La anidación de la tortuga baula Dermochelys coriacea en la península de Pongara, Gabón, África Central

Diploma de Estudios Avanzados

Increase of a Caribbean leatherback turtle Dermochelys coriacea nesting population linked to long-term nest protection

The leatherback turtle Dermochelys coriacea is considered to be at serious risk of global extinction, despite ongoing conservation efforts. Intensive long-term monitoring of a leatherback nesting population on Sandy Point (St. Croix, US Virgin Islands) offers a unique opportunity to quantify basic population parameters and evaluate effectiveness of nesting beach conservation practices. We report a significant increase in the number of females nesting annually from ca. 18-30 in the 1980s to 186 in 2001, with a corresponding increase in annual hatchling production from ca. 2000 to over 49,000. We then analyzed resighting data from 1991 to 2001 with an open robust-design capture-mark-recapture model to estimate annual nester survival and adult abundance for this population. The expected annual survival probability was estimated at ca. 0.893 (95% CL 0.87-0.92) and the population was estimated to be increasing ca. 13% pa since the early 1990s. Taken together with DNA fingerprinting that identify mother-daughter relations, our findings suggest that the increase in the size of the nesting population since 1991 was probably due to an aggressive program of beach protection and egg relocation initiated more than 20 years ago. Beach protection and egg relocation provide a simple and effective conservation strategy for this Northern Caribbean nesting population as long as adult survival at sea remains relatively high. (c) 2005 Elsevier Ltd. All rights reserved.

Diving behaviour of two Australian bimodally respiring turtles, Rheodytes leukops and Emydura macquarii, in a natural setting

Time-depth recorders were used to investigate the diving performance and behaviour of two bimodally respiring turtle species, Rheodytes leukops and Emydura niacquarii, known to have a high and low reliance on aquatic respiration, respectively. Significant differences in diving performance between R. leukops and E. macquarii were observed in the number of dives/day (39.3 +/- 5.38 vs 112.2 +/- 11.73 dives/day; mean +/- SE), mean dive length (33.1 +/- 7.33 min vs 9.6 +/- 2.26 min) and maximum dive length (623 +/- 104.74 min vs 67.1 +/- 8.14 min), respectively. Differences in diving performance between R. leukops and E macquarii are attributed to the species' reliance (or lack thereof) upon aquatic respiration. Rheodytes leukops displayed a weak bimodal pattern of increased surfacing frequency in the early morning (05:00-07:00) and late afternoon (14:00-18:00), while E. macquarii displayed a strong bimodal pattern of elevated surfacing frequency over similar time periods. Daily patterns of increased surfacing frequency for both species failed to correlate with fluctuating aquatic Po-2 levels or water temperature, and may instead be explained by the heightened activity levels of both species during twilight.

Seasonality and Temperature:Turtles in Hot Water?

Variation in temperature affects the biology of sea turtles at a range of scales. To elucidate the drivers of seasonality of nesting and duration of season, databases across four species of sea turtles (Caretta caretta n=37, Chelonia mydas n=64, Dermochelys coriacea n=44 and Eretmochelys imbricata n=36) at a global scale were created. By using remotely sensed sea surface temperature data, thermal profiles across the nesting season were generated. Duration of nesting season was correlated with latitude in all species but was more tightly coupled with temperature; seasons were significantly longer with increased mean SST. In general, nesting seasonality occurred at warmest time of the year. SST for the month before, month after and the month of peak nesting significantly affected the month of peak nesting.

