Reproductive dynamics of swordfish (Xiphias gladius) in the southwestern Indian Ocean (Reunion Island). Part 1: oocyte development, sexual maturity and spawning Auteur(s) : Poisson, Francois Fauvel, Christian Éditeur(s) : EDP Sciences Résumé : The reproductive dynamics of swordfish (Xiphias gladius) was investigated from catches of the Reunion Island-based longline swordfish fishery between 19-25 degrees S and 48-54 degrees E. Thus, 1727 swordfish (size range 75-289 cm, lower jaw-to-fork length, LJFL) were sampled on board commercial fishing vessels during the period of May 1998 to January 2001. Reproductive activity was assessed using macroscopic gonad characteristics, trends of gonadal indexes for both sexes, oocyte size-frequency distributions and microscopic investigation of oocyte development stages. Size at first maturity (L-50) for female and male swordfish was estimated in Indian Ocean for the first time. L50 was estimated at 170 cm and 120 cm (LJFL) for females and males, respectively. Spawning occurred from October to April in the vicinity of Reunion Island where sex ratio of caught populations fluctuated seasonally. The seasonal changes in sex ratio and the incidence of larger individuals at the beginning of the spawning season provide some preliminary indications of synchronized movements of swordfish between spawning grounds and neighboring regions. Our results add significantly to knowledge about the reproductive biology of swordfish in the southwestern Indian Ocean. An overview of the available information on reproductive biology and dynamics of swordfish in Indian Ocean and eastern Pacific indicated that spawning activity is localized in discrete areas, and showed that there is incomplete information on spawning grounds in this extended area. La dynamique de la reproduction est étudiée chez des espadons (Xiphias gladius) capturés dans l'océan Indien, entre 1925 °Sud et 4854 °Est, par les palangriers de l'île de La Réunion. Ainsi, 1727 espadons de tailles comprises entre 75 et 289 cm (de l'extrémité de la mâchoire inférieure à la fourche caudale) ont été échantillonnés à bord de navires professionnels, de mai 1998 à janvier 2001. La reproduction est évaluée en analysant : les caractéristiques macroscopiques des gonades, l'évolution des indices gonadiques des deux sexes, les distributions de fréquence de taille des ovocytes et le développement des ovocytes au niveau microscopique. La taille à première maturité sexuelle (L50) des espadons de l'océan Indien est estimée pour la première fois ; elle atteint 170 cm pour les femelles et 120 cm pour les mâles. La saison de ponte s'étend d'octobre à avril aux abords de l'île tandis que le sexe-ratio fluctue de façon saisonnière. Les variations saisonnières du sexe-ratio et l'apparition de grands individus au début de la saison de ponte suggèrent des déplacements d'espadons entre cette zone de ponte et les régions voisines. Nos résultats apportent des informations fondamentales sur la biologie de la reproduction de l'espadon dans le sud-ouest de l'océan Indien. L'analyse de la bibliographie concernant biologie et la dynamique de la reproduction de l'espadon dans l'océan Indien et dans le Pacifique Est indique que l'activité de ponte est très localisée et que la connaissance des aires de pontes est encore incomplète dans cette région étendue. Aquatic Living Resources (0990-7440) (EDP Sciences), 2009 , Vol. 22 , N. 1 , P. 45-58 Droits : 2009 EDP Sciences http://archimer.ifremer.fr/doc/2009/publication-6353.pdf DOI:10.1051/alr/2009007 http://archimer.ifremer.fr/doc/00000/6353/ | Partager Voir aussi Indian Ocean Xiphias gladius Swordfish Seasonal distribution Size at first maturity Histology Spawning season Sex ratio Reproduction Télécharger |
Domestication of new species and sustainable development in fish culture Auteur(s) : Fontaine, Pascal Legendre, Marc Vandeputte, Marc Fostier, Alexis Éditeur(s) : John Libbey Eurotext ltd Résumé : How may fish domestication participate in sustainable development of aquaculture? The development of fish farming currently compensates for the stagnation of fishery catches while the market demand continues to increase. The development of fish farming relies on an active diversification of farmed fish species. A diversification based on the farming of native species could reduce the environmental impact of fish culture and could better fit to needs of local markets. Such development could also favour a more integrated local economy. In this context, the building of a generic approach for multi-species domestication is required to optimise the use of the technical and financial means available for fish culture diversification. Cahiers Agricultures (1166-7699) (John Libbey Eurotext ltd), 2009-04 , Vol. 18 , N. 2 , P. 119-124 Droits : 2009 John Libbey Eurotext ltd http://archimer.ifremer.fr/doc/2009/publication-6557.pdf DOI:10.1684/agr.2009.0293 http://archimer.ifremer.fr/doc/00000/6557/ | Partager |
