Consulta: subjectFacets:"Celtic Sea"
Registros recuperados: 28
Data/hora: 13/06/2024 04:20:02

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

Etude d'une gestion optimale des pecheries de langoustines et de poissons demersaux en mer Celtique
Provedor de dados: 5
Autores: 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

Etude d'une gestion optimale des pecheries de langoustine et de poissons demerseaux en Mer Celtique. Tome 1
Provedor de dados: 5
Autores: Charuau, Anatole; Biseau, Alain.
The entire study is divised into three parts : Phase 1 - Collection of data and description of fisheries. Phase 2 - Diagnosis on the exploitation level for the main species. Phase 3 - Fleets analysis and simulation of the exploitation of the fishery. In addition to the description of the fisheries, in the first part, a very cheap method for the study of discards is described for all species and all fleets, the purpose being to use length cohorts analysis according to the JONES'method (1981). Preliminary works on monks, megrim and cuckoo ray are also presented.
Tipo: Text
Palavras-chave: Discard; Fleet; Demersal species; Celtic Sea; Rejet; Flottille; Espèce démersale; Mer Celtique.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/1989/rapport-1561.pdf

The Celtic Sea banks: an example of sand body analysis from very high-resolution seismic data
Provedor de dados: 5
Autores: Marsset, Tania; Tessier, Bernadette; Reynaud, Jean-yves; De Batist, M; Plagnol, Clara.
Very high-resolution seismic data from the Kaiser-I-Hind sand bank (southern Celtic Sea) recently highlighted the internal structure of the enigmatic Celtic Banks, which are among the deepest and largest shelf sand ridges. The main body of the bank is made up of 4 seismic/depositional units which reflect a transgressive evolution. New data on the detailed architecture of two of these units allow discussion of bank growth in terms of either (1) a channel–levee system preserved both by lateral migration and aggradation of the channels, or (2) a package of large offshore tidal sediment bodies (bar chains and/or giant dunes). Careful geometrical observations of seismic discontinuities make the second hypothesis more likely. The unit architecture is analysed in...
Tipo: Text
Palavras-chave: Sand bank; Tidal dynamics; Dunes; Channels; Celtic Sea; Very high-resolution seismics.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/00061/17192/14693.pdf

Le Balanced Harvest est-il une bonne idée ? Une approche par modélisation écosystémique pour reconstruire les pêcheries et la structure trophique en mer Celtique.
Provedor de dados: 5
Autores: 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

Trophic ecology of large gadiforms in the food web of a continental shelf ecosystem
Provedor de dados: 5
Autores: 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

Spatial distribution of discards in mixed fisheries: species trade-offs, potential spatial avoidance and national contrasts
Provedor de dados: 5
Autores: Robert, Marianne; Calderwood, Julia; Radford, Zachary; Catchpole, Tom; Reid, David G.; Pawlowski, Lionel.
Since 2015, the European Union gradually implemented the landing obligation (LO). This prohibits at-sea discarding of species under total allowable catch management. Spatiotemporal avoidance strategies and increasing fishing gear selectivity are two complementary levers that could help fishers in reducing the amount of discards. The objective of this paper is to analyse discarding practices of demersal mixed fisheries in the central part of the Celtic Sea to inform on potential spatial avoidance strategies of unwanted catches in a multi-species context. This study provides the first international and fine scale discard maps based on combined observer at-sea data from Ireland, France and the UK, the main countries fishing in the area. Using a suite of...
Tipo: Text
Palavras-chave: Fisheries management; Landing obligation; Discards; Mixed fisheries; Celtic Sea.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00515/62641/67029.pdf

