Éditeur(s) : CNEXO
Résumé : This book constitutes the first of a series of three volumes, the purpose of which is to cover the principal methods used in fish population dynamics. It is devoted to the definition of the main concepts, ami the presentation of the usual mathematical models. The second volume will deal with the fitting of the models, and the estimation of parameters. The third will be devoted to sampling problems. These volumes will be recollections of communications presented during ad hoc seminars, hold in Brest (GSG/COB) in 1980 and 1981. The first part deals with the basic concepts related to the two components whose relationship is being described by the population dynamics, namely the fish stock, to its relations with biological populations, and to the partition of catchabtiity into its components (vulnerability, availability...). The second chapter of this part is devoted to the quantification of exploitation. This leads to a discussion of nominal and effective fishing effort and fishing intensity. A brief review of the use of catch per unit of effort as an index of abundance is followed by a discussion of the concept of fishing power. The second part starts with some general remarks on mathematical modelling (chapter III), then comes to the two classical categories of models : global (surplus production) models (chapter IV), and structural models (chapter V). Chapter IV is mainly a review, based upon the SCHAEFER and PELLATOMLINSON models. Some less classical formulas from the recent literature are also introduced. Attention is paid to the underlying hypotheses and to the limitation of such models. The reader is finally referred to papers presenting the developments that could make it possible to overcome some of these limitations. Chapter V is based upon the classical BEVERTON and HOLT and RlCKER models, and the yield per recruit concepts. This field is however inlarged. Other commonly used variants of structural models are presented with an effort being made to clarify the real differences between all these variants. Special attention is also paid to so-called regenerative models and to the use of spawing-biomass or fecundity per recruit, which are likely to become commonly used in the coming years. In all cases, special attention is paid to the presentation of the basic formulas, that the reader might have to use if faced with a practical problem. Finally, a discussion of the underlying hypotheses takes place, before a brief review of the main developments, where the reader is referred to the appropriate literature.
Ce livre constitue le premier volet d'un tryptique destiné à effectuer une revue des méthodes essentielles en dynamique des populations marines exploitées. Il est consacré à la définition des concepts de base, à la présentation des modèles courants. Dans la discussion des concepts, ce volume s'attache à clarifier les notions relatives aux deux parties dont les relations font l'objet de la dynamique des populations exploitées : le stock et la flottille de pêche. Ceci amène notamment à préciser la définition d'un stock, sa relation avec la notion de population biologique, à analyser les problèmes de définition de la capturabilité. Les concepts d'intensité, d'effort, de puissance de pêche, une analyse des relations entre abondance et capture par unité d'effort sont ensuite présentés. Après une brève réflexion générale sur la modélisation, la deuxième partie de cet ouvrage présente les modèles eux-mêmes, en abordant successivement les modèles dits globaux et structuraux. Un effort est fait pour couvrir non seulement les versions les plus anciennes, mais aussi les variantes récentes, pour détailler les relations entre ces différentes variantes, offrir un formulaire de base, enfin, discuter les hypothèses majeures et les prolongements souhaitables ou en cours.
Publications du C.N.E.X.O. Série "Rapports scientifiques et techniques" (0339-2899) (CNEXO), 1981 , N. 45 , P. 1-120

Droits : Centre National pour l'Exploitation des Océans, 1981
http://archimer.ifremer.fr/doc/1981/rapport-1126.pdf
http://archimer.ifremer.fr/doc/00000/1126/

Éditeur(s) : HAL CCSD
Résumé : International audience
Here, we synthesize conceptual frameworks, applied modeling approaches, and as case studies to highlight complex social-ecological system (SES) dynamics that inform environmental policy, conservation and management. Although a set of “good practices” about what constitutes a good SES study are emerging, there is still a disconnection between generating SES scientific studies and providing decision-relevant information to policy makers. Classical single variable/hypothesis studies rooted in one or two disciplines are still most common, leading to incremental growth in knowledge about the natural or social system, but rarely both. The recognition of human dimensions is a key aspect of successful planning and implementation in natural resource management, ecosystem-based management, fisheries management, and marine conservation. The lack of social data relating to human-nature interactions in this particular context is now seen as an omission, which can often erode the efficacy of any resource management or conservation action. There have been repeated calls for a transdisciplinary approach to complex SESs that incorporates resilience, complexity science characterized by intricate feedback interactions, emergent processes, non-linear dynamics and uncertainty. To achieve this vision, we need to embrace diverse research methodologies that incorporate ecology, sociology, anthropology, political science, economics and other disciplines that are anchored in empirical data. We conclude that to make SES research most useful in adding practical value to conservation planning, marine resource management planning processes and implementation, and the integration of resilience thinking into adaptation strategies, more research is needed on (1) understanding social-ecological landscapes and seascapes and patterns that would ensure planning process legitimacy, (2) costs of transformation (financial, social, environmental) to a stable resilient social-ecological system, (3) overcoming place-based data collection challenges as well as modeling challenges.
Ocean and Coastal Management

