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| Registros recuperados: 96 | |
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| Rochet, Marie-joelle; Rice, Jake C.. |
| Simulation-based management strategy evaluations are increasingly developed and used for science advice in support of fisheries management, along with risk evaluation and decision analysis. These methods tackle the problem of uncertainty in fisheries systems and data by modelling uncertainty in two ways. For quantities that are difficult to measure accurately or are inherently variable, variables are replaced by probability distributions, and system dynamics are simulated by Monte Carlo simulations, drawing numbers from these distributions. For processes that are not fully understood, arrays of model formulations that might underlie the observed patterns are developed, each is assumed successively, and the results of the corresponding arrays of model... |
| Tipo: Text |
Palavras-chave: Uncertainty; Risk estimates; Monte Carlo simulation; Management strategy evaluation. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6361.pdf |
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| Depestele, Jochen; Rochet, Marie-joelle; Doremus, Ghislain; Laffargue, Pascal; Stienen, Eric Willem Maria. |
| Fishery discards subsidise the food supply of a large community of scavenging seabirds, thus significantly influencing seabird ecology. Seabird preference for certain types of discards determines the number and composition of discards available for non-avian marine scavengers. To quantify both portions of discards temporally as well as spatially, we have used a modelling framework that integrates the spatial and temporal variation in seabird distribution, seabird attraction to fishing vessels and discard distribution. The framework was applied to a case study in the Bay of Biscay, where a wide variation in discard consumption was observed across seabird foraging guilds, discard types, periods and locations. Seabirds removed about one-quarter of the Bay of... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00334/44507/44201.pdf |
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| Eymard, Sylvie; Carcouet, Elodie; Rochet, Marie-joelle; Dumay, Justine; Chopin, Christine; Genot, Claude. |
| When fatty fish are transformed into surimi, lipid oxidation takes place, decreasing the quality of the product. This study was aimed to identify the critical stages of the process in terms of the development of lipid oxidation. Horse mackerels were transformed into surimi on a pilot line and samples taken (hand-skinned fillets = minced fillets, mince, washed and refined minces, paste, surimi and washing water). Most of the lipids were removed during the process and neutral lipids were lost in higher proportion than polar lipids. As a consequence, total lipids of surimi contained more polyunsaturated fatty acids (338 19 g kg(-1)) than total lipids of the minced fillets (220 8 g kg-1). Thiobarbituric acid reactive substances (TBARS) was higher in the minced... |
| Tipo: Text |
Palavras-chave: Process; Fatty fish; Surimi; Polyunsaturated fatty acids; Lipid oxidation. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-424.pdf |
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| Bundy, Alida; Shannon, Lynne J.; Rochet, Marie-joelle; Neira, Sergio; Shin, Yunne-jai; Hill, Louize; Aydin, Kerim. |
| Marine ecosystems have been exploited for a long time, growing increasingly vulnerable to collapse and irreversible change. How do we know when an ecosystem may be in danger? A measure of the status of individual stocks is only a partial gauge of its status, and does not include changes at the broader ecosystem level, to non-commercial species or to its structure or functioning. Six ecosystem indicators measuring trends over time were collated for 19 ecosystems, corresponding to four ecological attributes: resource potential, ecosystem structure and functioning, conservation of functional biodiversity, and ecosystem stability and resistance to perturbations. We explored the use of a decision-tree approach, a definition of initial ecosystem state (impacted... |
| Tipo: Text |
Palavras-chave: Comparative approach; Decision tree; Ecosystem classification; Ecosystem indicator; Exploited marine ecosystems. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11374/12047.pdf |
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| Fauconnet, Laurence; Badts, Vincent; Biseau, Alain; Dimeet, Joel; Dintheer, Christian; Dube, Benoit; Gaudou, Olivier; Lorance, Pascal; Messannot, Cecile; Nikolic, Natacha; Peronnet, Isabelle; Reecht, Yves; Rochet, Marie-joelle; Tetard, Alain. |
