Éditeur(s) : Edp Sciences S A
Résumé : This paper provides an overview of the progress Ifremer has made recently in fisheries acoustics and the study of small pelagic fish by: i) pushing observation frontiers using a range of platforms including an autonomous underwater vehicle, AUV, ii) developing measuring instruments and methods and iii) studying fish distributions. Presently, information from several frequencies of single-beam echosounders is routinely collected together with data from the ME70 multibeam echosounder. For onboard data acquisition control the HERMES software was developed. The new MOVIES 3D software includes modules for simultaneous realistic 3D visualisation and post-processing such as bottom detection, school extraction and calculation of descriptors and integration of all acoustic data. Several data analysis methods are being developed and some initial results are presented. Finally, results on the spatial distribution of small pelagic fish schools in the Bay of Biscay illustrate the role that acoustics can play, and are already playing, in the implementation of an ecosystem approach to fisheries.
Cet article présente une vue d’ensemble des avancées récentes de l’Ifremer en acoustique halieutique et une étude des petits poissons pélagiques tenant compte : i) de l’extension des limites de l’observation, en utilisant une gamme diverse de plates-formes dont un engin sous-marin autonome (AUV), ii) des développements méthodologiques et d’instruments de mesures, iii) de l’étude de la répartition des poissons. Désormais, les données de plusieurs fréquences des sondeurs mono-faisceaux sont collectées en routine en parallèle à celles du sondeur multifaisceau ME70. Le logiciel HERMES a été développé pour le contrôle de l’acquisition des données à bord. Le nouveau logiciel MOVIES 3D comprend des modules de visualisation réaliste en 3D et de post-traitement (dont la détection du fond, l’extraction de bancs et le calcul de leurs descripteurs ainsi que l’intégration de toutes les données acoustiques). Plusieurs méthodes d’analyse de données sont en cours de développement et quelques premiers résultats sont présentés. Enfin, les résultats relatifs à la répartition spatiale des bancs de petits poissons pélagiques dans le golfe de Gascogne illustrent le rôle actuel et potentiel de l’acoustique dans la mise en place d’une approche écosystémique des pêches.
Aquatic Living Resources (0990-7440) (Edp Sciences S A), 2009-10 , Vol. 22 , N. 4 , P. 433-445

Droits : EDP Sciences, IFREMER, IRD 2009
http://archimer.ifremer.fr/doc/00000/11165/7517.pdf
DOI:10.1051/alr/2009027
http://archimer.ifremer.fr/doc/00000/11165/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : Approximately 4,000 petroleum (oil and gas) platforms exist in the northern Gulf of Mexico and form one of the world's most extensive de facto artificial reef systems. Collectively, these structures may comprise one of the largest fad (Fish Aggregating Device) arrays in the world, attracting surface and midwater pelagic fishes. The diverse composition of pelagic fish fauna at ngom platforms is described and includes valued species such as Thunnus albacares, Thunnus atlanticus, Coryphaena hippurus, Acanthocybium solandri, Rachycentron canadum, Seriola dumerili, Scomberomorus cavalla, and Decapterus punctatus. Petroleum platforms influence pelagic fishery resources and are an important component of the Gulf's commercial and recreational fishing industries. Reviewed literature revealed a sparsity of fundamental knowledge of densities, temporal and spatial occurrence, and fishing effort/catch rates of pelagic fishes at platforms. The role of Gulf petroleum platforms "as fads" is examined, possible mechanisms for aggregation are reviewed, and a synopsis of the author's preliminary findings on life history aspects of A. solandri and R. canadum from platforms is presented. It is proposed that platforms provide opportunities for the study of pelagic species to better understand the life history, ecology, behaviour, and habitat requirements of pelagic fishery resources in the Gulf of Mexico.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15301/12633.pdf
http://archimer.ifremer.fr/doc/00042/15301/

Éditeur(s) : Kluwer
Résumé : We reviewed the literature concerning fish aggregation devices (FADs) to determine areas of relative research deficiency. Using specific searches of the Aquatic Sciences and Fisheries Abstracts ( ASFA) database from 1978 to December 2003 and a classical search of the pre-1978 literature, we collected 407 references on FADs. Publications before 1980 were predominantly peer-reviewed, although non-peer reviewed literature has dominated since 1980, due to the numerous technical reports produced as FADs became more widely used in artisinal and large-scale industrial. sheries in the 1980s. Most studies of the ecology of FAD-associated fish were descriptive, with few mensurative experimental studies and even fewer manipulative experimental studies that tested specific hypotheses, due to inherent difficulties in working in the open ocean on objects that are temporary in space and time. Research on the ecology of FAD-associated fish has focused on moored FADs, despite the major FAD-based. sheries being around drifting FADs. Publications presenting information on moored FADs outnumbered papers on drifting FADs by a ratio of 3.5: 1. We recommend that greater emphasis be placed by. sheries scientists and funding agencies on researching drifting FADs to provide better information for management of large-scale FAD-based industrial. sheries. Future research should focus on determining the patterns of use of drifting FADs by pelagic species, the underlying sensory processes of attraction and the ecological consequences for individual fish stocks and the wider pelagic ecosystem of the use of FADs as. sheries enhancement tools.
Reviews in Fish Biology and Fisheries (0960-3166) (Kluwer), 2004-03 , Vol. 14 , N. 1 , P. 21-42

