A Global strategy for the conservation of marine turtles Auteur(s) : IUCN/SSC Marine Turtle Specialist Group Éditeur(s) : IUCN--the World Conservation Union IUCN--the World Conservation Union ( Gland, Switzerland ) Résumé : (Statement of Responsibility) prepared by IUCN/SSC Marine Turtle Specialist Group. 34974457 97133999 2831702658 ocm34974457 http://ufdc.ufl.edu/AA00012420/00001 | Partager |
Diversité et différentiation génétiques des populations de tortues vertes (Chelonia mydas) dans les sites de ponte et d'alimentation du sud-ouest de l'océan Indien : application aux stratégies de conservation de l'espèce Auteur(s) : Taquet, Coralie Éditeur(s) : Université de la Réunion Résumé : The green turtle (Chelonia mydas) is an emblematic species of marine life. However, nowadays it is subject to many threats (poaching, by-catch). Even if there is deep growing measures for its protection, the green turtle still is an endangered species and it is listed in Appendix I of Washington Convention (CITES). In order to elaborate efficient conservation and management plans, perfect knowledge of green turtle biology, but also of its population structure and their characteristics, are needed. In this thesis, we have assessed genetic structure of green turtle populations in the South-Western Indian Ocean by using genetic tools. In all, 1551 tissue samples have been collected from our study zone and from our control site French Polynesia (37 samples). All kinds if individuals were sampled (except males in reproductive phase) from 15 sampling sites including nesting, foraging, and immature development site. We used both control region of mitochondrial DNA and 6 microsatellite loci to better infer maternal and paternal lineages. We identified 29 haplotypes in the South-Western Indian Ocean. They are distributed in 3 independent and highly divergent clades, including one composed with haplotypes from Atlantic Ocean. For 7 of these haplotypes, it was the first time they were detected in the study zone. Fifteen haplotypes were previously undescribed, distributed in all the 3 clades. These new haplotypes seem to be specific to the South-Western Indian Ocean, which is then an original zone. Besides, we found a high allelic richness. These results show the South-western Indian Ocean is rich and very diversified. This region plays an important role in the global diversity of the species. The South-Western Indian Ocean is one of the two contact zones presently known between the two metapopulations of green turtles (Atlantic-Mediterranean and Indo-Pacific). This contact induces a genetic cline based on CM8 (Atlantic) and C3 (Indo-Pacific) haplotype frequencies. Analysis of the microsatellite differentiation between individuals provides evidence of genetic exchanges between the two metapopulations in the region. The South-Western Indian Ocean participates to green turtle global genetic mixing. Studying the influence of several intrinsic and extrinsic factors on population structuring provides useful information for management plan elaboration. We found no significant difference between genetic structures of foraging females and males, contrary to immature turtles which seem to be organised in 'regional pools'. This organisation could be due to both immature natal homing and influence of oceanic currents. High mitochondrial differentiation of nesting females and low global microsatellite differentiation of our samples indicate male-mediated gene flow among populations of the study zone. The genetic composition of a sampling site presents no significant variation along the year, even if we could notice some trends. Nevertheless, it can be significantly different from a year to an other one. This may result from alternation of distinct populations on the same site. We noticed different evolution in 10 or 20 years of the genetic composition depending on the sampling site. Geographic distance seems not to have significant influence on population structuring concerning microsatellite markers. Nesting females of Saziley Beach (Mayotte Island, Comoros Archipelago) present genetic divergence from females nesting in the two other sampled beaches of this island. The observed population structure shows no contradiction with the organisation of oceanic currents in the South-Western Indian Ocean. Comparing the results from the two genetic markers used, we identified 8 genetic differentiated clusters of turtles in the study zone and at least 6 distinct populations. These clusters constitute 8 potential management units (MUs) which could serve as basis in the elaboration of conservation and management plans. La tortue verte (Chelonia mydas) constitue l'un des espèces emblématiques de la vie marine, pourtant de nombreuses menaces pèsent de nos jours encore sur sa survie (braconnage, captures