 tumors in a single animal, with an average of 21 tumors per affected turtle. 72,5% of tumors were located in the anterior half of the animal\'s bodies, 25,2% in the posterior area, 2,3% on the shell and plastron. No turtle had tumors in the oral cavity. A predominance of turtles was registered with tumors score 1, 40,61% (80 of 197) and score 2, 51,27% (101/197). Only 8,12% (16/197) of the turtles that had score 3. For analysis of tumor score in affected turtles with FP, the tumors score 1 and 2 was predominant, with (40,61%; 80 of 197) and (51,27%; 101/197) respectively. Only 8,12 % (16/197) of the turtles attained tumors score 3.

Fibropapilomatose (FP) é uma doença caracterizada por múltiplas massas de tumores cutâneos variando de 0,1 a mais de 30 cm em diâmetro. Afeta primariamente tartarugas-verdes (Chelonia mydas), mas também outras espécies de tartarugas marinhas ao redor do mundo. O objetivo deste estudo é, através de dados já sistematicamente coletados pelo Programa Brasileiro de Proteção, Pesquisa e manejo das Tartarugas Marinhas - Projeto TAMAR-IBAMA, caracterizar, no tempo e no espaço, a ocorrência desta doença em tartarugas marinhas na costa brasileira, entre os anos de 2000 a 2005. As tartarugas encontradas, vivas ou mortas, foram identificadas, medidas e examinadas quanto à presença ou ausência de tumores. Nesse período foram examinadas 10.170 tartarugas marinhas, sendo 1.243 tartarugas-de-pente, (Eretmochelys imbricata), das quais 2 apresentaram tumores; entre as 250 tartarugas- cabeçudas, (Caretta caretta), 5 apresentaram tumores; entre as 288 tartarugas-oliva (Lepidochelys olivacea), 3 apresentaram tumores; nenhuma das 30 tartarugas-gigantes, (Dermochelys coriacea) examinadas tinham tumores. A maior parte dos registros (82,20 %; 8.359 de 10.170) correspondeu a tartarugas-verdes (Chelonia mydas), das quais 1.288 apresentavam tumores. Foram coletadas amostras de tumores de 80 tartarugas para análise histopatológica; todas foram positivas para fibropapilomatose. A média da prevalência nacional geral para Chelonia mydas foi de 15.41%; apenas nas áreas costeiras a doença foi verificada. Nenhuma ocorrência foi registrada nas ilhas oceânicas do Atol das Rocas e do Arquipélago de Fernando de Noronha. Os resultados das freqüências de tumores por estado foram: Bahia, 15,81% (211/1335); Ceará, 36,94% (181/490); Espírito Santo, 27,43% (469/1710); Pernambuco-Arquipélago de Fernando de Noronha, 0,00% (0/501); Rio de Janeiro, 5,96% (9/151); Rio Grande do Norte-região costeira, 31,43% (33/105); Rio Grande do Norte-Atol das Rocas, 0,00% (0/486); Sergipe, 18,46% (12/65); São Paulo, 10,73 % (371/3456). Os animais afetados variaram de juvenis com comprimento curvilíneo de carapaça (CCC) mínimo de 30,0 cm, subadultos a adultos com máximo de 112 cm. A prevalência de tumores associado a fibropapilomatose aumentou com o CCC até 80,0 cm e decresceu abruptamente. A caracterização da doença foi realizada com um grupo de 202 tartarugas verdes afetadas em uma agregação no Estado do Espírito Santo. Nesse grupo, o número de tumores variou de 1 a 179 tumores em um único animal, tendo como média 21 tumores por tartaruga afetada. 72,5 % dos tumores estavam localizados na região anterior corpórea do animal, 25,2% na região posterior e 2,3% na carapaça e plastrão. Nenhuma tartaruga apresentou tumores na cavidade oral. Para análise de escore de tumor em tartarugas afetadas com FP, o escore de tumor 1 e 2 foi predominante, com 40,61% (80 de 197) e 51,27% (101 de 197) respectivamente. Apenas 8,12% (16 de 197) das tartarugas tiveram escore de tumor 3. / Fibropapilomatosis (FP) is a disease characterized by multiple masses of cutaneous tumors varying from 0,1 to more than 30 cm in diameter. It has affected primarily green turtles (Chelonia mydas), but also other species of sea turtles around the world. The aim of this study is, through the data already systematically collected by the Brazilian Sea Turtle Protection, Research and Management Program - Projeto TAMAR - IBAMA to characterize the occurrence of this disease in marine turtles along the Brazilian coast to within time and space, from 2000 to 2005. Turtles found alive or dead were identified as for the species, measured and examined as for the presence or absence of tumors. 10.170 sea turtles were examined: 1.243 of them were Hawksbills (Eretmochelys imbricata), two of which showed tumors; five of the 250 loggerhead turtles (Caretta caretta) and three of 288 olive ridley\'s turtles (Lepidochelys olivacea), showed tumors; none of the 30 leatherback (Dermochelys coriacea) carried tumors. Mostly of the records, (82,20%; 8.359/10170) corresponded to green turtles (Chelonia mydas), 1.288 of which had tumors. Samples of tumors were collected from 80 turtles for histopathologycal analysis; all examined samples were positive for fibropapillomatosis. The average nationwide tumor prevalence in Chelonia mydas was 15.41%; the disease was detected only in coastal areas: no occurrence was recorded for the oceanic islands of Atol das Rocas and Fernando de Noronha Archipelago. The tumor frequencies by state were: Bahia, 15,81% (211/1335); Ceará, 36,94% (181/490); Espírito Santo, 27,43% (469/1710); Pernambuco - Archipelago of Fernando de Noronha, 0,00% (0/501); Rio de Janeiro, 5,96% (9/151); Rio Grande do Norte- coastal area, 31,43% (33/105); Rio Grande do Norte - Atol das Rocas, 0,00% (0/486); Sergipe, 18,46% (12/65); São Paulo, 10,73% (371/3456). The affected animals varied from juvenile, with minimum curved carapace length (CCC) 30,0 cm to sub-adults, adults with a maximum 112 cm. The prevalence of tumours associated to fibropapillomatosis increased with CCC up to 80,0 cm and then decreased abruptly. The number of tumors in 202 affected green turtles from an aggregation in the state of Espírito Santo varied from 1 to 179 tumors in a single animal, with an average of 21 tumors per affected turtle. 72,5% of tumors were located in the anterior half of the animal\'s bodies, 25,2% in the posterior area, 2,3% on the shell and plastron. No turtle had tumors in the oral cavity. A predominance of turtles was registered with tumors score 1, 40,61% (80 of 197) and score 2, 51,27% (101/197). Only 8,12% (16/197) of the turtles that had score 3. For analysis of tumor score in affected turtles with FP, the tumors score 1 and 2 was predominant, with (40,61%; 80 of 197) and (51,27%; 101/197) respectively. Only 8,12 % (16/197) of the turtles attained tumors score 3.