Droits : http://creativecommons.org/licenses/by-nc-nd/
hal-01224152
https://hal-univ-perp.archives-ouvertes.fr/hal-01224152
https://hal-univ-perp.archives-ouvertes.fr/hal-01224152/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01224152/file/1-s2.0-S096456911500126X-main.pdf
DOI : 10.1016/j.ocecoaman.2015.04.018

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Le tourisme est souvent présenté comme l’un des instruments d’un développement durable, même s’il connaît une expansion difficilement maîtrisable, au détriment du patrimoine environnemental, insulaire et littoral en particulier, comme dans les DOM-TOM.Le tourisme a des impacts, culturels et sociaux notamment, sur l’environnement. Les ressources du patrimoine alimentent de leur côté la demande et l’offre touristiques. Un tourisme assis sur une gestion ad hoc des ressources du patrimoine constitue un facteur puissant de durabilité du développement local. La soumission de l’activité touristique aux exigences de protection, de conservation et de gestion reproductible de la biodiversité et du patrimoine naturel, dans les aires protégées de la Caraïbe française en particulier, génère des approches, des stratégies et des comportements nouveaux. La démarche écotouristique appelle une gestion participative et intégrée des ressources et des espaces, et constitue un défi pour les opérateurs du tourisme comme pour les acteurs de l’environnement, et une opportunité de « réappropriation » de leur milieu de vie par les populations locales. Il faut alors en clarifier le concept et les implications ; puis en analyser les objectifs et les enjeux dans une perspective de développement durable.
Tourism often appears as one a tool for a sustainable development, even if it is not easy to control, in the détriment of island and costal environment heritage, as in French overseas regions. Besides the cultural and social impacts of tourism upon environment, the heritage resources nuture the touristic request and offer. If based on an appropriate management of those resources, it may be a strong incentive for local sustainable development. The respect of protection, conservation and sustainable management of biodiversity and natural resources by tourism, especially in the overseas regions of French West Indies, produces new approaches, strategies and behaviours. The ecotourism approach, calling for a joint and integrated management of resources and areas, is a challenge for tour operators as for environment actors, and brings local population an opportunity to reappropriate their life environment. Its concept and implications must then be clarified, before analysing its aims and stakes regarding sustainable development
Caraïbes

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.3560
http://journals.openedition.org/etudescaribeennes/3560

Éditeur(s) : Elsevier Science Bv
Résumé : Sustainable management of natural resources, and in particular fisheries, must take into account several conflicting objectives. This is the case in the French Guiana shrimp fishery for which profitability objectives imply a reduction in the fishing activity. On the one hand, this fishery has negative externalities on marine biodiversity due to discards. On the other hand, this fishery has positive externalities on the economy of the local community and interestingly enough on a protected seabird species in the area (the Frigatebird that feeds on discards). In this paper, we examine the viability of that system considering two sustainability objectives: an economic objective in terms of the profitability of the fishing activity, and a conservation objective in terms of the Frigatebird population. For that purpose, we have developed a dynamic model of that bioeconomic system and study here the trade-offs between the two conflicting objectives. It provides a means to quantify the necessary give and takes involving the economic and ecological objectives that would ensure a viable management solution. Our study confirms the relevance of the viability approach to address natural resource management issues, which should lead to the development of new tools for the arbitration of conflicting sustainability, objectives. In particular, such tools could be used as a quantitative basis for cost-benefit analysis taking into account environmental externalities. (C) 2009 Elsevier B.V. All rights reserved.
Ecological Economics (0921-8009) (Elsevier Science Bv), 2009-10 , Vol. 68 , N. 12 , P. 2960-2968

Droits : 2009 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/00020/13135/10195.pdf
DOI:10.1016/j.ecolecon.2009.06.012
http://archimer.ifremer.fr/doc/00020/13135/

Éditeur(s) : HAL CCSD Ecole nationale du génie rural
Résumé :  
Le patrimoine forestier guyanais, exceptionnel et riche, est placé dans un contexte humain singulier qui l'a, jusqu'à présent, relativement épargné. Domaine privé de l'État, il est géré par l'Office national des Forêts qui y intervient en conservation et mise en valeur durable. Outre la zone littorale qui recèle encore des milieux naturels, on y distingue une zone sublittorale de forêts aménagées, un massif intérieur avec de nombreux espaces protégés, enfin des zones de droit d'usage au bénéfice des communautés tirant traditionnellement de la forêt leurs moyens de subsistance. Dans les forêts aménagées, on s'oriente de plus en plus vers une sylviculture extensive, avec un recours limité à la plantation, prévenant les conflits d'usage. Il s'agit maintenant d'adopter une loi et des orientations régionales forestières, de redéfinir les modalités d'élaboration des aménagements, d'écocertifier la forêt guyanaise, d'adapter les modes de commercialisation et d'exploitation des bois, de mieux valoriser la ressource forestière.
ISSN: 0035-2829