accidentelles). Ainsi, malgré l'essor de mesures de protection menées à travers pour sa sauvegarde, la tortue verte constitue une espèce 'en danger d'extinction' et figure dans l'Annexe I de la Convention de Washington (CITES). Afin d'élaborer des plans de gestion et de conservation qui soient efficaces, il est important d'avoir une parfaite connaissance de la biologie de la tortue verte, mais aussi de la structure de ses populations et de leurs caractéristiques. C'est dans ce cadre que s'inscrit la présente étude. L'objectif de cette étude était d'acquérir des connaissances sur la structure des populations de tortues vertes dans le sud-ouest de l'océan Indien grâce à l'utilisation de l'outil génétique. Au total, 1551 échantillons de tissu ont été collectés dans la zone d'étude et dans notre site témoin la Polynésie française (37 échantillons). Toutes les catégories d'individus ont été échantillonnées (excepté les mâles en phase de reproduction) et les 15 sites d'échantillonnage comprennent à la fois des sites de ponte, d'alimentation et de développement pour les immatures. Deux types de marqueurs ont été utilisés : la région contrôle de l'ADN mitochondrial et 6 loci microsatellites, afin d'appréhender au mieux l'apport des lignées maternelles et paternelles. Nous avons pu mettre en évidence la présence dans le sud-ouest de l'océan Indien de 29 haplotypes distincts, appartenant à trois clades fortement divergents dont l'un constitué d'haplotypes originaires de l'océan Atlantique. Parmi ces haplotypes, 7 ont été détectés pour la première fois dans la zone d'étude, et 15 autres n'ont jamais été précédemment décrits chez cette espèce. Ils sont présents dans chacun des 3 clades d'haplotypes. Ces nouveaux haplotypes semblent spécifiques à la région, et en font une zone originale. On observe par ailleurs une grande richesse allélique dans les effectifs analysés. Ces résultats montrent que le sud-ouest de l'océan Indien est une zone riche et très diversifiée. Cette région joue un rôle important dans la diversité génétique globale de l'espèce. Le sud-ouest de l'océan Indien constitue l'une des deux seules zones connues à l'heure actuelle de contact entre les deux métapopulations de tortues vertes (Atlantique-Méditerranée et Indo-Pacifique). Ce contact a entraîné la formation d'un cline génétique portant principalement sur les fréquences relatives des haplotypes CM8 (Atlantique) et C3 (Indo-Pacifique). Les résultats obtenus lors de l'analyse microsatellite de la différenciation entre les individus originaires des deux métapopulations montrent que le sud-ouest de l'océan Indien constitue une zone d'échanges génétiques entre les deux métapopulations, participant au brasage génétique de l'espèce. L'étude de facteurs, intrinsèques et extrinsèques, pouvant influencer la structuration des populations apportent de nombreuses informations qui pourraient s'avérer utiles lors de l'élaboration de plans de gestion. La structure des femelles et des mâles en alimentation ne diffère pas, contrairement à celle des immatures qui semble s'organiser en 'pools régionaux' qui seraient le fruit de l'interaction d'un comportement de philopatrie et d'une influence des courants océaniques. La forte différenciation mitochondriale des femelles en ponte et la très faible différenciation microsatellite observée à l'échelle de la région, indiquent l'existence de flux de gènes via les mâles. La composition génétique d'un site ne varie pas de manière significative au cours de l'année. Par contre, elle peut varier d'une année à l'autre, signifiant l'alternance dans certains sites de ponte de plusieurs populations distinctes. L'évolution de la composition génétique d'un groupe, au cours de 10 ou 20 ans, diffère selon le site considéré. La distance ne semble pas influencer de manière significative la structuration des populations au niveau microsatellite. Les femelles en ponte sur la plage de Saziley (Mayotte) diffèrent génétiquement de celles pondant sur les deux autres plages de l'île. La structure observée des populations est en accord avec l'organisation des courants océanique dans la région. La confrontation des résultats obtenus à partir des deux marqueurs génétiques utilisés, permet la détermination de 8 ensembles génétiquement différenciés dans la zone d'étude et l'identification d'au moins 6 populations distinctes. Ces ensembles constituent autant d'unités de gestion (MUs) potentielles qui pourront servir de base à l'élaboration de plans de gestion et de conservation. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/2007/these-3532.pdf http://archimer.ifremer.fr/doc/00000/3532/ | Partager |
