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Auteur Dalleau, M.; Kramer-Schadt, S.; Gangat, Y.; Bourjea, J.; Lajoie, G.; Grimm, V.
Titre Modeling the emergence of migratory corridors and foraging hot spots of the green sea turtle Type Article scientifique
Année 2019 Publication Revue Abrégée Ecol. Evol.
Volume Numéro Pages
Mots-Clés aldabra atoll; chelonia-mydas; connectivity; corridors; individual-based model; leatherback turtles; marine turtles; migration; movement; penghu archipelago; population-dynamics; remigration intervals; satellite-tracking; sea turtle; wan-an island
Résumé Environmental factors shape the spatial distribution and dynamics of populations. Understanding how these factors interact with movement behavior is critical for efficient conservation, in particular for migratory species. Adult female green sea turtles, Chelonia mydas, migrate between foraging and nesting sites that are generally separated by thousands of kilometers. As an emblematic endangered species, green turtles have been intensively studied, with a focus on nesting, migration, and foraging. Nevertheless, few attempts integrated these behaviors and their trade-offs by considering the spatial configurations of foraging and nesting grounds as well as environmental heterogeneity like oceanic currents and food distribution. We developed an individual-based model to investigate the impact of local environmental conditions on emerging migratory corridors and reproductive output and to thereby identify conservation priority sites. The model integrates movement, nesting, and foraging behavior. Despite being largely conceptual, the model captured realistic movement patterns which confirm field studies. The spatial distribution of migratory corridors and foraging hot spots was mostly constrained by features of the regional landscape, such as nesting site locations, distribution of feeding patches, and oceanic currents. These constraints also explained the mixing patterns in regional forager communities. By implementing alternative decision strategies of the turtles, we found that foraging site fidelity and nesting investment, two characteristics of green turtles' biology, are favorable strategies under unpredictable environmental conditions affecting their habitats. Based on our results, we propose specific guidelines for the regional conservation of green turtles as well as future research suggestions advancing spatial ecology of sea turtles. Being implemented in an easy to learn open-source software, our model can coevolve with the collection and analysis of new data on energy budget and movement into a generic tool for sea turtle research and conservation. Our modeling approach could also be useful for supporting the conservation of other migratory marine animals.
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Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 2045-7758 ISBN Médium
Région Expédition Conférence
Notes WOS:000481747800001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2621
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Auteur Jensen, M.P.; FitzSimmons, N.N.; Bourjea, J.; Hamabata, T.; Reece, J.; Dutton, P.H.
Titre The evolutionary history and global phylogeography of the green turtle (Chelonia mydas) Type Article scientifique
Année 2019 Publication Revue Abrégée Journal of Biogeography
Volume 46 Numéro 5 Pages 860-870
Mots-Clés marine; mtDNA; conservation units; genetic hotspots; genetic structure; sea turtle
Résumé Aim To examine the genetic structure and global phylogeography of the endangered green sea turtle, Chelonia mydas, in light of past climatic events and current conservation needs. Location Tropical and subtropical beaches around the world. Methods We analysed 386 base pairs of the mitochondrial (mt)DNA control region of 4,878 individual nesting green turtle samples from 127 rookeries globally. We used phylogeographic analysis to assess how demographic history, dispersal and barriers to gene flow have led to the current distribution of mtDNA lineages. Results We identified 11 divergent lineages that were tied to specific biogeographical regions. The phylogenetic analyses revealed an ancient origin for the species centred in the Indo-Pacific and more recent colonization of the Central/Eastern Pacific as well as the Atlantic Basin. Overall the phylogeographic structure was strong but with a clear pattern of regional connectivity among rookeries. A Large genetic separation was found where there were obvious barriers to dispersal such as between the Atlantic and Pacific oceans and across the Pacific Ocean, as well as less obvious barriers to dispersal. Admixture of mtDNA haplotype lineages was detected at latitudinal extremes across the Indian Ocean and western Pacific Ocean resulting in these areas being nucleotide diversity hotspots. The highest regional genetic diversity and high endemic richness was observed in the SW Pacific, NW Pacific, SW Indian and NW Indian oceans. Main conclusions Past climatic fluctuations greatly affected the distribution of genetic diversity in the highly migratory green turtle. Our data suggest that past climatic events influenced local populations in different ways and the species appears to have survived the last glaciations in multiple glacial refugia.