Droits : 2004 Springer
http://archimer.ifremer.fr/doc/2004/publication-721.pdf
DOI:10.1007/s11160-004-3151-x
http://archimer.ifremer.fr/doc/00000/721/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : Tuna world fisheries yield 3 million tons per year; the increase rate of whole production is constant and sustained since 30 years. This original figure for marine fisheries is due to enlargement of tuna fleets and fishing grounds over all the world ocean, the continuous increase of tuna fishing power by in board equipment and remote sensing equipment for searching and scouting (on board, aircraft, satellite, telecommunication_). During the last 20 years, the log-associated tuna fishing has contributed to the local individual and tuna fleets efficiency and fishing power either for large industrial tuna seiners by radio-equipped buoys on natural (debris) or artificial man-made logs. The same trend is noted for numerous artisanal tuna and large pelagic coastal fisheries on moored fishing aggregating devices and networks. The first part of the paper is a review of data and results to assess and rank the "Surfaces prospected by in board tuna seiners and associated aircraft and satellite technics" (visual, radar, sar-radar and satellite altimetry sensors). The final objective is the comparison with the surfaces and volumes associated to fads. Since 20 years, tuna ecology and behaviour data from ultrasonic tagging (short-term depth/distance/time migration around logs and fads) are used for fishing of tuna associated with floating objects, namely fads. The second part of this paper is an "Assessment of fad's aggregating associated surface and volume" linked with oceanographic data: large oceanic geostrophic current and observed drift speed of radio-equipped fads in the Indian Ocean. Using the available data on fads, tuna fishing technology linked with oceanographic and biological data results from ultrasonic tuna tracking experiments, the paper is an attempt to identify and place the fads technology in the scale of tuna fishing devices as a contribution to the increase of tuna fishing power either individual tuna boat or tuna fleets.Original Abstract: La production mondiale des pecheries thonieres est actuellement de l'ordre de 3 millions de tonnes par an et conserve depuis pres de 50 ans un taux de croissance annuel soutenu. Cette croissance, exceptionnelle pour un secteur des peches maritimes, est due a plusieurs causes: accroissement des effectifs et des puissances de peche des grandes flottes thonieres industrielles oceaniques qui exploitent les ressources thonieres de l'ocean mondial et le developpement conjoint de nouvelles techniques de peche et de nouvelles technologies d'aide a la peche, telles que les dispositifs de concentration de poissons (DCP). L'accroissement de la puissance individuelle des navires est du au developpement de la construction navale (mecanisation, propulsion, hydraulique, conservation et traitement a borda) et a l'utilisation d'une gamme diversifiee d'aides a la peche : navigation, telecommunication, localisation des zones favorables, detection visuelle ou radiometrique assistee par equipement a bord, en helicoptere et avion, detection acoustique, detection par radar de bord, radar-avion ou, a terme, antenne SAR sur satellite. Plus recemment, soit depuis 20 ans, les caracteristiques du comportement, migration de court terme, agregation et concentration des poissons pelagiques, fixation et retention des bancs de thons, sont utilisees, par les dispositifs de concentration de poissons (DCP) ancres ou derivants. Cette contribution a pour objectif de situer et placer les DCP fixes ou derivants sur cet ensemble de techniques d'aide a la peche thoniere. Les donnees pour cet essai de classement sont d'ordres biologique, ethologique et comportementaux (amplitude de deplacement des thons et dimension de la sphere d'attraction d'un DCP) et d'ordres environnemental et oceanographique : masse d'eau concernee par un DCP dans une large veine de courant oceanique ou cotier. On tente de quantifier et d'ordonner les surfaces et les volumes prospectes par les thoniers et particulierement les volumes et masses d'eau exploites par les thoniers utilisant des DCP. Ce classement des DCP dans la serie des dispositifs d'aide a la peche thoniere facilitera l'appreciation de leur contribution a l'augmentation des puissances de peche des thoniers.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15297/12656.pdf
http://archimer.ifremer.fr/doc/00042/15297/

