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/

Éditeur(s) : HAL CCSD
Résumé : International audience
With the health of the world’s oceans threatened as never before, it is becoming increasingly apparent that Marine Protected Areas (MPAs) play a vitally important role in protecting marine and coastal habitats. Management of Marine Protected Areas: A Network Perspective draws on the results of a major EU-sponsored research project related to the establishment of networks of MPAs in the Mediterranean and Black Seas that transpired from February 2011 to January 2016. Featuring contributions by leading university- and national research institute-based scientists, chapters utilize the latest research data and developments in marine conservation policy to explore issues related to ways in which networks of MPAs may amplify the effectiveness and conservation benefits of individual areas within them. Topics addressed include the broader socio-economic impacts of MPAs in the Mediterranean and Black Seas; the use of Marine Spatial Planning (MSP) to resolve conflicts between marine resource use and protection; special protection measures under the EU’s Marine Strategy Framework Directive (MSFD); ecological value assessments in the Black Sea; the Ecosystem Approach (EA) for managing marine ecosystems; MPAs along Turkey’s Black Sea coast; MPAs and offshore wind farms; and managing and monitoring MPA networks within and between the Black and Mediterranean Seas.Timely and important, Management of Marine Protected Areas: A Network Perspective offers invaluable insights into the role of MPAs in preserving the welfare and long-term viability of our world’s oceans.
Management of Marine Protected Areas: A Network Perspective

ISBN : 978-1-119-07577-6
hal-01562040
https://hal-univ-perp.archives-ouvertes.fr/hal-01562040

Éditeur(s) : IEEE
Résumé : It is now well understood that data on soil moisture and sea surface salinity (SSS) are required to improve meteorological and climate predictions. These two quantities are not yet available globally or with adequate temporal or spatial sampling. It is recognized that a spaceborne L-band radiometer with a suitable antenna is the most promising way of fulfilling this gap. With these scientific objectives and technical solution at the heart of a proposed mission concept the European Space Agency (ESA) selected the Soil Moisture and Ocean Salinity (SMOS) mission as its second Earth Explorer Opportunity Mission. The development of the SMOS mission was led by ESA in collaboration with the Centre National d'Etudes Spatiales (CNES) in France and the Centro para el Desarrollo Tecnologico Industrial (CDTI) in Spain. SMOS carries a single payload, an L-Band 2-D interferometric radiometer operating in the 1400-1427-MHz protected band [1]. The instrument receives the radiation emitted from Earth's surface, which can then be related to the moisture content in the first few centimeters of soil over land, and to salinity in the surface waters of the oceans. SMOS will achieve an unprecedented maximum spatial resolution of 50 km at L-band over land (43 km on average over the field of view), providing multiangular dual polarized (or fully polarized) brightness temperatures over the globe. SMOS has a revisit time of less than 3 days so as to retrieve soil moisture and ocean salinity data, meeting the mission's science objectives. The caveat in relation to its sampling requirements is that SMOS will have a somewhat reduced sensitivity when compared to conventional radiometers. The SMOS satellite was launched successfully on November 2, 2009.
Proceedings of the IEEE (0018-9219) (IEEE), 2010-05 , Vol. 98 , N. 5 , P. 666-687

Droits : 2010 IEEE – All Rights Reserved
http://archimer.ifremer.fr/doc/00004/11483/8065.pdf
DOI:10.1109/JPROC.2010.2043032
http://archimer.ifremer.fr/doc/00004/11483/

