Éditeur(s) : Cambridge Univ Press
Résumé : This paper offers a theoritical and empirical model of ecosystem-based fishery management. A multi-species and multi-fleet integrating Lotka-Volterra trophic dynamics as well as production and profit assessments is developed and applied to the coastal fishery of French Guiana. This small-scale fishery constitutes a challenging example with high fish biodiversity, several non-selective fleets and a potentially increasing local food demand due to demographic growth. The dynamic model is calibrated with 13 species and four fleets using monthly catch and effort data from 2006 to 2009. Several contrasted fishing scenarios including status quo, total closure, economic and viable strategies are then simulated. They are compared from the viewpoints of both biodiversity preservation and socioeconomic performance, assuming fixed landing prices and fixed costs. We show that fishing outputs, including food supply and fleet profitability, can be sustained on average but a loss of species cannot be avoided.
Environment And Development Economics (1355-770X) (Cambridge Univ Press), 2013-06 , Vol. 18 , P. 245-269

Droits : Cambridge University Press 2013
http://archimer.ifremer.fr/doc/00124/23483/21311.pdf
http://archimer.ifremer.fr/doc/00124/23483/21375.pdf
DOI:10.1017/S1355770X13000065
http://archimer.ifremer.fr/doc/00124/23483/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : The paper focuses on investigation of the importance of nature and development of tourism in protected areas. Therefore, in this context a new challenge is emerging: the need to conserve and protect bio and geo diversity, as well as the economic valorisation of these areas based mainly on tourism and leisure. At EU level, Natura 2000 protected areas have developed, implemented and cultivated the need to practice sport and recreational activities in these areas both for spending leisure time and also as stress antidote. The recreational and sporting practices that can be undertaken within the ecological network Natura 2000 sites adapted to the specificity of each protected area, in close connection with the environmental conditions. For the preservation of the natural environment should develop and maintain a close collaboration with tourism and sports associations that organize such activities in those areas.
La réflexion est centrée sur l’importance de la nature et des enjeux du développement de tourisme dans les aires protégées. Un nouveau défi émerge dans le contexte actuel où il s'agit de concilier le besoin de conserver et de protéger la géodiversité et la biodiversité avec la valorisation économique de ces espaces naturels investis par les pratiques touristiques et récréatives. Au niveau de l'Union européenne, les espaces protégés Natura 2000 ont mis en œuvre des programmes permettant de répondre à l’accueil des activités sportives et de loisirs dans ces zones, tant pour passer du temps libre que comme antidote au stress. Ces pratiques entreprises dans le réseau écologique Natura 2000 sites sont adaptés à la spécificité de chaque secteur protégé, en relation avec les conditions environnementales. Pour favoriser la conservation du cadre naturel, il est important de maintenir une étroite collaboration avec les associations touristiques et sportives qui organisent des activités dans ces zones.
Bihor
Roumanie

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.11262
http://journals.openedition.org/etudescaribeennes/11262

Éditeur(s) : HAL CCSD
Résumé : Differentiation of the lithospheric mantle occurred principally through partial melting and extraction of melts. Harzburgites are generally considered as melting residues whereas lherzolites are regarded as pristine mantle weakly affected by melting. However, some orogenic peridotites show evidence of igneous refertilization. In this context, this work re-investigates the nature of the Lherz lherzolites (Pyrenees), type-locality of lherzolites, described as a piece of preserved fertile mantle. Structural and geochemical data show that these lherzolites are not pristine but formed through a refertilization reaction between MORB-like melts and refractory lithosphere. Moreover, the Lherz peridotites were partly used to infer the composition of the primitive upper mantle and these results may have important implications for the nature of the late veneer. Additionally, crystal-preferred orientations of minerals (CPO) highlight a strong feedback between melt percolation and finite strain in the percolated rocks. CPO variations are ruled by a subtle balance between instantaneous melt fraction and local strain rate. This work also investigated the effect of melt percolation on Hf, Nd and Sr isotopes. Isotope systematics in Lherz shows that strong isotopic decoupling may arise in a percolation front. The modelling suggests that decoupled isotopic signatures are generated during porous flow and governed by the melt/matrix elements concentrations, chemical diffusivities or efficiency of isotopic homogenization. Melt-rock interactions can generate “intraplate-like” isotopic signatures. This suggests that a part of isotopic signatures of mantle-related rocks could be generated by diffusional processes associated with melt transport.
La différenciation du manteau lithosphérique s'est principalement effectuée par fusion partielle et extraction de magmas. Les harzburgites sont généralement considérées comme des résidus de fusion tandis que les lherzolites représentent un manteau originel peu affecté par la fusion. Cependant, certaines péridotites orogéniques montrent des évidences de refertilisation magmatique. Dans ce contexte, ce travail remet en cause la nature primitive des lherzolites de Lherz (Pyrénées), lithotype de la lherzolite. Les données structurales et géochimiques montrent que ces lherzolites ne représentent pas du manteau préservé mais qu'elles se sont formées par une réaction de refertilisation entre un liquide de type MORB et une lithosphère réfractaire. De plus, les orientations préférentielles de réseau (OPR) des minéraux montrent une forte interdépendance entre la percolation magmatique et la déformation finie observée dans les roches percolées. Les variations d'OPR semblent contrôlées par un équilibre subtil entre fraction de liquide instantanée et taux de déformation local. Ce travail a également abordé les effets de la percolation magmatique sur la variabilité isotopique des roches mantelliques. Les résultats montrent qu'un fort découplage isotopique peut s'observer dans un front de percolation. Les modèles suggèrent que le découplage des signatures isotopiques se produit pendant la percolation, gouverné par le rapport des concentrations en éléments (magma/matrice), la diffusivité et le processus d'homogénéisation isotopique. Les réactions magma/roche peuvent générer des signatures isotopiques de type intraplaque. Ceci suggère qu'une part des signatures isotopiques des roches ou laves dérivées du manteau pourrait être produite par des processus diffusionnels associés à du transport de magma.
https://tel.archives-ouvertes.fr/tel-00431325