Éditeur(s) : HAL CCSD
Résumé : Integrating ecological connectivity into marine ecosystem management and planning is important, especially in a global context of severe fish stocks depletion and growing habitat degradation. Environmental tools such as Marine Protected Areas have been proposed to protect biodiversity, restore damaged ecosystems, sustain fisheries, and rebuild overexploited stocks. The effectiveness of marine protected areas depends in part on the maintenance of connectivity between marine populations, linked by ecological processes such as larval dispersal. In this thesis, we applied a biophysical model driven by ocean currents derived from satellite altimetry to evaluate connectivity between Western Indian Ocean reefs and across the current MPA system in the Mediterranean Sea. We applied different methods of analysis such as graph-theoretic and clustering. In the Western Indian Ocean, marine connectivity analyses show that the number of connections between reefs increases with fish pelagic larval duration. It also highlights a low connectivity across the region and a high interconnectivity within several regions (Mozambique Channel, Mascarene archipelago). In the Mediterranean Sea, connectance is globally low at the regional scale. This connectance is more important in Western than Eastern Mediterranean. Moreover, the marine connectivity analyses revealed high domestic connectivity rates. Depending on the study area, priority reefs or sites for MPA implementation are proposed. Finally, implications for transboundary marine policies and regional cooperation are discussed.
Intégrer les connaissances sur la connectivité écologique dans la gestion des écosystèmes marins est essentiel, surtout dans un contexte d'appauvrissement des ressources marines et de dégradation des habitats côtiers à l'échelle mondiale. Des outils environnementaux, tels que les Aires Marines Protégées ont été mises en œuvre pour protéger la biodiversité, restaurer les écosystèmes endommagés, soutenir les pêcheries et reconstituer les stocks surexploités. Leur efficacité dépend en partie du maintien de la connectivité entre les populations marines, assurée à travers divers processus écologiques dont la dispersion larvaire. Dans le cadre de ce travail de thèse, un modèle biophysique intégrant des données de courants, issues de mesures d'altimétrie par satellite, a été utilisé pour évaluer la connectivité entre les récifs de l'océan Indien d'une part, et à travers le réseau d'AMP de Méditerranée d'autre part. Différentes méthodes d'analyse ont été utilisées, telles que la théorie des graphes et le clustering. Dans l'océan Indien occidental, l'analyse des connectivités marines montre que le nombre de connexions entre les récifs augmente avec la durée de vie larvaire des poissons. Elle met également en évidence une faible connectivité à l'échelle de la région, mais une forte inter-connectivité au sein de plusieurs sous-régions (Canal du Mozambique, Mascareignes). En Méditerranée, la connectance est globalement faible à l'échelle régionale, bien que plus importante dans le bassin occidental que le bassin oriental. L'analyse des connectivités marines montre également un taux de connectivité élevé à l'échelle d'un même pays. Selon le cas d'étude, une liste de récifs ou de sites prioritaires dans la mise en œuvre des AMP a été proposée. Enfin, les implications de ces résultats en termes de politiques transfrontalières et de coopération régionale sont discutées.
https://tel.archives-ouvertes.fr/tel-01269631

NNT : 2015LARE0003
tel-01269631
https://tel.archives-ouvertes.fr/tel-01269631
https://tel.archives-ouvertes.fr/tel-01269631/document
https://tel.archives-ouvertes.fr/tel-01269631/file/2015lare0003_ECrochelet.pdf

Éditeur(s) : EDP Sciences
Résumé : From April 2003 to April 2004 monthly sea surveys were conducted around 2 fish aggregating devices (FADs) moored at 2000 and 2500 m depth in Martinique (Lesser Antilles). The use of a dual frequency splitbeam echosounder combined with an underwater camera and fishing methods allowed assessment of average space and time distribution of pelagic fish aggregated beneath the FADs, as well as identification of their overall size and species composition. At daytime, 4 fish aggregations were identified at each FAD, representing 4 distinct types: i) an aggregation of small juvenile tuna (mean fork length, FL: 30 cm) observed very close to the surface in 25% of daytime periods; ii) a small surface aggregation dominated by carangids, Caranx crysos, present in 65% of daytime periods; iii) a large sub-surface aggregation observed during all daytime periods: this aggregation appeared to be primarily comprised of 58 cm FL blackfin tuna (Thunnus atlanticus), mixed with yellowfin (Thunnus albacares) and skipjack (Katsuwonus pelamis) tunas of the same size; and iv) sub-surface scattered large predators (mainly blue marlin, Makaira nigricans) present in 10% of daytime periods. A smaller sub-surface aggregation comprised of medium tuna mixed with "extranatants" (fishes which remain within 10 to 50 m of a FAD) was observed in 75% of night-time periods, whereas unidentified scattered fishes were detected from 70 to 400 m depth. The low daytime vulnerability of medium sub-surface tunas to applied line techniques leads us to assume that their feeding motivation was low during daytime. These tunas could preferentially feed on mesopelagic organisms during night-time and transition periods around Martinican moored FADs. Local fishermen mainly targeted the large scattered predators using very small tunas as living bait. The sub-surface tuna aggregation hence appeared to be currently unexploited by local fisheries, though it represented the large majority of the pelagic biomass around the moored FADs.
Des campagnes scientifiques mensuelles ont été menées autour de 2 dispositifs de concentration de poissons ancrés à 2000-2500 m de profondeur, en Martinique d'avril 2003 à avril 2004. L'utilisation combinée d'un échosondeur monofaisceau multifréquence, d'une caméra vidéo sous-marine et de techniques de pêche conventionnelles a permis de déterminer la distribution spatio-temporelle moyenne des poissons agrégés autour des DCP ancrés ainsi que la composition générale des agrégations. Les techniques de vidéo sous-marine ont joué un rôle majeur dans l'identification des espèces et l'observation de leur comportement. De jour; quatre types d'agrégations ont été définis : i) une agrégation de thonidés juvéniles (longueur à la fourche, LF, moyenne : 30 cm) observée très près de la surface durant 25 % des périodes diurnes échantillonnées ii) une petite agrégation composée essentiellement de Caranx crysos présente en surface lors de 65 % des phases diurnes iii) une grande agrégation de thons observée en sub-surface lors de toutes les phases diurnes; cette agrégation était constituée essentiellement de thons noirs (Thunnus atlanticus) de 58 cm LF, associés de façon saisonnière à des albacores (Thunnus albacares) et des listaos (Katsuwonus pelamis) de taille similaire iv) des grands prédateurs assez dispersés (essentiellement le marlin bleu, Makaira nigricans), observés lors de 10 % des phases diurnes. Une agrégation de sub-surface, aux dimensions plus réduites et composée de thons et "d'extranatants" (poissons restant à distance de 10 à 50 m du DCP) a été observée lors de 75 % des périodes nocturnes; ainsi que des organismes non-identifiés dispersés entre 70 et 400 m de profondeur. La faible vulnérabilité diurne des thons de sub-surface aux techniques de ligne utilisées indique qu'ils ne se nourrissent pas activement durant la journée. Ces poissons pourraient se nourrir préférentiellement d'organismes mésopélagiques durant les phases de transition et nocturnes autour des DCP ancrés. La pêcherie artisanale martiniquaise n'exploite qu'une faible part des ressources agrégées autour des DCP ancrés. Les principales espèces-cibles sont les grands prédateurs capturés de jour en utilisant des thonidés juvéniles comme appât vivant. L'agrégation de thons de sub-surface représente la grande majorité de la biomasse autour des DCP mais elle est quasiment inexploitée par les pêcheries locales.
Aquatic Living Resources (0990-7440) (EDP Sciences), 2007-10 , Vol. 20 , N. 4 , P. 357-366

