Consulta: creatorFacets:"Laes, Agathe"
Registros recuperados: 10
Data/hora: 01/06/2024 09:28:44

New instruments to monitor coastal sea water masses according to European Water Framework Directive, Trophimatique project
Provedor de dados: 5
Autores: Repecaud, Michel; Degres, Yves; Bernard, Nathalie; Allenou, Jean-pierre; Aoustin, Yannick; Arrondeau, Jean-pierre; Bouget, Jean-francois; Bucas, Karenn; Daniel, Anne; Guillaud, Jean-francois; Hamon, Michel; Jegou, Paul; Laes, Agathe; Le Roux, Dominique; Le Piver, David; Quemener, Loic; Rolin, Jean-francois; Rudelle, Tiphaine; Legrand, Jacques; Vuillemin, Renaud.
The automated monitoring of physico-chemical parameters in the coastal zone has been using large buoys and fixed infrastructures. A better understanding of many estuaries is needed in order to fulfil the agenda and requirements of the European Water Framework Directive. In order to address the fluxes of nutrients as well as algal blooms and low oxygen events, the "TROPHIMATIQUE" project has developed a new generation of instruments able to be deployed in sea waters. The smaller size of the new instruments is intended to facilitate the maintenance. A new multi-parameter probe has been developed. The measurements of all nutrients are performed thanks to the CHEMINI flow injection analysers for nitrate, ammonia, silicate and phosphate. A sampler using similar...
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00107/21807/20276.pdf

Impact of environmental factors on in situ determination of iron in seawater by flow injection analysis
Provedor de dados: 5
Autores: Laes, Agathe; Vuillemin, Renaud; Leilde, Bernard; Sarthou, Géraldine; Bournot Marec, Claudie; Blain, Stéphane.
A sensitive method for iron determination in seawater has been adapted on a submersible chemical analyser for in situ measurements. The technique is based on flow injection analysis (FIA) coupled with spectrophotometric detection. When direct injection of seawater was used, the detection limit was 1.6 nM, and the precision 7%, for a triplicate injection of a 4 nM standard. At low iron concentrations, on line preconcentration using a column filled with 8-hydroxyquinoline (8HQ) resin was used. The detection limit was 0.15 nM (time of preconcentration = 240 s), and the precision 6%, for a triplicate determination of a I nM standard, allowing the determination of Fe in most of the oceanic regimes, except the most depleted surface waters. The effect of...
Tipo: Text
Palavras-chave: Temperature and pressure effects; Submersible chemical analyser; Seawater; In situ measurements; Iron; Flow injection analysis.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-1209.pdf

Sources and transport of dissolved iron and manganese along the continental margin of the Bay of Biscay
Provedor de dados: 5
Autores: Laes, Agathe; Blain, S; Laan, P; Ussher, S; Achterberg, E; Treguer, Paul; De Baar, H. J. W.
Dissolved iron (DFe; &lt;0.2 mu m) and dissolved manganese (DMn; &lt;0.2 mu m) concentrations were determined in the water column of the Bay of Biscay (eastern North Atlantic Ocean) in March 2002. The samples were collected along a transect traversing from the European continental shelf over the continental slope. The highest DFe and DMn concentrations (2.39 nM and 6.10 nM, respectively) were observed in the bottom waters on the shelf at stations closest to the coast. The release of trace metal from resuspended particles and the diffusion from pore waters were probably at the origin of elevated DFe and DMn concentrations in the Bottom Boundary Layer (BBL). In the slope region, the highest total dissolvable iron (TDFe), DFe and DMn values (24.6 nM, 1.58 nM...
Tipo: Text
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2689.pdf

Developing Autonomous Observing Systems for Micronutrient Trace Metals
Provedor de dados: 5
Autores: Grand, Maxime M.; Laes, Agathe; Fietz, Susanne; Resing, Joseph A.; Obata, Hajime; Luther, George W.; Tagliabue, Alessandro; Achterberg, Eric P.; Middag, Rob; Tovar-sánchez, Antonio; Bowie, Andrew R.
Trace metal micronutrients are integral to the functioning of marine ecosystems and the export of particulate carbon to the deep ocean. Although much progress has been made in mapping the distributions of metal micronutrients throughout the ocean over the last 30 years, there remain information gaps, most notable during seasonal transitions and in remote regions. The next challenge is to develop in situ sensing technologies necessary to capture the spatial and temporal variabilities of micronutrients characterized with short residence times, highly variable source terms, and sub-nanomolar concentrations in open ocean settings. Such an effort will allow investigation of the biogeochemical processes at the necessary resolution to constrain fluxes, residence...
Tipo: Text
Palavras-chave: Trace metals; Micronutrients; In situ chemical analyzers; In situ sensors; GEOTRACES; OceanObs'19; Ocean observing time series.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00482/59337/62116.pdf

Rhythms and Community Dynamics of a Hydrothermal Tubeworm Assemblage at Main Endeavour Field - A Multidisciplinary Deep-Sea Observatory Approach
Provedor de dados: 5
Autores: Cuvelier, Daphne; Legendre, Pierre; Laes, Agathe; Sarradin, Pierre-marie; Sarrazin, Jozee.
The NEPTUNE cabled observatory network hosts an ecological module called TEMPO-mini that focuses on hydrothermal vent ecology and time series, granting us real-time access to data originating from the deep sea. In 2011-2012, during TEMPO-mini's first deployment on the NEPTUNE network, the module recorded high-resolution imagery, temperature, iron (Fe) and oxygen on a hydrothermal assemblage at 2186 m depth at Main Endeavour Field (North East Pacific). 23 days of continuous imagery were analysed with an hourly frequency. Community dynamics were analysed in detail for Ridgeia piscesae tubeworms, Polynoidae, Pycnogonida and Buccinidae, documenting faunal variations, natural change and biotic interactions in the filmed tubeworm assemblage as well as links with...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00200/31164/29564.pdf

