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| Registros recuperados: 57 | |
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| Meillat, Marc; Dupouy, Herve; Bavouzet, Gerard; Kergoat, B.; Morandeau, Fabien; Gaudou, Olivier; Vacherot, Jean-philippe. |
| The fishery for benthic species (Monkfish, Megrim, Rays, etc ... ) represents for the surrounder countries of the Celtic Sea and the Bay of Biscaye one of the most important activities . An estimate of the discards of the main species resulting from the sorting practice onboard of the trawlers participating in this fishery was made in 1985 and 1991. it was concluded that an important quantity of juveniles of Rays, Megrim and Monkfish are discarded each year causing an important mortality. The aim of the present paper is to present the preliminary results of a selectivity grid fixed on a bottom trawl to limit as possible the discards. Three different grids were tested at sea during surveys with different results. The major problem is due to difference in... |
| Tipo: Text |
Palavras-chave: Chalut sélectif; Grille; Mer Celtique; Golfe de Gascogne; Baudroies; Sardines; Raies; Selectivity; Grid; Trawl; Celtic Sea; Bay of Biscaye; Monkfish; Megrim; Rays. |
| Ano: 1991 |
URL: https://archimer.ifremer.fr/doc/00394/50567/51258.pdf |
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| Djeghri, Nicolas; Atkinson, Angus; Fileman, Elaine S.; Harmer, Rachel A.; Widdicombe, Claire E.; Mcevoy, Andrea J.; Cornwell, Louise; Mayor, Daniel J.. |
| There has been an upsurge of interest in trait-based approaches to zooplankton, modelling the seasonal changes in the feeding modes of zooplankton in relation to phytoplankton traits such as size or motility. We examined this link at two English Channel plankton monitoring sites south of Plymouth (L4 and El). At L4 there was a general transition from diatoms in spring to motile microplankton in summer and autumn, but this was not mirrored in the succession of copepod feeding traits; for example the ambushing Oithona similis dominated during the spring diatom bloom. At nearby El we measured seasonality of food and grazers, finding strong variation between 2014 and 2015 but overall low mesozooplankton biomass (median 4.5 mg C m(-3)). We also made a seasonal... |
| Tipo: Text |
Palavras-chave: Copepod; Zooplankton biomass; Feeding; Selectivity; Intraguild predation; Predator-prey size ratio; Western Channel Observatory; Sloppy feeding. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00616/72783/83484.pdf |
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| Joksimovic, Aleksandar; Regner, Slobodan; Sacchi, Jacques. |
| Selectivity curves of pandora (Pagellus erythrinus, L. 1758) have been estimated in the area of the Montenegrin shelf (South Adriatic), for trawls with bar mesh sizes of 13.5, 16.1, 17.5, 22 and 35 mm (according to national legislation in Montenegro bar mesh size is measured from knot to knot which is, according to Commission Regulation (EC) No. 129/2003, stretched mesh size divided by 2). Although the existing national legislation prescribes that the minimum mesh size of the trawl be not smaller than 20 mm, trawls with forbidden mesh sizes are often used in this area. Results obtained showed that meshes smaller than 20 mm (13.5 mm, 16.1 mm, 17.5 mm) catch large numbers of immature individuals, since the length of 50% retention (L50%) for all these meshes... |
| Tipo: Text |
Palavras-chave: Pagellus erythrinus; Trawl mesh size; Selectivity; Montenegrin shelf (South Adriatic). |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00020/13134/10177.pdf |
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| Lamothe, Julien; Larnaud, Pascal; Fiche, Marion; Robert, Marianne; Morandeau, Fabien; Vacherot, Jean-philippe; Scavinner, Marion; Simon, Julien. |
| In the context of the new European Common Fisheries Policy and in particular the Landing Obligation, this report synthesizes the trials which were carried out between 2014 and 2016 on French bottom trawlers operating in the Celtic Sea and Western Channel, to decrease their discards. All the detail of the experiments and their results are attached in the voluminous appendices. After a state of the art and various workshops organized in partnership between fishermen, equipment manufacturers and scientists, 3 basic devices were selected for the trials, according to the main fisheries: - 100 mm square meshes cylinder - SMC - (in addition to the mandatory 100mm and 120 mm square mesh panels - SMP) with or without scaring floats ; - Extension + codend in... |
| Tipo: Text |
Palavras-chave: Sélectivité; Mer Celtique; Cylindre à mailles carrées; T90; Grille à baudroie; Rejets; Églefin; Merlan; Sanglier; Selectivity; Celtic Sea; Square mesh cylinder; T90; Monkfish grid; Discards; Haddock; Whiting; Boarfish. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00403/51488/52084.pdf |
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| Reynal, Lionel; Guyader, Olivier; Pau, Cedric; Mathieu, Heloise; Dromer, Clement. |
| In order to improve the sustainable development of FADs fishing, it is important to reduce the capture of juveniles or species that need a decrease in fishing effort, temporarily or definitively. Through previous statistics data coming from commercial fishing trips and new experimental fishing trips, we compared different gears and techniques selectivity for the species and the size of the capture around FADs. We also compared different type of bait used, the best hours to fish for better productivity and to target adults. Finally we look at the influence of the FAD distance from shore. We observed that fishers’ strategies have a critical influence on FADs setting and targeted species. The further the FAD is deployed and the better yield the fisherman... |
| Tipo: Text |
Palavras-chave: Anchored FAD; Artisanal and small scale fishing; Selectivity. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00230/34091/32527.pdf |
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| Gilman, Eric; Chaloupka, Milani; Bach, Pascal; Fennell, Hannah; Hall, Martin; Musyl, Michael; Piovano, Susanna; Poisson, Francois; Song, Liming. |
