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| Registros recuperados: 105 | |
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| Woillez, Mathieu; Petitgas, Pierre; Rivoirard, Jacques; Fernandes, Paul; Hoftstede, Remment Ter; Korsbrekke, Knut; Orlowski, Andrzej; Spedicato, Maria-teresa; Politou, Chrissi-yianna. |
| Population dynamics is commonly described non-spatially using parameters of population demography and vital traits. Population spatial organisation is therefore considered implicit and its importance in the population dynamics ignored. The present study evidences on a variety of stocks correlation between population spatial distribution indices, population abundance, recruitment and mortality. Series of research fisheries monitoring surveys were considered for a range of different stocks (cod, herring, anchovy, hake, mullet) in different regions of the North East Atlantic and Mediterranean (North Sea, Barents Sea, Baltic Sea, Bay of Biscay, Tyrrhenian Sea, Ionian Sea and Aegean Sea). For each population, each age and each year, 9 spatial indices were... |
| Tipo: Text |
Palavras-chave: Spatial indices population dynamics; Meta-analysis.. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00133/24376/22388.pdf |
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| Huret, Martin; Struski, Caroline; Leger, Fabien; Petitgas, Pierre; Lazure, Pascal; Sourisseau, Marc. |
| Une simulation 'hindcast' de la dynamique physique et biogéochimique du golfe de Gascogne a été réalisée pour la période 1971-2007 à l'aide du modèle ECO-MARS3D. Ce modèle couplant physique et biogéochimie fournit une série longue de données simulées, moyennées ou intégrées sur 3 jours (température, salinité, sels nutritifs, phytoplancton, zooplancton), qui sont ensuite utilisées pour des calculs d'indices hydrologiques 2D synthétiques (indices méso-échelle : stratification, upwellings, surface tourbillonnaire ; indices biologiques : chlorophylle-a de surface, production primaire intégrée). Nous nous proposons dans ce document de présenter la configuration et les forçages utilisés pour cette simulation, et de lister les différentes variables sauvegardées... |
| Tipo: Text |
Palavras-chave: Projet FP6 RECLAIM; Halieutique; Indices hydrologiques; Hindcast; ECO MARS3D; Modélisation couplée; Golfe de Gascogne. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/rapport-5164.pdf |
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| Goarant, Anne; Petitgas, Pierre; Bourriau, Paul. |
| Knowledge of the pelagic vertical distribution of fish eggs is central for several aspects of fisheries science including fisheries recruitment and egg production studies. In modelling egg vertical distributions, variation in fish egg density is an important issue. Though variation in egg density between individual eggs has been reported, evidence for significant spatial variation in egg density is novel. The present study provides evidence that egg density of anchovy (Engraulis encrasicolus) varies spatially across spawning sites in the Bay of Biscay, depending on the regional scale variation in sea water properties due to river discharge. We measured the density of the eggs using a density gradient column at 17 stations in 2005 and 2006 as well as their... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Anchovy; Fish egg density; Density gradient column. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3007.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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| Politikos, Dimitrios; Huret, Martin; Petitgas, Pierre. |
| Adult anchovies in the Bay of Biscay perform north to south migration from late winter to early summer for spawning. However, what triggers and drives the geographic shift of the population remains unclear and poorly understood. An individual-based fish model has been implemented to explore the potential mechanisms that control anchovy's movement routes toward its spawning habitats. To achieve this goal, two fish movement behaviors – gradient detection through restricted area search and kinesis – simulated fish response to its dynamic environment. A bioenergetics model was used to represent individual growth and reproduction along the fish trajectory. The environmental forcing (food, temperature) of the model was provided by a coupled... |
| Tipo: Text |
Palavras-chave: Individual-based model; Behavioral movement; Dynamic Energy Budget; Anchovy; Bay of Biscay. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00273/38446/36868.pdf |
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| Petitgas, Pierre; Masse, Jacques; Bourriau, Paul; Beillois, Pierre; Bergeron, Jean-pierre; Delmas, Daniel; Herbland, Alain; Koueta, Noussithe; Froidefond, Jean-marie; Santos, Maria. |
| The spatial pattern in hydro-plankton and fish distributions and their relationship were analysed based on the spring 2000 fisheries acoustic survey. The importance of this survey was that it was a multi-disciplinary platform which collected an extensive set of parameters in the hydro-plankton leading to a potentially finer description of hydro-plankton conditions and fish habitats. More than 50 variables were measured on a grid of stations, in four compartments of the ecosystem: hydrology, nutrients, primary producers and meso-zooplankton. First, a joint analysis of all hydro-plankton compartments was performed using multiple factor analysis (MFA). The method was used to estimate a compromise factorial space common to all compartments in which the... |
