|
|
|
| Registros recuperados: 39 | |
|
|
| Khripounoff, Alexis; Sibuet, Myriam. |
| In deep waters, deposit-feeding holothurians represent a high percentage of the total abyssal biomass and play an important ecological role in sediment modification. The feeding of these organisms, which inhabit a nutritively poor environment, has been studied by means of analyses of intestinal contents. Four abundant species : Psychropotes longicauda Theel, Paroriza pallens (Koehler), Benthogone rosea Koehler and Molpadia blakei (Theel), collected between 2000 and 4500 m in the Bay of Biscay during three cruises organized by CNEXO-COB, were chosen for this study. The morphological characteristics of the ingested alimentary particles are described and the results of analyses of the organic matter in the guts reported. The species studied do not exhibit a... |
| Tipo: Text |
|
| Ano: 1980 |
URL: http://archimer.ifremer.fr/doc/1980/publication-5309.pdf |
| |
|
| |
|
|
| Riou, Virginie; Colaco, Ana; Bouillon, Steven; Khripounoff, Alexis; Dando, Paul; Mangion, Perrine; Chevalier, Emilie; Korntheuer, Michael; Santos, Raphael; Dehairs, Frank. |
| Bathymodiolus azoricus mussels thrive 840 to 2300 m deep at hydrothermal vents of the Azores Triple Junction on the Mid-Atlantic Ridge. Although previous studies have suggested a mixotrophic regime for this species, no analysis has yet yielded direct evidence for the assimilation of particulate material. In the present study, tracer experiments in aquaria with C-13- and N-15-labelled amino acids and marine cyanobacteria demonstrate for the first time the incorporation of dissolved and particulate organic matter in soft tissues of vent mussel. The observation of phytoplanktonic tests in wild mussel stomachs highlights the occurrence of in situ ingestion of sea-surface-derived material. Particulate organic carbon fluxes in sediment traps moored away from... |
| Tipo: Text |
Palavras-chave: Bathymodiolus azoricus; Particulate and dissolved material; Nitrogen and carbon assimilation; Deep sea; Hydrothermal vent; Mussel. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00005/11589/8230.pdf |
| |
|
|
| Mas, Virginie; Mulder, T.; Dennielou, Bernard; Schmidt, S.; Khripounoff, Alexis; Savoye, Bruno. |
| The Var turbidite system is a small sandy system located in the Ligurian Basin (Mediterranean Sea). It is active during present sea-level highstand and shows four types of sediment transfer processes: (1) low-density turbidity surges generated by small-scale failures (2) low-magnitude, high-frequency (yearly) hyperpycnal turbid plumes, (3) high-magnitude, less-frequent, hyperpycnal currents and (4) high-magnitude flows generated by large slope failures. These processes have different imprints on the morphology of the system. Inversely, the topography plays a role on the behaviour of these flows. The depositional and erosional architecture of the system has been investigated in detail on the basis of SAR imagery and a set of cores using an interface corer... |
| Tipo: Text |
Palavras-chave: Var; France; Gravity processes; Mediterranean; Turbidity current; Hyperpycnal; Flood. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12458/11862.pdf |
| |
|
|
| Heimbuerger, Lars-eric; Cossa, Daniel; Thibodeau, Benoit; Khripounoff, Alexis; Mas, Virginie; Chiffoleau, Jean-francois; Schmidt, Sabine; Migon, Christophe. |
| The magnitude and the chronology of anthropogenic impregnation by Hg and other trace metals of environmental concern (V, Cr, Ni, Cu, Zn, Ag, Cd and Pb, including its stable isotopes) in the sediments are determined at the DYFAMED station, a site in the Ligurian Sea (Northwestern Mediterranean) chosen for its supposed open-sea characteristics. The DYFAMED site (VD) is located on the right levee of the Var Canyon turbidite system, at the end of the Middle Valley. In order to trace the influence of the gravity current coming from the canyon on trace metal distribution in the sediment, we studied an additional sediment core (VA) from a terrace of the Var Canyon, and material collected in sediment traps at the both sites at 20 m above sea bottom. The patterns... |
| Tipo: Text |
Palavras-chave: Marine sediments; Sediment traps; Mercury; Trace metals; Lead isotopes; Geochronology. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00073/18435/16125.pdf |
| |
|
|
| Rabouille, C.; Caprais, Jean-claude; Lansard, B.; Crassous, Philippe; Dedieu, K.; Reyss, J. L.; Khripounoff, Alexis. |
