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| Registros recuperados: 66 | |
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| Piva, A; Asioli, A; Schneider, R; Trincardi, F; Andersen, N; Colmenero Hidalgo, E; Dennielou, Bernard; Flores, J; Vigliotti, L. |
| [1] A multiproxy integrated chronological framework, based on oxygen and carbon stable isotope stratigraphy, biostratigraphy (foraminifera and nannoplankton bioevents and foraminifer assemblage-based climate cyclicity), magnetostratigraphy, sapropel stratigraphy, and C-14 AMS radiometric dates, has been achieved for borehole PRAD1-2, collected in 185.5 m water depth in the central Adriatic. This work was carried out within the European Community project Profiles across Mediterranean Sedimentary Systems (PROMESS1). The 71.2 m long borehole spans a time interval between late MIS 11 and MIS 1 (the last 370 ka), showing a chronological resolution of 500 and 250 years per cm during interglacial and glacial intervals, respectively. At present, this record is the... |
| Tipo: Text |
Palavras-chave: Sapropel stratigraphy; Adriatic Sea; D O events; Foraminifera; Oxygen isotope stratigraphy; Late Quaternary. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3605.pdf |
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| Fontanier, Christophe; Garnier, Eline; Brandily, Christophe; Dennielou, Bernard; Bichon, S.; Gayet, Nicolas; Eugene, Thibaut; Rovere, Mickael; Gremare, A.; Deflandre, B.. |
| Live (Rose-Bengal stained) deep-sea foraminiferal faunas have been studied at four stations between 530–3200-m depth in the Mozambique Channel (eastern Africa) to understand how complex environmental conditions (e.g., organic matter, oxygenation) control their ecological structure (i.e., diversity, density, and microhabitats). Two upper-slope stations, located at 530- and 780-m depth off Madagascar, are bathed by well-oxygenated bottom waters. They are characterized by fine sediments enriched in highly degraded organic matter (low amino-acid bio-availability and reduced chlorophyllic freshness). Mineralization of organic compounds results in relatively moderate oxygen penetration depth (i.e., 15 and 30 mm) in sediment. Interestingly, foraminiferal species... |
| Tipo: Text |
Palavras-chave: Mozambique Channel; Foraminifera; Diversity; Microhabitat; Organic matter. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00344/45505/45057.pdf |
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| Essallami, L.; Sicre, M. A.; Kallel, N.; Labeyrie, L.; Siani, G.. |
| Sea surface temperatures were reconstructed over the last 30,000 years from alkenone paleothermometry (SST-(alk)) and planktonic foraminifera assemblages using the Modern Analog Technique (MAT) (SST-(foram)) along two cores of the Mediterranean Sea: MD84-632 (Levantine basin) and MD04-2797 (Siculo-Tunisian Strait). Oxygen isotope of planktonic foraminifera G. bulloides for core MD04-2797 and G. ruber for core MD84-632 were also determined. SST-alk in the Levantine basin indicate colder values at the Last Glacial Maximum (LGM) (similar to 14 degrees C) than earlier established from MAT, and a cooling amplitude of 6 degrees-7 degrees C, comparable to the central Mediterranean Sea. Climatic events such as the Younger Dryas (YD) and Heinrich events 1 and 2 (H1... |
| Tipo: Text |
Palavras-chave: Paleoclimate; Glacial; Mediterranean; Alkenones; Foraminifera; Marine core. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00208/31954/30378.pdf |
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| Minto'O, Charlie Morelle Angue; Bassetti, Maria-angela; Morigi, Caterina; Ducassou, Emmanuelle; Toucanne, Samuel; Jouet, Gwenael; Mulder, Thierry. |
| Foraminifera and ostracods have been quantitatively studied in core MD01-2472, from the upper continental slope (at water depth of 501 m), to evaluate their relationship with bottom water condition variability and decipher the control of the Levantine Intermediate Water (LIW) current on benthic faunas. The occurrence of reworked ostracod species (originating from the continental shelf) and, the presence of shallow water Elphidium/Ammonia benthic foraminifera are used to estimate the degree of along-slope transport at the core site. This has revealed two intervals of along-slope transport also associated with coarse-grained contourite deposits, deposited during the YD and HS2 episodes. Planktonic-benthic foraminiferal and ostracod assemblages reflect... |
| Tipo: Text |
Palavras-chave: Ostracods; Foraminifera; LIW; Corsica margin. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00245/35648/34208.pdf |
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| Bird, Clare; Lekieffre, Charlotte; Jauffrais, Thierry; Meibom, Anders; Geslin, Emmanuelle; Filipsson, Helena L.; Maire, Olivier; Russell, Ann D.; Fehrenbacher, Jennifer S.. |
