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| Registros recuperados: 61 | |
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| Doray, Mathieu; Badts, Vincent; Masse, Jacques; Duhamel, Erwan; Huret, Martin; Doremus, Ghislain; Petitgas, Pierre. |
| The PELGAS sea cruises aim at monitoring the Bay of Biscay pelagic ecosystem, in order to provide scientific data for the implementing of an ecosystemic management of Biscay living ressources. The spatial and temporal dynamics of small pelagic fish populations are specifically monitored, with a focus on anchovy populations. The cruise hence takes place in spring, during anchovy spawning, to allow for the assessment of both eggs and adult stages. The PELGAS ecosystemic cruise aims at collecting data at each level of the Biscay trophic chain. Data are collected continuously along parallel transects covering the whole Bay of Biscay, in order to thoroughly characterize the horizontal and vertical structures of the pelagic ecosystem. Multibeam and... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00191/30259/28714.pdf |
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| Doray, Mathieu; Angelico, Maria Manuel; Iglesias, Magdalena; Jimenez, Paz; Marques, Vitor; Ramos, Fernando; Rodriguez-climent, Silvia; Santos, Maria; Van Der Kooij, Jeroen; Petitgas, Pierre. |
| The Working Group on Acoustic and Egg Surveys (WGACEGG) coordinates the pelagic integrated surveys in ICES Areas 7, 8 and 9. Those surveys provide fisheries-independent, acoustic and/or egg-based estimates of the biomass and demographic structure of sardine and anchovy populations. Survey biomass estimates are the main inputs used to manage those commercially important small pelagic stocks in the European Atlantic area (EAA). Taking advantage of the fine spatial resolution of acoustic and egg data, and of ancillary ecosystem data provided by integrated pelagic surveys, WGACEGG also compile standard gridded maps of anchovy and sardine eggs and adult biomass, as well as maps of key in-situ hydrological parameters (surface salinity and temperature). We... |
| Tipo: Text |
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| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00457/56841/58650.pdf |
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| Doray, Mathieu; Petitgas, Pierre; Romagnan, Jean-baptiste; Huret, Martin; Duhamel, Erwan; Dupuy, Christine; Spitz, Jérôme; Authier, Matthieu; Berger, Laurent; Doremus, Ghislain; Bourriau, Paul; Grellier, Patrick; Masse, Jacques; Sanchez, Florence. |
| The initial focus of the PELGAS integrated survey was to assess the small pelagic fish biomass in the Bay of Biscay in springtime, for fisheries management purposes. Sampling has been extended to produce long-term time-series of spatially-explicit data and indices, describing the main pelagic ecosystem components: hydrology, phytoplankton, mesozooplankton, fish and megafauna. A collaborative analysis of these datasets has brought new insights on the Bay of Biscay pelagic ecosystem summarized here. New results on single ecosystem components include an analysis of water samples to groundtruth the results of an ocean color algorithm aiming at detecting phytoplanktonic coccolithophores. New insights on mesozooplankton spatio-temporal distribution and energy... |
| Tipo: Text |
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| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00445/55665/57331.pdf |
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| Petitgas, Pierre; Huret, Martin; Doray, Mathieu; Bourriau, Paul; Lunven, Michel. |
| Since 2000, the yearly acoustic pelagic survey of Ifremer in the Bay of Biscay designed for fish stock assessment of small pelagic fish has been converted into an integrated pelagic ecosystem monitoring plateforme. This has been achieved by coupling sensors and automating data acquisition streams. The data series now spans from 2000 to 2014. Together with data sensors and sampling designs, we present here an integrated study allowing to understand the spawning process of anchovy. We compare the maps of anchovy eggs obtained with CUFES (continuous underway fish egg sampler) with that of their spawning adults sampled at the same time by acoustics and identification trawl hauls. The distributions of eggs are surprisingly different than that of adults, with in... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00281/39177/37738.pdf |
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| Doray, Mathieu; Petitgas, Pierre; Huret, Martin; Duhamel, Erwan; Romagnan, Jean-baptiste; Authier, Matthieu; Dupuy, Christine; Spitz, Jerome. |
