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Registros recuperados: 16 | |
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Guerault, Daniel; Beillois, Pierre; Desaunay, Yves. |
L'analyse des indices d'abondance obtenus à partir des données commerciales de sélections de pêcheurs, déjà réalisée pour la période 1977-84, est étendue aux années 85 et 86. l'évolution est confirmée : les pue témoignent d'une réduction d'abondance de l'ordre de 75 % en Loire et de 70 % en Vilaine, entre 1978 et 1986 et d'une stabilisation à un bas niveau. Cette analyse est complétée par la caractérisation de la production et de l'effort de pêche pour les principales catégories de pêcheurs en 85 et 86. Pour ces catégories, les indicateurs halieutiques passent - de 145 tonnes et 16 200 sorties (1985) à 112 tonnes et 13 000 sorties (1986) en Loire i - de 41 tonnes et 6 900 sorties (1985) à 53 tonnes et 7 900 sorties (1986) en Vilaine. Ces estimations... |
Tipo: Text |
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Ano: 1987 |
URL: http://archimer.ifremer.fr/doc/00135/24580/22609.pdf |
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Guerault, Daniel; Beillois, Pierre; Desaunay, Yves; Dorel, Didier. |
L'exploitation de la civelle d'anguille est d'une importancé primordiale pour un grand nombre de pêcheurs de la façade atlantique, mais les chiffres officiels de production font état d'une baisse importante de 1976 à 1984. L'étude des données commerciales enregistrées pendant cet te période fournit une série dt indices sur les variations récentes des captures, de l'effort de pêche et de la prise par unité d'effort dans l'estuaire de la Loire et de la Vilaine. L' évolution des prises par unité d'effort,' interprétées comme des indices d'abondance est la même dans les deux secteurs'. Elle permet de conclure à une très nette diminution de la ressource. |
Tipo: Text |
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Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/00135/24576/22606.pdf |
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Gilliers, Camille; Le Pape, Olivier; Desaunay, Yves; Bergeron, Jean-pierre; Schreiber, Nathalie; Guerault, Daniel; Amara, Rachid. |
Indicators of growth and condition were used to compare the habitat quality of nurseries of juvenile sole (Solea solea L.) in the Bay of Biscay, based on one survey in 2000. The four biological indicators are poorly correlated with each other, suggesting that no single measure may give an adequate description of fish health and of its habitat's quality. Growth indicators showed significant differences between northern and southern areas. Juveniles from the two southernmost nurseries, the Gironde estuary and the Pertuis Antioche, displayed significant lower otolith increment widths and mean sizes. These differences were inversely related to water temperature and unrelated to genetic or age differences, and are unlikely to be due to limiting trophic... |
Tipo: Text |
Palavras-chave: Erika oil spill; RNA/DNA; Otolith daily increment width; Essential fish habitat. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3963.pdf |
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Guerault, Daniel; Desaunay, Yves. |
Au cours de l'année 2000, deux sites d'expérimentation ont été choisis pour tenter des immersions d'huitres creuses au Nord de l'Ile d'Aix (Pertuis d'Antioche), préférés aux sites dits des Saumonards au Nord d'Oléron. Depuis longtemps, ces fonds avaient un usage unique pour la petite pêche (Geney, 1975). Le projet d'ostréiculture implique une modification quantitative (zone réservée) et qualitative (biocénose nouvelle) de l'habitat. La question se pose donc de connaitre l'état initial de l'habitat et d'envisager les modifications de ses fonctions écologiques. Les prospections halieutiques opérées par ECOHAL dans le Pertuis d'Antioche n'ont pas comme objectif l'évaluation des ressources exploitées par les différents métiers mais visent à identifier les... |
Tipo: Text |
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Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00422/53396/54265.pdf |
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Guerault, Daniel; Dorel, Didier; Desaunay, Yves. |
Expeditions undertaken using a standardised protocol between 1981 and 1996 took a census of species of commercial interest that depend on certain coastal ecosystems for at least the beginning of their life cycle. Of the 55 species censused, we identified 39 fish species, 6 crustacean species and 10 mollusc species (3 cephalopods, 5 bivalves and 2 gastropods). Some of these species are restricted to coastal systems (14 native species: 6 crustaceans and 8 molluscs) and some species whose adults are fished off the coast (41 non indigenous species: all 39 fishes and 2 cephalopods, cuttlefish and squid).The coast functions as a nursery in two ways. First, it constitutes a favourable biotope for the whole life cycle of native species. Second, for non indigenous... |
Tipo: Text |
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Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/1996/rapport-4228.pdf |
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Guerault, Daniel; Desaunay, Yves; Beillois, Pierre; Prouzet, Patrick; Martinet, Jean-pierre; Cuende, François - Xavier. |
The exploitation of amphihaline species by marine and freshwater commercial fishermen in the Loire estuary in 1989, and by marine commercial fishermen in the Adour estuary from 1985-1991 is described in this study. This fishery employs 320 fishermen and represents a commercial value of 38 million FF. This is mainly due to the exploitation of glass eel, especially in the Loire River, the landings of which have decreased alarmingly. In the Adour River, the diversity of the exploited species and the total commercial value of drift gillnet catches - on the average 43% - in this fishery are high. The landings of migratory salmonid species are high and they may attain 25% of the total commercial value. This study emphasizes the uniqueness, the socio-economic... |
Tipo: Text |
