Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-02-12T17:34:13Z No. of bitstreams: 1 robsonhenriquedecarvalho.pdf: 3308952 bytes, checksum: 15b338c6950df1516539e069a54dbee2 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-02-26T12:21:34Z (GMT) No. of bitstreams: 1 robsonhenriquedecarvalho.pdf: 3308952 bytes, checksum: 15b338c6950df1516539e069a54dbee2 (MD5) / Made available in DSpace on 2016-02-26T12:21:34Z (GMT). No. of bitstreams: 1 robsonhenriquedecarvalho.pdf: 3308952 bytes, checksum: 15b338c6950df1516539e069a54dbee2 (MD5) Previous issue date: 2014-02-27 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A costa brasileira é área prioritária para conservação das tartarugas marinhas, pois cinco das setes espécies de tartarugas existentes no mundo podem ser encontradas no Brasil, estando todas ameaçadas de extinção. As ameaças para esses animais incluem: Ocupação da costa, poluição, doenças e principalmente capturas incidentais em artefatos de pesca. Resgatar a sabedoria popular de pescadores e o conhecimento local é essencial para a conservação desses quelônios. O Objetivo desse trabalho foi apresentar e comparar o conhecimento de pescadores sobre tartarugas de três cidades do sul do Espírito Santo. O estudo foi realizado nas cidades de Anchieta, Piúma e Guarapari, ES, Brasil. As informações relacionadas ao conhecimento local e interação entre as pessoas e tartarugas marinhas foram coletadas através de entrevistas utilizando questionário semiestruturado. Foram entrevistados 44 pescadores e 7 marisqueiras, sendo 19 pescadores em Piúma, 5 pescadores e 7 marisqueiras em Guarapari e 20 pescadores em Anchieta. A tartaruga-de-couro é mais conhecida em Piúma e a verde a mais conhecida em Anchieta e Guarapari. As características que permitem diferenciar os animais são formas do casco e cor e os animais são conhecidos por vários nomes populares. Em Piúma e Anchieta foram citadas altas taxas de captura em rede e consumo de carne de tartaruga. As atitudes em relação as tartarugas marinhas e o conhecimento sobre a reprodução desses animais são diferentes em cada cidade devido a fatores como: Cidade que reside e arte de pesca. Os resultados desse estudo indicam que a conservação de quelônios marinhos requer conhecimento das práticas diárias de comunidades locais e as peculiaridades envolvidas na relação entre os pescadores e as tartarugas marinhas, além do levantamento dos impactos causados pelas práticas diárias. / The Brazilian coast is a priority for conservation of sea turtles, because five of the seven species in the world and they can be found in Brazil and all of them are endangered. The threats to this animal include: Occupancy of the coast, pollution, disease and mostly incidental catches in fishing artifacts. Rescue the folk wisdom of fishermen and local knowledge is essential to the conservation of these turtles. The aim of this present study was to show and compare the knowledge of fishermen on turtles from three cities in southern of Espírito Santo. The study was conducted in the cities of Anchieta, Piuma and Guarapari, ES, Brazil. The information related to local knowledge and interaction between people and sea turtles were collected through interviews using a semistructured questionnaire. Forty-four fishermen and seven seafood were interviewed, where nineteen were fishermen on Piuma, five fishermen and seven seafood in Guarapari and twenty fishermen in Anchieta. The leatherback turtle is best known in Piúma and the Green one is best known in Anchieta and Guarapari. The characteristics to differentiate these animals are shell shape and color and they are known by several common names. In Piuma and Anchieta were cited high rates of capture on fishing net and consumption of turtle meat. Attitudes and knowledge about reproduction is different in each city due to factors such as location and fishing gear. The results of this study indicate that the conservation of marine turtles requires knowledge of the practices of local communities and the peculiarities involved in the relationship between fishermen and turtles, and a survey of impacts caused by everyday practices.

