Mise en place et exploitation des DCP en Martinique, aspects reglementaires et economiques Auteur(s) : Laisne, L Angelelli, P Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999 Résumé : Since the beginning of 1980, the Martinique fishermen have suffered a deep crisis. The traditional ways of fishing, based on benthic fish exploitation, have seen the decreasing of their profitability due to the over-fishing of the narrow continental shelf offering few resources. The pelagic fishery had become the professional main source of income. This fishery equally encounter difficulties: denied rights of access in the EEZ of Caribbean islands, expensive costs of exploitation. The disposal of FADs offers new ways to the Martinique fishermen. In 1999, it was decided the disposal of a onetworko of 30 permanent FADs around Martinique. The mooring of these FADs must be followed by legal and economic adapted measures to reach the desired aim: the development of local fishery economy through a sustainable fishing practice. Therefore, the French authorities have decided to make the regional fishermen committee responsible for the management of FADs.This committee is the only one to be entitled to moor and to deliver licences to FADs. This committee, gathering all the fishing industry representatives, has regarding the french law the right of mooring and delivering licences to the FADs access, collecting fishery statistics. These data should fund research to improve the management of the fishery, care and replace FADs. This programas realisation, as well as durability, need adequate financial planning. It has been included in the European commission financing program. This plans success will ensure the increase of the fishermen income, maintain and develop employment.Original Abstract: Apres une periode d'experimentation lancee localement au debut des annees quatre-vingt, les premiers resultats ont ete suffisamment probants pour conduire les professionnels a souhaiter l'implantation de dispositifs de concentration de poissons (dcp) en Martinique ou a les implanter eux-memes pour la capture des dorades coryphenes, des thons noirs, de l'albacore ou du listao. Le colloque international sur la peche thoniere et les dispositifs de concentration de poissons organise du 15 au 19 octobre 1999 en Martinique donne l'occasion de revenir sur le contexte, l'interet et les modalites de developpement de la technique des dcp en Martinique. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/00042/15305/12639.pdf http://archimer.ifremer.fr/doc/00042/15305/ | Partager |
Developpement de la peche de grands pelagiques dans les antilles francaises et organisation du marche des produits de la mer Auteur(s) : Lantz, Frederic Résumé : The development of large pelagic fishing in the French Antilles is an integral part of a difficult economic situation of the fishing sector in Martinique where this development can seem like a solution to increasingly acute problems. Indeed, for the regulatory authorities as well as for many participants in the sector, it is imperative to find solutions to the lack of profitability of a part of the fishing ships and to confront the regular increase of the share of imports in supplying Martinique with seafood. This question about the possibilities of developing large pelagic fishing is not new since it is already mentioned in the Notice from the Economic and Social Committee of the Martinique Region in 1982. We will not show in this document a detailed analysis of small-scale fishing in Martinique. Since the latter has been abundantly studied by the team of the Caribbean Oceanological and Halieutic Research Centre (PROHC) between 1985 and 1987, we will take up these principal conclusions (with which we are in full agreement) and bring them up to date based on data collected during our mission from 11 to 24 April 1988. The first section devoted to the supply structure (local fishing and imports) will attempt to define under what conditions large pelagic fishing can be developed. The second section will address marketing and demand. Indeed, at the same time as the problems of developing large pelagic fishing, we are faced with the question of the organisation of seafood markets. This organisation is a fundamental issue for the small-scale fishing sector in the French Antilles since its long-term future depends upon it by setting different prices and amounts exchanged according to the structure it is given. We will come to a conclusion on the economic conditions of developing a large pelagic fishery and organising a market, this based on research and study work already done. We will indicate which investigations must be conducted to complete the set of factors for decision support in this area. To perform this assessment, we reconstructed from the long series 1970-1986 (sometimes with significant inadequacies): these are presented as an appendix. (OCR non controlé) Le développement de la pêche de grands pélagiques dans les Antilles Françaises s'inscrit dans un contexte économique difficile du secteur de la pêche en Martinique où ce développement peut apparaître comme une solution à des problèmes de plus en plus aigus. En effet, pour les autorités de tutelle ainsi que pour de nombreux intervenants dans le secteur, il est impératif de trouver des solutions au manque de rentabilité d'une partie des unités de pêche et de faire face à l'augmentation régulière de la part des importations dans l'approvisionnement de la Martinique en produits de la mer. Cette question sur les possibilités d'un développement de la pêche de grands pélagiques n'est pas nouvelle puisqu'elle est déjà évoquée dans l'Avis du Comité Economique et Social de la Région Martinique en 1982. On ne présentera pas dans ce document une analyse détaillée de la pêche artisanale en Martinique. Celle-ci ayant été abondamment étudiée par l'équipe du Pôle de Recherche Océanologique et Halieutique Caraïbe (PROHC) entre 1985 et 1987, on reprendra ces principales conclusions (avec lesquelles nous sommes en plein accord) en les actualisant à partir des informations recueillies lors de notre mission du 11 au 24 avril 1988. La première section consacrée à la structure d'offre (pêche locale et importations) s'attachera à définir dans quelles conditions peut être développée une pêche de grands pélagiques. Là seconde section traitera de la commercialisation et de la demande. En effet parallèlement aux problèmes de développement d'une pêche de grands pélagiques, se pose la question de l'organisation du marché des produits de la mer. Cette organisation est un enjeu primordial pour le secteur de la pêche artisanale dans les Antilles Françaises puisqu'elle conditionne son avenir à long terme en définissant des prix et des quantités échangées différents suivant la structure qu'on lui donne. On conclura sur les conditions économiques du développement d'une pêche de grands pélagiques et de l'organisation d'un marché, ceci à partir des travaux de recherche et des études déjà réalisés. On indiquera quelles investigations doivent être menées pour compléter l'ensemble des éléments d'aide à la décision dans ce domaine. Pour effectuer cette évaluation, on a reconstituer des séries longues 1970-1986 (parfois avec des carences importantes) : celles-ci sont présentées en annexe. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/1988/rapport-2519.pdf http://archimer.ifremer.fr/doc/00000/2519/ | Partager |
