A5005045830- Marine and coastal ecosystems
- Marine Biology and Ecology Research
- Geochemistry and Elemental Analysis
- Heavy metals in environment
- Ocean Acidification Effects and Responses
- Mercury impact and mitigation studies
- Microbial Community Ecology and Physiology
- Atmospheric chemistry and aerosols
- Oceanographic and Atmospheric Processes
- Radioactive contamination and transfer
- Isotope Analysis in Ecology
- Groundwater and Isotope Geochemistry
- Geochemistry and Geologic Mapping
- Radioactivity and Radon Measurements
- Paleontology and Stratigraphy of Fossils
- Vehicle emissions and performance
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Climate Change and Geoengineering
- Atmospheric and Environmental Gas Dynamics
- Environmental Toxicology and Ecotoxicology
- Coastal and Marine Management
- Chemical Synthesis and Characterization
- Aeolian processes and effects
- Iron oxide chemistry and applications
Sorbonne Université
2013-2024
Laboratoire d’Océanographie de Villefranche
2013-2024
Centre National de la Recherche Scientifique
2012-2024
Centre National pour la Recherche Scientifique et Technique (CNRST)
2024
Institut de la Mer de Villefranche
2023
University of Tasmania
2014-2023
Institute for Marine and Antarctic Studies
2014-2021
Université de Toulon
2021
Aix-Marseille Université
2021
Commonwealth Scientific and Industrial Research Organisation
2021
Iron is an essential nutrient that regulates productivity in ~30% of the ocean. Compared with deep (>2000 meter) hydrothermal activity at mid-ocean ridges provide iron to ocean's interior, shallow (<500 fluids are likely influence surface's ecosystem. However, their effect unknown. In this work, we show emitted along Tonga volcanic arc (South Pacific) have a substantial impact on concentrations photic layer through vertical diffusion. This enrichment stimulates biological activity, resulting...
Abstract Biological N 2 fixation rates were quantified in the Eastern Tropical South Pacific (ETSP) during both El Niño (February 2010) and La Niña (March–April 2011) conditions, from Low‐Nutrient, Low‐Chlorophyll (20°S) to High‐Nutrient, (HNLC) (10°S) conditions. was detected at all stations with ranging 0.01 0.88 nmol L −1 d , higher measured conditions compared Niña. High fixations reported northern (HNLC conditions) oxycline oxygen minimum zone (OMZ), despite nitrate concentrations up 30...
Abstract. Lithogenic particles, such as desert dust, have been postulated to influence particulate organic carbon (POC) export the deep ocean by acting mineral ballasts. However, an accurate understanding and quantification of POC–dust association that occurs within upper is required in order refine "ballast hypothesis". In framework DUNE (a DUst experiment a low-Nutrient, low-chlorophyll Ecosystem) project, two artificial seedings were performed seven days apart large mesocosms. A suite...
Abstract Abiotic iron removal processes such as scavenging can significantly and rapidly modify distribution in the dissolved‐colloidal‐particulate continuum. Therefore, these could be considered, addition to ligand complexation, a major control on atmospheric dissolution seawater. In this work, we investigated seasonal abiotic occurring once dust deposited surface seawater using series of artificial seeding experiments (allowing us take into consideration settling particles 1 m depth...
Abstract. By bringing new nutrients and particles to the surface ocean, atmospheric deposition impacts biogeochemical cycles. The extent which those changes are modifying carbon balance in oligotrophic environments such as Mediterranean Sea that receives important Saharan dust fluxes is unknown. DUNE (DUst experiment a low Nutrient, chlorophyll Ecosystem) project provides first attempt evaluate induced budget of large body waters after simulated wet or dry events, allowing us measure (1)...
Abstract. The deposition of atmospheric dust is the primary process supplying trace elements abundant in crustal rocks (e.g. Al, Mn and Fe) to surface ocean. Upon deposition, residence time waters for each these differs according their chemical speciation biological utilization. Presently however behavior after poorly constrained, principally because difficulty following natural events in-situ. In present work we examined temporal changes biogeochemistry metals (in particular an artificial...
Abstract. The Sea Surface Microlayer (SML) is known to be enriched by trace metals relative the underlying water and harbor diverse microbial communities (i.e., neuston). However, processes linking biota in SML are not yet fully understood. metal (Cd, Co, Cu, Fe, Ni, Mo, V, Zn Pb) concentrations aerosol samples (dissolved total fractions) subsurface waters (SSWs; dissolved fraction at ∼1 m depth) from western Mediterranean were analyzed this study during a cruise May–June 2017. composition...