Droits : EDP Sciences, IFREMER, IRD 2007
http://archimer.ifremer.fr/doc/2007/publication-3634.pdf
DOI:10.1051/alr:2008004
http://archimer.ifremer.fr/doc/00000/3634/

Éditeur(s) : Université de Bretagne Occidentale
Résumé : Several small pelagic fish species contribute remarkably to world catch. Their populations are, however, characterized by large biomass fluctuations strongly affecting fisheries. The fishing gears and methods used to capture small pelagics have evolved to exploit the highly developed shoaling behavior of these species. Hence, faced to modern fishing this gregarious behavior becomes a disadvantage for fish. Fish behavior may be affected by environmental conditions and by fishing, at the same time that behavior impacts fishing. In this study, we seek to characterize the aggregative systems of small pelagic fishes inhabiting the Bay of Biscay by analyzing "acoustic images", defined as the group of echoes (planktonic layers, shoals, isolated targets) detected on a transect section of a given length. We analyzed the species composition, the spatial distribution and the evolution over time of acoustic images. We also studied the hydrological conditions of the bay, as well as the small pelagics French fishery in order to look for correlations between hydrology, commercial catch and fish aggregation patterns observed by acoustics. We observed the same species or group of species forming different types of aggregation according to habitat. Conversely, the same type of aggregation, associated with a particular habitat, can be produced by different species. The most notorious change observed during the studied period relates to small clupeoids aggregations in the vicinity of the Gironde estuary, whose structure evolved toward a greater fragmentation of shoals (a large number of small size detections) since 2000. Concerning commercial catches, pelagic trawlers fishing in pairs mainly seek for anchovy in the coastal areas, single pelagic trawlers capture mackerel and horse mackerel in deeper waters while purse seiners target mostly sardine near their fishing ports. Because of the coarse spatial resolution of commercial fishing data and the effect of the application of an international fisheries agreement limiting the fishing activity of French pelagic trawlers during spring, only small correlations between captures and types of aggregation were observed.
La participation des petits poissons pélagiques dans les captures est remarquable. Leurs populations sont cependant caractérisées par des importantes fluctuations de biomasse, impactant fortement les pêcheries. Les méthodes et appareils de pêche utilisés pour capturer ces espèces ont évolué dans le sens d'exploiter le comportement grégaire très développé des petits pélagiques. Cette tendance à former de bancs devient alors désavantageuse pour le poisson face à la pêche moderne. Les conditions environnementales et la pêche peuvent affecter le comportement du poisson, en même temps que ce dernier est susceptible d'affecter l'activité halieutique. Le but de cette étude est de caractériser les systèmes agrégatifs des petits poissons pélagiques dans le golfe de Gascogne en étudiant des « images acoustiques », définies comme l'ensemble des échos (couches planctoniques, bancs, cibles isolées) détectés sur une section de radiale de longueur donnée. Nous analysons leur composition en espèces ainsi que leur distribution spatiale et leur évolution au cours du temps. Nous étudions aussi les conditions hydrologiques du golfe, ainsi que la pêcherie française de ces espèces afin de chercher des corrélations entre l'hydrologie, la capture commerciale et les types d'agrégations observés par acoustique. Nous avons observé qu'une espèce est capable de former des agrégations différentes en fonction de l'habitat, et inversement, le même type d'agrégation, associé à un habitat particulier, peut être produit par des espèces différentes. Le changement observé le plus évident concerne les agrégations de petits clupéiformes, dont la structure a évolué vers une plus grande fragmentation des détections (des petits bancs plus nombreux) depuis 2000. Par rapport à la pêche des professionnels, les chalutiers pélagiques en boeufs recherchent en priorité l'anchois dans la zone côtière, les pélagiques simples capturent le chinchard et le maquereau au large et les senneurs recherchent principalement la sardine à proximité des ports de pêche. À cause de la résolution spatiale trop sommaire des données de pêche et l'effet de l'application des accords internationaux limitant l'activité des chalutiers pélagiques au printemps, nous n'avons observé que peu des corrélations entre les captures et les types d'agrégation établis à partir de données issues des campagnes scientifiques.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2008/these-6083.pdf
http://archimer.ifremer.fr/doc/00000/6083/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : Since 1980 a programme of Fish Aggregation Device (fad) deployment has been carried out in the Cook Islands. Government has deployed all fads between 1 to 3 nautical miles from shore at depths ranging from 800 to 1,600 metres. The fads have undergone various designs with varying degrees of success. The average fad lifespan during the early 1980s was nine months; however, it increased to 18 months, with some fads in operation in excess of 30 months. Each fad cost between nz$ 7,000 and nz$ 9,000 to build and deploy. Since their introduction, fad have been widely accepted as a very effective apparatus in coastal small-scale fishing activities, specifically for pelagic species. Judging by the progressive behaviour of local fishing communities, there is sufficient reason to believe that fads have created productive fishing zones for Cook Islands fishermen to enable them to supply the ever-increasing local market for fresh fish. fads are an integral part of local fishing communities and provide a reasonable form of income to the increasing fishing community.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15323/12654.pdf
http://archimer.ifremer.fr/doc/00042/15323/