Fish, fishers, seals and tourists: Economic consequences of creating a marine reserve in a multi-species, multi-activity context Auteur(s) : Boncoeur, Jean Alban, Frederique Guyader, Olivier Thebaud, Olivier Éditeur(s) : Wiley Résumé : This paper investigates some economic consequences of creating a marine reserve on both fishing and ecotourism, when the range of controllability of fishing effort is limited and the impact of the reserve on ecosystem is considered. The issue is illustrated by the example of creating a no-take zone in part of a region where fishing is managed through a limited entry license system, and which is inhabited by two interacting stocks: a stock of prey (fish) and a stock of predators (seals). While the former is targeted by commercial fishing, the latter is not subject to harvest but is a potential basis for a commercial non-extractive activity (seal watching). Analysis is conducted with the help of a bioeconomic model combining the features of marine reserve modeling and of multispecies modeling. Following a description of the model, results of several simulation runs are presented. These show that creating a marine reserve has more complex economic implications than predicted in studies focused exclusively on one stock and/or commercial fisheries. More specifically, the model shows that the dynamics of the two interacting stocks reduces the benefits of the no-take zone for the fishing industry, while it makes the creation of this zone provide an opportunity for the development of ecotourism. Due to this dynamics, the model suggests that the optimal size of the reserve is larger when ecotourism is taken into account along with fishing activities. Natural Resource Modeling (1939-7445) (Wiley), 2002-12 , Vol. 15 , N. 4 , P. 387–411 Droits : 2002 Rocky Mountain Mathematics Consortium http://archimer.ifremer.fr/doc/00244/35506/34010.pdf DOI:10.1111/j.1939-7445.2002.tb00095.x http://archimer.ifremer.fr/doc/00244/35506/ | Partager |
Complexities and Uncertainties in Transitioning Small-Scale Coral Reef Fisheries Auteur(s) : Leenhardt, Pierre Lauer, Matthew Madi Moussa, Rakamaly , Holbrook, S. J. Rassweiler, Andrew Schmitt, Russell J. Claudet, Joachim Auteurs secondaires : Laboratoire d'Excellence CORAIL (LabEX CORAIL) ; Institut de Recherche pour le Développement (IRD) - Université des Antilles et de la Guyane (UAG) - École des hautes études en sciences sociales (EHESS) - École pratique des hautes études (EPHE) - Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) - Université de la Réunion (UR) - Université de la Polynésie Française (UPF) - Université de Nouvelle Calédonie - Institut d'écologie et environnement Centre de recherches insulaires et observatoire de l'environnement (CRIOBE) ; Université de Perpignan Via Domitia (UPVD) - École pratique des hautes études (EPHE) - Centre National de la Recherche Scientifique (CNRS) Department of Anthropology [San Diego] ; University of California [San Diego] (UC San Diego) Department of Ecology, Evolution and Marine Biology ; University of California [Santa Barbara] Coastal Research Center, Marine Science Institute ; University of California [Santa Barbara] Department of Biological Science [Tallahassee] ; Florida State University [Tallahassee] (FSU) Éditeur(s) : HAL CCSD Frontiers Media Résumé : International audience Coral reef fisheries support the development of local and national economies and are the basis of important cultural practices and worldviews. Transitioning economies, human development, and environmental stress can harm this livelihood. Here we focus on a transitioning social-ecological system as a case study (Moorea, French Polynesia). We review fishing practices and three decades of effort and landing estimates with the broader goal of informing management. Fishery activities in Moorea are quite challenging to quantify because of the diversity of gears used, the lack of centralized access points or markets, the high participation rates of the population in the fishery, and the overlapping cultural and economic motivations to catch fish. Compounding this challenging diversity, we lack a basic understanding of the complex interplay between the cultural, subsistence, and commercial use of Moorea's reefs. In Moorea, we found an order of magnitude gap between estimates of fishery yield produced by catch monitoring methods (2 t km −2 ∼ year −1) and estimates produced using consumption or participatory socioeconomic consumer surveys (∼24 t km −2 year −1). Several lines of evidence suggest reef resources may be overexploited and stakeholders have a diversity of opinions as to whether trends in the stocks are a cause for concern. The reefs, however, remain ecologically resilient. The relative health of the reef is striking given the socioeconomic context. Moorea has a relatively high population density, a modern economic system linked into global flows of trade and travel, and the fishery has little remaining traditional or customary management. Other islands in the Pacific in similar contexts in Polynesia such as Hawaii, that continue to develop economically, may have small-scale fisheries that increasingly resemble Moorea. Therefore, understanding Moorea's reef fisheries may provide insight into their future. ISSN: 2296-7745 Droits : http://creativecommons.org/licenses/by/ hal-01325804 https://hal-univ-perp.archives-ouvertes.fr/hal-01325804 https://hal-univ-perp.archives-ouvertes.fr/hal-01325804/document https://hal-univ-perp.archives-ouvertes.fr/hal-01325804/file/fmars-03-00070.pdf DOI : 10.3389/fmars.2016.00070 | Partager |