A man and a woman walk with a dog on a beach on Allen Cays, Exuma, Bahamas ; The Bryant Slides Collection ; The Bryant Slides Collection, Bahamas Auteur(s) : Unknown ( Photographer ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location. A man and a woman walk along a beach with a light colored, long haired dog. In the distance is a satellite and a green painted building, which may be part of the missile tracking station that was once located on Allen Cays, Exuma, Bahamas. During February of 1957, these two their companions travelled on the boat “Isabella” to many of the smaller islands of the Abacos, including Green Turtle Cay, Great Guana Cay, Allen Cay, and Grand Cay. Slide labeled Allen Cay Beach, Feb '57. Bahamas -- North America -- Allen Cays, Exuma Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@ucf.edu CFM1972_01a Sheet 3:3 http://ufdc.ufl.edu/AA00028361/00001 | Partager |
An Assessment of the status and exploitation of marine turtles in the UK overseas territories in the wider Caribbean Auteur(s) : Godley, B. J. Broderick, A. C. Campbell, L. M. Ranger, S. Richardson, P. B. Éditeur(s) : Marine Turtle Research Group, University of Exeter-Cornwall Department of Food, Environment, and Rural Affairs, United Kingdom Marine Turtle Research Group, University of Exeter-Cornwall Department of Food, Environment, and Rural Affairs, United Kingdom Résumé : This project was implemented by the Marine Turtle Research Group (University of Exeter in Cornwall, UK), the Marine Conservation Society (UK), and Duke University (USA) in association with the Cayman Islands Department of Environment, Cayman Turtle Farm, and University of Cardiff (UK). This initial consortium was expanded to include a large number of organisations across the Overseas Territories Droits : All rights reserved by the source institution. http://ufdc.ufl.edu/AA00012417/00001 | Partager Voir aussi |
Parliament Street, Green Turtle Cay, Abaco, Bahamas ; The Bryant Slides Collection ; The Bryant Slides Collection, Bahamas Nassau Hope Town Auteur(s) : Unknown ( Photographer ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location. Pictured is New Plymouth’s main street, Parliament Street, with signs that read “Barclays Bank D.C.O” and “Chester Lowe Groceries Bread.” Slide labeled New Plymouth '67. Bahamas -- North America -- New Plymouth, Green Turtle Cay, Abaco Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 19:16 http://ufdc.ufl.edu/AA00029578/00001 | Partager |
Oceanic survival and movements of wild and captive-reared immature green turtles (Chelonia mydas) in the Indian Ocean Auteur(s) : Pelletier, Dominique Roos, David Ciccione, Stéphane Éditeur(s) : Elsevier Résumé : The ability of captive-reared turtles to survive in the wild is not precisely known, nor are movements of immature turtles in the open ocean. To provide information on these issues, a satellite tracking experiment was conducted in the western Indian Ocean to monitor oceanic movements of immature green turtles. Two wild turtles and four captive-reared individuals were tracked. The latter had been displaced after birth from nesting sites to a distant rearing site. Wild turtles survived after release, but did not move far away from release site. We hypothesize that this resident behaviour may be explained by stage-specific habitat requirements. Captive-reared turtles survived after release and migrated over thousands of kilometres. Among these, the oldest immature turtles retrieved the foraging sites of their native population, with movement patterns similar to those displayed by adults. Observed movements may be linked to hydrographic conditions such as general oceanic circulation, sea temperature and thermal fronts. (C) 2003 Editions scientifiques et medicales Elsevier SAS and Ifremer/IRD/Inra/Cemagref. All rights reserved. Aquatic Living Resources (0990-7440) (Elsevier), 2003 , Vol. 16 , N. 1 , P. 35-41 Droits : 2003 Ifremer/IRD/Inra/Cemagref. Published by Elsevier, Paris http://archimer.ifremer.fr/doc/2003/publication-573.pdf DOI:10.1016/S0990-7440(03)00005-6 http://archimer.ifremer.fr/doc/00000/573/ | Partager Voir aussi Indian Ocean Captive reared Migration pattern Satellite telemetry Chelonia mydas Marine turtle Télécharger |
Four people and a dog walk on a path near houses in Great Guana Cay, Abaco, Bahamas ; The Bryant Slides Collection ; The Bryant Slides Collection, Bahamas Auteur(s) : Unknown ( Photographer ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location. Four people and a dog walk on a path near houses in Great Guana Cay, Abaco, Bahamas. A group of three people, wearing sunglasses, walk side by side toward the photographer. The group is made up of one man with a pipe in his mouth, a woman dressed in a white bathrobe, and another man who has a camera around his neck and wears a red shirt. In the distance, a person is bent over touching their pant leg while a dog approaches behind him or her. Another man can be seen sitting on a porch in one of the nearby houses. During February of 1957, this group of people travelled on the boat “Isabella” to many of the smaller islands of the Abacos, including Green Turtle Cay, Great Guana Cay, Allen Cay, and Grand Cay. Slide labeled Great Guiana Cay Feb '57. Bahamas -- North America -- Great Guana Cay, Abaco Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 9:20 http://ufdc.ufl.edu/AA00028710/00001 | Partager |