hal-01032192
https://hal.archives-ouvertes.fr/hal-01032192

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
As climate change continues to impact socio-ecological systems, tools that assist conservation managers to understand vulnerability and target adaptations are essential. Quantitative assessments of vulnerability are rare because available frameworks are complex and lack guidance for dealing with data limitations and integrating across scales and disciplines. This paper describes a semi-quantitative method for assessing vulnerability to climate change that integrates socio-ecological factors to address management objectives and support decision-making. The method applies a framework first adopted by the Intergovernmental Panel on Climate Change and uses a structured 10-step process. The scores for each framework element are normalized and multiplied to produce a vulnerability score and then the assessed components are ranked from high to low vulnerability. Sensitivity analyses determine which indicators most influence the analysis and the resultant decision-making process so data quality for these indicators can be reviewed to increase robustness. Prioritisation of components for conservation considers other economic, social and cultural values with vulnerability rankings to target actions that reduce vulnerability to climate change by decreasing exposure or sensitivity and/or increasing adaptive capacity. This framework provides practical decision-support and has been applied to marine ecosystems and fisheries, with two case applications provided as examples: (1) food security in Pacific Island nations under climate-driven fish declines, and (2) fisheries in the Gulf of Carpentaria, northern Australia. The step-wise process outlined here is broadly applicable and can be undertaken with minimal resources using existing data, thereby having great potential to inform adaptive natural resource management in diverse locations.
ISSN: 0308-597X

hal-01380403
https://hal-univ-perp.archives-ouvertes.fr/hal-01380403
DOI : 10.1016/j.marpol.2016.09.024

