|
|
|
Registros recuperados: 66 | |
|
| |
|
| |
|
|
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 |
| |
|
|
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 |
| |
|
|
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 |
| |
|
|
Hofker, J.. |
INTRODUCTION Of the bottom material collected by the Snellius-Expedition 78 samples contained Foraminifera. Many of these samples were extremely small, since they were gathered by means of piston core samplers; some were larger, as they were collected by means of a dredge; others were samples in shallow water at beaches or reefs. A l l samples were fixed in formaldehyde, so that after the 40 years they remained in store before they were studied, rests of protoplasma were seldom preserved. The numerous plankton samples, preserved in formaldehyde or in alcohol, did note contain planktonic Foraminifera; obviously the small amount of CaC03 in the samples caused the dissolution of the tests. The planktonic Foraminifera are not described here, as planktonic... |
Tipo: Article / Letter to the editor |
Palavras-chave: Foraminifera; Indonesia; Snellius Expedition 30; 42.94. |
Ano: 1978 |
URL: http://www.repository.naturalis.nl/record/323936 |
| |
|
|
Schmittner, Andreas; Bostock, Helen C.; Cartapanis, Olivier; Curry, William B.; Filipsson, Helena L.; Galbraith, Eric D.; Gottschalk, Julia; Carlos Herguera, Juan; Hoogakker, Babette; Jaccard, Samuel L.; Lisiecki, Lorraine E.; Lund, David C.; Martinez-mendez, Gema; Lynch-stieglitz, Jean; Mackensen, Andreas; Michel, Elisabeth; Mix, Alan C.; Oppo, Delia W.; Peterson, Carlye D.; Repschlaeger, Janne; Sikes, Elisabeth L.; Spero, Howard J.; Waelbroeck, Claire. |
The carbon isotope composition (C-13) of seawater provides valuable insight on ocean circulation, air-sea exchange, the biological pump, and the global carbon cycle and is reflected by the C-13 of foraminifera tests. Here more than 1700 C-13 observations of the benthic foraminifera genus Cibicides from late Holocene sediments (C-13(Cibnat)) are compiled and compared with newly updated estimates of the natural (preindustrial) water column C-13 of dissolved inorganic carbon (C-13(DICnat)) as part of the international Ocean Circulation and Carbon Cycling (OC3) project. Using selection criteria based on the spatial distance between samples, we find high correlation between C-13(Cibnat) and C-13(DICnat), confirming earlier work. Regression analyses indicate... |
Tipo: Text |
Palavras-chave: Carbon; Isotopes; Benthic; Foraminifera; Calibration. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00661/77326/78788.pdf |
| |
|
|
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 |
| |
|
|
Denoyelle, Marieva; Jorissen, Frans J.; Martin, Daniel; Galgani, Francois; Mine, Jacques. |
We compare foraminifera and macrofauna as bio-indicators of oil-based drill mud disposal site off Congo. The most polluted sites are characterized by poor faunas, dominated by some very tolerant taxa. Slightly further from the disposal site, there is an area with strongly increased densities, heavily dominated by opportunistic taxa. Still further, macrofauna appears to be similar to that at the reference area, but the foraminiferal meiofauna still suggests a slight environmental perturbation. The foraminiferal FIEI index, based on the species distribution in the study area, appears to be more discriminative than the macrofaunal ITI index, based on a priori definitions of the trophic guilds of the various taxa. Our comparative approach allows us to point... |
Tipo: Text |
Palavras-chave: Bio-indicators; Biotic index; Drilling mud; Foraminifera; Macrofauna. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00019/13027/10203.pdf |
| |
|
| |
|
|
Rasmussen, Tl; Oppo, Dw; Thomsen, E; Lehman, Sj. |
