Consulta: creatorFacets:"Radakovitch, Olivier"
Registros recuperados: 8
Data/hora: 05/06/2024 08:12:39

Patterns of trace metal bioaccumulation and trophic transfer in a phytoplankton-zooplankton-small pelagic fish marine food web
Provedor de dados: 5
Autores: Chouvelon, Tiphaine; Strady, Emilie; Harmelin-vivien, Mireille; Radakovitch, Olivier; Brach-papa, Christophe; Crochet, Sylvette; Knoery, Joel; Rozuel, Emmanuelle; Thomas, Bastien; Tronczynski, Jacek; Chiffoleau, Jean-francois.
Trace metal contamination in the European sardine and anchovy food web was investigated in the Gulf of Lions, NW Mediterranean Sea, including seawater and size fractions of plankton. The results highlighted: i) higher and more variable concentrations in the smaller plankton size classes for all metals except cadmium; ii) higher concentrations in anchovy versus sardine for all elements except lead; iii) different patterns of metal bioaccumulation through the food web: cobalt, nickel, copper, silver, lead and zinc displayed continuously decreasing concentrations (with the exception of increased zinc in fish only), while mercury concentrations dropped considerably in larger plankton size classes and rose significantly in fish. Lastly, cadmium concentrations...
Tipo: Text
Palavras-chave: Inorganic elements; Seawater; Size-classed plankton; Sardina pilchardus; Engraulis encrasicolus; Mediterranean Sea.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00511/62286/67906.pdf

Nutrient Fluxes Associated With Submarine Groundwater Discharge From Karstic Coastal Aquifers (Côte Bleue, French Mediterranean Coastline)
Provedor de dados: 5
Autores: Bejannin, Simon; Tamborski, Joseph James; Van Beek, Pieter; Souhaut, Marc; Stieglitz, Thomas; Radakovitch, Olivier; Claude, Christelle; Conan, Pascal; Pujo-pay, Mireille; Crispi, Olivier; Le Roy, Emilie; Estournel, Claude.
Determination of submarine groundwater discharge (SGD) from karstic coastal aquifers is important to constrain hydrological and biogeochemical cycles. However, SGD quantification using commonly employed geochemical methods can be difficult to constrain under the presence of large riverine inputs, and is further complicated by the determination of the karstic groundwater endmember. Here, we investigated a coastal region where groundwater discharges from a karstic aquifer system using airborne thermal infrared mapping and geochemical sampling conducted along offshore transects. We report radium data (223Ra, 224Ra, 228Ra) that we used to derive fluxes (water, nutrients) associated with terrestrial groundwater discharge and/or seawater circulation through the...
Tipo: Text
Palavras-chave: Submarine groundwater discharge; Mediterranean sea; Radium isotopes; Thermal infrared remote sensing; Nutrient fluxes; GEOTRACES.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00610/72171/70945.pdf

Modeling the Influence of Eutrophication and Redox Conditions on Mercury Cycling at the Sediment-Water Interface in the Berre Lagoon
Provedor de dados: 5
Autores: Pakhomova, Svetlana; Yakushev, Evgeniy; Protsenko, Elizaveta; Rigaud, Sylvain; Cossa, Daniel; Knoery, Joel; Couture, Raoul-marie; Radakovitch, Olivier; Yakubov, Shamil; Krzeminska, Dominika; Newton, Alice.
This study presents a specifically designed Mercury module in a coupled benthic-pelagic reactive-transport model - Bottom RedOx Model (BROM) that allows to study mercury (Hg) biogeochemistry under different conditions. This module considers the transformation of elemental mercury (Hg(0)), divalent mercury (Hg(II)) and methylmercury (MeHg). The behavior of mercury species in the model is interconnected with changes of oxygen, hydrogen sulfide, iron oxides, organic matter, and biota. We simulated the transformation and transport of Hg species in the water column and upper sediment layer under five different scenarios, combining various levels of oxygenation and trophic state in the Berre lagoon, a shallow eutrophic lagoon of the French Mediterranean coast...
Tipo: Text
Palavras-chave: Mercury; Methylmercury; Biogeochemical modeling; Anoxia; Eutrophication; Lagoon; BROM.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00454/56535/58239.pdf

MESURHO : a high frequency oceanographic buoy at the Rhone River mouth
Provedor de dados: 5
Autores: Cadiou, Jean-francois; Repecaud, Michel; Arnaud, Mireille; Rabouille, Christophe; Raimbault, Patrick; Radakovitch, Olivier; Meule, Samuel; Gaufres, Pierre; Pairaud, Ivane.
As the current main source of continental fresh water discharge in the Mediterranean Sea, the Rhone River inputs are a key forcing for ecosystems of the Gulf of Lions in the western basin. In order to better characterize the exchanges at this key interface, an oceanographic buoy has been installed at the Rhone River mouth in June 2009 for high frequency multiparameter measurements with bottom, water column and air sensors. Data are sent in near real time towards an onshore data center.
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00070/18161/15718.pdf

