Potentialités du radar SAR en halieutique : application à la pêche thonière de surface et à la pêche artisanale

... L'expérimentation HAREM (Halieutique et Radar : Expérimentation en Méditerranée), en prélude à un véritable programme, a évalué, pour la première fois, les potentialités, la qualité et l'originalité des données acquises en mer par ce type de radar en matière de biologie des pêches et d'environnement halieutique. HAREM a été menée en août 1989, avec le radar allemand E-SAR du DLR monté sur un avion Dornier 228. La difficulté principale a été d'estimer le créneau météorologique d'abord, puis halieutique, favorable sur quelques jours, de façon à disposer simultanément et en un même lieu des pêcheurs, des bancs de thons et des acquisitions radar. Dès les premiers vols, nous avons pu vérifier notre hypothèse : bancs de thons, cétacés, ainsi qu'engins de pêche, (bateaux, filets, pièges à poissons) sont détectables et identifiables avec un radar SAR (bande C, polarisation VV) par l'intermédiaire du signal généré par la déformation de la surface de l'eau. L'objectif de HAREM a été ainsi complètement atteint. A partir des données recueillies, des simulations de type ERS-1, par dégradation géométrique des données, ont été effectuées et semblent prometteuses en ce qui concerne la pêche thonièr

Pleuronectes platessa, una especie fantasma en el Mediterráneo?

European plaice Pleuronectes platessa often appears in ichthyological check lists for the Mediterranean Sea, as well as in regional field guides and even in some official national landings statistics. However we have not found a single ichthyologist or fisheries biologist who has actually observed this fish in the Mediterranean. The ichthyologic sources available, from classical antiquity to recent times, were checked in order to follow the track of the citations (i.e. true field observations or citations of former authors), and to try to detect misidentifications, if any. Few of these citations appear to be reliable and misidentifications with flounder Platichthys flesus are frequent. Recent scientific trawl surveys have not reported any observations of plaice. The statistics provided by France to the FAO with positive catches of P. platessa appear to be misidentifications of P. flesus. Plaice may have been present in some areas of the Mediterranean in the past, as a result of climatic changes related to the ice age. However, the species seems to be absent now. We propose that this species should be removed from the ichthyofauna records of the Mediterranean.La especie Pleuronectes platessa aparece a menudo en los listados de peces del Mediterráneo, guías de identificación de especies mediterráneas, e incluso en estadísticas oficiales. Sin embargo no hemos encontrado un solo ictiólogo o biólogo pesquero que la haya observado en dicho mar. Se han comprobado las obras de ictiología desde la antiguedad clásica hasta nuestros días con el fin de seguir la pista de las citas, por si son auténticas observaciones de campo o citas de autores anteriores, y tratar de detectar errores de identificación en caso que los haya. Pocas citas aparecen como verdaderamente confiables, la mayoría no lo son. Las confusiones con Platichthys flesus son frecuentes. Las campañas científicas recientes tampoco han proporcionado ninguna observación de Pleuronectes platessa. Las estadísticas que Francia ha proporcionado a la FAO con capturas de esta especie, resultan ser confusiones de identificación con Platichthys flesus. Pleuronectes platesa podría haber estado presente en algunas áreas del Mediterráneo en el pasado como resultado de los cambios climáticos relacionados con la pequeña edad del hielo. No obstante parece que en la actualidad es ausente. Proponemos eliminar la especie de los registros de la fauna ictiológica del Mediterráneo

Marine Strategy Framework Directive - Task Group 3 Report - Commercially exploited fish and shellfish

The Marine Strategy Framework Directive (2008/56/EC) (MSFD) requires that the European Commission (by 15 July 2010) should lay down criteria and methodological standards to allow consistency in approach in evaluating the extent to which Good Environmental Status (GES) is being achieved. ICES and JRC were contracted to provide scientific support for the Commission in meeting this obligation. A total of 10 reports have been prepared relating to the descriptors of GES listed in Annex I of the Directive. Eight reports have been prepared by groups of independent experts coordinated by JRC and ICES in response to this contract. In addition, reports for two descriptors (Contaminants in fish and other seafood and Marine Litter) were written by expert groups coordinated by DG SANCO and IFREMER respectively. A Task Group was established for each of the qualitative Descriptors. Each Task Group consisted of selected experts providing experience related to the four marine regions (the Baltic Sea, the Northeast Atlantic, the Mediterranean Sea and the Black Sea) and an appropriate scope of relevant scientific expertise. Observers from the Regional Seas Conventions were also invited to each Task Group to help ensure the inclusion of relevant work by those Conventions. This is the report of Task Group 3 Commercially exploited fish and shellfish.JRC.DG.G.4-Maritime affair

