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| Registros recuperados: 15 | |
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| Gatti, Paul; Méhault, Sonia; Morandeau, Fabien; Morfin, Marie; Robert, Marianne. |
| We assessed the impact of an additional 100 mm square mesh cylinder (SMC) on the selective property of the demersal whitefish trawl in the Celtic Sea. Sea trials were conducted on board a French trawler using twin trawl rigging. We tested the effects of the position of the SMC (in front of and behind the mandatory 100 mm square mesh panel) and of the insertion of a dispersive float. Selectivity analysis revealed the 50% retention length () to be greater than the Minimum Conservation Reference Sizes regardless of species (haddock, whiting or megrim) or rigging configuration. Results did not reveal a clear effect of the SMC position. However, the insertion of the float led to a decrease in selection ranges suggesting enhanced contact probabilities with the... |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00600/71236/73595.pdf |
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| Robert, Marianne; Cortay, Aurore; Morfin, Marie; Simon, Julien; Morandeau, Fabien; Deneubourg, Jean Louis; Vincent, Benoit. |
| Knowledge about fish behavior is crucial to be able to influence the capture process and catch species composition. The rapid expansion of the use of underwater cameras has facilitated unprecedented opportunities for studying the behavior of species interacting with fishing gears in their natural environment. This technological advance would greatly benefit from the parallel development of dedicated methodologies accounting for right-censored observations and variable observation periods between individuals related to instrumental, environmental and behavioral events. In this paper we proposed a methodological framework, based on a parametric Weibull mixture model, to describe the process of escapement attempts through time, test effects of covariates and... |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00663/77553/79457.pdf |
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| Vincent, Benoit; Simon, Julien; Vacherot, Jean-philippe; Morandeau, Fabien; Larnaud, Pascal; Kopp, Dorothee; Mehault, Sonia; Morfin, Marie; Savina-rolland, Marie; Marc, Emilie. |
| The Lorient flume tank is an hydrodynamic facility available for any qualification and observation of submerged objects in still or moving water. It is a closed loop circulating tank filled with fresh water. The fluid is moved with a 70 kW pump-motor with a velocity between 0 and 1 m/s and homogenized with a series of pressure drop systems. The overall dimensions are 24.50 m long, 7.50m wide and 3.30 m high. The part where experiments can be set up is 12m long, 2.6 m wide and 1.5 m deep. A mobile bottom belt can be synchronized with the water flow velocity and enables to simulate the seabed velocity relatively to a towed object. The overall process of the facility is controlled by a user friendly interface. |
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| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00436/54803/56299.pdf |
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| Morfin, Marie; Fromentin, Jean-marc; Jadaud, Angelique; Bez, Nicolas. |
| This study analyzes the temporal variability/stability of the spatial distributions of key exploited species in the Gulf of Lions (Northwestern Mediterranean Sea). To do so, we analyzed data from the MEDITS bottom-trawl scientific surveys from 1994 to 2010 at 66 fixed stations and selected 12 key exploited species. We proposed a geostatistical approach to handle zero-inflated and non-stationary distributions and to test for the temporal stability of the spatial structures. Empirical Orthogonal Functions and other descriptors were then applied to investigate the temporal persistence and the characteristics of the spatial patterns. The spatial structure of the distribution (i.e. the pattern of spatial autocorrelation) of the 12 key species studied remained... |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00087/19860/17507.pdf |
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| Lavialle, Gael; Morfin, Marie; Simon, Julien; Morandeau, Fabien; Vimard, Mathieu; Larnaud, Pascal. |
| In the context of the new European Common Fisheries Policy and in particular the Landing Obligation, the two Producers Organisations, COBRENORD and OPN launched the REJEMCELEC project in partnership with IFREMER and net suppliers. It was set in a complementary way to the CELSELEC project. The main goal is to reduce whiting, haddock and pelagic discards for single bottom trawlers fleets targeting whiting, squids, cuttlefish and monkfish within the Western Channel. A specific fleet targeting hake and John Dory in Celtic Sea during summer (around Scilly Island) was also studied in order to reduce discards of small haddock, hake and boarfish. After a state of the art, an analysis of quantitative data and various workshops organized in partnership between... |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00483/59493/62412.pdf |
