Catalogue of parasites and diseases of the common cockle Cerastoderma edule

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Atlas des parasites et maladies de la coque commune Cerastoderma edule

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Inventario de parasitos e enfermidades do berberecho Cerastoderma edule

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Catálogo de parasitas e patologias do berbigão-vulgar Cerastoderma edule

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Communautés métazooplanctoniques de la zone épipélagique de deux environnements contrastés, le plateau des Kerguelen et la mer Méditerranée : caractérisation, distribution spatiale et rôle dans l'écosystème.

Mesozooplankton from the epipelagic layer (0-200 m) was studied in two contrasted ecosystems: the first one is located in the Austral Ocean, around the Southern part of the Kerguelen shelf and over the HNLC (High Nutrient Low Chlorophyll) area, at the end of summer bloom period supported by natural iron enrichment (KEOPS, January-February 2005). The second study focused on the whole Mediterranean Sea, along a 3 000 km transect characterized by an oligotrophy gradient decrease from West to East (BOUM, June-July 2008) with low phosphorus concentration. Mesozooplanktonic community was characterized by both its stock composition (abundance and biomass) and its structure (taxonomic composition and size spectrum). Spatial distribution at the regional scale was studied and linked to different environmental and trophic parameters. The community impact on primary production was also estimated from different physiological process analyses (ingestion, respiration and excretion). Mesozooplanktonic community showed higher abundance and biomass over the Kerguelen shelf than in HNLC area. The community was essentially composed by copepodite stages, large quantity of exuviae and high respiration rates suggesting active growth. However, phytoplankton based ingestion rates were low implying the use of other food source such as microzooplankton. In the Mediterranean, abundance showed an increasing westward gradient with a southward decreasing gradient in the Occidental Basin. This distribution was strongly linked to the chlorophyll concentration. Mesozooplankton grazing on primary producers was important. Biogeochemical flux associated with the metabolic activities supported in excess of 100 % of the primary production needs in term of carbon, nitrogen and phosphorus. Relationships between the specific diversity and the environmental variables (physical, chemical and biological) showed a high regionalization in the Mediterranean Sea whereas in the Kerguelen shelf these relations are weak.Le mésozooplancton de la couche épipélagique (0-200 m) a été étudié dans deux écosystèmes contrastés ; le premier se situe au niveau de la partie sud du plateau des Kerguelen et d'une partie de la zone HNLC (High Nutrient Low Chlorophyll) de l'océan Austral, à la fin de floraison estivale entretenue par des apports naturels en fer (KEOPS : janvier-février 2005). La deuxième étude s'est intéressée à l'ensemble de la Méditerranée, le long d'une radiale de 3 000 km caractérisée par un degré d'oligotrophie croissant d'Ouest en Est (BOUM juin-juillet 2008). La communauté mésozooplanctonique a été caractérisée à la fois par la description des stocks (abondance et biomasse) et de sa structure (composition taxonomique et spectre de taille). La distribution spatiale à l'échelle régionale a été étudiée et mise en relation avec différents paramètres environnementaux et trophiques. L'impact de la communauté sur les producteurs primaires a été également estimé à partir de l'analyse de différents processus physiologiques (ingestion, respiration et excrétion). La communauté mésozooplanctonique australe était caractérisée par de fortes abondance et biomasse sur le plateau des Kerguelen et plus faible en zone HNLC. Elle était composée essentiellement de stades copépodites avec une présence importante de mues et des taux élevés de respiration indiquant une croissance active. Cependant l'impact du broutage sur la production primaire était faible ce qui suggère l'utilisation d'autres ressources alimentaires tel que le microzooplancton. En Méditerranée, l'abondance zooplanctonique présentait un gradient croissant est-ouest auquel s'ajoutait un gradient nord-sud décroissant dans le bassin occidental. Cette distribution était fortement liée à la quantité de chlorophylle a. Le broutage du mésozooplancton sur les producteurs primaires était important. Les flux de matière liés à l'activité métabolique supportaient plus de 100 % des besoins de la production primaire en carbone, azote et phosphore. L'étude des relations entre la diversité spécifique et les variables environnementales (physique, chimique et biologique) a révélé une forte régionalisation en Méditerranée alors que sur le plateau des Kerguelen ces relations sont faibles

Zooplankton community structure, biomass and role in carbon fluxes during the second half of a phytoplankton bloom in the eastern sector of the Kerguelen Shelf (January-February 2005)

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Invasion along the French Atlantic coast by the non-native, carnivorous planktonic comb jelly Mnemiopsis leidyi: can an impact on shellfish farming be expected?

The distribution range of the American comb jelly Mnemiopsis leidyi has expanded across Europe for several decades, particularly in the eastern Atlantic and Mediterranean Sea. This study aims to assess its expansion along the French Atlantic coast, mainly in the Bay of Biscay and Iroise Sea, since the first record in 2014. Mnemiopsis leidyi is now clearly established along 500 km of coastline, from the coast of Lorient to Arcachon Bay, which is the southernmost colonised area in the eastern Atlantic to date. It will likely colonise the Spanish Gulf coast in the near future through natural dispersal via currents, as has occurred between the Gironde estuary and Arcachon Bay. We quantify that this species now colonises nearly 45% of the French coastline. The invaded area includes the main estuaries of the Seine, Loire, Gironde and Rhône rivers, where M. leidyi populations may constitute reservoirs for colonising other harbours through merchant vessel traffic via ballast water. Finally, the Marennes- Oléron Bay and Arcachon Bay are the two main spat-producing regions for the Pacific oyster Magallana gigas in France. As M. leidyi consumes bivalve larvae, the potential economic and ecological impacts on this shellfish industry are discussed

Microplastics FTIR characterisation and distribution in the water column and digestive tracts of small pelagic fish in the Gulf of Lions

WOS:00047431950005

Mesozooplankton structure and functioning during the onset of the Kerguelen spring bloom: first results of the KEOPS2 survey

International audienceDuring the KEOPS II survey in spring (Oct-Nov 2011), the northeast and southeast region Kerguelen Island (between 46°59S and 50°37 S and 69°50E and 74°59E) were intensively studied to understand the physical and biogeochemical processes governing the onset of the Kerguelen spring bloom. Mesozooplankton community spatial distribution, taxonomy structure, size structure and biomass were studied from 41 zooplankton net tow samples -(0-250m vertical net tows) analyzed both with a ZOOSCAN and a binocular. 13C and 15N content between distinct size fractions, pigment gut contents and respiration rates of of dominant species were measured as well. Here we report on first results obtained along two transects (East-West and North South) and along a lagrangian sampling in the central part of the region during the bloom development. Biomass, abundance and size structures show temporal and spatial differences linked to the different water masses and trophic conditions. Day-night sampling revealed strong variations in abundance and biomass during the bloom phase due to large organisms, mainly euphausiids. Different spatial patterns of zooplankton size spectra were found with the highest slope values on the shelf area showing a large ratio of small organisms and the lowest within the central part of the region