Résumé : Marine capture fisheries in Jamaica is primarily artisanal in nature ansd is conducted maiinly by fishermen operating from canoes. Approximately 95% of these fishermen operate on the coastal shelf and its associated banks. The commercial species harvested comprise bottom-dwelling, coral reef species and free swimming species of finfish. Other fishery resources of commercial value include marine shrimp, conch and lobsters. Catch statistics are not available for all species, but the Department of Fisheries reports a slight decline in fishery production with production decreasing from 16 milion lbs in 1990, despite the fact that fishing efforts have doubled. Over this period the number of registered fishermen has grown from 12 000 to 16 000, al of whom are engaged in full-time fishing. There arealso part-time fishermen who are not registered. The decline in fish catch is accompanied by a decrease in fish size and quality, suggesting that the fisheries are under pressure and have already exceeded optimum production in relation to vailable resources. As a result the economic returns to fishermen are declining. There are also other problems, such as high incidence of conflicts among fishermen at sea, the high cost of purchasing boats, outboard engine fuel, and equipment, with together with the dangers involved in fishing offshore (piracy, and praedial larceny) create serious social ans economic difficulties for fishermen. Notwithstanding, there is an apparent move on the part of the fishermen to leave the industryor to seek alternative forms of employment. In fact, the Department ofFisheries reports that it is still reciving applications for new licences to operate fishing boats. This is probably due to the fact that where the basis of a community is fishing, it becomes difficult to introduce alternative forms of employment, such as cottage industries, village crafts and other trades. In 1987 the Jamaica Department of Fisheries prepared a Management plan which proposed several conservation measures to promote the efficient use of fisheries resources and to control the development of the Fishery in such a way that the country would receive highest benefits. Adequate attention was given to limitations on fishing gear, institution of closed seasons and related legislation. Strategies to diversify the marine fishing were also proposed. The 1990 five year Devlopment Plan for marine fisheries also focuses on proper resource management in order to reverse trends associated with the overexploitation of marine resources. According to the plan, emphasis will be placed on inland fisheries and mariculture in order to reduce pressure on the fisheries. Inland fisheries in the form of freshwater fish fanning has expanded significantly over the past 10 years with production increasing from less than 0,5 million lbs. in 1980 to in excess of 6.0 million lbs. in 1989. However, some freshwater fish farmers are already experiencing serious competition for water usage and, to a lesser extent for land from crop-producing farmers. The Ministry of Agriculture is of the view that marine cage culture technologically has the potential for introduction in Jamaica . This technologyhas been successfully developed in Norway and the technology is currentlty being experimentally utilized in several countries in the area. The technology, if widely utilized in Jamaica, couls significantly reduce pressure on fisheries, making fishing more cost effective and improve the economic returns to fishermen. Already there exist some technical and institutional capabilities in Jamaica to support commercial development of marine cage culture. The Department of Fisheries has highly trained personnel in aquaculture and marine fisherie, some of whom are directly responsible for the success of freshwater fish fanning. In adition, the Marine Laboratory at the Univesity of the West Indies (UWI) is caarying research on hatchery facilities for marine cage farming. The Department of Fisheries will seek the collaboration ofg the marine unit at UWI which could provide fingerlings of selected marine species for cage 1
Les pêcheries de captage marin en Jamaïque sont principalement de nature artisanale et elles sont dirigées principalement par les pêcheurs qui travaillent depuis des canoës. Environ 95 % de ces pêcheurs travaillent sur la plaine côtière et ses bancs associés. Les espèces commerciales récoltées comprennent les espèces benthiques, les espèces de corail et les espèces de poisson marin de nage libre. D'autres ressources de pêcheries de valeur commerciale comprennent la crevette, la conque et le homard. Les statistiques des pêches ne sont pas disponibles pour toutes les espèces, mais le Département des Pêcheries fait état d'une légère réduction de production de pêcheries, la production se réduisant de 16 millions de livres en 1990, en dépit du fait que les efforts de la pêche ont doublé. Sur cette période le nombre de pêcheurs inscrits a augmenté de 12 000 à 16 000, dont tous sont occupés à plein temps à la pêche. Il y a aussi des pêcheurs à mi-temps qui ne sont pas inscrits. La réduction des pêches est accompagnée d'une réduction de la taille et la qualité des poissons, ce qui implique que les pêcheries sont sous pression et qu'elles ont déjà dépassé la production optimum par rapport aux ressources disponibles. En conséquence, les rendements pour les pêcheurs sont en baisse. Il y a aussi d'autres problèmes, tels qu'un taux élevé de conflits entre les pêcheurs en mer, le coût élevé pour acheter les bateaux, le combustible pour les moteurs hors-bord, et le matériel, ainsi que les dangers impliqués dans la pêche offshore (le piratage, et le vol prédial) ont créé de graves problèmes sociaux et économiques pour les pêcheurs. Néanmoins, il y a une tendance évidente chez les pêcheurs de quitter l'industrie ou de chercher du travail dans d'autres domaines. En fait, le Département des Pêcheries signale qu'il continue de recevoir des demandes de nouveaux permis pour opérer les bateaux de pêche. Ceci est probablement attribuable au fait que là où la base d'une communauté est la pêche, il est difficile d'y introduire des formes alternatives de travail, telles que l'industrie artisanale, l'artisanat de village ou d'autres métiers. Le Département des Pêcheries de la Jamaïque a préparé en 1987 un Projet de gestion qui proposait plusieurs mesures de conservation afin d'encourager l'utilisation efficace des ressources des pêcheries et de contrôler le développement de la Pêcherie de manière que le pays touche le plus de bénéfices. Une attention adéquate a été prêtée aux limitations sur les engins de la pêche, l'établissement de saisons de clôture et les législations associées. Des stratégies pour diversifier la pêche marine ont aussi été proposées. Le Plan de développement quinquennal de 1990 pour les pêcheries marines met l'accent aussi sur la gestion de ressources appropriée afin de faire reculer les tendances associées à la surexploitation des ressources marines. Selon le plan, l'accent sera mis sur les pêcheries intérieures et la mariculture afin de réduire la pression sur les pêcheries. Les pêcheries intérieures, sous la forme de l'élevage de poissons en eau douce, ont pris leur essor sur les 10 dernières années avec une production qui s'est élevée de moins de 0,5 millions de livres en 1980 pour atteindre en 1989 plus de 6.0 millions de livres. Cependant, certains pisciculteurs en eau douce expérimentent déjà une concurrence sérieuse avec les agriculteurs pour l'usage de l'eau et, dans une moindre mesure, de la terre. Le Ministère de l'Agriculture est de l'avis que l'élevage en cage marine a technologiquement le potentiel d'être introduit en Jamaïque. La technologie a été développée avec réussite en Norvège et plusieurs pays dans la région utilisent actuellement la technologie expérimentalement. La technologie, si elle était utilisée en Jamaïque, pourrait réduire de façon significative la pression sur les pêcheries, ce qui rendrait la pêche plus économique et améliorerait les rendements aux pêcheurs. Certaines capacités techniques et institutionnelles existent déjà en Jamaïque qui pourraient soutenir le développement de l'élevage en cage marine. Le Département des Pêcheries a un personnel bien formé en aquaculture et pêcherie marine, dont certains qui sont directement responsables du succès de la pisciculture en eau douce. Par ailleurs, le Laboratoire Marin à l'Université des Antilles (UWI) mène des recherches sur les installations d'écloseries pour l'élevage en cage marine. Le Département des Pêcheries demandera la collaboration de l'unité marine à l'UWI qui pourra fournir des saumoneaux d'espèces marines sélectionnées pour la cage 1.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1993/rapport-1918.pdf
http://archimer.ifremer.fr/doc/00000/1918/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : La présente étude a été menée dans les cantons de la préfecture de Doufelgou au Nord Togo. Sur la base de la beauté du paysage, des richesses naturelles et des enquêtes semi-structurées, le potentiel écotouristique de cette préfecture a été évalué. Le traitement des données spatiales collectées a permis de réaliser la carte écotouristique et de proposer un circuit touristique. Trois catégories de potentialités ont été répertoriées : les potentialités naturelles, les potentialités culturelles et les potentialités anthropiques. Ces potentialités peu valorisées subissent à des degrés variables diverses pressions susceptibles de les mettre en péril. Cet article présente ces diverses potentialités et analyse les opportunités socio-économique et environnementale d’un développement écotouristique dans cette zone.
This study was conducted in the cantons of Doufelgou prefecture in Northern Togo. On the basis of the beauty of the landscape, natural resources and semi-structured surveys, the potential ecotourism in this prefecture was evaluated. The treatment of spatial data collected helped make ecotourism map and to propose a tourist circuit. Three categories of potential have been identified: the natural potential, cultural potential and human potential. These potentialities are little valued and suffer to varying degrees various pressures which may put them at risk. This paper presents various potential and carries an analysis on socio-economic and environmental benefits of ecotourism development in this area.
Doufelgou
Togo

