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| Chapperon, Coraline; Clavier, Jacques; Dugué, Clément; Amice, Erwan; Le Goff, Marion; Roussel, Sabine. |
| Abalone (Haliotis spp.) are commercially important marine shellfish species worldwide. Knowledge about the physiology of abalone that impacts life-history traits is important for a better understanding of the biology of the species and the impact of stressful husbandry procedures at different seasons. The present study quantified the seasonal and diurnal variations in four physiological parameters of the European species Haliotis tuberculata, i.e. carbon aerial and aquatic respiration, calcification and excretion rates, and the effect of prolonged aerial exposure upon abalone aerial respiration. We also investigated the effect of individual size upon these physiological parameters. Aquatic respiration and calcification rates showed an allometric... |
| Tipo: Text |
Palavras-chave: Ormer; Metabolism; Carbon fluxes; Physiology. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00431/54243/55886.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.... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00605/71664/70115.pdf |
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| Guédron, S.; Audry, S.; Acha, D.; Bouchet, S.; Point, D.; Condom, T.; Heredia, C.; Campillo, S.; Baya, A.; Groleau, A.; Amice, Erwan; Amouroux, D.. |
| Monomethylmercury (MMHg) concentrations in aquatic biota from Lake Titicaca are elevated although the mercury (Hg) contamination level of the lake is low. The contribution of sediments to the lake MMHg pool remained however unclear. In this work, seven cores representative of the contrasted sediments and aquatic ecotopes of Lake Titicaca were sliced and analyzed for Hg and redox-sensitive elements (Mn, Fe, N and S) speciation in pore-water (PW) and sediment to document early diagenetic processes responsible for MMHg production and accumulation in PW during organic matter (OM) oxidation. The highest MMHg concentrations (up to 12.2 ng L−1 and 90% of THg) were found in subsurface PWs of the carbonate-rich sediments which cover 75% of the small basin and 20%... |
| Tipo: Text |
Palavras-chave: Methylmercury; Lake sediment; Early diagenesis; High altitude ecosystem; Diffusive fluxes. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00615/72735/71843.pdf |
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| Clavier, Jacques; Chauvaud, Laurent; Amice, Erwan; Lazure, Pascal; Van Der Geest, Matthijs; Labrosse, Pierre; Diagne, Ahmed; Carlier, Antoine; Chauvaud, Sylvain. |
| Benthic primary production and respiration were investigated at 4 sites representative of the major coastal communities bordering the Sahara Desert in the Banc d'Arguin, Mauritania, Western Africa. These sites correspond to intertidal Zostera noltii beds (270 km(2)), intertidal bare sediments (88 km(2)), subtidal Cymodocea nodosa beds (374 km(2)), and subtidal bare sediments (311 km(2)). At each site, production-irradiance relationships were established in situ in November 2008 and January 2010, and used to calculate daily carbon fluxes for these communities. In intertidal areas, compared to emersion, the gross maximal photosynthetic rates for Z. noltii bed and bare sediment communities were on average 8-and 7-fold higher during immersion, respectively;... |
| Tipo: Text |
Palavras-chave: Seagrass; Carbon metabolism; Intertidal; Subtidal; Respiration; Primary; Production; Western Africa. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00189/29987/28460.pdf |
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