| Ce document est une synthèse des informations collectées en 2010 à bord des navires de pêche professionnelle dans le cadre de l'action ObsMer. Cette action vise à observer in situ l'activité de pêche et l'ensemble de la capture, particulièrement la partie non retenue, en identifiant les espèces capturées, les tonnages par espèce et en prenant des mesures de tailles. |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00054/16490/16058.pdf |
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| Trenkel, Verena; Daures, Fabienne; Rochet, Marie-joelle; Lorance, Pascal. |
| According to portfolio theory applied to fisheries management, economic returns are stabilised by harvesting in a portfolio stocks of species whose returns are negatively correlated and for which the portfolio economic return variance is smaller than the sum of stock specific return variances. Also, variability is expected to decrease with portfolio width. Using a range of indicators, these predictions were tested for the French fishing fleets in the Bay of Biscay (Northeast Atlantic) during the period 2001–2009. For this, vessels were grouped into eight fishing fleets based on the gears used and exploited species were grouped into five functional groups. The portfolio width of fleets ranged from 1–3 functional groups, or 4–19 species. Economic fleet... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00157/26808/24916.pdf |
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| Rochet, Marie-joelle; Daures, Fabienne; Trenkel, Verena. |
| This paper introduces a semiqualitative approach to analyse the joint dynamics of fleets and stocks in a multispecies, multifleet fishery. We ask whether changes in fleets affect resource dynamics and whether trends in resource influence fleet dynamics more than external drivers do. External drivers include vessel buyback, fuel price, and fish prices, as well as environmental fluctuations. Resource status is measured by abundance and length metrics; fleet capacity is measured by total horse power, and economic metrics such as profitability and earnings are examined as well. A maximum likelihood approach is used to identify the combined metric trends with the largest support in the data. The approach is applied to the French Bay of Biscay fisheries in... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00076/18730/16336.pdf |
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| Cornou, Anne-sophie; Dimeet, Joel; Goascoz, Nicolas; Scavinner, Marion; Rochet, Marie-joelle. |
| Ce document est une synthèse des informations collectées en 2015 à bord des navires de pêche professionnelle dans le cadre de l'action ObsMer. Cette action vise à observer in situ l’activité de pêche et l'ensemble de la capture, particulièrement la partie non retenue, en identifiant les espèces capturées, les tonnages par espèce et en prenant des mesures de tailles. Ce travail s'inscrit dans le cadre d'un partenariat entre le Comite National des Pêches Maritimes et des Élevages Marins (CNPMEM), la Direction des Pêches Maritimes et de l'Aquaculture (DPMA) du Ministère de l’Écologie, du Développement Durable et de l’Énergie, et l'Ifremer. |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00353/46441/46185.pdf |
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| Bertrand, Jacques; Brind'Amour, Anik; Cochard, Marie-laure; Coppin, Franck; Leaute, Jean-pierre; Lorance, Pascal; Mahe, Jean-claude; Morin, Jocelyne; Poulard, Jean-charles; Rochet, Marie-joelle; Schlaich, Ivan; Souplet, Arnauld; Trenkel, Verena; Verin, Yves. |
| The ecosystems exploited by fishing are complex. The species which are sought after and their distribution rely on numerous processes, in time and space. The understanding of marine ecosystems requires important means and diverse information including those of professional fishing and scientific cruises. At first, scientific fishing cruises aimed to explore marine fauna and discover new halieutic resources. They were in line with the exploration cruises carried out by Prince Albert 1st of Monaco at the end of the XIXth century. However, since the beginning of the 1970s, they have been focusing on the quantification of the resources exploited by fishing. [...] After a series of "Understanding keys" aimed at helping the reader understand the methodology and... |
| Tipo: Text |
Palavras-chave: Mediterranean Sea; Bay of Biscay; English Channel; North Sea; France; Communities; Populations; Fishery science; Indicators; Bulletin; Méditerranée; Golfe de Gascogne; Manche; Mer du Nord; France; Pêche; Campagnes à la mer; Communautés; Populations; Halieutique; Indicateurs; Bulletin. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/rapport-6160.pdf |
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| Lassalle, Geraldine; Pasqual, Jean-sebastien Nelva; Boet, Philippe; Rochet, Marie-joelle; Trenkel, Verena; Niquil, Nathalie. |