The development of the purse seine fishery on drifting Fish Aggregating devices in the Eastern Pacific Ocean: 1992-1998 Auteur(s) : Lennert-cody, Ce Hall, Melanie Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999 15-19 octobre 1999 Résumé : Since the early 1990s, drifting Fish Aggregating Devices, or FADs, have rapidly become the dominant type of floating object used by the purse seine fishery in the Eastern Pacific Ocean to capture tunas. The development of this fishery for larger vessels is described using data collected by observers aboard vessels of more than 363 metric tons fish-carrying capacity. Bamboo rafts, equipped with radio-transmitters that allow for semi-continuous monitoring, are typically used as FADs. Old purse seine netting is often suspended below the bamboo raft to give the FAD an enhanced underwater profile. Similar to the fishery on flotsam between 1992-1998, most sets on FADs were made before 8 am, with skipjack and bigeye being the dominant tuna species caught, and yellowfin tuna captured in lesser amounts. Discard ratios of skipjack and bigeye were comparable for the two modes of fishing; however, the success rate on FADs for bigeye was more than twice that on non-FAD floating objects ("logs"). In addition, the fishery on logs was largely a coastal hshery, while the fishery on FADs extended west to 150 W, into areas that had not been significantly utilized by the purse seine fleet. The capture of tunas per set varied most with area, season and year. Nonetheless, capture per set for at least one of the three tuna species was also found to vary with the depth of the purse seine net and the amount of the netting hanging below the FAD. The effect of net depth and FAD depth on tuna capture varied by area, season and FAD color. Droits : Ifremer http://archimer.ifremer.fr/doc/00042/15282/12668.pdf http://archimer.ifremer.fr/doc/00042/15282/ | Partager Voir aussi Attracting techniques Seiners Seining Tuna fisheries Article Geographic Terms: ISE, Pacific Télécharger |
Tuna fishing and a review of payaos in the Philippines Auteur(s) : Dickson, J Natividad, Ac Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999 15-19 octobre 1999 Résumé : Payao is a traditional concept, which has been successfully commercialized to increase the landings of several species valuable to the country's export and local industries. It has become one of the most important developments in pelagic fishing that significantly contributed to increased tuna production and expansion of purse seine and other fishing gears. The introduction of the payao in tuna fishing in 1975 triggered the rapid development of the tuna and small pelagic fishery. With limited management schemes and strategies, however, unstable tuna and tuna-like species production was experienced in the 1980s and 1990s. In this paper, the evolution and development of the payao with emphasis on the technological aspect are reviewed. The present practices and techniques of payao in various parts of the country, including its structure, ownership, distribution, and fishing operations are discussed. Monitoring results of purse seine/ringnet operations including handline using payao in Celebes Sea and Western Luzon are presented to compare fishing styles and techniques, payao designs and species caught. The fishing gears in various regions of the country for harvesting payao are enumerated and discussed. The inshore and offshore payaos in terms of sea depth, location, designs, fishing methods and catch composition are also compared. Fishing companies and fisherfolk associations involved in payao operation are presented to determine extent of utilization and involvement in the municipal and commercial sectors of the fishing industry. The issues and problems concerning the use of payao, and its biological, economic impact as well as management aspect are presented. Recommendations are given for future research and actions. Droits : Ifremer http://archimer.ifremer.fr/doc/00042/15284/12670.pdf http://archimer.ifremer.fr/doc/00042/15284/ | Partager |