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.

Coastal habitats are highly dynamic and vulnerable to landscape-level disturbances such as storms and restoration projects. Along the east coast of Florida these areas are particularly valuable as they provide significant nesting habitat for two sea turtle species, the threatened loggerhead (Caretta caretta) and the endangered green turtle (Chelonia mydas). This coast was heavily impacted by three major hurricanes in 2004 and in some areas by large restoration projects in 2005. Recent remote sensing methods allow for broad evaluation of the shoreline and thus the ability to assess sea turtle nesting habitat at a landscape scale. I collected nesting data for southern Brevard County, Florida from 1989 – 2005 and for Canaveral National Seashore, Florida from 1995 – 2005. I used LiDAR (Light Detection and Ranging) and IfSAR (Interferometric Synthetic Aperture Radar) remote sensing to map sea turtle nesting habitat in both areas following the 2004 hurricanes and any subsequent restoration. Canaveral National Seashore underwent no restoration while southern Brevard County received extensive restoration. Topographic variables (e.g., total sand volume, width, and slope) derived from the remote sensing data were compared across three time periods (pre-hurricane, posthurricane, and recovery period) and I compared nesting success data from 2004 to 2005. I built regression models for 2004 and 2005 to determine which topographic features influenced loggerhead and green turtle nesting the most. Green turtle nesting success declined from 2004 to 2005 only in highly restored areas while loggerhead nesting sucess declined throughout. Hurricanes caused a reduction in most of the topographic variables and restoration predominantly impacted aspects of the beach profile (e.g. slope and width). Loggerheads responded to profile characteristics (e.g. upper and lower iii beach slopes) though green turtles showed no consistent response to topography. The results indicate that both loggerheads and green turtles are sensitive to beach restoration, although loggerhead nesting is more influenced by beach morphology and green turtle nesting may be influenced more by other dune features such as vegetation cover.

