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1
Glock, Nicolaas, Julia Wukovits, and Alexandra-Sophie Roy. "Interactions of Globobulimina Auriculata with Nematodes: Predator Or Prey?" Journal of Foraminiferal Research 49, no. 1 (January 11, 2019): 66–75. http://dx.doi.org/10.2113/gsjfr.49.1.66.
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Abstract Studies of carnivorous behaviour of benthic foraminifers are rare and mostly focused on laboratory experiments. Controlled experiments have shown that some agglutinated and intertidal species prey on meio- to macrofaunal metazoans. Here we present observations of the behaviour of specimens of the infaunal benthic foraminiferal species, Globobulimina auriculata and G. turgida, made within several hours of collection from ∼117 m depth in the Alsbäck Deep of the Gullmar Fjord, Sweden. We observed live nematodes within the tests of G. auriculata. Video observations recorded over a 17-hour period showed a G. auriculata specimen with a living nematode whose tail appeared to be entangled within the foraminifer's reticulopodial network. The nematode eventually coiled around the foraminifer's aperture and became much less active, though ingestion into the foraminifer's test was not documented. If these observations indicate feeding by G. auriculata, they differ from previous observations of predation by Ammonia tepida, which utilised external reticulopodial activity to extract the soft tissue of its prey. An alternative interpretation of the video observations, consistent with the observations of the live nematodes inside G. auriculata, was that the nematode was attempting to prey upon the foraminifer. The G. turgida specimens, in contrast, relatively quickly surrounded themselves in soft sediment spheres commonly seen in deposit-feeding foraminifers, and were never observed with nematodes within their tests. We speculate that these contrasting feeding strategies might reduce competition and facilitate the coexistence of these two globobuliminid species.
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Roy, T., F. Lombard, L. Bopp, and M. Gehlen. "Projected impacts of climate change and ocean acidification on the global biogeography of planktonic Foraminifera." Biogeosciences 12, no. 10 (May 19, 2015): 2873–89. http://dx.doi.org/10.5194/bg-12-2873-2015.
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Abstract. Planktonic Foraminifera are a major contributor to the deep carbonate flux and their microfossil deposits form one of the richest databases for reconstructing paleoenvironments, particularly through changes in their taxonomic and shell composition. Using an empirically based planktonic foraminifer model that incorporates three known major physiological drivers of their biogeography – temperature, food and light – we investigate (i) the global redistribution of planktonic Foraminifera under anthropogenic climate change and (ii) the alteration of the carbonate chemistry of foraminiferal habitat with ocean acidification. The present-day and future (2090–2100) 3-D distributions of Foraminifera are simulated using temperature, plankton biomass and light from an Earth system model forced with a historical and a future (IPCC A2) high CO2 emission scenario. Foraminiferal abundance and diversity are projected to decrease in the tropics and subpolar regions and increase in the subtropics and around the poles. Temperature is the dominant control on the future change in the biogeography of Foraminifera. Yet food availability acts to either reinforce or counteract the temperature-driven changes. In the tropics and subtropics the largely temperature-driven shift to depth is enhanced by the increased concentration of phytoplankton at depth. In the higher latitudes the food-driven response partly offsets the temperature-driven reduction both in the subsurface and across large geographical regions. The large-scale rearrangements in foraminiferal abundance and the reduction in the carbonate ion concentrations in the habitat range of planktonic foraminifers – from 10–30 μmol kg−1 in their polar and subpolar habitats to 30–70 μmol kg−1 in their subtropical and tropical habitats – would be expected to lead to changes in the marine carbonate flux. High-latitude species are most vulnerable to anthropogenic change: their abundance and available habitat decrease and up to 10% of the volume of their habitat drops below the calcite saturation horizon.
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Senowbari-Daryan, Baba, and Michael Link. "Foraminifera from the Norian–Rhaetian reef carbonates of the Taurus Mountains (Saklıkent, Turkey)." Geologica Carpathica 68, no. 4 (August 1, 2017): 303–17. http://dx.doi.org/10.1515/geoca-2017-0021.
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AbstractNorian–Rhaetian reef carbonates are exposed in several localities in Taurus Mountains. They predominately contain hypercalcified sponges, followed by scleractinian corals and other less numerous organisms. A coherent Norian–Rhaetian reef structure is exposed near the small town of Saklıkent, west of Antalya. Foraminifers occur in reef carbonates of Saklıkent by numerous genera as shown in this paper. Two species —Siculocosta tauricaandSiculocosta sadati— are described as new. The foraminiferal association of Saklıkent is similar or almost identical to the associations known from the Norian–Rhaetian reefs of Sicily, Northern Calcareous Alps, and Greece but shows less similarity to the foraminiferal association from the Apennines, Italy. The most abundant foraminifers are milioliporoids, particularly galeanellids and cucurbitids. Some sessile and agglutinated foraminifers, includingAlpinophragmium perforatumFlügel, which mostly occurs abundantly in the Norian–Rhaetian reef carbonates, could not be found in the Saklıkent reef. This association of foraminifera is reported for the first time from a Norian–Rhaetian reef in the Taurus Mountains of Turkey.
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Glock, Nicolaas, Alexandra-Sophie Roy, Dennis Romero, Tanita Wein, Julia Weissenbach, Niels Peter Revsbech, Signe Høgslund, David Clemens, Stefan Sommer, and Tal Dagan. "Metabolic preference of nitrate over oxygen as an electron acceptor in foraminifera from the Peruvian oxygen minimum zone." Proceedings of the National Academy of Sciences 116, no. 8 (February 6, 2019): 2860–65. http://dx.doi.org/10.1073/pnas.1813887116.
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Benthic foraminifera populate a diverse range of marine habitats. Their ability to use alternative electron acceptors—nitrate (NO3−) or oxygen (O2)—makes them important mediators of benthic nitrogen cycling. Nevertheless, the metabolic scaling of the two alternative respiration pathways and the environmental determinants of foraminiferal denitrification rates are yet unknown. We measured denitrification and O2respiration rates for 10 benthic foraminifer species sampled in the Peruvian oxygen minimum zone (OMZ). Denitrification and O2respiration rates significantly scale sublinearly with the cell volume. The scaling is lower for O2respiration than for denitrification, indicating that NO3−metabolism during denitrification is more efficient than O2metabolism during aerobic respiration in foraminifera from the Peruvian OMZ. The negative correlation of the O2respiration rate with the surface/volume ratio is steeper than for the denitrification rate. This is likely explained by the presence of an intracellular NO3−storage in denitrifying foraminifera. Furthermore, we observe an increasing mean cell volume of the Peruvian foraminifera, under higher NO3−availability. This suggests that the cell size of denitrifying foraminifera is not limited by O2but rather by NO3−availability. Based on our findings, we develop a mathematical formulation of foraminiferal cell volume as a predictor of respiration and denitrification rates, which can further constrain foraminiferal biogeochemical cycling in biogeochemical models. Our findings show that NO3−is the preferred electron acceptor in foraminifera from the OMZ, where the foraminiferal contribution to denitrification is governed by the ratio between NO3−and O2.
5
Martinez, Ana, Laura Hernández-Terrones, Mario Rebolledo-Vieyra, and Adina Paytan. "Impact of carbonate saturation on large Caribbean benthic foraminifera assemblages." Biogeosciences 15, no. 22 (November 16, 2018): 6819–32. http://dx.doi.org/10.5194/bg-15-6819-2018.
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Abstract. Increasing atmospheric carbon dioxide and its dissolution in seawater have reduced ocean pH and carbonate ion concentrations, with potential implications on calcifying organisms. To assess the response of large Caribbean benthic foraminifera to low carbonate saturation conditions, we analyzed benthic foraminifers' abundance and relative distribution in surface sediments in proximity to low-carbonate-saturation submarine springs and at adjacent control sites. Our results show that the total abundance of large benthic foraminifera was significantly lower at the low-pH submarine springs than at control sites, although responses were species specific. The relative abundance of high-magnesium, porcelaneous foraminifera was higher than that of hyaline foraminifera at the low-pH springs due to the abundant Archaias angulatus, a chlorophyte-bearing foraminifer, which secretes a large and robust test that is more resilient to dissolution at low-calcite saturation. The different assemblages found at the submarine springs indicate that calcareous symbiont-barren foraminifera are more sensitive to the effects of ocean acidification than agglutinated and symbiont-bearing foraminifera, suggesting that future ocean acidification will likely impact natural benthic foraminifera populations.
6
Roy, T., F. Lombard, L. Bopp, and M. Gehlen. "Projected impacts of climate change and ocean acidification on the global biogeography of planktonic foraminifera." Biogeosciences Discussions 11, no. 6 (June 30, 2014): 10083–121. http://dx.doi.org/10.5194/bgd-11-10083-2014.