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Editeur Lieu de Publication Éditeur
Langue en Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1365-2699 ISBN Médium
Région Expédition Conférence
Notes WOS:000471344900003 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2608
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Auteur Putman, N.F.; Abreu-Grobois, F.A.; Broderick, A.C.; Ciofi, C.; Formia, A.; Godley, B.J.; Stroud, S.; Pelembe, T.; Verley, P.; Williams, N.
Titre Numerical dispersal simulations and genetics help explain the origin of hawksbill sea turtles in Ascension Island Type Article scientifique
Année 2014 Publication Revue Abrégée Journal of Experimental Marine Biology and Ecology
Volume 450 Numéro Special Issue Pages 98-108
Mots-Clés dispersal; mtDNA; ocean circulation model; Sea turtle
Résumé Long-distance dispersal and ontogenetic shifts in habitat use are characteristic of numerous marine species and have important ecological, evolutionary, and management implications. These processes, however, are often challenging to study due to the vast areas involved. We used genetic markers and simulations of physical transport within an ocean circulation model to gain understanding into the origin ofjuvenile hawksbill sea turtles (Eretmochelys imbricata) found at Ascension Island, a foraging ground that is thousands of kilometers from known nesting beaches. Regional origin of genetic markers suggests that turtles are from Western Atlantic (86%) and Eastern Atlantic (14%) rookeries. In contrast, numerical simulations of transport by ocean currents suggest that passive dispersal from the western sources would be negligible and instead would primarily be from the East, involving rookeries along Western Africa (i.e., Principe Island) and, potentially, from as far as the Indian Ocean (e.g., Mayotte and the Seychelles). Given that genetic analysis identified the presence of a haplotype endemic to Brazilian hawksbill rookeries at Ascension, we examined the possible role of swimming behavior by juvenile hawksbills from NE Brazil on their current-borne transport to Ascension Island by performing numerical experiments in which swimming behavior was simulated for virtual particles (simulated turtles). We found that oriented swimming substantially influenced the distribution of particles, greatly altering the proportion of particles dispersing into the North Atlantic and South Atlantic. Assigning location-dependent orientation behavior to particles allowed them to reach Ascension Island, remain in favorable temperatures, encounter productive foraging areas, and return to the vicinity of their natal site. The age at first arrival to Ascension (4.5-5.5 years) of these particles corresponded well to estimates of hawksbill age based on their size. Our findings suggest that ocean currents and swimming behavior play an important role in the oceanic ecology of sea turtles and other marine animals.
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Langue Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0022-0981 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel LL @ pixluser @ collection 333
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Auteur Putman, N.F.; Verley, P.; Shay, T.J.; Lohmann, K.J.
Titre Simulating transoceanic migrations of young loggerhead sea turtles : merging magnetic navigation behavior with an ocean circulation model Type Article scientifique
Année 2012 Publication Revue Abrégée Journal of Experimental Biology
Volume 215 Numéro 11 Pages 1863-1870
Mots-Clés dispersal; Distribution; loggerhead sea turtle; magnetic map; magnetorecpetion; ocean circulation model
Résumé Young loggerhead sea turtles (Caretta caretta) from eastern Florida, USA, undertake a transoceanic migration in which they gradually circle the Sargasso Sea before returning to the North American coast. Loggerheads possess a. magnetic map' in which regional magnetic fields elicit changes in swimming direction along the migratory pathway. In some geographic areas, however, ocean currents move more rapidly than young turtles can swim. Thus, the degree to which turtles can control their migratory movements has remained unclear. In this study, the movements of young turtles were simulated within a high-resolution ocean circulation model using several different behavioral scenarios, including one in which turtles drifted passively and others in which turtles swam briefly in accordance with experimentally derived data on magnetic navigation. Results revealed that small amounts of oriented swimming in response to regional magnetic fields profoundly affected migratory routes and endpoints. Turtles that engaged in directed swimming for as little as 1-3 h per day were 43-187% more likely than passive drifters to reach the Azores, a productive foraging area frequented by Florida loggerheads. They were also more likely to remain within warm-water currents favorable for growth and survival, avoid areas on the perimeter of the migratory route where predation risk and thermal conditions pose threats, and successfully return to the open-sea migratory route if carried into coastal areas. These findings imply that even weakly swimming marine animals may be able to exert strong effects on their migratory trajectories and open-sea distributions through simple navigation responses and minimal swimming.