Palavras-chave: France; Loire; Adour; Atlantique; Socio économie; Biologie; Pêcherie estuarienne; Espèce amphihaline; France; Adour River; Loire River; Ocean; Atlantic; Socio economy; Biology; Estuarine fisherie; Amphihaline specie. |
Ano: 1994 |
URL: https://archimer.ifremer.fr/doc/1994/rapport-1452.pdf |
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Desaunay, Yves; Guerault, Daniel; Le Pape, Olivier; Poulard, Jean-charles. |
Several works have demonstrated trends in the distribution of fish species relative to global warming. This study investigated whether similar trends have occurred for selected flatfish species on the continental shelf of the Bay of Biscay. These species were used as indicators and changes in their Populations were studied in a coastal nursery ground,where flatfish juveniles are concentrated as well as on the entire shelf. Previous studies analysing changes in sea surface temperature for the continental shelf indicate that winter warming occurred in the 1980s and 1990s. Sixteen autumn cruises conducted since 1981 in the Bay of Vilaine nursery area and I I autumn cruises since 1987 over the entire shelf provided data on a nearly annual basis for the... |
Tipo: Text |
Palavras-chave: Bay of Biscay; Ocean warming; Spatial distribution; Flatfish. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3962.pdf |
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Claireaux, Guy; Desaunay, Yves; Akcha, Farida; Auperin, Benoît; Bocquene, Gilles; Budzinski, Hélène; Cravedi, Jean-pierre; Davoodi, Fariba; Galois, Robert; Gilliers, Camille; Goanvec, Christelle; Guerault, Daniel; Imbert, Nathalie; Mazeas, Olivier; Nonnotte, Guy; Nonnotte, Liliane; Prunet, Patrick; Sebert, Philippe; Vettier, Aurélie. |
Evaluating the ecological impact of an oil spill is a complex issue requiring coherently articulated examination of the sequence of interactions that link the cell, where contaminants exert their effects, to the ecosystem, where interactions with human activities arise. This sequence of interactions traverses the frontiers between scientific disciplines (chemistry, toxicology, physiology, and fisheries ecology). Using the common sole (Solea solea L.) as a model species for the coastal habitats polluted by the "Erika" oil spill, our research project attempted to define indices of functional integrity that characterised the consequences of fuel exposure at the different biological levels. The coupling of field observations with experimental laboratory work... |
Tipo: Text |
Palavras-chave: Physiological ecology; Common sole; Complex system approach; Oil spill. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-405.pdf |
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Le Pape, Olivier; Guerault, Daniel; Desaunay, Yves. |
This study describes the effect of an invasive mollusc, the slipper limpet Crepidula fornicata, on the distribution and abundance of young-of-the-year sole Solea solea in coastal nursery areas, based on beam-trawl surveys in the Bay of Biscay (France) over a 3 yr period (2000 to 2002). As habitat suitability for juvenile sole varies according to bathymetry and sediment structure, these factors and the density of the slipper limpet were used as descriptors in generalised linear models of habitat suitability to characterise the distribution of juvenile sole. The models were based on a delta distribution, coupling a binomial model testing for the presence of juvenile sole with a log-normal distribution for density when juveniles were known to be present.... |
Tipo: Text |
Palavras-chave: Solea solea; Nursery ground; Habitat suitability models; Crepidula fornicata; Invasive species; Bay of Biscay. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/00000/10854/7579.pdf |
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Desaunay, Yves; Guerault, Daniel. |
A beam trawl survey of the Bay of Vilaine was conducted from 1981 to 1997. Changes in the commercial fish community were analyzed by comparing the characteristics at the year and decadal scales. The community structure and nursery function of the Bay were steady during the period. However, specific richness, assiduity and distribution indices demonstrated a reduction in the second decade. The global abundance fell from 105.8 ind.ha-1 to 31.3 ind.ha-1. This trend was less marked for the external more marine stratum, which exhibited the lowest densities. The results are discussed in terms of ecological meaning of such a community, compared with the overall demersal fish community. The reasons of the decrease are questioned regarding nursery habitat, local... |
Tipo: Text |
Palavras-chave: Habitat; Survey; Bay of Vilaine; Fish community; Habitat; Suivi; Baie de Vilaine; Poissons; Peuplement. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/rapport-1288.pdf |
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Guerault, Daniel; Desaunay, Yves; Bellois, Pierre; Grellier, Patrick; Robin, Jean-paul; Robineau, Brigitte. |
A survey of the glass-eel fishery in the Loire estuary in 1987 (265 boats, 117 tons gasseel, 13733 fishing trips) showed that 16 fishery species constitute the by-catch (49,3 million individuals, mainly juveniles, among which 98 % consist in flounder, sprat and brown shrimp). The analysis of catches in space and time leads to proposaIs for Iimiting the impact during the last fishing weeks. Taking into account the naturai mortality rates of the concerned juveniles, an attempt is made to estimate the actuai impact of the glasseel fishery, after a delay. Only 10 % of the caught brown shrimps wouid have been recruited in the summer shrimp fishery. Up to 85,5 to 97,6 % of juvenile fishes would have disappeared during the following year by natural mortality. |
Tipo: Text |
Palavras-chave: Anguille; Pêcherie; Prises accessoires; Estuaire; Loire; Eel; Fishery; By catch; Estuary; Loire. |
Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/00120/23102/20951.pdf |
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Registros recuperados: 16 | |
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