Drifting FADs used in tuna fisheries: an ecological trap? Auteur(s) : Marsac, F Fonteneau, Alain Menard, Frederic Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999 Résumé : This paper discusses the hypothesis that small tunas and the various species found in association with drifting fads (such as "mahi-mahi", rainbow runner, wahoo, etc.) may be biologically trapped by such a strong association. Massive seeding of drifting artificial fads was observed worldwide during recent years. In this hypothesis, we suggest that fads may alter some biological characteristics of epipelagic populations associated with them: migration, growth, condition factors, predation and natural mortality. As fads are most often used in the equatorial currents, they tend to exhibit zonal drift. Therefore, the associated populations would be artificially transferred from one part of the ocean to another, when they would show different movement patterns in the absence of fads. Natural logs were probably beneficial in terms of ecology and evolution, because they tend to accumulate in convergence areas, most often considered as rich forage areas. Now, fads are seeded in offshore areas, which are not necessarily favourable for tuna feeding. This apparently strong association between fishes and drifting fads may then produce an unexpected biological impact on tuna populations and their associated fauna. The plan is to test this hypothesis in the Atlantic, developing an ad hoc research programme based on tagging, biological and physiological studies, in association to an analysis of high resolution fishery data before and after the development of the fad fishery.Original Abstract: Cet article discute l'hypothese selon laquelle les petits thons et les differentes especes associees a des DCP derivants (comme les coryphenes, elagatis, thazards, etc.) pourraient etre pris dans un piege biologique resultant de cette forte association. Le deploiement massif de DCP artificiels derivants a ete constate a l'echelle mondiale au cours des dernieres annees. Dans cette hypothese, ces DCP, colonises en permanence par de grandes fractions de populations epipelagiques, pourraient modifier les caracteristiques biologiques des especes concernees: leur migration, leur croissance, leurs facteurs de condition, la predation et la mortalite naturelle. Les DCP etant plus frequemment utilises dans les courants equatoriaux, ils tendent a deriver zonalement. Ainsi, les populations associees seraient artificiellement transferees d'un bord a l'autre de l'ocean, alors qu'elles manifesteraient d'autres types de deplacements en l'absence de DCP. Les debris naturels etaient probablement benefiques sur le plan de l'ecologie et de l'evolution car ils s'accumulent dans des zones de convergence le plus souvent considerees comme des zones riches en nourriture. Maintenant, les DCP sont mouilles au large, dans des zones qui peuvent ou non etre favorables a l'alimentation des thons. Cette association apparemment forte entre poissons et DCP derivants pourrait alors causer un impact biologique inattendu sur les populations pelagiques (thons et faune accompagnante). L'objectif est de tester cette hypothese dans l'Atlantique au moyen d'un programme de recherche s'appuyant sur du marquage et des etudes biologiques et physiologiques, parallelement a une analyse des donnees de peche (tailles et CPUE, avant et apres le deploiement des DCP derivants). Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/00042/15303/12636.pdf http://archimer.ifremer.fr/doc/00042/15303/ | Partager |
Unravelling the ontogeny of a Devonian early gnathostome, the “acanthodian” Triazeugacanthus affinis (eastern Canada) Auteur(s) : Chevrinais, Marion Sire, Jean-Yves Cloutier, Richard Auteurs secondaires : Université du Québec A Rimouski (UQAR) Evolution et développement du squelette (EDS) ; Evolution Paris Seine ; Université Nice Sophia Antipolis (UNS) ; Université Côte d'Azur (UCA) - Université Côte d'Azur (UCA) - Centre National de la Recherche Scientifique (CNRS) - Université des Antilles et de la Guyane (UAG) - Université Pierre et Marie Curie - Paris 6 (UPMC) - Université Nice Sophia Antipolis (UNS) ; Université Côte d'Azur (UCA) - Université Côte d'Azur (UCA) - Centre National de la Recherche Scientifique (CNRS) - Université des Antilles et de la Guyane (UAG) - Université Pierre et Marie Curie - Paris 6 (UPMC) - Systématique, adaptation, évolution (SAE) ; Université Pierre et Marie Curie - Paris 6 (UPMC) - Centre National de la Recherche Scientifique (CNRS) Éditeur(s) : HAL CCSD PeerJ Résumé : International audience The study of vertebrate ontogenies has the potential to inform us of shared developmental patterns and processes among organisms. However, fossilised ontogenies of early vertebrates are extremely rare during the Palaeozoic Era. A growth series of the Late Devonian ''acanthodian'' Triazeugacanthus affinis, from the Miguasha Fossil-Fish Lagerstätte, is identified as one of the best known early vertebrate fossilised ontogenies given the exceptional preservation, the large size range, and the abundance of specimens. Morphological, morphometric, histological and chemical data are gathered on a growth series of Triazeugacanthus ranging from 4 to 52 mm in total length. The developmental trajectory of this Devonian ''acanthodian'' is characteristic of fishes showing a direct development with alternating steps and thresholds. Larvae show no squamation but a progressive appearance of cartilaginous neurocranial and vertebral elements, and appendicular elements, whereas juveniles progress in terms of ossification and squamation. The presence of cartilaginous and bony tissues, discriminated on histological and chemical signatures, shows a progressive mineralisation of neurocranial and vertebral elements. Comparison among different body proportions for larvae, juveniles and adults suggest allometric growth in juveniles. Because of the phylogenetic position of ''acanthodians'', Triazeugacanthus ontogeny informs us about deep time developmental conditions in gnathostomes. ISSN: 2167-8359 Droits : http://creativecommons.org/licenses/by/ hal-01633978 http://hal.upmc.fr/hal-01633978 http://hal.upmc.fr/hal-01633978/document http://hal.upmc.fr/hal-01633978/file/peerj-3969.pdf DOI : 10.7717/peerj.3969 | Partager |
