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| Registros recuperados: 10 | |
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| Fontanier, Christophe; Mamo, Briony; Toucanne, Samuel; Bayon, Germain; Schmidt, Sabine; Deflandre, Bruno; Dennielou, Bernard; Jouet, Gwenael; Garnier, Eline; Sakai, Saburo; Lamas, Ruth Martinez; Duros, Pauline; Toyofuku, Takashi; Sale, Aurelien; Belleney, Deborah; Bichon, Sabrina; Boissier, Audrey; Cheron, Sandrine; Pitel, Mathilde; Roubi, Angelique; Rovere, Mickael; Gremare, Antoine; Dupre, Stephanie; Jorry, Stephan. |
| In this short communication, we present a multidisciplinaty study of sedimentary records collected from a deep-sea interfluve proximal to the mouths of major northwestern Madagascan rivers. For the last 60 years, the seafloor has been repeatedly disturbed by the deposition of organic rich, tropical, terrestrial sediments causing marked reductions in benthic biodiversity. Increased soil erosion due to local land-use, deforestation and intensifying tropical cyclones are potential causes for this sedimentary budget and biodiversity shift. Our marine sedimentary records indicate that until now, these conditions have not occurred within the region for at least 20,000 years. |
| Tipo: Text |
Palavras-chave: Multidisciplinary study; Benthic foraminifera; Land-use; Tropical cyclones. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00413/52488/53276.pdf |
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| Fontanier, Christophe; Koho, K. A.; Goni-urriza, M. S.; Deflandre, Bruno; Galaup, S.; Ivanovsky, A.; Gayet, Nicolas; Dennielou, Bernard; Gremare, Antoine; Bichon, S.; Gassie, C.; Anschutz, P.; Duran, R.; Reichart, G. J.. |
| We present ecological and isotopic (δ18O and δ13C) data on benthic foraminifera sampled from 4 deep-sea stations in a pockmark field from the deep-water Niger delta (Gulf of Guinea, Equatorial Atlantic Ocean). In addition, a series of sedimentological and (bio)geochemical data are shown to back up foraminiferal observations. All stations are located within 1.2 km of each other, so prevailing oceanographic conditions can be assumed to be similar at each site. Two of the sites (GMMC-01 and GMMC-02) are located in a pockmark (named “pockmark A”) where current methane seepages were recorded by ROV observations. A third station (GMMC-03) is located in the topographic depression interpreted as a collapsed pockmark (named “pockmark B”). The fourth site (GMMC-04)... |
| Tipo: Text |
Palavras-chave: Niger delta; Hydrate pockmark; Foraminifera; Stable isotopes; Bacteria. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00211/32194/30628.pdf |
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| Bernard, Guillaume; Romero-ramirez, Alicia; Tauran, Adeline; Pantalos, Michael; Deflandre, Bruno; Grall, Jacques; Gremare, Antoine. |
| Maerl beds form complex biogenic benthic habitats, characterized by high productivity as well as diverse biological communities. Disturbances associated with extraction and/or fishing activities using mobile bottom-contacting gears such as clam-dredges induce the most severe and long-term effects on these fragile habitats. We here investigated the effects of dredge-fishing on maerl in the bay of Brest (France). We quantified maerl beds structure and vitality across a fine scale quantified dredging intensity gradient through the acquisition of in-situ images of beds cross-section using Sediment Profile Imaging system (SPI). Declines in the proxies of maerl vitality and habitat complexity were measured across the gradient, and were associated with... |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00677/78861/81162.pdf |
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| Bernard, Guillaume; Duchene, Jean-claude; Romero-ramirez, Alicia; Lecroart, Pascal; Maire, Olivier; Ciutat, Aurelie; Deflandre, Bruno; Gremare, Antoine. |
| The effects of temperature and food addition on particle mixing in the deposit-feeding bivalve Abra alba were assessed using an experimental approach allowing for the tracking of individual fluorescent particle (luminophore) displacements. This allowed for the computations of vertical profiles of a set of parameters describing particle mixing. The frequency of luminophore displacements (jumps) was assessed through the measurement of both waiting times (i.e., the time lapses between two consecutive jumps of the same luminophore) and normalized numbers of jumps (i.e., the numbers of jumps detected in a given area divided by the number of luminophores in this area). Jump characteristics included the direction, duration and length of each jump. Particle... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00375/48615/49432.pdf |
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| Dessandier, Pierre-antoine; Bonnin, Jerome; Kim, Jung-hyun; Bichon, Sabrina; Deflandre, Bruno; Gremare, Antoine; Damste, Jaap S. Sinninghe. |
