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Registros recuperados: 58 | |
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Marchal, Paul. |
A quantitative comparison between metiers and resulting catch profiles was carried out for seven French demersal and pelagic fleets operating in the North Sea, the eastern Channel, and the Bay of Biscay. Typologies for four metiers have been attempted, based on different factors (gear, mesh size, fishing ground, and/or a priori target species), data sources (logbooks or harbour enquiries), and aggregation levels. Catch profiles were selected through cluster analysis. The linkage between metiers and catch profiles was quantified using uncertainty coefficients, which depended on the metier typology being used and the fleet under consideration, but were not subject to substantial inter- or intra-annual fluctuations. Future catch profiles and metiers were... |
Tipo: Text |
Palavras-chave: Uncertainty coefficients; Metiers; Fleets; Fishing intention; Catch profiles. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4075.pdf |
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Marchal, Paul; Andersen, Jesper Levring; Aranda, Martin; Fitzpatrick, Mike; Goti, Leyre; Guyader, Olivier; Haraldsson, Gunnar; Hatcher, Aaron; Hegland, Troels Jacob; Le Floc H, Pascal; Macher, Claire; Malvarosa, Loretta; Maravelias, Christos D.; Mardle, Simon; Murillas, Arantza; Nielsen, J. Rasmus; Sabatella, Rosaria; Smith, Anthony D. M.; Stokes, Kevin; Thoegersen, Thomas; Ulrich, Clara. |
This study compares the details and performance of fisheries management between the EU and a selection of other countries worldwide: Iceland, New Zealand, and Australia, which are considered in many respects to be among the most advanced in the world in fisheries management. Fisheries management in the EU, Iceland, Australia, and New Zealand has developed following different paths, despite being based on similar instruments and principles. Iceland, Australia, and New Zealand have been at the forefront of developing management practices such as stakeholder involvement, legally binding management targets (Australia, New Zealand), individual transferable quotas, and discard bans (Iceland, New Zealand). The EU has since the beginning of the 21st century taken... |
Tipo: Text |
Palavras-chave: Australia; Comparative review; European Union; Fisheries management; Iceland; New Zealand. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00312/42305/41699.pdf |
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Vermard, Youen; Marchal, Paul; Mahevas, Stephanie; Thebaud, Olivier. |
The scope of this paper is to describe, evaluate, and forecast fishing trip choices of the Bay of Biscay pelagic fleet using random utility modeling (RUM). First, alternative fishing trip choices of this fleet were identified using multivariate statistical methods based on species landings weighted by value and defined as distinct fishing activity or fisheries (termed metiers). A RUM was specified, which included trip components as attributes during the period 20012004 ( a lagged percentage of the value per unit of effort of the main species caught, total value per unit of effort, and inertia in terms of changes from one metier to another). For the main metiers, the proportion of correct effort allocation is 90% during the calibration period of 2001-2004.... |
Tipo: Text |
Palavras-chave: Management; Métier; Fishing effort; Fisher's behavior; RUM. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6096.pdf |
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Cresson, Pierre; Timmerman, Charles-andre; Couvreur, Clemence; Denamiel, Margaux; Lepretre, Marie-anais; Marchal, Paul. |
This document summaries major results about the diet of sole Solea solea and plaice Pleuronectes platessa in the English Channel, collected in the framework of the VARITROPH project. Both species have a similar diet, based on crustaceans, but plaice exhibit a larger diversity of secundary species (bivalves, annelids and echinoderms) than sole (annelids only). Diversity of the preys for plaice is explained by differences between size classes. Diet of small individuals is less diverse than the diet of large individuals. Trophic similarity between sole and plaice is also exhibited when comparing ontogenic changes of trophic levels, that are pretty similar for both species, and consistent with a diet based on small invertebrates. |
Tipo: Text |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00675/78718/80904.pdf |
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Cresson, Pierre; Timmerman, Charles-andre; Cordier, Remy; Couvreur, Clemence; Denamiel, Margaux; Engler, Alexandra; Lebon, Fabien; Lepretre, Marie-anais; Marchal, Paul. |
This document summaries major information about the diet of mackerel Scomber scombrus in the English Channel, collected during the VARITROPH project. Mackerel consume quite exclusively copepods, with low effect of size on both diet and trophic level. |
Tipo: Text |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00675/78716/80902.pdf |
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Cresson, Pierre; Timmerman, Charles-andre; Denamiel, Margaux; Millet, Lucie; Marchal, Paul. |
This document summaries the major findings about the diet of whiting Merlangius merlangus in the English Channel, in the framework of the VARITROPH project. Whiting diet is based on several main preys, with an ontogenic variation. Individuals lower than 30 cm mostly fed on crustaceans, while diet of larger individuals is based on cephalopods and fishes. As a result, trophic level show 2 phases, one increasing at the early life stages, and a constant trophic level for individuals larger than 30 cm. |
Tipo: Text |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00675/78717/80903.pdf |