Ontogeny of the gastrointestinal tract of marine fish larvae Auteur(s) : Zambonino, Jose-luis Cahu, Chantal Éditeur(s) : Elsevier Résumé : Marine fish larvae undergo major morphological and cellular changes during the first month of life. The ontogeny of the gastrointestinal tract combines these two aspects of the larval development and is very interesting in that the timing of functional changes appears genetically hard-wired. The goal of this paper is to give an overview of the gastrointestinal development process in marine fish larvae, with particular attention to three species: sea bass; red drum; and sole, since the description of gut maturation in fish larvae was initiated during the last decade with these species. During the early stages, marine fish larvae exhibit particular digestive features. Concerning the exocrine pancreas, amylase expression decreases with age from the third week post-hatching in sea bass and red drum (approximately 400 degree days), whereas expression of other enzymes (trypsin, lipase, phospholipase A2...) increases until the end of the larva period. Moreover, secretory function of the exocrine pancreas progressively develops and becomes efficient after the third week of life. Concerning the intestine, enzymes of the enterocyte cytosol (in particular peptidase) have higher activity in young larvae than in older. Approximately in the fourth week of post-hatching development in sea bass, red drum and sole larvae, the cytosolic activities dramatically decline concurrently with a sharp increase in membranous enzyme activities of the brush border, such as alkaline phosphatase, aminopeptidase N, maltase... This process characterises the normal maturation of enterocytes in developing fish larvae and also in other vertebrates' species. The establishment of an efficient brush border membrane digestion represents the adult mode of digestion of enterocytes. This paper also describes the role of diet on the development of the gastrointestinal tract. Indeed, the maturational process of digestive enzyme can be enhanced, stopped, or delayed depending on the composition of the diet. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology (1532-0456) (Elsevier), 2001-12 , Vol. 130 , N. 4 , P. 477-487 Droits : 2001 Elsevier Science Inc. All rights reserved http://archimer.ifremer.fr/doc/2001/publication-650.pdf DOI:10.1016/S1532-0456(01)00274-5 http://archimer.ifremer.fr/doc/00000/650/ | Partager Voir aussi Proteins Pancreatic enzymes Lipids Larvae feeds Intestinal enzymes Glucides Fish larvae Enzyme expression Digestion Development Télécharger |
Fishery externalities and biodiversity: Trade-offs between the viability of shrimp trawling and the conservation of Frigatebirds in French Guiana Auteur(s) : Martinet, Vincent Blanchard, Fabian 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/ | Partager Voir aussi Bio-economic modeling Viability Sustainability Fishery externalities Species conservation Télécharger |
Nutrition, digestion et développement des larves de crevettes et poissons marins Auteur(s) : Cahu, Chantal Résumé : This report is presented by Chantal Cahu for obtaining accreditation to supervise research. Since 1981, her research activity has addressed the study of reproducers' nutrition and the young stages of development of marine organisms belonging to two different branch lines, crustaceans and fish. This work, performed in a base-lined research body, IFREMER, is placed within a more general programme of aquaculture development. Indeed, whatever species are at issue, the development of aquaculture in France, as at the global level, is based on the production of juveniles in hatcheries. My work has therefore more precisely the goal of acquiring knowledge about the nutritional needs, mechanisms of digestion and the development of these animals in order to improve the production of prawn post-larvae and fish alevin in the hatchery.
This work took place in three main periods that appear in this report:
- The study of reproducers' nutrition and its influence on the quality of the Penaeid prawn's eggs and larvae. My work has focused mainly on the effect of lipids and vitamins on the development of eggs and larvae.
- The study of the ontogenesis of the digestive functions and the nutritional needs of sea fish larvae, with bass as the model. The goal was to determine the specific nutritional needs of the young stages by studying the implementation and regulation of pancreatic and intestinal digestive enzymes.
- The study of the regulation of certain developmental genes by means of nutrients, so as to understand how these nutrients behave during ontogenesis, particularly during development of the skeleton.