| A study of organic carbon mineralization from the Congo continental shelf to the abyssal plain through the Congo submarine channel and Angola Margin was undertaken using in situ measurements of sediment oxygen demand as a tracer of benthic carbon recycling. Two measurement techniques were coupled on a single autonomous platform: in situ benthic chambers and microelectrodes, which provided total and diffusive oxygen uptake as well as oxygen microdistributions in porewaters. In addition, sediment trap fluxes, sediment composition (Org-C, Tot-N, CaCO3, porosity) and radionuclide profiles provided measurements of, respectively input fluxes and burial rate of organic and inorganic compounds. The in situ results show that the oxygen consumption on this margin... |
| Tipo: Text |
Palavras-chave: Sediment carbon budget; Organic carbon burial; Congo Submarine Canyon; Organic carbon recycling in sediments; In situ oxygen demand. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7316.pdf |
| |
|
|
| Khripounoff, Alexis; Vangriesheim, Annick; Crassous, Philippe; Segonzac, Michel; Colaco, Ana; Desbruyeres, Daniel; Barthelemy, Roxane. |
| In order to provide information about the export and the distribution of hydrothermal particulate material to the surrounding deep ocean, four moorings were deployed in the vicinity of the hydrothermal Rainbow vent field (Mid-Atlantic Ridge, 36 degrees 14'N, 2250 m depth). The first mooring was a sediment trap with a current meter deployed at 2 m from a chimney of the Rainbow vent field and 1.5 m above the bottom (a.b.) for 16 days. It represented the reference for the initial composition of particles produced by the vent. The total mean mass particle flux (6.9 g m(-2) d(-1)) was distinctly higher than the flux measured at the shallower hydrothermal vents on the MAR segment. This particulate flux showed a high temporal variation at the scale of a few days... |
| Tipo: Text |
Palavras-chave: Zooplankton; Biochemistry; Geochemistry; Particle flux; Hydrothermal vent. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/2001/publication-801.pdf |
| |
|
| |
|
|
| Raimonet, Melanie; Ragueneau, Olivier; Jacques, Vincent; Corvaisier, Rudolph; Moriceau, Brivaela; Khripounoff, Alexis; Pozzato, Lara; Rabouille, Christophe. |
| Mechanisms controlling the transfer and retention of silicon (Si) along continental margins are poorly understood, but play a major role in the functioning of coastal ecosystems and the oceanic biological pump of carbon. Deep-sea fans are well recognized as carbon sink spots, but we lack knowledge about the importance of the fans in the global Si cycle. Here, we provide a first estimate of the role played by the Congo deep-sea fan, one of the biggest in the world, in the Si cycle. Sediment cores sampled in the deep-sea fan were analyzed to build a Si mass balance. An exceptionally high accumulation rate of amorphous silica aSiO(2) (2.29 +/- 0.58 mol Si m(-2) y(-1)) was found, due to a high sedimentation rate and the presence of aluminum in the sediments.... |
| Tipo: Text |
Palavras-chave: Continental margin; Land-sea export; Silica cycle; Congo canyon; Deep-sea fan. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00251/36242/35797.pdf |
| |
|
|
| Freslon, Nicolas; Bayon, Germain; Toucanne, Samuel; Bermell, Sylvain; Bollinger, Claire; Chéron, Sandrine; Etoubleau, Joel; Germain, Yoan; Khripounoff, Alexis; Ponzevera, Emmanuel; Rouget, Marie Laure. |
| We report rare earth element (REE) and neodymium (Nd) isotope data for the organic fraction of sediments collected from various depositional environments, i.e. rivers (n=25), estuaries (n=18), open-ocean settings (n=15), and cold seeps (n=12). Sedimentary Organic Matter (SOM) was extracted using a mixed hydrogen peroxide/nitric acid solution (20%-H2O2 – 0.02M-HNO3), after removal of carbonate and oxy-hydroxide phases with dilute hydrochloric acid (0.25M-HCl). A series of experimental tests indicate that extraction of sedimentary organic compounds using H202 may be complicated occasionally by partial dissolution of sulphide minerals and residual carbonates. However, this contamination is expected to be minor for REE because measured concentrations in H2O2... |
| Tipo: Text |
Palavras-chave: Organic matter; Rare earth elements; REE; Neodymium isotopes; ΕNd; Sediment; Boundary Exchange; Paleoceanography. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00191/30250/28682.pdf |
| |
|
|
| Crassous, Philippe; Khripounoff, Alexis; Larosa, Jacques; Miquel, Juan-carlos. |