Éditeur(s) : Oxford university press
Résumé : There is increasing evidence from previous studies, and from fishers' observations, that coastal dolphins use fishing nets as an easily accessible feeding source, damaging or depredating fish caught in the nets. This study investigates the impact of dolphin depredation on artisanal trammelnets by analysing the catch composition of 614 artisanal fishing operations in the Bonifacio Strait Natural Reserve (France). Common bottlenose dolphins (Tursiops truncatus) attacked, on average, 12.4% of the nets and damaged 8.3% of the catch. However, attacked nets were characterized by statistically significantly higher catch per unit effort than unattacked ones. Catch composition also differed significantly after dolphin attacks; bentho-pelagic fish were more represented and reef-associated fish less represented. Our results suggest that (i) dolphins are attracted by high fish densities in the fishing area and/or nets, and (ii) their attacks induce specific fish-avoidance behaviour, according to the fish position in the water column. Although dolphins depredate a small part of the catch, damage to nets, not yet assessed in this area, could weaken the benefits that reserves can provide to artisanal fisheries.
ICES Journal of Marine Science (1054-3139) (Oxford university press), 2009-05 , Vol. 66 , N. 4 , P. 699-707

Droits : 2009 ICES/CIEM. Oxford Journals
http://archimer.ifremer.fr/doc/2009/publication-6808.pdf
DOI:10.1093/icesjms/fsp036
http://archimer.ifremer.fr/doc/00000/6808/

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/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : Since a few years, the catches of pelagic fish by artisanal fishermen of Reunion Island have strongly increased. Manpower and investments have been constant through the maintenance of about 30 fads all around the island. The traditional techniques of fishing pelagic fishes have been adapted in order to maintain a high level of catches and ensure the income of the fishermen. This report describes different techniques to capture pelagic fish on fads such as drift fishing, dragnet fishing and longline fishing. Knowledge, professional experience of fishermen are the main factors in setting fads and sustaining adaptability. The strong relation between the knowledge of the fishermen and the techniques is discussed. Then, the strategies of fishing, influenced by the environmental and seasonal conditions, and the species, are analysed.Original Abstract: L'activite de la petite peche a l'ile de La Reunion connait, depuis quelques annees, une periode d'expansion rapide de la production de poissons pelagiques. Ce developpement est d'autant plus remarquable qu'il s'effectue, en ce qui concerne la peche professionnelle artisanale, a effectif et investissement presque constants. Il est essentiellement du a la mise en place et a l'entretien d'un parc d'une trentaine de dispositifs de concentration de poissons (DCP), places tout autour de l'ile. Les techniques traditionnelles de peche de poissons pelagiques ont ete adaptees a ce nouveau concept, mais elles doivent continuellement evoluer et s'adapter aux modifications comportementales des poissons, afin de maintenir un niveau de capturabilite assurant les revenus des pecheurs. Cette etude s'attache a decrire les techniques de peche a la derive, a la traine et aux palangres, employees pour la capture de poissons pelagiques sur DCP. Bien que difficile a evaluer, l'experience du pecheur est un facteur determinant dans la mise en uvre de ces techniques et en permet l'amelioration constante. L'imbrication etroite entre le savoir-faire du pecheur et les techniques est egalement abordee et discutee. Enfin, les strategies de peche, fortement influencees par les conditions environnementales, les saisons et les especes rencontrees, y sont analysees.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15294/12652.pdf
http://archimer.ifremer.fr/doc/00042/15294/

