Consulta: creatorFacets:"Waeles, Mathieu"
Registros recuperados: 10
Data/hora: 05/06/2024 17:10:12

The Biogeochemistry of Electroactive Humic Substances and Its Connection to Iron Chemistry in the North East Atlantic and the Western Mediterranean Sea
Provedor de dados: 5
Autores: Dulaquais, Gabriel; Waeles, Mathieu; Gerringa, Loes J. A.; Middag, Rob; Rijkenberg, Micha J. A.; Riso, Ricardo.
We present the zonal distribution of electroactive humic-like substances (eHS) along a section from Offshore Portugal in the North East Atlantic to the Sicily Channel in the Mediterranean Sea. The concentrations were normalized to Suwannee River Fulvic Acid and ranged from 11g/L to 81g/L. The vertical distributions were typical of those previously reported for dissolved organic carbon in the Mediterranean Sea. High eHS concentrations were measured in surface water and concentrations decreased with depth before increasing again toward benthic maxima measured at some stations. We estimate that eHS represented a relatively small fraction of the natural organic matter in the Mediterranean Sea (2-5%) but considering their important role in the complexation and...
Tipo: Text
Palavras-chave: Humic substances; Iron; Mediterranean Sea; Biogeochemistry; GEOTRACES.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00616/72781/72218.pdf

Comparative study of potential transfer of natural and anthropogenic cadmium to plankton communities in the North-West African upwelling
Provedor de dados: 5
Autores: Auger, Pierre-amael; Machu, Eric; Gorgues, Thomas; Grima, Nicolas; Waeles, Mathieu.
A Lagrangian approach based on a physical-biogeochemical modeling was used to compare the potential transfer of cadmium (Cd) from natural and anthropogenic sources to plankton communities (Cd-uptake) in the NorthWest African upwelling. In this region, coastal upwelling was estimated to be the main natural source of Cd while the most significant anthropogenic source for marine ecosystem is provided by phosphate industry. In our model experiment, Cd-uptake (natural or anthropogenic) in the North-West African upwelling is the result of an interplay between the Cd dispersion (by advection processes) and the simulated biological productivity. In the Moroccan waters, advection processes limit the residence time of water masses resulting in a low natural...
Tipo: Text
Palavras-chave: Cadmium; North-West African upwelling; Phosphate industry; Dispersion; Bioaccumulation; Plankton ecosystem.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00252/36310/35200.pdf

A comparison of in situ vs. ex situ filtration methods on the assessment of dissolved and particulate metals at hydrothermal vents
Provedor de dados: 5
Autores: Cotte, Laura; Waeles, Mathieu; Pernet-coudrier, Benoit; Sarradin, Pierre-marie; Cathalot, Cecile; Riso, Ricardo D.
The objective of this study was to assess the impact of the filtration method (in situ vs. ex situ) on the dissolved/particulate partitioning of 12 elements in hydrothermal samples collected from the Lucky Strike vent field (Mid-Atlantic Ridge; MAR). To do so, dissolved ( &lt;0.45 mu m) and particulate Mg, Li, Mn, U, V, As, Ba, Fe, Zn, Cd, Pb and Cu were measured using different techniques (HR-ICP-MS, ICP-AES and CCSA). Using in situ filtration as a baseline, we showed that ex situ filtration (on-board and on shore after freezing) resulted in an underestimation of the dissolved pool, which was counterbalanced by an overestimation of the particulate pool for almost all the elements studied. We also showed that on-board filtration was acceptable for the...
Tipo: Text
Palavras-chave: Metal; Hydrothermal vent; Dissolved; Particulate; Filtration method.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00298/40970/42656.pdf

Comparative study of vent and seep macrofaunal communities in the Guaymas Basin
Provedor de dados: 5
Autores: Portail, Marie; Olu, Karine; Escobar-briones, E.; Caprais, Jean-claude; Menot, Lenaick; Waeles, Mathieu; Cruaud, Perrine; Sarradin, Pierre-marie; Godfroy, Anne; Sarrazin, Jozee.
Understanding the ecological processes and connectivity of chemosynthetic deep-sea ecosystems requires comparative studies. In the Guaymas Basin (Gulf of California, Mexico), the presence of seeps and vents in the absence of a biogeographic barrier, and comparable sedimentary settings and depths offers a unique opportunity to assess the role of ecosystem-specific environmental conditions on macrofaunal communities. Six seep and four vent assemblages were studied, three of which were characterised by common major foundation taxa: vesicomyid bivalves, siboglinid tubeworms and microbial mats. Macrofaunal community structure at the family level showed that density, diversity and composition patterns were primarily shaped by seep- and vent-common abiotic...
Tipo: Text
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00280/39076/37642.pdf