Caracterização da captura incidental de tartarugas marinhas pela pesca de espinhel pelágico no Nordeste do Brasil

The marine turtles biological characteristics and the impact they have been suffering in consequence of human activities have caused in the last decades the decrease of populations to unsustainable levels. All four of the species described in this paper are registered as endangered in a list by IUCN: Caretta caretta, Lepidochelys olivacea, Chelonia mydas, Dermochelys coriacea. The main causes of such impact include several fishing activities, mostly the surface longline. This paper discusses the monitoring of two foreigner longline fleet along the North East Brazilian coast between October of 2004 and September of 2005. Both operated in the West South Atlantic, one using the Chinese technique and the other the American. The American method s target species is the swordfish (Xiphias gladius), and it is characterized by using squid as bait, J 9/0 offset 5º hook, light sticks and night soaking. It also operates in shallower waters than the Chinese method. The source of information about the efforts and the catches came from onboard observers and were used to calculate the catching rate of turtles over 1000 hooks (CPUE). The American equipment caught more turtles (CPUE = 0,059; N= 103), mainly D. coriacea, while the Chinese longline caught mainly the L. olivacea and presented a CPUE= 0,018 (N= 89). The hooks were most frequently found attached to the mouth of C. caretta, C. mydas, and L. olivacea. The D. coriacea were most frequently caught by hooks externally attached to different parts of their body. There was no significant difference between the hook type catching and most turtles were still alive when released. The results suggest a greater potential of turtle catching by the American method. Besides the statistic tests have showed less interaction between the Chinese equipment and marine turtles, the catches of this fishing technique could have been underestimated due to miscommunication between the onboard observer and the vessel s crew plus the retrieve of the longline during night time

Tartarugas marinhas da Bacia Potiguar/RN: diagnóstico, biologia alimentar e ameaças

This work aimed to study the diversity and distribution of marine sea turtles stranded in Potiguar Basin, Rio Grande do Norte, as well as aspects related to feeding behavior associated with human impacts. The study was conducted through the analysis of data from stranded animals, recorded in a daily monitoring in an area bounded on the north by the municipality of Aquiraz, in the state of Ceará, and the east by the municipality of Caicara do Norte, in the state of Rio Grande do Norte. Stranded dead animals were necropsied and for the analysis of the diet of animals, esophagus, stomach and intestines were fixed in 10% formalin and after that, the stomach contents were sorted and stored in 70% alcohol. Representative fragments of these organs were removed for making histological slides, with a view to histological characterization of the digestive tract. 2.046 occurrences of turtles were recorded during the period from 01/01/2010 to 31/12/2012. The Chelonia mydas species showed the highest number of records and it was observed in 66.81 % (N = 1,367) of cases; followed by Eretmochelys imbricata with 4.45 % (N = 91) and by Lepidochelys olivacea with 1.22% (N = 25). The Caretta caretta and Dermochelys coriacea species were, respectively, 0.93 % (N = 19) and 0.05 % (N = 1) records of strandings. In 26.54 % of cases, it was not possible to identify the species. Regarding the spatial distribution, the stretch A was the one that had the highest number of strandings and a larger number of records were registered in the warm months of the year. The dietary analysis showed that C. mydas fed preferentially on algae; C. caretta had a diet with a predominance of the item "coral´s fragments" and E. imbricata species showed preference for an animal origin material. Related to this anthropic interaction, 57.14 % (n = 76) of animals that died at the rehabilitation s base, showed cause of death due to complications from ingesting debris. According to the data presented, the Potiguar Basin presents itself as an area with important diversity and distribution of marine sea turtle as well is characterized as a feeding and nidification area for these species

Estudo da helmintofauna de tartarugas marinhas procedentes da costa brasileira

Pós-graduação em Biologia Geral e Aplicada - IBB

Nesting In The Clouds: Evaluating And Predicting Sea Turtle Nesting Beach Parameters From Lidar Data

