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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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Lopez-acosta, Maria; Leynaert, Aude; Chavaud, Laurent; Amice, Erwan; Bihannic, Isabelle; Le Bec, Thierry; Maldonado, Manuel. |
Sponges consume dissolved silicon (DSi) to build their skeletons. Few studies have attempted to quantify DSi utilization by these organisms and all available determinations come from laboratory measurements. Here we measured DSi consumption rates of the sponge Tethya citrina in its natural habitat, conducting 24h incubations in benthic chambers. Sponges consumed DSi at an average rate of 0.046 +/- 0.018 mu mol h(-1) mL(-1) when DSi availability in its habitat was 8.3 +/- 1.8 mu M. Such DSi consumption rates significantly matched the values predicted by a kinetic model elsewhere developed previously for this species through laboratory incubations. These results support the use of laboratory incubations as a suitable approach to learn about DSi consumption.... |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00605/71664/70115.pdf |
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Frere, L.; Paul-pont, I.; Rinnert, Emmanuel; Petton, Sebastien; Jaffre, J; Bihannic, Isabelle; Soudant, P.; Lambert, C.; Huvet, Arnaud. |
The concentration and spatial distribution of microplastics in the Bay of Brest (Brittany, France) was investigated in two surveys. Surface water and sediment were sampled at nine locations in areas characterized by contrasting anthropic pressures, riverine influences or water mixing. Microplastics were categorized by their polymer type and size class. Microplastic contamination in surface water and sediment was dominated by polyethylene fragments (PE, 53–67%) followed by polypropylene (PP, 16–30%) and polystyrene (PS, 16–17%) microparticles. The presence of buoyant microplastics (PE, PP and PS) in sediment suggests the existence of physical and/or biological processes leading to vertical transfer of lightweight microplastics in the bay. In sediment (upper... |
Tipo: Text |
Palavras-chave: Microplastic; Coastal ecosystem; Surface water; Sediment; Raman spectroscopy; Hydrodynamic; Dispersal particle modelling. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00379/48994/51083.pdf |
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