| To develop and implement ecosystem-based management, it is critical to monitor foodweb components or functional groups which are robust to uncertainty in ecosystem structure and functioning yet sensitive to changes. To select such functional groups for the Bay of Biscay continental shelf, both quantitative and qualitative foodweb models were developed. First, functional groups for which predictions of directions of change following an increase in primary productivity, prey or predators, or in fishing activities were identical across alternative qualitative model structures were identified. Second, the robustness to model type was assessed by comparing qualitative predictions with quantitative Ecopath model results. The demersal fish community was... |
| Tipo: Text |
Palavras-chave: Comparative studies; Ecosystem management; Foodweb; Loop analysis; Northeast Atlantic continental shelf. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00173/28427/26852.pdf |
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| Dube, Benoit; Dimeet, Joel; Rochet, Marie-joelle; Tetard, Alain; Gaudou, Olivier; Messannot, Cecile; Fauconnet, Laurence; Morizur, Yvon; Biseau, Alain; Salaun, Michele. |
| Ce document est une synthèse des informations collectées en 2011 à bord des navires de pêche professionnelle dans le cadre de l'action ObsMer. Cette action vise à observer in situ l'activité de pêche et l'ensemble de la capture, particulièrement la partie non retenue, en identifiant les espèces capturées, les tonnages par espèce et en prenant des mesures de tailles. |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00109/21976/19586.pdf |
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| Battaglia, Andre; Trenkel, Verena; Rochet, Marie-joelle. |
| The end effect in trawl catches is defined as the proportion of the fish catch taken during shooting and hauling of the net, a period excluded from that nominally referred to as haul duration. If important, this effect will lead to biased abundance estimates, because the swept area will be underestimated. An experimental survey was carried out to compare catch numbers obtained in standard research 30-min hauls with those from 0-min hauls, the latter referring to the trawl being hauled as soon as the trawl geometry stabilized on the seabed. Average catch ratios (0-min/30-min hauls) ranged from 0.05 (s.d. 0.06) for sole to 0.34 (s.d. 0.64) for hake, indicating that the end effect might be more important and more variable for highly mobile species. As a... |
| Tipo: Text |
Palavras-chave: Trawl survey; Bias; Abundance index. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/2006/publication-1686.pdf |
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| Rochet, Marie-joelle; Trenkel, Verena; Peronnet, Isabelle. |
| Discards of the French trawler fleet operating in the Celtic Sea in 1997 were studied. Twenty-six trips, representing 0.8% of the total fishing effort, were sampled. This fleet consists of three métiers, benthic trawlers, demersal trawlers and Nephrops trawlers. The fleet discarded an estimated 30,000 tons of animals in 1997, while landing 63,000 tons. The total quantity discarded did not differ among métiers, but the species composition of discards did. Benthic trawlers discarded mainly by-catch species, whereas demersal and Nephrops trawlers discarded primarily their target species. Whiting, megrim, Nephrops and hake were discarded in larger numbers than landed. Hence discards should probably be taken into account in catch-based assessments. However,... |
| Tipo: Text |
Palavras-chave: Espèce non commerciale; Langoustine; Baudroie; Poisson plat; Gadidé; Mer celtique; Echantillonnage des rejets; Non commercial species; Nephrop; Anglerfish; Flatfish; Gadoid; Trawler; Celtic Sea; Discard sampling. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/2001/rapport-1575.pdf |
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| Fauconnet, Laurence; Trenkel, Verena M.; Morandeau, Gilles; Caill-milly, Nathalie; Rochet, Marie-joelle. |
| To implement an ecosystem approach to fisheries management, there is a need to characterize the total pressure exerted by fisheries at the community level. French onboard observer data were used to derive catch metrics and compare fishing distribution across community components between two sites in the Southern Bay of Biscay. Sample-based rarefaction curves were used to standardize metrics across different active and passive gears, and correct for sample size differences. Six metrics for species, length and functional catch composition were tested. Length and functional metrics were found the most relevant metrics to highlight differences in catches between gears, sites, and gear-site interactions. Significant differences were found between gears, mainly... |