Artificial beach nourishment, the most common method to mitigate coastal erosion in the United States, is also considered the most ecologically friendly alternative for shoreline stabilization. However, this habitat alteration has the potential to impact nesting marine turtles and developing hatchlings. The first objective of this study was to determine how nourishing beaches with two different design templates affects loggerhead (Caretta caretta) and green turtle (Chelonia mydas) nesting success, the ratio of nests to the total number of nests and non-nesting emergences, and reproductive success, the ratio of hatched and emerged hatchlings to the total number of eggs deposited. Two types of restoration designs exist along the southern Brevard County, FL coastline, which supports some of the highest density loggerhead and green turtle nesting worldwide. Since 2005, approximately 35 kilometers of beach have undergone 1) fullscale restoration (typically called nourishment), where sand was added above and below the mean high tide line (2005, 2010) or 2) dune restoration, where sand was placed on the dune (2005, 2006, 2008, 2009). To quantify the effects of these restoration types, we used a Before-After-ControlImpact-Paired Series (BACIPS) model, which tests for significance between the difference in nesting success rates at the impact (engineered) and control sites (natural beach) before and after restoration ( ). For loggerheads, there was a significant difference in after dune restoration during the years of construction (2005, 2006, 2008, and 2009; p

Marine turtles exhibit strong fidelity to their nesting beaches, making the conservation of nesting beaches important for ensuring successful sea turtle populations. Conservation of these nesting beaches involves understanding how species interact with the environment and each other, and understanding how environmental change and population growth can affect the suitability of the nesting habitat. The Archie Carr National Wildlife Refuge (ACNWR) is unusual in its high density of sea turtle nesting by two species: green (Chelonia mydas) and loggerhead (Caretta caretta) turtles. The ACNWR in Melbourne Beach, Florida was established in 1991 due to the high density of loggerhead nesting, but in the time since it was established there has been a significant increase in green turtle nesting, from fewer than 50 nests in 1982 to over 15,000 in 2017. With such a high density of these two species in one relatively small area (21 kilometers of beach), the two species may compete for space. This is especially true for green turtles, which disturb large amounts of sand during their nesting process; in 2017, we observed 338 loggerhead clutches disturbed by nesting females during nesting surveys, nearly all of which were disturbed by green turtles. Using observed spatial and temporal nesting patterns for both green turtles and loggerheads on the ACNWR, I examined the effects these species may have on each other's nests now and in the future. Additionally, green turtles and loggerheads nest in different densities along the length of the ACNWR, with green turtles more concentrated in the southern portions of the Refuge. Finally, green turtle nesting begins and peaks approximately one month later on the ACNWR than loggerhead nesting. For each of these metrics, there is both considerable overlap and distinct separation between the two species. By using these metrics in a modeling approach, I estimated the probability of nest disturbance by a subsequently nesting female, ranging from 0 to 0.105, and how these probabilities are predicted to change over time with a growing green turtle population. Evaluating the carrying capacity of this beach is important in the context of habitat disturbance, including climate change and an increase in storm frequency, and informing adaptive management strategies for effective conservation.