Éditeur(s) : The National Academy of Sciences of the USA
Résumé : The patterns of variations in fisheries time series are known to result from a complex combination of species and fisheries dynamics all coupled with environmental forcing (including climate, trophic interactions, etc.). Disentangling the relative effects of these factors has been a major goal of fisheries science for both conceptual and management reasons. By examining the variability of 169 tuna and billfish time series of catch and catch per unit effort (CPUE) throughout the Atlantic as well as their linkage to the North Atlantic Oscillation (NAO), we find that the importance of these factors differed according to the spatial scale. At the scale of the entire Atlantic the patterns of variations are primarily spatially structured, whereas at a more regional scale the patterns of variations were primarily related to the fishing gear. Furthermore, the NAO appeared to also structure the patterns of variations of tuna time series, especially over the North Atlantic. We conclude that the patterns of variations in fisheries time series of tuna and billfish only poorly reflect the underlying dynamics of these fish populations; they appear to be shaped by several successive embedded processes, each interacting with each other. Our results emphasize the necessity for scientific data when investigating the population dynamics of large pelagic fishes, because CPUE fluctuations are not directly attributable to change in species' abundance.
Proceedings of the National Academy of Sciences of the United States of America (0027-8424) (The National Academy of Sciences of the USA), 2008-04 , Vol. 105 , N. 14 , P. 5420-5425

Droits : 2008 by The National Academy of Sciences of the USA
http://archimer.ifremer.fr/doc/2008/publication-3984.pdf
DOI:10.1073/pnas.0709034105
http://archimer.ifremer.fr/doc/00000/3984/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : For most fisheries, increasing the local production of pelagic fish is the main objective of Fish Aggregating Devices (fads). This does not rule out the existence of a larger-scale impact, especially on the migratory behaviour of fish. The analysis of data collected during 25 experimental fishing surveys around Martinique between 1995 and 1997 has led to the hypothesis that fads influence the migratory behaviour of young dolphinfish. Unlike recent studies of dolphinfish migration in the Caribbean, which tend to show an annual migration pattern with a seasonal passage through the French West Indies, the experimental fishing surveys done over more than a year on a monthly basis on a single cohort, show that the migratory pattern of part of the regional stock could be disrupted. This analysis has made it possible to estimate an average growth rate for this species during the first year of life.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15321/12635.pdf
http://archimer.ifremer.fr/doc/00042/15321/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : Fishing with a beach seine for catching small pelagic fishes is a traditional activity in Martinique. Since the early eighties, an important decrease in the number of fishermen practising this activity has been recorded. In the context of high exploitation of reef resources, the beach seine presents a low selectivity, catching too many juveniles of demersal fish. The fads established in coastal areas, have been successfully used in others regions of the world for exploiting small pelagics. Thus, it could allow to favour a change of exploitation style of these resources in Martinique. In partnership, Ifremer, the Regional Council and the Fishing Committee have began an evaluation of the potentialities for this type of structures around the island. To achieve this study, several experimental coastal fads have been established in different places. Surveys by subaquatic observations are periodically carried out to compare the attractive power of different aggregation devices (colour, shape, volume) and understand the factors influencing the determinism of the aggregation (biotic and abiotic). The results presented and discussed correspond to the initial stage of this study which should be pursued in the next months.Original Abstract: La peche a la senne de plage pour la capture des petits poissons pelagiques est une activite halieutique traditionnelle et ancienne en Martinique. Depuis le debut des annees quatre-vingt, une diminution importante du nombre de pecheurs pratiquant cette activite est enregistree. Les dispositifs de concentration de poissons (DCP) implantes en zone cotiere sont abondamment utilises dans d'autres regions du monde avec succes. Ils pourraient donc permettre de redynamiser ce secteur en Martinique. L'Ifremer, le conseil regional et le comite des peches ont entrepris, en partenariat, une etude permettant d'evaluer les potentialites du developpement de ce type d'amenagement autour de l'ile. Pour realiser cette etude, plusieurs DCP cotiers experimentaux ont ete implantes dans differents sites. Ils font l'objet d'un suivi halieutique base sur les comparaisons des captures realisees par les professionnels sur et hors DCP. En parallele, des campagnes d'observations sous-marines sont effectuees de facon periodique. Elles permettent d'une part de comparer les pouvoirs attractifs de differents dispositifs d'agregation (forme, volume, couleur) et, d'autre part, de mieux comprendre les facteurs biotiques et abiotiques influencant le determinisme de l'agregation. Les resultats presentes et discutes correspondent a la phase initiale de l'etude qui doit se poursuivre dans les prochains mois afin de couvrir toute la saison de peche.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15302/12634.pdf
http://archimer.ifremer.fr/doc/00042/15302/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : This summary tackles the development of fisheries in the Caribbean using fads. It highlights the principal causes which explain why, in spite of more than thirty years of experimenting, fishing on fads has not developed as much as had been hoped. Whereas the deep-sea production of pelagic fish by the continental countries of the region has considerably increased since the early eighties, that of the Lesser Antilles has grown more slowly. Anchored fads have given the boats of the small-scale fisheries from three islands (Guadeloupe, Martinique and Curacao) access to these pelagic resources. The various modes of development and management of the fads observed in each island are described. The first available data are used to provide some indications of the effects of the various strategies implemented and the changes induced by this new fishing technique.Original Abstract: Cette synthese concerne la region Atlantique Centre-Ouest (FAO 31) mais elle aborde principalement le developpement des DCP ancres de la zone Caraibe. Trois sites principaux font l'objet d'un developpement particulier ; il s'agit des iles pour lesquelles l'activite de peche professionnelle est actuellement effective autour des DCP : la Guadeloupe, la Martinique et Curacao. L'introduction de DCP dans l'Atlantique Centre-Ouest est signalee pour la premiere fois en 1969, a Panama City (Floride). Il s'agit alors de dispositifs cotiers. Les especes ciblees sont des petits poissons pelagiques. Au debut des annees quatre-vingt, l'implantation de DCP ancres autour des petits etats insulaires de la Caraibe pour la peche des grands poissons pelagiques est consideree comme une priorite par les scientifiques reunis lors du 36e congres du Gulf and Caribbean Fisheries Institute (GCFI). Beaucoup d'experiences DCP conduites dans la region ont permis de conclure a une bonne efficacite agregative quels que soient les choix technologiques operes (DCP lourds ou legers). Malgre cela, tres peu d'iles tirent actuellement benefice de l'avantage que procurent les DCP pour l'exploitation des ressources en grands pelagiques frequentant leurs eaux. Les problemes de transfert et les difficultes a passer de la phase experimentale a la phase operationnelle sont probablement a l'origine de ce paradoxe. Le developpement d'une reelle cooperation regionale sur le theme devrait permettre, aux petits etats insulaires notamment, de mieux profiter des migrations des grands poissons pelagiques dans leurs eaux.

