The concept of temperature dependent sex determination (TSD) has been somewhat of an evolutionary enigma for many decades and has had increased attention with the growing predictions of a changing climate, particularly in species that are already threatened or endangered. TSD taxa of concern include marine turtles, which go through various life stages covering a range of regions. This, in turn, creates difficulties in addressing basic demographic questions. Secondary sex ratios (from life stages post-hatchling) were investigated by capturing juvenile green turtles (Chelonia mydas), 22.6-60.9 cm in straight carapace length (SCL), from three developmental areas along the east coast of Florida (a region known to have important juvenile aggregations) by analyzing circulating testosterone levels. All three aggregations exhibited significant female biases with an overall ratio of 3.2:1 (female: male). The probability of a turtle being female increased as the size of the individual decreased. Ratios obtained in this study were slightly less female-biased, but not significantly different, than those observed in the late 1990s. However, they were significantly more biased than those found in a late 1980s pilot study. The shift to significantly female-biased ratios may be beneficial to a recovering population, an evolutionary adaptation, and is common among juvenile aggregations. A more skewed female bias in smaller size classes may be indicative of recent, warmer periods during incubation on the nesting beaches. This female bias could become more exaggerated if temperatures meet future climate warming predictions.

The influence of feeding juvenile female leopard tortoises (Geochelone pardalis, n=18) a commercially available, complete, extruded feed three (3) or seven days (7) per week on dry matter and digestible energy intake, apparent digestibility of dry matter, organic matter, gross energy and fiber fractions, animal body weight and measurements, digesta transit time, rate of passage, and indigestible fill was evaluated. Both feeding frequencies are commonly practiced with captive tortoises. When fed 7 compared to 3 days per week, dry matter and digestible energy intake was greater. Tortoises gained more g BW, but not when adjusted per kg initial BW. When fed 7 compared to 3 days per week, tortoises grew more in plastron width (PW) and carapace height (CH), but not midline straight carapace length (MSCL), and grew more in calculated shell volume (i.e., a calculated estimate of shell volume using MSCL, PW, and CH), with a higher calculated body condition index (BCI). Providing short fasts (i.e., feeding 3 compared to 7 days per week) may be useful in slowing tortoise growth when animals are provided food ad libitum. In general, ad libitum feeding, especially of a highly digestible extruded feed, is not recommended for captive juvenile G. pardalis, especially when offered food daily. With two data points (detected as outliers) removed due to low fecal output (and resulting unrealistically high apparent digestibility of all nutrients analyzed) of two animals when fed 3 days per week, apparent digestibility of cellulose in tortoises fed 7 (n=18) compared to 3 (n=16) days per week was lower, but no differences were detected in DM, OM, GE, or any other fiber fractions analyzed. Transit time (TT1) was shorter and indigestible fill was higher in tortoises (n=18) fed 7 compared to 3 days per week, regardless of percent Cr marker recovered. With four animals removed due to <50% Cr marker recovery, tortoises fed 7 compared to 3 days per week exhibited shorter mean retention time (RGIT), with no differences in digesta transit or indigestible fill. Longer digesta retention when food availability included short periods of fasting may have allowed tortoises to extract more energy from cellulose.

Seagrass is a valuable and important habitat, providing services such as coastal protection, supporting fisheries, and carbon sequestration. However, it is challenging to map accurately, as remote sensing has limits to how deep in the water column it can penetrate, and uncertainties such as distinguishing between algae and seagrass. Seagrass can exist at depths of theoretically 90 m deep in ultraoligotrophic waters, meaning that there is much of this habitat that cannot be mapped by remote sensing. Green turtles are an ideal candidate to help find seagrass blue carbon resources in the Red Sea. They go through an ontogenetic dietary shift to become almost completely herbivorous, and have a high fidelity to foraging sites. In this study we aim to assess the use of green turtles Chelonia mydas in discovering seagrass blue carbon. We use telemetry from 53 turtles tagged over 2018, 2019, and 2021 to map their foraging areas. 50 out of the 53 (94.34%) foraging sites had not been visited by previous seagrass studies in the Red Sea. We visited 18 locations in 14 of these foraging sites to ground truth them, and all 14 foraging sites (100%) had seagrass present. Comparatively, 18 out of 30 sites where seagrass was indicated by the remote sensing-based Allen Coral Atlas showed no seagrass. The turtles were seen to favour travelling shorter distances, thus it will be necessary to expand the area of tagging in order to achieve complete coverage of the Red Sea. Approximately 1/3 of the visited sites were deeper than 8 m, and so out of range of remote sensing, showing that considerable blue carbon resources may be discovered with the use of turtles. Samples were taken for carbon stock estimation from the ground truthed sites. A mean carbon stock of 4.89 ± 0.83 kg Corg m-2 was estimated for 1 m depth sediment. In the future it is important to develop methods for mapping the surface areas of the deep and inaccessible seagrass habitats that the turtles discover.