| Four sediment traps of two different types and two current meters were deployed fixed to two identical moorings, at a depth of 2 000 m, off the coast at Nice, for 70 days between April and June 1987. The particulate flux measured with sediment traps decreased from 1 000 to 95 mg/m2/day during this experiment. The carbonate carbon concentration of the particles also decreased during this period; organic carbon concentrations varied inversely with the flux, increasing from 1.8 to 3.7 % of the particle dry weight. It is concluded that these changes reveal the presence of a deep-sea storm with a significant resuspension of sediment to a height greater than 200 m (distance of the traps from the bottom). By the end of the experiment, identical sediment traps had... |
| Tipo: Text |
|
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00101/21244/18859.pdf |
| |
|
|
| Khripounoff, Alexis; Caprais, Jean-claude; Decker, Carole; Le Bruchec, J.; Noel, Philippe; Husson, Berengere. |
| We studied bivalves (vesicomyids and mytilids) inhabiting four different areas of high sulfide and methane production: 1) in the Gulf of Guinea, two pockmarks (650 m and 3150 m depth) and one site rich in organic sediments in the deepest zone (4950 m average depth), 2) at the Azores Triple Junction on the Mid-Atlantic Ridge, one hydrothermal site (Lucky Strike vent field, 1700 m depth). Two types of Calmar benthic chambers were deployed, either directly set into the sediment (standard Calmar chamber) or fitted with a tank to isolate organisms from the sediment (modified Calmar chamber), to assess gas and solute exchanges in relation to bivalve bed metabolism. Fluxes of oxygen, total carbon dioxide, ammonium and methane were measured. At the site with... |
| Tipo: Text |
Palavras-chave: Deep-sea; Benthic chamber; Vesicomyid and Mytilid bivalves; Respiration rate; Cold seep; Hydrothermal vent. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00341/45204/44614.pdf |
| |
|
|
| Galeron, Joelle; Menot, Lenaick; Renaud, Nolwenn; Crassous, Philippe; Khripounoff, Alexis; Treignier, C.; Sibuet, M.. |
| Density, taxonomic composition at higher taxon level and vertical distribution of benthic macrofaunal communities and sediment characteristics (pore water, nitrogen, organic carbon, sulfur, C/N ratio, n-alcohol biomarkers) were examined at three deep sites on the Congo-Gabon continental margin. This study was part of the multidisciplinary BIOZAIRE project that aimed at studying the deep benthic ecosystems in the Gulf of Guinea. Sampling of macrofaunal communities and of sediment was conducted during three cruises (January 2001, December 2001 and December 2003) at two downslope sites (4000 m depth), one located near the Congo submarine channel (15 km in the south) and the other one far from the channel (150km in the South). The third area located 8 km north... |
| Tipo: Text |
Palavras-chave: Deep sea; Distribution; Community structure; Macrofauna; Congo canyon; Congo Angola margin; Equatorial west Africa margin; Atlantic. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7315.pdf |
| |
|
|
| Menot, Lenaick; Galeron, Joelle; Olu, Karine; Caprais, Jean-claude; Crassous, Philippe; Khripounoff, Alexis; Sibuet, Myriam. |
| The structure and familial-level composition of macrofaunal communities were examined within and at distance from the giant pockmark Regab in the Southern Gulf of Guinea, at 3200 m depth. The two main questions addressed in this study were (i) does habitat partitioning by large symbiont-bearing taxa. influence macrofaunal assemblages and their environment? and (ii) to what extent does the chemosynthesis-based ecosystem influence the structure and the composition of nearby macrobenthic communities? Along two radials, at sites from 250 to 1000 m away from the active centre of the cold seep, the abundance and composition of the macrofauna were typical of a deep-sea community at that depth. Except for a few cores sampled in or near dead vesicomyid fields at... |
| Tipo: Text |
Palavras-chave: Cold seep; Diversity; Gulf of Guinea; Habitat heterogeneity; Macrofauna; Open slope; Siboglinid tubeworms; Vesicomyid clams. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00002/11282/8099.pdf |
| |
|
|
| Khripounoff, Alexis; Vangriesheim, Annick; Crassous, Philippe; Segonzac, Michel; Lafon, V; Waren, A. |
| In order to provide information on the production and the distribution of hydrothermal particulate and biological material produced by deep-sea hydrothermal vents, three moorings with sediment traps and currentmeters were deployed for one year in the Azores Triple Junction region. Two moorings were positioned close to two hydrothermal vent fields at the Mid-Atlantic Ridge (Rainbow, 36 degrees 14'N, 33 degrees 54'W, 2250 in depth and Lucky Strike 37 degrees 17'N, 32 degrees 17'W, 1600 in depth). A third was moored out of the influence of the Rainbow vents representing the reference of the pelagic flux in this area. At the Rainbow field, particulate flux (range 341-634 g m(-2)d(-1)) showed a high temporal variation controlled essentially by the current... |
