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| Registros recuperados: 18 | |
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| Laurec, Alain. |
| An analysis of the fishing power concepts leads to a distinction between local fishing power (at a given location). and overall fishing power. Overall fishing power takes into account the ability to detect and quickly exploit rich areas. In order to estimate local fishing power it is necessary to compare the catches of different ships operating in neighbouring areas. Such a comparison performed on two ships will give an estimate of their relative fishing powers. The closer the two ships are, the more reliable will be the estimate. A weighting function must be used, and this function is related to the spatial heterogeneity of the fish density. Such a function is provided by the variogram as defined by Matheron (1965). [NOT CONTROLLED OCR] |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1977 |
URL: http://archimer.ifremer.fr/doc/1977/publication-5169.pdf |
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| Laurec, Alain; Blanc, François. |
| Continuous sampling is now widely used in oceanography and requires new tools for data processing. The theory of stochastic processes and especially spectral analysis offers powerful ones. We are dealing in this paper with bivariate time series : temperature and salinity were continuously measured during the CINECA-CHARCOT II cruise, in the upwelling area of North-West Africa. The record has been splitted into three parts corresponding to straight lines. Those time series have been prewhitened using the first finite difference filter, spectra and cross-spectra were smoothed using the Parzen window. Power spectra reveals obvious peaks. Coherencies are higher in low frequencies. The basic phenomena, mixing due to the upwelling (transfer functions can be... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1974 |
URL: http://archimer.ifremer.fr/doc/1974/publication-5153.pdf |
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| Laurec, Alain; Le Gall, Jean-yves. |
| Two different statistical techniques of analysis have been worked out in order to analyse the components of available data of catch per unit of effort (C. P. U. E. by month), used as an abundance index, for the Atlantic Japanese tuna longline fishery harvesting north-southern stocks of albacore (Thunnus alalunga). These techniques have been developed in order to estimate different components of this abundance index, such as yearly trend, a seasonal component, fishing effort impact, and unknown residual component. Both techniques combine these components either in an additive model or multiplicative one and allow to assign to the trend a continuous or discrete (stepwise) shape. The first technique is simple, it is called " moving average " and applies... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1975 |
URL: http://archimer.ifremer.fr/doc/1975/publication-5085.pdf |
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| Buestel, Dominique; Nicolas, R.; Morize, E.; Rohan, R.; Latrouite, Daniel; Le Borgne, Y.; Cochard, Jean-claude; Flassch, Jean-pierre; Uno, Yutaka; Audouin, Jacques; Legall, J.y.; Jezequel, M.; Lorec, J.; Henocque, Yves; Reveche, C.; Girin, Michel; Laurec, Alain; Herry, P.. |
| L'aquaculture extensive et le repeuplement sont deux modes d'exploitation des ressources halieutiques qui ne font appel, une fois les juvéniles produits, ni à un apport de nourriture artificielle, ni à un contrôle continu de la part de l'exploitant, mais dépendent par contre de la productivité du milieu marin, Cette approche repose sur l'idée que le principal facteur limitant d'une population naturelle est le faible nombre de survivants après les premiers stades, et que l'on peut par alevinage, aménagement du milieu ou autres techniques, augmenter la production d'une espèce exploitable, Le but de ces journées d'étude est de faire le point des connaissances sur ces sujets, à l'intention des scientifiques mais aussi des utilisateurs, Il a paru souhaitable de... |
| Tipo: Text |
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| Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00018/12941/9907.pdf |
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| Blanc, François; Laurec, Alain. |
| In an answer to FRONTIER (1975)à the authors try to define their philosophy about data processing by mathematical methods in marine ecology. They point out that the ecologist may not expect miracles from these methods, but that, correctly used, they provide an especially heuristic tool if not a thaumaturgic one. They first discuss the exact suggest the main features of what should be any correct strategg in data processing, and try to give FRONTIER an answer on certain precise topics. [NOT CONTROLLED OCR] |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1976 |
URL: http://archimer.ifremer.fr/doc/1976/publication-5111.pdf |
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| Boucher, Jean; Laurec, Alain; Samain, Jean-francois; Smith, S. L.. |
| The amylase and trypsin activity of the most important zooplankton species has been measured in the upwelling zone of the Spanish Sahara during the "Gibraltar ecophysiological cruise" of the oceanographic vessel Jean Charcot. The analysis of the results was carried out for the double purpose of demonstrating the regulation by the nutrition of the activities of digestive enzymes and utilizing these results to study the feeding behavior under the natural environmental conditions of an ecosystem. With regard to its biological significance, the influence of the quality and quantity of food available has been demonstrated by a bouble experimental approach followed by a statistical one. Significant correlations were found between the specific amylase activity... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1975 |
URL: http://archimer.ifremer.fr/doc/1975/publication-5105.pdf |