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.6326
http://journals.openedition.org/etudescaribeennes/6326

Éditeur(s) : HAL CCSD
Résumé : This paper studies the implications of fi…sh search activities on the working of …fisheries. We develop a simple …shery matching modelin which …rms’ stochastic search for …sh requires speci…fic resources.The equilibrium level of anthropic pressure (number of empty ves-sels/conserved …sh stock) exerted by …rms on the …sh stock is derivedfrom their individual pro…t maximizing behavior. Anthropic pressuredetermines in turn the rate at which vessels fi…nd fi…sh i.e. catchability,which is therefore endogenous in our model, and the stock conserva-tion (uncaught …sh) rate, through the dynamic equation of the latter.We then show that under open access, equilibrium anthropic pressure,…fishing effort and the conservation rate heavily depend on search costs.An empirical study of the French Guiana shrimp …shery con…rms theability of the model to reproduce empirical data.
https://hal.univ-antilles.fr/hal-01228851

Droits : info:eu-repo/semantics/OpenAccess
hal-01228851
https://hal.univ-antilles.fr/hal-01228851
https://hal.univ-antilles.fr/hal-01228851/document
https://hal.univ-antilles.fr/hal-01228851/file/Nicolas%20Sanz%20%26Bassirou%20Diop.pdf

Éditeur(s) : Public Library Science
Résumé : The European Union and other states are moving towards Ecosystem Based Fisheries Management to balance food production and security with wider ecosystem concerns. Fishing is only one of several sectors operating within the ocean environment, competing for renewable and non-renewable resources that overlap in a limited space. Other sectors include marine mining, energy generation, recreation, transport and conservation. Trade-offs of these competing sectors are already part of the process but attempts to detail how the seas are being utilised have been primarily based on compilations of data on human activity at large spatial scales. Advances including satellite and shipping automatic tracking enable investigation of factors influencing fishers' choice of fishing grounds at spatial scales relevant to decision-making, including the presence or avoidance of activities by other sectors. We analyse the determinants of English and Welsh scallop-dredging fleet behaviour, including competing sectors, operating in the eastern English Channel. Results indicate aggregate mining activity, maritime traffic, increased fishing costs, and the English inshore 6 and French 12 nautical mile limits negatively impact fishers' likelihood of fishing in otherwise suitable areas. Past success, net-benefits and fishing within the 12 NM predispose fishers to use areas. Systematic conservation planning has yet to be widely applied in marine systems, and the dynamics of spatial overlap of fishing with other activities have not been studied at scales relevant to fisher decision-making. This study demonstrates fisher decision-making is indeed affected by the real-time presence of other sectors in an area, and therefore trade-offs which need to be accounted for in marine planning. As marine resource extraction demands intensify, governments will need to take a more proactive approach to resolving these trade-offs, and studies such as this will be required as the evidential foundation for future seascape planning.
Plos One (1932-6203) (Public Library Science), 2015-01-27 , Vol. 10 , N. 1 , P. 1-14

Droits : 2015 Tidd et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
http://archimer.ifremer.fr/doc/00254/36518/35064.pdf
DOI:10.1371/journal.pone.0116335
http://archimer.ifremer.fr/doc/00254/36518/

Éditeur(s) : HAL CCSD Cambridge University Press (CUP)
Résumé :  
Although the potential contribution to tropical tree species coexistence of niche differentiation along light gradients has receivedmuch attention, the degree to which species perform differentially along soil resource gradients remains unclear. To examine differential growth response to soil resources, we grew seedlings of nine tropical tree species at 6.0% of full sun for 12mo in a factorial design of two soil types (clay and white sand), two phosphate fertilization treatments (control and addition of 100mgP kg−1) and two watering treatments (field capacity and water limitation to one-third field capacity). Species differedmarkedly in biomass growth rate, but this hierarchy was almost completely conserved across all eight treatments. All species grew more slowly in sand than clay soils, and no species grew faster with phosphate additions. Only Eperua grandiflora and E. falcata showed significant growth increases in the absence of water limitation. Faster-growing species were characterized by high specific leaf area, high leaf allocation and high net assimilation rate but not lower root allocation. Slower-growing species exhibited greater plasticity in net assimilation rate, suggesting that tolerance of edaphic stress in these species is related more to stomatal control than to whole-plant carbon allocation. Although relative growth rate for biomass was correlatedwith both its physiological and morphological components, interspecific differences were best explained by differences in net assimilation rate across six of the eight treatments. A suite of traits including high assimilation and high specific leaf area maintains rapid growth rate of faster-growing species across awide gradient of soil resources, but the lack of plasticity they exhibit may compromise their survival in the poorest soil environments.
ISSN: 0266-4674

hal-01032086
https://hal.archives-ouvertes.fr/hal-01032086
DOI : 10.1017/S0266467406003439