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
1. The use of targets to provide measurable objectives and benchmarks for management, conservation, andrestoration of ecosystems is commonplace. In the marine and coastal realms, targets have been successful insetting sustainable limits to fisheries harvests, thresholds for pollutants, and recommended amounts ofrepresentative habitat included in marine protected area (MPA) networks. Quantifiable targets can dissuadegovernments from making dubious claims about investments in ocean protection that sound impressive butcannot be verified. Examples are presented where protection targets have been used successfully for marinemanagement, and instances where measurable and meaningful benchmarks serve to allow tracking of true progress.2. However, the setting of targets can also be a double-edged sword. In some cases, targets have proven useful,but in many instances, interventions made to fulfil targets not only give a false illusion of progress or even success,they present opportunity costs that impede further conservation.3. Some of these issues were raised in the 2003 article ‘Dangerous Targets?: Unresolved issues and ideologicalclashes around marine protected areas’ that appeared in Aquatic Conservation: Marine and FreshwaterEcosystems. Since its publication, the article’s warnings about how targets can sometimes be dangerous andcounter-productive have led to intense debate among scientists and policy-makers alike, and the paper has beencited in more than 500 publications. Yet today, more than a dozen years after the first ‘Dangerous Targets’publication, new targets are driving more MPA designations and conservation strategies than ever before, andthe ‘dangerous’ aspects of target setting have been largely ignored.4. This paper discusses old ‘dangers’ in the context of new developments in marine conservation, including thelingering problem of having simplistic metrics drive marine policies, and the unintended result that can often occurwhen outputs (percentage of area under MPA designation) do not align with true outcomes of effectivemanagement and conservation. Newly emerging ‘dangers’ in letting areal targets (percentage of area underMPA designation) drive MPA designations are also discussed, including how the rush to fulfil obligations toprotect a certain proportion of area is taking place in planning, separate from broader level, and potentiallymore holistic, marine spatial planning (MSP).5. The paper suggests five recommendations that would allow policy-makers to use targets more effectively,including: (1) increase transparency in planning, especially around specific goals and objectives of MPAestablishment; (2) use time-based areal targets when representativity is a goal of the protected area strategy; (3)
ISSN: 1052-7613

hal-01380963
https://hal-univ-perp.archives-ouvertes.fr/hal-01380963
DOI : 10.1002/aqc.2675

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : This paper aims to explore the complex relationships between international tourism and the production and exchange of 'nature' in tropical countries. It is based on data gathered through an ethnographic case study approach on the changing aesthetic, economic and symbolic values attached to the coral reef in the tropical island of La Réunion, Indian Ocean. The analysis of this data shows that, from the point where the collective imaginaries in the Western world associate a 'magic' value with corals, an international institutionalisation process takes place in order to protect and preserve coral reefs and make them touristically accessible. This raises important issues related to the challenges the new value of tropical nature represents for the communication and exchange systems of communities in tropical countries. The paper first explores the meanings of the spiritual and religious value Western societies attribute to coral reefs. It then discusses the institutionalisation of tropical nature by international organisations and the problem of parallel land and natural space ownership systems in La Réunion. After that, it deconstructs the mystification policy of the coral reef operated by local institutions in La Réunion and examines the meaning of protecting the coral reef as a socially embedded 'communicative action' in La Réunion.
L’objectif de cette étude est d’explorer les relations complexes entre d'une part le tourisme international et d'autre part la production et l'échange de 'nature' dans des pays tropicaux. L'étude est basée sur des données recueillies à travers une approche ethnographique des valeurs esthétiques, économiques et symboliques attachées au récif corallien de l'île de La Réunion, dans l'océan Indien. L'analyse de ces données montre qu'à partir du moment où les imaginaires collectifs de l'Occident associent les coraux à une valeur 'magique', un processus d'institutionnalisation internationale s’engage dans le but de protéger, préserver et rendre accessibles au tourisme les récifs coralliens. Ceci implique des problématiques importantes liées à la mise à l'épreuve des systèmes de communication et d'échange des sociétés dans les pays tropicaux. L'étude explore d'abord la signification des valeurs spirituelles et religieuses qu'attribuent les sociétés occidentales aux récifs coralliens. Ensuite, elle discute l'institutionnalisation de la nature tropicale par des organisations internationales ainsi que le problème de l'existence de différents systèmes de gestion foncière à La Réunion. Enfin, l'étude déconstruit la politique de mythification du récif corallien mise en œuvre par des institutions locales à La Réunion et examinera la signification de 'protéger l'environnement' en tant qu'action communicante définie par les systèmes de communication et d'échange réunionnais.
Réunion