Évaluation, scénarios et viabilité écologique et économique des pêcheries côtières tropicales : application au cas de la Guyane française ; Evaluation and ecological-economic scenarios of tropical coastal fisheries : the case of the french guiana Auteur(s) : Cissé, Abdoul Ahad Auteurs secondaires : Antilles-Guyane Célimène, Fred Résumé : La nécessité d'une approche intégrée des pêches est actuellement largement affirmée, notamment par la FAO, en particulier dans le contexte des pêcheries artisanales tropicales. Ces pêcheries à petites échelles, souvent multi-spécifiques sont très importantes en termes d'emploi et de production, y compris pour la sécurité alimentaire. Néanmoins ces pêcheries et la biodiversité exploitées sont souvent marquées, d'une part, par le manque de données rendant difficile leur gestion dans le cadre d'une approche écosystémique, d'autre part, par la complexité des systèmes écologiques et économiques sous-jacents incluant interactions trophiques et techniques.Cette thèse contribue à la mise au point d'outils bioéconomiques adaptés aux petites pêcheries tropicales dans la perspective d'une gestion durable des pêches fondée sur l'approche écosystémique. Dans cette perspective, la pêcherie côtière en Guyane Française constitue un cas d'étude particulièrement fécond. La thèse propose ainsi des évaluations multi-critères, des modèles bioéconomiques complexes et des scénarios de gestion viable pour cette pêcherie.Dans un premier temps l'analyse statistique multi-variée suggère un statut global satisfaisant de la pêcherie en termes de durabilité. Cependant des différences de performance sont notées au sein de la pêcherie, notamment au niveau des zones frontalières. Aussi des améliorations dans le mode de gestion sont proposées. Ensuite, à travers la modélisation bioéconomique, les projections des différents scénarios de pêche montrent qu'à long terme le niveau d'exploitation actuel peut ne pas être en adéquation avec la future augmentation de la demande locale et qu'une perte de biodiversité peut avoir lieu. Un scénario dit de « co-viabilité » conciliant des objectifs à la fois écologique, économique et social, avec une probabilité de réalisation satisfaisante, est mis en exergue. Enfin, la comparaison des comportements optimaux en situation coopératif et non coopératif, montre dans quelle mesure la viabilité est favorisée quand les acteurs coopèrent. Au-delà du diagnostic apporté pour le cas d'étude, la méthode utilisée s'avère prometteuse dans le contexte des petites pêcheries tropicales, tandis que l'approche de « co-viabilité » permet de trouver les modalités d'exploitation dans le cadre de compromis entre durabilité écologique et socio-économique, ce que les principes de gestion halieutiques traditionnels ne permettent généralement pas. The need for an integrated approach to fisheries is now widely affirmed, including the FAO, in particular in the context of tropical artisanal fisheries. These small-scale fisheries, often multispecies are very important in terms of production, employment and food security. However these fisheries and the exploited resources are often characterized by a lack of data making difficult their management within an ecosystem approach, and by the ecological and economic system complexities including trophic and technological interactions.This thesis aims to contribute to the development of bioeconomic tools for small tropical fisheries in a sustainable management perspective based on the ecosystem approach. In this perspective, the French Guiana coastal fishery constitutes an interesting case study. The thesis proposes multi-criteria evaluations, complex bioeconomic models and viable management scenarios for this fishery. At first, multivariate statistical analysis suggests a satisfactory overall status of the fishery in terms of sustainability. However, some performance differences are noted within the fishery, particularly at border areas. Also, management improvements are proposed. Then, through bioeconomic modeling, projections of different fishing scenarios show that, in the long term, the current exploitation level may not be consistent with the future increase of local demand and a loss of biodiversity may occur. A scenario called "co-viability" reconciling ecological, economic and social objectives, with a high probability of achievement is exhibited. Finally, the comparison of optimal behavior in cooperative and non-cooperative conditions, confirms that harvest levels are greater when actors do not cooperate. Furthermore, it is shown that the state of the ecosystem depends on the fishing strategies and the type of interaction between species. Beyond the diagnosis made for the case study, the method is promising in the context of small tropical fisheries, while the co-viability approach allows finding the exploitation conditions under which ecological and socio-economic sustainability are meet, what the conventional fisheries management generally do not allow. http://www.theses.fr/2013AGUY0620/document | Partager |
Le Dispositif de Concentration de Poissons (DCP): une alternative à la forte pression de pêche sur les ressources récifales de la Martinique Auteur(s) : Taquet, Marc Éditeur(s) : University of Miami Résumé : This paper describes the fishing activity in Martinique, French West Indies. It draws up the balance sheet of acquirements about marine resources of the island. The difficulties of fisheries management are discussed with reference to biologists and economists works in the last ten years. We also show how management efforts to decrease fishing pressure on reef resources has induced the implantation of a new technology: the Fish Aggregating Deviee. The differing histories of development of FADs in the French West Indies are compared. The positive results from the introduction of the FADs and the estimated risks due to the transferance of fishing pressure on the continental shelf is presented. The use of FADs to enhance the exploitation of marine resources is a concept that justifies.a cooperative plan throughout the Caribbean region A partir d'une présentation synthétique de l'activité de pêche en Martinique, cette note dresse le bilan des connaissances actuelles sur l'état des ressources halieutiques de l'île. Les difficultés de la gestion des pêches sont discutées en référence aux travaux réalisés par les halieutes et les économistes des pêches au cours des dix dernières années. On montre comment un objectif de gestion, l'allégement de la pression de pêche sur les ressources démersales, a pu conduire à l'implantation d'une nouvelle technologie: le dispositif de concentration de poissons. Les différents contextes de développement des DCP observés dans les deux départements français des Antilles sont comparés. Les retombées positives de l'introduction des dispositifs sont évaluées mais le risque d'aboutir à un report d'une partie de la puissance de pêche sur le plateau est également évoqué. L'influence du DCP sur l'exploitation des ressources halieutiques constitue un argument supplémentaire pour intensifier la coopération caribéenne sur ce thème Proceedings - Gulf and Caribbean Fisheries Institute, University of Miami (0072-9019) (University of Miami), 1998 , Vol. 50 , P. 249-261 Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/00113/22409/20106.pdf http://archimer.ifremer.fr/doc/00113/22409/ | Partager |
