Consulta: subjectFacets:"Trawl"
Registros recuperados: 15
Data/hora: 13/06/2024 14:23:25

Etude numérique du train de pêche d'un chalutier (DEA)
Provedor de dados: 5
Autores: Theret, Francois.
IFREMER aims at digitalizing trawl gear in order to reach two goals: on the one hand, participating in the realisation of a computer assisted trawl conception software; on the other hand, being able to study quickly and easily the influence of different adjustment parameters on the shape of the trawl in order to indicate to the skipper, if possible in real time, the optimal adjustment for the conditions he's in. From an international point of view, there are only two strategies to approach this problem: - the first strategy is based on statistical studies on the existing nets (almost limited to their reproduction on different scales), but this approach does not leave much room for innovation as it can only be applied to the same type of nets as those that...
Tipo: Text
Palavras-chave: Experimentation; Optimization; Adjustment; Hydrodynamic; Modelization; Trawl gear; Trawl; Expérimentation; Maquette de chalut; Optimisation; Réglage; Hydrodynamique; Modèle numérique; Train de pêche; Chalut.
Ano: 1990
URL: http://archimer.ifremer.fr/doc/1990/these-3627.pdf

La pêche au vivaneau en Guyane française
Provedor de dados: 5
Autores: Prevost, Etienne.
Traditionally fished by line and conical fishing basket by Venezuelan ships, the red snapper resource off the coast of French Guyana (fish belonging to the Lutjanidae family) has been experiencing intensive fishing since 1984-85 due to the boom in classic fishing techniques and the development of trawl fishing.  The study evaluates the situation of this resource's potential: biology, sampling data, bio-statistics (size and sex), size-weight relationship of the three species, specific composition of the catches, describes fishing devices and prospecting, pinpoints fishing spots, gives a distribution of the Venezuelan and Martinique fishing effort.
Tipo: Text
Palavras-chave: Bow net; Trawl; Fishing line; Franch Guyana; Lutjanidae; Guyane; Chalut; Nasse; Ligne; Engin de pêche; Lutjanidae; Vivaneau.
Ano: 1986
URL: http://archimer.ifremer.fr/doc/1986/rapport-2646.pdf

Preliminary results of a trawl fitted with a selective grid for the fishery of benthic species from Celtic Sea and Bay of Biscay
Provedor de dados: 5
Autores: 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

Direct assessment of anchovy by the Pelgas06 acoustic survey
Provedor de dados: 5
Autores: Masse, Jacques; Mehault, Sonia; Beillois, Pierre; Duhamel, Erwan; Planque, Benjamin; Petitgas, Pierre; Biseau, Alain.
An acoustic survey was carried out in the bay of Biscay from May 1st to May 30th  on board the French research vessel Thalassa. The objective of PELGAS06 survey was to study the abundance and distribution of pelagic fish in the Bay of Biscay. The target species were mainly anchovy and sardine and were considered in a multi-specific context. The results have to be used during ICES working groups in charge of the assessment of sardine, anchovy, mackerel and horse mackerel and in the frame of the Ifremer fisheries ecology program "resources variability"
Tipo: Text
Palavras-chave: Bay of Biscay; Plakton net; Trawl; CUFES; Survey; Acoustic; ICES; PELGAS; Anchovy; Golfe de Gascogne; Filet à plancton; Chalut; CUFES; Campagne; Acoustique; CIEM; PELGAS; Anchois.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/acte-2291.pdf

Characterization and standardization of the Atlantic albacore French pelagic trawl fishery
Provedor de dados: 5
Autores: Nikolic, Natacha; Lauretta, Matthew; Patucca, Audrey; Morandeau, Gilles.
We compiled and analysed logbook data from the French trawl albacore fishery covering the period 1991–2015. The dataset comprised catch and effort data for the French fleet operating in the Bay of Biscay and Celtic Sea, as well as spatiotemporal and gear characteristics. Generalized linear modelling was used to model spatial, seasonal, environmental, and gear covariates of fleet CPUE rates. A long-term index of relative abundance is provided that can be integrated into the stock assessment of North Atlantic albacore. The analysis revealed higher albacore CPUE associated with relatively low sea surface temperature and distinct seasonal effects. The derived abundance trend for the French trawl fishery agreed with the estimated time series of stock abundance...
Tipo: Text
Palavras-chave: Albacore; Catch; Atlantic; Trawl; Fisheries; Stock.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00461/57256/59283.pdf