| This paper is a practical contribution to two important debates raised by the implementation of marine ecosystem based management: (i) which ecosystem data can be provided by a fisheries survey optimised for ecosystem monitoring; and (ii) how to combine/select potential indicators to derive useful information on marine ecosystem status and dynamics? A suite of 143 potential indicators, including spatial indices, representing small pelagic fish and their biotic and abiotic environments are presented. Indicators were routinely derived from the PELGAS integrated ecosystem survey conducted in spring in the Bay of Biscay (BoB). The general patterns over time in this suite of 5–16 years, non-stationary time series are characterised using a methodology based on... |
| Tipo: Text |
Palavras-chave: Min/max autocorrelation factors; Time correlation; Survey-based indicators; Marine Strategy Framework Directive; Ecosystem variability; Bay of Biscay; Pelagic ecosystem. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00414/52552/53443.pdf |
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| Cresson, Pierre; Chouvelon, Tiphaine; Bustamante, Paco; Bănaru, Daniela; Baudrier, Jerome; Le Loch, Francois; Mauffret, Aourell; Mialet, Benoit; Spitz, Jérome; Wessel, Nathalie; Briand, Marine; Denamiel, Margaux; Doray, Mathieu; Guillou, Gaël; Jadaud, Angelique; Lazard, Coline; Noûs, Camille; Prieur, Solène; Rouquette, Manuel; Saraux, Claire; Serre, Sandrine; Timmerman, Charles-andre; Verin, Yves; Harmelin-vivien, Mireille. |
| Investigating the drivers of fish assemblage trophic structure is a critical question, in order to better understand ecosystem functioning, predict the effects of perturbations and implement integrated management of exploited marine ecosystems. Ecosystemic surveys enabled the determination of the trophic structure of the fish assemblages in three French marine ecosystems, namely the Eastern English Channel, the Bay of Biscay and the Gulf of Lions, through the simultaneous collection of qualitative (stable isotopes and energy content) and quantitative (biomass) data. In the Bay of Biscay and in the Gulf of Lions, pelagic primary production supported at least 80% of the fish biomass production, and explained the dominance of pelagic species, but with... |
| Tipo: Text |
Palavras-chave: Fish community; Trophodynamics; Food webs; Benthic-pelagic coupling. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00629/74120/73562.pdf |
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| Trenkel, Verena; Berger, Laurent; Bourguignon, Sebastien; Doray, Mathieu; Fablet, Ronan; Masse, Jacques; Mazauric, Valerie; Poncelet, Cyrille; Quemener, Gael; Scalabrin, Carla; Villalobos, Hector. |
| 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... |
| Tipo: Text |
Palavras-chave: Multibeam echosounder; Oceanographic AUV; Pelagic fish; Fisheries acoustics. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11165/7517.pdf |
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| Huse, G.; Mackenzie, B. R.; Trenkel, Verena; Doray, Mathieu; Nottestad, L.; Oskarsson, G.. |
| The North Atlantic is a productive marine region which has supported important commercial fisheries for centuries. Many of these fisheries have exploited the pelagic species, including herring, blue whiting and tuna. Here we present data on the distribution of herring and blue whiting based on the international ecosystem survey in the Nordic Seas (IESNS), the bottom trawl survey in the Bay of Biscay and Celtic Sea (EVHOE) and the pelagic survey in the Bay of Biscay (PELGAS). We also present catch data on bluefin tuna, which has been depleted for decades but historically used to be a key predator on the other pelagic stocks during summer. The results show that there were substantial changes in the herring and blue whiting distribution during the 1990s and... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00276/38675/37150.pdf |
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| Duhamel, Erwan; Doray, Mathieu; Huret, Martin; Sanchez, Florence; Lespagnol, Patrick; Doremus, Ghislain; Lemerre, Charlotte. |
| The Pelgas16 acoustic survey has been carried out with very good weather conditions (regular low wind, medium temperatures) for the whole area, from the South of the bay of Biscay to the west of Brittany. The help of commercial vessels (two pairs of pelagic trawlers and a single one) during 18 days provided about 120 valid identification hauls instead of about 60 before 2007 when Thalassa was alone to identify echotraces. Their participation increased the precision of identification of echoes and some double hauls permitted to confirm that results provided by the two types of vessels (R/V and Fishing boats) were comparable and usable for biomass estimate purposes. These commercial vessels participated to the PELGAS survey in a very good spirit of... |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00344/45546/45157.pdf |