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Abstract. Planktonic foraminifera are a major contributor to the deep carbonate-flux and the planktonic biomass of the global ocean. Their microfossil deposits form one of the richest databases for reconstructing paleoenvironments, particularly through changes in their taxonomic and shell composition. Using an empirically-based foraminifer model that incorporates three known major physiological drivers of foraminifer biogeography – temperature, food and light – we investigate (i) the global redistribution of planktonic foraminifera under anthropogenic climate change, and (ii) the alteration of the carbonate chemistry of foraminifer habitat with ocean acidification. The present-day and future (2090–2100) 3-D distributions of foraminifera are simulated using temperature, plankton biomass, and light from an Earth system model forced with historical and a future (IPCC A2) high CO2 emission scenario. The broadscale patterns of present day foraminifer biogeography are well reproduced. Foraminifer abundance and diversity are projected to decrease in the tropics and subpolar regions and increase in the subtropics and around the poles. In the tropics, the geographical shifts are driven by temperature, while the vertical shifts are driven by both temperature and food availability. In the high-latitudes, vertical shifts are driven by food availability, while geographical shifts are driven by both food availability and temperature. Changes in the marine carbon cycle would be expected in response to (i) the large-scale rearrangements in foraminifer abundance, and (ii) the reduction of the carbonate concentration in the habitat range of planktonic foraminifers: from 10–30 μmol kg−1 in the polar/subpolar regions to 30–70 μmol kg−1 in the subtropical/tropical regions. High-latitude species are most vulnerable to anthropogenic change: their abundance and available habitat decrease and up to 10% of their habitat drops below the calcite saturation horizon.
7
Pearson, Paul N. "Oxygen Isotopes in Foraminifera: Overview and Historical Review." Paleontological Society Papers 18 (November 2012): 1–38. http://dx.doi.org/10.1017/s1089332600002539.
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Foraminiferal tests are a common component of many marine sediments. The oxygen isotope ratio (δ18O) of test calcite is frequently used to reconstruct aspects of their life environment. The δ18O depends mainly on the isotope ratio of the water it is precipitated from, the temperature of calcification, and, to a lesser extent, the carbonate ion concentration. Foraminifera and other organisms can potentially preserve their original isotope ratio for many millions of years, although diagenetic processes can alter the ratios. Work on oxygen isotope ratios of foraminifera was instrumental in the discovery of the orbital theory of the ice ages and continues to be widely used in the study of rapid climate change. Compilations of deep sea benthic foraminifer oxygen isotopes have revealed the long history of global climate change over the past 100 million years. Planktonic foraminifer oxygen isotopes are used to investigate the history of past sea surface temperatures, revealing the extent of past ‘greenhouse’ warming and global sea surface temperatures.
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Keul, N., G. Langer, L. J. de Nooijer, and J. Bijma. "Effect of ocean acidification on the benthic foraminifera <i>Ammonia</i> sp. is caused by a decrease in carbonate ion concentration." Biogeosciences 10, no. 10 (October 1, 2013): 6185–98. http://dx.doi.org/10.5194/bg-10-6185-2013.
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Abstract. About 30% of the anthropogenically released CO2 is taken up by the oceans; such uptake causes surface ocean pH to decrease and is commonly referred to as ocean acidification (OA). Foraminifera are one of the most abundant groups of marine calcifiers, estimated to precipitate ca. 50 % of biogenic calcium carbonate in the open oceans. We have compiled the state of the art literature on OA effects on foraminifera, because the majority of OA research on this group was published within the last three years. Disparate responses of this important group of marine calcifiers to OA were reported, highlighting the importance of a process-based understanding of OA effects on foraminifera. We cultured the benthic foraminifer Ammonia sp. under a range of carbonate chemistry manipulation treatments to identify the parameter of the carbonate system causing the observed effects. This parameter identification is the first step towards a process-based understanding. We argue that [CO32−] is the parameter affecting foraminiferal size-normalized weights (SNWs) and growth rates. Based on the presented data, we can confirm the strong potential of Ammonia sp. foraminiferal SNW as a [CO32−] proxy.
9
Natsir, Suhartati M. "THE DISTRIBUTION OF BENTHIC FORAMINIFERA IN DAMAR ISLAND AND JUKUNG ISLAND, SERIBU ISLANDS." Marine Research in Indonesia 35, no. 2 (December 31, 2010): 9. http://dx.doi.org/10.14203/mri.v35i1.10.
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Seribu Islands are archipelago within Jakarta Bay built upon the pleistocene coral formation of the Sunda Shelf. The islands are characterized by unique and high biodiversity such as coral reefs. Since coral reef degradation would lead to a decrease of human prosperity, the determination of the coral reef quality is of high importance. Foraminifera offers an early warning system for the coral reef condition, as exemplified by the FORAM Index, i.e. Foraminifera in Reef Assessment and Monitoring Index. This study compared the foraminiferal community structure and the FORAM Index of two islands between the Damar Besar and Jukung. Both islands were dominated by symbiont-bearing foraminifera of the genera Amphistegina, Calcarina, Heterostegina, Marginophora, and Operculina. However, the number of benthic foraminifers at Jukung Island was higher than that at Damar Besar Island, having 17 individuals per species on average. Jukung Island was a conducive site to reef growth, as indicated by a FORAM Index (between 6,48 and 6,57), and Damar Besar Island was liable to environmental change.
10
Natsir, Suhartati M. "THE DISTRIBUTION OF BENTHIC FORAMINIFERA IN DAMAR ISLAND AND JUKUNG ISLAND, SERIBU ISLANDS." Marine Research in Indonesia 35, no. 2 (December 31, 2010): 9–14. http://dx.doi.org/10.14203/mri.v35i2.10.
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Seribu Islands are archipelago within Jakarta Bay built upon the pleistocene coral formation of the Sunda Shelf. The islands are characterized by unique and high biodiversity such as coral reefs. Since coral reef degradation would lead to a decrease of human prosperity, the determination of the coral reef quality is of high importance. Foraminifera offers an early warning system for the coral reef condition, as exemplified by the FORAM Index, i.e. Foraminifera in Reef Assessment and Monitoring Index. This study compared the foraminiferal community structure and the FORAM Index of two islands between the Damar Besar and Jukung. Both islands were dominated by symbiont-bearing foraminifera of the genera Amphistegina, Calcarina, Heterostegina, Marginophora, and Operculina. However, the number of benthic foraminifers at Jukung Island was higher than that at Damar Besar Island, having 17 individuals per species on average. Jukung Island was a conducive site to reef growth, as indicated by a FORAM Index (between 6,48 and 6,57), and Damar Besar Island was liable to environmental change.
11
Ivanova, Daria K., Ján Schlögl, Adam Tomašových, Bernard Lathuilière, and Marián Golej. "Revisiting the Age of Jurassic Coral Bioherms in the Pieniny Klippen Belt (Western Carpathians) on the Basis of Benthic Foraminifers." Geologica Carpathica 70, no. 2 (April 1, 2019): 113–34. http://dx.doi.org/10.2478/geoca-2019-0007.
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Abstract Coral bioherms of the Vršatec Limestone that formed massive, several tens of meters thick complexes during the Jurassic were important sources of carbonate production, with carbonate sediment exported to deeper parts of the Pieniny Klippen Basin (Western Carpathians). However, the age of these carbonate factories remains controversial. New analyses of benthic foraminiferal assemblages occurring in coral bioherms and peri-biohermal deposits of the Vršatec Limestone at five sites in the western Pieniny Klippen Belt (Vršatec-Castle, Vršatec-Javorníky, Malé Hradište, Malé Hradište-Kalvária, and Drieňová Hora) show that these sediments were deposited during the Bajocian and were lateral equivalents of crinoidal limestones and breccias, in contrast to previous studies suggesting that they were deposited during the Oxfordian. First, all sites are characterized by similar composition of foraminiferal assemblages on the basis of presence–absence data, although foraminiferal assemblages in biosparitic facies at Vršatec are dominated by miliolids whereas biomicritic facies at Malé Hradište are dominated by the spirillinid Paalzowella. The composition of foraminiferal assemblages does not differ between the lower and upper parts of the Vršatec Limestone. Second, foraminifer species that were assumed to appear for the first time in the Oxfordian already occur in the Middle Jurassic sediments of the northern Tethyan shelf. Third, the first and last appearances of foraminifers documented in other Tethyan regions are in accordance with stratigraphic analyses and ammonoid occurrences, demonstrating that bioherm-forming coral communities developed on the Czorzstyn Ridge during the Bajocian. Several species of foraminifers of the Vršatec Limestone appeared for the first time during the middle or late Aalenian (Labalina occulta, Paalzowella feifeli) and during the Bajocian (Hungarillina lokutiense, Radiospirillina umbonata, Ophthalmidium caucasicum, O. terquemi, O. obscurum, Paalzowella turbinella, Cornuspira tubicomprimata, Nubecularia reicheli) or appeared for the last time in the Bajocian (Tethysiella pilleri) or Early Bathonian (Ophthalmidium caucasicum, O. obscurum). The composition and diversity of communities with benthic foraminifers of the Vršatec Limestone is similar to the composition of foraminiferal communities on carbonate platform environments with corals of the French Jura and Burgundy during the Bajocian.