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.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-09-22T11:26:45Z No. of bitstreams: 1 adrianafonsecadefaria.pdf: 930419 bytes, checksum: 95f7e760beeded23d0bdca1ba20b6294 (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-09-26T20:28:21Z (GMT) No. of bitstreams: 1 adrianafonsecadefaria.pdf: 930419 bytes, checksum: 95f7e760beeded23d0bdca1ba20b6294 (MD5) / Made available in DSpace on 2016-09-26T20:28:21Z (GMT). No. of bitstreams: 1 adrianafonsecadefaria.pdf: 930419 bytes, checksum: 95f7e760beeded23d0bdca1ba20b6294 (MD5) Previous issue date: 2010-03-17 / Um grande número de juvenis da espécie Chelonia mydas (Linnaeus, 1758) utiliza o litoral norte do Estado de São Paulo como área de alimentação, com grande ocorrência no Município de Ubatuba. Existem poucos trabalhos sobre a dieta desta espécie no Brasil. Por esta razão, o presente estudo tem como objetivo determinar a dieta, além de qualificar e quantificar os itens alimentares ingeridos por esses espécimes. Para a determinação da dieta, 20 conteúdos estomacais de juvenis de C. mydas foram analisados. Estes animais foram encontrados mortos ao longo da costa de Ubatuba e encaminhados à equipe do Projeto TAMAR/ICMBio. Os dados biométricos dos animais coletados indicam que todos os indivíduos podem ser considerados juvenis, pois apresentaram comprimento curvilíneo da carapaça (CCC) entre 35 e 60 cm e peso entre 7 e 8 Kg. Dos itens presentes no conteúdo estomacal destacaram-se os vegetais (algas e gramas marinhas) com 93,64% do total, seguido de material antrópico com 4,71% e animal com 1,65%. As algas da família Rhodophyta foram as mais abundantes onde constatou-se um maior volume para Pterocladiella capillacea (44,5V%) e Chondracanthus acicularis (42,3V%). Do material antrópico ingerido o plástico mole foi o mais abundante (54,3%) e o nylon o mais freqüente (45%). Com base nestes resultados salienta-se a importância de programas de conservação para esta espécie em áreas de alimentação. / A large number of Chelonia mydas (Linnaeus, 1758) young utilizes the northern coast of São Paulo state as feeding grounds. Great parts of these areas are located in Ubatuba. At this moment, there is a few data on C. mydas feeding habits in Brazil. Because of that, the objective of this study was to determine the C. mydas diet, and qualify and quantify its diet items. Twenty stomachs of C. mydas young individual were analyzed. These animals were found dead along Ubatuba coast and sent to Project TAMAR/ICMBio. All individuals were considered young because the curved carapace length was between 35 and 65, and the weight was between 7 and 8 Kg. Vegetables were the most frequent item found in the stomachs (seaweed and marine grass) representing 93,64% of the total, followed for anthropic material (4,71%) and animal material (1,65%). The seaweed family of Rhodophyta was the most abundant with Pteocldiella capillacea and Chodracanthus acicularis having the largest volumes, 44,5% and 42,3% respectively. Among the anthropic material, soft plastic was the most abundant (53%) and nylon the most frequent (45%). This results shows the importance of conservation programs for C. mydas among your feeding areas.