Four people walk on a beach on Great Guana Cay, Abaco, Bahamas ; The Bryant Slides Collection ; The Bryant Slides Collection, Bahamas Auteur(s) : Unknown ( Photographer ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location. Four people walk a beach on Great Guana Cay, Abaco, Bahamas. The group is made up of one man with a pipe in his mouth, a woman dressed in a white bathrobe, another man wearing a red shirt with the figure of a woman and plants, and another person wearing light colored pants and a long sleeve shirt. During February of 1957, this group of people travelled on the boat “Isabella” to many of the smaller islands of the Abacos, including Green Turtle Cay, Great Guana Cay, Allen Cay, and Grand Cay. Slide labeled Outer Beach Great Guiana Feb '57. Bahamas -- North America -- Great Guana Cay, Abaco Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 10:4 http://ufdc.ufl.edu/AA00028930/00001 | Partager |
Three Caucasian men view a boat under construction on Man of War Cay, Abaco, Bahamas ; The Bryant Slides Collection ; The Bryant Slides Collection, Bahamas Auteur(s) : Unknown ( Photographer ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location. The Abacos in the Bahamas are known for their tradition of building boats by hand with Man of War Cay being known as Abacos’ boat-building center. The Abacos’ crest also features a sail boat. This image features palm thatch roofed pavilions. Under one of the pavilions, three men view a boat under construction. The ground is covered with wood shavings and piles of wood. During February of 1957, this group of people travelled on the boat “Isabella” to many of the smaller islands of the Abacos, including Green Turtle Cay, Great Guana Cay, Allen Cay, and Grand Cay. Slide labeled Manowar Feb '57. Bahamas -- North America -- Man of War Cay, Abaco Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 5:5 http://ufdc.ufl.edu/AA00028436/00001 | Partager |
Mayotte Island: another important green turtle nesting site in the southwest Indian Ocean Auteur(s) : Bourjea, Jerome Frappier, Julie Quillard, Mireille Ciccione, Stephane Roos, David Hughes, Georges Grizel, Henri Éditeur(s) : Inter-Research Résumé : Situated in the north of the Mozambique Channel, Mayotte is the easternmost island of the Comoros Archipelago. From 1998 to 2005, Grande Saziley beach was monitored daily for green turtle Chelonia mydas nesting activity. Track surveys were monitored daily on 5 other adjacent beaches. Although nesting occurs throughout the year, nesting seasonality begins at the end of the wet season and intensifies during the dry season to reach an average nesting peak in June. In order to estimate the number of females nesting in the Saziley site and population trends over the study period, incubation success and number of nests per female and per season were estimated at 0.77 (±0.05 SD) and 3.03 (±0.37) respectively. With an average of 1545 nesting turtles per year (±439), the change in nesting numbers over the study period was so small that the population can be regarded as stable, with an estimated annual mean growth rate of 0.912, confirmation that this population is both stable and in good health. Added support for this argument is demonstrated by the fact that the annual carapace size distribution of nesting females is stable, meaning that the nesting green turtle population of Mayotte is not ageing or rejuvenating. After due consideration of data on other nesting sites in the southwest Indian Ocean, the data from Mayotte emphasizes the fact that the green turtle is not an endangered species in this region. Even if it is still illegally exploited and alterations occur in their different habitats, the green turtle populations of this region seem to have successfully survived all threats during the past century. Endangered Species Research (1613-4796) (Inter-Research), 2007-10-10 , Vol. 3 , P. 273-282 Droits : 2007 Inter-Research http://archimer.ifremer.fr/doc/00018/12916/9873.pdf DOI:10.3354/esr00053 http://archimer.ifremer.fr/doc/00018/12916/ | Partager |