| Living (rose Bengal stained) benthic foraminifera were investigated on surface sediments from 23 stations from the river-dominated northwestern Portuguese margin. Samples were collected in March 2011, following the period of the maximum rainfall over the Iberian Peninsula, between 20 and 2000m water depth along five cross-margin transects. Four of them are located off the Douro, Mondego, Tagus, and Sado Rivers and one off the Estremadura coast. The major objectives of this study are (1) to assess the impact of organic matter of various origin and quality on the benthic foraminifera and (2) to investigate the spatial differences of faunal distribution from coastal waters to the deep sea under river influences. To do this, sedimentological and biogeochemical... |
| Tipo: Text |
Palavras-chave: Benthic foraminiferal ecology; Fluvial influence; Organic matter quality; Portuguese margin. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00667/77896/80083.pdf |
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| 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... |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00134/24555/23573.pdf |
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| Khalil, Karima; Raimonet, Melanie; Laverman, Anniet M.; Yan, Chen; Andrieux-loyer, Françoise; Viollier, Eric; Deflandre, Bruno; Ragueneau, Olivier; Rabouille, Christophe. |
| This paper deals with the spatial and seasonal recycling of organic matter in sediments of two temperate small estuaries (Elorn and Aulne, France). The spatio-temporal distribution of oxygen, nutrient and metal concentrations as well as the organic carbon and nitrogen contents in surficial sediments were determined and diffusive oxygen fluxes were calculated. In order to assess the source of organic carbon (OC) in the two estuaries, the isotopic composition of carbon (δ 13C) was also measured. The temporal variation of organic matter recycling was studied during four seasons in order to understand the driving forces of sediment mineralization and storage in these temperate estuaries. Low spatial variability of vertical profiles of oxygen, nutrient, and... |
| Tipo: Text |
Palavras-chave: Spatial and temporal variability; Estuarine sediment; Oxygen; Organic carbon and isotopic composition; Microelectrode; Organic matter recycling. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00164/27533/25691.pdf |
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| Lamarque, Bastien; Deflandre, Bruno; Galindo Dalto, Adriana; Schmidt, Sabine; Romero-ramirez, Alicia; Garabetian, Frédéric; Dubosq, Nicolas; Diaz, Melanie; Grasso, Florent; Sottolichio, Aldo; Bernard, Guillaume; Gillet, Hervé; Cordier, Marie-ange; Poirier, Dominique; Lebleu, Pascal; Derriennic, Hervé; Danilo, Martin; Murilo Barboza Tenório, Márcio; Grémare, Antoine. |
| The spatial distributions of (1) surface sediment characteristics (D0.5, Sediment Surface Area (SSA), Particulate Organic Carbon (POC), Chlorophyll-a (Chl-a), Phaeophytin-a (Phaeo-a), Total and Enzymatically Hydrolyzable Amino Acids (THAA, EHAA), δ13C) and (2) sediment profile image (apparent Redox Potential Discontinuity (aRPD), numbers and depths of biological traces) characteristics were quantified based on the sampling of 32 stations located within the West Gironde Mud Patch (Bay of Biscay, NE Atlantic) in view of (1) assessing the spatial structuration of a temperate river-dominated ocean margin located in a high-energy area, (2) disentangling the impacts of hydrodynamics and bottom trawling on this structuration, and (3) comparing the West Gironde... |
| Tipo: Text |
Palavras-chave: RiOMar; Surface sediment; Spatial distribution; Sedimentary organics; Bioturbation. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00681/79336/81848.pdf |
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| Fontanier, Christophe; Sakai, Saburo; Toyofuku, Takashi; Garnier, Eline; Brandily, Christophe; Eugene, Thibaut; Deflandre, Bruno. |
| Oxygen and carbon isotopes (δ18O and δ13C) have been investigated in carbonate tests of deep-sea foraminifera living in the Mozambique Channel (eastern Africa) to understand how environmental constraints (e.g., organic matter, oxygenation) control the intra- and interspecific variability of isotopic signatures. 197 living individuals, including eight different species, from various microhabitats within the sediment were sorted from sediment samples gathered at two stations on the Malagasy upper slope. Results show that the δ18O values of foraminiferal taxa were not controlled by microhabitat pattern. They presented tremendous and intriguing intraspecific variability that is not explained by the classical ontogenetic effect. The δ13C values of infaunal... |
| Tipo: Text |
Palavras-chave: Oxygen and carbon isotopes; Deep-sea foraminifera; Organic matter; Oxygenation; Microhabitat. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00357/46831/46979.pdf |
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| 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 |
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| Registros recuperados: 10 | |
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