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| Le Gall, Jean-yves; Laurec, Alain; Bard, François-xavier; Dao, Jean-claude. |
| Cette étude intègre simultanément les données de la pêcherie palangrière de l'Atlantique Nord Central (prises annuelles en nombre par classes d'âge à partir des échantillonnages de la pêcherie japonaise) et les données de la pêcherie de surface franco-espagnole de l'Atlantique Nord-Est (prises annuelles en nombre par classes d'âge à partir des échantillonnages de la pêcherie française). L'analyse des cohortes sur ces données conduit à des estimations de Fi et de tailles de cohortes au recrutement et la sortie de la pêche de surface, puis au recrutement de la pêcherie palangrière. Le recoupement et le recouvrement de ces résultats permettent de construire une série de Fi et, à partir des données de Mi extraites d'autres études, d'appliquer les modèles... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1974 |
URL: http://archimer.ifremer.fr/doc/1974/publication-5469.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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| Chardy, Pierre; Derrien, Elizabeth; Jezequel, Michele; Laurec, Alain; De La Salle, Patrice. |
| The study of a first annual hydrobiological cycle on the site of Flamanville was carried out through 19 campaigns conducted between July 76 and June 77. Twelve of them are considered as "heavy" and took place on the following dates: July 8th, 76; August 6th, September 4th, October 3rd, November 3rd, December 16th, January 5th, 77; February 2nd, March 3rd, April 14th, May 10th and May 24th. Seven campaigns consist only in one sample July 23rd, 76; August 21st, September 16th, November 19th, January 19th, 77; February 17th and June 16th. However, some variables which had not been measured during these "light" missions have not been taken into account for the analysis. A first global analysis groups together the first ten campaigns (in May, the nutritive... |
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| Ano: 1977 |
URL: http://archimer.ifremer.fr/doc/00355/46643/46472.pdf |
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| Chardy, Pierre; De La Salle, Patrice; Derrien, Elizabeth; Jezequel, Michele; Laurec, Alain. |
| Dans le cadre des études écologiques de "projet" EDF, l'exploitation mathématique des données a pour objectif immédiat : - d'optimiser l'échantillonnage par une meilleure connaissance de la variabilité dans le temps et dans l'espace des phénomènes étudiés, - de résumer une information volumineuse et multidimensionnelle par une structure simple traduisant les caractéristiques écologiques essentielles du site - de dégager les paramètres et les espèces responsables de la structure mise en évidence dans la perspective du suivi écologique. |
| Tipo: Text |
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| Ano: 1976 |
URL: http://archimer.ifremer.fr/doc/00006/11735/8409.pdf |
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| Antoine, Loïc; Arzel, Pierre; Laurec, Alain; Morize, Eric. |
| The growth of the scallop ( Pecten maximus L.) has been studied in several stocks along the french coast . The growth in height has been first described by the Von Bertalanffy growth curve, and the paramete rs (especially K and Loo) compared between the different stocks. An attempt has been made to study local (inside a stock) spatial heterogeneities, as well as variations from year to year. Finally a modification of the Von Bertalanffy growth curve is suggested, whick takes into account seasonnal variations in the growth rate. |
| Tipo: Text |
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| Ano: 1976 |
URL: http://archimer.ifremer.fr/doc/00247/35868/34388.pdf |
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| Le Gall, Jean-yves; Laurec, Alain; Chardy, Pierre. |
| The study is based on available data of previous descriptive works dealing with the diagnostic characters of genus Thunnus seven species ; multivariable technics analysis are used for classification and ordination in order to examine the validity of specific groups usually admitted by classical technics of taxonomy analysis. Respective values of visceral, squelettic and meristic characters are reviewed. Building of a cladogram (by cladistic analysis) based on the coding of 12 characters with evolutive processes meaning leads to submit some hypothesis on phylogenetic relationships between species and group of species recognized progress of the present study. [NOT CONTROLLED OCR] |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1975 |
URL: http://archimer.ifremer.fr/doc/1975/publication-5474.pdf |
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| Drogou, Mickael; Laurec, Alain; Bissery, Claire; Mahevas, Stephanie; Demaneche, Sebastien; Begot, Eric; Weiss, Jerome; De Pontual, Helene; Le Goff, Ronan. |
| La décroissance des rendements de capture professionnelle de bar européen Dicentrarchus labrax à partir des années 2010-2011 a amené la DPMA à demander à l’Ifremer de proposer un programme de recherche visant à mieux connaitre la biologie de l’espèce et à acquérir des données et connaissances permettant d’envisager sa gestion. Parmi les actions de recherche identifiées comme prioritaires, l’action « Données professionnelles » a compris deux grands volets : - utilisation des données de captures professionnelles françaises afin de produire des indices annuels d’abondance en bars adultes, - acquisition de données biologiques (maturité sexuelle principalement et courbe de croissance) sur le bar dans le golfe de Gascogne |
| Tipo: Text |
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| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00429/54044/55428.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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| Registros recuperados: 18 | |
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