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Mahevas, Stephanie; Vermard, Youen; Hutton, Trevor; Iriondo, Ane; Jadaud, Angelique; Maravelias, Christos D.; Punzon, Antonio; Sacchi, Jacques; Tidd, Alex; Tsitsika, Efthymia; Marchal, Paul; Goascoz, Nicolas; Mortreux, Serge; Roos, David. |
The impact of the fishing effort exerted by a vessel on a population depends on catchability, which depends on population accessibility and fishing power. The work investigated whether the variation in fishing power could be the result of the technical characteristics of a vessel and/or its gear or whether it is a reflection of inter-vessel differences not accounted for by the technical attributes. These inter-vessel differences could be indicative of a skipper/crew experience effect. To improve understanding of the relationships, landings per unit effort (lpue) from logbooks and technical information on vessels and gears (collected during interviews) were used to identify variables that explained variations in fishing power. The analysis was undertaken by... |
Tipo: Text |
Palavras-chave: Catchability; Fishing power; GAM; GLM; Skipper skill; Technical characteristics. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00049/16043/15172.pdf |
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Marchal, Paul; Ulrich, Clara; Pastoors, M. |
The scope of this study is to investigate the extent to which area-based management may have influenced the fishing efficiency of the Danish and Dutch demersal fleets harvesting cod, plaice and sole in the North Sea. Special consideration is given to the 'plaice box', a restricted area where fishing is prohibited to towed-gear fleets of horsepower exceeding 300 hp. An index of fishing power is calculated as the log-ratio between the catch per unit effort (CPUE) of any vessel and some survey abundance index. Annual trends in fishing are calculated as the year-effect derived from a general linear model (GLM) analysis of the index of fishing power. The fishing efficiency of Danish gill-netters and, to some extent, Danish seiners, has overall increased inside... |
Tipo: Text |
Palavras-chave: Fishing efficiency; Plaice box; Fisheries management; North Sea; Demersal fisheries. |
Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00589/70118/68112.pdf |
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Garcia, Dorleta; Urtizberea, Agurtzane; Diez, Guzman; Gil, Juan; Marchal, Paul. |
Deepwater fish are characterized by long lifespans, late maturity and low productivity. This implies slow recovery from low biomass levels and it is, therefore, important to manage these stocks correctly to avoid overfishing. However, these stocks are generally data poor, which it makes difficult to apply quantitative assessment models on which to base their management. The management strategy evaluation (MSE) approach consists in evaluating the performance of management strategies by simulation before their implementation. In the evaluation, the main sources of uncertainty in a fishery system and its management process should be taken into account in order to find robust management strategies. Thus, the MSE approach is relevant to the management of... |
Tipo: Text |
Palavras-chave: Bio-economic modelling; Deep-sea fisheries; Harvest control rules; Management strategy evaluation; Norway; Bay of Biscay; Gibraltar; Atlantic Ocean. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00176/28760/27231.pdf |
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Marchal, Paul; Francis, Chris; Lallemand, Philippe; Lehuta, Sigrid; Mahevas, Stephanie; Stokes, Kevin; Vermard, Youen. |
Managing adequately the exploitation of commercial species subject to technical interactions is a key step towards the ecosystem approach to fisheries. We evaluate here, using a bio-economic modelling approach building on the ISIS-Fish simulation platform, the relative impact of total allowable commercial catches (TACC) and of taxes applicable to over-quota landings (deemed value) on the sustainability of a selection of species exploited by the New Zealand hoki (Macruronus novaezelandiae) fishery. We investigate some aspects of the hoki mixed fisheries, consisting of four fleets and nineteen metiers, by considering the technical interactions between hoki and Southern hake (Merluccius australis). The dynamics of effort allocation were modelled using gravity... |
Tipo: Text |
Palavras-chave: Fleet dynamics; New Zealand hoki fishery; Deemed value; Fisheries management. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11168/7521.pdf |
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Amelot, Morgane; Bastleer, Jurgen; Foucher, Eric; Girardin, Raphael; Marchal, Paul; Poos, Jan Jaap; Sys, Klaas. |
Rajidae stocks (Raja clavata, Raja brachyura, Raja montagui, Raja microocellata, Leucoraja naevus and Raja undulata) in the English Channel and North Sea (ICES divisions 3a, 4 and 7d) are actually managed as a complex (“skates and rays”) and subject to a single TAC. TAC advices from the ICES are based on scientific survey indices trends from each species. Rajidae catches are mainly bycatch from flatfish fisheries such are sole (Solea solea) and plaice (Pleuronectes platessa) fisheries. Furthermore, because of their top predator position as well as their life history, Rajidae are species sensitive to overfishing. These different factors have led to a revision in stock assessment methods. ICES classified Rajidae as category 3 data limited stocks. The lack of... |
Tipo: Text |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00620/73220/72433.pdf |
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Vermard, Youen; Lehuta, Sigrid; Mahevas, Stephanie; Thebaud, Olivier; Marchal, Paul; Gascuel, Didier. |