| Nitrogen availability often limits biological productivity in marine systems, where inorganic nitrogen, such as ammonium is assimilated into the food web by bacteria and photoautotrophic eukaryotes. Recently, ammonium assimilation was observed in kleptoplast-containing protists of the phylum foraminifera, possibly via the glutamine synthetase/glutamate synthase (GS/GOGAT) assimilation pathway imported with the kleptoplasts. However, it is not known if the ubiquitous and diverse heterotrophic protists have an innate ability for ammonium assimilation. Using stable isotope incubations (15N-ammonium and 13C-bicarbonate) and combining transmission electron microscopy (TEM) with quantitative nanoscale secondary ion mass spectrometry (NanoSIMS) imaging, we... |
| Tipo: Text |
Palavras-chave: Nitrogen cycle; Heterotrophic protists; Foraminifera; Ammonium assimilation; Heterotrophy; Marine. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00662/77421/79087.pdf |
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| Debenay, Jean-pierre; Tsakiridis, Erica; Soulard, René; Grossel, Hubert. |
| Port Joinville harbor is located on an island. Thus, it receives only a few freshwater inputs, contrary to most of the areas where the influence of pollution on foraminiferal assemblages has been studied. The pollution in the harbor mainly results from the boats, including cleaning, painting and outfall of oil and motor-fuel.A total of 59 sediment samples was collected at three sampling periods (November-December 1997, May 1998 and September 1998). These samplings were supplemented by the study of algal flora and macrobenthos and by the study of water circulation by means of six stations where water was collected every hour during a tide cycle. Contaminants were analyzed in the last series of 17 samples. Total assemblages were used for this study. This... |
| Tipo: Text |
Palavras-chave: France; Atlantic; Harbor; Pollution; Bioindicators; Foraminifera. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-764.pdf |
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| Carson, Brooke E.; Francis, Jason M.; Leckie, R. Mark; Droxler, Andre W.; Dickens, Gerald R.; Jorry, Stephan J.; Bentley, Sam J.; Peterson, Larry C.; Opdyke, Bradley N.. |
| Ashmore Trough in the western Gulf of Papua (GoP) represents an outstanding modern example of a tropical mixed siliciclastic-carbonate depositional system where significant masses of both river-borne silicates and bank-derived neritic carbonates accumulate. In this study, we examine how benthic foraminiferal populations within Ashmore Trough vary in response to sea level-driven paleoenvironmental changes, particularly organic matter and sediment supply. Two 11.3-m-long piston cores and a trigger core were collected from the slope of Ashmore Trough and dated using radiocarbon and oxygen isotope measurements of planktic foraminifera. Relative abundances, principal component analyses, and cluster analyses of benthic foraminiferal assemblages in sediment... |
| Tipo: Text |
Palavras-chave: Papua New Guinea; Margins; Foraminifera. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00087/19837/17482.pdf |
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| Leutert, Thomas J.; Sexton, Philip F.; Tripati, Aradhna; Piasecki, Alison; Ling Ho, Sze; Nele Meckler, A.. |
| Applying the clumped isotope (Δ47) thermometer to foraminifer microfossils offers the potential to significantly improve paleoclimate reconstructions, owing to its insensitivity to the isotopic composition of seawater (unlike traditional oxygen isotope (δ18O) analyses). However, the extent to which primary Δ47 signatures of foraminiferal calcites can be overprinted during diagenesis is not well known. Here, we present Δ47 data as well as high-resolution (∼10 kyr) δ18O and δ13C middle Eocene time series, measured on benthic and planktic foraminifera from ODP/IODP Sites 1408, 1409, 1410, 1050, 1260 and 1263 in the Atlantic Ocean. The sites examined span various oceanographic regimes, including the western tropical to mid-latitude North Atlantic, and the... |
| Tipo: Text |
Palavras-chave: Clumped isotopes; Foraminifera; Diagenesis; Eocene; Stable-isotope geochemistry; Preservation. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00495/60683/64757.pdf |
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| Le Calvez, Yolande. |
| Foraminifera were abundant in samples obtained from the Mauritanian coast. Their ecology and geographical location was studied. The genera and species are initially grouped according to the nature of the seabed and its depth. Those found in (1) deep mud at 500-1200 m, (2) muddy sand at 20-340 m, (3) shelly sand at 30-52 m are considered in turn. Group (I) varied according to the station of collection, and were affected by factors in addition to depth, such as the presence of corals. Muddy sand was poor in large individuals and in empty shells, but contained many displaced littoral forms. The very few living forms found in the shelly sand area was surprising; it may reflect the constant agitation of the sand or the small size of individuals, which could... |
| Tipo: Text |
Palavras-chave: Foraminifera; Atlantic Sahara coast; Indexing in process. |
| Ano: 1972 |
URL: http://archimer.ifremer.fr/doc/1972/publication-2045.pdf |