Éditeur(s) : HAL CCSD Wiley/Blackwell
Résumé : International audience
Marine fishes exhibit spectacular phenotypic changes during their ontogeny, and the identification of their early stages is challenging due to the paucity of diagnostic morphological characters at the species level. Meanwhile, the importance of early life stages in dispersal and connectivity has recently experienced an increasing interest in conservation programmes for coral reef fishes. This study aims at assessing the effectiveness of DNA barcoding for the automated identification of coral reef fish larvae through large-scale ecosystemic sampling. Fish larvae were mainly collected using bongo nets and light traps around Moorea between September 2008 and August 2010 in 10 sites distributed in open waters. Fish larvae ranged from 2 to 100 mm of total length, with the most abundant individuals being <5 mm. Among the 505 individuals DNA barcoded, 373 larvae (i.e. 75%) were identified to the species level. A total of 106 species were detected, among which 11 corresponded to pelagic and bathypelagic species, while 95 corresponded to species observed at the adult stage on neighbouring reefs. This study highlights the benefits and pitfalls of using standardized molecular systems for species identification and illustrates the new possibilities enabled by DNA barcoding for future work on coral reef fish larval ecology.
ISSN: 1755-098X

hal-01342973
https://hal-univ-perp.archives-ouvertes.fr/hal-01342973
DOI : 10.1111/1755-0998.12293

Éditeur(s) : Elsevier
Résumé : Overexploitation of marine resources remains a problem worldwide. Many works advocate for the use of marine reserves as a central element of future stock management in a sustainable perspective. In the present paper, we address the influence of protected areas upon fisheries sustainability within an eco-systemic framework through a dynamic bio-economic model integrating a trophic web, catches and environmental uncertainties. The model is spatially implicit. The evaluation of the ecosystem is designed through the respect along time of constraints of both conservation and guaranteed captures. Using the mathematical concept of invariance kernel in a stochastic context, we define different MPA effects according to biodiversity catches or mixed points of view. Numerical simulations inspired from data of Abore coral reef reserve in New Caledonia illustrate the main concepts. In this case, it is pointed out how MPA conservation effect is not necessarily conflicting with MPA catches effect. it is shown that such a co-viability requires medium exploitation rate. Moreover, the climatic changes represented by rise in cyclonic events seem to reinforce these assertions. (C) 2007 Elsevier B.V. All rights reserved.
Ecological Modelling (0304-3800) (Elsevier), 2007-11 , Vol. 208 , N. 2-4 , P. 353-366

Droits : 2007 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2007/publication-3510.pdf
DOI:10.1016/j.ecolmodel.2007.06.018
http://archimer.ifremer.fr/doc/00000/3510/

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) : Université des Antilles Études caribéennes
Résumé : Cet article propose d’explorer les enjeux politiques et économiques auxquels sont confrontés les acteurs du développement touristique à Madagascar. S’appuyant sur une approche hétérodoxe d’économie politique, notre analyse cherche à identifier les mécanismes d’arbitrage entre les objectifs de développement du tourisme, de lutte contre la pauvreté et ceux de protection des ressources naturelles, particulièrement dans le cas du Parc National d’Andohahela dans la région de Tolagnaro (Sud-est de Madagascar). Les enjeux sous-jacents et l’urgence des conditions qui caractérisent Madagascar militent en faveur d’un renouvellement du regard s’appuyant sur l’économie politique afin d’éclairer les perceptions et les tensions dans la définition des problèmes économiques, sociaux et environnementaux. Cette lecture permet d’identifier certaines incompatibilités qui expliquent en partie les multiples ambiguïtés dans la mise en œuvre de stratégies de protection des ressources naturelles par le développement touristique et contribue ainsi à mieux comprendre les « blocages » qu’on lui attribue.
This paper analyses some challenges facing tourism development in Madagascar. Relying on a heterodox political economy approach, our analysis seeks to better understand dialectical relationship between tourism development objectives, the fight against poverty and the natural resources conservation, particularly in the case of Andohahela National Park in Tolagnaro region (South-eastern Madagascar). The underlying issues that characterize Madagascar suggest for are newed analytical framework based on political economy to clarify perceptions related to economic, social and environmental problems. This process contributes to clarify the several ambiguities of tourism based conservation strategies and seeks to better understand implementation setback.
Madagascar
Tolagnaro

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.6557
http://journals.openedition.org/etudescaribeennes/6557

Éditeur(s) : HAL CCSD
Résumé : International audience
Semantic web standards, tools, ontologies and related technologies have considerably matured in the recent years. Nowadays, accessing a wide catalogue of biological, social, environmental, and ecological data sources helps stakeholders working on biodiversity to answer their complex questions. Will the real time access to web resources effectively support the definition of strategies to conserve and manage biodiversity? How might semantic web technologies help us to handle the complex and heterogeneous big data related to biodiversity? The workshop aims to identify the key challenges faced by the bioinformatics community, discuss potential solutions and identify the opportunities emerging from the trans-disciplinary interactions between Plant Science and Informatics experts. Therefore, we expect the bioinformatics experts to explain how they apply semantic web standards and tools to their scientific topic, from biology, agriculture, agro-ecology, genomics, environmental studies, to social sciences, citizen sciences. Research papers presenting various aspects of semantic web technologies applied to biodiversity data, ranging from position papers to implemented systems descriptions and their evaluation, will be selected. We are particularly interested in the use of the semantic technologies to design and develop systems that supports research on agricultural and wild biodiversity conservation and management for food security. Examples may include strategies for resilience to climate change pressures, sustainability of productive ecosystems, ecosystems services monitoring or territories management, rather than systems supporting only research on climate patterns or soil erosion.
http://hal-lirmm.ccsd.cnrs.fr/lirmm-00831757

lirmm-00831757
http://hal-lirmm.ccsd.cnrs.fr/lirmm-00831757
http://hal-lirmm.ccsd.cnrs.fr/lirmm-00831757/document

