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Auteur Espinosa, F.; Rivera-Ingraham, G.A.
Titre Subcellular evidences of redox imbalance in well-established populations of an endangered limpet. Reasons for alarm? Type Article scientifique
Année 2016 Publication Revue Abrégée Mar. Pollut. Bull.
Volume 109 Numéro 1 Pages 72-80
Mots-Clés antioxidant enzymes; community structure; Conservation; different environmental-conditions; Heavy metals; heavy-metals; marine-invertebrates; mussel mytilus-edulis; Oxidative stress; oyster crassostrea-virginica; Patella ferruginea; patella-ferruginea gastropoda; Pollution; trace-metals
Résumé Intertidal species are more vulnerable to anthropogenic disturbances than others inhabiting subtidal and offshore habitats. Coastal development frequently results in trace-metal pollution. For endangered species such as Patella ferruginea it can be a high risk that leads local populations to extinction. Three localities were surveyed, one within a natural and unpolluted area and the other two within the harbor of Ceuta (Strait of Gibraltar), on breakwaters outside and inside. The specimens collected inside the harbor reached 3-fold higher Hg content than for those incoming from the natural area. PERMANOVA test indicated that metal composition of the specimens from inside the harbor was different from the rest. In addition, evidence of cell damage was detected in the specimens from the harbor area. This highlights the urgency of undertaking a physiological evaluation of some of the most vulnerable populations, establishing eco-physiological protocols for monitoring and managing populations settled on artificial substrata. (C) 2016 Elsevier Ltd. All rights reserved.
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Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0025-326x ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1635
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Auteur Richard, M.; Bourreau, J.; Montagnani, C.; Ouisse, V.; Le Gall, P.; Fortune, M.; Munaron, D.; Messiaen, G.; Callier, M.D.; Roque d'Orbcastel, E.
Titre Influence of OSHV-1 oyster mortality episode on dissolved inorganic fluxes: An ex situ experiment at the individual scale Type Article scientifique
Année 2017 Publication Revue Abrégée Aquaculture
Volume 475 Numéro Pages 40-51
Mots-Clés carrying-capacity; Crassostrea gigas; crassostrea-gigas spat; eastern oyster; juvenile; la-madeleine quebec; mediterranean thau lagoon; Mineralisation; mortality; mussel mytilus-edulis; mu-var; Nutrient fluxes; Ostreid herpesvirus 1; ostreid herpesvirus-1 infection; oxygen consumption; oxygen-consumption rates; pacific oysters; Spat
Résumé Ostreid herpesvirus 1 (OsHV-1 mu var) infection has caused significant mortalities in juvenile oysters (Crassostrea gigas). In contrast to the practices of other animal production industries, sick and dead oysters are not separated from live ones and are left to decay in the surrounding environment, with unknown consequences on fluxes of dissolved materials. A laboratory approach was used in this study to test the influence of oyster mortality episode on dissolved inorganic fluxes at the oyster interface, dissociating (i) the effect of viral infection on metabolism of juvenile oysters and (ii) the effect of flesh decomposition on oxygen consumption and nutrient releases at the individual scale. Nine batches of juvenile oysters (Individual Total wet weight 1 g) were infected via injection of OsHV-1 enriched inoculums at different viral loads (108 and 109 OsHV-1 DNA copies per oyster) to explore infection thresholds. Oysters injected with filtered seawater were used as controls (C). Oysters were maintained under standard conditions to avoid stress linked to hypoxia, starvation, or ammonia excess. Before, after the injection and during the mortality episode, i.e. at days 1, 3, 7, 10 and 14, nine oysters per treatment were incubated in individual metabolic chambers to quantify oxygen, ammonium and phosphate fluxes at the seawater-oyster interface. Nine empty chambers served as a reference. Injections of the two viral loads of OsHV-1 induced similar mortality rates (38%), beginning at day 3 and lasting until day 14. The observed mortality kinetics were slower than those reported in previous experimental pathology studies, but comparable to those observed in the field (Thau lagoon, France). This study highlights that oxygen and nutrient fluxes significantly varied during mortality episode. Indeed (i) OsHV-1 infection firstly modifies oyster metabolism, with significant decreases in oxygen consumption and ammonium excretion, and (ii) dead oysters lead to a strong increase of ammonium (6 fold) and phosphate (41 fold) fluxes and a decrease in the N/P ratio due to mineralisation of their flesh. The latter may modify the structure of the planktonic community in the field during mortality episode. This study is a first step of the MORTAFLUX program. The second step was to in situ confirm this abnormal nutrient loading during a mortality episode and show its impact on bacterio-, phyto-and protozoo-plankton. (C) 2017 Elsevier B.V. All rights reserved.
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Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0044-8486 ISBN Médium
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Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2149
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