Ce mémoire est présentée par Chantal Cahu pour pour l'obtention d'une habilitation a diriger des recherches. Depuis 1981, son activité de recherche concerne l'étude de la nutrition des reproducteurs et des jeunes stades de développement d'organismes marins appartenant à deux embranchements différents, les crustacés et les poissons. Ce travail réalisé dans un organisme de recherche finalisée, l'Ifremer, se situe dans un programme plus général de développement de l'aquaculture. En effet, quelles que soient les espèces en jeu, le développement de l'aquaculture en France comme au niveau mondial repose sur la production de juvéniles en écloserie. Mon travail a donc plus précisément pour objectif l'acquisition de connaissances sur les besoins nutritionnels, les mécanismes de digestion et le développement des ces animaux afin d'améliorer la production de post-larves de crevettes et d'alevins de poissons en écloserie. Ce travail s'est déroulé en trois grandes périodes qui apparaissent dans ce mémoire : - L'étude de la nutrition des reproducteurs et son influence sur la qualité des oeufs et des larves de crevettes Pénéides. Mon travail a essentiellement porté sur l'effet des lipides et des vitamines sur le développement des oeufs et des larves. - L'étude de l'ontogenèse des fonctions digestives et les besoins nutritionnels des larves de poissons marins, avec le bar comme modèle. Le but était de déterminer les besoins nutritionnels spécifiques des jeunes stades, en étudiant la mise en place et la régulation des enzymes digestives pancréatiques et intestinales. - L'étude de la régulation de certains gènes du développement par les nutriments, de façon à comprendre comment ces nutriments agissent lors de l'ontogenèse, notamment lors du développement du squelette. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/2006/rapport-2086.pdf http://archimer.ifremer.fr/doc/00000/2086/ | Partager Voir aussi Skeleton development Vitamins Nutriment Fish larvae Egg quality Reproduction Nutrition Shrimp larvae Peneids Télécharger |
Screening Estrogenic Activities of Chemicals or Mixtures In Vivo Using Transgenic (cyp19a1b-GFP) Zebrafish Embryos Auteur(s) : Brion, François Le Page, Yann Piccini, Benjamin Cardoso, Olivier Tong, Sok-Keng Chung, Bon-Chu Kah, Olivier Auteurs secondaires : Institut National de l'Environnement Industriel et des Risques (INERIS) 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 ) Institute of Molecular Biology (IMB Sinica) ; Academia Sinica Éditeur(s) : HAL CCSD Public Library of Science Résumé : International audience The tg(cyp19a1b-GFP) transgenic zebrafish expresses GFP (green fluorescent protein) under the control of the cyp19a1b gene, encoding brain aromatase. This gene has two major characteristics: (i) it is only expressed in radial glial progenitors in the brain of fish and (ii) it is exquisitely sensitive to estrogens. Based on these properties, we demonstrate that natural or synthetic hormones (alone or in binary mixture), including androgens or progestagens, and industrial chemicals induce a concentration-dependent GFP expression in radial glial progenitors. As GFP expression can be quantified by in vivo imaging, this model presents a very powerful tool to screen and characterize compounds potentially acting as estrogen mimics either directly or after metabolization by the zebrafish embryo. This study also shows that radial glial cells that act as stem cells are direct targets for a large panel of endocrine disruptors, calling for more attention regarding the impact of environmental estrogens and/or certain pharmaceuticals on brain development. Altogether these data identify this in vivo bioassay as an interesting alternative to detect estrogen mimics in hazard and risk assessment perspective. ISSN: 1932-6203 hal-00877371 https://hal.archives-ouvertes.fr/hal-00877371 https://hal.archives-ouvertes.fr/hal-00877371/document https://hal.archives-ouvertes.fr/hal-00877371/file/Screening_Estrogenic_Activities-accepted.pdf DOI : 10.1371/journal.pone.0036069 | Partager |
Evaluation, scénarios et viabilité écologique et économique des pêcheries côtières tropicales : application au cas de la Guyane Française Auteur(s) : Cisse, Abdoul Éditeur(s) : Université des Antilles et de la Guyane Résumé : 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. 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 multivariée 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 scenario 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. Droits : 2013 Université des Antilles et de la Guyane http://archimer.ifremer.fr/doc/00144/25492/23646.pdf http://archimer.ifremer.fr/doc/00144/25492/ | Partager |