tel-00431325
https://tel.archives-ouvertes.fr/tel-00431325
https://tel.archives-ouvertes.fr/tel-00431325/document
https://tel.archives-ouvertes.fr/tel-00431325/file/theseleroux08.pdf

Éditeur(s) : University of Tasmania, Université de Bretagne Occidentale
Résumé : Empirical evidence and the theoretical literature both point to stock sustainability and the protection of marine biodiversity as important fisheries management issues. Decision-support tools are increasingly required to operationalize the ecosystem-based approach to fisheries management. These tools need to integrate (i) ecological and socio-economic drivers of changes in fisheries and ecosystems; (ii) complex dynamics; (iii) deal with various sources of uncertainty; and (iv) incorporate multiple, rather than single objectives. The stochastic co-viability approach addresses the trade-offs associated with balancing ecological, economic and social objectives throughout time, and takes into account the complexity and uncertainty of the dynamic interactions which characterize exploited ecosystems and biodiversity. This thesis proposes an application of this co-viability approach to the sustainable management of mixed fisheries, using two contrasting case studies: the French Bay of Biscay (BoB) demersal mixed fishery and the Australian Northern Prawn Fishery (NPF). Both fisheries entail direct and indirect impacts on mixed species communities while also generating large economic returns. Their sustainability is therefore a major societal concern. A dynamic bio-economic modelling approach is used to capture the key biological and economic processes governing these fisheries, combining age- (BoB) or size- (NPF) structured models of multiple species with recruitment uncertainty, and multiple fleets (BoB) or fishing strategies (NPF). Economic uncertainties relating to input and output prices are also considered. The bioeconomic models are used to investigate how the fisheries can operate within a set of constraints relating to the preservation of Spawning Stock Biomasses (BoB) or Spawning Stock Size Indices (NPF) of a set of key target species, maintenance of the economic profitability of various fleets (BoB) or the fishery as a whole (NPF), and limitation of fishing impacts on the broader biodiversity (NPF), under a range of alternative scenarios and management strategies. Results suggest that under a status quo strategy both fisheries can be considered as biologically sustainable, while socio-economically (and ecologically in the NPF case) at risk. Despite very different management contexts and objectives, viable management strategies suggest a reduction in the number of vessels in both cases. The BoB simulations allow comparison of the trade-offs associated with different allocations of this decrease across fleets. Notably, co-viability management strategies entail a more equitable allocation of effort reductions compared to strategies aiming at maximizing economic yield. In the NPF, species catch diversification strategies are shown to perform well in controlling the levels of economic risk, by contrast with more specialized fishing strategies. Furthermore analyses emphasize the importance to the fishing industry of balancing global economic performance with inter-annual economic variability. Promising future developments based on this research involve the incorporation of a broader set of objectives including social dimensions, as well as the integration of ecological interactions, to better address the needs of ecosystem-based approaches to the sustainable harvesting of marine biodiversity.
L’objectif général de la thèse est de modéliser les principaux processus biologiques et économiques régissant des pêcheries multi-espèces et multi-flottilles afin de proposer des stratégies viables pour la gestion durable de ces pêcheries mixtes, dans un contexte stochastique et multiobjectif. Plus spécifiquement, cette thèse utilise des analyses de co-viabilité stochastique pour étudier les arbitrages entre des objectifs contradictoires de gestion (conservation, et viabilité économique et sociale) des pêcheries mixtes. Deux pêcheries mixtes sont analysées dans cette thèse: la pêcherie française mixte démersale du golfe de Gascogne et la pêcherie crevettière australienne du Nord (NPF). Ces deux pêcheries sont multi-espèces, et utilisent des stratégies multiples de pêche, induisant des impacts directs et indirects sur les écosystèmes. Cette thèse propose une application de la co-viabilité stochastique à ces deux cas, en prenant en compte leur histoire, leur contexte socio-politique et les différences dans les stratégies et objectifs de gestion. Les résultats suggèrent que le status quo peut être considéré comme une stratégie biologiquement durable mais socio économiquement à risque dans les deux pêcheries (ainsi qu’à risque écologique dans le cas de la pêcherie australienne). Les simulations réalisées pour le golfe de Gascogne permettent de comparer les arbitrages associés à différentes réductions de capacités par flottille et de montrer qu’il existe des solutions de gestion permettant la co-viabilité du système (viabilité biologique des différentes espèces considérées et viabilité socio-économique des flottilles) contrairement à des stratégies de gestion mono-spécifiques ou basées sur la maximisation de la rente. Dans la pêcherie crevettière australienne, l’analyse montre que les stratégies de diversification permettent de limiter le risque économique contrairement aux stratégies plus spécialisées.