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Ayala-López, Adriana, and Adolfo Molina-Cruz. "Micropalaeontology of the hydrothermal region in the Guaymas Basin, Mexico." Journal of Micropalaeontology 13, no. 2 (December 1, 1994): 133–46. http://dx.doi.org/10.1144/jm.13.2.133.
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Abstract. A micropalaeontological analysis of 40 sedimentary samples from a hydrothermal region in the Guaymas Basin, Gulf of California, Mexico, was carried out to describe microenvironments. These microenvironments were defined through a Q-mode Factor analysis of species abundance data from the benthic foraminiferal biocoenoses and thanatocoenoses. The benthic foraminiferal results were correlated with the biogeographic patterns of diatoms, radiolarians, planktonic foraminifers and ostracods through a ‘graphic-multivariate analysis’. Although the microenvironments have a patchy distribution within the hydrothermal region, it is possible to define the following: (1) the ‘hydrothermal environment’, in which the benthic foraminifera Bulimina mexicana and Globocassidulina sp. cf. C. subglobosa coexist with the mollusc Calyptogena pacifica, even though the almost direct influence of the hydrothermal fluids drastically reduces the presence of the microfauna; (2) the ‘bacterial environment’, in which Trochammina sp. and Recurvoides sp. are associated with bacterial mats; and (3) the ‘cool environment’, further out from the direct hydrothermal influence. In this microenvironment the benthic foraminifera Bulimina spinosa, Bolivina seminuda and Cibicides sp. are common. These three benthic foraminiferal assemblages are different from other assemblages which live in the Guaymas Basin but are not influenced by hydrothermal fluids. In the non-hydrothermal regions, Uvigerina peregrina and Buliminella tenuata are common. The analysis of subsurface samples shows the same patterns as the superficial samples.
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Bhattacharjee, Dola, B. C. Choudhury, K. Sivakumar, Charu Sharma, Sajan John, Satyaranjan Behera, Subrata Behera, and Punyasloke Bhadury. "Benthic foraminifera assemblages in turtle congregation sites along the north-east coast of India." Journal of the Marine Biological Association of the United Kingdom 93, no. 4 (October 24, 2012): 877–87. http://dx.doi.org/10.1017/s0025315412001440.
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Near-shore recent benthic foraminifera from three ecologically important (Olive Ridley turtle congregation sites) but vulnerable sites encompassing 23 sampling stations (12 in Rushikulya, 5 in Devi and 6 in Gahirmatha) along coastal Orissa, north-west Bay of Bengal (BoB) in India were studied for the first time for their composition, distribution and assemblage patterns. Thirty-nine species of benthic foraminifers (from 6 orders and 23 families) were identified of which all 39 were present in Rushikulya, 22 in Devi and 12 in Gahirmatha with abundance ranging from 35–2620 individuals/10 cm3 in the sediments. The communities across the sites were dominated by eurytopic rotalids followed by miliolids and textularids. Benthic foraminifer assemblages were found to be dominated by Ammonia species complex (up to 38% in Rushikulya, 64% in Devi and 22% in Gahirmatha). Agglutinated foraminifers were infrequent in the sediments (7 species in Rushikulya, 4 species in Devi and 3 in Gahirmatha) on the other hand, being dominated by Quinqueloculina agglutinans in Rushikulya and Trochammina macrescens and Ammobaculites agglutinans in Devi and Gahirmatha. The substrates along the study sites were found mostly to be sand dominated and in some of the stations sediment composition influenced the foraminifer distribution pattern. The present findings on the assemblage patterns of benthic foraminifers from three coastal settings in Orissa along the BoB are comparable with previous reports from other sandy coastal ecosystems in the world. Overall these data provide valuable insights into the distribution and assemblage patterns of benthic foraminifers from the BoB coastal regions.
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Keul, N., G. Langer, L. J. de Nooijer, and J. Bijma. "Effect of ocean acidification on the benthic foraminifera <i>Ammonia</i> sp. is caused by a decrease in carbonate ion concentration." Biogeosciences Discussions 10, no. 1 (January 25, 2013): 1147–76. http://dx.doi.org/10.5194/bgd-10-1147-2013.
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Abstract. About 30% of the anthropogenically released CO2 is taken up by the oceans, which causes surface ocean pH to decrease and is commonly referred to as Ocean Acidification (OA). Foraminifera are one of the most abundant groups of marine calcifiers, estimated to precipitate ca. 50% of biogenic calcium carbonate in the open oceans. We have compiled the state of the art of OA effects on foraminifera, because the majority of OA research on this group was published within the last 3 yr. Disparate responses of this important group of marine calcifiers to OA were reported, highlighting the importance of a process based understanding of OA effects on foraminifera. The benthic foraminifer Ammonia sp. was cultured using two carbonate chemistry manipulation approaches: While pH and carbonate ions where varied in one, pH was kept constant in the other while carbonate ion concentration varied. This allows the identification of teh parameter of the parameter of the carbonate system causing observed effects. This parameter identification is the first step towards a process based understanding. We argue that [CO32−] is the parameter affecting foraminiferal size normalized weights (SNW) and growth rates and based on the presented data we can confirm the strong potential of foraminiferal SNW as a [CO32−] proxy.
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LeKieffre, Charlotte, Howard J. Spero, Jennifer S. Fehrenbacher, Ann D. Russell, Haojia Ren, Emmanuelle Geslin, and Anders Meibom. "Ammonium is the preferred source of nitrogen for planktonic foraminifer and their dinoflagellate symbionts." Proceedings of the Royal Society B: Biological Sciences 287, no. 1929 (June 17, 2020): 20200620. http://dx.doi.org/10.1098/rspb.2020.0620.
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The symbiotic planktonic foraminifera Orbulina universa inhabits open ocean oligotrophic ecosystems where dissolved nutrients are scarce and often limit biological productivity. It has previously been proposed that O. universa meets its nitrogen (N) requirements by preying on zooplankton, and that its symbiotic dinoflagellates recycle metabolic ‘waste ammonium’ for their N pool. However, these conclusions were derived from bulk 15 N-enrichment experiments and model calculations, and our understanding of N assimilation and exchange between the foraminifer host cell and its symbiotic dinoflagellates remains poorly constrained. Here, we present data from pulse-chase experiments with 13 C-enriched inorganic carbon, 15 N-nitrate, and 15 N-ammonium, as well as a 13 C- and 15 N- enriched heterotrophic food source, followed by TEM (transmission electron microscopy) coupled to NanoSIMS (nanoscale secondary ion mass spectrometry) isotopic imaging to visualize and quantify C and N assimilation and translocation in the symbiotic system. High levels of 15 N-labelling were observed in the dinoflagellates and in foraminiferal organelles and cytoplasm after incubation with 15 N-ammonium, indicating efficient ammonium assimilation. Only weak 15 N-assimilation was observed after incubation with 15 N-nitrate. Feeding foraminifers with 13 C- and 15 N-labelled food resulted in dinoflagellates that were labelled with 15 N, thereby confirming the transfer of 15 N-compounds from the digestive vacuoles of the foraminifer to the symbiotic dinoflagellates, likely through recycling of ammonium. These observations are important for N isotope-based palaeoceanographic reconstructions, as they show that δ 15 N values recorded in the organic matrix in symbiotic species likely reflect ammonium recycling rather than alternative N sources, such as nitrates.
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Burki, Fabien, Sergey I. Nikolaev, Ignacio Bolivar, Jackie Guiard, and Jan Pawlowski. "Analysis of expressed sequence tags from a naked foraminiferan Reticulomyxa filosa." Genome 49, no. 8 (August 1, 2006): 882–87. http://dx.doi.org/10.1139/g06-048.
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Foraminifers are a major component of modern marine ecosystems and one of the most important oceanic producers of calcium carbonate. They are a key phylogenetic group among amoeboid protists, but our knowledge of their genome is still mostly limited to a few conserved genes. Here, we report the first study of expressed genes by means of expressed sequence tag (EST) from the freshwater naked foraminiferan Reticulomyxa filosa. Cluster analysis of 1630 valid ESTs enabled the identification of 178 groups of related sequences and 871 singlets. Approximately 50% of the putative unique 1059 ESTs could be annotated using Blast searches against the protein database SwissProt + TrEMBL. The EST database described here is the first step towards gene discovery in Foraminifera and should provide the basis for new insights into the genomic and transcriptomic characteristics of these interesting but poorly understood protists.Key words: Rhizaria, Foraminifera, cDNA library, annotation.