Entre préservation et/ou mise en valeur de la ressource, quel avenir pour les Aires Marines Protégées en Province Nord de la Nouvelle-Calédonie ? Auteur(s) : Bodmer, Dolorès Éditeur(s) : Université des Antilles Études caribéennes Résumé : Cette étude permet une approche distincte de la réflexion sur les ressources marines dans le cadre d’une aire protégée. En effet, les écosystèmes marins sont essentiels d’autant plus, qu’ils présentent en Nouvelle-Calédonie une grande richesse, notamment en termes de patrimoine culturel. Ce sont majoritairement les Kanak qui habitent sur la Côte Est de la Province nord, où la Collectivité et le WWF collaborent à la mise en place de plusieurs aires marines protégées (AMP). Jusqu’à présent, la gestion coutumière Kanak a permis une relative préservation de ces écosystèmes dans un secteur littoral non soumis aux pressions de l’urbanisation, du tourisme ou de la navigation. L’étude s’attache à souligner les enjeux autour de la mise en place des AMP et des perspectives de développement local, sur le milieu marin et les populations locales. Il s’agit de voir comment cette expérimentation est envisagée par les différents acteurs (État, Province Nord, associations, coutumiers, etc.) et de s’interroger sur les mécanismes de gouvernance. This study allows a distinct approach to thinking about the marine resources in a protected area. Indeed, marine ecosystems are essential, especially as they are in New Caledonia, particularly in terms of cultural heritage. It is mainly Kanak who live on the East Coast of the North Province, where the Community and WWF collaborate on the installation of several marine protected areas (MPAs). So far, the Kanak customary management allowed a relative preservation of these ecosystems in a coastal area not subject to the pressures of urbanization, tourism and navigation. The study aims to highlight the issues surrounding the establishment of MPAs and opportunities for local development on the marine environment and local populations. This is to see how this experiment is considered by the various actors (State, Northern Province, associations, etc. customary). And to consider the mechanisms of governance. Nouvelle-Calédonie Droits : info:eu-repo/semantics/openAccess urn:doi:10.4000/etudescaribeennes.7883 http://journals.openedition.org/etudescaribeennes/7883 | Partager |
Synthesis on moored FADs in the North West Pacific region Auteur(s) : Kakuma, S Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999 Résumé : In early 1980s, fad fisheries were introduced from the Philippines to Japan, mainly to Okinawa. The fisheries have well developed becoming one of the main fisheries in Okinawa where 210 fads are approved to deploy in 1999. The annual catch by roughly 1 000 boats (most of them are small) is 2500-4000 mt; average catch from one fad is about 20 mt; average catch by one boat on one day is 73 kilogrammes. fads are also important for easing the fishing pressures on bottom fish stocks. Most of the fads were deployed and managed by local fishermen's groups that have improved the structures of the system to withstand typhoons. The catches are strongly depending on the sites, usually the farther offshore, the better the catches. A variety of fishing methods are devised targeting each species and the size of the fish. Being most abundant and having relatively higher prices, yellowfin tuna is the most important and consists 68% of the total production. There have been conflicts among fishermen on the use of fads since the early stage of the fisheries development. Now, the number of fads is regulated by a management committee. Conflicts between fishermen and sport fishermen have become problems; on the other hand, the sport fishing could lead to further development of the fisheries. Degraded fish meat caused by high meat temperature and occasional oversupply have been major marketing problems since prices are strongly related to the meat quality and the fish supply. Droits : Ifremer http://archimer.ifremer.fr/doc/00042/15281/12667.pdf http://archimer.ifremer.fr/doc/00042/15281/ | Partager |