No more reason for ignoring gelatinous zooplankton in ecosystem assessment and marine management: Concrete cost-effective methodology during routine fishery trawl surveys
Provedor de dados: 5
Autores: Aubert, A.; Antajan, Elvire; Lynam, C.; Pitois, S.; Pliru, A.; Vaz, Sandrine; Thibault, D.
Gelatinous zooplankton, including cnidarians, ctenophores, and tunicates (appendicularians, pyrosomes, salps and doliolids), are often overlooked by scientific studies, ecosystem assessments and at a management level. Despite the important economic consequences that they can have on human activities and on the marine foodweb, arguments often related to the costs of monitoring or their coordination, or simply negligence, have resulted in the absence of relevant monitoring programs. A cost-effective protocol has been applied on trawling from existing fishery surveys conducted by national laboratories in England and France. The testing phase has successfully demonstrated the adequacy of such a tool to sample macro- and mega-zooplankton gelatinous organisms in...
Tipo: Text
Palavras-chave: Gelatinous zooplankton; Jellyfish; Monitoring; Trawl; Marine management; MSFD.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00416/52771/53934.pdf

Optimisation of trawl energy efficiency under fishing effort constraint
Provedor de dados: 5
Autores: Priour, Daniel; Khaled, Ramez.
Trawls energy efficiency is greatly affected by the drag, as well as by the swept area. The drag results in an increase of the energy consumption and the sweeping influences the catch. Methods of optimisation of the trawl design have been developed in order to reduce the volume of carburant per kg of caught fish and consequently the drag per swept area of the trawl. Based on a finite element method model for flexible netting structures, the tool modifies step by step a reference design. For each step the best-modified design, in terms of drag per swept area is kept. Such optimisation can lead to a decrease of the drag or an increase of the swept area. In the second case, that could lead to an increase of fishing effort. To avoid such increase, which could...
Tipo: Text
Palavras-chave: Fishing; Fuel; Fishing gear; Trawl; Optimisation; Fishing effort.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00170/28151/26381.pdf

Different surveys provide similar pictures of trends in a marine fish community but not of individual fish populations
Provedor de dados: 5
Autores: 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

The effect of catch weight on trawl behaviour
Provedor de dados: 5
Autores: Priour, Daniel.
Measurements at sea during fishing trials on bottom trawl, have revealed that the geometry of the trawl is affected by the catch. A series of 27 hauls of around 3h have been carried out during the EFFICHALUT project. This project aimed to find out improvements on the fishing gear in order to reduce the energy consumption. For this project numerous sensors have been used, for bridles tension, doors spread, vertical opening, doors attitude. The measurements show quite clearly that the doors spread decreases and the bridles tension increases along most of the hauls. The doors spread decreases by 1.35m per hour, with a standard deviation of 1.98m/h when the top bridle tension increases of 47kg/h, with a standard deviation of 59kg/h. The mean catch per haul is...
Tipo: Text
Palavras-chave: Trawl; Data; Modelling; Doors spread; Bridle tension; Catch weight.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00186/29761/28208.pdf

The effect of the bottom boundary layer on trawl behaviour
Provedor de dados: 5
Autores: De La Prada, Amelia; Priour, Daniel.
Thirty-seven hauls of a bottom trawl were carried out, as part of a national French project. These sea trials were undertaken in an area with strong currents: up to 1 knot. The measurements at sea of the bottom bridle’s tension show a clear effect of the current. Although the water speed relative to the trawl is constant, when the boat tows with current, the bottom bridle’s tension increases, and when the boat tows against the current, the bottom bridle’s tension decreases. The mean bottom bridle tension is 7840 N and increases with a slope of 1197 N for each m/s of current. The current has almost no effect on the top bridle’s tension: for a mean value of approximately 9810 N, the increment is 106 N for each m/s of current. The modelling of the trawl gear...
Tipo: Text
Palavras-chave: Trawl; Data; Numerical model; Bridle tension; Bottom boundary layer; Water speed.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00266/37710/35800.pdf

Experimental and theoretical study of red mullet (Mullus barbatus) selectivity in codends of Mediterranean bottom trawls
Provedor de dados: 5
Autores: Sala, Antonello; Priour, Daniel; Herrmann, Bent.
The objective of this study was to investigate the effect on Mullus barbatus (red mullet) codend selectivity by increasing the codend mesh size or reducing the number of meshes in the codend circumference. This was performed through experimental sea trials and computer simulations. The sea trials were carried out in the Adriatic Sea using a polyamide codend in order to assess its selectivity, to record morphological (height, width and length) and population size structure parameters of red mullet (Mullus barbatus). The selectivity process in the codend was also simulated with an individual-based model (PRESEMO) and a finite element model (FEMNET) to calculate the codend shapes. By adjusting the behavioural description of red mullet in the simulation, the...
Tipo: Text
Palavras-chave: Mediterranean Sea; Mullus barbatus; Red mullet; Codend shape simulation model; Trawl; Codend selectivity.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2200.pdf