Regional Management Units for Marine Turtles: A Novel Framework for Prioritizing Conservation and Research across Multiple Scales Auteur(s) : Wallace, Bryan P. Dimatteo, Andrew D. Hurley, Brendan J. Finkbeiner, Elena M. Bolten, Alan B. Chaloupka, Milani Y. Hutchinson, Brian J. Alberto Abreu-grobois, F. Éditeur(s) : Public Library Science Résumé : Background: Resolving threats to widely distributed marine megafauna requires definition of the geographic distributions of both the threats as well as the population unit(s) of interest. In turn, because individual threats can operate on varying spatial scales, their impacts can affect different segments of a population of the same species. Therefore, integration of multiple tools and techniques - including site-based monitoring, genetic analyses, mark-recapture studies and telemetry - can facilitate robust definitions of population segments at multiple biological and spatial scales to address different management and research challenges. Methodology/Principal Findings: To address these issues for marine turtles, we collated all available studies on marine turtle biogeography, including nesting sites, population abundances and trends, population genetics, and satellite telemetry. We georeferenced this information to generate separate layers for nesting sites, genetic stocks, and core distributions of population segments of all marine turtle species. We then spatially integrated this information from fine-to coarse-spatial scales to develop nested envelope models, or Regional Management Units (RMUs), for marine turtles globally. Conclusions/Significance: The RMU framework is a solution to the challenge of how to organize marine turtles into units of protection above the level of nesting populations, but below the level of species, within regional entities that might be on independent evolutionary trajectories. Among many potential applications, RMUs provide a framework for identifying data gaps, assessing high diversity areas for multiple species and genetic stocks, and evaluating conservation status of marine turtles. Furthermore, RMUs allow for identification of geographic barriers to gene flow, and can provide valuable guidance to marine spatial planning initiatives that integrate spatial distributions of protected species and human activities. In addition, the RMU framework - including maps and supporting metadata - will be an iterative, user-driven tool made publicly available in an online application for comments, improvements, download and analysis. Plos One (1932-6203) (Public Library Science), 2010-12 , Vol. 5 , N. 12 , P. - Droits : 2010 Plos One http://archimer.ifremer.fr/doc/00028/13926/11308.pdf DOI:10.1371/journal.pone.0015465 http://archimer.ifremer.fr/doc/00028/13926/ | Partager |
Five men and some steel drums are on a dock near a boat on Walker’s Cay, Abaco, Bahamas ; The Bryant Slides Collection ; The Bryant Slides Collection, Bahamas Auteur(s) : Unknown ( Photographer ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location. Walker’s Cay, located near a barrier reef, is the northern most island in the Bahamas. This image features the boat “Isabella” as it is anchored near a dock. The "Isabella" belonged to John Richard Yeend, also known as Captain Jack R. Yeend. During February of 1957, “Isabella” travelled to many of the smaller islands of the Abacos including Green Turtle Cay, Great Guana Cay, Allen Cay, and Grand Cay. A man is standing on the boat. On the dock are five men and some steel drums. Slide labeled Wharf Walker Cay Feb '57. Bahamas -- North America -- Walker's Cay, Abaco Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 5:20 http://ufdc.ufl.edu/AA00028454/00001 | Partager |
Influence de la temperature sur la differentiation sexuelle des gonades chez la tortue luth (Dermochelys coriacea ); etude en incubation artificielle et naturelle Auteur(s) : Rimblot, F Fretey, J Lescure, J Pieau, C Éditeur(s) : Actes de colloques. Ifremer. Brest [ACTES COLLOQ. IFREMER.]. 1985 Résumé : Sexual differentiation of the marine leatherback turtle is sensitive to temperature. Incubation of eggs below 29 degree C results in 100% males, whereas incubationa bove 30 degree C results in 100% potential females at hatching. Therefore, the threshold temperature lies between 29 and 30 degree C as has been found for other marine turtles (Caretta caretta, Chelonia mydas ). Among hatchlings from natural nests in French Guiana, 10% were males, 20% were potential females and 70% had an intermediate phenotype. The sand temperature at 60 cm of depth, near one nest, was recorded and was found to vary between 29 and 30 degree C during the presumed thermosensitive period. These results will be useful to marine turtle hatcheries which seek to manipulate sex ratios among their neonates. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/1983/acte-1241.pdf http://archimer.ifremer.fr/doc/00000/1241/ | Partager |