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Gasiński, M. Adam, Alexandra Olshtynska, and Alfred Uchman. "Late Maastrichtian foraminiferids and diatoms from the Polish Carpathians (Ropianka Formation, Skole Nappe): a case study from the Chmielnik-Grabówka composite section." Acta Geologica Polonica 63, no. 4 (December 1, 2013): 515–25. http://dx.doi.org/10.2478/agp-2013-0022.
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ABSTRACT Gasiński, M.A., Olshtynska, A. and Uchman, A. 2013. Late Maastrichtian foraminiferids and diatoms from the Polish Carpathians (Ropianka Formation, Skole Nappe): a case study from the Chmielnik-Grabowka composite section. Acta Geologica Polonica, 63(4), 515-525. Warszawa. Well-preserved foraminiferids have been found in the Chmielnik-Grabowka section (Skole Nappe, Polish Carpathians). The Abathomphalus mayaroensis (late Maastrichtian) and Racemiguembelina fructicosa (earlylate Maastrichtian) standard planktonic foraminiferal biozones have been recognized, based on the occurrence of their respective index species. Sediments of the R. fructicosa Zone contain diatoms, which are a rare component of Cretaceous flysch microfossil assemblages in the Carpathians. The diatom frustules and some foraminiferid tests are pyritized, probably after burial in the sediment, below the redox boundary or in the oxygen- deficient microenvironment inside the frustules or tests of microfossils; the presence of trace fossils and bioturbational structures in the same bed indicate an oxygenated sea floor.
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Zehnich, Marc, Robert F. Spielhagen, Henning A. Bauch, Matthias Forwick, H. Christian Hass, Tina Palme, Ruediger Stein, and Nicole Syring. "Environmental variability off NE Greenland (western Fram Strait) during the past 10,600 years." Holocene 30, no. 12 (August 13, 2020): 1752–66. http://dx.doi.org/10.1177/0959683620950393.
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To reconstruct the climatic and paleoceanographic variability offshore Northeast Greenland during the last ~10 ka with multidecadal resolution, sediment core PS93/025 from the outermost North-East Greenland continental shelf (80.5°N) was studied by a variety of micropaleontological, sedimentological and isotopic methods. High foraminiferal fluxes, together with high proportions of ice-rafted debris and high Ca/Fe ratios, indicate a maximum in bioproductivity until ~8 ka related to a low sea-ice coverage. Sortable silt values, planktic foraminifer associations, and stable isotope data of planktic and benthic foraminifers suggest a strong westward advection of relatively warm Atlantic Water by the Return Atlantic Current during this time, with a noticeable bottom current activity. This advection may have been facilitated by a greater water depth at our site, resulting from postglacial isostatic depression. For the following mid-Holocene interval (ca. 8–5 ka), isotope data, lower foraminiferal fluxes and a shift in grain size maxima point to a lasting but successively decreasing Atlantic Water inflow, a weakening productivity, and a growing sea-ice coverage which is also revealed by the PIIIIP25 index. A final stage in the environmental development was reached at ~5 ka with the establishment of pre-industrial conditions. Low Ca/Fe ratios, low foraminiferal fluxes, low sortable silt values and the sea-ice indicating PIIIIP25 index point to a limited productivity and a weak Atlantic Water inflow by the Return Atlantic Current to our research area, as well as a higher and/or seasonally more extended sea-ice coverage during the Late Holocene. Two intervals with somewhat enhanced Atlantic Water advection around 2.0 and 1.0 ka are indicated by slightly increased foraminiferal fluxes and the reoccurrence of subpolar foraminifers. These intervals may correlate with the Roman Warm Period and the Medieval Climate Anomaly, as defined in the North Atlantic region.
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Gooday, Andrew J. "Some recent advances in the study of deep-sea foraminiferal biology and their palaeoecological significance." Paleontological Society Special Publications 6 (1992): 111. http://dx.doi.org/10.1017/s2475262200006717.
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During the past two decades, biologists have become increasingly aware of the diversity and abundance of foraminifera in marine benthic ecosystems. These protists are probably the most important eukaryotes present in ocean floor communities. In some areas, particularly central oceanic regions, foraminiferal assemblages are dominated by newly discovered, soft-bodied forms with morphologies quite unlike those of “conventional” foraminifers and with little fossilisation potential. However, despite the presumed loss of these delicate forms from the fossil record, foraminiferal tests are still the only microfossils to occur commonly in ancient deep-sea sediments. Thus, they are a focus of attention for both geologists and biologists. This presentation will concentrate on two main areas of biological research which have palaeontological significance.Foraminiferal microhabitats. Recent research indicates that particular species tend to live infaunally (deep or shallow), epifaunally or suprabenthically. Growth above or below the sediment-water interface has major implications for the stable isotope chemistry of calcareous tests, an important tool in palaeooceanography. Other species inhabit organic detritus composed of phytoplankton material rapidly sedimented from the euphotic zone. This “phytodetritus” arrives suddenly on the ocean floor following the spring bloom and is quickly colonized by foraminiferal species which feed on it, reproduce and rapidly develop large populations. These populations collapse when the food source is exhausted. The direct consumption of phytodetritus (and other organic matter inputs) by benthic foraminifers may be a widespread phenomenon which influences their population dynamics, regional distribution patterns and isotope chemistry.Recolonization. The defaunation of large tracts of ocean floor by turbidity currents or anoxic events must have happened on countless occasions over geological time, particularly along ocean margins and in basinal areas. Evidence from sediment tray experiments suggests that it may take several years for a stable community (including foraminifers) to become reestablished in small areas of defaunated sediment. Large devastated areas may require substantially longer to recover. However, on the Madeira Abyssal Plain, a normal foraminiferal assemblage occurs on the surface of a turbidite deposited several hundred years ago, suggesting that large-scale recolonization may occupy decades rather than centuries. The fossil foraminiferal assemblages present in deep-water flysch sequences are presumably the product of similar recolonization (?successional) events.These and other biological processes often operate on time scales (days, months, years) which usually can not be resolved in the stratigraphic record. This inevitably complicates the application of biological research to palaeontology.
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Reolid, Matías, Jesús Reolid, Dorothea Bunzel, Michael A. Kaminski, and Christian Betzler. "Recent Arborescent Dendrophryid Foraminifera Found On Upper Pleistocene Cold-water Corals from the Inner Sea of the Maldives." Journal of Foraminiferal Research 48, no. 1 (January 1, 2018): 53–61. http://dx.doi.org/10.2113/gsjfr.48.1.53.
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Abstract Recent specimens of Spiculidendron were found on Late Pleistocene (21,400–22,500 BP) cold-water corals from the sea floor at 457 m depth of the inter-atoll Kardiva Channel of the eastern row of the Maldives archipelago. Spiculidendron and other dendrophryid foraminifera (Rhizammina-like forms) exclusively colonized specimens of the genus Enallopsammia, which was characterized by a phosphatic-stain surface. The Spiculidendron wall was composed of sponge spicules, elongated diatom frustules, tests of juvenile benthic and planktic foraminifera, and calcareous nannoplankton, among other materials. Sponge spicules and elongated diatom frustules were arranged longitudinally, with foraminiferal tests and other bioclasts packed in between, indicating that the agglutination process of Spiculidendron is selective with respect to the manner of growth. In the most distal parts of the branches, only sponge spicules and elongated diatom frustules were present, working as guides for the test construction, prior to the agglutination of juvenile foraminiferal tests and other bioclasts. Moreover, in the sediment associated with the coral fragments, 94 species of benthic foraminifera were identified, an assemblage distinct from the taxa incorporated into the agglutinated Spiculidendron tests. The process of wall growth is complex and ordered. This foraminifer, as well as the Rhizammina-like specimens, tolerates dysoxic conditions (0.896 ml/l) and low temperature (12°C). This observation represents a new record of Spiculidendron from the Indian Ocean and from deeper (aphotic) environments than previously reported from the shallow waters of the Caribbean. A cryptobiontic habitat is interpreted for Spiculidendron.
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de Nooijer, L. J., G. Langer, G. Nehrke, and J. Bijma. "Physiological controls on seawater uptake and calcification in the benthic foraminifer <i>Ammonia tepida</i>." Biogeosciences 6, no. 11 (November 27, 2009): 2669–75. http://dx.doi.org/10.5194/bg-6-2669-2009.
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Abstract. To analyze the relation between seawater uptake and calcification, we incubated juveniles of the benthic foraminifer Ammonia tepida with various fluorescent probes and visualised them afterwards with confocal laser scanning microscopy. Vesicle membranes, Ca ions and vacuole fluids were followed with various tracers and showed for the first time that endocytosis of seawater is part of the calcification process in Ammonia tepida. Data on the intracellular Ca ion cycling allowed for calculating a preliminary cellular Ca budget during foraminiferal calcification. This showed that the free calcium involved in the production of a new chamber cannot be sufficient and suggests that foraminifera may precipitate their calcite from an amorphous precursor.