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| Peral, Marion; Daeron, Mathieu; Blamart, Dominique; Bassinot, Franck; Dewilde, Fabien; Smialkowski, Nicolas; Isguder, Gulay; Bonnin, Jerome; Jorissen, Frans; Kissel, Catherine; Michel, Elisabeth; Vazquez Riveiros, Natalia; Waelbroeck, Claire. |
| Accurate reconstruction of past ocean temperatures is of critical importance to paleoclimatology. Carbonate clumped isotope thermometry (“Δ47”) is a relatively recent technique based on the strong relationship between calcification temperature and the statistical excess of 13C-18O bonds in carbonates. Its application to foraminifera holds great scientific potential, particularly because Δ47 paleotemperature reconstructions do not require assumptions regarding the 18O composition of seawater. However there are still relatively few published observations investigating the potential influence of parameters such as salinity or foraminiferal size and species. We present a new calibration data set based on 234 replicate analyses of 9 planktonic and 2 benthic... |
| Tipo: Text |
Palavras-chave: Carbonate clumped isotopes; Foraminifera; Paleothermometry. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00450/56134/57676.pdf |
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| Jauffrais, Thierry; Lekieffre, Charlotte; Schweizer, Magali; Jesus, Bruno; Metzger, Edouard; Geslin, Emmanuelle. |
| The aim of this work is to document the complex nutritional strategy developed by kleptoplastic intertidal foraminifera. We study the mixotrophic ability of a common intertidal foraminifer, E. williamsoni, by (1) investigating the phylogenetic identity of the foraminiferal kleptoplasts, (2) following their oxygenic photosynthetic capacity, and (3) observing the modification in cellular ultrastructural features in response to photoautotrophic conditions. This was achieved by coupling molecular phylogenetic analyses and TEM observations with non-destructive measurements of kleptoplast O2 production over a 15-day experimental study. Results show that the studied E. williamsoni actively selected kleptoplasts mainly from pennate diatoms and had the ability to... |
| Tipo: Text |
Palavras-chave: Foraminifera; Electron microscopy; DNA barcoding; Kleptoplasty; Lipids. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00487/59894/63074.pdf |
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| Debenay, J.p.; Della Patrona, Luc; Herbland, Alain; Goguenheim, H. |
| This study was carried out in shrimp ponds from New Caledonia, in order to determine the cause of the exceptional proportion of abnormal tests (FAI) (often >50%, sometimes >80%). FAI was positively correlated to the quantity of easily oxidized material (EOM) deposited on the bottom of the ponds and to the sediment oxygen demand, and negatively correlated to redox. These results suggest that a very high FAI is a potential indicator for great accumulations of native organic matter, leading to a high sediment oxygen demand. When studying ancient sediments in core samples, exceptional abundances of abnormal tests may indicate periods of high accumulation of EOM, and therefore of oxygen depletion. This finding should help in better management of... |
| Tipo: Text |
Palavras-chave: SW Pacific; Bioindicators; Organic matter; Shrimp ponds; Deformations; Foraminifera. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6955.pdf |
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| Ingels, Jeroen; Vanreusel, Ann; Brandt, Angelika; Catarino, Ana I.; David, Bruno; De Ridder, Chantal; Dubois, Philippe; Gooday, Andrew J.; Martin, Patrick; Pasotti, Francesca; Robert, Henri. |
| Because of the unique conditions that exist around the Antarctic continent, Southern Ocean (SO) ecosystems are very susceptible to the growing impact of global climate change and other anthropogenic influences. Consequently, there is an urgent need to understand how SO marine life will cope with expected future changes in the environment. Studies of Antarctic organisms have shown that individual species and higher taxa display different degrees of sensitivity to environmental shifts, making it difficult to predict overall community or ecosystem responses. This emphasizes the need for an improved understanding of the Antarctic benthic ecosystem response to global climate change using a multitaxon approach with consideration of different levels of biological... |
| Tipo: Text |
Palavras-chave: Amphipoda; Echinoidea; Foraminifera; Global climate change; Isopoda; Nematoda; Southern Ocean; Zoobenthos. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00296/40762/39758.pdf |
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| Pascal, P.y.; Dupuy, C; Richard, P; Niquil, N. |
| The majority of sediment dweller foraminifera are deposit feeders. They use their pseudopodia to gather sediment with associated algae, organic detritus and bacteria. Uptake of bacteria by foraminifera have been observed but rarely quantified. We measured uptake of bacteria by the common foraminifera Ammonia tepida using 15N pre-enriched bacteria as tracers. In intertidal flats, seasonal, tidal and circadian cycles induce strong variations in environmental parameters. Grazing experiments were performed in order to measure effects of abiotic (temperature, salinity and irradiance) and biotic (bacterial and algal abundances) factors on uptake rates of bacteria. In mean conditions, A. tepida grazed 78 pgC ind-1 h-1 during the first eight hours of incubation,... |