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| Doray, Mathieu; Stequert, Bernard; Taquet, Marc. |
| Daily growth increments measured in the otolith of Thunnus atlanticus were used to estimate the age and growth of individuals. which were sampled from an artisanal fishery operating around fish aggregating devices (FADs) moored off Martinique Island. In this study, 76 otoliths were analysed for fish ranging from 20 to 68 cm fork lengths (FL). The fish were caught using trolling lines at depths ranging from 0 to 10 m. Counts were made, under a light microscope, on the external part of the transverse section of the sagittae, from the primordium to the ventral edge. The mean coefficient of variation of the age reading was 2.4%. To validate readings, the number of increments for 11 individuals was counted using both optic and scanning electron microscopes. The... |
| Tipo: Text |
Palavras-chave: Thunnus atlanticus; Daily increment; Otolith; Age. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-396.pdf |
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| Petitgas, Pierre; Grellier, Patrick; Duhamel, Erwan; Masse, Jacques; Doray, Mathieu. |
| Individual fish growth depends on internal population factors such as phenotypic variability as well as external factors such as past environmental conditions (temperature, food) and selective mortality (predation or fishing). In the anchovy, growth in the first year is key to population dynamics as it determines the potential energy allocated to reproduction as well as the capacity to occupy off-shore habitats. Further, in the recent past, the anchovy in the bay of Biscay has experienced collapse and recovery and the role played by growth in this history is unknown. Since 2001 with the spring acoustic survey series PelGas, we have monitored individual fish growth by measuring in the otolith the increments between annual rings, in addition to age... |
| Tipo: Text |
Palavras-chave: Anchovy; Biscay; Otoliths; Growth; Metapopulation. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00114/22550/20236.pdf |
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| Doray, Mathieu; Huret, Martin; Couturier, Christian; Doublet, Sylvain. |
| L'objectif des Nation Unies pour le développement durable de l’Océan (ODD14) peut il se décliner dans le secteur de la pêche en France ? Et si oui comment ? La principale fonction de la pêche (et de l’aquaculture) françaises étant la fourniture de produits de la mer à des fins alimentaires, nous replaçons la pêche (et de l’aquaculture) françaises dans le contexte plus large de l’approvisionnement alimentaire du pays. Nous présentons le scénario prospectif Afterres2050, qui propose une trajectoire vers un approvisionnement alimentaire durable pour le France (et quelques voisins) en 2050. Afterres2050 est un scénario technique qui vise à satisfaire nos besoins, en alimentation, en énergie, et en matériaux à l’horizon 2050, dans le respect des écosystèmes,... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00512/62325/66583.pdf |
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| Doray, Mathieu; Petitgas, Pierre; Masse, Jacques. |
| Estimer la biomasse d'un stock de poissons par acoustique nécessite de combiner des données de nature diverse collectées le long du parcours d'échantillonnage (Woillez et al., 2009). Il s'agit essentiellement de combiner trois champs de données spatialisées : une carte de densités acoustiques attribuées aux poissons, une carte de proportions d'espèces et une carte de longueurs moyennes. |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00003/11447/7997.pdf |
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| Doray, Mathieu; Petitgas, Pierre; Josse, E. |
| Universal kriging was used to model the spatio-temporal variability in the acoustic density of tuna aggregations recorded during star echosounding surveys around moored fish aggregating devices (FADs) in Martinique (Lesser Antilles). The large-scale deterministic drift in the tuna spatial distribution was modeled using an advection-diffusion equation applied to animal grouping. Residuals from the drift were modeled as a random component with small-scale spatial correlation. An estimation variance formula was derived from this deterministic-statistical mixed model to assess the mean precision of density estimates of daytime tuna aggregation. The mean relative error obtained with our star design for daytime surveys was 24%. The methodology was applied to... |
| Tipo: Text |
Palavras-chave: Acoustic survey precision; Advection diffusion model; Moored fish aggregating devices; Tuna; Geostatistics. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4559.pdf |
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| Registros recuperados: 61 | |
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