An overview of the FADs fishery in the Mediterranean Sea Auteur(s) : Morales-nin, B Cannizzaro, L Massuti, E Potoschi, A Andaloro, F Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999 15-19 octobre 1999 Résumé : The Mediterranean small-scale fleet is highly adaptive, showing a dynamic fishing intensity and strategy, and exploiting seasonal abundant resources. In this area, the aggregatory behaviour under floats of juvenile fish has been used since ancient times to exploit oceanic migratory species such as dolphinfish (Coryphaena hippurus), using Fish Aggregating anchored Devices (fads). A total of 2 300 boats are engaged in this fishery from August to December, the main fishing areas being those around Malta, Tunisia, Sicily and Majorca. The fads ( arrow right m2) are made of different cheap floating materials, and are moored in fixed places, ranging from shore waters to areas 60 miles off the coast (1 500 m depth). Each boat deploys an average of 20 to 100 fads. The gears used are special surrounding nets without purse line, and traditional purse seine nets. The fishery exploits young-of-the-year dolphinfish (<6 months old), originated by a pre-spawning migration of adults from Atlantic waters. Their catches show high annual and monthly variability, depending on the recruitment and the accessibility of recruits to the fishery. Pilotfish (Naucrates ductor) and greater amberjack (Seriola dumerili) are also exploited in this fishery as by-catch. A total of about 1 000 metric tons of dolphinfish are yearly caught mainly in September-October. The fads are historically laid in August. Recently, the fads fishing period has increased in Sicily, and the fads are laid in July, so as to catch pilotfish and greater amberjak juveniles. In recent years, the interest for this fishing method and the study of these fisheries has increased in the Mediterranean. Though the market and its seasonality limit this exploitation, this fishery is economically profitable with good revenue. Droits : Ifremer http://archimer.ifremer.fr/doc/00042/15286/12672.pdf http://archimer.ifremer.fr/doc/00042/15286/ | Partager |
Is total serum protein a good indicator for welfare in reared sea bass (Dicentrarchus labrax)? Auteur(s) : Coeurdacier, Jean-luc Dutto, Gilbert Gasset, Eric Blancheton, Jean-paul Éditeur(s) : Edp Sciences S A Résumé : Reared sea bass were submitted to six stressful situations: hyperoxia with or without hypercapnia, increased stocking density in an open flow or recirculating system, transfer to another tank and nodavirus injection. The potentially negative impact of these factors on the lives of sea bass was investigated by measuring 9 water parameters and 19 fish parameters including total serum protein (TSP). TSP has already been used to evaluate stress. The present study investigates data of previous and new experiments, concentrating on the potential use of TSP as a routine indicator to assess welfare in sea bass reared on fish farms. In the current experiment, oxygen and carbon dioxide were seen to affect levels of TSP, but alterations were too erratic to enable proper comparison, probably because they are normal components of the fish environment and become toxic only by dose increase. TSP decreased when stocking density increased. After transfer to another tank, TSP decreased to 14% for three weeks and then increased during the fourth week through compensative overproduction, before returning to normal levels after 2 months. The results confirmed that transfer is an important stress factor for fish, with cumulative effects for successive transfers. TSP alteration of nodavirus-injected fish depends on the type of symptoms, which can be divided into 3 groups: (i) dying fish, in which TSP increased sharply due to over-production of protein involved in non-specific defences and inflammation, then decreased dramatically before death; (ii) whirling fish, a group that included both fish that later died, in which TSP decreased, and fish that subsequently survived, in which TSP increased due to development of specific immunity; and (iii) asymptomatic fish, in which TPS was similar to control levels and which were probably insensitive to nodavirus and/or had developed defences. In this paper, different mechanisms of TSP alteration are proposed and the interest of TSP as a field parameter is discussed. TSP is a non-destructive parameter that is robust, easy to measure everywhere and cheap, representing a suitable way of monitoring the overall welfare of fish by its regular increase. It can be used only as a "warning" of poor rearing conditions, however, and further investigations would be needed to identify the specific stress or health disorder. Aquatic Living Resources (0990-7440) (Edp Sciences S A), 2011-04 , Vol. 24 , N. 2 , P. 121-127 Droits : EDP Sciences, IFREMER, IRD 2011 http://archimer.ifremer.fr/doc/00043/15382/12740.pdf DOI:10.1051/alr/2011130 http://archimer.ifremer.fr/doc/00043/15382/ | Partager |
Marine cage fish farming Auteur(s) : Espeut, P. Harache, Yves Lemarie, Gilles Ricard, Jean-marc 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/ | Partager |
Fishing strategies, economic performance and management of moored fishing aggregating devices in Guadeloupe Auteur(s) : Guyader, Olivier Bellanger, Manuel Reynal, Lionel Demaneche, Sebastien Berthou, Patrick Éditeur(s) : Edp Sciences S A Résumé : Moored FADs (MFADs) have been a key area for development in Guadeloupe (Lesser Antilles) since the late 1980's. The main objectives underpinning the development of MFADs were to (i) reduce fishing pressure on coastal fishing resources; (ii) boost fishermen's incomes; and (iii) increase local consumption of locally generated fishery products as a proportion of overall consumption. This paper gives an overview of the current structure of Guadeloupe's fishing fleet and fisheries, with a specific focus on MFAD fleets in a relatively unstructured environment with regard to regulation, and so how these fleets operate in a context of unrestricted development of private MFADs. In addressing the following key issues, this paper aims to: assess the economic performance of fleets operating on MFADs, understand why the MFAD fishing activity has not developed more than it has, and suggest how better MFAD management could improve the situation. Socio-economic information on a trip and fleet level basis were collected and stored on a fisheries information system to analyse the relative attractiveness of MFAD fishing and assess the overall economic performance of MFAD fleets as compared to other non-MFAD fleets. Non-monetary variables were also tested to explain the degree of dependence on MFADs. In 2008, economic returns from FADs were relatively low, both in terms of wages for the crews and in terms of profit for vessel owners. Earnings were higher than coastal fishing activities, but seem to have been very sensitive to the indicators used in our analysis. MFADs are expected to become much more attractive as a result of MFAD regulation, especially through the establishment of collective MFADs. Aquatic Living Resources (0990-7440) (Edp Sciences S A), 2013-01 , Vol. 26 , N. 1 , P. 97-105 Droits : EDP Sciences, IFREMER, IRD 2013 http://archimer.ifremer.fr/doc/00137/24836/22914.pdf DOI:10.1051/alr/20013044 http://archimer.ifremer.fr/doc/00137/24836/ | Partager |