A beach conservation programme protecting nesting loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) sea turtles in South Africa was started in 1963. As initial numbers of nesting females were low for both species (107 loggerheads and 24 leatherbacks) it was proposed that the protection of eggs, hatchlings and nesting females along the nesting beach would induce population growth and prohibit local extinction. Today, 50 years later, the loggerhead population exceeds 650 females per annum, whereas the leatherback population counts about 65 nesting females per year. The trend for leatherback turtles is that the population has been stable for about 30 years whereas loggerheads are increasing exponentially. Thus, this thesis investigated several life-history traits to explain the differing responses to the ongoing beach conservation programme. Reproductive output and success were assessed for both species; it was hypothesised that environmental conditions are sub-optimal for leatherback turtles to reproduce successfully. It was ascertained that nesting loggerhead females deposit larger clutches than leatherbacks (112 ± SD 20 eggs and 100 ± SD 23 eggs, respectively), but that annual reproductive output per individual leatherback female exceeds that of loggerhead turtles (±700 eggs and ±448 eggs, respectively) because they exhibit a higher intra-seasonal nesting frequency (leatherbacks n = 7 and loggerheads n = 4 from Nel et al. 2013). Emergence success (i.e. the percentage of hatchlings produced) per nest was similar for both species (loggerhead 73.6 ± SD 27.68 % and leatherback turtles 73.8 ± SD 22.70 %), but as loggerhead turtles nest in greater numbers, i.e. producing more hatchlings per year, the absolute population growth potential favours the loggerhead turtle. The second factor investigated was sex ratio because sea turtles display temperature-dependent sex determination (TSD) where extreme incubation temperatures can skew the sex ratio (i.e. feminising or masculinising a clutch). It was suspected that leatherback turtles are male-biased as this is the southern-most rookery (for both species). Further, leatherback nests are generally closer to the high tide mark, which might induce a cooling effect. Standard histological techniques were applied to sex hatchlings and a generalized linear model (GLM) was used to approximate annual sex ratio. Loggerhead sex ratio (2009 - 2011) was estimated at 86.9 ± SE 0.35 % female-biased; however, sufficient replication for the leatherback population was only obtained for season 2010, which indicated a 97.1 % (95 % CI 93.3 - 98.7) female bias. Both species are, thus, highly female-biased, and current sex ratio for leatherback turtles is not prohibiting population growth. Current sex ratios, however, are not necessarily indicative of sex ratios in the past which would have induced present population growth. Thus, to account for present population growth profiles, sex ratios from the past needed to be ascertained. Annual sex ratios (1997 - 2011) were modelled from historical air and sea surface temperatures (SSTs) but no significant change over time was obtained for either loggerhead or leatherback turtles (linear regression; p ≥ 0.45). The average sex ratio over this 15-year period for the South African loggerhead turtle was approximated at 77.1 ± SE 3.36 % female-biased, whereas leatherbacks exhibited a 99.5 ± SE 0.24 % female bias. Re-analysing data from the mid-80s by Maxwell et al. (1988) also indicated a 77.4 % female bias for the South African loggerhead population. It is, therefore, highly likely that sex ratios of the South African loggerhead and leatherback sea turtle populations have been stable for at least three decades and are not accountable for the differing population growth profiles as they are displayed today. Another possibility that could explain the opposed population growth profiles is the time taken for animals to replace themselves, i.e. age at maturity. It was suspected that age at maturity for the South African loggerhead turtle is comparable with that for leatherbacks. Using data from a 30-year mutilation tagging experiment (i.e. notching), age at first reproduction for South African loggerhead females was estimated. Results ranged broadly but a mean of 36.2 ± SD 7.71 years was obtained using a Gaussian distribution. Age at reproduction of the South African leatherback turtle was not determined but the literature suggests a much younger age of 13.3 - 26.8 years (Zug & Parham 1996, Dutton et al. 2005, Avens et al. 2009, Jones et al. 2011). Therefore, population growth would favour leatherback turtles as they exhibit a much shorter generation time. Finally, it was concluded that all life-history parameters investigated favour leatherback turtles, yet loggerheads are displaying population growth. However, as there were no obvious constraints to population growth on the nesting beach, it is suspected that population growth of the South African leatherback turtle is either unobserved (due to inadequate monitoring not capturing sufficient numbers of nesting events to establish a trend) or that population growth is prohibited by some offshore factor such as industrial fisheries (or some other driver not yet identified). Monitoring should, thus, be expanded and offshore mortality monitored as the leatherback population nesting in South Africa is still critically endangered with nesting numbers dangerously low.

Loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) sea turtles as well as their eggs and hatchlings have been protected on their nesting beach in South Africa (SA) since 1963. Both nesting populations were expected to show similar trends in recovery following the application of identical protection and conservation measures. The loggerhead nesting population has responded favourably to these protection efforts. In contrast, the leatherback nesting population showed an initial increase but is currently stable. The reason for this difference in response is thought to be due to differential offshore mortality of these two species. This prompted an investigation into the different sources of sea turtle mortality in the South Western Indian Ocean (SWIO). Specific aims were to identify and quantify sources of loggerhead and leatherback mortality on nesting beaches as well as in the oceans. Reasonable survivorship at all age classes is important to ensure recruitment of new nesting individuals into sea turtle populations. Mortality of nests, eggs per nest and hatchlings were quantified over two seasons for the loggerheads and leatherbacks nesting in SA. The beach was patrolled on foot to encounter and record females emerging from the ocean and later, hatchlings from their nests. The nests were then monitored during the incubation period and excavated once hatched. The fates of 925 nests were determined during these two nesting seasons (2009/2010 and 2010/2011). The main source of loggerhead and leatherback nest destruction was predation (8.6 percent and 15.7 percent respectively) followed by nest erosion (2.2 percent and 6.3 percent respectively). Overall nest success was high but higher for loggerheads (89 percent) than for leatherbacks (78 percent). The main cause of egg mortality for both species was early developmental arrest, followed by predation by ants and ghost crabs. Hatchlings en route to the sea were almost exclusively predated by ghost crabs (4.2 percent of emerged loggerhead hatchlings and 3.2 percent of emerged leatherback hatchlings). It appears that both species benefit from the coastal conservation efforts. When sea turtles leave the nesting beach, either as hatchlings or adults, conservation and monitoring becomes more difficult and sea turtles are exposed to a multitude of threats, including anthropogenic threats. Age classes tend to be spatially separated due to different habitat and dietary requirements. The type of threat sea turtles are exposed to thus depends on the current age class. Offshore sources of mortality in the SWIO were identified and where possible loggerhead and leatherback mortality was quantified and mapped spatially. Loggerheads were mostly exposed to and had the highest mortality in the artisanal fisheries in the SWIO (> 1000 per annum), inshore trawling (ca. 41 per annum), shark nets (protective gill nets) (21.6 ± 6.7 per annum) and the pelagic longline fishery (5.0 ± 4.4 per annum). In contrast, leatherbacks with a pelagic lifestyle, were mostly exposed to pelagic longline fisheries (7.8 ± 7.8 per annum). A spatial analysis of fishing activities indicated that leatherback home ranges overlapped 41percent with pelagic longline fishing activity in the SA EEZ, whereas the overlap between pelagic longliners and loggerhead home ranges was 29 percent. The quantified sources of mortality provide some explanation for the trend in the loggerhead nesting population but not the trend in the leatherback nesting population. Hatchling survivorship to adulthood was estimated to determine the viability of the two nesting populations as well as to determine whether offshore mortality was responsible for the difference in recovery of the two populations. Loggerhead hatchling survivorship to adulthood was estimated at between 2 and 10 per 1000 hatchlings, the minimum requirement for an increasing population. The adopted sophisticated model shows that leatherbacks have a survival rate of 5 to 10 per 1 000 hatchlings. However, this suggests that the population is increasing, but the leatherback population is stable. Perhaps the age to maturity of SA leatherbacks is greater than 12 years, or fisheries-related mortality affects younger age classes than initially thought. It is therefore recommended that the turtle monitoring area is extended to include other potential nesting grounds. In addition, observer or monitoring programs for commercial as well as artisanal fisheries needs to be extended throughout the SWIO to quantify sea turtle mortality. Ultimately a comprehensive multi-regional approach is required for the conservation of these highly migratory species.