Droits : Ifremer
http://archimer.ifremer.fr/doc/00042/15279/12665.pdf
http://archimer.ifremer.fr/doc/00042/15279/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : Abidjan is the biggest fishing harbour of tropical tunas in the Gulf of Guinea (around 100 000 mt per year). Three canneries work on four species (yellowfin, skipjack, bigeye and albacore). Small size tuna, minor tuna and by-catches are refused by the canneries and are sold on the local market fish. It is the only part of the industrial purse seine catches directly sold in Abidjan. Since 1990, fishing operations on schools of tuna associated with artificial drifting FADs has become widespread. Log fishery allow to catch a majority of small tunas, and generates by-catches of various other pelagic species associated to the logs. The landed amounts of local market fish have increased: from 8 500 Mt per year estimated between 1987 and 1990, 21 000 Mt is reached between 1991 and 1993. Since 1994, controls have been carried out by French fishing companies. A sampling scheme allows us to analyse precisely the landings since 1998. From an interdisciplinary approach, we study the socio-economic role of this local fish market, especially the links between the different actors on this market, and we analyse his impact on fishing strategies by identifying the distribution networks (actors, prices, profit) and estimating the turnovers connected to this sector.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15318/12642.pdf
http://archimer.ifremer.fr/doc/00042/15318/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : In recent years, the use of fads in Martinique has evolved from an experimental stage to a productive one. This transformation results in the pitching up of operational device park by the regional fishery committee. Nevertheless, this technical change in fishing practices is not implemented in a homogeneous way all around the island; some differences exist especially between the Atlantic and the Caribbean coasts. From surveys carried out during an annual cycle on two main landing sites, this study describes the pelagic fishing activity around fads and in the open sea. A comparison of fishing strategies adopted in different places as well as an analysis of the results obtained by the fishing units in terms of species (size of catches and daily yields) allow to describe the progress made in the implementation adoption of this new fishing practice. For several fishermen, fishing around fads has become an exclusive job, practised all year round. For others, fads is used in addition to traditional fishing activity on flotsam, "Miquelon" fishing and keeps a seasonal character.Original Abstract: Au cours des recentes annees, l'utilisation des DCP en Martinique est passee du stade experimental au stade operationnel. Cette mutation se traduit par la prise en charge du parc de dispositifs operationnels par le comite regional des peches. Toutefois, l'adoption de cette nouvelle technique d'exploitation ne s'effectue pas de facon homogene dans toutes les communes de l'ile, des differences existent notamment entre les cotes Atlantique et Caraibe. A partir d'enquetes effectuees pendant un cycle annuel, sur deux principaux points de debarquement, cette etude decrit l'activite de peche des poissons pelagiques avec ou sans DCP. Une comparaison des strategies de peche developpees dans les differents sites ainsi qu'une analyse des resultats obtenus par les unites de peche en termes d'especes, de taille des captures, de rendement journalier permettent de decrire la progression differenciee de l'adoption de cette nouvelle activite halieutique. Pour certains pecheurs, la peche sous DCP est devenue un metier exclusif, pratique tout au long de l'annee. Pour d'autres, le DCP est utilise en complement de l'activite traditionnelle de peche sous bois derivants, " peche a Miquelon ", et conserve un caractere saisonnier.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15298/12657.pdf
http://archimer.ifremer.fr/doc/00042/15298/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : Hawaii was one of the first locations to adapt the Philippine payao concept for use in high energy, deep-water environments. Initial experimental fad deployments were made by the National Marine Fisheries Service in 1977. In 1980, the State of Hawaii started deploying FADs in a programme that has since expanded to its current status of 52 approved surface fad sites. Funding is primarily derived from federal US programmes and the FADs are primarily focused on the sport fishing community. fad sites were selected to expedite access by sport fishermen; specific sites were chosen after consultation with fishermen at public hearings. Since 1997, the FAD system has been managed on a collaborative basis between the State of Hawaii and the University of Hawaii. Hawaiian FADs evolved through two previous designs before the current system of single-sphere spar-buoy was adopted. Today's FADs have an "inverse catenary" mooring system comprised of sections of floating and sinking rope attached to a "tripod" concrete block anchor system. fad sites range between 3.2 km and 46 km from shore. Mooring depths range between 200 and 3,000 metres. Average on-site longevity is 31 months; there is no correlation between longevity and depth of mooring. Windward locations have significantly shorter lifespans than leeward locations. Ten to twenty fads are replaced each year. Each FAD costs approximately us$ 7,500 to build and deploy. Hawaiian fads are heavily used by private and commercial sport fishermen and by small-scale artisanal and commercial fishermen. Commercial pole-and-line boats occasionally use the FADs to capture skipjack tuna. Hawaiian FADs will continue to be used for various types of pelagic fisheries research.

