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Oleszczuk, Barbara; Michaud, Emma; Morata, Nathalie; Renaud, Paul E.; Kędra, Monika. |
The aim of this study was to assess bioturbation rates in relation to macrozoobenthos and environmental variables in the Svalbard fjords, Barents Sea and Nansen Basin during spring to summer transition. The results showed differences in benthic community structure across sampled area in relation to sediment type and phytopigment content. Fjords, Barents Sea and the shallow parts of Nansen Basin (<400 m) were characterized by high functional groups diversity, and by biodiffusive and non-local rates ranging from 0.05 to 1.75 cm−2 y−1 and from 0.2 to 3.2 y−1, respectively. The deeper parts of Nansen Basin, dominated by conveyors species, showed only non-local transport rates (0.1–1 y−1). Both coefficients intensity varied with benthic biomass. Non-local... |
Tipo: Text |
Palavras-chave: Non-local transport; Biodiffusive transport; Macrozoobenthos; Spring season; Sea ice cover; Arctic Ocean. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00502/61329/64901.pdf |
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Aschenbroich, Adelaide; Michaud, Emma; Stieglitz, Thomas; Fromard, Francois; Gardel, Antoine; Tavares, Marcos; Thouzeau, Gerard. |
This study in French Guiana evaluates the changes of crab assemblages and their bioturbation activities between mangrove early stages (pioneer and young mangrove) and within stages by taking their spatial heterogeneity (tidal channels, flat areas, pools) into account. The results show differences in crab assemblage structure between and within the early stages of mangrove in relation to microhabitat and sediment characteristics. The sediment reworking rates are a function of the biomass or density of particular species (Ucides cordatus, Uca cumulanta) and burrower functional groups. Crab species or functional interaction mediate changes in sediment reworking rates suggesting the need to consider entire benthic communities rather than single species. This... |
Tipo: Text |
Palavras-chave: Mangroves; Crabs; Community composition; Bioturbation; French Guiana; Amazon. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00350/46154/45852.pdf |
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Michelet, Claire; Zeppilli, Daniela; Hubas, Cédric; Baldrighi, Elisa; Cuny, Philippe; Dirberg, Guillaume; Militon, Cécile; Walcker, Romain; Lamy, Dominique; Jézéquel, Ronan; Receveur, Justine; Gilbert, Franck; Houssainy, Amonda El; Dufour, Aurélie; Heimbürger-boavida, Lars-eric; Bihannic, Isabelle; Sylvi, Léa; Vivier, Baptiste; Michaud, Emma. |
Bioindicators assess the mangroves ecological state according to the types of pressures but they differ with the ecosystem’s specificities. We investigated benthic meiofauna diversity and structure within the low human-impacted mangroves in French Guiana (South America) in response to sediment variables with various distances to the main city. Contaminant’s concentrations differed among the stations, but they remained below toxicity guidelines. Meiofauna structure (Foraminifera, Kinorhyncha, Nematoda) however varied accordingly. Nematode’s identification brought details on the sediment’s quality. The opportunistic genus Paraethmolaimus (Jensen, 1994) strongly correlated to the higher concentrations of Hg, Pb. Anoxic sediments were marked by organic... |
Tipo: Text |
Palavras-chave: Mangroves; Biodiversity; Meiofauna; Nematode; Anthropogenic pressures; Natural contamination; South America. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00684/79587/82274.pdf |
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Ray, Raghab; Thouzeau, Gerard; Walcker, Romain; Vantrepotte, Vincent; Gleixner, Gerd; Morvan, Sylvain; Devesa, Jeremy; Michaud, Emma. |
There is growing evidence that a substantial fraction of the dissolved organic and inorganic carbon (DOC and DIC) and particulate organic carbon (POC) can be exported from mangroves to the ocean. Yet our understanding of C fluxes in mangrove forests is limited to only few regional studies that exclude the world's longest sediment dispersal system connected to the Amazon River. The present study aims at (1) examining tidal fluctuations of DOC, POC, and DIC; their isotopes; and optical properties such as chromophoric dissolved organic matter (CDOM) and (2) estimating their exchange fluxes between the mangroves and adjacent coastal water in the Sinnamary estuary, French Guiana. Time series observation highlighted that physical processes coupled to tides... |
Tipo: Text |
Palavras-chave: Organic matter; Tidal cycle; Carbon flux; Mangroves; French Guiana. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75488/76339.pdf |
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Baldrighi, Elisa; Dovgal, Igor; Zeppilli, Daniela; Abibulaeva, Alie; Michelet, Claire; Michaud, Emma; Franzo, Annalisa; Grassi, Eleonora; Cesaroni, Lucia; Guidi, Loretta; Balsamo, Maria; Sandulli, Roberto; Semprucci, Federica. |
Epibiosis is a common phenomenon in marine systems. In marine environments, ciliates are among the most common organisms adopting an epibiotic habitus and nematodes have been frequently reported as their basibionts. In the present study, we report several new records of peritrich and suctorian ciliates-nematode association worldwide: from a deep-sea pockmark field in the NW Madagascar margin (Indian Ocean), from a shallow vent area in the Gulf of Naples (Mediterranean, Tyrrhenian Sea), in a MPA area in the Gulf of Trieste (Mediterranean, Adriatic Sea), from a mangrove system in French Guiana (South America, Atlantic Ocean), and from the Maldivian Archipelago. In addition, three new species of Suctorea from the Secca delle Fumose shallow vent area (Gulf of... |
Tipo: Text |
Palavras-chave: Epibiosis; Ciliophora; Suctorea; Nematoda; Meiofauna; Biodiversity. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00632/74417/74132.pdf |
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Berge, Jorgen; Daase, Malin; Renaud, Paul E.; Ambrose, William G., Jr.; Darnis, Gerald; Last, Kim S.; Leu, Eva; Cohen, Jonathan H.; Johnsen, Geir; Moline, Mark A.; Cottier, Finlo; Varpe, Oystein; Shunatova, Natalia; Balazy, Piotr; Morata, Nathalie; Massabuau, Jean-charles; Falk-petersen, Stig; Kosobokova, Ksenia; Hoppe, Clara J. M.; Weslawski, Jan Marcin; Kuklinski, Piotr; Legezynska, Joanna; Nikishina, Daria; Cusa, Marine; Kedra, Monika; Wlodarska-kowalczuk, Maria; Vogedes, Daniel; Camus, Lionel; Tran, Damien; Michaud, Emma; Gabrielsen, Tove M.; Granovitch, Andrei; Gonchar, Anya; Krapp, Rupert; Callesen, Trine A.. |
The current understanding of Arctic ecosystems is deeply rooted in the classical view of a bottom-up controlled system with strong physical forcing and seasonality in primary-production regimes. Consequently, the Arctic polar night is commonly disregarded as a time of year when biological activities are reduced to a minimum due to a reduced food supply. Here, based upon a multidisciplinary ecosystem-scale study from the polar night at 79 degrees N, we present an entirely different view. Instead of an ecosystem that has entered a resting state, we document a system with high activity levels and biological interactions across most trophic levels. In some habitats, biological diversity and presence of juvenile stages were elevated in winter months compared to... |
Tipo: Text |
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Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00288/39885/38620.pdf |
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