Programme d Orientation Pluriannuel concernant une action commune de restructuration, de modernisation et de développement du secteur de la peche
Provedor de dados: 5
Autores: Minet, Jean-pierre; Biseau, Alain; Charuau, Anatole; Dupouy, Herve; Durand, Jean-louis; Perodou, Jean-bernard.
Answering a need of the Office of Regional Marine Affairs of Brittany, the "fisheries" laboratory of the Ifremer in Lorient provides synthesis elements about the status of the stocks of the main species exploited in the Bay of Biscay, Celtic Sea and Western Ireland in 1983. It provides information about the fishing capacity according to the different jobs done and compares two fleets from South-Brittany: Lorient and Concarneau. This report will have to be completed by the laboratories of Roscoff for activities in North-Brittany and of la Rochelle for activities in the Bay of Biscay.
Tipo: Text
Palavras-chave: Fishing fleet; Concarneau; Lorient; Fishing resources; West Ireland; Celtic Sea; Bay of Biscay; Brittany; Fishing; Flottille de pêche; Concarneau; Lorient; Ressource de pêche; Ouest Irlande; Mer Celtique; Golfe de Gascogne; Bretagne; Pêche.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/rapport-3635.pdf

The French experience in sampling discards at sea in the European waters
Provedor de dados: 5
Autores: Tetard, Alain; Gaudou, Olivier; Lespagnol, Patrick; Peronnet, Isabelle; Rochet, Marie-joelle; Vigneau, Joel.
This study covered a one year period using onboard observers (117 days at sea). The aim was to sample "métiers" known for their discarding side effects: fixed netting, inshore and offshore trawling. The objectives were (i) the collection of information on the demographic structure of the catches for the main exploited species and (ii) the identification of factors explaining discards, in order to find relevant management measures
Tipo: Text
Palavras-chave: Celtic Sea; French trawlers; Sampling; Observers; Discard; Metiers; Mer Celtique; Chalutiers français; Échantillonnage; Observateurs; Rejets; Metiers.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/rapport-6129.pdf

Projet CELSELEC. Amélioration de la sélectivité des chalutiers hauturiers en mer Celtique
Provedor de dados: 5
Autores: 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

Etude d'une gestion optimale des pecheries de langoustine et de poissons demerseaux en mer Celtique. Tome 2
Provedor de dados: 5
Autores: Charuau, Anatole; Biseau, Alain.
The theory of the evaluation of discards applied in phase 1 to the main eight species is described. Then, for each one, the biological parameters are calculated and diagnosis based on length cohorts analysis JONES (1981) are proposed The gadoids, whiting and cod, are heavily exploited and the catches are always recruitment dependant. The bottom species (monks, megrim, rays and Nephrops) are fully exploited or lightlhy over - exploited. Using the fisheries statistics of the data basis about the Celtic Sea, a first classification of fleets is proposed with the individual fishing powers.
Tipo: Text
Palavras-chave: Puissances de pêche; Rejet; Espèce démersale; Mer Celtique; Fishing power; Discard; Demersal species; Celtic Sea.
Ano: 1989
URL: https://archimer.ifremer.fr/doc/1989/rapport-1562.pdf

Estimation des rejets de peche des chalutiers français en mer Celtique
Provedor de dados: 5
Autores: Rochet, Marie-joelle; Trenkel, Verena; Peronnet, Isabelle.
Discards of the French trawler fleet operating in the Celtic Sea in 1997 were studied. Twenty-six trips, representing 0.8% of the total fishing effort, were sampled. This fleet consists of three métiers, benthic trawlers, demersal trawlers and Nephrops trawlers. The fleet discarded an estimated 30,000 tons of animals in 1997, while landing 63,000 tons. The total quantity discarded did not differ among métiers, but the species composition of discards did. Benthic trawlers discarded mainly by-catch species, whereas demersal and Nephrops trawlers discarded primarily their target species. Whiting, megrim, Nephrops and hake were discarded in larger numbers than landed. Hence discards should probably be taken into account in catch-based assessments. However,...
Tipo: Text
Palavras-chave: Espèce non commerciale; Langoustine; Baudroie; Poisson plat; Gadidé; Mer celtique; Echantillonnage des rejets; Non commercial species; Nephrop; Anglerfish; Flatfish; Gadoid; Trawler; Celtic Sea; Discard sampling.
Ano: 2001
URL: https://archimer.ifremer.fr/doc/2001/rapport-1575.pdf

