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| Registros recuperados: 18 | |
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| Bourjea, Jerome; Dalleau, Mayeul; Jean, Claire; Ciccione, Stephane. |
| Dans la suite de la mission à Europa en 2011, des missions menées depuis 2005 par les équipes d’Ifremer et de Kélonia, et dans le cadre de l’Action 4.2.3 du Plan National d’Action (PNA) tortues marines dans les îles Eparses, l’objectif de cette mission à Glorieuses et à Juan de Nova a été de continuer à acquérir des données sur la dynamique spatio-temporelle des immatures de tortues vertes présentes dans les îles Eparses. Plus précisément, cette mission a eu pour objectif de : 1- continuer la série longue de marquage –relecture de tortues vertes juvéniles présentes dans le lagon des Glorieuses et de Juan de Nova ainsi que les suivis de croissance des individus recapturés, 2- déterminer le comportement spatial à fine échelle des tortues vertes juvéniles... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00260/37095/35605.pdf |
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| Clermont, Sandra; Chavance, Pierre; Delgado De Molina, Alicia; Murua, Hilario; Ruiz, Jon; Ciccione, Stephane; Bourjea, Jerome. |
| Bycatch of marine turtles, vulnerable or endangered species, is a growing issue of all fisheries, including Oceanic purse-seine fishery. The present paper seeks to assess marine turtle bycatch at a spatial and temporal level in the European purse seine fishery operating in the Atlantic and Indian Oceans. The study was based on data collected through French and Spanish observer programs from 1995 to 2011, a period where more than 230 000 fishing sets were realized by the UE fleets in both Oceans. A total of 15 913 fishing sets were observed, including 6 515 on drifting Fish Aggregate Devices (FAD) and 9 398 on Free Swimming Schools (FSC). Over the study period, 597 turtles were caught, 86% being released alive at sea. At the same time, from 2003 to 2011, 14... |
| Tipo: Text |
Palavras-chave: European tuna fishery; Purse seine; Marine turtle; Bycatch; Atlantic and Indian Oceans. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00149/25991/24087.pdf |
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| Bourjea, Jerome; Mouquet, Pascal; Quod, Jean-pascal; Ciccione, Stephane. |
| This report shows the sum up of a pluridisciplinary field trip done in May 2010 in Europa and Juan de Nova, 2 French islands that are part of the French Eparses Islands in the south west Indian Ocean. The objectives of this field trip were to: - Sample 3 coral fish species (L. kasmira, E. merra et M. berndti) in the framework of a project aiming to understand the marine life connectivity between Marine Protected Areas of the South West Indian Ocean. This field trip allowed sampling more than 150 specimens of these 3 species as well as others fish samples for ongoing genetic studies within the region. - Realise the ground truth after acquisition of bathymetric Lidar and Hyperspectral data within the project of reef habitats mapping of the South West Indian... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00018/12915/9872.pdf |
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| Ballorain, Katia; Ciccione, Stephane; Bourjea, Jerome; Grizel, Henri; Enstipp, Manfred; Georges, Jean-yves. |
| We investigated the habitat use in green turtles exploiting a 13-ha multispecific seagrass meadow at Mayotte Island, south-western Indian Ocean. A phytoecological survey shows the occurrence of eight seagrass species, dominated by Halodule uninervis and Syringodium isoetifolium, distributed according to four distinct seagrass communities along the depth gradient. Direct underwater censuses show that green turtles occurred all over the meadow. Yet when community relative surface area was taken into account green turtles preferentially frequented the most seaward, biomass-richer S. isoetifolium-dominated community, suggesting that green turtles compensate for their intrinsically nutrient-poor herbivorous diet. Additionally, smaller (\80 cm standard curved... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00018/12918/10201.pdf |
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| Bousquet, Olivier; Barruol, Guilhem; Cordier, Emmanuel; Barthe, Christelle; Bielli, Soline; Calmer, Radiance; Rindraharisaona, Elisa; Roberts, Gregory; Tulet, Pierre; Amelie, Vincent; Fleischer-dogley, Frauke; Mavume, Alberto; Zucule, Jonas; Zakariasy, Lova; Razafindradina, Bruno; Bonnardot, François; Singh, Manvendra; Lees, Edouard; Durand, Jonathan; Mekies, Dominique; Claeys, Marine; Pianezze, Joris; Thompson, Callum; Tsai, Chia-lun; Husson, Romain; Mouche, Alexis; Ciccione, Stephane; Cattiaux, Julien; Chauvin, Fabrice; Marquestaut, Nicolas. |
| The international research program “ReNovRisk-CYCLONE” (RNR-CYC, 2017–2021) directly involves 20 partners from 5 countries of the south-west Indian-Ocean. It aims at improving the observation and modelling of tropical cyclones in the south-west Indian Ocean, as well as to foster regional cooperation and improve public policies adapted to present and future tropical cyclones risk in this cyclonic basin. This paper describes the structure and main objectives of this ambitious research project, with emphasis on its observing components, which allowed integrating numbers of innovative atmospheric and oceanic observations (sea-turtle borne and seismic data, unmanned airborne system, ocean gliders), as well as combining standard and original methods... |