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| Merillet, Laurene; Mehault, Sonia; Rimaud, Thomas; Piton, Corentine; Morandeau, Fabien; Morfin, Marie; Kopp, Dorothee. |
| In the context of the landing obligation set by the new Common Fisheries Policy (CFP), Norway lobster Nephrops norvegicus was identified as a species likely to have high survival rate when discarded in the bottom trawl fishery of the Bay of Biscay. Previous studies in this area reported a survival rate between 30% and 51%, but the experiments were done on a limited monitoring period and the seasonal variations were not investigated. This study was designed to obtain a reliable value for survival rate after a 14-day monitoring period in onshore tanks allowing considering delayed mortality. The study also tested the effect on the survival rate of using a discarding chute system, a sorting device that was made mandatory on the 1st of January 2017 for Nephrops... |
| Tipo: Text |
Palavras-chave: Nephrops norvegicus; Sorting process; Captivity; Vitality; Season; Discard survival. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00407/51864/52608.pdf |
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| Vogel, Camille; Kopp, Dorothee; Morandeau, Fabien; Morfin, Marie; Mehault, Sonia. |
| In the English Channel and Southern Bight, French demersal trawlers target a mix of demersal species including whiting (Merlangius merlangus). The discard ban to be implemented in January 2016 motivated fishermen to look for technical measures to reduce unwanted catches of undersized individuals (<27 cm). From 2008–2014, 18 different gear configurations were tested for bycatch reduction on board fleets of vessels of 16–20 m and 20–24 m. Selective devices tested included grids, square mesh panels (SMP), square mesh cylinders (SMC), various combinations of these devices and large mesh trawls. Using the catch comparison method, our results focus on six devices that proved efficient to reduce catches of undersized whiting, equally divided between the two... |
| Tipo: Text |
Palavras-chave: Square mesh; Sorting grids; Fishing gear technology; Merlangius merlangus; Catch comparison; GLMM. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00384/49553/50079.pdf |
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| Morfin, Marie; Kopp, Dorothee; Benoît, Hugues P.; Méhault, Sonia. |
| Two vitality index approaches have been demonstrated to be good proxies of discard survival in similar fishing and environmental conditions: Reflex Action Mortality Predictors combined with injuries (RI) scores that measure the proportion of impaired reflexes and injuries, and a simpler, quicker, but less precise approach based on ordinal categories related to fish body movements and injuries (semi-quantitative assessment, SQA). This study assessed and compared these two approaches for five species (two flatfishes, skates, a seabass and a catshark) discarded in a coastal otter trawl fishery in the Bay of Biscay. All species displayed good vitality status according to both indices and were not very sensitive to the fishing nor their biological conditions.... |
| Tipo: Text |
Palavras-chave: Discard survival; Vitality indicators; Reflex Action Mortality Predictor; Bay of Biscay; Coastal otter trawl fishery. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00466/57817/60417.pdf |
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| Saraux, Claire; Fromentin, Jean-marc; Bigot, Jean-louis; Bourdeix, Jean-herve; Morfin, Marie; Roos, David; Van Beveren, Elisabeth; Bez, Nicolas. |
| Understanding the ecological and anthropogenic drivers of population dynamics requires detailed studies on habitat selection and spatial distribution. Although small pelagic fish aggregate in large shoals and usually exhibit important spatial structure, their dynamics in time and space remain unpredictable and challenging. In the Gulf of Lions (north-western Mediterranean), sardine and anchovy biomasses have declined over the past 5 years causing an important fishery crisis while sprat abundance rose. Applying geostatistical tools on scientific acoustic surveys conducted in the Gulf of Lions, we investigated anchovy, sardine and sprat spatial distributions and structures over 10 years. Our results show that sardines and sprats were more coastal than... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00226/33739/32151.pdf |
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| Registros recuperados: 15 | |
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