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| Registros recuperados: 26 | |
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| Bertignac, Michel; Auby, Isabelle; Sauriau, Pierre-guy; De Montaudouin, Xavier; Foucard, Julie; Martin, Sophie. |
| As part of a larger project financed by the European Union programme "Community initiative PESCA" on the study of "small scale fisheries" in Aquitaine (France), an estimation of the stock of clams in the Bassin d'Arcachon has been conducted. A two-stage stratified random sampling survey has been designed. Samples have been collected using a Hamon bottom sampler in 237 locations distributed over 24 km2. The clam Tapes philippinarum, which appeared in the basin following a series of aquaculture experiments in the mid eighties, is now the main species accounting for more than 90% of the abundance and the biomass, largely overcoming the European species Tapes decussata. The mean abundance and biomass (26 clams / m2 et l28g / m2) are above those estimated in... |
| Tipo: Text |
Palavras-chave: Palourde; Tapes philippinarum; Tapes decussata; Evaluation stock; Pêche; Pêche à pied; Echantillonnage; Bassin d'Arcachon; Clam; Tapes philippinarum; Tapes decussata; Stock assessment; Fishery; Sampling; Bassin d'Arcachon. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00105/21658/19240.pdf |
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| Macher, Claire; Bailly, Denis; Ballesteros, Marta; Bertignac, Michel; Collocas, Francesco; Fitzpatrick, Mike; Frangoudes, Katia; Garcia, Dorleta; Kraan, Marloes; Little, Rich; Mardle, Simon; Murillas, Arantza; Pawlowski, Lionel; Philippe, Manuelle; Prellezo, Raul; Sabatella, Evelina; Steins, Nathalie; Thebaud, Olivier; Ulrich, Clara. |
| Implementation of Ecosystem Based Management in fisheries has led to higher integration of knowledge in advices and higher engagement of stakeholders in the decision support Process. As part of the process, fisheries scientists contribute in different ways and at different levels to decision support and experienced partnership approaches in the context of research projects or institutional decision support. Role of scientists in the process is however not trivial to define and operationalize. Several pitfalls can occur that scientists may have experienced through partnership projects or in the expert assessments done for authorities. A workshop was organized from 15 to 17 January 2018 as part of the ScipaDe ... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00463/57452/59561.pdf |
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| Véron, Matthieu; Duhamel, Erwan; Bertignac, Michel; Pawlowski, Lionel; Huret, Martin; Baulier, Loic. |
| Age and size at maturation appear as key parameters governing the dynamics of a population as they affect growth rate, fecundity, and survival. The expression of such life history traits is determined by genetic make-up and modulated by environmental factors mainly through phenotypic plasticity. Moreover, fishing, besides decreasing population size and changing demographic composition can alter allelic frequencies through fisheries-induced evolution by selecting for some particular traits. In the Bay of Biscay, a decreasing trend in both sardine body condition and size-at-age has recently been pointed out at the population level. The Probabilistic Maturation Reaction Norm (PMRN) approach was applied to help disentangle phenotypic plasticity and genetic... |
| Tipo: Text |
Palavras-chave: Fisheries-induced evolution; Body condition; Phenotypic plasticity; Maturation; Growth; Sardina pilchardus; Bay of biscay. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00660/77203/78637.pdf |
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| Biseau, Alain; Bellail, Robert; Bertignac, Michel; Biais, Gerard; Bigot, Jean-louis; Bouche, Ludovic; Bourjea, Jerome; Caro, Anthony; De Casamajor, Marie-noelle; Caill-milly, Nathalie; Drogou, Mickael; Duhamel, Erwan; Fifas, Spyros; Foucher, Eric; Fromentin, Jean-marc; Jadaud, Angelique; Lampert, Luis; Laurans, Martial; Lissardy, Muriel; Lorance, Pascal; Mahe, Jean-claude; Mahe, Kelig; Masse, Jacques; Morandeau, Gilles; Pawlowski, Lionel; Poisson, Francois; Reynal, Lionel; Roos, David; Verin, Yves; Vermard, Youen; Vigneau, Joel. |
| Ce document présente l'état des principaux stocks exploités par les flottes françaises en termes de mortalité par pêche et de biomasse de reproducteurs. La situation fin 2010 (début 2011) par rapport aux points de référence (de précaution et Fmsy) est indiqué lorsque les indicateurs sont estimés et que les références sont définies. Les grandes tendances en matière d'évolution des mortalités et biomasses sont également indiquées. |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14656/11956.pdf |
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| Doyen, Luc; Thebaud, Olivier; Bene, Christopher; Martinet, V.; Gourguet, S.; Bertignac, Michel; Fifas, Spyros; Blanchard, Fabian. |
| Academia and management agencies show a growing interest for ecosystem-based fishery management (EBFM). However, the way to operationalize this approach remains challenging. The present paper illustrates how the concepts of stochastic co-viability, which accounts for dynamic complexities, uncertainties, risk and sustainability constraints, can be useful for the implementation of EBFM. In the present case, this concept is used to identify fishing strategies that satisfy both ecological conservation and economic sustainability in a multi-species, multi-fleet context. Economic Viability Analysis (EVA) and the broader Co-Viability Analysis (CVA), are proposed to expand the usual Population Viability Analysis (PVA) and precautionary approach. An illustration is... |