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.1112
http://journals.openedition.org/etudescaribeennes/1112

Éditeur(s) : HAL CCSD
Résumé : Coral reefs are amongst the richest and more emblematic ecosystems of the world. These hotspots of biodiversity provide many services to Human societies, bringing leisure and economic added values. In many areas, especially developing countries, these ecosystems are submitted to both climate change (rise of sea temperature and level, acidification) and human coastal pressures (urbanisation, resources exploitation). In this context, an increasing number of Marine Protected Areas is settled on coral reefs environments in order to ensure their conservation and to mitigate local pressures. Hence, one of MPAs Managers' missions is to bring ecological and social data together to build integrated indicators of effectiveness. In Reunion Island, a MPA called the Marine reserve of La Réunion was settled in 2007 along a densely urbanised and populated fringing reef coast. In order to better evaluate its MPA effectiveness, the manager requires the integration of social stakes to the management plan. A uses monitoring protocol was developed in this purpose using an ultra light aircraft and a camera. Data on 15 different recreational and non-recreational uses were acquired between 2010 and 2013, flying 48 times a year, and entered into a Geographic Information System. A huge resulting database allowed the building of an initial knowledge of the spatio-temporal distribution of uses within the Reserve. It also enabled the analysis of the uses' evolution regarding various factors of variations (amenities, facilities, shark attacks, tourism, etc.). Finally, we assessed the contribution to management efficiency using social indicators (governance, pressure indicators), and to interdisciplinary research in bringing ecologic and uses data together. This thesis brings a brand new information about coastal human activity and spatio-temporal dynamics of direct pressures on reef. This tool, designed to be reproducible and cost-optimized, enables the production of a set of indicators. Its integration to the management plan exclusively depends on the strategic choices of the manager.
Les récifs coralliens figurent parmi les biomes côtiers les plus emblématiques de la planète. Ces points chauds de la biodiversité mondiale sont convoités par les sociétés humaines pour leurs qualités paysagères et leur plus-value économique. Exposés au même titre que de nombreux écosystèmes côtiers aux changements climatiques (élévation de la température, acidification des océans), ils sont de toutes parts soumis à une anthropisation littorale mal maitrisée (urbanisation, surexploitation des ressources). Dans ce contexte, de plus en plus d' Aires Marines Protégées (AMP) s'établissent sur des écosystèmes anthropisés, les amenant à intégrer l'Homme au coeur de la gestion. À La Réunion où l'urbanisation littorale est dense et où le paysage des usages littoraux ne cesse de s’étoffer, une Réserve Naturelle Marine (RNMR) a été établie en 2007 sur un récif frangeant. L’évaluation de l’efficacité de cette AMP par son gestionnaire doit se faire par le biais d'un ensemble d'indicateurs écologiques et socio-économiques. C’est en vue d’apporter des connaissances sur la fréquentation et les usages pratiqués au sein de la RNMR que cette thèse a été initiée. Elaboré sur la base d'un suivi en ULM, un protocole a été reproduit chaque année entre 2010 et 2013 et a permis la constitution d'une base de données spatialisée, dont l'exploitation a produit trois types de résultats: i) une connaissance initiale de la répartition spatio-temporelle des usages au sein de la RNMR; ii) une compréhension de l'évolution des dynamiques spatio-temporelles à la lumière des facteurs de variations identifiés (aménagements, aménités, crise requin, tourisme, etc.), et iii) une contribution à la gestion par le développement d'indicateurs sociaux (gouvernance, pressions), et à la recherche interdisciplinaire par une confrontation des données de fréquentation et des données écologiques du milieu. La réflexion menée dans le cadre de cette thèse apporte un éclairage nouveau sur les usages et la fréquentation des littoraux coralliens à La Réunion, et leur traduction en termes de pression anthropique directe. Pensé pour être reproductible et optimisé en termes de coût, cet outil permet la production d’un ensemble d’indicateurs dont l’intégration au plan de gestion dépend exclusivement des choix stratégiques du gestionnaire.
https://tel.archives-ouvertes.fr/tel-01308703