| Tipo: Text |
Palavras-chave: Bivalve reproduction; Bivalve larvae; Particle composition; Particle flux; Currents; Deep sea hydrothermal vents. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4059.pdf |
| |
|
|
| Rabouille, C.; Olu, Karine; Baudin, F.; Khripounoff, Alexis; Dennielou, Bernard; Arnaud-haond, Sophie; Babonneau, Nathalie; Bayle, Christophe; Beckler, J.; Bessette, Sandrine; Bombled, B.; Bourgeois, S.; Brandily, Christophe; Caprais, Jean-claude; Cathalot, Cecile; Charlier, K.; Corvaisier, R.; Croguennec, Chantal; Cruaud, Perrine; Decker, Carole; Droz, L.; Gayet, Nicolas; Godfroy, Anne; Hourdez, S.; Le Bruchec, J.; Saout, Johan; Le Saout, Marie-helene; Lesongeur, Francoise; Martinez, P.; Mejanelle, L.; Michalopoulos, P.; Mouchel, Olivier; Noel, Philippe; Pastor, Lucie; Picot, M.; Pignet, Patricia; Pozzato, L.; Pruski, A. M.; Rabiller, Manuella; Raimonet, M.; Ragueneau, O.; Reyss, J. L.; Rodier, Philippe; Ruesch, Blandine; Ruffine, Livio; Savignac, F.; Senyarich, C.; Schnyder, J.; Sen, Arunima; Stetten, E.; Sun, Ming Yi; Taillefert, M.; Teixeira, S.; Tisnerat-laborde, N.; Toffin, Laurent; Tourolle, Julie; Toussaint, F.; Vetion, G.; Jouanneau, J. M.; Bez, M.. |
| The presently active region of the Congo deep-sea fan (around 330 000 km2), called the terminal lobes or lobe complex, covers an area of 2500 km2 at 4700–5100 m water depth and 750–800 km offshore. It is a unique sedimentary area in the world ocean fed by a submarine canyon and a channel-levee system which presently deliver large amounts of organic carbon originating from the Congo River by turbidity currents. This particularity is due to the deep incision of the shelf by the Congo canyon, up to 30 km into the estuary, which funnels the Congo River sediments into the deep-sea. The connection between the river and the canyon is unique for major world rivers. In 2011, two cruises (WACS leg 2 and Congolobe) were conducted to simultaneously investigate the... |
| Tipo: Text |
Palavras-chave: Chemosynthetic habitats; Congo deep-sea fan; Fine sediment; Sedimentation rate; Seafloor morphology; Turbidite; Vesicomyidae. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00335/44580/44298.pdf |
| |
|
| |
|
|
| Khripounoff, Alexis; Caprais, Jean-claude; Decker, Carole; Essirard, Mikael; Le Bruchec, Julie; Noel, Philippe; Olu, Karine. |
| We have studied two species of vesicomyid bivalves inhabiting different areas of sulfide-rich sediments in association with methane seepage at two pockmarks located at about 650 m and 3150 m depth, respectively, along the Gabon-Congo margin, and organic-rich sediments in the deepest zone (4950 m depth) of the Congo deep-sea fan. Benthic chambers Calmar were deployed on three study sites to assess gas and solute exchanges at the water-sediment interface. We recorded in situ measurements of oxygen, total carbon dioxide, ammonium, methane, and sulfide in two clam beds at each site. At all sites, irrespective of which the vesicomyid species are present, oxygen consumption was high and variable (28–433 mmol m−2 d−1) as was total carbon dioxide emission (36–1857... |
| Tipo: Text |
Palavras-chave: Benthic chamber; Cold-seep ecosystem; Reduced sediment; Gas fluxes; Vesicomyid bivalves; Gulf of Guinea. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00226/33746/32160.pdf |
| |
|
|
| Crassous, Philippe; Khripounoff, Alexis. |
| Nine sediment traps were assembled in triplicate on a frame and deployed at 100 m above the bottom in the California abyssal plain (4 100 m depth) for ten days. The distances between traps were from 30 cm to 11 km. The main flux measured during this period was 167 mg m(-2) day(-1) with a minimum of 43 mg m(-2) d(-1) and a maximum of 283 mg m(-2) d(-1). This high variation of the particulate flux at the kilometric scale was also observed at a metric scale: for example, the particulate flux measured with one of triplicate traps was equal to 82.3 +/- 46.5 mg m(-2) d(-1) (more than 50 % of variation) between traps distant of less than 1 m. To explain this heterogeneity of the flux measurement, some hypotheses are developed in this study: sampling artefact,... |
| Tipo: Text |
Palavras-chave: SEDIMENT TRAPS; DEEP SEA; HORIZONTAL FLUX VARIATION. |
| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00098/20885/18499.pdf |
| |
| Registros recuperados: 39 | |
|
|
|