Global Conservation Priorities for Marine Turtles Auteur(s) : Wallace, Bryan P. Dimatteo, Andrew D. Bolten, Alan B. Chaloupka, Milani Y. Hutchinson, Brian J. Abreu-grobois, F. Alberto Mortimer, Jeanne A. Seminoff, Jeffrey A. Éditeur(s) : Public Library Science Résumé : Where conservation resources are limited and conservation targets are diverse, robust yet flexible priority-setting frameworks are vital. Priority-setting is especially important for geographically widespread species with distinct populations subject to multiple threats that operate on different spatial and temporal scales. Marine turtles are widely distributed and exhibit intra-specific variations in population sizes and trends, as well as reproduction and morphology. However, current global extinction risk assessment frameworks do not assess conservation status of spatially and biologically distinct marine turtle Regional Management Units (RMUs), and thus do not capture variations in population trends, impacts of threats, or necessary conservation actions across individual populations. To address this issue, we developed a new assessment framework that allowed us to evaluate, compare and organize marine turtle RMUs according to status and threats criteria. Because conservation priorities can vary widely (i.e. from avoiding imminent extinction to maintaining long-term monitoring efforts) we developed a "conservation priorities portfolio" system using categories of paired risk and threats scores for all RMUs (n = 58). We performed these assessments and rankings globally, by species, by ocean basin, and by recognized geopolitical bodies to identify patterns in risk, threats, and data gaps at different scales. This process resulted in characterization of risk and threats to all marine turtle RMUs, including identification of the world's 11 most endangered marine turtle RMUs based on highest risk and threats scores. This system also highlighted important gaps in available information that is crucial for accurate conservation assessments. Overall, this priority-setting framework can provide guidance for research and conservation priorities at multiple relevant scales, and should serve as a model for conservation status assessments and priority-setting for widespread, long-lived taxa. Plos One (1932-6203) (Public Library Science), 2011-09 , Vol. 6 , N. 9 , P. 1-14 Droits : 2011 Wallace et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License http://archimer.ifremer.fr/doc/00050/16097/13573.pdf DOI:10.1371/journal.pone.0024510 http://archimer.ifremer.fr/doc/00050/16097/ | Partager |
Marine Turtles, Ecosystem Services and Human Welfare in the Marine Ecosystems of the Caribbean Sea: A Discussion of Key Methodologies Auteur(s) : S. Teelucksingh, Sonja Eckert, Scott A.L.D. Nunes, Paulo Éditeur(s) : Université des Antilles Études caribéennes Résumé : It is increasingly recognized that maintaining biodiversity is of fundamental importance toward sustaining human livelihoods. One of the major assets of the region identified as “Latin America and the Caribbean” (LAC) is its biological wealth; by extension, the continued biodiversity loss of the LAC region is seen as one of the world’s principal environmental problems. The marine resources of Caribbean Sea are of vital economic, ecological and social importance to the LAC region, and are under particular threat. Marine turtles play vital roles throughout the Caribbean Sea both in terms of ecological functions and human welfare. Conservation efforts in this direction can often depend on the ability to place a value on welfare changes associated with the loss of ecosystem goods and services into which biodiversity plays an integral role.Using the ecosystem service categories of the Millennium Ecosystem Assessment, this paper discusses from an inter-disciplinary perspective the methodologies associated with linking marine turtles, ecosystem services and human welfare. While the main economic benefit to be currently valued may stem from the eco-tourism potential surrounding turtle nesting sites, for a true picture of the environmental resources upon which this service depends, it is necessary to also identify the other provisioning, regulating and cultural services of the resource. In this way, human welfare impacts can be more truly judged, and effective resource management can be undertaken. La préservation de la biodiversité est d'une importance fondamentale pour le maintien des moyens de subsistance de l'homme. L'un des atouts majeurs de l’ensemble régional que constitue l'Amérique latine et les Caraïbes (LAC) demeure sa richesse biologique, par extension, toute dégradation de sa biodiversité pose des problèmes environnementaux d’ordre mondial. Les ressources marines de la mer des Caraïbes, qui sont particulièrement menacées, sont d'une importance économique, écologique et sociale vitale pour la région. Les tortues marines jouent un rôle essentiel dans la mer des Caraïbes à la fois en termes de fonctions écologiques et de bien-être humain.En ce sens, les efforts de