Droits : Ifremer
http://archimer.ifremer.fr/doc/00042/15280/12666.pdf
http://archimer.ifremer.fr/doc/00042/15280/

Éditeur(s) : Wiley-blackwell
Résumé : 1. Approximately 300 pelagic fish species naturally aggregate around floating objects (FOBs) at the surface of the oceans. Currently, more than 50% of the world catch of tropical tuna comes from the industrial tuna fisheries around drifting FOBs. Greater understanding of the complex decision-making processes leading to this aggregation pattern and the impact of the massive release of artificial FOBs by fishermen on the spatial distribution and management of tuna is needed. 2. We analyse how the interplay between social (relationships between individuals) and non-social (responses to the environment) behaviours may affect the spatial distribution of a population in a multi-FOB environment. Taking the example of tropical tunas associating with FOBs and using differential equations and stochastic simulations, we examine how, when increasing the number of FOBs, fish aggregation dynamics and the distribution of the population among patches are affected by the population size, level of sociality and the natural retentive and/or attractive forces of FOBs on individual tuna. 3. Our model predicts that, depending on the species' level of sociality, fish will be scattered among FOBs or aggregated around a single FOB based on the number of FOBs deployed in a homogeneous oceanic region. 4. For social species, we demonstrated that the total fish catch is reduced with increasing FOBs number. Indeed, for each size of population, there are a number of FOBs minimizing the total population of fish associated with FOBs and another number of FOBs maximizing the total population of associated fish. 5. Synthesis and applications. In terms of fisheries management, the total catch volume is directly linked to the total number of floating objects (FOBs) for non-social species, and any limit on the number of sets would then result in a limit on the total catch. For social species (e.g. tuna), however, increasing the number of FOBs does not necessarily lead to an increase in the total catch, which is a non-intuitive result. Indeed, our model shows that, for specific values of the parameters, deploying a greater number of FOBs in the water (all other parameters being constant) does not necessarily help fishermen to catch more tuna, but does increase the level of fishing effort and bycatch.
Journal Of Applied Ecology (0021-8901) (Wiley-blackwell), 2013-10 , Vol. 50 , N. 5 , P. 1081-1092

Droits : 2013 The Authors. Journal of Applied Ecology, 2013 British Ecological Society
http://archimer.ifremer.fr/doc/00151/26275/24439.pdf
DOI:10.1111/1365-2664.12140
http://archimer.ifremer.fr/doc/00151/26275/

Éditeur(s) : Pergamon-elsevier Science Ltd
Résumé : Catch data of large pelagic fish such as tuna, swordfish and billfish are highly variable ranging from short to long term. Based on fisheries data, these time series are noisy and reflect mixed information on exploitation (targeting, strategy, fishing power), population dynamics (recruitment, growth, mortality, migration, etc.), and environmental forcing (local conditions or dominant climate patterns). In this work, we investigated patterns of variation of large pelagic fish (i.e. yellowfin tuna, bigeye tuna, swordfish and blue marlin) in Japanese longliners catch data from 1960 to 2004. We performed wavelet analyses on the yearly time series of each fish species in each biogeographic province of the tropical Indian and Atlantic Oceans. In addition, we carried out cross-wavelet analyses between these biological time series and a large-scale climatic index, i.e. the Southern Oscillation Index (Sol). Results showed that the biogeographic province was the most important factor structuring the patterns of variability of Japanese catch time series. Relationships between the SOI and the fish catches in the Indian and Atlantic Oceans also pointed out the role of climatic variability for structuring patterns of variation of catch time series. This work finally confirmed that Japanese longline CPUE data poorly reflect the underlying population dynamics of tunas. (C) 2010 Elsevier Ltd. All rights reserved.
Progress In Oceanography (0079-6611) (Pergamon-elsevier Science Ltd), 2010-07 , Vol. 86 , N. 1-2 , P. 276-282

Droits : 2010 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/00011/12231/9029.pdf
DOI:10.1016/j.pocean.2010.04.019
http://archimer.ifremer.fr/doc/00011/12231/