Projected impacts of warming seas on commercially fished species at a biogeographic boundary of the European continental shelf
Provedor de dados: 5
Autores: Maltby, Katherine M.; Rutterford, Louise A.; Tinker, Jonathan; Genner, Martin J.; Simpson, Stephen D.; Punt, Andre.
Projecting the future effects of climate change on marine fished populations can help prepare the fishing industry and management systems for resulting ecological, social and economic changes. Generating projections using multiple climate scenarios can provide valuable insights for fisheries stakeholders regarding uncertainty arising from future climate data. Using a range of climate projections based on the Intergovernmental Panel on Climate Change A1B, RCP4.5 and RCP8.5 climate scenarios, we modelled abundance of eight commercially important bottom dwelling fish species across the Celtic Sea, English Channel and southern North Sea through the 21st century. This region spans a faunal boundary between cooler northern waters and warmer southern waters,...
Tipo: Text
Palavras-chave: Celtic Sea; Climate change; English Channel; Fish; Fisheries; North Sea; Regional projections; Uncertainty.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00643/75490/76341.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

Etude d'une gestion optimale des pecheries de langoustines et de poissons demersaux en mer Celtique (phase 1)
Provedor de dados: 5
Autores: Biseau, Alain; Noel, Philippe; Ottenheimer De Gail, G.; Rivoalen, Jean-jacques.
This study of the demersal and benthic fisheries in the Celtic Sea is the logical continuation of the works conducted on the scampi fisheries since 1978. The program of the first phase of the study consists of 1 - A description of fisheries in the Celtic Sea. 2 – An assessment of the rejection of the marketable species in each fishery, with a special mention for fish fisheries. 3 – The constitution a computerized database including international fishing statistics since 1980. 4 – The sampling of the unloading of seven main species or groups of species: - cod and whiting, already sampled (length and age) regularly since 1978 in order to provide data to the CIEM workgroup. "Irish Sea – Bristol Channel", - scampi, sampled since 1980 in the scope of the CIEM...
Tipo: Text
Palavras-chave: Cartography; Ray; Monk; Common dab; Hake; Demersal fish; Nephrops; Celtic Sea; Cartographie; Rejets; Raie; Baudroie; Cardine; Merlu; Poissons demersaux; Langoustines; Mer Celtique.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/rapport-3672.pdf

Total mercury in the water column near the shelf edge of the European continental margin
Provedor de dados: 5
Autores: 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

Age and Growth of the lemon sole (Microstomus kitt) in the Celtic Sea and the North Sea
Provedor de dados: 5
Autores: Mahe, Kelig; Elleboode, Romain; Persohn, Cecile; Dufour, Jean-louis.
Age and growth of lemon sole (Microstomus kitt) were determined from 115 specimens collected in the Celtic Sea and in the North Sea in 2006 and 2007. Total length is ranged from 11 to 44 cm, while total weight varied between 12 and 1040 g. Age estimation was based on otoliths readings. The oldest male and female were estimated to be 9 years old. The length–weight relationships parameters for lemon sole in the Celtic Sea and in the North Sea were W=0.0043*TL3.2860 and W=0.0062*TL3.1505 respectively. Weight including both sexes increased with positive allometric growth. The von Bertalanffy growth equation in the North Sea was fitted on the basis of mean length-at-age data resulting in parameters values of TL∞ = 36.44 cm (S.E. = 0.484), K = 0.187 /y (S.E. =...
Tipo: Text
Palavras-chave: Lemon sole; Growth; Von Bertalanffy; Celtic Sea; North Sea.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00019/13024/10002.pdf

Environment outweighs the effects of fishing in regulating demersal community structure in an exploited marine ecosystem
Provedor de dados: 5
Autores: Mérillet, Laurene; Kopp, Dorothee; Robert, Marianne; Mouchet, Maud; Pavoine, Sandrine.
Global climate change has already caused bottom temperatures of coastal marine ecosystems to increase worldwide. These ecosystems face many pressures, of which fishing is one of the most important. While consequences of global warming on commercial species are studied extensively, the importance of the increase in bottom temperature and of variation in fishing effort is more rarely considered together in these exploited ecosystems. Using a 17‐year time series from an international bottom‐trawl survey, we investigated co‐variations of an entire demersal ecosystem (101 taxa) with the environment in the Celtic Sea. Our results showed that over the past two decades, biotic communities in the Celtic Sea were likely controlled more by environmental variables...
Tipo: Text
Palavras-chave: Bottom trawl survey; Celtic Sea; Fishing effort; Marine resources; Spatio-temporal dynamics; Stability; STATICO multivariate analysis.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00599/71150/69470.pdf