Droits : UBO, Univ. Tasmania
http://archimer.ifremer.fr/doc/00206/31731/30134.pdf
http://archimer.ifremer.fr/doc/00206/31731/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Ce numéro de la Revue Études Caribéennes s’intéresse aux liens qui unissent et opposent l’activité touristique et les ressources naturelles, particulièrement dans les pays du Sud. Dans un contexte de médiatisation accrue des enjeux liés à la biodiversité et aux menaces qui pèsent sur elle, le tourisme – et particulièrement l’écotourisme – est souvent présenté comme un moyen de concilier la conservation et le développement. Les autorités locales, malgré l’existence d’un cadre réglementaire propre à l’environnement, ne disposent souvent pas de moyens suffisants (humains, matériels et financiers) pour gérer la croissance de la fréquentation des aires protégées et ses effets potentiels sur l’environnement naturel et humain. En réponse à cette problématique, les institutions financières internationales et les organismes associés proposent aux pays du Sud de trouver un équilibre entre une fréquentation de masse et une fréquentation de bas volume afin de développer « un tourisme de haute qualité ». Même si cela était possible, quels critères peuvent être utilisés pour « cesser » le développement d’un pôle ou d’une région touristique ? L’évolution géographique « naturelle » du tourisme – c’est-à-dire essentiellement basée sur la mise en tourisme de la nature et sur l’accessibilité de ces ressources – pose déjà des problèmes politiques et économiques importants. Les gouvernements (central, régional ou local) sont difficilement en mesure de réaliser un arbitrage de long terme dans ce contexte qui permettrait l’adéquation entre le développement touristique et la préservation des espaces naturels. La relation entre le tourisme et les ressources naturelles s’articule souvent autour de deux objectifs spécifiques, soient : développer un produit à moindre impact, mais aux dépenses élevées et viser un volume de visiteurs qui contribue aux profits économiques, mais qui amène le moins de dégradation écologique/sociale possible. Cette position résume à elle seule à la fois la complexité et les multiples paradoxes dans lesquels s’insère la mise en tourisme de la nature. Les dynamiques sociales et l’extension de l’appropriation privative des espaces naturels et agricoles posent la problématique des modes de gestion des ressources communes et de leur pérennité, particulièrement dans les pays du Sud. Dans ce contexte, les objectifs, les ressources et les stratégies des principaux acteurs concernés sont difficilement conciliables et le système de relation qu’il induit n’est pas nécessairement en phase avec les finalités poursuivies. This edition of Revue Etudes Caribéennes focuses on the links that unite and oppose tourism and natural resources, specifically in southern countries. In a context of increased media coverage of issues related to biodiversity (including threats to it), tourism – particularly ecotourism – is often presented as a mean to reconcile conservation and development. Local authorities, despite the existence of a specific environmental regulatory framework, often have insufficient resources (human, material, financial) to manage the increase of visits to protected areas, and the potential impact of these visits on natural and human environments. In response to this problem, international financial institutions and associated organizations offer to try to find a balance between mass attendance and low volume attendance in order to develop "high quality tourism" in southern countries. Even if this were possible, what criteria can be used to "stop" the development of a tourist site or region for environmental reasons? The “natural” geographic evolution of tourism – in other words, essentially based on the development of nature tourism and accessibility of these resources – already causes huge political and economic problems. Governments (central, regional or local) are hardly able to arbitrate over the long term in a context that would allow finding a balance between tourism development and preservation of natural areas. The relationship between tourism and natural resources often revolves around two specific objectives: to develop a product with less impact, but at high cost and a target volume of visitors that contributes to economic profits, but that causes the least ecological / social degradation possible. This position epitomizes both the complexity and the many paradoxes of nature tourism development. Social interactions and the expansion of private appropriation of natural and agricultural areas highlight the challenges of managing common resources and their sustainability, especially in the southern countries. In this context, development objectives, natural resources and the strategies of key stakeholders are difficult to reconcile, and the relationship between leading actors do not always correspond with these objectives. Esta edición de “Revue Études Caribéennes” se interesa a los lazos que unen y separan la actividad turística y los recursos naturales, particularmente en los países del sur. En un contexto de mediatización en alza sobre los objetivos ligados a la biodiversidad y a las amenazas que pesan sobre ella, el turismo – y particularmente el ecoturismo – está a menudo presentado como un medio de conciliar la conservación y el desarrollo. Las autoridades locales, pese a la existencia de un cuadro propio de reglamentación al medio ambiente, no disponen habitualmente de suficientes medios (humanos, materiales y financieros) para controlar el aumento de visitas en las áreas protegidas y sus efectos potenciales sobre el ambiente natural y humano. En respuesta a esta problemática, las instituciones financieras internacionales y los organismos asociados proponen a los países del sur encontrar un equilibrio entre la frecuentación de masas y una frecuentación de bajo volumen con el objetivo de desarrollar “un turismo de alta calidad”. Incluso si fuese posible, ¿qué criterios podrían ser utilizados para “cesar” el desarrollo de un centro o una región turística? La evolución geográfica “natural” del turismo – esencialmente basada en el desarrollo del turismo de la naturaleza y el acceso de sus recursos – crean problemas políticos y económicos enormes. Los gobiernos (central, regional o local) tienen dificultades para realizar un arbitraje a largo plazo en este contexto que permitiría la adecuación entre el desarrollo turístico y la preservación de los espacios naturales. La relación entre el turismo y los recursos naturales se articula a menudo alrededor de dos objetivos específicos, sean: desarrollar un producto con mínimo impacto, pero con gastos elevados y aspirar a un volumen de visitantes que contribuya a las ganancias económicas, pero que traiga la menor degradación ecológica/social posible. Esta posición resume la complejidad y las múltiples paradojas en las cuales se encaja la puesta del turismo en la naturaleza. Las dinámicas sociales y la extensión de la apropiación privativa de los espacios naturales y agrícolas plantean una problemática en los modos de gestión de los recursos comunes y de su perennidad, particularmente en los países del sur. En este contexto, los objetivos, los recursos y las estrategias de los principales actores concernidos son difícilmente conciliables y el sistema de relación que induce no es necesariamente en la misma fase con los objetivos perseguidos.