| Tipo: Text |
Palavras-chave: Fish environment relationship; Hydro plankton; Habitats; Multiple factor analysis; Spatial pattern. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3961.pdf |
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| Blanluet, Arthur; Doray, Mathieu; Berger, Laurent; Romagnan, Jean-baptiste; Le Bouffant, Naig; Lehuta, Sigrid; Petitgas, Pierre. |
| Sound scattering layers (SSLs) are observed over a broad range of spatio-temporal scales and geographical areas. SSLs represent a large biomass, likely involved in the biological carbon pump and the structure of marine trophic webs. Yet, the taxonomic composition remains largely unknown for many SSLs. To investigate the challenges of SSL sampling, we performed a survey in a small study area in the Northern Bay of Biscay (France) by combining broadband and narrowband acoustics, net sampling, imagery and video recordings. In order to identify organisms contributing to the observed SSLs, we compared measured frequency spectra to forward predicted spectra derived from biological data. Furthermore, to assess the confidence in SSL characterization, we evaluated... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70035/67955.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; 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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| Giannoulaki, Marianna; Petitgas, Pierre; Barra, Marco; Tugores, Pilar; Vasapollo, C.; Iglesias, M.; Leonori, Iole; De Felice, Andrea; Bonanno, A.; Basilone, G.; Mazzola, Salvatore; Bigot, Jean-louis; Machias, Athanassios; Pyrounaki, Maria M.. |
| A spatial indicator—the spreading area index—is used to describe anchovy and sardine spatial distribution in relation to biomass variation and to look for ecosystem differences within the Mediterranean basin. Specifically, the variation in the spreading area index in relation to biomass was examined for different areas of the Mediterranean Sea (i.e. Aegean Sea, western Adriatic Sea, Strait of Sicily, Gulf of Lion, and Spanish Mediterranean waters). In order to capture the spatial variability of the population at different levels of fish density, acoustic survey data for the years of highest, lowest, and intermediate abundance were used. In a subsequent step standardized values of spreading area and biomass were estimated to allow comparisons. Results... |
| Tipo: Text |
Palavras-chave: Anchovy; Mediterranean Sea; Sardine; Spreading area index. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00114/22549/20245.pdf |
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| Samb, Birame; Petitgas, Pierre. |
| This study presents an application of the geostatistical one-dimensional (1D) transitive method for estimating the precision of acoustic pelagic abundance estimates in Senegal. In applying the method, the major problem encountered was how to take into account the temporal variability in the computation of the estimation variance. In acoustic surveys, echointegration is performed continuously along the ship's sailing track. For a survey design made of parallel transects, each transect can thus be considered as a sampling unit. By summing the density values along the transects to obtain biomass values per transect, the 2D estimation is simply reduced to a 1D estimation procedure. If the transects are equidistant, the geostatistical transitive method applied... |
| Tipo: Text |
Palavras-chave: Céostatistique; Variance; Acoustique; Abondance; Geostatistics; Variance; Acoustics; Abundance. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00188/29883/28348.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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| Pardo, Sophie; Hess, Philipp; Simon, Elodie; Barille, Laurent; Geslin, Emmanuelle; Cognie, Bruno; Martin-jezequel, Véronique; Sechet, Véronique; Herrenknecht, Christine; Baron, Regis; Bourseau, Patrick; Amzil, Zouher; Masse, Anthony; Vandanjon, Laurent; Dumay, Justine; Lebeau, Thierry; Turpin, Vincent; Mondeguer, Florence; Petitgas, Pierre; Trouillet, Brice; Mercier, Denis; Guillotreau, Patrice; Guineberteau, Thierry; Mahevas, Stephanie; Schoefs, Franck; Sophie Pardo; Philipp Hess; Pauline Borgniet; Laurent Barillé; Emmanuelle Geslin; Bruno Cognie; Véronique Martin-Jezequel; Véronique Sechet; Christine Herrenknecht; Régis Baron; Patrick Bourseau; Zouher Amzil; Anthony Massé; Laurent Vandanjon; Justine Dumay; Thierry Lebeau; Vincent Turpin; Florence Mondeguer; Pierre Petitgas; Brice Trouillet. |
| COSELMAR, a 4-year project financed by the Région des Pays de la Loire at 2.1 M€, officially started on the 7th January 2013. The project is coordinated by Philipp Hess (IFREMER) and Sophie Pardo (Université de Nantes-LEMNA) and falls under the Federation for Research Institut Universitaire Mer et Littoral (IUML, FR CNRS 3473)*. COSELMAR has also been approved by the Scientific Council of the MSH Ange Guépin. COSELMAR is a research project uniting 5 research units of IFREMER and 11 laboratories of the Université de Nantes, along with academic partners, and national and international industries. The aim is to achieve a better understanding of the marine and coastal ecosystems and the associated resources. The project will also provide insights into risk... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00406/51793/52550.pdf |
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| Registros recuperados: 105 | |
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