It is increasingly recognized that fisher‟s behavior should be taken into account to understand and predict fishery dynamics, in particular in response to management. ISIS-Fish is a spatially and seasonally explicit modeling framework especially designed to couple populations and fleets dynamics and explore the impact of various management measures on mixed fisheries. It has already been set up using a static fishing effort allocation (corresponding to an average historical pattern) between the various métiers to simulate the pelagic fishery in the Bay of Biscay. We present here the integration of a fleet dynamics model. This model is derived from a Random Utility Model simulating métiers choice using as explanatory variables the past value per unit... |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00107/21858/19449.pdf |
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Delavenne, Juliette; Marchal, Paul; Vaz, Sandrine. |
Classifying marine habitats is a growing research field and is of increasing interest to spatial planners and managers. Most studies have predominantly focused on the seabed to determine benthic habitat types, and only limited attention has been paid to the water column. Classification projects aim at identifying candidate management units for the application of various regional or national regulations such as the European Water Framework Directive. Here, we propose a seasonal classification of the water column in the eastern English Channel, which we validated with biological data. For the three tested compartments, phytoplankton, zooplankton and pelagic fishes, the validation results were satisfactory, with recall values (i.e. percentage of observations... |
Tipo: Text |
Palavras-chave: Eastern English Channel; Pelagic typology; Clustering analysis; Seasonality. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00125/23655/22689.pdf |
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Amelot, Morgane; Batsleer, Jurgen; Foucher, Eric; Girardin, Raphael; Marchal, Paul; Poos, Jan Jaap; Sys, Klaas. |
Six Rajidae stocks (Raja clavata, Raja brachyura, Raja montagui, Raja microocellata, Leucoraja naevus and Raja undulata) are currently exploited in the English Channel and North Sea area (ICES divisions 3a, 4 and 7d) and subject to a TAC regulation. This TAC is set based on monospecific approaches (abundance indices) when mangement is complex based. However, stock status disparities exist between these species. In this context a multispecific MSE (Management Strategy evaluation) framework has been developped based on DLMTool package from R. The main objective was to estimate the complex management impact at the different steps of stocks management (data collect, assessment, management measures implementation). The species species assessement and ... |
Tipo: Text |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00652/76423/77495.pdf |
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Marchal, Paul. |
Ce mémoire présente une contribution à la recherche sur la dynamique de la mortalité par pêche (F) et son impact sur la gestion des ressources halieutiques. La première étape de cette démarche a été de réduire la complexité des systèmes halieutiques étudiés, en regroupant les bateaux et leurs activités en flottilles et métiers respectivement. Plusieurs méthodes existent pour définir les métiers, certaines basées sur les variables d’entrée (engin, zone de pêche, espèces cibles), d’autres sur les variables de sortie (profils de capture). Une comparaison de ces méthodes pour les flottilles françaises indique que les meilleures correspondances sont obtenues pour les flottilles les plus sélectives (e.g., chalutiers pélagiques, fileyeurs). Une fois les... |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00031/14251/11535.pdf |
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Cormon, Xochitl; Kempf, Alexander; Vermard, Youen; Vinther, Morten; Marchal, Paul. |
During the last 15 years, northern European hake (Merluccius merluccius) has increased in abundance, and its spatial distribution has expanded in the North Sea region in correlation with temperature. In a context of global warming, this spatial shift could impact local trophic interactions: direct impacts may affect forage fish through modified predator–prey interactions, and indirect impacts may materialize through competition with other resident predators. For instance, North Sea saithe (Pollachius virens) spatial overlap with hake has increased while saithe spawning-stock biomass has decreased recently notwithstanding a sustainable exploitation. In this context, we investigated the range of potential impacts resulting from most recent hake emergence in... |
Tipo: Text |
Palavras-chave: Hake; Interspecific competition; Maximum sustainable yield; Multispecies stock assessment; Norway pout; Predator-prey interactions; Saithe; Simple foodweb; SMS. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00327/43794/45917.pdf |
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Di Pane, Julien; Gendrot, F.; Giraldo, Carolina; Marchal, Paul; Koubbi, Philippe; Loots, Christophe. |
In the present study, the histological-based condition of common sole (Solea solea) larvae in the English Channel was evaluated to assess the relevance of experimentally-calibrated indices for wild collected specimens. Based on topographical observation of foregut, midgut, hindgut, liver and pancreas, each of the 202 larvae analysed was attributed one of the six grades of a condition index that was developed for sole in the nineties. In parallel, a synthetic table of 20 criteria historically used as condition indicators was created from an extensive review of the literature. These criteria were related to tissular integrity, cells height, nuclei, presence of prey and vacuolisation of the same five target organs. For each larva, each criterion was scored on... |
Tipo: Text |
Palavras-chave: Condition index; Eastern English Channel; Fish larvae; Histology; Solea solea; Starvation. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00601/71325/69754.pdf |
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Registros recuperados: 58 | |
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