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.7884
http://journals.openedition.org/etudescaribeennes/7884

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
The Iberian Massif is the best exposed segment of the European Variscan Belt. It includes relatively well preserved terranes that were accreted by transpression along time and resulted in a number of geotectonic units that formed part of the Late Paleozoic assembly of the Pangaea Supercontinent. In SW Iberia, these units are the Central Iberian Zone (CIZ), Ossa Morena Zone (OMZ), and the South Portuguese Zone (SPZ). A 210 km long NE-SW magnetotelluric profile was carried out through the CIZ, from the OMZ-CIZ boundary toward the north, reaching the Tagus (Cenozoic) basin. Data dimensionality analysis resulted in a suitable 2-D electrical resistivity structure, allowing a 2-D inversion of the data set. Complementary available geophysical data (deep seismic, gravity and aeromagnetic) and a comparison with a detailed geological cross section led us to constrain the interpretation of the 2-D electrical resistivity structure of the CIZ crust. The results show, for the upper crust, the existence of diverse conductive/resistive bodies that correlate well with known geological features (sedimentary basins, faults, granitic plutons, mineralized systems). A mild but steady conductive band is located along the middle and lower crust that is interpreted as a mafic granulite basement. The upper section of this band connects with several elongated shallow conductors, providing further evidence for the existence, in the Central Iberian Zone, of a complex decollement system where the major faults are rooted. Such a crustal architecture is viewed as the northward continuation of the Variscan large-scale structures previously recognized in the southern sectors (OMZ and SPZ).
ISSN: 0148-0227

hal-00671036
https://hal.archives-ouvertes.fr/hal-00671036
DOI : 10.1029/2010JB007538

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 Elsevier Masson
Résumé : International audience
Late Jurassic coral reefs are present in the Western High Atlas of Morocco along the eastern paleomargin of the young Atlantic Ocean. The Izwarn section shows two reef units made of scleractinian corals and microbialites, included in a progradational shallowing-upward succession. Changes in reefal composition and structure observed in a ca. 50 cm-thick interval at the base of the reef unit 1 are interpreted to represent the first well-documented ecological succession in Late Jurassic reefs. Bioclastic deposits, sparse and poorly diversified corals (five genera) preserved in life position, and finally a more diversified coral assemblage (11 genera) building a reef framework with stromatolitic crusts reflect pioneer, colonization and diversification stages, respectively. A specific depth window, where light was reduced but sufficient for a catch-up growth mode and below the erosive action of waves, probably at the lower slope of a fore-reef area, has made possible the development and the record of this ecological succession. With a more diversified coral assemblage (16 genera), the reef unit 2 reflects shallower and well-agitated waters of a fore-reef area. Overlaying this second reef unit, the upper part of the section reveals back-reef deposits made of reworked reef elements, whereas a putative reef crest area is not recorded.
ISSN: 0016-6995

hal-00795549
https://hal.archives-ouvertes.fr/hal-00795549
DOI : 10.1016/j.geobios.2012.05.002

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The In Ouzzal terrane in western Hoggar (Southern Algeria) preserves evidence of ultrahigh temperature (UHT) crustal metamorphism. It consists in Archean crustal units, composed of orthogneissic domes and greenstone belts, strongly remobilized during the Paleoproterozoic orogeny which was recognized as an UHT event (peak T > 1000 °C and P ≈ 9–12 kbar). This metamorphism was essentially defined locally in Al-Mg granulites, Al-Fe granulites and quartzites outcropping in the Northern part of the In Ouzzal terrane (IOT).In order to test and verify the regional spread of the UHT metamorphism in this terrane, ternary feldspar thermometry on varied rock types (Metanorite, Granulite Al-Mg and Orthogneiss) and samples that crop out in different zones of the In Ouzzal terrane. These rocks contain either perthitic, antiperthitic or mesoperthitic parageneses. Ternary feldspars used in this study have clearly a metamorphic origin.The obtained results combined with previous works show that this UHT metamorphism (>900 °C) affected the whole In Ouzzal crustal block. This is of major importance as for future discussion on the geodynamic context responsible for this regional UHT metamorphism.
ISSN: 0899-5362

hal-01526950
https://hal.archives-ouvertes.fr/hal-01526950
DOI : 10.1016/j.jafrearsci.2016.08.005

