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International audience; Ciguatoxins (CTXs) are lipid-soluble polyether compounds produced by dinoflagellates from the genus Gambierdiscus spp. typically found in tropical and subtropical zones. This endemic area is however rapidly expanding due to environmental perturbations, and both toxic Gambierdiscus spp. and ciguatoxic fishes have been recently identified in the North Atlantic Ocean (Madeira and Canary islands) and Mediterranean Sea. Ciguatoxins bind to Voltage Gated Sodium Channels on the membranes of sensory neurons, causing Ciguatera Fish Poisoning (CFP) in humans, a disease characterized by a complex array of gastrointestinal, neurological, neuropsychological, and cardiovascular symptoms. Although CFP is the most frequently reported non bacterial food-borne poisoning worldwide, there is still no simple and quick way of detecting CTXs in contaminated samples. In the prospect to engineer rapid and easy-to-use CTXs live cells-based tests, we have studied the effects of CTXs on the yeast Saccharomyces cerevisiae, a unicellular model which displays a remarkable conservation of cellular signalling pathways with higher eukaryotes. Taking advantage of this high level of conservation, yeast strains have been genetically modified to encode specific transcriptional reporters responding to CTXs exposure. These yeast strains were further exposed to different concentrations of either purified CTX or micro-algal extracts containing CTXs. Our data establish that CTXs are not cytotoxic to yeast cells even at concentrations as high as 1μM, and cause an increase in the level of free intracellular calcium in yeast cells. Concomitantly, a dose-dependent activation of the calcineurin signalling pathway is observed, as assessed by measuring the activity of specific transcriptional reporters in the engineered yeast strains. These findings offer promising prospects regarding the potential development of a yeast cells-based test that could supplement or, in some instances, replace current methods for the routine detection of CTXs in seafood products.

Poster; International audience; Langlois et al. (2012; 2014a) proposed characterization factors (CF) for fish biotic resource extraction impact assessment at the species level. This paper is an improvement of this approach. In the present work, the CF depends on the Maximum Sustainability Yield (MSY), weighted by the ratio of the current total fishing effort to the fishing effort at the MSY value. Because this ratio often cannot be computed from current databases, it is here obtained from the ratio of total catches to MSY and roots of the parabola linking catches to fishing effort. The new version of the CF is proposed for 125 fish stocks. This work allows assessment of fisheries in the LCA formalism. It contributes to a better representation of the depletion of biotic resources.

The Ifremer Centre of Brest has hosted the 15th Annual Conference of the European Association of Fisheries Economists. The Conference has gathered more than 80 participants. Presentations have addressed very diverse topics relating to the economic aspects of marine resources and environment uses and management, of industries and markets. The debates on the 2002 Common Fisheries Policy Reform, addressed in a plenary session, have shown the signif icance of fisheries management for the economic research. A number of presentations and a round table have focused on seafood products chain, consumption and markets. These topics draw more and more European economists’ attention., Le Centre Ifremer de Brest a hébergé la 15e conférence annuelle de l’Association européenne des économistes des pêches. La conférence a rassemblé plus de 80 participants. Les communications ont traité de thèmes très divers touchant aux aspects économiques des usages et de la gestion des ressources et de l’environnement marin, des industries et des marchés. Les débats sur la réforme de la politique commune de la pêche 2002, abordée en plénière, ont montré l’importance de la gestion des pêches pour la recherche économique. Plusieurs communications et une table ronde se sont centrées sur la filière, la consommation et les marchés des produits de la mer: ces thèmes mobilisent de plus en plus l’attention des économistes européens.

The development of a sensory evaluation structure inside a reasearch institute is presented using few examples of data processing collected during training tests followed by volunteers. Statistical methods are proposed to evaluate various aptitudes of each panel member : aptitude to describe objectively the sensorial characteristics of marint. products, aptitude to discriminate flavors, to memorize odors, aptitude to rank samples according to the intensity of one characteristic, attitude of each person towards a scoring scale and also aptitude to give reliable answers. These methods, though widely used (Principal Component Analysis, Correspondence Analysis) give a synthetical view of individual qualities and also general aptitudes of the group., Ce rapport fait le point sur le travail réalisé lors de la mise en place, au centre IFREMER de Nantes, d'un jury interne d'analyse sensorielle, dont la vocation sera d'évaluer des produits d'origine marine. Les volontaires recrutés parmi le personnel ont subi diverses épreuves destinées à tester leurs aptitudes sensorielles. Les performances évaluées concernent: l'aptitude à décrire objectivement l'ensemble des caractéristiques sensorielles d'un produit, l'aptitude à discriminer les saveurs fondamentales et certaines odeurs spécifiques des produits marins, l'aptitude à reconnaître et à mémoriser diverses odeurs, à classer des produits en fonction de l'intensité croissante d'une caractéristique, ainsi que l'aptitude à donner des réponses répétables. Dans le même temps, le panel des dégustateurs s'est familiarisé avec les principales notions de caractérisation des produits alimentaires et a été sensibilisé aux méthodes d'évaluation. Des méthodes statistiques telles que l'analyse en composantes principales (ACP), l'analyse factorielle des correspondances (AFC), sont proposées comme outils d'interprétation des résultats. Ces méthodes déjà largement utilisées permettent d'obtenir une vue plus synthétique des aptitudes individuelles et du groupe en général. La cartographie sensorielle ainsi obtenue pour chaque individu devrait permettre de mieux gérer le panel, en formant des sous groupes d'évaluation en fonction du test à mettre en oeuvre et des aptitudes enregistrées.