| Fisheries can profoundly affect bycatch species with ‘slow’ life history traits. Managing bait type offers one tool to control species selectivity. Different species and sizes of marine predators have different prey, and hence bait, preferences. This preference is a function of a bait’s chemical, visual, acoustic and textural characteristics and size, and for seabirds the effect on hook sink rate is also important. We conducted a global meta-analysis of existing estimates of the relative risk of capture on different pelagic longline baits. We applied a Bayesian random effects meta-analytic regression modelling approach to estimate overall expected bait-specific catch rates. For blue shark and marine turtles, there were 34% (95% HDI: 4–59%) and 60% (95%... |
| Tipo: Text |
Palavras-chave: Bait; Bycatch; Longline; Mitigation; Selectivity; Tuna. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75536/76441.pdf |
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| Vincent, Benoit; Di Cesare, Noëlie; Simon, Julien. |
| The assessment of mesh resistance to opening is a key factor when coming to fishing gear design to study or optimize the fishing selectivity process. Different authors proposed methodologies to achieve twine flexural rigidity identification and mesh opening angle at rest. Their experimental protocols could rely on complex installations and instrumentation, and identification needs dedicated models or software with possible important set up time. Sometimes, different flexural rigidity and rest angle values for a given netting type were proposed depending on identification or experimental conditions, leading to difficulties to choose a value for implementation in netting structures simulation software. The new methodology proposed in this article is based on... |
| Tipo: Text |
Palavras-chave: Fishing net mechanics; Twine flexural rigidity; Numerical simulation; Selectivity; Fishing. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00613/72541/71615.pdf |
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| Vogel, Camille; Kopp, Dorothee; Mehault, Sonia. |
| On January 1st, 2016, the French mixed Nephrops and hake fishery of the Grande Vasière, an area located in the Bay of Biscay, fell under the discard ban implemented as part of the new European Common Fisheries Policy. The fleet records historically high levels of discard despite numerous gear selectivity studies. Together with high discards survival, new technological solutions to minimize catches of undersized individuals could justify local exemptions from the discard ban. Our study focuses on the effects of two selective devices, a square mesh cylinder (SMC) and a grid, on the escapement of undersized individuals and discard reduction. Relative catch probability of the modified gear compared with the traditional gear was modelled using the catch... |
| Tipo: Text |
Palavras-chave: Nephrops; European hake; Discard ban; Gear technology; Catch comparison; Selectivity. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00356/46717/46906.pdf |
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| Loaec, Henri; Morandeau, Fabien; Meillat, Marc; Davies, Peter. |
| There are different approaches to selectivity, including increasing cod-end mesh size, square mesh panels and rigid grids. Selectivity grids have traditionally been produced to be as rigid as possible to maintain spacing but this can result in heavy, expensive grids, handling problems and brittleness. This paper presents an alternative approach using flexible polyurethane polymers to produce lightweight inexpensive grids with much improved damage tolerance and ease of handling, which also possess interesting selectivity characteristics. The material selection, design and development tests are described first, then preliminary sea trial results are presented. A flexible grid with a 20 mm spacing between bars performed successfully and enabled a reduction in... |
| Tipo: Text |
Palavras-chave: Damage resistance; Polyurethane; Nephrops; Grid; Size selection; By catch; Selectivity. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1690.pdf |
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| Rochet, Marie-joelle; Catchpole, Tom; Cadrin, Steve. |
| Discarding is considered by many as an important problem in world fisheries. In many regions, data collection onboard commercial vessels has intensified, and the understanding of both human and ecological drivers of discards is improving quickly. Discarding patterns vary widely across regions, fisheries, gears, and species. Fishers' responses to regulations and markets explain these complex patterns, on top of resource availability partly driven by environmental fluctuations. This expanded knowledge base provides an appropriate basis for discussing the discard mitigation measures proposed in various settings. In September 2012, a theme session was convened at the ICES Annual Science Conference in Bergen, Norway, to discuss these issues. This themed set of... |
| Tipo: Text |
Palavras-chave: Bycatch and discards; Catch quotas; Compliance; Landing obligation; Landing quotas; Market incentives; Minimum landing sizes; Onboard observer programmes; Selectivity. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00202/31353/29911.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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| Leonardi, Sophie; Rubin, Alex; Meillat, Marc; Coppin, Franck; Delpech, Jean-paul; Morandeau, Fabien; Larnaud, Pascal. |
| Ce rapport fait la synthèse des travaux réalisés en 2008 et en 2009 au cours du programme Selecmer. Celui-ci, réalisé à l'initiative des professionnels de la pêche en partenariat avec l'Ifremer, avait pour objectif de travailler à améliorer la sélectivité du chalut de fond qu'ils utilisent afin de diminuer les rejets des individus hors-tailles1, en particulier pour le merlan, tout en limitant les pertes commerciales immédiates. Une première phase a consisté à tester l'efficacité de fenêtres à mailles carrées. La deuxième phase a eu pour objectif de développer une grille sélective. Des essais en bassin et des campagnes vidéo en mer ont permis d'apporter des ajustements aux dispositifs sélectifs. L'ensemble des essais de sélectivité à bord des navires de... |
| Tipo: Text |
Palavras-chave: Professional fishermen; Square mehs; Flume tank; Selective grid; North Sea; Channel; Bottom trawl; Selectivity; Fishing; Professionnels; Mailles carrées; Campagnes à la mer; Bassin d'essais; Grille sélective; Mer du Nord; Manche; Chalut de fond; Sélectivité; Pêche. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/rapport-6776.pdf |
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| Registros recuperados: 57 | |
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