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
In the Tahalgha district (southwestern Hoggar, Algeria), the Cenozoic volcanism has sampled subcontinental mantle beneath two crustal terranes that collided during the Pan-African orogeny: the “Polycyclic Central Hoggar” to the east and the “Western Hoggar” to the west. Two major lithospheric shear zones separate these terranes: the “4°35” and the “4°50” faults. Mantle xenoliths were collected between the two faults and across the 4°35 fault. In addition to a range in equilibrium temperatures and chemical compositions reported elsewhere, the samples show variations in their microstructures and crystallographic preferred orientations. Equilibrium temperatures and geochemical characteristics allow dividing them into low — (LT; 700–900 °C), intermediate — (IT; 900–1000 °C), and high-temperature (HT; 1000–1100 °C) xenoliths. The LT and IT peridotites occur on both sides of the 4°35 fault; they are usually coarse-grained. HT xenoliths are present only east of the 4°35 fault, in the narrow domain stuck between the two faults; they are fine-grained and extensively affected by annealing and melt–rock reactions. Microstructures and crystallographic textures indicate that deformation in the LT- and IT-xenoliths occurred through dislocation creep under relatively high-temperature, low-pressure conditions, followed by post-kinematic cooling. The fine-grained HT-xenoliths were deformed under relatively high-stress conditions before being annealed.Combining microstructural and CPO data with petrological and geochemical informations suggests that: (1) the LT xenoliths are remnants of the Neoproterozoic lithospheric mantle that preserved microstructural and chemical characteristics inherited from the Pan-African orogeny, and (2) the HT xenoliths record localized Cenozoic deformation associated with melt channeling through feed-back processes that culminated in the formation of high-permeability porous-flow conduits. Limited grain-growth in HT xenoliths suggests that advective heating of melt conduits was transient and rapidly followed by thermal relaxation due to conductive heat loss into wall-rock peridotites represented by the IT xenoliths, then by exhumation due to volcanic activity.
ISSN: 0040-1951

hal-01171761
https://hal.archives-ouvertes.fr/hal-01171761
DOI : 10.1016/j.tecto.2014.11.012

Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé : International audience
New petrographic and microstructural observations, mineral equilibria modelling and U/Pb (monazite) geochronological studies were carried out to investigate the relationships between deformation and metamorphism across the Rehamna massif (Moroccan Variscan belt). In this area, typical Barrovian (muscovite to staurolite) zones developed in Cambrian to Carboniferous metasedimentary rocks that are distributed around a dome-like structure. First assemblages are characterized by the presence of locally preserved andalusite, followed by prograde evolution culminating at 6 kbar and 620 °C in the structurally deepest staurolite zone rocks. This Barrovian sequence was subsequently uplifted to supracrustal levels, heterogeneously reworked at greenschist facies conditions, which was followed locally by static growth of andalusite, indicating heating to 2.5–4 kbar and 530–570 °C. The 206Pb/238U monazite age of 298.3 ± 4.1 Ma is interpreted as minimum age of peak metamorphic conditions, whereas the ages of 275.8 ± 1.7 Ma and 277.0 ± 1.1 Ma date decompression and heating at low pressure, in agreement with previous dating of Permian granitoids intruding the Rehamna massif. The prograde metamorphism occurred during thickening and associated horizontal flow in the deeper crust (S1 horizontal schistosity). The horizontally disposed metamorphic zones were subsequently uplifted by a regional scale antiform during ongoing N–S compression. The re-heating of the massif follows late massive E–W shortening, refolding and retrograde shearing of all previous fabrics coevally with regionally important intrusions of Permian granitoids. We argue that metamorphic evolution of the Rehamna massif occurred several hundred kilometres from the convergent plate boundaries in the interior of continental Gondwanan plate. The tectonometamorphic history of the Rehamna massif is put into Palaeozoic plate tectonic perspective and Late Carboniferous reactivation of (Devonian)–Early Carboniferous basins formed during stretching of the north Gondwana margin and formation of the Palaeotethys Ocean. The inherited heat budget of these magma-rich basins plays a role in the preferential location of this intracontinental orogen. It is shown that rapid transition from lithospheric stretching to compression is characterized by specific HT type of Barrovian metamorphism, which markedly differs from similar Barrovian sequences along Palaeozoic plate boundaries reported from Variscan Europe.
ISSN: 0263-4929

hal-01468009
https://hal.archives-ouvertes.fr/hal-01468009
DOI : 10.1111/jmg.12214