Made available in DSpace on 2016-06-02T19:26:23Z (GMT). No. of bitstreams: 1 GUSMAO_Juliana_2013.pdf: 2002037 bytes, checksum: 764c92fab171e138eea762ca82c8ad4d (MD5) Previous issue date: 2013-11-18 / Financiadora de Estudos e Projetos / The Iguape-Cananéia Estuarine-Lagoon Complex has been described as an area for feeding and development of young sea turtles of the Chelonia mydas (green sea turtle) species, besides having recorded the incidence of other marine turtle species present at the Brazilian coast (Caretta caretta, Lepidochelys olivacea, Dermochelys coriacea and Eretmochelys imbricata). The region also presents several caiçara (population from coastal regions) nucleuses which have small-scale fishing as their main source of income, making important to analyze existing interactions between fishermen and sea turtles. The objective of the present study was to describe the interaction of the caiçara communities of Pedrinhas and Pontal de Leste with sea turtles, and the interaction between sea turtles and the artisanal gillnetting, from the fishermen s perspective. Field researches were performed using semi-structured interviews via Snow Ball technique, enabling the identification of the key informers by their peer s recognition. The results showed that the caiçara community of Pontal de Leste, more isolated from the urban centers and having fishing as exclusive activity, presented greater presence of sea turtles in its culture, as well as higher nutritional dependency from sea turtle meat when climate conditions render fishing impossible for long periods of time. At the Pedrinhas community, as it is closer to urban centers and as it has alternative income activities due to tourism, the presence of the sea turtle in the local culture resides mainly at the memories of the older interviewed community members. In both communities knowledge gaps were verified, which could be clarified with educational actions, and the importance of gillnetting for the caiçara and the negative impact it may cause to sea turtles were also verified, being thus vital, the execution of new studies which shall enable the understanding of the magnitude of such interaction. The results obtained aim at generating information for conservation plans so as to minimize the mortality of sea turtles, protecting cultural practices of such communities; thereby, educational activities and management guidelines were proposed, aiming at integrating the political management of natural resources and conservation strategies with the conduct of the local traditional community. / O Complexo Estuarino-Lagunar de Iguape-Cananéia foi descrito como uma área de alimentação e desenvolvimento para juvenis de tartarugas marinhas da espécie Chelonia mydas (tartaruga-verde), além de ter registrado a ocorrência das outras espécies de tartarugas marinhas presentes na costa brasileira (Caretta caretta, Lepidochelys olivacea, Dermochelys coriacea e Eretmochelys imbricata). A região apresenta também vários núcleos caiçaras que têm na pesca artesanal sua principal fonte de renda, o que torna, importante, avaliar as interações existentes entre os pescadores e as tartarugas marinhas. O objetivo deste estudo foi descrever a interação das comunidades caiçaras de Pedrinhas e Pontal de Leste, com as tartarugas marinhas e destas com a pesca de emalhe artesanal, sob a perspectiva dos pescadores. Foram realizadas pesquisas de campo utilizando entrevistas semi-estruturadas através da técnica Bola de Neve , que possibilitou identificar os informantes-chave pelo reconhecimento por seus pares. Os resultados evidenciaram que a comunidade caiçara de Pontal de Leste, mais isolada dos centros urbanos e tendo como única atividade a pesca, apresentou maior presença das tartarugas marinhas em sua cultura, assim como maior dependência nutricional da carne de tartaruga marinha quando as condições climáticas impossibilitam a pesca por longos períodos. Na comunidade de Pedrinhas, por estar próxima aos centros urbanos e ter atividades alternativas de renda, devido ao turismo, a presença da tartaruga marinha na cultura local reside principalmente na memória dos entrevistados mais antigos. Em ambas as comunidades evidenciou-se lacunas de conhecimento que poderiam ser esclarecidas com ações educativas, verificou-se também a importância da rede de emalhe para o caiçara e o impacto negativo que esta pode causar às tartarugas marinhas, sendo imprescindível, portanto, a realização de novos estudos que possibilitem compreender a dimensão desta interação. Os resultados obtidos visam gerar informações para planos de conservação de forma a minimizar a mortalidade das tartarugas marinhas, protegendo as práticas culturais dessas comunidades, desta forma, diretrizes de ações educativas e de gestão foram propostas, objetivando integrar a gestão política dos recursos naturais e estratégias de conservação com o comportamento da comunidade tradicional local.

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.

