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Bouchet, Vincent; Debenay, Vincent; Sauriau, Pierre-guy; Radford Knoery, Joel; Soletchnik, Patrick. |
Sediment cores were collected from April to August 2004 on tidal mudflats of the macrotidal Marennes-Oléron Bay (SW France), famous for the cultivation of Pacific oysters (Crassostrea gigas). The response of living (stained) benthic foraminifera to short-term biogeochemical disturbances in the sediment and overlying water, which may be involved in oyster summer mortality, was monitored. Short-term hypoxia occurred in early June, in conjunction with a sudden rise in temperature. In mid-June, the ammonia content of sediment porewater increased, leading to potentially maximal flux towards overlying waters. Foraminiferal assemblages, particularly in the topmost layer, were altered. Ammonia tepida was the most tolerant to temperature increase and hypoxic... |
Tipo: Text |
Palavras-chave: Marennes Oléron bay; Aquaculture; Crassostrea gigas; Intertidal; Ammonium; Hypoxia; Organic matter; Living benthic foraminifera. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2586.pdf |
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Bouchet, Vincent; Debenay, Jean-pierre; Sauriau, Pierre-guy. |
Large populations of the living benthic foraminifera Quinqueloculina carinatastriata (Wiesner, 1923) are reported for the first time from intertidal mudflats of the French Atlantic coast (Marennes-Oléron Bay and Ile de Ré). Maximum abundance of living specimens was recorded in early autumn. The species was previously described from the Adriatic and Tyrrhenian Seas (central Mediterranean Sea) and reported from the Eastern Mediterranean and Red Seas, as well as tropical and subtropical regions. A survey of available literature to trace records of the species in muddy shallow habitats along the western coasts of Europe and Africa reveals that the species is unrecorded from the Western Mediterranean Sea and is unknown in the eastern Atlantic Ocean from the... |
Tipo: Text |
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Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2587.pdf |
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Bouchet, Vincent; Sauriau, Pierre-guy; Debenay, J.p.; Mermillod-blondin, F; Schmidt, S; Amiard, J.c.; Dupas, B. |
We investigated the influence of bioturbation by macrofauna on the vertical distribution of living (stained) benthic foraminifera in marine intertidal sediments. We investigated the links between macrofaunal bioturbation and foraminiferal distribution, by sampling from stations situated on a gradient of perturbation by oyster-farming, which has a major effect on benthic faunal assemblages. Sediment cores were collected on the French Atlantic coast, from three intertidal stations: an oyster farm, an area without oysters but affected by oyster biodeposits, and a control station. Axial tomodensitometry (CT-scan) was used for three-dimensional visualization and two-dimensional analysis of the cores. Biogenic structure volumes were quantified and compared... |
Tipo: Text |
Palavras-chave: Macrofauna; Living foraminifera; Interspecific interaction; CT scan; Bioturbating modes; Biogenic structures. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6146.pdf |
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Soletchnik, Patrick; Bouchet, Vincent; Malestroit, Pascal; Seugnet, Jean-luc; Blouin, Frederic; Radford-knoery, Joël; Burgeot, Thierry; Sauriau, Pierre-guy. |
In the scope of the study of the "on-bottom/off-bottom" mortality model in the south of the Marennes Oléron Bay, the result of the 2003 multidisciplinary study (Dynamor) appears to be the hypothesis of an acute stress, "ultimate" trigger of the mortality episodes in June. In 2004 we aim to look for the nature of this stress through the physico-chemical analysis of the sediment (Eh, pH, sulphides and ammoniacal nitrogen), the organic matter and chlorophyll load on the surface of the sediment between April and July. Herbicides are also measured in the water column, south of the bay (Seudre), during the same period. A "precocious" (around the first week of June) and "weak" (lower mortality rate on this working site since 1997) mortality peak happens when the... |
Tipo: Text |
Palavras-chave: Bassin Marennes Oléron; Phytobenthos; Mortalité; Crassostrea gigas; Foraminiferes benthiques; Répartition verticale; Sédiment; Huître; Echantillonnage. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/rapport-3383.pdf |
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