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Cet article vise à mener une analyse juridique du concept de mondialisation. Alors que la mondialisation est souvent décriée comme anti-démocratique, nous démontrerons que d’un point de vue strictement juridique, il apparaît que la réalité est plus nuancée. Nous passerons en revue les critiques de la mondialisation liées à la perte de souveraineté de l’Etat, qui nous paraissent devoir être relativisées à la fois dans son étendue et dans son impact sur la démocratie. Nous montrerons comment le droit international surmonte ces difficultés en permettant un nouvel équilibre entre Etat et individu sur la scène internationale, et comment à un modèle de démocratie traditionnel fondé sur l’Etat est en train de succéder une démocratie fondée sur la société civile transnationale. Enfin, nous évoquerons le rôle essentiel du juge afin de préserver démocratie et état de droit dans l’ordre international, malgré les limites qui lui sont inhérentes.
This article aims to critically analyse the concept of globalization, from a legal standpoint. While globalization is often criticized as anti-democratic, we demonstrate that from a strictly legal point of view, the reality is subtler. We review the criticisms of globalization related to the loss of state sovereignty, which we believe need to be put into perspective in both their extent and their impact on democracy. We show how international law overcomes the new challenges due to globalization by allowing a new balance between the State and the Individual on the international plane. We then show that the classical model of democracy based on the State is being superseded by a democracy based on transnational civil society. Finally, we discuss the essential role of the judge to preserve democracy and rule of law in the international order, despite the limitations inherent to his competences.

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.5876
http://journals.openedition.org/etudescaribeennes/5876

Éditeur(s) : HAL CCSD American Society for Biochemistry and Molecular Biology
Résumé : International audience
Neuroglobins, previously thought to be restricted to vertebrate neurons, were detected in the brain of a photosymbiotic acoel, Symsagittifera roscoffensis, and in neurosensory cells of the jellyfish Clytia hemisphaerica. For the neuroglobin of S. roscoffensis, a member of a lineage that originated either at the base of the bilateria or of the deuterostome clade, we report the ligand binding properties, crystal structure at 2.3 Å, and brain immunocytochemical pattern. We also describe in situ hybridizations of two neuroglobins specifically expressed in differentiating nematocytes (neurosensory cells) and in statocytes (ciliated mechanosensory cells) of C. hemisphaerica, a member of the early branching animal phylum cnidaria. In silico searches using these neuroglobins as queries revealed the presence of previously unidentified neuroglobin-like sequences in most metazoan lineages. Because neural systems are almost ubiquitous in metazoa, the constitutive expression of neuroglobin-like proteins strongly supports the notion of an intimate association of neuroglobins with the evolution of animal neural systems and hints at the preservation of a vitally important function. Neuroglobins were probably recruited in the first protoneurons in early metazoans from globin precursors. Neuroglobins were identified in choanoflagellates, sponges, and placozoans and were conserved during nervous system evolution. Because the origin of neuroglobins predates the other metazoan globins, it is likely that neuroglobin gene duplication followed by co-option and subfunctionalization led to the emergence of globin families in protostomes and deuterostomes (i.e. convergent evolution).
ISSN: 0021-9258

hal-01020584
http://hal.upmc.fr/hal-01020584
http://hal.upmc.fr/hal-01020584/document
http://hal.upmc.fr/hal-01020584/file/Rosko_jbc_revised.pdf
DOI : 10.1074/jbc.M112.407601

Éditeur(s) : Pergamon-elsevier Science Ltd
Résumé : We report rare earth element (REE) and neodymium (Nd) isotope data for the organic fraction of sediments collected from various depositional environments, i.e. rivers (n=25), estuaries (n=18), open-ocean settings (n=15), and cold seeps (n=12). Sedimentary Organic Matter (SOM) was extracted using a mixed hydrogen peroxide/nitric acid solution (20%-H2O2 – 0.02M-HNO3), after removal of carbonate and oxy-hydroxide phases with dilute hydrochloric acid (0.25M-HCl). A series of experimental tests indicate that extraction of sedimentary organic compounds using H202 may be complicated occasionally by partial dissolution of sulphide minerals and residual carbonates. However, this contamination is expected to be minor for REE because measured concentrations in H2O2 leachates are about two-orders of magnitude higher than in the above mentioned phases. The mean REE concentrations determined in the H2O2 leachates for samples from rivers, estuaries, coastal seas and open-ocean settings yield relatively similar levels, with ΣREE = 109 ± 86 ppm (mean ± s; n=58). The organic fractions leached from cold seep sediments display even higher concentration levels (285 ± 150 ppm; mean ± s; n=12). The H2O2 leachates for most sediments exhibit remarkably similar shale-normalized REE patterns, all characterized by a mid-REE enrichment compared to the other REE. This suggests that the distribution of REE in leached sedimentary organic phases is controlled primarily by biogeochemical processes, rather than by the composition of the source from which they derive (e.g. pore, river or sea- water). The Nd isotopic compositions for organic phases leached from river sediments are very similar to those for the corresponding detrital fractions. In contrast, the SOM extracted from marine sediments display εNd values that typically range between the εNd signatures for terrestrial organic matter (inferred from the analysis of the sedimentary detrital fractions) and marine organic matter (inferred from the analysis of local surface seawater). A notable exception is the case of organic matter (OM) fractions leached from cold seep sediment samples, which sometimes exhibit εNd values markedly different from both terrigenous and surface seawater signatures. This suggests that a significant fraction of organic compounds in these sediments may be derived from chemosynthetic processes, recycling pore water REE characterized by a distinct isotopic composition. Overall, our results confirm that organic matter probably plays an important role in the oceanic REE budget, through direct scavenging and remineralization within the water column. Both the high REE abundances and the shape of shale-normalized patterns for leached SOM also suggest that OM degradation in sub-surface marine sediments during early diagenesis could control, to a large extent, the distribution of REE in pore waters. Benthic fluxes of organic-bound REE could hence substantially contribute to the exchange processes between particulates and seawater that take place at ocean margins. Neodymium isotopes could provide useful information for tracing the origin (terrestrial versus marine) and geographical provenance of organic matter, with potential applications in paleoceanography. In particular, future studies should further investigate the potential of Nd isotopes in organic compounds preserved in sedimentary records for reconstructing past variations of surface ocean circulation.
Geochimica Et Cosmochimica Acta (0016-7037) (Pergamon-elsevier Science Ltd), 2014-09 , Vol. 140 , P. 177-198