Droits : http://creativecommons.org/licenses/by-nc-sa/
tel-01308703
https://tel.archives-ouvertes.fr/tel-01308703
https://tel.archives-ouvertes.fr/tel-01308703/document
https://tel.archives-ouvertes.fr/tel-01308703/file/Th%C3%A8se_Lemahieu.pdf

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Anthropogenic impacts are increasingly affecting the world's oceans. Networks of marine protected areas (MPAs) provide an option for increasing the ecological and economic benefits often provided by single MPAs. It is vital to empirically assess the effects of MPA networks and to prioritize the monitoring data necessary to explain those effects. We summarize the types of MPA networks based on their intended management outcomes and illustrate a framework for evaluating whether a connectivity network is providing an outcome greater than the sum of individual MPA effects. We use an analysis of an MPA network in Hawai'i to compare networked MPAs to non-networked MPAs to demonstrate results consistent with a network effect. We assert that planning processes for MPA networks should identify their intended outcomes while also employing coupled field monitoring-simulation modeling approaches, a powerful way to prioritize the most relevant monitoring data for empirically assessing MPA network performance.
ISSN: 1932-6203

Droits : http://creativecommons.org/licenses/by/
hal-01341695
https://hal-univ-perp.archives-ouvertes.fr/hal-01341695
https://hal-univ-perp.archives-ouvertes.fr/hal-01341695/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01341695/file/journal.pone.0102298.PDF
DOI : 10.1371/journal.pone.0102298

Éditeur(s) : Amer Meteorological Soc
Résumé : Salinity measurements from 119 surface drifters in 2007-12 were assessed; 80% [Surface Velocity Program with a barometer with a salinity sensor (SVP-BS)] and 75% [SVP with salinity (SVP-S)] of the salinity data were found to be usable, after editing out some spikes. Sudden salinity jumps are found in drifter salinity records that are not always associated with temperature jumps, in particular in the wet tropics. A method is proposed to decide whether and how to correct those jumps, and the uncertainty in the correction applied. Northeast of South America, in a region influenced by the Amazon plume and fresh coastal water, drifter salinity is very variable, but a comparison with data from the Soil Moisture and Ocean Salinity satellite suggests that this variability is usually reasonable. The drifter salinity accuracy is then explored based on comparisons with data from Argo floats and from thermosalinographs (TSGs) of ships of opportunity. SVP-S/SVP-BS drifter records do not usually present significant biases within the first 6 months, but afterward biases sometimes need to be corrected (altogether, 16% of the SVP-BS records). Biases start earlier after 3 months for drifters not protected by antifouling paint. For the few drifters for which large corrections were applied to portions of the record, the accuracy cannot be proven to be better than 0.1 psu, and it cannot be proven to be better than 0.5 psu for data in the largest variability area off northeast South America. Elsewhere, after excluding portions of the records with suspicious salinity jumps or when large corrections were applied, the comparisons rule out average biases in individual drifter salinity record larger than 0.02 psu (midlatitudes) and 0.05 psu (tropics).
Journal Of Atmospheric And Oceanic Technology (0739-0572) (Amer Meteorological Soc), 2014-04 , Vol. 31 , N. 4 , P. 967-983

Droits : 2014 American Meteorological Society
http://archimer.ifremer.fr/doc/00190/30095/28748.pdf
DOI:10.1175/JTECH-D-13-00158.1
http://archimer.ifremer.fr/doc/00190/30095/