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Ozdínová, Silvia, and Ján Soták. "Oligocene-Early Miocene Planktonic Microbiostratigraphy and Paleoenvironments of the South Slovakian Basin (Lučenec Depression)." Geologica Carpathica 65, no. 5 (January 31, 2015): 451–70. http://dx.doi.org/10.1515/geoca-2015-0005.
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Abstract Oligocene and Lower Miocene sediments of the Lučenec Depression were studied to demonstrate the planktonic bioevents and climatic proxies from the Číž Formation (Rupelian) and Lučenec Formation (Chattian-Aquitanian) on the basis of quantitative analyses of foraminifers and calcareous nannofossils. The oldest nannofossil assemblages of the Číž Formation belonged to the NP23 Zone and were dominated by Reticulofenestra ornata known for preference of temperate eutrophic water conditions. An increase in bioproductivity was documented by abundant large-sized planktonic foraminifers (e.g. Turborotalia ampliapertura, Paragloborotalia nana, Subbotina gortanii) and epifaunal to shal-low-infaunal benthic species. The middle part of the Číž Formation reveals a lowstand progradation of deltaic sediments of the Rapovce Member. There, the planktonic foraminifers are impoverished in both size and diversity, containing mostly tenuitellid and cassigerinellid species, probably as a result of decreased salinity and increased anoxia in the Tard Clay. Contrary of this, the benthic foraminifers are rich, mainly the infaunal forms of uvigerinid species. They probably proliferated due to a high organic flux from riverine input. Open marine conditions were restored in the upper part of the Číž Formation above the lowest occurrence (LO) of Cyclicargolithus abisectus on the NP23-NP24 zone boundary. The transitional interval between the Číž and Lučenec formations (O5/O6 - NP24/25) was approximated by the HOs of Paragloborotalia opima and Sphenolithus distentus and the LOs of Globigerinoides primordius and Pontosphaera enormis. Benthic foraminifera of the Lučenec Formation indicate a high productivity and oxygen-deplected environ-ments. The Oligocene-Miocene boundary in the Lučenec Formation was appointed by the HOs of Helicospahera recta and Dictyococcites bisectus. Foraminiferal markers of this boundary were established from the HO of Globigerina ciperoensis and the LO of G. ottnangiensis. The highest nannofossil dating in the Lučenec Formation is recorded by the LOs of Helicosphaera mediterranea (NN1 Zone) and Discoaster druggi (NN2 Zone). The uppermost part of the Lučenec Formation contained many Paratethys benthic foraminifera, such as Uvigerina posthantkeni.
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Pint, Anna, Max Engel, Sandra Melzer, Peter Frenzel, Birgit Plessen, and Helmut Brückner. "How To Discriminate Athalassic and Marginal Marine Microfaunas: Foraminifera and Other Fossils from an Early Holocene Continental Lake in Northern Saudi Arabia." Journal of Foraminiferal Research 47, no. 2 (April 1, 2017): 175–87. http://dx.doi.org/10.2113/gsjfr.47.2.175.
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Abstract The occurrence of athalassic foraminiferal species, along with the brackish-water ostracod Cyprideis torosa, the barnacle Amphibalanus amphitrite, and brackish-water gastropods, prove the existence of a saline lake at Tayma, northern Saudi Arabia, during the early to mid-Holocene. Outcrops at the former shoreline, as well as a single sediment core, allow a reconstruction of the history of the main lake phase. Whereas these outcrops contain masses of calcareous micro- and macrofossils, the core from the modern sabkha does not. Four foraminiferal species were identified: Ammonia tepida is dominant, Quinqueloculina seminula is common, Flintinoides labiosa and Discorinopsis aguayoi are rare. Sieve-pore analysis and shell chemistry of C. torosa, as well as varying but generally high proportions of test anomalies (up to 50%) in foraminifers, indicate fluctuating, mostly hypersaline lacustrine conditions. We suggest, based on these results and on a literature overview on the worldwide distribution of Quaternary athalassic foraminifer taxa, that a combination of low diversity, exclusively marginal marine taxa, combined with occurrences of test anomalies >10% can be used to recognize athalassic saline waters in the fossil record.
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Bornemann, André, Sofie Jehle, Friederike Lägel, Arne Deprez, Maria Rose Petrizzo, and Robert P. Speijer. "Planktic foraminiferal response to an early Paleocene transient warming event and biostratigraphic implications." International Journal of Earth Sciences 110, no. 2 (February 22, 2021): 583–94. http://dx.doi.org/10.1007/s00531-020-01972-z.
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AbstractThe Latest Danian Event (LDE, ~ 62.2 Ma) is characterized by global changes in the carbon cycle as indicated by two negative δ13C excursions of up to ~ 1‰. These δ13C shifts are accompanied by a 2–3 °C warming of both surface and deep waters based on benthic and planktic foraminiferal δ18O measurements, and the LDE has, thus, been considered as a so-called hyperthermal event. The event lasted for 200 kyr and has been identified in various ocean basins and shallow marine settings. Here, we present a compilation of data from three deep-sea cores covering the Pacific, North and South Atlantic oceans as well as a southern Tethyan shelf section to document the response of planktic foraminifera assemblages to ocean warming. In all studied successions, we observe the disappearance of the planktic foraminifer genus Praemurica on a global scale that took place close to the onset of the LDE. Moreover, on the long run, praemuricids were contemporaneously replaced by morozovellids. Both the decline of Praemurica and a temperature increase started between 200 and 260 kyr before the LDE onset and were punctuated by the LDE itself. In this paper, we propose two mechanisms that have controlled the environmental changes associated with this event, (1) increased activity of the North Atlantic Igneous Province acting on long time-scales, and (2) changes of orbital parameters resulting in insolation changes on shorter time-scales.In contrast to a proposed muted benthic foraminiferal response, the planktic community has been substantially impacted by the LDE as indicated by changes in planktic foraminifera faunas and calcareous nannofossils. Finally, our quantitative and conventional approaches identifying stratigraphically important planktic foraminifera datum levels justify a revision of the upper Danian to lower Selandian planktic foraminifera biozonation.
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Ke, Xue, Baohua Li, Zongyan Zhang, Yi Wei, Fei Hu, Dongwen Fan, Li Sun, Jianlei Xie, Junjie Yu, and Huazhou Yao. "Post-glacial Foraminifera of the incised Yangtze paleo-valley and paleoenvironmental implications." Journal of Paleontology 91, no. 6 (August 23, 2017): 1102–22. http://dx.doi.org/10.1017/jpa.2017.66.
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AbstractThree gravity cores (LZK1, ZKA4, and CSJA6) from the incised Yangtze paleo-valley comprise a thick sequence of the post-glacial deposit. Nineteen genera (26 species) of the benthic foraminifers are described from these cores, with detailed down-core foraminiferal variations to investigate their paleoenvironmental implications. Three foraminiferal assemblages are recognized for the lower, middle, and upper parts of the cores respectively. The lower part is dominated byAmmonia beccariivar. andFlorilus decoruswith lower abundance and diversity. In the middle part, the foraminifers are abundant and diverse, dominated by bothAmmonia beccariivar. andElphidium advenum.Cavarotalia annectens,Pararotalia nipponica, and porcellaneous benthic foraminiferal forms are always present, sometimes abundant. The upper part is characterized by theAmmonia beccarii-Elphidium magellanicumassemblage, except for the Core ZKA4, which is barren of foraminifers in this interval. AMS14C dates and foraminiferal assemblages both confirm that the transgression-regression sequence in these cores belongs to the “Ammoniatransgression” during the Holocene. In addition to documenting the post-glacial sea-level fluctuations, the benthic foraminifers also reflect a warmer climate during the early–middle Holocene. The foraminiferal differences among the three cores can be used to interpret the influence of seawater during the post-glacial sea-level fluctuations. The area in the vicinity of Core ZKA4 was affected by marine water only during the middle Holocene, which was much shorter than the areas of the other cores.
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Bąk, Krzysztof, and Marta Bąk. "Foraminiferal and radiolarian biostratigraphy of the youngest (Late Albian through Late Cenomanian) sediments of the Tatra massif, Central Western Carpathians." Acta Geologica Polonica 63, no. 2 (June 1, 2013): 223–38. http://dx.doi.org/10.2478/agp-2013-0009.