Alimentation du merlan Merlangius merlangus L. en Mer Celtique
Provedor de dados: 5
Autores: Du Buit, Marie-henriette; Merlina, Frédéric.
The importance of predation by the whiting (Merlangius merlangus ) from the Celtic Sea has been studied by analysis of stomach contents. Eight hundred and thirteen whitings have been examined during 1984-1986 period. Fish food totalizes 97% of food. It is chiefly a swimming species: no cannibalism has been observed. The daily food index varies between 2 and 4% according to the length and the annual consumption on fishes of nominal catches (11230 t for 1983) would reach 135,000 t corresponding to species already fished for human consumption and the fish meal industry.
Tipo: Text
Palavras-chave: Celtic Sea; ANE; Gadidae; Pisces; Merlangius merlangus; Predator control; Stomach content; Feed composition; Feeding.
Ano: 1985
URL: http://archimer.ifremer.fr/doc/1985/publication-1744.pdf

Evidence of a relationship between weight and total length of marine fish in the North-eastern Atlantic Ocean: physiological, spatial and temporal variations
Provedor de dados: 5
Autores: 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

The Celtic Sea Through Time and Space: Ecosystem Modeling to Unravel Fishing and Climate Change Impacts on Food-Web Structure and Dynamics
Provedor de dados: 5
Autores: 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

Concentrations of mercury and other trace elements in two offshore skates: sandy ray Leucoraja circularis and shagreen ray L. fullonica
Provedor de dados: 5
Autores: Nicolaus, E. E. Manuel; Barry, Jon; Bolam, Thi P. C.; Lorance, Pascal; Marandel, Florianne; Phillips, Sophy R. Mccully; Neville, Suzanna; Ellis, Jim R.
Trace metal concentrations in muscle and liver tissues from two offshore species of skate were examined. Concentrations of mercury in muscle of Leucoraja circularis (n = 20; 23–110.5 cm total length, 157–490 m water depth) and L. fullonica (n = 24; 28.5–100 cm total length, 130–426 m water depth) were 0.02–1.8 and 0.04–0.61 mg kg− 1, respectively. Concentrations of both As and Hg increased with total length. Only the largest specimen had a concentration of Hg in muscle &gt; 1.0 mg kg− 1. Data were limited for specimens &gt; 90 cm long, and further studies on contaminants in larger-bodied skates could usefully be undertaken.
Tipo: Text
Palavras-chave: Trace metals; Sandy ray; Shagreen ray; Bay of Biscay; Celtic Sea.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00397/50829/51592.pdf

Trophic models: What do we learn about Celtic Sea and Bay of Biscay ecosystems?
Provedor de dados: 5
Autores: Moullec, Fabien; Gascuel, Didier; Bentorcha, Karim; Guenette, Sylvie; Robert, Marianne.
Trophic models are key tools to go beyond the single-species approaches used in stock assessments to adopt a more holistic view and implement the Ecosystem Approach to Fisheries Management (EAFM). This study aims to: (i) analyse the trophic functioning of the Celtic Sea and the Bay of Biscay, (ii) investigate ecosystem changes over the 1980–2013 period and, (iii) explore the response to management measures at the food web scale. Ecopath models were built for each ecosystem for years 1980 and 2013, and Ecosim models were fitted to time series data of biomass and catches. EcoTroph diagnosis showed that in both ecosystems, fishing pressure focuses on high trophic levels (TLs) and, to a lesser extent, on intermediate TLs. However, the interplay between local...
Tipo: Text
Palavras-chave: Ecosystem Approach to Fisheries Management (EAFM); Bay of Biscay; Celtic Sea; Ecopath with Ecosim; EcoTroph; Trophic indicators.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00377/48771/49169.pdf

