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Registros recuperados: 28 | |
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Mahe, Kelig; Bellamy, Elise; Delpech, Jean-paul; Lazard, Coline; Salaun, Michele; Verin, Yves; Coppin, Franck; Travers-trolet, Morgane. |
Weight–Body Length relationships (WLR) of 45 fish species (37 Actinopterygii and eight Elasmobranchii) were investigated. A total of 31,167 individuals were caught and their biological parameters measured during the four quarters from 2013 to 2015, on five scientific surveys sampling the North-eastern Atlantic Ocean from the North Sea to the Bay of Biscay (ICES Divisions IVb, IVc, VIId, VIIe, VIIg, VIIh, VIIj, VIIIa and VIIIb). Among 45 tested species, all showed a significant correlation between total length (L) and total weight (W). The influence of sex on WLR was estimated for 39 species and presented a significant sexual dimorphism for 18 species. Condition factor (K) of females was always higher than for males. Moreover, a spatial effect on the WLR... |
Tipo: Text |
Palavras-chave: Weight-length relationship; Condition factor; Bay of Biscay; Celtic Sea; English Channel; North Sea; Sexual dimorphism; Seasonality. |
Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00363/47418/47513.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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Trenkel, Verena; Pinnegar, J; Dawson, W; Du Buit, M; Tidd, A. |
The spatial and temporal structure of predator-prey relationships in the Celtic Sea was investigated for 4 commercially important predator species (cod Gadus morhua, hake Merluccius merluccius, megrim Lepidorhombus whiffiagonis, and whiting Merlangius merlangus) using stomach-content and bottom-trawl survey data for the period 1982 to 1995. Blue whiting Micromesistius poutassou were consumed more often during the summer months, whereas mackerel Scomber scombrus and Trisopterus spp. (poor cod T minutus, Norway pout T esmarkii, and bib T luscus) were found more often in predator stomachs during the winter half-year. On a spatial scale, blue whiting was consumed over the shelf edge, in accordance with their higher densities in the environment, while mackerel,... |
Tipo: Text |
Palavras-chave: Spatial distribution; Season; Celtic Sea; Preference; Stomach contents; Diet. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-3619.pdf |
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Perez, Ilan. |
Balanced harvest has been suggested as a new paradigm of fisheries management in order to minimize the impacts of fisheries on marine ecosystems, by distributing the fishing pressure on all species and trophic levels, proportionally to the productivity of each group, to maintain their relative abundance in the ecosystem. However, this exploitation pattern has been criticized by a few scientists arguing that exploitation of all trophic levels may lead to a large ecosystem impact, due to the cumulative effects of fishing along the food web. There is no consensus within the literature about Balanced Harvest implementation and effects because scarce knowledge. Using Ecopath with Ecosim model of the Celtic Sea as case studies, we assessed the impacts of... |
Tipo: Text |
Palavras-chave: Balanced harvest; Gestion des pêches; Ecopath with Ecosim; Mer Celtique; Balanced Harvest; Fisheries managmeent; Ecopath with Ecosim; Celtic Sea. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00594/70652/68844.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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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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Laurec, Alain; Charuau, Anatole; Perodou, Jean-bernard; Nedelec, Daniel; Biseau, Alain; Durand, Jean-louis; Rivoalen, Jean-jacques; Dupouy, Herve; Le Louarn, G.; Leroux, L.. |
The general study, scheduled from 1984 to 1986, aims at providing a judgement about the fisheries in the Celtic Sea. This area has been chosen because it is frequented by EEC vessels with, for the time being, a large majority of French vessels. Activities there are easier to monitor than anywhere else as coastal fisheries are little developed in the area. The final product will consist of a certain number of hypotheses about the planning strategies that could be implemented in the Celtic Sea. The main idea is, firstly, to conduct analytical studies, stock by stock, in order then, to synthesize them into a model integrating the interactions between fleets in relation to their target species. A bio-economical model, deriving from the latter, will enable the... |
Tipo: Text |
Palavras-chave: Monk; Cuckoo ray; Blue whiting; Cod; Hake; Ling; Common dab; Data bases; Fishing statistics; French fisheries; Demersal fish; Nephrops; Celtic Sea; Baudroies; Raie fleurie; Julienne; Cardine; Morue; Merlu; Merlan; Base de données; Rejets; Statistiques de pêche; Pêcheries françaises; Poissons demersaux; Langoustine; Mer Celtique. |
Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/1985/rapport-3671.pdf |
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Cossa, Daniel; Cotte Krief, Marie-hélène; Mason, Robert P.; Bretaudeau-sanjuan, Jane. |
The purpose of this paper is to investigate the distribution and the relative importance of processes that affect mercury distribution in the water column at the shelf edge of the Celtic Sea, on the western European continental margin. The water column, down to 4500 m, was sampled during two cruises, one in winter 1994 and the other in June 1995, on eight stations. Total mercury concentrations ranged from 0.29 to 9.37 pM with the extreme values in the first 200 m. The highly variable concentrations in the surface layers are attributed to intense atmospheric-sea water exchange processes. The low concentrations encountered in the shelf water prelude any significant influence of continental waters in this area. In the mixed layer, biological uptake and... |
Tipo: Text |
Palavras-chave: Regeneration; Atmospheric deposition; Deep profile; Upwelling; Atlantic ocean; Celtic Sea; Shelf break; Continental margin; Mercury. |
Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/2004/publication-660.pdf |
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Day, Louise; Kopp, Dorothee; Robert, Marianne; Le Bris, Hervé. |
Human activities affect continental shelves, especially due to the harvest of living marine resources. Understanding their functioning and dynamics has become a growing concern in recent decades, especially through use of trophic modelling approaches. Studying the feeding ecology of key component species also improves this understanding by providing accurate information on trophic processes, particularly the dependence on trophic pathways. This study focuses on the trophic ecology of four large gadiforms (cod, haddock, whiting and hake) found on the continental shelf of the Celtic Sea. The study combines information on recently ingested prey (gut content analysis) and a more integrated indicator of food sources (stable isotope analysis). Two size classes... |
Tipo: Text |
Palavras-chave: Celtic Sea; Feeding; Gut content; Stable isotopes; Ontogeny; Habitat comparison. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00486/59742/62839.pdf |
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Hernvann, Pierre-yves; Gascuel, Didier; Grüss, Arnaud; Druon, Jean-noël; Kopp, Dorothee; Perez, Ilan; Piroddi, Chiara; Robert, Marianne. |
Both trophic structure and biomass flow within marine food webs are influenced by the abiotic environment and anthropogenic stressors such as fishing. The abiotic environment has a large effect on species spatial distribution patterns and productivity and, consequently, spatial co-occurrence between predators and prey, while fishing alters species abundances and food-web structure. In order to disentangle the impacts of the abiotic environment and fishing in the Celtic Sea ecosystem, we developed a spatio-temporal trophic model, specifically an Ecopath with Ecosim with Ecospace model, for the period 1985–2016. In this model, particular attention was paid to the parameterization of the responses of all trophic levels to abiotic environmental changes.... |
Tipo: Text |
Palavras-chave: Celtic Sea; Ecosystem modeling; Habitat model; Environment; Ecopath with Ecosim and Ecospace; Primary production; Fishing impact. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00662/77419/79084.pdf |
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Registros recuperados: 28 | |
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