Acoustic indices provide information on the status of coral reefs: an example from Moorea Island in the South Pacific Auteur(s) : Bertucci, Frédéric Parmentier, Eric Lecellier, Gaël Hawkins, Anthony, Lecchini, David Auteurs secondaires : Laboratoire de Morphologie Fonctionnelle et Evolutive ; Université de Liège Centre de recherches insulaires et observatoire de l'environnement (CRIOBE) ; Université de Perpignan Via Domitia (UPVD) - École pratique des hautes études (EPHE) - Centre National de la Recherche Scientifique (CNRS) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) Université Paris-Saclay Laboratoire d'Excellence CORAIL (LabEX CORAIL) ; Institut de Recherche pour le Développement (IRD) - Université des Antilles et de la Guyane (UAG) - École des hautes études en sciences sociales (EHESS) - École pratique des hautes études (EPHE) - Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) - Université de la Réunion (UR) - Université de la Polynésie Française (UPF) - Université de Nouvelle Calédonie - Institut d'écologie et environnement Loughine Marine Research ; Environmental Research Institute (ERI) Total Foundation Éditeur(s) : HAL CCSD Nature Publishing Group Résumé : International audience Different marine habitats are characterised by different soundscapes. How or which differences may be representative of the habitat characteristics and/or community structure remains however to be explored. A growing project in passive acoustics is to find a way to use soundscapes to have information on the habitat and on its changes. In this study we have successfully tested the potential of two acoustic indices, i.e. the average sound pressure level and the acoustic complexity index based on the frequency spectrum. Inside and outside marine protected areas of Moorea Island (French Polynesia), sound pressure level was positively correlated with the characteristics of the substratum and acoustic complexity was positively correlated with fish diversity. It clearly shows soundscape can be used to evaluate the acoustic features of marine protected areas, which presented a significantly higher ambient sound pressure level and were more acoustically complex than non-protected areas. This study further emphasizes the importance of acoustics as a tool in the monitoring of marine environments and in the elaboration and management of future conservation plans. Coral reef ecosystems are among the most biologically diverse and complex marine ecosystems worldwide. In addition to their biological and ecological importance, coral reefs support major economic and physical functions (e.g. food production, tourism, biotechnology development and coastal protection) that are essential for many countries 1. Unfortunately, coral reefs are severely threatened: 20% of coral reefs can no longer be defined as such, another 25% are currently endangered and another 25% will be endangered by 2050 2. The frequency and severity of natural perturbations (e.g. cyclone, outbreaks of predators, particularly the crown-of-thorns starfish [COTS] Acanthaster planci) and anthropogenic perturbations (e.g. ocean acidification, pesticides, rising seawater temperatures) on coral reefs have greatly increased worldwide in the last three decades, and, as a consequence, reef communities (fish, coral and benthic invertebrates) have suffered unprecedented levels of decline 3,4 ISSN: 2045-2322 hal-01370610 https://hal-uvsq.archives-ouvertes.fr/hal-01370610 https://hal-uvsq.archives-ouvertes.fr/hal-01370610/document https://hal-uvsq.archives-ouvertes.fr/hal-01370610/file/2016%20Sci.Rep.pdf DOI : 10.1038/srep33326 | Partager |
Les cantonnements de pêche à la Martinique : bilan et perspectives Auteur(s) : Valdivia, Florence Éditeur(s) : Université des Antilles Études caribéennes Résumé : Le cantonnement de pêche est un outil administratif et juridique français employé pour la gestion de la ressource halieutique et la réglementation de la pêche sur un site marin défini. Cet outil a été mis en place à la Martinique (Petites Antilles) en 1999, à la demande des marins-pêcheurs confrontés à la raréfaction des stocks de poissons au sein de la bande côtière. Les autorités compétentes sur le milieu marin ont installé ce dispositif sur huit zones réparties autour de l’île (de la côte Atlantique à la côte Caraïbes). Le cantonnement de pêche reste peu documenté scientifiquement à ce jour, en dehors d’inventaires ichtyologiques réalisés par des scientifiques-biologistes. Il est donc opportun de retracer les étapes de la mise en place de cet outil et d’analyser les premiers résultats et les enjeux. Cantonment fishing is a French legal and administrative tool used to manage fisheries resources and the regulation of fishing on marine site defined. This tool was developed in Martinique (Lesser Antilles) in 1999, at the request of fishermen facing depletion of fish stocks in the coastal strip. The competent authorities on the marine environment have installed this device on eight areas spread around the island (the Atlantic coast to the Caribbean coast). Cantonment fishing is little scientifically documented to date, apart from fishery surveys conducted by scientists-biologists. It is therefore appropriate to retrace the steps of the development of this tool and analyze the first results and challenges. Martinique Droits : info:eu-repo/semantics/openAccess urn:doi:10.4000/etudescaribeennes.6800 http://journals.openedition.org/etudescaribeennes/6800 | Partager |