Origin and Accumulation of Trace Elements in Sediments of the Northwestern Mediterranean Margin
Provedor de dados: 5
Autores: Cossa, Daniel; Buscail, R.; Puig, P.; Chiffoleau, Jean-francois; Radakovitch, Olivier; Jeanty, G.; Heussner, S.
Continental margins receive natural and anthropogenic trace elements (TEs) from direct atmospheric deposition of aerosols onto the sea surface and from advection of riverine suspended particles and/or resuspended sediments from the continental shelf/slope. When the margin is incised by submarine canyons, as for example in the Northwestern Mediterranean Sea, most of these particles are preferentially transferred via these topographic features towards their final repositories in the abyssal plain. The Gulf of Lions (GoL) shelf receives the largest particulate riverine input to the Western Mediterranean, with its associated chemical contaminants originating from the industrialized and urbanized Rhone Valley. Sediments samples (grabs, cores and moored traps)...
Tipo: Text
Palavras-chave: Trace-element; Sediment; Canyon; Continental margin; Mediterranean.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00188/29971/28424.pdf

210Po and 210Pb trophic transfer within the phytoplankton–zooplankton–anchovy/sardine food web: a case study from the Gulf of Lion (NW Mediterranean Sea)
Provedor de dados: 5
Autores: Strady, Emilie; Harmelin-vivien, Mireille; Chiffoleau, Jean-francois; Veron, Alain; Tronczynski, Jacek; Radakovitch, Olivier.
The transfer of 210Po and 210Pb in the food web of small pelagic fishes (from phytoplankton and zooplankton to anchovy Engraulis encrasicolus and sardine Sardina pilchardus) is investigated in the Gulf of Lion (GoL). We present original data of 210Po and 210Pb activity concentrations, C and N stable isotope ratios, measured (i) from different size classes of phytoplankton and zooplankton during spring and winter in different environments of the GoL, and (ii) in two fish species. Significant spatial patterns based on 210Po, 210Pb activity concentrations and 210Po/210Pb ratios in the different plankton size classes are evidenced by hierarchical clustering, both in spring and winter. This variability, also observed for C and N stable isotopes ratios, is...
Tipo: Text
Palavras-chave: Po-210; Pb-210; Phytoplankton; Zooplankton; Pelagic fishes; Mediterranean Sea.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00255/36609/35264.pdf

Unexpected biotic resilience on the Japanese seafloor caused by the 2011 Tohoku-Oki tsunami
Provedor de dados: 5
Autores: Toyofuku, Takashi; Duros, Pauline; Fontanier, Christophe; Mamo, Briony; Bichon, Sabrina; Buscail, Roselyne; Chabaud, Gerard; Deflandre, Bruno; Goubet, Sarah; Gremare, Antoine; Menniti, Christophe; Fujii, Minami; Kawamura, Kiichiro; Koho, Karoliina Annika; Noda, Atsushi; Namegaya, Yuichi; Oguri, Kazumasa; Radakovitch, Olivier; Murayama, Masafumi; De Nooijer, Lennart Jan; Kurasawa, Atushi; Ohkawara, Nina; Okutani, Takashi; Sakaguchi, Arito; Jorissen, Frans; Reichart, Gert-jan; Kitazato, Hiroshi.
On March 11th, 2011 the Mw 9.0 2011 Tohoku-Oki earthquake resulted in a tsunami which caused major devastation in coastal areas. Along the Japanese NE coast, tsunami waves reached maximum run-ups of 40 m, and travelled kilometers inland. Whereas devastation was clearly visible on land, underwater impact is much more difficult to assess. Here, we report unexpected results obtained during a research cruise targeting the seafloor off Shimokita (NE Japan), shortly (five months) after the disaster. The geography of the studied area is characterized by smooth coastline and a gradually descending shelf slope. Although high-energy tsunami waves caused major sediment reworking in shallow-water environments, investigated shelf ecosystems were characterized by...
Tipo: Text
Palavras-chave: Palaeoceanography; Biodiversity.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00248/35914/34453.pdf

Mobility and fluxes of trace elements and nutrients at the sediment-water interface of a lagoon under contrasting water column oxygenation conditions
Provedor de dados: 5
Autores: Rigaud, Sylvain; Radakovitch, Olivier; Couture, Raoul-marie; Deflandre, Bruno; Cossa, Daniel; Garnier, Cedric; Garnie, Jean-marie.
The early diagenesis of the major carrier phases (Fe and Mn minerals), trace elements (As, Co, Cr, Hg, MeHg, Ni) and nutrients (Sigma NO3, NH4+, Sigma PO4) and their exchange at the sediment water/interface were studied in the Berre Lagoon, a Mediterranean lagoon in France, at one site under two contrasting oxygenation conditions (strictly anoxic and slightly oxic) and at an adjacent site with perennially well-oxygenated water. From the concentration profiles of the primary biogeochemical constituents and trace elements of the pore and bottom waters, as well as the total and reactive particulate phases, it was possible to locate and identify the diagenetic reactions controlling the mobility of trace elements in the sediments and quantify their rates by...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00134/24555/23573.pdf