Droits : 2014 Elsevier Ltd. All rights reserved.
http://archimer.ifremer.fr/doc/00191/30250/28682.pdf
DOI:10.1016/j.gca.2014.05.016
http://archimer.ifremer.fr/doc/00191/30250/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Cet article explore les raisons qui incitent des acteurs sociaux, politiques et économiques à choisir de mettre les ressources naturelles en valeur, par et pour l’écotourisme. Il pose l’hypothèse que l’attractivité de la nature — sur laquelle s’appuie l’écotourisme — n’est pas neutre, c’est-à-dire que les acteurs impliqués dans la sauvegarde de celle-ci le font principalement par intérêt. Par son lien étroit avec la biodiversité, dont les dimensions ne sont pas accessibles à tous, l’écotourisme constitue un vecteur de développement et de consolidation du pouvoir, en particulier celui de « l’éco-pouvoir », c’est-à-dire celui des acteurs qui détiennent les informations sur l’état des ressources naturelles et sur les solutions qui leur sont accessibles.
This article explores the reasons why the social, political and economic stakeholders choose to promote natural resources by means of and for ecotourism. It hypothesizes that the attractiveness of nature-based ecotourism is not revenue neutral - that is, those involved in promoting this approach do so out of self interest. Through its close relationship with biodiversity, the dimensions of which are not appreciated by all, ecotourism is a vehicle for development and consolidation of power, particularly that of "éco-power", that is say those stakeholders who have information on the state of natural resources and the solutions available to them.

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.455
http://journals.openedition.org/etudescaribeennes/455

Éditeur(s) : HAL CCSD
Résumé : The Green and Blue infrastructure (Trame verte et bleue ?TVB) is a new conservation policy tool based on the notions of ecological network and corridor. The TVB's implementation process establishes the connection of multi and nested decisional and action levels and needs permanent adjustment to change that is analyzed as adaptive governance mechanisms. The implementation of an adaptive governance is described as an mean to overpass those failures. The literature on adaptive governance gives learning process a central place as it permits to systematically improve policies and practices for an effective preservation of the environment. The aim of this article is to provide a critical perspective on learning processes in adaptive governance. We aim at reintroducing two blind spots. First, knowledge theory frequently forget to consider the strategic issue of knowledge. Second, knowledge theory implicitly recognizes that an actor acts but, it is often true that an actor can «be acted».
ESEE 2013 - Ecological Economics and Institutional Dynamics - 10th International Conference of the European Society for Ecological Economics
Lille, France

hal-01195358
https://hal.archives-ouvertes.fr/hal-01195358
PRODINRA : 226906

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

Éditeur(s) : Wiley-blackwell
Résumé : 1. Abiotic and biotic variables of coastal lagoons are highly heterogeneous in both space and time, and this heterogeneity complicates the assessment of their ecological status. These variables are essential to the monitoring and preservation of these fragile ecotones and the resources and services they sustain. 2. An integrative approach for evaluating the ecological status of coastal lagoons, based on field investigations of the key parameters driving their functioning and a set of selected ecological indicators matching lagoon management information needs for societal benefits, is investigated. Consistency in lagoon status evaluation from multiple and different variables was estimated, through a case study comparing three adjacent yet contrasting French Mediterranean shallow water lagoons. 3. French Mediterranean shallow water lagoons are used to demonstrate the potential of such an approach and to underline the need for a multi-faceted framework, for correctly evaluating lagoon status, and underlining the need for high-frequency lagoon monitoring to avoid errors in status assessment and resulting management plans. 4. Based on the results, a continuous monitoring system is proposed that would record high frequency biotic and abiotic data in the lagoons. The use of such an ad hoc observatory system, based on appropriate diagnostic indicators and risk estimators would simplify interactions between scientists and managers and would improve the efficiency of their analyses. 5. A lagoon management plan based on a holistic approach is proposed to help scientists and local managers to reach a consensus about the set of ecological indicators to monitor in the lagoons needed to assess their global health status in accordance with both conservation and/or societal needs. Copyright (c) 2011 John Wiley & Sons, Ltd.
Aquatic Conservation-marine And Freshwater Ecosystems (1052-7613) (Wiley-blackwell), 2011-11 , Vol. 21 , N. 7 , P. 728-742