| Tipo: Text |
Palavras-chave: Catch diversity; Gear comparison; Multivariate analyses; Southern Bay of Biscay. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00248/35882/34468.pdf |
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| Cornou, Anne-sophie; Goascoz, Nicolas; Scavinner, Marion; Chassanite, Aurore; Dubroca, Laurent; Rochet, Marie-joelle. |
| Ce document est une synthèse des informations collectées en 2016 à bord des navires de pêche professionnelle dans le cadre de l'action ObsMer. Cette action vise à observer in situ l’activité de pêche et l'ensemble de la capture, particulièrement la partie non retenue, en identifiant les espèces capturées, les tonnages par espèce et en prenant des mesures de tailles. Ce travail s'inscrit dans le cadre d'un partenariat entre le Comite National des Pêches Maritimes et des Élevages Marins (CNPMEM), la Direction des Pêches Maritimes et de l'Aquaculture (DPMA) du Ministère de l’Agriculture et de l'alimentation, et l'Ifremer. |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00418/52945/53885.pdf |
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| Cotter, John; Petitgas, Pierre; Abella, Alvaro; Apostolaki, Panayiota; Mesnil, Benoit; Politou, Chrissi-yianna; Rivoirard, Jacques; Rochet, Marie-joelle; Spedicato, Maria Teresa; Trenkel, Verena; Woillez, Mathieu. |
| Ideas and considerations are put forward for managing fisheries and marine populations using primarily trawl surveys to supply biological and spatial indicators of the state of stocks, and to permit catch per unit effort (CPUE)-based assessments. Trawl surveys seldom allow absolute estimates of fish population sizes but, if appropriately located, timed, and designed, can provide a broad range of information about catchable fish species and the ecosystem that supports them. This information may be more conducive to sustainable management of fisheries than the traditional focus on the abundances of selected stocks. The paper first briefly proposes how survey-based methods might supplement existing fishery-dependent stock assessments, as would be necessary... |
| Tipo: Text |
Palavras-chave: Fishing effort indicator; Fisheries independent assessment; Survey based stock assessment; Spatial indicator; State indicator; Trawl survey; Fisheries management. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6691.pdf |
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| Trenkel, Verena; Pinnegar, John; Rochet, Marie-joelle; Rackham, Brian. |
| Choice of sampling method and survey period can have an important impact on the perception of the structure and dynamics of an ecological community. For the Celtic Sea fish assemblage we compared data obtained by three different trawl surveys: an autumn groundfish survey with a GOV trawl, and a spring and an autumn groundfish survey, both carried out with a Portuguese high-headline trawl. Time-series of abundance estimates were not consistent among surveys for all species and were generally very noisy. An analysis of variance components showed that the sampling method contributed more to the variance in abundance estimates compared to survey period, interannual variability, or even sampling variance. Overall community assessments based on indicators such... |
| Tipo: Text |
Palavras-chave: Trawl; Survey; Species diversity; Size spectrum; Celtic Sea; Abundance. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/2004/publication-899.pdf |
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| Rochet, Marie-joelle. |
| Density dependence means that exploited fish populations exhibit earlier maturity, a faster growth rate, increased fecundity and reduced egg size. Here, the consequences of these effects on population dynamics, the estimation of spawning biomass per recruit and associated biological reference points are examined by a simulation model. The model is a self-regenerating model in which the population parameters (age at maturity, growth, fecundity, egg size) vary according to three classes of population abundance. Early life stages are characterized by a size-dependent growth and mortality model. It is concluded that spawning per recruit is an ambiguous concept because, if density dependence occurs in the adult population, the spawning biomass of a cohort is... |
| Tipo: Text |
Palavras-chave: Teleost fishes; Population dynamics; Life history; Density dependence; Biological reference points. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-485.pdf |
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| Registros recuperados: 96 | |
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