| Tipo: Text |
Palavras-chave: Tropical cyclone; South-west Indian Ocean; Gliders; Unmanned airborne system; Biologging; Sea turtles; Global satellite navigation system; ReNovRisk; Numerical modelling; Climate modelling; Austral and cyclonic swells; Seismic data. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00691/80281/83366.pdf |
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| Derville, Solene; Jean, Claire; Dalleau, Mayeul; Le Gal, Jean-yves; Ciccione, Stephane; Bourjea, Jerome. |
| Situated about 500 km off the Malagasy east coast, the island of Tromelin is a key nesting site for the endangered green turtle, Chelonia mydas, in the south Western Indian Ocean. Nesting turtles found in this isolated island have been closely monitored since the 1970s, but the most recent estimates of nesting parameters date from 1986. Using mark-recapture data, track counts, and nests monitoring data collected over the 2009/2010 nesting peak, reproductive characteristics, population size, and offspring production were updated and discussed in the light of the track survey undertaken from 1986 to 2010. Females showed a consistent reproductive behaviour compared with previous studies in terms of clutch frequency (2.75 +/- 1.46) and nesting success (0.65).... |
| Tipo: Text |
Palavras-chave: Reptilia Testudines: Cheloniidae Chelonia mydas; Green turtle nesting activity population assessment Indian Ocean Tromelin Island. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00273/38424/36794.pdf |
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| Bourjea, Jerome; Clermont, Sandra; Delgado, Alicia; Murua, Hilario; Ruiz, Jon; Ciccione, Stephane; Chavance, Pierre. |
| 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... |
| Tipo: Text |
Palavras-chave: Bycatch; Marine turtle; Fishery impacts; Fishery management; Atlantic Ocean; Indian Ocean. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00206/31760/30632.pdf |
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| Bourjea, Jerome; Frappier, Julie; Quillard, Mireille; Ciccione, Stephane; Roos, David; Hughes, Georges; Grizel, Henri. |
| 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... |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00018/12916/9873.pdf |
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| Bourjea, Jerome; Gravier-bonnet, Nicky; Boullet, Vincent; Ciccione, Stephane; Rolland, Robin. |
| Les objectifs de la mission était les suivants: - PROGRAMME TORTUES MARINES : (i) Collecte d’échantillons génétiques sur les juvéniles de tortue verte (Chelonia mydas) et imbriquée (d’Eretmochelys imbricata) dans la mangrove d’Europa (Programme Ifremer/Kelonia) ; (ii) Inventaire des habitats dans le lagon d’Europa et de Bassas da India - PROGRAMME VEGETAUX : (i) Inventaire de la flore vasculaire ; (ii) étude de la végétation d’Europa (Programme CBNM) - PROGRAMME HYDRAIRES : (i) Inventaire des hydraires présents à Europa ; (ii) Prospection sur Bassas Da India - Réalisation d’un documentaire de 26 minutes présentant les programmes de cette mission. |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00244/35519/34024.pdf |
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| Dalleau, Mayeul; Ciccione, Stephane; Mortimer, Jeanne A.; Garnier, Julie; Benhamou, Simon; Bourjea, Jerome. |
| Changes in phenology, the timing of seasonal activities, are among the most frequently observed responses to environmental disturbances and in marine species are known to occur in response to climate changes that directly affects ocean temperature, biogeochemical composition and sea level. We examined nesting seasonality data from long-term studies at 8 green turtle (Chelonia mydas) rookeries that include 21 specific nesting sites in the South-West Indian Ocean (SWIO). We demonstrated that temperature drives patterns of nesting seasonality at the regional scale. We found a significant correlation between mean annual Sea Surface Temperature (SST) and dates of peak nesting with rookeries exposed to higher SST having a delayed nesting peak. This supports the... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00098/20940/18558.pdf |
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| Bourjea, Jerome; Mortimer, Jeanne A.; Garnier, Julie; Okemwa, Gladys; Godley, Brendan J.; Hughes, George; Dalleau, Mayeul; Jean, Claire; Ciccione, Stephane; Muths, Delphine. |
| To refine our understanding of the spatial structure of the green turtle (Chelonia mydas) populations in the South West Indian Ocean (SWIO), we analysed patterns of mitochondrial DNA (396 base pairs control region fragment) variation among 171 samples collected at five distinct locations (Kenya, Northern Mozambique, and three locations in the Republic of Seychelles: the Granitic, Amirantes, and Farquhar groups) and compared them to genetic data (n = 288), previously collected from 10 southern locations in the SWIO. We also analysed post-nesting satellite tracks (n = 4) from green turtles nesting in the Amirantes group. Pairwise comparisons of haplotype frequencies showed significant genetic differentiation amongst rookeries and suggest that the SWIO hosts... |