Éditeur(s) : HAL CCSD Society for Molecular Biology and Evolution
Résumé : International audience
Although heterokaryons have been reported in nature, multicellular organisms are generally assumed genetically homogeneous. Here, we investigate the case of arbuscular mycorrhizal fungi (AMF) that form symbiosis with plant roots. The growth advantages they confer to their hosts are of great potential benefit to sustainable agricultural practices. However, measuring genetic diversity for these coenocytes is a major challenge: Within the same cytoplasm, AMF contain thousands of nuclei and show extremely high levels of genetic variation for some loci. The extent and physical location of polymorphism within and between AMF genomes is unclear. We used two complementary strategies to estimate genetic diversity in AMF, investigating polymorphism both on a genome scale and in putative single copy loci. First, we used data from whole-genome pyrosequencing of four AMF isolates to describe genetic diversity, based on a conservative network-based clustering approach. AMF isolates showed marked differences in genome-wide diversity patterns in comparison to a panel of control fungal genomes. This clustering approach further allowed us to provide conservative estimates of Rhizophagus spp. genomes sizes. Second, we designed new putative single copy genomic markers, which we investigated by massive parallel amplicon sequencing for two Rhizophagus irregularis and one Rhizophagus sp. isolates. Most loci showed high polymorphism, with up to 103 alleles per marker. This polymorphism could be distributed within or between nuclei. However, we argue that the Rhizophagus isolates under study might be heterokaryotic, at least for the putative single copy markers we studied. Considering that genetic information is the main resource for identification of AMF, we suggest that special attention is warranted for the study of these ecologically important organisms.
ISSN: 1759-6653

Droits : http://creativecommons.org/licenses/by/
hal-01224215
http://hal.upmc.fr/hal-01224215
http://hal.upmc.fr/hal-01224215/document
http://hal.upmc.fr/hal-01224215/file/Genome%20Biol%20Evol-2015-Boon-505-21.pdf
DOI : 10.1093/gbe/evv002

Éditeur(s) : HAL CCSD Société nationale de protection de la nature
Résumé : International audience
The island of Moorea in French Polynesia is representative of a relatively well preserved small tropical oceanic island but both its terrestrial and marine ecosystems are currently under strong anthropogenic pressures. The terrestrial ecosystems are facing an increasing urbanization, and the destruction and modification of their natural habitats by cultivation and forestry plantations, accidental or intentional fires, and particularly by the invasion of alien plant and animal species. Coastal areas and reef ecosystems are threatened by shoreline artificialization, sedimentation due to soil erosion, increasing uses of marine and lagoon resources and frequency of coral bleaching events. A significant erosion of terrestrial and marine biodiversity is observed on the island since the last decades. In the context of the Land Management Plan (PGA) and Marine Area Management Plan (PGEM) recently set up in the island by local authorities, scientific surveys and inventories were made in 2006 in order to assess the status of terrestrial biodiversity (vascular plants) and marine biodiversity (reef fishes) and compare areas with different anthropogenic pressures. Studies conducted on the flora and the vegetation at low and middle elevation along altitudinal transects show that the plant invasion process is related to climatic and topographic factors, and species autoecology. The marine study aims to compare the protected areas with control areas in order to test the effectiveness of protection measures and to propose a streamlined monitoring protocol. A methodological study in both terrestrial and marine ecosystems was conducted in order to propose biodiversity indicators which are crucial for decision making in conservation and sustainable development of island biodiversity. We used Geographic Information System (GIS) as a fast and intuitive tool for mapping indicators and their variability. This methodological approach developed on the island of Moorea could be used as a model for other tropical islands
Moorea est une petite île océanique tropicale de la Polynésie française relativement bien préservée, mais dont les écosystèmes terrestres et marins sont actuellement soumis à de fortes pressions anthropiques. Le milieu terrestre est confronté à une urbanisation croissante, à la destruction ou à la modification des habitats naturels pour l’extension des cultures ou des plantations forestières, aux incendies volontaires ou accidentels, et particulièrement à l’invasion d’espèces végétales et animales introduites. Les zones côtières et les récifs coralliens sont menacés par de multiples perturbations telles que l’artificialisation des lignes de rivage, l’apport de sédiments dus à l’érosion des sols, l’augmentation des usages des ressources marines et lagonaires et de la fréquence des phénomènes de blanchissement du corail. Une érosion sensible de la biodiversité terrestre et marine de l’île est observée depuis les dernières décennies. Dans le cadre du Plan Général d’Aménagement (PGA) et du Plan de Gestion de l’Espace Maritime (PGEM) mis en place par les autorités locales, des inventaires scientifiques ont été réalisés en 2006 dans le but d’évaluer l’état de la biodiversité terrestre (plantes vasculaires) et marine (poissons récifaux) et de comparer des zones soumises à différentes perturbations. Les études réalisées sur la flore et la végétation de basse et moyenne altitude le long de transects altitudinaux montrent des processus d’invasion végétale différents en relation avec les facteurs climatiques, topographiques et autoécologiques des espèces. Les études en milieu marin visent à comparer des aires protégées à des aires témoins afin de suivre l’efficacité des mesures de gestion. La réflexion méthodologique menée parallèlement sur les deux écosystèmes a pour but d’illustrer différents indices de biodiversité nécessaires à la prise de décision en matière de conservation ou de développement durable de la biodiversité insulaire et de réaliser un état de référence pour établir un diagnostic sur l’état de la biodiversité. La représentation cartographique des indices à l’aide d’un SIG, illustrée dans cette étude avec la richesse spécifique terrestre et marine, permet une lecture intuitive et rapide de la variabilité de cet indice dont la restitution est basée sur une standardisation du nombre d’espèces. Cette approche méthodologique développée sur l’île de Moorea pourrait servir de modèle pour d’autres îles tropicales
EISSN: 2429-6422