| Tipo: Text |
Palavras-chave: Ecosystem based fisheries management; Viability; Stochastic; Nephrops; Hake. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00074/18571/16153.pdf |
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| Bertignac, Michel; Moguedet, Philippe. |
| An adaptation to the cohort analysis is suggested when age catches distribution are known only on a year and when the effort datas ot previouses years, for each ot the vessels fishing the considerated stock, are availables. An example to the estimation of fish mortality coefficients and of the recruitment abundancy for the stocks of sea bass (Dicentrarchus labrax) from Morbras (ICES division VIII A) and ling (Molva molva) from west of Scotland (ICES division VI A), is given. |
| Tipo: Text |
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| Ano: 1987 |
URL: http://archimer.ifremer.fr/doc/00396/50756/51465.pdf |
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| Drouineau, Hilaire; Mahevas, Stephanie; Bertignac, Michel; Duplisea, Daniel. |
| Drouineau, H., Mahevas, S., Bertignac, M., and Duplisea, D. 2010. A length-structured spatially explicit model for estimating hake growth and migration rates. - ICES Journal of Marine Science, 67: 1697-1709. |
| Tipo: Text |
Palavras-chave: Growth; Length-structured model; Merluccius merluccius; Migration; Spatial model. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00016/12714/9767.pdf |
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| Doyen, Luc; Bene, Christophe; Bertignac, Michel; Blanchard, Fabian; Cisse, Abdoul; Dichmont, Catherine; Gourguet, Sophie; Guyader, Olivier; Hardy, Pierre-yves; Jennings, Sarah; Little, Lorne Richard; Macher, Claire; Mills, David Jonathan; Noussair, Ahmed; Pascoe, Sean; Pereau, Jean-christophe; Sanz, Nicolas; Schwarz, Anne-maree; Smith, Tony; Thebaud, Olivier. |
| Reconciling food security, economic development and biodiversity conservation is a key challenge, especially in the face of the demographic transition characterizing many countries in the world. Fisheries and marine ecosystems constitute a difficult application of this bio-economic challenge. Many experts and scientists advocate an ecosystem approach to manage marine socio-ecosystems for their sustainability and resilience. However, the ways by which to operationalize ecosystem-based fisheries management (EBFM) remain poorly specified. We propose a specific methodological framework-viability modelling-to do so. We show how viability modelling can be applied using four contrasted case-studies: two small-scale fisheries in South America and Pacific and two... |
| Tipo: Text |
Palavras-chave: Biodiversity; Ecological economics; Ecosystem approach; Fisheries; Scenario; Viability. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00409/52009/52724.pdf |
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| Raveau, Adriana; Macher, Claire; Mehault, Sonia; Merzereaud, Mathieu; Le Grand, Christelle; Guyader, Olivier; Bertignac, Michel; Fifas, Spyros; Guillen Garcia, Jordi. |
| Several fleets with various fishing strategies operate as a mixed fishery in the Bay of Biscay. Among the main fleets, bottom trawlers target Norway lobster (Nephrops norvegicus) and, together with gillnetters, they also catch hake (Merluccius merluccius). Trawling leads to average-size catches that are below the minimum landing size (MLS); such catches are discarded since they cannot be sold. These discards result in negative impacts on stock renewal, as most of them do not survive. This also results in an economic loss for both bottom trawlers and gillnetters since these discards represent a future loss of rent. This study, based on the 2009 and 2010 selectivity experiments at sea, assesses the short- and long-term bio-economic impacts of four... |
| Tipo: Text |
Palavras-chave: Demersal trawl fishery; Bio-economic analysis; Selectivity; Simulation; Selective device; Nephrops norvegicus; Merluccius merluccius; Atlantic Ocean. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00110/22135/19774.pdf |
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| Le Floc'H, Pascal; Bertignac, Michel; Curtil, Olivier; Macher, Claire; Mariat-roy, Emilie; Paulet, Yves-marie. |
| This study considers how to reconcile different spatial scales to find the best common denominator to be used as an ecosystem-based management unit. For this, two fishery production zones differing ecologically, economically, legally and institutionally were investigated. The first case study is located within French territorial waters, in a MPA created in 2007- the Parc Naturel Marin d'Iroise (PNMI). The second case study, the Bay of Biscay, covers both territorial waters and the French exclusive economic zone. The paper adopts a multidisciplinary approach. Relevant questions concern how marine space is shared between exploited species and fishing fleets, especially the spatial mobility strategies they employ. An assessment of the institutional system... |
| Tipo: Text |
Palavras-chave: Spatial scale; Ecosystem-based fisheries management; Marine protected area; Socio-system. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00460/57191/59156.pdf |
