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Registros recuperados: 105 | |
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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... |
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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... |
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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... |
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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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Lehuta, Sigrid; Petitgas, Pierre; Mahevas, Stephanie; Huret, Martin; Vermard, Youen; Uriarte, Andres; Record, Nicholas R.. |
Assessing the validity of a model is essential for its credibility especially when the model is used as decision making tool. Complex dynamic fishery models are recommended to investigate the functioning of fisheries and to assess the impact of management strategies, particularly spatial fishing regulations. However, their use is limited due to the difficulty and computational cost of parameterizing and gaining confidence, particularly for parameter rich models. These difficulties are compounded by uncertainty regarding parameter values, many of which are often taken from literature or estimated indirectly. Here we propose a methodology to improve confidence and understanding in the model, easily transferable to any complex model. The approach combines... |
Tipo: Text |
Palavras-chave: Bay of Biscay anchovy; Dynamic fishery model; Model selection; Uncertainty; Validation. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00148/25965/24150.pdf |
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Hufnagl, Marc; Payne, Mark; Lacroix, Genevieve; Bolle, Loes J.; Daewele, Ute; Dickey-collas, Mark; Gerkema, Theo; Huret, Martin; Janssen, Frank; Kreus, Markus; Paetsch, Johannes; Pohlmann, Thomas; Ruardij, Piet; Schrum, Corinna; Skogen, Morten D.; Tiessen, Meinard C. H.; Petitgas, Pierre; Van Beek, Jan K. L.; Van Der Veer, Henk W.; Callies, Ulrich. |
Hydrodynamic Ocean Circulation Models and Lagrangian particle tracking models are valuable tools e.g. in coastal ecology to identify the connectivity between offshore spawning and coastal nursery areas of commercially important fish, for risk assessment and more for defining or evaluating marine protected areas. Most studies are based on only one model and do not provide levels of uncertainty. Here this uncertainty was addressed by applying a suite of 11 North Sea models to test what variability can be expected concerning connectivity. Different notional test cases were calculated related to three important and well-studied North Sea fish species: herring (Clupea harengus), and the flatfishes sole (Solea solea) and plaice (Pleuronectes platessa). For sole... |
Tipo: Text |
Palavras-chave: Ocean circulation; Lagrangian approach; Variability; Marine protected areas; Renewable energy; Wind park; Model intercomparison; Ensemble. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00385/49660/50198.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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Huret, Martin; Petitgas, Pierre; Struski, Caroline. |
Fish populations show complex life cycles with successive dependent life stages, the spatio-temporal patterns of distribution at one stage impacting distribution, growth and mortality during the next stage. Here we propose to assess the relative effect of spawning (timing, duration, fecundity and spatial distribution, resulting from adult environmental conditions over autumn and winter) and larval mortality on the resulting survival at the age of metamorphosis. We used a suite of models run sequentially : a coupled physical-biogeochemical model to provide the environmental forcing, a Dynamic Energy Budget (DEB) model for adult fish growth and reproduction (spawning timing, duration and fecundity), an Individual Based Model (IBM) for larval drift, growth... |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00023/13451/10464.pdf |
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Lassalle, G.; Lobry, J.; Le Loc'H, F.; Bustamante, Paco; Certain, Gregoire; Delmas, Daniel; Dupuy, C.; Hily, Christian; Labry, Claire; Le Pape, O.; Marquis, Elise; Petitgas, Pierre; Pusineri, Claire; Ridoux, Vincent; Spitz, J.; Niquil, Nathalie. |
The Bay of Biscay (North-East Atlantic) has long been subjected to intense direct and indirect human activities that lead to the excessive degradation and sometimes overexploitation of natural resources. Fisheries management is gradually moving away from single-species assessments to more holistic, multi-species approaches that better respond to the reality of ecosystem processes. Quantitative modelling methods such as Ecopath with Ecosim can be useful tools for planning, implementing and evaluating ecosystem-based fisheries management strategies. The aim of this study was therefore to model the energy fluxes within the food web of this highly pressured ecosystem and to extract practical information required in the diagnosis of ecosystem state/health. A... |
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Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00057/16851/14329.pdf |
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Petitgas, Pierre; Magri Hoeltzener, Stephanie; Lazure, Pascal. |
Modelling the vertical distribution of fish eggs is important when assessing fish stocks with egg production methods and for monitoring the reproductive potential of fish populations. Fish eggs are passive particles and their vertical distribution is determined by a few parameters such as egg density, egg diameter, wind- and tide-induced turbulence, and vertical hydrographic structure. A one-dimensional vertical biophysical, numerical model was developed which was adapted to the hydrography of shelf seas under the influence of tidal currents, wind-induced circulation, and river discharges. The biological part of the model parameterized the ascent velocity of the egg as a function of egg properties (diameter, density) and water properties (density,... |
Tipo: Text |
Palavras-chave: Vertical distribution; Sprat; Sardine; Fish egg buoyancy; CUFES; Biophysical coupling; Anchovy. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2277.pdf |
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Petitgas, Pierre; Secor, Dave H.; Mcquinn, Ian; Huse, Geir; Lo, Nancy. |
Experience has established that the recovery of many collapsed stocks takes much longer than predicted by traditional fishery population models. We put forward the hypothesis that stock collapse is associated with disruption of the biological mechanisms that sustain life-cycle closure of intrapopulation contingents. Based on a review of case studies of nine marine fish stocks, we argue that stock collapses not only involve biomass loss, but also the loss of structural elements related to life-cycle diversity (contingents), as well as the breakdown of socially transmitted traditions (through a curtailed age range). Behavioural mechanisms associated with these structural elements could facilitate recovery of depleted populations. Migratory behaviour is... |
Tipo: Text |
Palavras-chave: Behaviour; Collapse; Life-cycle diversity; Recovery. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00021/13186/10262.pdf |
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Petitgas, Pierre; Rijnsdorp, Adriaan D.; Dickey-collas, Mark; Engelhard, Georg H.; Peck, Myron A.; Pinnegar, John; Drinkwater, Kenneth F.; Huret, Martin; Nash, Richard. |
To anticipate the response of fish populations to climate change, we developed a framework that integrates requirements in all life stages to assess impacts across the entire life cycle. The framework was applied on plaice (Pleuronectes platessa) and Atlantic herring (Clupea harengus) in the North Sea, Atlantic cod (Gadus morhua) in the Norwegian/Barents Seas and European anchovy (Engraulis encrasicolus) in the Bay of Biscay. In each case study, we reviewed habitats required by each life stage, habitat availability, and connectivity between habitats. We then explored how these could be altered by climate change. We documented environmental processes impacting habitat availability and connectivity, providing an integrated view at the population level and in... |
Tipo: Text |
Palavras-chave: Connectivity; Habitat; Eco-physiology; Anchovy; Herring; Plaice; Cod. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00118/22935/20798.pdf |
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Registros recuperados: 105 | |
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