Evolution technologique des DCP en Polynesie francaise Auteur(s) : Leproux, E Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999 Résumé : French Polynesia started it's Fish Aggregating Device programme in June 1981 with the positioning of the first buoy offshore of the main island of Tahiti. Since then, 251 structures have been installed throughout the 5 archipelagoes of this French overseas territory. The shape and size of the devices have evolved 8 times over this period, however, a single model has not yet been adopted. Trials are currently underway using lighter structures similar to those found in the Indian Ocean. The anchoring lines have progressively been modified through better knowledge of material and product availability, as well as better understanding of environmental constraints. The programme is entirely financed by the territorial government and managed by the public sector. This ongoing technical assistance, aimed towards the local small-scale coastal fishery, is considered an important factor to maintaining this activity alive. Up until 1997, this economical support policy of outer island populations far from the metropolis central town, along with incidental fishing methods around FADs, have given mitigated results without nevertheless putting into cause this programme. The use of 'drifting handlines' retained at the surface by small indicator floats are one of the contributing factors to the degradation of the anchor lines. It is now commonly accepted that a new fishing strategy must be adopted so that professional coastal fishermen become more aware with regards to an expensive work tool due to local bathymetric conditions, so that fishing effort is increased through the development of better adapted fishing techniques, and finally so that community spirit rules over individualism.Original Abstract: Le programme d'ancrage de DCP en Polynesie francaise a vu le jour en juin 1981 avec l'implantation d'un premier dispositif au large des cotes de Tahiti. Depuis cette date, ce sont 251 structures qui ont ete installees dans les cinq archipels de ce pays d'outre-mer. La forme et la taille des bouees ont evolue huit fois sans etre definitivement arretees a un seul modele et des essais sur des structures legeres de type " Ocean Indien " sont en cours. Les lignes d'ancrage ont fait l'objet de modifications progressives en raison de meilleures connaissances des produits ainsi que des contraintes du milieu environnant. Ce programme est finance en totalite par le territoire de la Polynesie francaise et gere par le secteur public. Il s'adresse a la pecherie artisanale et cotiere qui considere depuis de nombreuses annees cette assistance technique comme un atout indispensable au maintien de son activite. La politique d'engagement de ce soutien economique jusqu'en 1997 aupres des populations d'iles et atolls tres eloignes de la capitale ainsi que l'incidence de la technique de peche la plus repandue autour des DCP ont abouti a des resultats mitiges sans pour autant remettre en cause ce programme. En effet, les lignes a main derivantes et retenues en surface par une petite bouee temoin sont un des principaux facteurs de degradation des lignes d'ancrage. Il est desormais reconnu par tous les intervenants qu'une nouvelle strategie doit etre deployee afin que les pecheurs cotiers professionnels soient mieux responsabilises face a un outil de travail onereux en raison de la bathymetrie environnante, pour que l'effort de peche soit accru par l'utilisation de techniques de peche mieux adaptees, et enfin que l'esprit communautaire prime sur l'individualisme. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/00042/15292/12649.pdf http://archimer.ifremer.fr/doc/00042/15292/ | Partager |
Aromatase, estrogen receptors and brain development in fish and amphibians Auteur(s) : Coumailleau, Pascal Pellegrini, Elisabeth Adrio, Fátima Diotel, Nicolas Cano-Nicolau, Joel Nasri, Ahmed Vaillant, Colette Kah, Olivier Auteurs secondaires : Institut de recherche, santé, environnement et travail [Rennes] (Irset) ; Université d'Angers (UA) - Université des Antilles et de la Guyane (UAG) - Université de Rennes 1 (UR1) - École des Hautes Études en Santé Publique [EHESP] (EHESP) - Institut National de la Santé et de la Recherche Médicale (INSERM) - Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ) Department of Cell Biology and Ecology ; university of Santigo de Compostela Groupe d'Etude sur l'Inflammation Chronique et l'Obésité (GEICO) ; Université de la Réunion (UR) Éditeur(s) : HAL CCSD Résumé : International audience Estrogens affect brain development of vertebrates, not only by impacting activity and morphology of existing circuits, but also by modulating embryonic and adult neurogenesis. The issue is complex as estrogens can not only originate from peripheral tissues, but also be locally produced within the brain itself due to local aromatization of androgens. In this respect, teleost fishes are quite unique because aromatase is expressed exclusively in radial glial cells, which represent pluripotent cells in the brain of all vertebrates. Expression of aromatase in the brain of fish is also strongly stimulated by estrogens and some androgens. This creates a very intriguing positive auto-regulatory loop leading to dramatic aromatase expression in sexually mature fish with elevated levels of circulating steroids. Looking at the effects of estrogens or anti-estrogens in the brain of adult zebrafish showed that estrogens inhibit rather than stimulate cell proliferation and newborn cell migration. The functional meaning of these observations is still unclear, but these data suggest that the brain of fish is experiencing constant remodeling under the influence of circulating steroids and brain-derived neurosteroids, possibly permitting a diversification of sexual strategies, notably hermaphroditism. Recent data in frogs indicate that aromatase expression is limited to neurons and do not concern radial glial cells. Thus, until now, there is no other example of vertebrates in which radial progenitors express aromatase. This raises the question of when and why these new features were gained and what are their adaptive benefits. This article is part of a Special Issue entitled: Nuclear receptors in animal development. Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms Droits : info:eu-repo/semantics/OpenAccess hal-01102449 https://hal.archives-ouvertes.fr/hal-01102449 https://hal.archives-ouvertes.fr/hal-01102449/document https://hal.archives-ouvertes.fr/hal-01102449/file/Coumailleau%20et%20al%20final%20manuscript.pdf DOI : 10.1016/j.bbagrm.2014.07.002 | Partager |
Données économiques maritimes françaises 1997 Auteur(s) : Kalaydjian, Regis Résumé : The purpose of this book is to value the economic significance of marine-related activities in France. Each industrial, or public non-commercial, sector is characterized by key figures relating to annual turnover, value added, employment and budget. These figures are accompanied with qualitative information on the recent development, current situation and future perspectives of the sector in terms of markets, employment and technological progress. Public and private R&D is also allowed for. Given the diversity of marine-related activities, this information aims at enabling the reader to assess their importance from a comparative angle.