| Tipo: Text |
Palavras-chave: Indian Ocean; MtDNA; Satellite tracking; Phylogeography; Management unit; Chelonia mydas. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00266/37732/36062.pdf |
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| Lauret-stepler, Marie; Bourjea, Jerome; Roos, David; Pelletier, Dominique; Ryan, P.g.; Ciccione, Stephane; Grizel, Henri. |
| 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... |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00018/12917/9874.pdf |
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| Narazaki, Tomoko; Nakamura, Itsumi; Aoki,, Kagari; Iwata, Takashi; Shiomi, Kozue; Luschi, Paolo; Suganuma, Hiroyuki; Meyer, Carl G.; Matsumoto, Rui; Bost, Charles A.; Handrich, Yves; Amano, Masao; Okamoto, Ryosuke; Mori, Kyoichi; Ciccione, Stephane; Bourjea, Jerome; Sato, Katsufumi. |
| Advances in biologging technology have enabled 3D dead-reckoning reconstruction of marine animal movements at spatiotemporal scales of meters and seconds. Examining high-resolution 3D movements of sharks (Galeocerdo cuvier, N = 4; Rhincodon typus, N = 1), sea turtles (Chelonia mydas, N = 3), penguins (Aptenodytes patagonicus, N = 6), and marine mammals (Arctocephalus gazella, N = 4; Ziphius cavirostris, N = 1), we report the discovery of circling events where animals consecutively circled more than twice at relatively constant angular speeds. Similar circling behaviors were observed across a wide variety of marine megafauna, suggesting these behaviors might serve several similar purposes across taxa including foraging, social interactions, and navigation. |
| Tipo: Text |
Palavras-chave: Ecology; Biological Sciences; Zoology; Animals; Ethology. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00685/79664/82429.pdf |
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| Benhamou, Simon; Sudre, Joël; Bourjea, Jerome; Ciccione, Stephane; De Santis, Angelo; Luschi, Paolo. |
| Background: Laboratory and field experiments have provided evidence that sea turtles use geomagnetic cues to navigate in the open sea. For instance, green turtles (Chelonia mydas) displaced 100 km away from their nesting site were impaired in returning home when carrying a strong magnet glued on the head. However, the actual role of geomagnetic cues remains unclear, since magnetically treated green turtles can perform large scale (.2000 km) post-nesting migrations no differently from controls. Methodology/Principal Findings: In the present homing experiment, 24 green turtles were displaced 200 km away from their nesting site on an oceanic island, and tracked, for the first time in this type of experiment, with Global Positioning System (GPS), which is able... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00048/15958/13390.pdf |
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| Dalleau, Mayeul; Benhamou, Simon; Sudre, Joel; Ciccione, Stephane; Bourjea, Jerome. |
| While our understanding of the early oceanic developmental stage of sea turtles has improved markedly over recent decades, the spatial context for this life history stage remains unknown for Indian Ocean loggerhead turtle populations. To address this gap in our knowledge, 18 juvenile loggerheads were satellite tracked from Reunion Island (21.2A degrees S, 55.3A degrees E) between 2007 and 2011. Nine turtles swam north toward Oman (20.5A degrees N, 58.8A degrees E), where one of the world's largest rookeries of loggerheads is located. Three individuals traveled south toward South Africa and Madagascar, countries that also host loggerhead nesting grounds. Fourteen of the transmitters relayed diving profiles. A dichotomy between diurnal and nocturnal diving... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00210/32173/32178.pdf |
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| Jean, Claire; Ciccione, Stephane; Ballorain, Katia; Georges, Jean-yves; Bourjea, Jerome. |
| Reunion Island in the south-west Indian Ocean once had significant nesting populations of marine turtles but they declined rapidly after human colonization. In 1996, after regular sightings of turtles offshore, an aerial survey programme was initiated to monitor the occurrence of marine turtles and their distribution along the west coast of the island Between 1998 and 2008, along a 30-km coastline transect between Saint Leu and Saint Paul, a total of 1,845 marine turtle sightings were recorded during 146 flights with an ultralight aircraft The mean number of turtle sightings per survey increased significantly between 1998 and 2008, and a variety of sizes were recorded throughout the year Marine turtles were found over coral reef zones and on the outer reef... |
| Tipo: Text |
Palavras-chave: Abundance; Aerial survey; Conservation; Indian Ocean; Marine turtles; Reunion Island. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00005/11588/9280.pdf |
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| Registros recuperados: 18 | |
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