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Abstract Bąk, K. and Bąk M. 2013. Foraminiferal and radiolarian biostratigraphy of the youngest (Late Albian through Late Cenomanian) sediments of the Tatra massif, Central Western Carpathians. Acta Geologica Polonica, 63 (2), 223-237. Warszawa. The foraminiferal and radiolarian biostratigraphy of selected sections of the Zabijak Formation, the youngest sediments of the Tatra massif (Central Western Carpathians), have been studied. Benthic foraminifers, mainly agglutinated species, occur abundantly and continuously throughout the studied succession, while planktic foraminifers are generally sparse. Five planktic and two benthic foraminiferal zones have been recognized. The marly part of the Zabijak Formation comprises the Pseudothalmanninella ticinensis (Upper Albian) through the Rotalipora cushmani (Upper Cenomanian) planktic foraminiferal zones, and the Haplophragmoides nonioninoides and Bulbobaculites problematicus benthic foraminiferal zones. The radiolarians were recognized exclusively in the Lower Cenomanian part of the formation.
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Missiaen, L., L. Wacker, B. C. Lougheed, L. Skinner, I. Hajdas, J. Nouet, S. Pichat, and C. Waelbroeck. "Radiocarbon Dating of Small-sized Foraminifer Samples: Insights into Marine sediment Mixing." Radiocarbon 62, no. 2 (March 9, 2020): 313–33. http://dx.doi.org/10.1017/rdc.2020.13.
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ABSTRACTRadiocarbon (14C) can be used to build absolute chronologies and reconstruct ocean ventilation over the last 40 ka. Sample size requirements have restricted 14C measurements in marine cores with low foraminifer content, impeding 14C-based studies focused on abrupt climate events. Recent developments have demonstrated that small-sized foraminifer samples can now be dated using a gas introduction system at the cost of a small decrease in precision. We explore the potential of gas measurements on benthic and planktonic foraminifers from core SU90-08 (43°03′1″N, 30°02′5″W, 3080 m). Gas measurements are accurate, reproducible within 2σ uncertainty and comparable to graphite measurements. Both techniques yield negative 14C benthic-planktonic (B-P) age-offsets after Heinrich event 1. We argue that negative B-P ages result from bioturbation and changes in foraminifer abundances, with the chance of negative B-P especially increased when the 14C age gradient between the deep and surface waters is decreased. Small-sized 14C measurements seem to capture the variance of the foraminifera age distribution, revealing the active mixing in those archives. Sediment deposition and mixing effects possibly pose a greater obstacle for past 14C-based dating and ocean ventilation reconstructions than the measurement precision itself, particularly in relatively low sedimentation rate settings.
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Langer, Martin R., and Harmeet Bagi. "Tubicolous polychaetes as substrates for epizoic foraminifera." Journal of Micropalaeontology 13, no. 2 (December 1, 1994): 132. http://dx.doi.org/10.1144/jm.13.2.132.
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Abstract. Associations of epizoic foraminifera and invertebrates are widespread and have been reported from polar to tropical and shallow to bathyal environments (Zumwalt & DeLaca, 1980). Their fossil record stretches far back into Palaeozoic times as documented by agglutinated foraminifera attached to crinoids in Silurian and Devonian reef deposits of Morocco and Gotland (Franzen, 1974). Strong preferences for filter-feeding hosts suggest that epizoic foraminifera benefit from increased nutritional resources accumulated in the immediate flow microhabitat (Langer & Long, 1994).In the course of a broader study on foraminifera/invertebrate associations, several hundred foraminifera attached to the outer wall of agglutinated tubes of various polychaetes (e.g. Sabella sp., Potamilla sp.) were collected from sediment samples dredged at 61 m depth off the University of California, Moss Landing Marine Laboratory (NW Pacific). Attached foraminifera display a remarkable mode to obtain and differentially cement grains from the host tube that previously has not been reported. Agglutinated polychaete tubes and fragments thereof may reach 2 cm or more in length and are composed of fine sand, silt and micas cemented together by secreted organic material (Fig. 1). Tubes are typically orientated vertically in the mud and project above the sediment surface into the water column.NEW OBSERVATIONSExamination of agglutinated polychaete tubes revealed that their outer walls were commonly colonized by one to three foraminiferans (Figs 1–3, tube diameter 1.5–2.0 mm). The epizoic foraminiferal fauna comprised exclusively agglutinated taxa and included the following species: Alveophragmium advenum (Cushman), Textularia abbreviata Lalicker & McCulloch, Textularia schencki . . .
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Schiebel, R., and A. Movellan. "First-order estimate of the planktic foraminifer biomass in the modern global oceans." Earth System Science Data Discussions 5, no. 1 (April 27, 2012): 243–80. http://dx.doi.org/10.5194/essdd-5-243-2012.
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Abstract. Planktic foraminifera are heterotrophic mesozooplankton of global marine abundance. The position of planktic foraminifers in the marine food web is different compared to other protozoans and ranges above the base of heterotrophic consumers. Being secondary producers with an omnivorous diet, which ranges from algae to small metazoans, planktic foraminifers are not limited to a single food source, and are assumed to occur at a balanced abundance displaying the overall marine biological productivity at a regional scale. We have calculated the assemblage carbon biomass from data on standing stocks between the sea surface and 2500 m water depth, based on 754 protein-biomass data of 21 planktic foraminifer species and morphotypes, produced with a newly developed method to analyze the protein biomass of single planktic foraminifer specimens. Samples include symbiont bearing and symbiont barren species, characteristic of surface and deep-water habitats. Conversion factors between individual protein-biomass and assemblage-biomass are calculated for test sizes between 72 and 845 μm (minimum diameter). The calculated assemblage biomass data presented here include 1057 sites and water depth intervals. Although the regional coverage of database is limited to the North Atlantic, Arabian Sea, Red Sea, and Caribbean, our data include a wide range of oligotrophic to eutrophic waters covering six orders of magnitude of assemblage biomass. A first order estimate of the global planktic foraminifer biomass from average standing stocks (>125 μm) ranges at 8.5–32.7 Tg C yr−1 (i.e. 0.008–0.033 Gt C yr−1), and might be more than three time as high including the entire fauna including neanic and juvenile individuals adding up to 25–100 Tg C yr−1. However, this is a first estimate of regional planktic-foraminifer assemblage-biomass (PFAB) extrapolated to the global scale, and future estimates based on larger data-sets might considerably deviate from the one presented here. This paper is supported by, and a contribution to the Marine Ecosystem Data project (MAREDAT). Data are available from www.pangaea.de (http://doi.pangaea.de/10.1594/PANGAEA.777386).
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Dämmer, Linda K., Lennart de Nooijer, Erik van Sebille, Jan G. Haak, and Gert-Jan Reichart. "Evaluation of oxygen isotopes and trace elements in planktonic foraminifera from the Mediterranean Sea as recorders of seawater oxygen isotopes and salinity." Climate of the Past 16, no. 6 (November 30, 2020): 2401–14. http://dx.doi.org/10.5194/cp-16-2401-2020.
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Abstract. The Mediterranean Sea is characterized by a relatively strong west to east salinity gradient, which makes it an area suitable for testing the effect of salinity on foraminiferal shell geochemistry. We collected living specimens of the planktonic foraminifer Globigerinoides ruber albus to analyse the relation between element ∕ Ca ratios, stable oxygen isotopes of their shells, and surface seawater salinity, isotopic composition and temperature. The oxygen isotopes of sea surface water also correlate with salinity in the Mediterranean during winter, which is when sampling for this study took place. Seawater oxygen and hydrogen isotopes are positively correlated in both the eastern and western Mediterranean Sea, although the relationship differs from previously reported values, especially in the eastern region. The slope between salinity and seawater oxygen isotopes is lower than previously published results. Still, despite the rather modest slope, seawater and foraminiferal carbonate oxygen isotopes are correlated in our dataset, albeit with large residuals and high residual variability. This scatter could be due to either biological variability in vital effects or environmental variability. Numerical models backtracking particles show that ocean-current-driven mixing of particles of different origins might dampen sensitivity and could result in an offset caused by horizontal transport. Results show that Na ∕ Ca is positively correlated with salinity and independent of temperature. As expected, foraminiferal Mg ∕ Ca increases with temperature, which is in line with earlier calibrations, and in the high salinity environment. By using living foraminifera during winter, the previously established Mg ∕ Ca–temperature calibration is extended to temperatures below 18 ∘C, which is a fundamental prerequisite of using single foraminifera for reconstructing past seasonality.
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Gasiński, M., and Alfred Uchman. "Latest Maastrichtian foraminiferal assemblages from the Husów region (Skole Nappe, Outer Carpathians, Poland)." Geologica Carpathica 60, no. 4 (August 1, 2009): 283–94. http://dx.doi.org/10.2478/v10096-009-0020-5.
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Latest Maastrichtian foraminiferal assemblages from the Husów region (Skole Nappe, Outer Carpathians, Poland) The Ropianka Formation (also known as the Inoceramian Beds) in the marginal part of the Skole Nappe (Husów region, the Gaj section) contains abundant, diverse and well preserved assemblages of Maastrichtian planktonic and benthic foraminiferids, assigned to the middle-upper part of the Gansserina gansseri Zone and to the Abathomphalus mayaroensis Zone. The composition of the assemblages indicates fluctuations of organic matter flux to the marginal part of the Skole Basin floor in the studied interval. The studied taxa are typical of the "transitional zone" between the Tethyan and the Boreal domains. The disappearance of planktonic foraminifers in the uppermost part of the section and appearance of some agglutinated taxa (Rzehakina fissistomata; abundant Conglophragmium irregularis and Glomospira charoides) points to a Paleocene age.