conservation peuvent de la capacité de chiffrer la valeur sur le bien-être des changements associés à la perte de biens et de services des écosystèmes dans lesquels la biodiversité est partie intégrante. En utilisant les catégories de services des écosystèmes du Millennium Ecosystem Assessment, la présente étude aborde, dans une perspective interdisciplinaire, les méthodologies associées aux interrelations entre les tortues marines, les services écosystémiques et le bien-être de l'homme.Si le principal avantage économique actuellement identifié repose sur le potentiel écotouristique, autour des sites de nidification des tortues, pour une image fidèle des ressources environnementales sur lesquelles ce service repose, il est nécessaire d'identifier également les autres apports de la ressource, en termes de régulations, de services culturels. De cette façon, les impacts sur le bien-être humain peuvent être mieux appréhendés et les ressources peuvent être gérées de façon plus efficace. Caraïbes Droits : info:eu-repo/semantics/openAccess urn:doi:10.4000/etudescaribeennes.10990 http://journals.openedition.org/etudescaribeennes/10990 | Partager |
Two men walk along the beach on Grand Cay, Abaco, Bahamas ; The Bryant Slides Collection ; The Bryant Slides Collection, Bahamas Auteur(s) : Unknown ( Photographer ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location. Two men walk along the beach on Grand Cay, Abaco, Bahamas. One of the men is holding a bonefish and the other man is holding a fishing rod. One of these men is John Richard Yeend. John Yeend, also known as Captain Jack R. Yeend, was the captain of the boat "Isabella." Originally from Ohio, Yeend moved with his wife Florence Mildred Snively to West Palm Beach, Florida in the 1960s. During February of 1957, “Isabella” travelled to many of the smaller islands of the Abacos including Green Turtle Cay, Great Guana Cay, Allen Cay, and Grand Cay. Slide labeled Grand Cays Bone Fish Feb '57 Jack Yeend Capt Isabella. Bahamas -- North America -- Grand Cay, Abaco Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 10:9 http://ufdc.ufl.edu/AA00028935/00001 | Partager |
Reproductive seasonality and trend of Chelonia mydas in the SW Indian Ocean: a 20 yr study based on track counts Auteur(s) : Lauret-stepler, Marie Bourjea, Jerome Roos, David Pelletier, Dominique Ryan, P.g. Ciccione, Stephane Grizel, Henri Éditeur(s) : Inter-Research Résumé : The green turtle Chelonia mydas is classified as endangered because of global declines over the past few centuries due to human exploitation and habitat destruction, particularly the loss of nesting areas. We used the number of tracks as an indicator of breeding female abundance at their nesting sites to study the seasonality and trends of turtles breeding at 3 islands in the SW Indian Ocean: Europa, Tromelin and Grande Glorieuse, over 20 yr. On Tromelin, tracks were counted along the entire nesting beach, but on Europa and Grande Glorieuse counts were limited to a proportion of the island. Europa and Tromelin exhibited similar seasonal patterns, with a well-defined peak during the wet season (November–February), compared to a dry season peak for Grande Glorieuse (March–June). The main season was significantly longer on Grande Glorieuse (288 ± 43 d) than on Europa (218 ± 60 d), with Tromelin intermediate (252 ± 43 d). There was greater variation in the start of a season compared to the median and end at all sites throughout the study. Approximately 7178 ± 3053 (n = 19) tracks were recorded annually on the entire nesting beach on Tromelin, compared with 1480 ± 666 (n = 19) on 16% of nesting beaches on Grande Glorieuse and 1361 ± 903 (n = 23) on 26% of beaches on Europa. The number of tracks has increased significantly on Europa (3% yr–1) and Grande Glorieuse (6% yr–1). The increasing number of nesting turtles illustrates the effectiveness of conservation measures on sites formerly exploited by humans. Endangered Species Research (1613-4796) (Inter-Research), 2007-08-15 , Vol. 3 , P. 217-227 Droits : 2007 Inter-Research http://archimer.ifremer.fr/doc/00018/12917/9874.pdf DOI:10.3354/esr003217 http://archimer.ifremer.fr/doc/00018/12917/ | Partager |