Sulfide determination in hydrothermal seawater samples using a vibrating gold micro-wire electrode in conjunction with stripping chronopotentiometry
Provedor de dados: 5
Autores: Aumond, Virginie; Waeles, Mathieu; Salaun, Pascal; Gibbon-walsh, Kristoff; Van Den Berg, Constant M. G.; Sarradin, Pierre-marie; Riso, Ricardo D.
A rapid electrochemical stripping chronopotentiometric procedure to determined sulfide in unaltered hydrothermal seawater samples is presented. Sulfide is deposited at -0.25 V (vs Ag/AgCl, KCl 3 M) at a vibrating gold microwire and then stripped through the application of a reductive constant current (typically -2 mu A). The hydrodynamic conditions are modulated by vibration allowing a short deposition step, which is shown here to be necessary to minimize H2S volatilization. The limit of detection (LOD) is 30 nM after a deposition step of 7s. This LOD is in the same range as the most sensitive cathodic voltammetric technique using a mercury drop electrode and is well below those reported previously for other electrodes capable of being implemented in situ....
Tipo: Text
Palavras-chave: Sulfide; Stripping chronopotentiometry; Vibrating electrode; Gold; Seawater; Hydrothermal.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00111/22222/20065.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

Cadmium in the waters off South Morocco: Nature of particles hosting Cd and insights into the mechanisms fractionating Cd from phosphate
Provedor de dados: 5
Autores: Waeles, Mathieu; Planquette, Helene; Afandi, Imane; Delebecque, Nina; Bouthir, Fatimazohra; Donval, Anne; Shelley, Rachel U.; Auger, Pierre-amael; Riso, Ricardo D.; De Morais, Luis Tito.
In this study, we report the distributions of total dissolvable cadmium and particulate cadmium from 27 stations in southern Moroccan coastal waters (22°N–30°N), which is part of the North-West African upwelling system. These distributions were predominantly controlled by upwelling of the North Atlantic Central Waters (NACWs) and uptake by primary production. Atmospheric inputs and phosphogypsum slurry inputs from the phosphate industry at Jorf Lasfar (33°N), recently estimated as an important source of dissolved cadmium (240 t Cd yr−1), are at best of minor importance for the studied waters. Our study provides new insights into the mechanisms fractionating cadmium from phosphate. In the upper 30 m, the anomalies observed in terms of Cd:P ratios in both...
Tipo: Text
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00334/44520/44216.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

On the early fate of hydrothermal iron at deep-sea vents: A reassessment after in situ filtration
Provedor de dados: 5
Autores: Waeles, Mathieu; Cotte, Laura; Pernet-coudrier, Benoit; Chavagnac, V.; Cathalot, Cecile; Leleu, T.; Laes-huon, Agathe; Perhirin, Antoine; Riso, R. D.; Sarradin, Pierre-marie.
Deep-sea hydrothermal venting is now recognized as a major source of iron (Fe), an essential trace element that controls marine productivity. However, the reactions occurring during dispersal from buoyant plumes to neutrally buoyant hydrothermal plumes are still poorly constrained. Here we report for the first time on the dissolved-particulate partition of Fe after in situ filtration at the early stage of mixing at different hydrothermal discharges, i.e., Lucky Strike (37 degrees N), TAG (26 degrees N), and Snakepit (23 degrees N) on the Mid-Atlantic Ridge. We found that hydrothermal iron is almost completely preserved (&gt;90%) in the dissolved fraction, arguing for low iron-bearing sulfide precipitation of iron in basalt-hosted systems with low Fe:H2S...
Tipo: Text
Palavras-chave: Hydrothermal; Iron; Sulfide; Venting; Filtration; Precipitation.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00388/49944/50522.pdf

An Integrated Biomarker Approach Using Flounder to Improve Chemical Risk Assessments in the Heavily Polluted Seine Estuary
Provedor de dados: 5
Autores: Borcier, Elodie; Charrier, Gregory; Couteau, Jérôme; Maillet, Géraldine; Le Grand, Fabienne; Bideau, Antoine; Waeles, Mathieu; Le Floch, Stephane; Amara, Rachid; Pichereau, Vianney; Laroche, Jean.
The objective of this study was to develop an integrative approach in ecotoxicology (from biomarkers to population genetics) to assess the ecological status of fish populations. Flounders (Platichthys flesus) collected after the spawning season in the heavily polluted Seine estuary were compared with the moderately polluted Bay of Douarnenez. The muscle energetic reserves were highly depleted in Seine vs. Douarnenez fish. The Seine fish displaying a reduced capacity to manage the oxidative stress and a higher energetic metabolism. An increase in the content of muscle membrane phospholipids (sphingomyelin, phosphatidylserine, free sterols) was detected in the Seine vs. Douarnenez fish. The data integration allowed to hypothesize relationships between...
Tipo: Text
Palavras-chave: Platichthys flesus; Estuaries; Biomarkers; Bioenergetics; Polar lipids; Population genetics.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00658/76981/78238.pdf