From fleet census to sampling schemes: an original collection of data on fishing activity for the assessment of the French fisheries Auteur(s) : Berthou, Patrick Guyader, Olivier Leblond, Emilie Demaneche, Sebastien Daures, Fabienne Merrien, Claude Lespagnol, Patrick Éditeur(s) : ICES 2008 Annual Science Conference, 22-26 september 2008, HALIFAX, CANADA Résumé : The development on the ecosystem-based approach to fisheries implies to improve integrated analysis of fisheries by considering the biological as well as the socio-economic dimensions of the exploitation and thus, an improvement in the knowledge of fleets structure, evolution and activity. Since 2000, Ifremer has been implemented a Fisheries Information System (FIS), a multidisciplinary monitoring network allowing an integrated and comprehensive view of fishery systems including biological, technical, environmental and economical components. The FIS covers all the French fisheries, including the so-often neglected small-scale fisheries. One of the originalities of the FIS lies in the fleet monitoring procedure: a comprehensive collection of annual activity calendars aiming at characterizing the inactivity or activity of the vessels each month of the year and, in the latter case, the métiers practised (use of a gear to target one or several species) and the main fishing areas. This survey covers all the French fishing fleets and provides minimum but exhaustive information on the vessels. It is particularly instructive for the small-scale fisheries, where catches and effort data are often incomplete. Furthermore, this exhaustive data allows stratifying the fleet in fleets (typologies) and thus provides the basis (i) for the implementation of sampling schemes to estimate catches, landings, discards or economic performance of the different fleets and (ii) for the development of a fleet-métier matrix giving the possibility of identifying at the time, the structure of the whole fleet in fleets, the métier polyvalence of the vessels and the allocation of fishing effort on the different exploited fishing resources. Droits : 2008 ICES http://archimer.ifremer.fr/doc/00059/16996/14498.pdf http://archimer.ifremer.fr/doc/00059/16996/ | Partager |
Bilan et perspectives de developpement des DCP au Cap-Vert Auteur(s) : Rey-valette, H Martins, P Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999 Résumé : A new programme concerning the experimentation of about thirty Fish Aggregating Devices (FADs) is to start in the Cape Verde Islands at the end of 1999. In this context, this communication is intended: - to evaluate the halieutic, economic and social conditions of the artisanal fishery in this archipelago, notably in terms of assets and constraints. Although these conditions are very heterogeneous depending on islands, the fads seem to be able to help the stabilization and the development of the fishing activities, disadvantaged by a low productivity, limited operating ranges of boats, and very irregular outings at sea. But the narrowness of the domestic market is likely to cause drops in the fish prices if the production increases, while the absence of institutional framework may be a handicap at the level of the management (of the programme itself, and/or of some possible conflicts of uses); - to carry out an assessment of the former experiments. It emphasized the insufficiency of the follow-up and the maintenance of the structures, of which the lifespan varied at the most between four and six months, as well as the positive effects of the concentration, and the interest of the fishermen already sensitized with these structures. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/00042/15317/12644.pdf http://archimer.ifremer.fr/doc/00042/15317/ | Partager |
Entre conservation et développement : les évolutions récentes de la politique européenne des pêches dans les régions ultrapériphériques de la Caraïbe Auteur(s) : Angelelli, Pierre Éditeur(s) : Université des Antilles Études caribéennes Résumé : L’Union européenne opère actuellement la seconde révision de sa politique de la pêche depuis la création de celle-ci, en 1970. Instituée pour développer la pêche maritime et garantir un revenu aux pêcheurs, la politique commune de la pêche (PCP) s’est orientée progressivement vers la protection des espèces et de l’environnement marin. Pour cela, elle a sacrifié une part importante du secteur productif, mais a échoué et, avec le déclin de la pêche en Europe, les régions ultrapériphériques de la Caraïbe (RUP-C) ont gagné en importance relative dans ce domaine. Elles représentent aujourd’hui près de 30 % de la flotte nationale et les fondements malthusiens de la PCP ne sont plus adaptés à leurs caractéristiques : ressources halieutiques, développement économique, emplois, sécurité des approvisionnements alimentaires, etc. La réforme actuellement en cours, qui devrait aboutir avant 2012, offre peut-être une alternative aux RUP-C permettant la mise en œuvre des mesures spécifiques en application de l’article 349 du Traité sur le Fonctionnement de l’Union européenne. The European