Estimation du nombre de tortues vertes femelles adultes Chelonia mydas par saison de ponte à Tromelin et Europa (Océan Indien) (1973-1985) Auteur(s) : Le Gall, Jean-yves Bosc, Pierre Taquet, Marc Éditeur(s) : Editions de l'ORSTOM Résumé : A research programm on the marine green turtle Chelonia mydas nesting on the two major reproduction sites for the species in the Indian Ocean, conducled over last 15 years, included intensive tagging programm. Processing of these lagging data provides estimations of adult female populations {or each site and season from two independent methods. First classical method is the ratio of total number of nests produced over a define time on the mean individual number of nests by female during the same time (November, December, January). The computed mean individual number ranges from 3 to 3.5 obtained over 2 to 3 months. The second method is the multiple capture-recapture method (JOLLY, 1965; SEBER, 1965; MANLY, 1984). Il is an original tentative of applying this method for the daily estimation of females number on a nesting site. The results obtained suggest this method to be applied for the species on other sites and to other marine turtle species. Population estimates obtained by these two independent methods are coherent Roughly, the two populations through seasonal nesting activity appear in wealthy state with a mean estimation number of 850 to 1100 females for Tromelin and more variable eslimations ranging from 2000 lo 11 000 females by season for Europa, considering lhe three major nesting months: November to January Un programme d'observations sur les populations de tortue verte marine Chelonia mydas pondant sur les deux sites de ponte majeurs de l'espèce dans l'océan Indien, Tromelin et Europa, comportait notamment un programme intensif de marquage. L'exploitation de ces données de marquage a permis de réaliser des estimations du nombre de femelles pondant sur chaque site par deux méthodes différentes. La première méthode est celle, classiquement utilisée, du rapport entre le nombre total de pontes déposées pour une période donnée et le nombre moyen de pontes par femelle durant le même temps. On démontre que le nombre moyen individuel de ponte est de l'ordre de 3 à 3,5 pontes par saison. La deuxième méthode est celle des estimations par marquages-recaptures multiples (J OLL Y -SEBER, 1965; MANLY, 1984). C'est une utilisation originale de cette méthode pour l'estimation journalière des populations de tortues femelles sur un site de ponte, qui doit pouvoir être appliquée sur d'autres sites pour la même espèce et pour d'autres espèces de tortues marines. Les résultats obtenus par ces deux méthodes différentes sont cohérents. Schématiquement, on peut conclure à deux populations abondantes de 850 à 1 ZOO femelles sur Tromelin par saison et des estimations moyennes variant de 2 000 à Il 000 tortues par saison pour l'ensemble des plages d'Europa pour les trois mois principaux de ponte par saison: novembre à janvier. Océanographie tropicale (0245-9418) (Editions de l'ORSTOM), 1986 , Vol. 21 , N. 1 , P. 3-22 Droits : ORSTOM http://archimer.ifremer.fr/doc/00113/22406/20103.pdf http://archimer.ifremer.fr/doc/00113/22406/ | Partager Voir aussi Tortue verte Chelonia mydas Reproduckion Ponte Population Femelles Marquage recapture Océan Indien. Marine green turtle Télécharger |
Marine turtle interaction with purse-seine fishery in the Atlantic and Indian oceans: Lessons for management Auteur(s) : Bourjea, Jerome Clermont, Sandra Delgado, Alicia Murua, Hilario Ruiz, Jon Ciccione, Stephane Chavance, Pierre Éditeur(s) : Elsevier Sci Ltd Résumé : Bycatch of endangered marine turtles is a growing issue for the management of all fisheries, including the oceanic purse-seine fishery. The aim of this study was to assess the spatial and temporal variation in bycatch rates of these species in the entire European purse-seine fishery operating in the Atlantic and Indian oceans. The study was based on data collected through observer programs from 1995 to 2011. During that period, a total of 15 913 fishing sets were observed, including 6 515 on Drifting Fish Aggregating Devices (DFADs) and 9 398 on free swimming schools, representing a global coverage of 10.3% and 5.1% of the total fishing activity in the Atlantic and Indian Ocean, respectively. Moreover, from 2003 to 2011, 14 124 specific observations were carried out on DFADs to check turtle entanglement in the net covering DFADs. We found that the purse-seine fishery has a very low impact on marine turtles. We estimated that the annual number of individuals incidentally captured was 218 (SD = 150) and 250 (SD = 157) in the Atlantic and Indian Ocean, respectively, with more than 75% being released alive. The present study also investigated the impact of DFADs; which is considered a key conservation issue for this fishery. Drifting objects may play a key role in aggregating juveniles of marine turtles, implying the need for improving their construction to avoid entanglement (e.g. avoiding nets in the structure); however, based on our study it is not the main source of incidental captures of marine turtles in this fishery. Biological Conservation (0006-3207) (Elsevier Sci Ltd), 2014-10 , Vol. 178 , P. 74-87 Droits : 2014 Elsevier Ltd. All rights reserved http://archimer.ifremer.fr/doc/00206/31760/30632.pdf DOI:10.1016/j.biocon.2014.06.020 http://archimer.ifremer.fr/doc/00206/31760/ | Partager |