[1] Results from two deep sea cores from northeast of Newfoundland at 1251 and 2527 m water depth, respectively, indicate that during the time period from 160,000 to 10,000 years BP, ice rafting events in the Labrador Sea were accompanied by rapid variations in deep and surface water circulation. Twelve ice-rafting events occurred, each coinciding with high concentrations of detrital carbonate and oxygen isotopic depletion of both surface and bottom waters. Eleven of these can be correlated with the North Atlantic Heinrich events H1-H11. The remaining very conspicuous ice-rafting event took place early in MIS substage 5e, at a time when the planktic faunal assemblage suggests marked warming of the sea surface. In the shallower core, benthic delta(13)C... |
Tipo: Text |
Palavras-chave: Paleoceanography; Labrador Sea; Ice rafting; Foraminifera; Last climate cycle. |
Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00496/60768/65083.pdf |
| |
|
| |
|
|
Nouet, Julius; Bassinot, Franck. |
Several authors suggested that the thinning, with increasing depth of deposition, of calcite X-ray diffractometry (XRD) peaks obtained on planktonic foraminifera tests resulted from the preferential removal of their poorly crystallized parts as dissolution increases. By deconvolving XRD peak (104) from Globorotalia tumida (surface sediments, Sierra Leone Rise depth transect), we show that the full width at midheight does not depend only upon crystallinity, but reflects also the chemical and structural heterogeneity of foraminifera tests, which results in closely spaced, individual (104) diffraction peaks corresponding to phases with slightly different Mg contents. G. tumida contains two calcite phases: a well crystallized, Mg-poor calcite and a poorly... |
Tipo: Text |
Palavras-chave: Dissolution; Foraminifera; X-ray diffraction; Crystallinity; Deconvolution. |
Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00235/34626/32973.pdf |
| |
|
|
Hromic, Tatiana. |
Se analiza la distribución batimétrica de los foraminíferos bentónicos en el área de canales y fiordos, al sur del estrecho de Magallanes, (52-56°S), Chile. Para ello se estudiaron 34 muestras recolectadas en la zona de plataforma (35 - 650 m), durante la expedición CIMAR 3 FIORDOS (1998), organizada por el Comité Oceanográfico Nacional (CONA). Se obtuvieron 21.190 ejemplares los que fueron clasificados en 169 especies; sólo el 8,3% de las especies alcanzaron una representación superior al 2%, por lo cual, se seleccionaron 47 especies, según su abundancia por tramo, para verificar su distribución. Se reconocieron tres asociaciones: a) de aguas someras (0-150 m); en la porción más superficial (50 m) dominaron Buccella frigida, Buliminella elegantissima y... |
Tipo: Journal Contribution |
Palavras-chave: Foraminifera; Bathymetric distribution. |
Ano: 2009 |
URL: http://hdl.handle.net/1834/4176 |
| |
|
| |
|
| |
|
| |
|
|
Luzuriaga de Cruz, M.. |
La distribución del ictioplancton y zooplancton alrededor de las Islas Galápagos, 89°W, 92°30'W y 01°N, 02°S, fue realizada con datos e información proveniente de cruceros de investigación entre los años 1988 hasta 2001. Áreas de mayor abundancia de zooplancton e ictioplancton han sido identificadas hacia el norte y sur de Isla Isabela y alrededor de la Isla Fernandina, asociados a la Corriente de Cromwell y afloramiento foraminíferos planctónicos, larvas de eufásidos y copépodos fueron predominantes en las áreas mencionadas. Activa productividad secundaria relacionada con el frente ecuatorial se observó también hacia el sureste de Isabela, este de San Cristóbal y norte de Isla Santiago, con elevados porcentajes (>50%) de Globigerina bulloides... |
Tipo: Journal Contribution |
Palavras-chave: Ichthyoplankton; Zooplankton; Upwelling; Foraminifera; Abundance; Cruises; Zooplankton; Http://aims.fao.org/aos/agrovoc/c_15490. |
Ano: 2009 |
URL: http://hdl.handle.net/1834/3358 |
| |
|
| |
|
|
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 |
| |
Registros recuperados: 66 | |
|
|
|