Stable isotope analysis is a powerful tool that can be used to describe a population’s foraging niche by identifying basal resource use, trophic feeding levels, environmental stability, seasonal ecological variation, important shifts in life history, ontogenetic shifts, intraspecific habitat use, and population dynamics. Describing these relationships in endangered marine turtle populations and their critical foraging grounds is essential for determining informed management decisions. This study systematically describes the foraging niche of hawksbills Eretmochelys imbricata, and green turtles, Chelonia mydas in Buck Island Reef National Monument, U.S. Virgin Islands, a critical habitat for nesting and foraging. It assesses the relationships within and between the species in terms of overlap, annual and seasonal variation, and life history and feeding strategies within the community. Most importantly it describes these relationships with metrics that can be used in global comparisons or to measure change in local conditions. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

<p>Colonization by bacteria and fungi has been shown to reduce hatching success of sea turtle nests. Presence of microbial pathogens is commonly associated with egg failure, and in some species, it has even been shown to cause up to 90% nest mortality. Developing sea turtle embryos can only rely on non-specific defenses, such as the eggshell and the proteins present in the egg albumen. For a long time, it has been suggested that the fluid in which the eggs are coated during oviposition may contain antimicrobial properties that might protect eggs against potential pathogens that are found in the egg chamber. This study aimed to evaluate the antimicrobial properties of the cloacal fluid of loggerhead sea turtles. Cloacal fluid samples were collected at the Wassaw National Wildlife Refuge, Georgia during the 2021 nesting season (June-July). Protein fractionation of the samples was carried out using commercially available ultracentrifugation devices of 3K, 10K and 30K molecular cut-off weights. A microplate-based turbidimetric growth inhibition assay recorded the antimicrobial activity of the peptide fractions and the crude extract. We found that the cloacal fluid of loggerheads has antimicrobial properties against <i>Serratia marcescens</i> and <i>Morganella morganii</i>, and some mild action against <i>Pseudomonas aeruginosa</i>. Results obtained from the microplate-based turbidimetric assay were confirmed by assessing viability of cells upon 24 hours of exposure to the fluid. Furthermore, this study found that the cloacal fluid contains proteins with molecular weight ranging from approximately 5 to 250 kDa, and that proteins with higher molecular weights (MW>30kDa) are found in greater abundance. Further studies are needed to understand the mechanism of action of the proteins and peptides present in the cloacal fluid to potentially develop antimicrobial compounds that can be used to increase hatching success globally.</p>