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| Veron, Matthieu; Lebigre, Christophe; Bertignac, Michel; Doray, Mathieu; Duhamel, Erwan; Huret, Martin; Pawlowski, Lionel. |
| Peu de modèles d'évaluation de stock intègrent une description fine des processus biologiques régissant les populations exploitées par la pêche au sein des écosystèmes. Ce manque est particulièrement regrettable dans le cas des petits pélagiques dont la dynamique est fortement influencée par les conditions environnementales. En effet, la pêche et les fluctuations environnementales et climatiques impactent fortement la dynamique de population de la sardine du golfe de Gascogne. Pour comprendre la dynamique de cette population au sein de l'écosystème et les effets des pêcheries, il est donc nécessaire d'identifier et de caractériser cet ensemble de pressions. Afin d'améliorer la gestion et le suivi de la dynamique de ce stock, le développement d'un modèle... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00410/52133/52842.pdf |
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| Macher, Claire; Bertignac, Michel; Guyader, Olivier; Frangoudes, Katia; Fresard, Marjolaine; Le Grand, Christelle; Merzereaud, Mathieu; Thebaud, Olivier. |
| In the context of the Common Fisheries Policy Reform, the implementation of multiannual management plans for fisheries and the annual quota negotiations between EU member states has generated a growing demand from stakeholders and managers for integrated advice that goes beyond the usual biological advice. This has led to the emergence of bio-economic tools and methods for the comparison of the biological, economic and social tradeoffs associated with alternative options for fisheries management. A Decision Support Framework (DSF) has been developed in this context, with the objective to tackle technical and methodological challenges to be able to provide bio-economic advices to support decision at national and European level. It is based on a partnership... |
| Tipo: Text |
Palavras-chave: Participatory approach; Stakeholder engagement; Decision-support; Bio-economic modelling; Fisheries management; Impact assessment. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00445/55698/57395.pdf |
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| Bertignac, Michel; Fernandez, Carmen; Methot, Richard. |
| European hake (Merluccius merluccius) is widely distributed over the north-east Atlantic shelf, from Norway to Mauritania. Despite its large distribution (covering ICES Division IIIa, Subareas IV, VI and VII and Divisions VIIIa,b,d, from Norway to the Bay of Biscay) and a complex population structure, the so-called northern stock of hake is currently assessed as a single unit, using a spatially aggregated implementation of the Stock Synthesis assessment model. In this study, a preliminary spatially explicit implementation of Stock Synthesis is developed, which accounts for the distribution of the hake population during its life cycle (nurseries and spawning areas) and the distribution of the fleets (trawlers, gillnetters and long-liners) exploiting the... |
| Tipo: Text |
Palavras-chave: Northern hake; Spatial dynamics; Population structure; Spatial stock assessment.. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00126/23764/21657.pdf |
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| Ortiz De Zarate, Victoria; Bertignac, Michel. |
| In this study, an attempt is made to estimate natural mortality rate for North Atlantic albacore. We implement a spatially aggregated tag-attrition model to analyse the results of an albacore tagging experiment conducted in the Bay of Biscay from 1988 to 1991. The model predicts probabilities of the possible fates of tagged fish and the tags that they carry. The model includes several parameters consisting of catchabilities by fleets involved in recaptures and a combination of natural mortality plus emigration from the study area. Model fitting is carried out by finding the maximum of a multinomial likelihood function. Effect of reporting rate values on the estimations are evaluated and several hypothesis on the pre-mixing period of the tagged fish... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Attrition rate; Model; Natural mortality estimation; Albacore. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-977.pdf |
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| Drouineau, Hilaire; Mahevas, Stephanie; Bertignac, Michel; Fertin, A. |
| Most of the traditional assessment models are age-structured. However, many biological and exploitation processes are more length-dependent than age-dependent, and the required length-age conversion of available data is often not reliable. Consequently, length-structured or age-length structured models have undergone considerable development in recent years. The growth transition matrix used to model the mean growth and growth variability of the population, is of primary importance in a length-structured matrix model. Building this growth transition matrix is not trivial and it is necessary to assess the impact that various assumptions may have to identify robust model structures. In this study, we assess the effects of (1) time and length discretisation,... |
| Tipo: Text |
Palavras-chave: Sensitivity analysis; Discrete model; Growth; Length structured model. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4301.pdf |
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| Registros recuperados: 26 | |
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