73 research outputs found
Regional Management Units for Marine Turtles: A Novel Framework for Prioritizing Conservation and Research across Multiple Scales
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
Avis de l'Ifremer pour la création d'une zone de cantonnement au large de Brescou, commune d'Agde
Minute Report of the 1st workshop on joint analysis of sea turtle mitigation effectiveness. Honolulu, USA, 16â19 February 2016
The Areas Beyond National Jurisdiction (ABNJ, or Common Oceans) Tuna Project is a Global Environment Facility (GEF)-funded, FAO-implemented programme of work designed to encourage and reinforce sustainable tuna fisheries. One of the three main components of the project focuses on mitigating bycatch and ameliorating adverse impacts on biodiversity. Taking its cue from a work plan developed by the Joint t-RFMO Technical Working Group- Bycatch, the ABNJ Tuna Project aims to progress prioritized research on sea turtle bycatch mitigation through encouraging data sharing and collaborative analysis (Joint Tuna RFMOs 2011). Funding has been allocated to WCPFC and The Pacific Community (SPC) under the ABNJ work programme to support two sets of workshops on bycatch mitigation issues facing t-RFMOs. The first workshops (this one and another to be held in late 2016) are designed to focus on assessing the effects of mitigation on interaction and at-vessel mortality rates of sea turtles in pelagic longline fisheries
Analysis of the genetic structure and life history of albacore tuna in terms of diversity, abundance and migratory range at the spatial and time scales: Project GERMON (GEnetic stRucture and Migration Of albacore tuNa)
Tunas are important commercial species that represent a share of about 8 percent of total fish exports. In 2010, the total catch of tuna in three oceans was about 6.6 million tons, 4.3 million tons for the most marketed species, a level roughly stable since 2002 (FAO 2012).
Among these tuna species, there are in descending order of capture: skipjack tuna (Katsuwonus pelamis), yellowfin tuna (Thunnus albacares), bigeye tuna (Thunnus obesus), albacore tuna (Thunnus alalunga) and bluefin tuna (Thunnus thynnus).
Overall, the biology of albacore stock in the Indian Ocean is not well known and there is relatively little new recent information on albacore stocks. Albacore life history characteristics, including a relatively late maturity, long life and sexual dimorphism, make the species vulnerable to over exploitation. This species is a highly migratory species. It is found around the world in warm, temperate waters and can migrate thousands of kilometers each year across an entire ocean, but the relations between albacore populations across the oceans are uncertain. This species has been studied mainly in the Atlantic and the North Pacific, and very little is known about this species in the southern regions and tropics. In the Pacific and Atlantic oceans there is a clear separation of southern and northern stocks associated with the oceanic gyres that are typical of these areas. In the Indian Ocean, it is thought that there is only one southern stock, distributed from 5°N to 45°S, because there is no northern gyre and low caught in northern regions. This hypothesis needs to be investigated and more particularly the link that does exist between Indian Ocean and south Atlantic. In South African waters, huge numbers of juveniles are observed and the source is still unknown. Determinate this source is of primary concern for Regional Fishery Management Organization which amounts to the question of the relationship between these two oceans (Figure 1)
Glorieuses 2008. Mission Tortue du 4 au 7 mai 2008. Rapport de mission scientifique dans les Eparses
Les objectifs de cette mission Ă©taient les suivants :
Composante 1 : Etude des Processus de navigation des tortues vertes dans le sud ouest de l'OcĂ©an Indien. Sur la base de 12 tortues dĂ©placĂ©es Ă 100 milles de leur plage de ponte, en direction de l'ouest, afin de disposer d'un point de lĂącher Ă©loignĂ© des principales Ăźles de la rĂ©gion (Comores, Mayotte, Madagascar, Seychelles), les processus de navigation et dâorientation en fonction du champs magnĂ©tique terrestre et des courants seront Ă©tudiĂ©es grĂące Ă des balises Argos.
Composante 2 : Importance des Ăźles du Sud Ouest de lâocĂ©an Indien en tant quâhabitat de dĂ©veloppement pour les tortues marines. Dans la continuitĂ© des missions rĂ©alisĂ©es ces 3 derniĂšres annĂ©es dans les Ăźles Eparses, une campagne de marquage / relecture sera rĂ©alisĂ©e dans le lagon de Glorieuses afin dâĂ©tudier les taux de rĂ©sidence et dâaccroissement des immatures de tortue verte et imbriquĂ©e.