hal-01306285
https://hal-univ-perp.archives-ouvertes.fr/hal-01306285

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Cet article se réfère à ce que certains auteurs nomment, au Brésil, «nouveaux territoires» qui, depuis les débats lors de la Constituante fédérale de 1988, ont pris place, totalement ou partiellement, dans les circonscriptions tels qu’un État, une Commune, un District. Ce texte aborde deux types de réserves de conservation environnementale: une « réserve extractiviste » conquise par des populations rurales riveraines au confluent des fleuves Xingu et Amazone; et une « réserve marine» de populations rurales côtières – les deux à l’État du Pará. Au Brésil comme en Europe, ces initiatives ont visé un meilleur mode de vie et le développement des populations locales et, éventuellement, par surplus, régionales ou nationales. Au Brésil, ces objectifs ont été liés au droit à l’usage collectif des forêts, des bois, des cours d’eau et des mangroves. À des degrés différents, ces territoires sont issus de luttes pour la défense des ressources qui étaient la source de la subsistance de leurs habitants, de leur mode de vie et culture, en un mot, leur patrimoine – contre la pénétration d’« étrangers » venus d’ailleurs en dépit de la loi et de la légitimité: entreprises du bois, de grands élevages et de pêche. Ce texte cherche à confronter, au niveau de l’analyse sociologique, des intérêts de groupes, des acteurs, des stratégies des uns et des autres et de leurs perspectives pour les actuelles et futures générations.
This article refers to what some writers call, in Brazil, "new territories". Since the debates during the Federal Constitution elaboration, in 1988, they have been implemented, wholly or partly, within the jurisdiction of a state, a municipality, or a district. This paper addresses two types of environmental conservation reserves: an "extractive reserve" conquered by rural people at the confluence of the rivers Xingu and Amazon; and a "marine reserve" of rural populations on the northern coast of Brazil - both in the federal state of Pará. In Brazil as in Europe, these initiatives aim at better living standards and collective development of local populations. In Brazil, these have been linked to the respect of their collective rights to use the forests, wood, water streams and mangroves. To varying degrees, these territories result from struggles in defense of natural resources that were source of livelihood, lifestyle and culture of the inhabitants, in short, their heritage – against the invasion of "foreigners", timber companies, large farms and fishers. This text contrasts, through sociological analysis, the interest groups, the stakeholders, the challenges and their development prospects vis-à-vis the present and future generations.
Brésil

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.8854
http://journals.openedition.org/etudescaribeennes/8854

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Transport of liquid and gaseous hydrocarbons through focused fluid flow systems is a widespread process in continental margins and sedimentary basins, which is gaining increased attention in the assessment of geohazards, environment conservation, and securing fossil energy resources. Studying the abundance, distribution and drivers for this process is crucial for understanding its role in 1) the dynamics of gas hydrate accumulation and destabilization, 2) submarine slope stability and related tsunamis, 3) the plethora of chemosynthetic benthic ecosystems that develop in deep seep sites, and 4) the input of greenhouse gases (e.g. methane) into the ocean/atmosphere system, which may influence the atmospheric carbon budget and Earth's paleo- and present climate. New ocean exploration tools provide ever more data and improve our understanding of these systems. However, the subject still suffers from a lack of interdisciplinary knowledge dissemination. The ongoing international debate about the timing and the processes that control fluid expulsion in sedimentary basins is fuelled by their implications for structural and petroleum geology. Because fluids expelled at cold seeps originate at depth they represent open windows into the underlying petroleum systems and are valuable indicators for the reservoir systems. They may also help in deciphering past and predicting future climate change because worldwide release of large amounts of fluids may have an impact on the chemistry of the ocean and atmosphere.
ISSN: 0025-3227

hal-00772472
https://hal.archives-ouvertes.fr/hal-00772472
DOI : 10.1016/j.margeo.2012.10.012