Humans' desire for knowledge regarding animal species and their interactions with the natural world have spurred centuries of studies. The relatively new development of remote sensing systems using satellite or aircraft-borne sensors has opened up a wide field of research, which unfortunately largely remains dependent on coarse-scale image spatial resolution, particularly for habitat modeling. For habitat-specialized species, such data may not be sufficient to successfully capture the nuances of their preferred areas. Of particular concern are those species for which topographic feature attributes are a main limiting factor for habitat use. Coarse spatial resolution data can smooth over details that may be essential for habitat characterization. Three studies focusing on sea turtle nesting beaches were completed to serve as an example of how topography can be a main deciding factor for certain species. Light Detection and Ranging (LiDAR) data were used to illustrate that fine spatial scale data can provide information not readily captured by either field work or coarser spatial scale sources. The variables extracted from the LiDAR data could successfully model nesting density for loggerhead (Caretta caretta), green (Chelonia mydas), and leatherback (Dermochelys coriacea) sea turtle species using morphological beach characteristics, highlight beach changes over time and their correlations with nesting success, and provide comparisons for nesting density models across large geographic areas. Comparisons between the LiDAR dataset and other digital elevation models (DEMs) confirmed that fine spatial scale data sources provide more similar habitat information than those with coarser spatial scales. Although these studies focused solely on sea turtles, the underlying principles are applicable for many other wildlife species whose range and behavior may be influenced by topographic features.

Impact des changements climatiques sur certaines espèces à statut précaire au Québec et analyse des mesures de protection actuelles

Le climat planétaire évolue à une vitesse alarmante. Selon le Groupe d’experts intergouvernemental sur l’évolution du climat, les températures globales pourraient grimper de 3 à 7°C d’ici 2100. Les zones tempérées, comme le Québec, ne seront pas épargnées. Au sein de la province, le climat typique en forêt boréale pourrait se déplacer de 750 km vers le nord pour atteindre le Haut-Arctique dans quelques décennies. D’autres modifications notables du climat se traduisent dans les précipitations, les glaces, les océans, etc. Tous ces changements climatiques constituent une menace grandissante pour la biodiversité. D’ailleurs, ils pourraient devenir la principale cause d’extinction d’espèces dans le futur, surpassant même la dégradation d’habitats et la pollution. Afin de témoigner de la portée des changements climatiques sur la biodiversité, 6 espèces fauniques à statut précaire au Québec sont étudiées dans le cadre de l’essai. Par leurs fortes réponses aux stress, elles agissent à titre de bioindicateurs des changements climatiques. Ces espèces, de classes taxonomiques différentes, sont : le chevalier cuivré (Moxostoma hubbsi), l’ours blanc (Ursus maritimus), la grive de Bicknell (Catharus Bicknelli), la rainette faux-grillon de l’Ouest (Pseudacris triseriata), la tortue luth (Dermochelys coriacea) et le satyre fauve des Maritimes (Coenonympha nipisiquit). L’étude approfondie de ces espèces a permis de relever un total de 47 impacts potentiels des changements climatiques. En majorité, ces impacts concernent la perte d’habitats, l’augmentation de la compétition, la diminution du succès reproducteur et l’entrave à la survie. L’objectif de cet essai est d’évaluer les mesures de protection actuelles permettant de faire face à ces impacts. Bien qu’elles varient grandement d’une espèce à l’autre, elles peuvent être regroupées en quatre grandes thématiques, soit la recherche et le suivi, la gestion des aires protégées, l’adaptation du cadre législatif et l’aménagement écosystémique. L’évaluation de ces mesures a permis de soulever certains constats. En premier lieu, la recherche et le suivi constituent la principale mesure de protection adoptée. En second lieu, il appert que les mesures de protection actuelles manquent de spécificité. En effet, dans la majorité des cas, elles protègent l’espèce de manière indirecte seulement. Au final, dans le but d’améliorer ou de combler les lacunes des mesures de protection actuelles, des recommandations ont été formulées. D’une part, celles-ci présentent des actions concrètes comme la translocation ou l’aménagement écosystémique. D’autre part, elles suggèrent des modifications quant aux méthodes de suivi, à la gestion des aires protégées et aux cadres législatifs.