Fisheries in the Mediterranean

The aim of this paper is to give a description of the Mediterranean fisheries, and its level of exploitation and to address the main questions dealing with its management. The Mediterranean is a semi-enclosed marine area with generally narrow continental shelves. The primary production of the Mediterranean is among the lowest in the world (26-50g C m-2 y-1). The Mediterranean fisheries can be broken down into three main categories: small scale fisheries, trawling and seining fisheries, which operated on demersal, small pelagic and large pelagic resources. After a general description of the state of the resources in the different areas of the Mediterranean it is concluded that (a) the overall pictures from the western to the eastern Mediterranean are not considerably different, (b) the total landings in the Mediterranean have been increased the last decades, and (c) from the perspective of stock assessment, the very few available time series data show stable yield levels. In general fisheries management in the Mediterranean is at a rela- tively early stage of development, judging by the criteria of North Atlantic fisheries. Quota systems are generally not applied, mesh-size regulations usually are set at low levels relative to scientific advice, and effort limitation is not usually applied or, if it is, is not always based on a formal resource assessment. The conservation/management measures applied by the Mediterranean countries can be broadly separated into two major categories: those aiming to keep the fishing effort under control and those aiming to make the exploitation pattern more rational. The most acute problems in the management of the Mediterranean resources are the multispecificity of the catches and the lack of reliable official statistics

Demandas sociales / dispositivos grupales / comunitarios

Nos proponemos reflexionar acerca de las múltiples demandas sociales que convergen en el campo de la salud mental comunitaria, pensando estas cuestiones desde una perspectiva que privilegia los acontecimientos que promueven los abordajes grupales.Mesas temáticas autoconvocadas: Formación en psicología y demandas socialesFacultad de Psicologí

Demandas sociales / dispositivos grupales / comunitarios

Nos proponemos reflexionar acerca de las múltiples demandas sociales que convergen en el campo de la salud mental comunitaria, pensando estas cuestiones desde una perspectiva que privilegia los acontecimientos que promueven los abordajes grupales.Mesas temáticas autoconvocadas: Formación en psicología y demandas socialesFacultad de Psicologí

Demandas sociales / dispositivos grupales / comunitarios

Nos proponemos reflexionar acerca de las múltiples demandas sociales que convergen en el campo de la salud mental comunitaria, pensando estas cuestiones desde una perspectiva que privilegia los acontecimientos que promueven los abordajes grupales.Mesas temáticas autoconvocadas: Formación en psicología y demandas socialesFacultad de Psicologí

Composition of fish communities in macrotidal salt marshes of the Mont Saint-Michel bay (France)

At least 100 fish species are known to be present in the intertidal areas (estuaries, mudflats and salt marshes) of Mont Saint-Michel Bay. These and other comparable shallow marine coastal waters, such as estuaries and lagoons, play a nursery role for many fish species. However, in Europe little attention has been paid to the value of tidal salt marshes for fishes. Between March 1996 and April 1999, 120 tides were sampled in a tidal creek. A total of 31 species were caught. This community was largely dominated by mullets (Liza ramada represent 87% of the total biomass) and sand gobies(Pomatoschistus minutus and P. lozanoi represent 82% of the total numbers). These species and also Gasterosteus aculeatus, Syngnathus rostellatus, Dicentrarchus labrax, Mugil spp., Liza aurata and Sprattus sprattus were the most frequent species (>50% of monthly frequency of occurrence). In Europe, salt marshes and their creeks are flooded only during high spring tides. So, fishes only invade this environment during short immersion periods, and no species can be considered as marsh resident. But, the salt marsh was colonized by fish every time the tide reached the creek, and during the short time of flood, dominant fishes fed actively and exploited the high productivity. Nevertheless, this study shows that there is little interannual variation in the fish community and there are three ‘ seasons ’ in the fish fauna of the marsh. Marine straggler and marine estuarine dependent species colonize marshes between spring (recruitment period in the bay) and autumn before returning into deeper adjacent waters. Estuarine fishes are present all year round with maximum abundances in the end of summer. The presence of fishes confirms that this kind of wetland plays an important trophic and nursery role for these species. Differences in densities and stages distribution of these species into Mont Saint-Michel systems (tidal mudflats, estuaries and tidal salt marshes) can reduce the trophic competition