Stock characteristics of Atlantic salmon

The general characteristics of the main salmon (Salmo salar L.) stocks in the Massif armoricain (Brittany and Lower Normandy), in the Loire-Allier and in the Adour-Gaves-Nive have been summarized. Due to the poor quality of the previous fishing statistics, there is no clear picture of the historical evolution of the salmon stock. However, a dramatic decrease in the endemic range of Atlantic salmon in France can be shown since the mid-18th century and more particularly during the last 50 years. The lack of precise informations describing the size of the catches and the levels of exploitation at sea and in the estuaries make it impossible to estimate the impact that exploitation has led on the evolution of salmon stocks. The mean age of salmon in freshwater ranges from 1 to 1.5 years. The Loire-Allier basin is characterized by a relatively high proportion of large salmon (3 fish) in the rod catches. Fish native to Brittany and Lower-Normandy (Massif armoricain) have lover growth rates than those from the Loire-Allier and Adour-Gaves-Nice Basins. A greater proportion of the early grilse stocks (migration May-July) are males than compared with fish running later. The sex ratio of the multi-sea-winter salmon is biased towards females

Modèles loglinéaires pour l'étude des associations entre captures par unité d'effort et variables hydroclimatiques

In this paper we study associations between categorical variables. We present an approach based on loglinear modelling. A better knowledge of the influence of the intensity of tidal coefficient (cm) and of the rate of river flow (df) on catch per unit effort (cpue) of allis shad (Alosa alosa) was obtained. Analysis performed indicated that an increase of catch per unit effort is proportionally associated with the increase in the tidal coefficient. We also noted the influence of the rate of flow.Dans cet article, nous étudions les associations entre variables qualitatives. Nous présentons une approche basée sur l'utilisation du modèle loglinéaire. Appliqués aux associations entre captures par unité d'effort (cpue) d'aloses (Alosa alosa), coefficient de marée (cm) et débit fluvial (df), différents modèles mettent en évidence que les captures par unité d'effort augmentent proportionnellement à la valeur du coefficient de marée et qu'elles ont des évolutions conjointes moins structurées avec le débit fluvial

La vie marine du saumon atlantique dans son aire geographique

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Marine Renewable Energies: Main Legal Issues

International audience; The development of renewable marine energies has its origin in the United Nations' Framework Convention on Climate Change, adopted on 9 May 1992, and in the additional protocol, adopted in 1997 in Kyoto. Although, for many years, the French legal system did not consider the specificities of ocean renewable energies, the French government now seems to have become aware of the importance of establishing an adapted legal framework. The boom of marine renewable energies is the result of proactive policies from a French nation that seeks to meet its international and European commitments. The French policy makes use of legal instruments that ensure programming and planning. The economic activities in the field of marine renewable energies make up a market to which access is regulated. This requires administrative procedures which are as varied as they are complex. © ISTE Ltd 2015. All rights reserved

L'anchois du golfe de Gascogne - Généralités et campagne de pêche en 1993

The anchovy, Engraulis encrasicolus L. population in the Bay of Biscay, is described in context with other Engraulidae populations in the world. Mean landings are provided for six different species from 1974 to 1992. The great variations in the abundance (up to 200 %) of these populations, in relation to upwelling and environmental parameters are also discussed. Historical changes in the French and Spanish fleet fishing for anchovy are highlighted since 1950. The main events in the development of these fisheries are detailed. The total number ofboats in the French fleet have increased from 1987-1993 whereas the number of seiners in the Spanish fleet in that peri ad remained stable since 1980. The third part of this report describes the French fishery for anchovy, the main fishing areas and associated effort, landings by month and biological characteristics.Les caractéristiques de l'anchois du golfe de Gascogne (Engrau/is encrasicolus L.) sont décrites ainsi que celles des principales populations d'anchois dans le Monde. Les débarquements moyens ainsi que leurs variations sont donnés pour la période allant de 1974 à 1992. Cette synthèse met en lumière les fortes variations des productions pour l'ensemble des stocks concernés (jusqu'à 200%). L'effet des conditions du milieu sur ces fluctuations d'abondance est discutée. Dans une seconde partie, l'évolution des flottilles françaises et espagnoles est analysée depuis le milieu de ce siècle. Les principaux évènements qui ont jalonné les pêcheries d'anchois du golfe de Gascogne depuis les années cinquante sont mentionnés. On peut noter, en particulier, depuis les années quatre-vingts une arrivée importante de chalutiers pélagiques du côté français. Du côté espagnol, cet engin n'est pas autorisé, seule la pêche à la senne est pratiquée. La troisième partie du rapport fait le point sur la campagne de pêche française en 1993. Elle détaille les caractéristiques des flotilles, les zones de pêche fréquentées, la répartition des débarquements dans le temps et leurs caractéristiques

Towards the implementation of an integrated approach to fisheries resources management in Ifremer, France

Implementing the Ecosystem Approach to Fisheries is a demanding exercise even though a more or less sophisticated approach might be adopted depending on the fishery or problem concerned and on the capacity available to deal with it. In France, DEMOSTEM, a programme of Ifremer was established to try to practically apply the EAF principles across the high diversity of situations existing in the country. The article summarizes very briefly the lessons learned through this programme implementation and some of the key findings and outcomes. In conclusion, it offers some perspectives on the whole process

Numerical analysis of scale morphology to discriminate between atlantic salmon stocks

The use of an image analysis microsystem with a specially developed software enabled scale image processing, outline extraction and computation of features which are not available in the conventional approach of scale analysis. Those parameters (shape factors, moment invariants and elliptic Fourier coefficients) were introduced into a discriminant analysis process to test their usefulness in stock identification. The method was applied to European stocks originating from Norway (Etne river) and France (Elorn river). The low misclassification rate obtained indicates that this approach is particularly promising.L'utilisation d'un microsystème d'analyse d'image et d'un logiciel développé pour cette application permet l'acquisition et le traitement d'images d'écailles, l'extraction de leur contour et le calcul d'attributs non accessibles par les méthodes classiques d'analyse scalimétrique. Le pouvoir discriminant de ces attributs (facteurs de forme, moments invariants, coefficients elliptiques de Fourier) est ensuite évalué. La méthode est appliquée à deux stocks originaires de rivières européennes, l'Etne (Norvège) et l'Elorn (France). Le faible taux d'erreur de classification obtenu permet de conclure à l'intérêt de cette approche

Fonctionnement d'une population de saumon Atlantique du sud de l'aire de répartition

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