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Langue Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0022-0949 ISBN Médium
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Notes Approuvé pas de
Numéro d'Appel LL @ pixluser @ collection 215
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Auteur Rees, A.F.; Alfaro-Shigueto, J.; Barata, P.C.R.; Bjorndal, K.A.; Bolten, A.B.; Bourjea, J.; Broderick, A.C.; Campbell, L.M.; Cardona, L.; Carreras, C.; Casale, P.; Ceriani, S.A.; Dutton, P.H.; Eguchi, T.; Formia, A.; Fuentes, M.M.P.B.; Fuller, W.J.; Girondot, M.; Godfrey, M.H.; Hamann, M.; Hart, K.M.; Hays, G.C.; Hochscheid, S.; Kaska, Y.; Jensen, M.P.; Mangel, J.C.; Mortimer, J.A.; Naro-Maciel, E.; Ng, C.K.Y.; Nichols, W.J.; Phillott, A.D.; Reina, R.D.; Revuelta, O.; Schofield, G.; Seminoff, J.A.; Shanker, K.; Tomás, J.; van de Merwe, J.P.; Van Houtan, K.S.; Vander Zanden, H.B.; Wallace, B.P.; Wedemeyer-Strombel, K.R.; Work, T.M.; Godley, B.J.
Titre Are we working towards global research priorities for management and conservation of sea turtles? Type Article scientifique
Année 2016 Publication Endangered Species Research Revue Abrégée
Volume 31 Numéro Pages 337-382
Mots-Clés Sea turtle; Marine conservation; Evidence-based conservation; Systematic review; Research prioritisation
Résumé In 2010, an international group of 35 sea turtle researchers refined an initial list of more than 200 research questions into 20 metaquestions that were considered key for management and conservation of sea turtles. These were classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies. To obtain a picture of how research is being focused towards these key questions, we undertook a systematic review of the peer-reviewed literature (2014 and 2015) attributing papers to the original 20 questions. In total, we reviewed 605 articles in full and from these 355 (59%) were judged to substantively address the 20 key questions, with others focusing on basic science and monitoring. Progress to answering the 20 questions was not uniform, and there were biases regarding focal turtle species, geographic scope and publication outlet. Whilst it offers some meaningful indications as to effort, quantifying peer-reviewed literature output is obviously not the only, and possibly not the best, metric for understanding progress towards informing key conservation and management goals. Along with the literature review, an international group based on the original project consortium was assigned to critically summarise recent progress towards answering each of the 20 questions. We found that significant research is being expended towards global priorities for management and conservation of sea turtles. Although highly variable, there has been significant progress in all the key questions identified in 2010. Undertaking this critical review has highlighted that it may be timely to undertake one or more new prioritizing exercises. For this to have maximal benefit we make a range of recommendations for its execution. These include a far greater engagement with social sciences, widening the pool of contributors and focussing the questions, perhaps disaggregating ecology and conservation.
Adresse United States Geological Survey, National Wildlife Health Center, Honolulu Field Station, PO Box 50167, Honolulu, HI 96850, USA
Auteur institutionnel Thèse
Editeur Inter-Research Science Center Lieu de Publication Éditeur
Langue Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1863-5407 ISBN Médium
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Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ 47698 collection 1710
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