Causes of morbidity and mortality were investigated for 108 green turtles (Chelonia mydas) stranded in south-east Queensland between 1990 and 1996. This study was undertaken as part of a broader carcass salvage program for south Queensland, and within the context of a population study of C. mydas in the Moreton Bay feeding ground. Accurate pathological characterisation of disease in C. mydas was achieved by detailed necropsy and histological examination. Varied inflammatory responses and degenerative changes were observed in stranded C. mydas. Supportive disciplines of microbiology, parasitology, and clinical chemistry were used to elucidate aetiology and pathogenesis of selected conditions. Heavy metal and pesticide levels were assessed in a sub-sample of turtles. Direct anthropogenic causes (including trauma, foreign body ingestion and drowning) accounted for 34% of mortalities of C. mydas in this study. The majority of the trauma cases were turtles with skull fractures resulting from blunt impacts. The remainder had boat propeller injuries, or miscellaneous trauma. Almost half of the turtles with lethal boat propeller damage had evidence of pre-existing disease which may well have predisposed them to boat strike, emphasising the importance of full necropsy examination, even when the cause of death appears obvious. Fishing line was the only ingested foreign body consistently implicated in the production of fatal intestinal obstruction. Marine turtle fibropapillomatosis, a panzootic viral disease which is considered to involve some indirect anthropogenic factors, accounted for 7% of mortalities. The findings in this study were consistent with much of the previously described pathology of this condition. Naturally-occurring diseases (for which human influences are unknown) accounted for the remaining 59% of strandings. Coccidiosis, caused by Caryospora cheloniae, was recorded for the first time in wild C. mydas. It occurred both as an epizootic (in 1991) and as sporadic cases. A variety of manifestations, including disseminated and enteric forms, were recognised. Infection with a Cryptosporidium-like protozoan appeared to occur concurrently with coccidiosis in one turtle in this study. Attempts to establish experimental coccidial infections in hatchling C. mydas were unsuccessful. Infections with cardiovascular (spirorchid) flukes were almost universal in stranded C. mydas in this study. They ranged from mild, incidental findings (such as occasional fluke vii egg granulomas evident microscopically in otherwise normal tissues) to a variety of severe changes, including thrombosis, which were likely to have produced morbidity. The present study clarified the range of cardiovascular lesions associated with spirorchidiasis, including the sequence of thrombus resolution and exteriorisation from vessels. In some cases spirorchid vasculitis was associated with fatal disseminated bacterial infections. Other sporadic, naturally-occurring diseases included mycotic pneumonia, bacterial meningoencephalitis and a miscellany of gastrointestinal conditions, including chronic intestinal tympany and obstipation, for which the underlying cause could not always be determined. Evidence indicated that gastrointestinal motility in C. mydas was prone to both direct and indirect disturbance and that tympany and obstipation could be final common outcomes of a range of insults. Eighteen abnormally buoyant turtles were examined during this study. The cause could usually be ascribed to an underlying disease, including (in decreasing order of frequency) trapped internal gas, usually intestinal; neurological disease such as traumatic brain injuries; and pulmonary disease. In two cases, no underlying cause was detected. Trace metal (arsenic, cadmium, mercury, selenium and zinc) concentrations were determined in the livers and kidneys of 50 turtles of mixed species (mostly C. mydas). These results were considered to provide baseline data for sea turtles in SE Qld. This study offered the largest dataset available for some metals in C. mydas, and provided evidence of high background levels of cadmium as a normal feature for the species. Some unusual age–related trends in metal accumulation were detected. Concentrations of cadmium, zinc and selenium in the kidney decreased with increasing age, whereas zinc concentrations in the liver tended to increase. Determining the impact of disease on wildlife populations is an increasingly necessary task, which will require multidisciplinary teams. Necropsy surveys like the present study are an essential component of the growing field of conservation medicine. In addition to providing data relevant to management, such as the relative proportions of anthropogenic and naturally-occurring mortalities, necropsy surveys can identify a range of endemic pathogens, and help to collect prevalence data for determining disease impacts at the population level.

La forte hétérogénéité de l'écosystème marin se traduit par une production inégale des ressources sur un large éventail d'échelles spatio-temporelles, qui conditionne par conséquent les déplacements des tortues marines. Considéré comme l’un des plus dynamiques au monde, le plateau des Guyanes est une région très complexe d'un point de vue océanographique et qui héberge trois des sept espèces de tortues marines présentes dans le monde (la tortue olivâtre, la tortue verte et la tortue luth). L'objectif de cette thèse était de comprendre comment les contraintes océanographiques peuvent-elles influencer les déplacements en mer de ces trois espèces. Le déploiement de 55 balises satellites sur des femelles reproductrices en Guyane française a permis de fournir des informations sur leurs trajectoires, sur leur comportement de plongée et sur les caractéristiques de leur environnement. Notre étude a mis en évidence une forte plasticité comportementale interspécifique qui semble être principalement dictée par les traits reproducteurs, les stratégies de reproduction, les conditions locales de l'habitat ou encore les adaptations physiologiques. / The strong heterogeneity of the marine ecosystem leads to a patchy distribution of the resources in time and space, shaping therefore the movements of sea turtles. Considered as the most dynamic ecosystem in the world, the Guiana shield is a highly dynamic system which hosts three of the seven sea turtle species in the world (the olive ridley, the green turtle and the leatherback turtle). The aim of this thesis was to understand how the oceanographic constraints can influence the at-sea movements of these three species during the reproduction and the migration phases. The deployment of 55 satellite tags on adult females in French Guiana provided information on their trajectories, their diving behavior and on the environment encountered. Our study shows a strong behavioral plasticity between species, which seems to be mainly dictated by the reproductive traits and strategies, the local conditions of the habitat and the physiological adaptations.