Terrapins are one of the most endangered vertebrate groups, with almost half of the more than 300 extant species threatened with extinction. This study was conducted to investigate parasite host-switching from the invasive American Red-eared slider, Trachemys scripta elegans, to the native Mediterranean pond terrapin, Mauremys leprosa in natural environments in southern France and Spain. The study also included a risk assessment approach that was developed to assess the viability of the native M. leprosa terrapins in a small river of southern France. The diversity of haemogregarine parasites within South African terrapins was also explored. The thesis is structured as follows: CHAPTER 1 gives a broad introduction to reptiles and chelonians as well as the importance of chelonians in ecosystems with emphasis to the threats that are driving terrapins to decline. The various terrapin species examined during this study as well as the parasite groups of interest (Monogenea and Apicomplexa) are also discussed in detail. CHAPTER 2 documents the extent of platyhelminth invasions from T. s. elegans to natural M. leprosa populations in northern Spain and southern France. From DNA barcoding analysis based on the sequencing of the Cytochrome c Oxidase I gene, the inferred Minimum Evolution tree and p-distance comparisons of closely related haplotypes revealed a greater polystome richness within M. leprosa than expected, suggesting that host switching may take place in natural environments. T. s. elegans would serve as a carrier for a variety of polystomes that usually infest American turtles in their home range. These are transmitted to M. leprosa throughout the south of France, also suggesting that turtle polystomes are not strictly host-specific. CHAPTER 3 investigates polystome egg production under changing environmental conditions. The experimental procedure that was conducted on M. leprosa showed that environmental temperature has an effect on the egg laying rhythm of its parasite, i.e., Neopolystoma sp., with a two day lag of egg production in response to environmental temperature change. Results suggest the adaptability of the parasite to the physiology of their chelonian hosts which are ecthothermic animals. They also show that eggs production may be attributable to the release of host factors like hormones that once secreted may act and stimulate parasite reproduction. CHAPTER 4 relates risk assessment for the viability of the native Mediterranean pond terrapin (M. leprosa) in a natural environment by using the Relative Risk Model (RRM) method, taking into consideration various threats and environmental conditions that may impact this species. CHAPTER 5 examines the diversity of South African terrapin haemogregarines (Protozoa: Apicomplexa: Haemogregarinidae) as well as their phylogenetic placement among haemogregarines based on molecular and morphological evidences. CHAPTER 6 summarizes all findings of the study and explores new ways of Research. / PhD (Zoology), North-West University, Potchefstroom Campus, 2014

Terrapins are one of the most endangered vertebrate groups, with almost half of the more than 300 extant species threatened with extinction. This study was conducted to investigate parasite host-switching from the invasive American Red-eared slider, Trachemys scripta elegans, to the native Mediterranean pond terrapin, Mauremys leprosa in natural environments in southern France and Spain. The study also included a risk assessment approach that was developed to assess the viability of the native M. leprosa terrapins in a small river of southern France. The diversity of haemogregarine parasites within South African terrapins was also explored. The thesis is structured as follows: CHAPTER 1 gives a broad introduction to reptiles and chelonians as well as the importance of chelonians in ecosystems with emphasis to the threats that are driving terrapins to decline. The various terrapin species examined during this study as well as the parasite groups of interest (Monogenea and Apicomplexa) are also discussed in detail. CHAPTER 2 documents the extent of platyhelminth invasions from T. s. elegans to natural M. leprosa populations in northern Spain and southern France. From DNA barcoding analysis based on the sequencing of the Cytochrome c Oxidase I gene, the inferred Minimum Evolution tree and p-distance comparisons of closely related haplotypes revealed a greater polystome richness within M. leprosa than expected, suggesting that host switching may take place in natural environments. T. s. elegans would serve as a carrier for a variety of polystomes that usually infest American turtles in their home range. These are transmitted to M. leprosa throughout the south of France, also suggesting that turtle polystomes are not strictly host-specific. CHAPTER 3 investigates polystome egg production under changing environmental conditions. The experimental procedure that was conducted on M. leprosa showed that environmental temperature has an effect on the egg laying rhythm of its parasite, i.e., Neopolystoma sp., with a two day lag of egg production in response to environmental temperature change. Results suggest the adaptability of the parasite to the physiology of their chelonian hosts which are ecthothermic animals. They also show that eggs production may be attributable to the release of host factors like hormones that once secreted may act and stimulate parasite reproduction. CHAPTER 4 relates risk assessment for the viability of the native Mediterranean pond terrapin (M. leprosa) in a natural environment by using the Relative Risk Model (RRM) method, taking into consideration various threats and environmental conditions that may impact this species. CHAPTER 5 examines the diversity of South African terrapin haemogregarines (Protozoa: Apicomplexa: Haemogregarinidae) as well as their phylogenetic placement among haemogregarines based on molecular and morphological evidences. CHAPTER 6 summarizes all findings of the study and explores new ways of Research. / PhD (Zoology), North-West University, Potchefstroom Campus, 2014