From the sector-based approach it is possible to draw certain conclusions. Notably, commercial activities contributed over 1,3% of the GDP in 1995, such ratio having to be seen as a minimum estimate, worked out on the basis of available data. Seaside-related tourism is by far the most important industry. Most activities experienced a decrease in employment in the first half of the '90s. The estimated annual amount spent on R&D was over FFr 4,5 billion in the recent past period 1995-1996.
Le présent ouvrage a pour but d'évaluer l'importance économique des activités liées à la mer en France. Chaque secteur - industriel marchand, public non marchand - est caractérisé par des chiffres clés portant sur le chiffre d'affaires annuel, la valeur ajoutée, l'emploi, le budget. Ces indicateurs sont accompagnés d'informations qualitatives sur l'évolution récente, la situation actuelle et les perspectives du secteur : marchés, emplois, progrès technique. La R&D publique et privée est également prise en compte. Compte tenu de la diversité des activités liées à la mer, ces informations visent à permettre au lecteur d'en apprécier l'importance sous un angle comparatif. L'approche sectorielle permet de tirer certaines conclusions. Notamment, les activités marchandes ont contribué à plus de 1,3 % du PIB en 1995, un tel ratio devant être compris comme un minimum, calculé à partir des données disponibles. Le tourisme littoral est, de loin, l'activité la plus importante. Dans la plupart des branches, l'emploi baisse dans la première moitié des années 1990. Les dépenses annuelles de R&D sont estimées à plus de 4,5 milliards de francs dans la période récente 1995-1996. Droits : 1997 Ifremer http://archimer.ifremer.fr/doc/2001/rapport-1347.pdf http://archimer.ifremer.fr/doc/00000/1347/ | Partager |
La pêche au vivaneau en Guyane française Auteur(s) : Prevost, Etienne Résumé : Traditionally fished by line and conical fishing basket by Venezuelan ships, the red snapper resource off the coast of French Guyana (fish belonging to the Lutjanidae family) has been experiencing intensive fishing since 1984-85 due to the boom in classic fishing techniques and the development of trawl fishing.
The study evaluates the situation of this resource's potential: biology, sampling data, bio-statistics (size and sex), size-weight relationship of the three species, specific composition of the catches, describes fishing devices and prospecting, pinpoints fishing spots, gives a distribution of the Venezuelan and Martinique fishing effort.
Traditionnellement exploitée à la ligne à main et à la nasse par les navires vénézuéliens, la ressource en vivaneaux au large de la Guyane française (poissons appartenant à la famille des Lutjanidae) subit depuis 1984-85 une exploitation intense par l'accroissement des techniques de pêche classiques et le développement d'une pêcherie au chalut. L'étude fait le point sur les potentialités de cette ressource : biologie, données de l'échantillonnage, bio-statistique (taille et sexes), relation taille-poids des 3 espèces, composition spécifique des captures, décrit les engins de pêche et prospection, localise les lieux de pêche, donne une répartition de l'effort de pêche vénézuélien et chalutier martiniquais. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/1986/rapport-2646.pdf http://archimer.ifremer.fr/doc/00000/2646/ | Partager Voir aussi bow net trawl fishing line Franch Guyana Lutjanidae Guyane chalut nasse ligne engin de pêche Télécharger |
Accumulation and mobilization of lipids in relation to reproduction of yellowfin tuna (Thunnus albacares) in the Western Indian Ocean Auteur(s) : Zudaire, Iker Murua, Hilario Grande, Maitane Pernet, Fabrice Bodin, Nathalie Éditeur(s) : Elsevier Science Bv Résumé : Total lipid content and lipid class composition were analyzed in gonads, liver and white muscle of yellowfin tuna (Thunnus albacares) throughout ovary development to understand its reproductive allocation strategy and to assess the relation between female condition and reproduction. A total of 112 females were collected onboard purse-seiner in the Western Indian Ocean from January to March 2009, from June to July 2009, and from April to May 2010. Gonads were characterized by highly variable total lipid contents ranging from 5 to 27 μg mg−1 of wet weight (ww) with a predominance of neutral lipids, mainly triacylglycerols (TAG) and sterol- and wax-esters. The different lipid classes in gonads described an accumulative pattern through the maturity process from immature to hydration phase. Total lipid content in liver varied from 10 to 21 μg mg−1 ww, and serves as fuel for yellowfin tuna reproduction. TAG and phospholipid deposits became depleted as the ovary developed, suggesting a transfer of lipids directly from liver to the oocytes during vitellogenesis. In contrast, muscle total lipid content was low and constant throughout ovarian development (2.5–6 μg mg−1 ww). Hence, yellowfin tuna can be defined as an income-capital breeder species for which the cost of reproduction depends mainly on concurrent energy income from feeding and only little on stored lipids. Besides, no significant relationship between gonad lipid composition and fecundity was found in females able to spawn. Finally, the influence of yellowfin tuna aggregation behaviour on reproductive female condition has been investigated: gonad total lipid contents were higher in females caught in free-swimming schools than in females caught under fish aggregating devices (FADs). However, these results did not clarify whether the influence of FADs on associated yellowfin tuna affects their reproductive capacity. Fisheries Research (0165-7836) (Elsevier Science Bv), 2014-12 , Vol. 160 , P. 50-59 Droits : 2013 Elsevier B.V. All rights reserved. http://archimer.ifremer.fr/doc/00171/28266/28075.pdf DOI:10.1016/j.fishres.2013.12.010 http://archimer.ifremer.fr/doc/00171/28266/ | Partager Voir aussi Tropical tuna Lipid class composition Reproductive allocation strategy Income-capital breeder Fecundity FADs Télécharger |