Numerical optimisation of trawls design to improve their energy efficiency
Provedor de dados: 5
Autores: Priour, Daniel.
Trawls energy efficiency is greatly affected by the drag, as well as by the swept area regarding pelagic trawls and by the swept width for bottom ones. The drag results in an increase of the energy consumption and the sweeping influences the catch. In order to reduce the drag per swept area (or width) a numerical tool dedicated to the automatic optimisation of the trawl design has been developed. Based on a finite element method model for flexible netting structures, the tool modifies step by step a reference design. For each step the best-modified design, in terms of drag per swept area (or width), is kept. Such a methodology was used in two cases: which show a 43% increase in energy efficiency regarding the pelagic trawl case and 27% for the bottom trawl...
Tipo: Text
Palavras-chave: Swept width; Swept area; Drag; Fuel consumption; Optimisation; Modelling; Trawl; Fishing gears.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6583.pdf

A digital atlas to link ontogenic shifts in fish spatial distribution to the environment of the eastern English Channel. Dab, Limanda limanda as a case-study
Provedor de dados: 5
Autores: Martin, Corinne; Vaz, Sandrine; Koubbi, Philippe; Meaden, Geoff; Engelhard, Georg H.; Lauria, Valentina; Gardel, Laure; Coppin, Franck; Delavenne, Juliette; Dupuis, Ludovic; Ernande, Bruno; Foveau, Aurelie; Lelievre, Stephanie; Morin, Jocelyne; Warembourg, Caroline; Carpentier, Andre.
The eastern English Channel, which connects the Atlantic Ocean to the North Sea through the Dover Strait, is an area where numerous and often conflicting human activities take place. A cross-border multidisciplinary project called CHARM was initiated to provide knowledge and tools for planners and decision-makers to durably manage the shared marine living resources. One such tool was an atlas of fish spatial distributions and modelled habitats, which was used here to investigate ontogenic and seasonal shifts in fish spatial distribution and habitat through a case-study, the dab Limanda limanda. Survey data for several life-history stages (eggs, larvae, coastal nurseries, &lt; and &gt; 1 year old) and seasons were used to map spatial patterns (using...
Tipo: Text
Palavras-chave: Pleuronectidae; Limanda limanda; Eastern Channel; Spatial distribution; Modelling; Kriging; Ichthyoplankton; Trawl; CUFES.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00008/11942/8646.pdf

An experimental/numerical study of the catch weight influence on trawl behavior
Provedor de dados: 5
Autores: Priour, Daniel; De La Prada, Amelia.
Measurements at sea during fishing trials on bottom trawl have revealed that the geometry of the trawl is affected by the catch. A series of 37 hauls of around 3 h were carried out during the French EFFICHALUT project. The aim of this project was to carry out improvements on the fishing gear in order to reduce energy consumption. For this project, numerous sensors were used: for bridle tension, door spread, vertical opening, and door attitude. The measurements show quite clearly that the door spread decreases and the bridle tension increases during most of the hauls. The door spread decreased by 1.35 m/h, with a standard deviation of 1.98 m/h while the top bridle tension increased by 47 kg/h, with a standard deviation of 59 kg/h. The mean catch per haul...
Tipo: Text
Palavras-chave: Trawl; Data; Modeling; Door spread; Bridle tension; Catch weight.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00239/34990/33525.pdf

Benthic prey production index estimated from trawl survey supports the food limitation hypothesis in coastal fish nurseries
Provedor de dados: 5
Autores: Day, Louise; Le Bris, Hervé; Saulnier, Erwan; Pinsivy, Lucas; Brind'Amour, Anik.
Coastal and estuarine habitats function as nurseries for many commercial marine species. In these ecosystems, the hypothesis that food supply limits juvenile fish density and survival has been widely debated. Direct approaches that test this hypothesis in temperate soft-bottom nurseries are data-intensive as they rely on beam trawl to collect juvenile fish and grab or core to collect their prey within the macrobenthic community. Thus, application has often been limited to a few sampling stations and temporal snapshots. However, scientific beam trawl surveys, conducted periodically in nurseries, sample, besides juvenile fish, benthic invertebrates including potential prey species. Using data collected solely from beam trawl surveys, we tested whether food...
Tipo: Text
Palavras-chave: Young-of-the-year fish; Macrobenthic production; Trawl; Grab; Bay of Biscay; Quantile regression.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00600/71239/69607.pdf