Caracterização da captura incidental de tartarugas marinhas pela pesca de espinhel pelágico no Nordeste do Brasil

The marine turtles biological characteristics and the impact they have been suffering in consequence of human activities have caused in the last decades the decrease of populations to unsustainable levels. All four of the species described in this paper are registered as endangered in a list by IUCN: Caretta caretta, Lepidochelys olivacea, Chelonia mydas, Dermochelys coriacea. The main causes of such impact include several fishing activities, mostly the surface longline. This paper discusses the monitoring of two foreigner longline fleet along the North East Brazilian coast between October of 2004 and September of 2005. Both operated in the West South Atlantic, one using the Chinese technique and the other the American. The American method s target species is the swordfish (Xiphias gladius), and it is characterized by using squid as bait, J 9/0 offset 5º hook, light sticks and night soaking. It also operates in shallower waters than the Chinese method. The source of information about the efforts and the catches came from onboard observers and were used to calculate the catching rate of turtles over 1000 hooks (CPUE). The American equipment caught more turtles (CPUE = 0,059; N= 103), mainly D. coriacea, while the Chinese longline caught mainly the L. olivacea and presented a CPUE= 0,018 (N= 89). The hooks were most frequently found attached to the mouth of C. caretta, C. mydas, and L. olivacea. The D. coriacea were most frequently caught by hooks externally attached to different parts of their body. There was no significant difference between the hook type catching and most turtles were still alive when released. The results suggest a greater potential of turtle catching by the American method. Besides the statistic tests have showed less interaction between the Chinese equipment and marine turtles, the catches of this fishing technique could have been underestimated due to miscommunication between the onboard observer and the vessel s crew plus the retrieve of the longline during night time

Caracterização da captura incidental de tartarugas marinhas pela pesca de espinhel pelágico no Nordeste do Brasil

The marine turtles biological characteristics and the impact they have been suffering in consequence of human activities have caused in the last decades the decrease of populations to unsustainable levels. All four of the species described in this paper are registered as endangered in a list by IUCN: Caretta caretta, Lepidochelys olivacea, Chelonia mydas, Dermochelys coriacea. The main causes of such impact include several fishing activities, mostly the surface longline. This paper discusses the monitoring of two foreigner longline fleet along the North East Brazilian coast between October of 2004 and September of 2005. Both operated in the West South Atlantic, one using the Chinese technique and the other the American. The American method s target species is the swordfish (Xiphias gladius), and it is characterized by using squid as bait, J 9/0 offset 5º hook, light sticks and night soaking. It also operates in shallower waters than the Chinese method. The source of information about the efforts and the catches came from onboard observers and were used to calculate the catching rate of turtles over 1000 hooks (CPUE). The American equipment caught more turtles (CPUE = 0,059; N= 103), mainly D. coriacea, while the Chinese longline caught mainly the L. olivacea and presented a CPUE= 0,018 (N= 89). The hooks were most frequently found attached to the mouth of C. caretta, C. mydas, and L. olivacea. The D. coriacea were most frequently caught by hooks externally attached to different parts of their body. There was no significant difference between the hook type catching and most turtles were still alive when released. The results suggest a greater potential of turtle catching by the American method. Besides the statistic tests have showed less interaction between the Chinese equipment and marine turtles, the catches of this fishing technique could have been underestimated due to miscommunication between the onboard observer and the vessel s crew plus the retrieve of the longline during night time

Chemical constituents of the volatile oil from leaves of Annona coriacea and in vitro antiprotozoal activity

The essential oil of the leaves from Annona coriacea Mart., Annonaceae, was extracted by hydrodistillation in a Clevenger apparatus and analyzed by GC/MS and GC/FID. The oil yield was 0.05% m/m. Sixty compounds were identified, in a complex mixture of sesquiterpenes (76.7%), monoterpenes (20.0%) and other constituents (3.3%). Bicyclogermacrene was its major compound (39.8%) followed by other sesquiterpenes. Most of the monoterpenes were in low concentration (<1%). Only β-pinene and pseudolimonene presented the highest level of 1.6%. The volatile oil presented anti-leishmanial and trypanocidal activity against promastigotes of four species of Leishmania and trypomastigotes of Trypanosoma cruzi, showing to be more active against Leishmania (L.) chagasi (IC50 39.93 µ g/mL) (95% CI 28.00-56.95 µ g/mL).