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Schiebel, R., and A. Movellan. "First-order estimate of the planktic foraminifer biomass in the modern ocean." Earth System Science Data 4, no. 1 (September 3, 2012): 75–89. http://dx.doi.org/10.5194/essd-4-75-2012.
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Abstract. Planktic foraminifera are heterotrophic mesozooplankton of global marine abundance. The position of planktic foraminifers in the marine food web is different compared to other protozoans and ranges above the base of heterotrophic consumers. Being secondary producers with an omnivorous diet, which ranges from algae to small metazoans, planktic foraminifers are not limited to a single food source, and are assumed to occur at a balanced abundance displaying the overall marine biological productivity at a regional scale. With a new non-destructive protocol developed from the bicinchoninic acid (BCA) method and nano-photospectrometry, we have analysed the protein-biomass, along with test size and weight, of 754 individual planktic foraminifers from 21 different species and morphotypes. From additional CHN analysis, it can be assumed that protein-biomass equals carbon-biomass. Accordingly, the average individual planktic foraminifer protein- and carbon-biomass amounts to 0.845 μg. Samples include symbiont bearing and symbiont-barren species from the sea surface down to 2500 m water depth. Conversion factors between individual biomass and assemblage-biomass are calculated for test sizes between 72 and 845 μm (minimum test diameter). Assemblage-biomass data presented here include 1128 sites and water depth intervals. The regional coverage of data includes the North Atlantic, Arabian Sea, Red Sea, and Caribbean as well as literature data from the eastern and western North Pacific, and covers a wide range of oligotrophic to eutrophic waters over six orders of magnitude of planktic-foraminifer assemblage-biomass (PFAB). A first order estimate of the average global planktic foraminifer biomass production (>125 μm) ranges from 8.2–32.7 Tg C yr−1 (i.e. 0.008–0.033 Gt C yr−1), and might be more than three times as high including neanic and juvenile individuals adding up to 25–100 Tg C yr−1. However, this is a first estimate of regional PFAB extrapolated to the global scale, and future estimates based on larger data sets might considerably deviate from the one presented here. This paper is supported by, and a contribution to the Marine Ecosystem Data project (MAREDAT). Data are available from http://www.pangaea.de (http://doi.pangaea.de/10.1594/PANGAEA.777386).
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Washington, Kirstin E., A. Joshua West, Boriana Kalderon-Asael, Joachim A. R. Katchinoff, Emily I. Stevenson, and Noah J. Planavsky. "Lithium isotope composition of modern and fossilized Cenozoic brachiopods." Geology 48, no. 11 (July 13, 2020): 1058–61. http://dx.doi.org/10.1130/g47558.1.
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Abstract Seawater lithium stable isotope ratios, represented by δ 7 Li sw (‰), hold key information about the evolution of global climate and the carbon cycle over geologic time. Reconstructions based on foraminifera suggest an ∼9‰ increase in δ 7 Li sw over the past 60 m.y., interpreted as reflecting changes in the silicate weathering regime that may have contributed to global cooling over this time. However, culture experiments suggest that vital effects in foraminifers might cause varied δ 7 Li fractionation that could have affected past records. Thus, other archives are needed to determine whether the observed rise in foraminifer δ 7 Li values over the Cenozoic indeed reflects secular changes in δ 7 Li sw . Such archives would also open possibilities for robust determination of δ 7 Li sw deeper in geologic time. We analyzed δ 7 Li compositions in modern brachiopods ( n = 34) and found a relatively narrow range of +24.2 ‰ to +28.8‰ (mean = +26.8‰; 1σ = 0.5‰), similar to the range reported for inorganic calcite precipitated from seawater. These results confirm that brachiopods are good candidates for providing a representative record of δ 7 Li sw . We present data from fossil specimens dating from 65 Ma to ca. 700 ka, finding that fossilized brachiopods record a similar magnitude of change in δ 7 Li sw as foraminifers. These results are the first to corroborate the ∼9‰ increase in Cenozoic δ 7 Li sw and open possibilities for generating robust records of δ 7 Li sw in deep time, prior to foraminifer evolution.
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Lesen, Amy E., and Jere H. Lipps. "What have natural and human changes wrought on the foraminifera of San Francisco Bay late Quaternary estuaries?" Quaternary Research 76, no. 2 (September 2011): 211–19. http://dx.doi.org/10.1016/j.yqres.2011.06.005.
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AbstractIn this study we compare the foraminifera of modern South San Francisco Bay with fossils from sediments of a previous estuary at 125 ka to provide a basis for interpreting the impact of natural and human change on the benthic ecosystem. All the species found in the Pleistocene sediments of this study are estuarine and/or shallow-water species occurring commonly in San Francisco Bay today, except for the introduced foraminifer Trochammina hadai, a native of Japan that was not found in samples taken in San Francisco Bay before 1983. The biodiversity and species composition of the fossil and modern assemblages before the introduction of T. hadai are nearly identical, suggesting that the environmental and physical changes in the 125,000-year-old and modern estuaries have not had a significant effect on the meiofauna of the Bay. In contrast, modern anthropogenic change in the form of species introductions has impacted the modern foraminiferal assemblage: T. hadai began to dominate the modern assemblage a decade after its introduction. Similar to the recorded impacts of introductions of marine metazoan invertebrate species, the dominance of T. hadai changed species proportions in the post-1980s foraminiferal assemblage, however no known extinctions in the native foraminiferal fauna occurred.
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Kostecki, Robert, and Teresa Radziejewska. "The foraminiferal record in the Holocene evolution of the Mecklenburg Bay (south-western Baltic Sea)." Oceanological and Hydrobiological Studies 50, no. 2 (June 1, 2021): 169–83. http://dx.doi.org/10.2478/oandhs-2021-0016.
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Abstract Foraminiferal assemblages were analyzed in a 620-cm long core retrieved from the central part of the Mecklenburg Bay (MB, south-western Baltic Sea) to aid in the reconstruction of environmental changes occurring in the area during the Holocene and to complement a set of previously investigated palaeoenvironmental proxies. A total of five foraminifera-based stratigraphic units were identified, including an initial 80-cm thick layer devoid of foraminifera. The next two units featured an increasing abundance of the foraminiferal assemblage dominated by the calcareous Ammonia group species. Nearly all the calcareous foraminifera found in the core were decalcified. Following the maximum abundance within the 470–410 cm layer, the foraminiferal abundance declined sharply and the assemblage’s dominance structure changed to domination of the agglutinated foraminiferal species, Eggerelloides scaber, which continued up to the top of the core and marked a pronounced shift in environmental conditions (shallower depth, lower salinity, more dynamic sedimentation conditions). The foraminifera-based stratigraphy of the core proved to be complementary to that emerging from previous analyses of diatoms and sediment geochemistry.
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Yadrenkin, A. V., A. S. Byakov, R. V. Kutygin, and A. V. Kopylova. "NEW DATES AND STRATIGRAPHICAL DISTRIBUTION OF FORAMINIFERS FROM PERMIAN-TRIASSIC BOUNDARY DEPOSITS IN THE SOUTH VERKHOYAN REGION." Tikhookeanskaya Geologiya 39, no. 5 (2020): 69–82. http://dx.doi.org/10.30911/0207-4028-2020-39-5-69-82.
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The first results made on the study of foraminifera from Permian-Triassic boundary deposits in the South Verkhoyan Region (the lower part of the Nekuchan Formation, the Suol section, the Setorym River basin, tributary of the Vostochnaya Khandyga River) are presented. The foraminifera are a new group for this section and were not used in paleontological stratigraphic studies before. The foraminiferal assemblage is represented exclusively by ammodiscids (genera Ammodiscus, Glomospira, and Glomospirella), among which Ammodiscus septentrionalis Gerke dominates. The distribution of foraminifera in the Suol section is compared with the previously constructed carbon isotope curve, which reflects global environmental changes. Three intervals are identified in the stratigraphic distribution of foraminifera. In the lower interval, foraminifera are relatively numerous and diverse. In the middle interval foraminifera were not detected; here the maximum negative values of the δ13Сorg isotope are also recorded. This interval, obviously, corresponds to the time of the main fauna extinction in the Tethyan basins. In the upper interval, a gradual recovery of the abundance and structure of the foraminiferal complex occurs. A comparative analysis of the distribution and dynamics of taxonomic rearrangements of foraminiferal associations in the Permian-Triassic deposits in the Suol section with Tethyan and Boreal sections was carried out, some general features and patterns are established. A brief description of four of foraminiferal species and a photo table with their image are given.