Union currently operates the second reform of its Common Fisheries Policy since its creation in 1970. Established to develop the fisheries and provide incomes for fishermen, the Common Fisheries Policy (CFP) was directed gradually towards the protection of the species and the marine environment. To do this, it sacrificed a large part of the productive sector, but failed, and with the decline of fisheries in Europe, the outermost regions of the Caribbean gained relative importance in this field. They now account for nearly 30% of the national fleet and the Malthusians bases of the CFP are not suited any more to their characteristics: fisheries resources, economic development, jobs, security of food supply, etc. The ongoing reform, which should be in force before 2012, may offer an alternative to the outermost regions of the Caribbean for the implementation of specific measures under Article 349 of the Treaty on the Functioning of the European Union. Caraïbes Europe Droits : info:eu-repo/semantics/openAccess urn:doi:10.4000/etudescaribeennes.4356 http://journals.openedition.org/etudescaribeennes/4356 | Partager |
Les algues sont-elles une ressource marine à exploiter pour développer durablement l’espace caribéen ? Auteur(s) : Litzler, Sophie Éditeur(s) : Université des Antilles Études caribéennes Résumé : L’algue est une ressource marine peu étudiée par la géographie ; elle offre pourtant des potentialités de développement économique. Les macro-algues cultivées à des fins alimentaires sont une alternative à la pêche. Les micro-algues constituent une biomasse valorisable : molécule pharmaceutique, Oméga 3 et biocarburants. De ces différents usages naît la question suivante : les algues sont-elles une ressource marine à exploiter pour développer durablement les territoires de la zone intertropicale ? Nous présenterons tout d’abord l’algoculture à l’échelle mondiale en soulignant le faible poids de cette activité dans le bassin caribéen. Puis nous montrerons que l’algoculture s’inscrit dans un processus de développement durable en assurant un revenu à des communautés rurales (Petites Antilles). Enfin, dans une approche comparative (États-Unis), nous verrons que l’espace caribéen est une région de projets et d’aménagements durables qui a des atouts pour développer l’algoculture : exposition solaire, hautes températures, proximité de la recherche américaine. Algae as sea resource have not been largely explored in Geography, yet it offers the potential for economic development. Macro-algae are cultivated for food purposes and they can substitute for fishing. Micro-algae can be valued as biomass: “nutraceutics”, Omega 3, biofuel. These various utilizations raise a question: are algae a key to a sustainable development in intertropical islands? We shall present Algaculture on a global scale, while emphasizing its low importance in the Caribbean. Then we shall show how algaculture can be part of a process of sustainable development by providing revenue to rural communities (Lesser Antilles). Finally, in a comparative approach (with the US), we shall see that the Caribbean Region has a number of assets for algaculture that make it suitable for sustainable projects and infrastructures: solar exposure, high temperatures, close to the US research centers. États-Unis Caraïbes Droits : info:eu-repo/semantics/openAccess urn:doi:10.4000/etudescaribeennes.4389 http://journals.openedition.org/etudescaribeennes/4389 | Partager |
Inventaire des plantes introduites en Méditerranée : origines et répercussions sur l'environnement et les activités humaines Auteur(s) : Verlaque, M Éditeur(s) : Gauthier-Villars Résumé : This review addresses the problem of recently introduced plants in the Mediterranean in order to analyse their vectors, the dispersal processes and the possible ecological and economic consequences. Ninety-five cases (94 macroscopic algae and one seagrass) are listed and discussed. Three major routes of access into the Mediterranean are indicated: shipping, the Suez canal and aqua-culture. The recent introduction of Caulerpa taxifolia along our coasts has called attention to a new potential source: aquaria. Among the successful acclimatizations, cold-temperate Pacific and Atlantic species remain confined to the north of the Mediterranean (Gulf of Lions, Adriatic), whereas some tropical or sub-tropical plants colonize large areas. Some introduced algae proliferate to the detriment of the indigenous Mediterranean vegetation. In contrast with some terrestrial introductions, no population crash has been observed in the Mediterranean, although some notable fluctuations