Iron (Fe) is an essential micronutrient for phytoplankton growth, but its scarcity in seawater limits primary productivity across much of the ocean. Most dissolved Fe (DFe) complexed with Fe-binding organic ligands, a poorly constrained fraction matter (DOM), which increase residence time and impact bioavailability. Here, we present conditional concentration (L ) binding-strength (log <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"...
The passive sinking flux of particles, termed the biological gravitational pump (BGP), is an important component ocean’s carbon pump. In addition, carbon-rich particles are actively injected to depth through diel vertical migration (DVM) micronekton and mesozooplankton from surface oceans’ twilight zone (200 m – 1000 depth). This known as mesopelagic-migrant (MMP). We investigated magnitude MMP at one subantarctic two polar sites in summer by assessing particulate dissolved export below 200...
Wildfires contribute significantly to biomass burning. The deposition of ash from wildfires into surface ocean waters is a source iron (Fe), namely pyrogenic Fe, and may enhance primary production in Fe-limited domains. However, due the low solubility Fe operational definition its dissolved fraction, portion (DFe) released during dissolution reprecipitate as authigenic inorganic colloids. This process can lead an overestimation bioavailable DFe. To remain soluble form, must be complexed with...
Over recent decades, the Mediterranean basin has faced enhanced wildfire risks due to longer dry seasons and higher temperatures associated with global changes. Wildfire-generated aerosols could travel long distances ultimately end in ocean, where they may subsequently impact marine microbial communities that are key drivers of geochemical cycles. However, current knowledge about influence ash on abundance composition microbes remains limited. We conducted experiments surface seawater from...
Iron (Fe) is a paradox in the modern ocean—it central to many life-critical enzymes but scarce across most surface waters. The high cellular demand and low bioavailability of Fe likely puts selective pressure on marine microorganisms. Previous observations suggest that heterotrophic bacteria are outcompeted by small diatoms for supply SubAntarctic Zone Southern Ocean, thereby challenging idea being more competitive than phytoplankton access this trace metal. To test hypothesis, incubation...
Abstract In the Western Tropical South Pacific, a hotspot of dinitrogen‐fixing organisms has been identified. The survival these species depends on availability dissolved iron (DFe); however, source this DFe is still unclear. was measured along transect from 175°E to 166°W near 19–21°S. distribution showed high spatial variability: low concentrations (∼0.2 nmol kg −1 ) in Pacific gyre and (up 50 west Tonga arc, indicating that arc clear boundary between iron‐poor iron‐rich waters. An optimal...
Abstract Iron is a key micronutrient in seawater, but concentrations would be negligible without the presence of organic ligands. The processes influencing ligand pool composition are poorly constrained, limiting our understanding controls on dissolved iron distributions. To address this, release and iron‐binding ligands during microbial remineralization sinking particles was investigated by deploying situ particle interceptor/incubator devices at subsurface sites Mediterranean Sea...
Abstract. This study reports the only recent characterization of two contrasted wet deposition events collected during PEACETIME (ProcEss studies at Air–sEa Interface after dust in MEditerranean Sea) cruise open Mediterranean Sea (Med and their impact on trace metal (TM) marine stocks. Rain samples were analysed for Al, 12 TMs (Co, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Ti, V Zn) nutrient (N, P, dissolved organic carbon) concentrations. The first rain sample Ionian (Rain ION) was a typical regional...
Abstract. Mineral dust deposition is an important supply mechanism for trace elements in the low-latitude ocean. Our understanding of controls such inputs has been mostly built onto laboratory and surface ocean studies. The lack direct observations tendency to focus on near waters prevent a comprehensive evaluation role oceanic biogeochemical cycles. In frame PEACETIME project (ProcEss studies at Air-sEa Interface after MEditerranean sea), responses aluminium (Al) iron (Fe) cycles two wet...
Abstract. Mineral dust deposition is an important supply mechanism for trace elements in the low-latitude ocean. Our understanding of controls such inputs has been mostly built on laboratory and surface ocean studies. The lack direct observations tendency to focus near-surface waters prevent a comprehensive evaluation role oceanic biogeochemical cycles. In frame PEACETIME project (ProcEss studies at Air-sEa Interface after MEditerranean sea), responses aluminum (Al) iron (Fe) cycles two wet...
Abstract. Lithogenic elements such as aluminum (Al), iron (Fe), rare earth (REEs), thorium (232Th and 230Th, given Th) protactinium (Pa) are often assumed to be insoluble. In this study, their dissolution from Saharan dust reaching Mediterranean seawater was studied through tank experiments over 3 4 d under controlled conditions including controls without addition well seeding present future climate (+3 ∘C −0.3 pH). Unfiltered surface three oligotrophic regions (Tyrrhenian Sea, Ionian Sea...