Marine turtle reproductive success is strongly correlated with the stability and quality of the nesting environment. Because females show fidelity to key nesting beaches, the management and physical characteristics of these beaches directly affect future generations of marine turtles and may be essential for the recovery of these threatened and endangered species. The impacts of beach restoration on loggerhead turtles (Caretta caretta) and on green turtles (Chelonia mydas) were investigated. Previous studies concerning beach nourishment projects have focused on loggerhead turtles. I compared data between nourished and non-nourished areas and between loggerhead and green turtles. I found, at one season post-nourishment, negative effects on nesting success and no significant effect on reproductive success for both loggerheads and established the same relationships with green turtles. Physical attributes of the fill sand, which did not facilitate acute scarp formation or severe compaction, did not physically impede turtles in their attempts to nest. Instead, the decrease in nesting success was attributed to an absence of abiotic and or biotic factors that cue nesting behavior. The increase in loggerhead nesting success rates during the second season post-nourishment was attributed to the equilibration process of the seaward crest of the berm. After the beach was restored, both species of turtles placed nests significantly farther from the water in the nourished area than in the non-nourished area. Green turtles nested on or near the dune and loggerheads nested on the seaward crest of the berm. The tendency of loggerheads to nest closer to the water resulted in more loggerhead than green turtle nests being "washed out" by erosion during the equilibration process. There was a significant increase in hatching success only for loggerheads when wash outs were excluded, thus illustrating the importance of nest placement and the detrimental effects of the equilibration process to the reproductive success of loggerheads. A decrease in reproductive output occurred during the first season post-nourishment. The reduction in the estimated total number of hatchlings produced (reproductive output) was a consequence of decreased nesting success lowering nest numbers. This reduction demonstrates that, regardless of similar reproductive success rates, marine turtles incurred net losses during the first season following nourishment. These results further reveal the impacts of decreased nesting success and the importance of minimizing excessive non-nesting emergences associated with beach nourishment.

No description available.

Thesis (DTech. degree in Nature Conservation.)--Tshwane University of Technology, 2010. / Hawksbill sea turtles (Eretmochelys imbricata) have been reduced by more than 80% worldwide in the last century and are considered critically endangered. Although nesting populations have been subject to numerous studies, there is a considerable lack of knowledge pertaining to the in-water behaviour and ecological functions of wild foraging hawksbill populations. This is especially true for the Western Indian Ocean as important topics such as habitat use and dietary items have scarcely been explored. Between 2006 and present, more than 178 hours of in-water observations of foraging hawksbill activity was recorded on a small insular reef at D'Arros Island, Seychelles. Most of the 827 sightings were of known, resident turtles (> 90%), facilitating analyses on both a population and individual level. Habitat types were identified and described, turtle densities estimated, population dynamics established, home ranges calculated, food items identified, food intake quantified, feeding behavior described, food resources quantified, diet selectivity indices calculated, intra/interspecific competition quantified and activity and dive patterns were described.

Dry Tortugas National Park (DRTO) consists of 261.8 km2 in the Gulf of Mexico and provides protection to marine species facing a multitude of threats. Among the many species that utilize DRTO is the green sea turtle (Chelonia mydas). I examined seven years of capture-recapture data to determine how the body condition (using Fulton’s equation, K = M/L3) and growth rate for juvenile green turtles vary within, and among size classes in DRTO, and how those rates compare to similar populations in other locations. Body conditions ranged from 0.77 to 1.71 (mean 1.3 SD ± 0.16). Growth rates ranged from 2.5 to 9.9cm/yr (mean 5.5 cm/yr SD ± 1.25), which is a high growth rate for green turtles. Establishing growth rates and body condition for a specific population can provide insight into life history and health of that population, as well as important data for comparison to populations in other areas. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015 / FAU Electronic Theses and Dissertations Collection

Little is known about the visual capabilities of marine turtles. The ability to discriminate between colors has not been adequately demonstrated on the basis of behavioral criteria. I used a three-part methodology to determine if color discrimination occurred. FIrst, I exposed naèive, light-adapted hatchlings to either a blue, green or yellow light. I manipulated light intensity to obtain a behavioral phototaxis threshold to each color, which provided a range of intensities we knew turtles could detect. Second, I used food to train older turtles to swim toward one light color, and then to discriminate between the rewarded light and another light color ; lights were presented at intensities equally above the phototaxis threshold. Lastly, I varied light intensity so that brightness could not be used as a discrimination cue. Six turtles completed this task and showed a clear ability to select a rewarded over a non-rewarded color, regardless of stimulus intensity. Turtles most rapidly learned to associate shorter wavelengths (blue) with food. My results clearly show loggerheads have color vision. Further investigation is required to determine how marine turtles exploit this capability. / by Morgan Young. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.