Spatial and temporal structure of predator-prey relationships in the Celtic Sea fish community
Provedor de dados: 5
Autores: 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

Disentangling the effects of capture efficiency and population abundance on catch data using random effects models
Provedor de dados: 5
Autores: Trenkel, Verena; Skaug, Hans.
We propose a random effects model for disentangling population abundance and capture efficiency effects on bottom-trawl catches. The spatial distribution of individual fish is assumed random leading to a Poisson distribution for the number of individuals in the trawl path (no schooling). Capture efficiency, i.e. the proportion of individuals in the trawl path being retained by the gear, is modelled as a random variable. We propose model extensions that include the effects of body size on haul efficiency. We applied the models to several species from the Celtic Sea groundfish community based on small-scale repetitive hauls. The resulting abundance estimates allowed us to study population abundance ratios; the estimated capture efficiencies were comparable...
Tipo: Text
Palavras-chave: Trawl survey; Poisson distribution; Celtic Sea; Catchability; Abundance.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-828.pdf

Exploring the impacts of fishing and environment on the Celtic Sea ecosystem since 1950
Provedor de dados: 5
Autores: Hernvann, Pierre-yves; Gascuel, Didier.
Analyzing the long-term changes in ecosystems and disentangling the influence of overfishing and environment require historical data integration. Fisheries-independent data are available only since the mid-1980s in the Celtic Sea and thus provide a short-term and truncated vision of fishing impacts. We conducted a catch-based study over the 1950–2015 period. We successively (i) reconstituted catch time-series, including unreported catch estimates, and studied them through a trophic-spectrum approach and ecosystem indicators based on trophic level, size and species diversity; (ii) estimated biomass trends of the main Celtic Sea target species from catch and effort time-series, using production models that detect potential shifts in productivity; and (iii)...
Tipo: Text
Palavras-chave: Fishing impact; Celtic Sea; Catch reconstruction; Biomass production model; Ecosystem regime shifts; Trophic cascade; Fish productivity.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00600/71241/73090.pdf

Analyse des puissances de pêche des chalutiers et des abondances apparentes des espèces de la pêcherie démersale de mer celtique
Provedor de dados: 5
Autores: Perodou, Jean-bernard.
Fishing power analysis leads to determine a typology of fleet which depends on target species. Three factors are examined : port of origin, engine power and type of trawl. Specific abundance index analysis leads to determine a diagram of principal stages of vital cycle : juvenile, reproductive adult and recovery adult. Then calculs are made in value for all species combined : we obtain thus an economical index by location and season.
Tipo: Text
Palavras-chave: Mer Celtique; Indice économique; Abondance apparente; Typologie des flottille; Puissance de pêche; Celtic Sea; Economical index; Abundance index; Fleet typology; Fishing power.
Ano: 1988
URL: https://archimer.ifremer.fr/doc/1988/rapport-1573.pdf

Does diet in Celtic Sea fishes reflect prey availability?
Provedor de dados: 5
Autores: Pinnegar, J; Trenkel, Verena; Tidd, A; Dawson, W; Du Buit, M.
Feeding preferences of Celtic Sea fishes were investigated using a database of stomach content records, collected between 1977 and 1994. The diet of cod Gadus morhua, hake Merluccius merluccius, megrim Lepidorhombus whiffiagonis, whiting Merlangius merlangus and saithe Pollachius virens changed markedly as the animals grew larger, and although large predators generally chose larger bodied prey, the variability of prey sizes consumed also increased. Large predators continued to select small, low value, benthic prey (e.g. Callionymus spp. and Trisopterus spp.) which were easier to catch, rather than larger, more energy lucrative pelagic prey (e.g. mackerel Scomber scombrus), even though these pelagic prey-fishes were nearly always available and were often...
Tipo: Text
Palavras-chave: Stomach contents; Preference; Diet; Celtic Sea; Availability.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/publication-607.pdf