| Tipo: Text |
Palavras-chave: Trophoecology; Prey abundance; Mudflat; Grazing; Foraminifera; Environmental factor; Bacteria. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4298.pdf |
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| Rustic, Gerald Thomas. |
| The El Niño Southern Oscillation (ENSO) has been implicated in large-scale climate shifts of the past millennia, but paleoclimate records from the dynamically vital eastern equatorial Pacific Ocean (EEP) spanning the past millennium are sparse. This has limited our understanding of tropical Pacific dynamics, leaving questions regarding the source of ENSO variability unanswered. Here I seek to address some of these questions regarding relationship between ENSO and tropical Pacific mean state, and the relationship between the tropical Pacific and large-scale climate. Mean EEP sea surface temperature (SST) for the past millennium was reconstructed using Mg/Ca ratios in Globigerinoides ruber from a sub-centennially resolved sediment core collected near the... |
| Tipo: Text |
Palavras-chave: Eastern tropical pacific; ENSO; Foraminifera; Paleoceanography; Paleoclimate. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00495/60657/64154.pdf |
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| Payne, Jonathan L.; Groves, John R.; Jost, Adam B.; Thienan Nguyen,; Moffitt, Sarah E.; Hill, Tessa M.; Skotheim, Jan M.. |
| Atmospheric hyperoxia, with pO2 in excess of 30%, has long been hypothesized to account for late Paleozoic (360250 million years ago) gigantism in numerous higher taxa. However, this hypothesis has not been evaluated statistically because comprehensive size data have not been compiled previously at sufficient temporal resolution to permit quantitative analysis. In this study, we test the hyperoxia-gigantism hypothesis by examining the fossil record of fusulinoidean foraminifers, a dramatic example of protistan gigantism with some individuals exceeding 10 cm in length and exceeding their relatives by six orders of magnitude in biovolume. We assembled and examined comprehensive regional and global, species-level datasets containing 270 and 1823 species,... |
| Tipo: Text |
Palavras-chave: Body size; Carboniferous; Cope's Rule; Foraminifera; Oxygen; Permian. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00265/37626/35865.pdf |
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| Weiner, Agnes K. M.; Morard, Raphael; Weinkauf, Manuel F. G.; Darling, Kate F.; André, Aurore; Quillévéré, Frédéric; Ujiie, Yurika; Douady, Christophe J.; De Vargas, Colomban; Kucera, Michal. |
| Single-cell genetic analysis is an essential method to investigate the biodiversity and evolutionary ecology of marine protists. In protist groups that do not reproduce under laboratory conditions, this approach provides the only means to directly associate molecular sequences with cell morphology. The resulting unambiguous taxonomic identification of the DNA sequences is a prerequisite for barcoding and analyses of environmental metagenomic data. Extensive single-cell genetic studies have been carried out on planktonic foraminifera over the past 20 years to elucidate their phylogeny, cryptic diversity, biogeography, and the relationship between genetic and morphological variability. In the course of these investigations, it has become evident that genetic... |
| Tipo: Text |
Palavras-chave: Foraminifera; Protists; Single-cell genetics; Cryptic diversity; Comparability; Methods; Laboratory protocols; Standardization. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00383/49460/49938.pdf |
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| Gehlen, M; Bassinot, F; Beck, L; Khodja, H. |
| Micro particle-induced X-ray emission (PIXE) is a nondestructive elemental analysis technique that can be used to map the distribution of elements with a spatial resolution of +/-4 mum(2) and a penetration depth of +/-2 mum in a calcite matrix. To test its potential to improve our understanding of trace element distribution in foraminifera shells, we mapped the Mg distribution across individual chambers of the planktonic species Globigerinoides ruber. G. ruber shells were picked from equatorial Atlantic surface sediments (Sierra Leone Rise). They ranged from well-preserved to heavily dissolved tests. The mapping of trace elements across test chambers made it possible to discriminate between variability inherent to the shell material and heterogeneity... |
| Tipo: Text |
Palavras-chave: Foraminifera; Mg/Ca; Dissolution; Trace elements; Instruments and techniques. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00228/33892/32319.pdf |
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| Registros recuperados: 66 | |
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