Composante 3 : Etude de la connectivitĂ© des aires marines protĂ©gĂ©es du sud ouest de lâocĂ©an Indien. Afin dâoptimiser la mission, des campagnes dâĂ©chantillonnage seront menĂ©es sur 3 espĂšces de poisson corallien (E. Merra, L. kasmira et M. Berndti) selon lâarrĂȘtĂ© TAAF n°2008-29 du 18 avril 200
Rapports sur la mise en Ćuvre des dĂ©rogations aux plans de gestion gangui et senne de plage
Review and Cartography of scientific literature on Thunnus alalunga
Albacore tuna (Thunnus alalunga) is an economically valuable species worldwide. However information on this species is sparse in some scientific fields according to oceans. This disparity has been revealed from bibliometric analysis. Here, we presented the clustering map and the classification of scientific fields by ocean
Differentiation of albacore stock: review by oceanic regions
Because one of the most common problems in fisheries is the definition of management units, we propose in this paper a bibliometric review focusing on the differentiation of Albacore populations, Thunnus alalunga, among and within oceanic regions (Atlantic, Pacific and Indian Oceans, and Mediterranean Sea). This paper is the first step of a current work on a global review of Albacore tuna using an international aquatic database (ASFA). For the present purpose, 367 publications, mainly composed of articles (64%), but also conference papers, proceedings and reports (24%), and books (12%), were analyzed. We will see that the concept of the stock and its delimitation is controversial because of the divergence of results. Such a conclusion makes us believe in the urgent need of further studies targeting this currently overexploited species in most regions of the world, in order to improve management units currently used by regional organizations for fishery management.Parce que lâun des problĂšmes les plus rĂ©currents en halieutique est la dĂ©finition mĂȘme des unitĂ©s de gestion, nous proposons dans ce papier un aperçu bibliographique traitant de la diffĂ©rentiation des populations de thon germon, Thunnus alalunga, au sein et entre les rĂ©gions ocĂ©aniques (lâocĂ©an Atlantique, Pacifique et Indien, et la mer MĂ©diterranĂ©e). Ce papier est la premiĂšre Ă©tape dâune revue en cours de rĂ©daction sur le thon germon dans laquelle nous avons utilisĂ© une base de donnĂ©es internationale aquatique (ASFA). Un total de 367 publications ont Ă©tĂ© traitĂ© comprenant principalement des articles scientifiques (64%), puis des confĂ©rences et rapports (24%), et des ouvrages (12%). Nous verrons que la notion de stock pour cette espĂšce et leur dĂ©limitation sont ambigĂŒes du fait des rĂ©sultats divergents des Ă©tudes et de leur nature. Le principal constat est le besoin immĂ©diat de travaux supplĂ©mentaires sur cette espĂšce considĂ©rĂ©e surexploitĂ©e dans la plupart des rĂ©gions du monde et qui permettrait dâamĂ©liorer les limites des unitĂ©s de stock actuellement utilisĂ©es par les organisations rĂ©gionales des pĂȘches.Dado que uno de los problemas mĂĄs comunes en las pesquerĂas es la definiciĂłn de unidades de ordenaciĂłn en este documento se propone una revisiĂłn bibliomĂ©trica centrada en la diferenciaciĂłn de las poblaciones de atĂșn blanco (Thunnus alalunga) entre y dentro de las regiones oceĂĄnicas (ocĂ©anos AtlĂĄntico. PacĂfico e Ăndico y mar MediterrĂĄneo).).Este documento es el primer paso de una revisiĂłn global del atĂșn blanco realizada mediante el uso de la base de datos acuĂĄtica internacional (ASFA). En el documento se analizaron 367 publicaciones, sobre todo compuestas de artĂculos cientĂficos (64%), pero tambiĂ©n incluĂa la revisiĂłn de documentos, actas e informes de conferencias (24%) y libros (12%). Se puede observar que debido a las divergencias en los resultados, el concepto de stock y su delimitaciĂłn sigue siendo un tema controvertido. Dichas conclusiones nos llevan a creer en la urgente necesidad de realizar estudios adicionales centrados en esta especie actualmente sobreexplotada en la mayorĂa de las regiones del mundo, con el fin de mejorar las unidades de ordenaciĂłn utilizadas actualmente por las organizaciones regionales para fines de ordenaciĂłn de pesquerĂas
EXPEDITION EUROPA 2011. Rapport de Mission Europa, 16 Novembre â 2 dĂ©cembre 2011 - IFREMER/ KELONIA / CNRS
Cette mission scientifique sâest dĂ©roulĂ©e dans le cadre du projet DYMITILE II (Dynamique Migratoire des Tortues marines nidifiant dans les Iles françaises de lâocĂ©an Indien) en vue de la rĂ©daction des recommandations scientifiques pour la mise en place dâun plan national dâaction pour la conservation de ces espĂšces dans les territoires français de lâocĂ©an Indien. Cette mission avait 3 objectifs principaux :
- contribuer Ă la meilleure comprĂ©hension des voies migratoires des tortues vertes femelles en migration post reproductive dans les principaux sites de ponte du sud-ouest de lâocĂ©an Indien. Compte tenu du succĂšs des prĂ©cĂ©dents dĂ©ploiements de balises, nous avons dĂ©cidĂ© de focaliser la mission sur les tortues dans la mangrove.
- Contribuer à mieux comprendre le comportement des immatures de tortues vertes et imbriquées sur leur habitat de développement via 2 approches : (i) par marquage/relecture et (ii) déploiement de balises Argos-GPS.
- Valoriser les rĂ©sultats acquis sur place par la production dâun film de 26 mn
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