Climate change threatens to disrupt biological systems around the globe, sparking debate over natural capacity for adaptation in a fragmented landscape. Marine turtles are evolutionarily ancient and have survived millions of years of prehistoric climate change, but are threatened by the rapidity of modern warming and a history of severe overexploitation that has left most populations depleted. This thesis explores a nesting aggregation of the green turtle (Chelonia mydas) in northern Cyprus, where a longitudinal programme of both intensive and extensive monitoring enables insight into individual and population level parameters and processes. Nesting on the two coastlines covered by this project is in the early stages of recovery, possibly in response to exhaustive nest protection efforts over the last twenty years. Saturation tagging at one key site allows us to confirm that recruitment of new breeders is an important driver of this trend, and that average clutch frequency has remained stable around three nests per female per year, validating nest-count derived abundance estimates at a regional scale. Concern has been raised, however, regarding recent changes in fishing practices which are impacting the local juvenile neritic phase, which may have a lagged effect on the recovery of this nesting population. A collaborative tracking effort including all other countries with major nesting in the Mediterranean allows us to identify major foraging grounds for this species, with two hotspots accounting for >50% of tracked individuals, as well as coastal and pelagic seasonal corridors of high use. Bycatch levels and mortality rates for turtles in these key areas are largely unknown and should be prioritised for investigation. Hatchling sex ratios from the main study beach are extremely female-biased (estimated 97% female for the twenty year period 1993-2012). A 1oC rise in average incubation temperatures threatens near complete hatchling feminisation on this beach, whilst a 2oC rise could reduce hatch success to less than 50%. Thermal effects on hatchling morphometrics are evident, with a 1oC rise in temperature reducing average length, width and weight by 1%, 2% and 3% respectively. More favourable incubation conditions were found early in the season, in deeper nests laid by larger females, and on beaches of lighter sand. In contrast, adult sex ratios at the main site are male-biased, posing questions regarding sex-specific survival rates and optimal hatchling sex ratios. A phenological shift towards earlier nesting is demonstrated for the first time in this species, and could potentially ameliorate warming effects. Carry-over climate forcing effects from the foraging ground influence the breeding frequency of individuals, driving population level responses in annual magnitude of nesting. This work emphasises the utility and necessity of long-term individual-based monitoring programmes in elucidating population trends and climate responses in iteroparous species with non-annual breeding.

<p dir="ltr">The Northwest Atlantic Ocean, which surrounds the US eastern coastline, is an area rich in marine life. The US eastern coastline is also highly urbanized, resulting in a lot of pollutants (like heavy metals) entering the marine environment. This is of concern for long-lived marine species like sea turtles. Since sea turtles are long-lived and highly migratory, their tissues can often incorporate these pollutants through environmental and dietary exposure. I collected tissue samples from 5 different sea turtle populations in the Northwest Atlantic and analyzed them for concentrations of silver (Ag), aluminum (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), selenium (Se) and zinc (Zn) using an Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The first chapter looks at skin (reflects exposure ~1 year ago) and scute (reflects exposure from 4-6 years ago) samples collected during necropsies of juvenile green (<i>Chelonia mydas</i>) (n=8), Kemp’s ridley (<i>Lepidochelys kempii</i>) (n=30) and loggerhead (<i>Caretta caretta</i>) (n=17) turtles that were found cold-stunned in Cape Cod Bay, Massachusetts. In scute samples, the heavy metal with the highest concentration for green turtles was iron, zinc for loggerhead turtles, and arsenic for Kemp’s ridley turtles. In skin samples, the heavy metal with the highest concentration for green turtles was iron, arsenic for loggerhead turtles, and aluminum for Kemp’s ridley turtles. Overall, I found scute samples to have higher heavy metal concentrations than skin samples. The second chapter looks at scute samples collected from loggerhead turtles of different life stages. These samples were collected during necropsies of cold-stunned loggerhead turtles from Cape Cod Bay, Massachusetts (CCB; n=17), as well as from live loggerhead turtles in the Mid-Atlantic Bight (MAB; n=37) and off the coast of North Carolina (NC; n=9). We also collected commonly known loggerhead turtle prey items including whelk (<i>Buccinum undatum</i>) (n=12), Atlantic scallop (<i>Placopecten magellanicus)</i> (n=10) and Jonah crab (<i>Cancer borealis</i>) (n=5) from the Mid-Atlantic Bight region to study the occurrence of biomagnification through trophic pathways. NC loggerhead turtles had higher heavy metal concentrations than other locations except for cadmium and zinc, where CCB loggerhead turtles were higher. I found that all heavy metals except silver, cadmium, and lead appear to be biomagnified (TTF>1) in loggerhead turtles. These two chapters provided baseline information on heavy metal concentrations in sea turtles in east coast US.</p>