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| Registros recuperados: 13 | |
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| Mesnil, Benoit; Guichet, Roger. |
| Due to difficulties in routinely ageing European hake, assessments of the stock have hitherto been carried out using length-based methods, and were thus restricted to pseudo-cohort analyses and long-term equilibrium projections under steady state assomptions. However, given the availability of numerical length-to-age conversion methods, it seems feasible to consider age-based assessments using the methodology of regular ICES working groups. In this paper, attempts are made to derive a time series of catches at age from the length compositions of international catches assembled by the ICES Hake Working Group for the period 1978-1990. The age-length key which is reconstructed in each year is also applied to the length composition of catches by selected... |
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| Ano: 1991 |
URL: https://archimer.ifremer.fr/doc/00394/50568/51259.pdf |
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| Guichet, Roger; Meriel-bussy, Mireille. |
| During its seasonal campaigns from July 1965 to November 1967, the Thalassa performed 190 trawl passes in the Gulf of Gascony. These catches, spread out from 35 to 300 metres between the parallels of 44"50' and 47°50' N, showed some similarities between the hake's and the blue whiting's distribution. The highest yields of one frequently match high quantities of the other and vice versa. However, this link is not so clearly demonstrated in all seasons. Moreover, we have noticed that the average weight yields of the two species increase steadily with depth (figure 1). Only sea beds of 180 metres provided different results: whereas blue whiting is in especially large numbers there, hake is less present than at neighbouring levels. It seemed worthwhile to us... |
| Tipo: Text |
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| Ano: 1970 |
URL: https://archimer.ifremer.fr/doc/1970/publication-3148.pdf |
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| Rostagno, Bernard; Violleau, Allain; Brun, Céline; Dietrich, Patrice; Fillon, Alain; Goulletquer, Philippe; Guichet, Roger; Kantin, Roger; Legay, Didier; Loubersac, Lionel; Masson, Daniel; Rocher, Gregory; Ryckaert, Mireille; Thomas, Gerard; Fichet, Denis; Guyot, Thierry; Miramand, Pierre; Pigeot, Jacques; Seguignes, Michel. |
| Cette étude, qui a rassemblé les compétences des instances de l'Etat chargées de la surveillance du milieu littoral (DDE, DDASS, IFREMER, Université de La Rochelle) a permis de dresser, à la veille de l'an 2000, un bilan de la situation environnementale du littoral de la « mer des Pertuis». Ce bilan, diversifié dans sa présentation, passe en revue les points marquants de "l'état de santé" de l'environnement, qu'il s'agisse de pollutions ciblées (chimiques, bactériologiques) ou d'autres nuisances variées. Il met en exergue les points forts et les points faibles en matière d'environnement littoral, et rappelle les efforts mis en oeuvre par les différentes administrations chargées de sa surveillance. Dans un premier temps, plus de 250 références... |
| Tipo: Text |
Palavras-chave: Environnement; Qualité eaux; Littoral; Caractéristiques physiques; Economie; Qualité chimique; Qualité bactériologique; Phycotoxines; Biodiversité; Pollution; Recommandations; Pertuis Charentais; Département Charente-Maritime. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00072/18371/15943.pdf |
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| Guichet, Roger. |
| The aim of this study is to define relationships between fishing power and vessel characteristics, and we have only considered in this paper, La Rochelle off-shore trawlers, fishing for hake. Overall length, gross registered tonnage and break horse power are the vessel characteristics taken into account. The relative fishing power bas been calculated according to Eeverton and Holt's method (1954) and for that purpose statistics set up by the Institut des Pêches Laboratory of La Rochelle in 1966-67 and 68. have been used ; only hake catches have been reckoned, and we have considered that two trawlers were fishing at the same place when they went on fishing in the same ICES sud-area, and at the same time, when the catches were sold during the same month.... |
| Tipo: Text |
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| Ano: 1970 |
URL: http://archimer.ifremer.fr/doc/00405/51695/52259.pdf |
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| Guichet, Roger. |
| In this paper the instantaneous total mortality coefficient for hake is estimated., using c.p.u.e. data of La Rochelle deep-sea trawlers from 1968 to 1970. The following two methods are used to calculate the mortality coefficient Z: the first one is obtained with the c·.p.u.e. of two successive year classes for the same year, the second is estimated with the c.p.u.e. of one year class taken in two years rurming. Everywhere, except for the West Ireland area, the total mortality seems to decrease with the age of the fish. Such a result was not observed with the "Thalassa" experimental data in the Bay of Biscay. This suggests a change in fish catchability with age. Generally, there is no great difference between the results of the. two methods. Nevertheless... |
| Tipo: Text |
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| Ano: 1973 |
URL: http://archimer.ifremer.fr/doc/00398/50910/51689.pdf |
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| Pelletier, Dominique; Beucher, Helene; Chevalier, Robert; Laurec, Alain; Alperi, J.; Pereda, P.; Guichet, Roger; Dupouy, Herve; Peronnet, Isabelle. |
| The aim of the project "rationalization of biological sampling for stock assessment of marine fisheries in the bay of Biscay" is to perform statistical methods and computer programs allowing to test prognoses and diagnoses based on estimates of fishing mortalities, recruitments, yields per recruit, and the "gain-loss" function. The project gathers the laboratories of the community working on the Bay of Biscay fisheries, namely - Santander in Spain (1. E. 0) - La Rochelle and Lorient in France (IFREMER). A descriptive study has been carried out. The prepared documents contain a description of the procedures used to collect the information, by each of the laboratories involved, on: - landings - biological samplings. More comprehensive data have been gathered... |
| Tipo: Text |
Palavras-chave: Capture; Marine biology; Fisheries; Megrim; Monk; Hake; Data collection; TAC; Bay of Biscay; Stock assessement; Sampling; Statistics; Capture; Biologie marine; Halieutique; Cardine; Baudroie; Merlu; Collecte de données; TAC; Golfe de Gascogne; Evaluation des stocks; Echantillonnage; Statistiques. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/1991/rapport-3621.pdf |
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| Guichet, Roger. |
| European hake is one of the most important commercial species of the North East Atlantic. Its biology is quite well known in spite of age reading problems. This report provides a review of the state of knowledge based on updated data, specially for parameters used in the working groups in charge of stocks assessments. The fisheries for hake are essentially sequential. In recent years fishing mortalities have been moderate and the over exploitation of the stocks is due to the excessive catches of young fish and to the fishing pattern of some fleets. The result of this inappropriate exploitation pattern is dangerous with a decrease of the spawning stock biomass and recrutrnent for the two stocks. |
| Tipo: Text |
Palavras-chave: Merlu; Nord Est Atlantique; Biologie; Exploitation; Gestion; Hake; North East Atlantic; Biology; Fisheries; Management. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00422/53327/54169.pdf |
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| Guichet, Roger; Dardignac, J.. |
| An assessment of the hake stock exploited in the Bay of Biscay and in-the Celtic Sea has been attempted. Schaefer's and Beverton-Holt's methods have been used. Due to the lack or the inadequacy of our data, a number of assumptions have been made which restrict the validity of the conclusions. Nevertheless, both methods agree in showing that a substancial increase in production (50-80 p. 100, as an order of magnitude) could be achieved by a strong reduction of fishing effort (40-60 p. 100). A still larger increase in yield p. recruit could be achieved by a mesh increase, up to 150 mm at least |
| Tipo: Text |
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| Ano: 1975 |
URL: http://archimer.ifremer.fr/doc/00397/50794/51555.pdf |
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| Registros recuperados: 13 | |
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