Determination of iron-porphyrin-like complexes at nanomolar levels in seawater
Provedor de dados: 5
Autores: Vong, Lilita; Laes, Agathe; Blain, Stéphane.
A new method for the non-specific determination of iron-porphyrin-like complexes in natural waters has been developed. It is based on the chemiluminescent oxidation of the luminol in the presence of dioxygen (O-2) at pH 13. The method has been implemented in a FIA manifold that allowed the direct injection of seawater. The limit of detection is 0.11 nM of equivalent hemin (Fe-protoporphyrin IX). Fe2+, Fe3+, H2O2, siderophore (deferoxamin mesylate), humic acid and phytic acid did not interfere when the), were present at the concentrations expected in seawater. Metal free porphyrin and Mg, Cu, Co porphyrin complexes did not induce a significant chemiluminescent signal. Poisoned unfiltered samples could be stored for several weeks before analyses. The new...
Tipo: Text
Palavras-chave: Chemiluminescence; Complexation; Flow injection; Seawater; Porphyrin; Iron.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3298.pdf

Endogenous versus exogenous factors: What matters for vent mussel communities?
Provedor de dados: 5
Autores: Sarrazin, Jozee; Portail, Marie; Legrand, E.; Cathalot, Cecile; Laes, Agathe; Lahaye, Noe; Sarradin, Pierre-marie; Husson, Berengere.
The factors influencing the structure of hydrothermal communities are not necessarily similar across geographical regions and vent fields. In the present study, we explore the role of environmental conditions on vent community structure at local and regional spatial scales, focusing on the assemblages dominated by the engineer species Bathymodiolus azoricus. Their presence in several vent fields on the northern Mid-Atlantic Ridge (MAR) represents a unique opportunity to compare their associated fauna and to better understand large-scale biodiversity patterns. Two types of factors were considered: exogenous ones such as the presence of biogeographical barriers, depth, and distance between sites, and those linked to the intrinsic characteristics of each...
Tipo: Text
Palavras-chave: Intra-field variability; Inter-field variability; Hydrothermal fauna; Abiotic factors; Diversity measures; Macrofauna; Meiofauna; Environmental drivers; Community structure; Habitats.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00615/72661/71671.pdf

On the nature of dissolved copper ligands in the early buoyant plume of hydrothermal vents
Provedor de dados: 5
Autores: Cotte, Laura; Omanovic, Dario; Waeles, Mathieu; Laes, Agathe; Cathalot, Cecile; Sarradin, Pierre-marie; Riso, Ricardo D.
Environmental contextCopper released by deep-sea hydrothermal vents has been recognised to be partly stabilised against precipitation by its complexation with strong Cu binding ligands. Yet, the sources and nature of these compounds in such environments are still not fully understood. This study shows that the Cu ligands detected are hydrothermally sourced and could be mainly inorganic sulfur species. AbstractThe apparent speciation of Cu in the early buoyant plume of two black smokers (Aisics and Y3) from the hydrothermal vent field Lucky Strike (Mid-Atlantic Ridge) was investigated using competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-AdCSV). We have assessed the apparent Cu-binding ligand concentration ([L]) and the...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00444/55558/57208.pdf

Autonomously profiling the nitrate concentrations in the ocean : the Pronuts project
Provedor de dados: 5
Autores: D'Ortenzio, Fabrizio; Le Reste, Serge; Lavigne, Heloise; Besson, F.; Claustre, H.; Coppola, Laurent; Dufour, A.; Dutreuil, Vincent; Laes, Agathe; Leymarie, Edouard; Malarde, Damien; Mangin, A.; Migon, Christophe; Morin, P.; Poteau, A.; Prieur, L.; Raimbault, P.; Testor, Pierre.
Tipo: Text
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00114/22555/20243.pdf

Sulfate minerals control dissolved rare earth element flux and Nd isotope signature of buoyant hydrothermal plume (EMSO-Azores, 37°N Mid-Atlantic Ridge)
Provedor de dados: 5
Autores: Chavagnac, Valerie; Ali, Hassan Saleban; Jeandel, Catherine; Leleu, Thomas; Destrigneville, Christine; Castillo, Alain; Cotte, Laura; Waeles, Mathieu; Cathalot, Cecile; Laes, Agathe; Pelleter, Ewan; Nonnotte, Philippe; Sarradin, Pierre-marie; Cannat, Mathilde.
While hydrothermal vents are now thought to be a major source of dissolved iron to the oceans, they have always been considered to be a sink for the dissolved rare-earth elements (DREEs). However, true dissolved REE observations in hydrothermal plumes are still lacking. Here we report for the first time the DREE concentrations and neodymium isotopic compositions (DεNd) of buoyant hydrothermal fluids at Lucky Strike (Mid-Atlantic Ridge). We find that 27 to 62% of total hydrothermal DREEs are rapidly scavenged by anhydrite precipitation at the onset of buoyant plume formation. After this initial loss, all DREEs behave quasi-conservatively within the buoyant plume. Dissolved phase εNd (DεNd) in the evolving plume are identical to black smoker DεNd of +9.0 and...
Tipo: Text
Palavras-chave: Black smokers; Rare earth elements; Neodymium isotopes; Hydrothermal; Sulfate minerals; EMSO-Azores.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00456/56733/58511.pdf