seem to occur in coastal lagoons. From an economic point of view, the two activities most affected by this phenomenon are aquaculture and fishing. With the gradual disappearance of European frontiers, the worldwide development of marine cultures and the multiplication of giant Seaworlds, the transfer of live marine organisms will become routine and the risk of new introductions will considerably increase in the Mediterranean. Only international legislation, established by the countries of the littoral, will be able to control these problems. Oceanologica Acta (0399-1784) (Gauthier-Villars), 1994 , Vol. 17 , N. 1 , P. 1-23 Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/00098/20879/18493.pdf http://archimer.ifremer.fr/doc/00098/20879/ | Partager Voir aussi MEDITERRANEAN INTRODUCED SPECIES MARINE ALGAE SEAGRASSES ECOLOGICAL AND ECONOMIC CONSEQUENCES Télécharger |
Guam Fish Aggregating Device programme Auteur(s) : Torres, A Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999 Résumé : Installation and maintenance of FADs by the Government of Guam began in 1979, initially with funding from the Salstonstall-Kennedy Act through the Pacific Tuna Development Foundation. Current funding for the Guam FAD project is provided through the Dingell-Johnson/Wallop-Breaux Sport Fish Restoration programme, a Federal Aid Project funded by taxes collected on the purchase of fishing equipment and motorboat fuels nationwide. There are now sixteen operational FAD sites in Guam's waters. At a cost of approximately US$10,000 per system, concern for the rising costs of replacing and maintaining FAD systems has prompted the Department of Agriculture's Division of Aquatic and Wildlife Resources (DAWR) to investigate alternative FAD maintenance strategies and system design. Several cost-cutting measures being considered include the use of reliable solar-powered navigation lights to reduce the number of maintenance trips required, and switching to a newer generation of lighter, more durable buoys and mooring systems. Average time on station for a dawr fad system is nearing two years. Interestingly, in most cases where an errant system is recovered, the failure in the mooring system was observed to occur at a depth from 35 to 500 metres. These observations have led to speculation that additional protection of the mooring line down to 500 m may result in doubling the average time on station of most FAD systems. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/00042/15324/12650.pdf http://archimer.ifremer.fr/doc/00042/15324/ | Partager |
Pêche thonière et dispositifs de concentration de poissons Auteur(s) : Le Gall, Jean-yves Cayre, Patrice Taquet, Marc Éditeur(s) : Actes de colloque Ifremer n°28, 2000. ISBN-13 978-2-84433-047-5 ISBN-10 978-2-84433-047-5 Résumé : The international symposium "Tuna Fishing and Fish Aggregating Devices " , October 1999, in Martinique, takes stock of the exploitation of large pelagic fish around FADs, based on regional synthesis for the three oceans and the Mediterranean Sea. Main themes include technology, fishing methods, impact on resources, biology of fish aggregation, anthropology and economic aspects of FAD exploitation. The meeting will gather and disseminate results from recent and ongoing studies on FADs in the different oceans of the world, enhance collaboration between scientists and managers involved in the development of FADs, promote the emergence of scientific and technical research, form a network for cooperation and enhance communications between researchers in the different locations concerned. Le colloque international « Pêche thonière et dispositifs de concentration de poissons» organisé en octobre 1999, en Martinique, permet de dresser un bilan, sous forme de synthèses régionales, de l'exploitation des grands poissons pélagiques à l'aide de DCP dans les trois océans et en Méditerranée. La technologie, les méthodes de pêche, l'impact sur les ressources, le comportement agrégatif des poissons et les aspects socio-économiques de l'utilisation des DCP sont les principaux thèmes développés. Ces travaux permettront d'assurer une diffusion large des résultats à l'échelle de l'océan mondial, de favoriser les échanges entre les scientifiques et les gestionnaires impliqués dans le développement des systèmes DCP, de promouvoir l'émergence de thèmes et projets de recherche scientifique et technologique, de mettre en oeuvre un réseau de communication et d'échanges entre les sites et les régions concernées. Droits : 2000 Ifremer http://archimer.ifremer.fr/doc/00042/15326/12646.pdf http://archimer.ifremer.fr/doc/00042/15326/ | Partager |