Droits : 2011 John Wiley & Sons, Ltd.
http://archimer.ifremer.fr/doc/00056/16702/14202.pdf
DOI:10.1002/aqc.1231
http://archimer.ifremer.fr/doc/00056/16702/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The lithospheric mantle is intrinsically heterogeneous and anisotropic. These two properties govern the repartition of deformation, controlling intraplate strain localization and development of new plate boundaries. Geophysical and geological observations provide clues on the types, ranges, and characteristic length scales of heterogeneity and anisotropy in the lithospheric mantle. Seismic tomography points to variations in geothermal gradient and hence in rheological behavior at scales of hundreds of km. Seismic anisotropy data substantiate anisotropic physical properties consistent at scales of tens to hundreds of km. Receiver functions imply lateral and vertical heterogeneity at scales < 10 km, which might record gradients in composition or anisotropy. Observations on naturally deformed peridotites establish that compositional heterogeneity and Crystal Preferred Orientations (CPOs) are ubiquitous from the mm to the km scales. These data allow discussing the processes that produce/destroy heterogeneity and anisotropy and constraining the time scales over which they are active. This analysis highlights: (i) the role of deformation and reactive percolation of melts and fluids in producing compositional and structural heterogeneity and the feedbacks between these processes, (ii) the weak mechanical effect of mineralogical variations, and (iii) the low volumes of fine-grained microstructures and difficulty to preserve them. In contrast, olivine CPO and the resulting anisotropy of mechanical and thermal properties are only modified by deformation. Based on this analysis, we propose that strain localization at the plate scale is, at first order, controlled by large-scale variations in thermal structure and in CPO-induced anisotropy. In cold parts of the lithospheric mantle , grain size reduction may contribute to strain localization, but the low volume of fine-grained domains limits this effect.
ISSN: 0040-1951

hal-01277174
https://hal.archives-ouvertes.fr/hal-01277174
DOI : 10.1016/j.tecto.2015.07.026

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Le tourisme de masse ayant déjà démontré ses limites et fait l’objet de critiques et d’indignation de la part des associations internationales de la protection de l’environnement cède peu à peu sa place au tourisme durable. Ce dernier tient compte de la protection de l’environnement et de la sauvegarde des richesses naturelles en offrant aux touristes des produits purement bio et des cultures tout à fait originales.Dans un contexte connu par sa complexité, vu les inégalités environnementales et sociales que connaît le Maroc, et pour remédier ce déséquilibre des acteurs économiques, des locaux dans la majorité des cas, ont opté pour des investissements touristiques dans les milieux ruraux. Ainsi des établissements touristiques ruraux commencent à prendre de l’ampleur, visant à consolider la notion du tourisme durable avec ses produits artisanaux locaux, ses variétés culinaires régionales et ses folklores saisonniers aux traditions bien enracinées. Mais ces actions sont-elles en mesure d’assurer un avenir prometteur à ces établissements ruraux, sans l’intervention de l’État qui a un rôle primordial à jouer en la matière de la formation et la qualification des ressources humaines dans le secteur du tourisme ; une formation pour préserver l’environnement et les ressources naturelles et donner un nouvel élan au tourisme rural dont la modernité demeure une référence essentielle.Par la beauté naturelle de leurs sites, la qualité de leurs aliments, le comportement clair et limpide de leurs personnes, les établissements d’hébergements touristiques ruraux marocains attirent déjà un nombre significatif de touristes qui viennent à l’origine pour un séjour de deux ou trois jours et prolongent souvent à une semaine séduits par la qualité du séjour. Eau pure, qualité de l’air, richesse culturelle, autant d’atouts qui justifient le soutien de ce genre de tourisme qui inspire notre enquête au niveau de la commune rurale d’Asni.
It is high people admitted that mass tourism has its limits as there have been consequences. Indeed several NGOS as well as international organizations aiming at the protection of the environment see that this destructive or harmful tourism is losing ground it is being substituted or replaced by eco-friendly tourism. This latter target the preservation of mother earth as well as its natural resources by providing a new type of tourism labeled rural tourism whose first and paramount objective is providing tourists with organic products. This green or rural tourism tries at all cost to promote artistic commodities, authentic cultures and purely traditional folk.Rural tourism is actually expecting more prosperity and progress but on condition that the local authorities and the government cooperate more to give a push to this kind of business via a perfect or division of human resources. Rural tourism represent a new image of modern tourism that aims to protect the environment and diversity. From the beauty of the natural land scape, the quality of the food served, the professionalism of the staff members the touristic accommodation units based in Moroccan countryside manage to attract a significant number of tourists, who often come for 2 or 3 days prolong their stay for a week for having fond a deep pleasure. The water is pure, the atmospheric air is filtered, the cultural wealth is vast, it is therefore appropriate to sustain and support this kind of tourism that inspires our investigation at the rural town of Asni.
Maroc
Asni

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.7638
http://journals.openedition.org/etudescaribeennes/7638