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Hayward, Bruce W., François Le Coze, Leen Vandepitte, and Bart Vanhoorne. "Foraminifera in the World Register of Marine Species (Worms) Taxonomic Database." Journal of Foraminiferal Research 50, no. 3 (July 1, 2020): 291–300. http://dx.doi.org/10.2113/gsjfr.50.3.291.
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ABSTRACT Most foraminiferal research is founded on sound taxonomy. To clearly communicate such research, similar species concepts and consistent use of names is desirable. As a contribution to this larger goal, the World Foraminifera Database (http://www.marinespecies.org/foraminifera) was set up in 2010 as a subset within the World Register of Marine Species (WoRMS). The purpose is to provide an authoritative, open-access inventory of all foraminiferal taxonomic names. The inventory is almost complete for both fossil and Recent foraminiferal taxa, containing 4932 generic and 55,884 species (including infraspecies) names. There are ∼61,000 genus-species combinations of which ∼54,600 are currently “accepted” species and infraspecies (with 9600 extant). Associated data includes 14,700 linked foraminiferal literature sources, ∼6600 images, and species-level links to many other databases and images, such as the Cushman Collection (Smithsonian Institution), American Museum of Natural History, Mikrotax (planktic foraminifera), GenBank, and Zootaxon. The WoRMS database is owned by the global taxonomic community and hosted and serviced by the Flanders Marine Institute (VLIZ), Belgium. We recommend that all researchers working with foraminifera both use and contribute to the World Foraminifera Database, as that will improve the accuracy of the database's content and save investigators many hours of searching elsewhere.
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Burke, Janet E., Willem Renema, Michael J. Henehan, Leanne E. Elder, Catherine V. Davis, Amy E. Maas, Gavin L. Foster, Ralf Schiebel, and Pincelli M. Hull. "Factors influencing test porosity in planktonic foraminifera." Biogeosciences 15, no. 21 (November 7, 2018): 6607–19. http://dx.doi.org/10.5194/bg-15-6607-2018.
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Abstract. The clustering of mitochondria near pores in the test walls of foraminifera suggests that these perforations play a critical role in metabolic gas exchange. As such, pore measurements could provide a novel means of tracking changes in metabolic rate in the fossil record. However, in planktonic foraminifera, variation in average pore area, density, and porosity (the total percentage of a test wall that is open pore space) have been variously attributed to environmental, biological, and taxonomic drivers, complicating such an interpretation. Here we examine the environmental, biological, and evolutionary determinants of pore characteristics in 718 individuals, representing 17 morphospecies of planktonic foraminifera from 6 core tops in the North Atlantic. Using random forest models, we find that porosity is primarily correlated to test surface area, test volume, and habitat temperature, key factors in determining metabolic rates. In order to test if this correlation arose spuriously through the association of cryptic species with distinct biomes, we cultured Globigerinoides ruber in three different temperature conditions, and found that porosity increased with temperature. Crucially, these results show that porosity can be plastic: changing in response to environmental drivers within the lifetime of an individual foraminifer. This demonstrates the potential of porosity as a proxy for foraminiferal metabolic rates, with significance for interpreting geochemical data and the physiology of foraminifera in non-analog environments. It also highlights the importance of phenotypic plasticity (i.e., ecophenotypy) in accounting for some aspects of morphological variation in the modern and fossil record.
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Boltovskoy, Esteban, Demetrio Boltovskoy, and Frederico Brandini. "Planktonic Foraminifera from southwestern Atlantic epipelagic waters: abundance, distribution and year-to-year variations." Journal of the Marine Biological Association of the United Kingdom 80, no. 2 (April 2000): 203–13. http://dx.doi.org/10.1017/s0025315499001794.
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The abundance and latitudinal and vertical (0-100 m) distribution of planktonic Foraminifera was investigated on the basis of 38 samples collected in November 1994 in the southwestern Atlantic Ocean (34-60°S, along 51-56°W). Mean foraminiferal densities were 1.5 ind. l−1 (range: 0.15.9 ind. l−1), with highest concentrations in subsurface waters (20-50 m). Couplings between the distribution of chlorophyll a and foraminiferal abundances were very loose. Distribution patterns of the 15 species recorded allowed 6 distinct areas to be defined along the transect surveyed. From north to south these are: Subtropical (dominated by Globigerinoides ruber and G. trilobus), Cold intrusion (Globigerinita uvula), Transitional-Subtropical and Transitional (Globigerina bulloides, Globigerina quinqueloba), Subantarctic (G. quinqueloba), and Antarctic (Neogloboquadrina pachyderma, left coiling). Close comparisons with the yields of a similar data set collected in November 1993 show very good agreement. Foraminiferal thermic régimes were also similar in 1993 and in 1994, but for some species significant differences with previous data were detected. While the southwards extensions of the ranges of warm water species are fairly well circumscribed by the Brazil current-influenced waters, several foraminifers widely used as indicators and palaeoindicators of cool waters (in particular Globigerina bulloides, Globigerina quinqueloba and Globigerinita uvula) were recorded in very significant numbers at temperatures as high as 20-24°C. The implication of these findings for hydrological, ecological, and palaeoecological interpretations is discussed.
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Smoleń, Jolanta. "Faunal dynamics of foraminiferal assemblages in the Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland." Acta Geologica Polonica 62, no. 3 (December 28, 2012): 403–19. http://dx.doi.org/10.2478/v10263-012-0023-x.
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ABSTRACT Smoleń, J. 2012. Faunal dynamics of foraminiferal assemblages in the Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland. Acta Geologica Polonica, 62(3), 403-419. Warszawa. The faunal dynamics of benthic foraminifera in the Middle Jurassic ore-bearing clays of Gnaszyn (Kraków- Częstochowa Upland, south-central Poland) are used to reconstruct sedimentary environments. Two types of foraminiferal assemblages, distinct in their quantitative and qualitative composition, were distinguished; type I assemblages, characterizing intervals between horizons with sideritic concretions; and type II assemblages, characterising horizons with sideritic concretions. Benthic foraminifers were further subdivided into eight ecological morphogroups, based on their morphological features and micro-habitats. Type I assemblages consist mostly of plano/concavo-convex, small-sized epifaunal morphotypes, with a restricted occurrence of shallow infaunal forms and a scarcity of deep infaunal taxa, which suggests low-oxygen conditions in both sediment and bottom waters, and a high sedimentation rate in an outer shelf environment. Type II assemblages are characterized by high taxonomic diversity, high specimen abundance and variability of epifaunal and infaunal morphotypes representing a mixed group of specialized feeding strategies. This suggests optimum living conditions controlled by a lower sedimentation rate, relatively well-oxygenated bottom waters and sufficient or high food supply.
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Fischel, Andrea, Marit-Solveig Seidenkrantz, and Bent Vad Odgaard. "Benthic foraminiferal assemblages and test accumulation in coastal microhabitats on San Salvador, Bahamas." Journal of Micropalaeontology 37, no. 2 (November 14, 2018): 499–518. http://dx.doi.org/10.5194/jm-37-499-2018.
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Abstract. Benthic foraminiferal populations were studied in a shallow bay of San Salvador Island, the Bahamas. Surface sediments and marine macrophytes were collected from 14 sample sites along a 500 m transect at Grahams Harbour to investigate the foraminiferal assemblage in each microhabitat and to test the link between dead foraminiferal test accumulation patterns and living epiphytic and sedimentary foraminiferal assemblages, macrophyte distribution, and environmental gradients. The analyses include grain size measurements, macrophyte biomass quantification, and qualitative and quantitative studies of benthic foraminifera. The foraminifera found attached to macrophytes differed between macrophyte habitats. However, a correlation between these living communities and the dead assemblages in the sediments at the same sites could not be observed. Principal component analysis (PCA) and redundancy analysis (RDA) suggest that the presence of the macroalgae Halimeda explains 16 % of the residual faunal variation in the dead foraminiferal assemblage after the effects of sorting according to fall speed are partialled out. The RDA also reflects a positive correlation between foraminifera larger than 1.0 mm in diameter and the 0.25–0.5 mm sediment grain size, indicating sedimentological processes as the main factor controlling the sedimentary epiphytic foraminiferal assemblages. These sedimentary processes overprint most effects of ecological features or macrophyte-specific association.
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SILVA, WAGNER G., GEISE S. A. ZERFASS, PAULO A. SOUZA, and JAVIER HELENES. "Biochronostratigraphy and paleoenvironment analysis of Neogene deposits from the Pelotas Basin (well 2-TG-96-RS), Southernmost Brazil." Anais da Academia Brasileira de Ciências 87, no. 3 (August 25, 2015): 1565–82. http://dx.doi.org/10.1590/0001-3765201520140584.
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This paper presents the integration of micropaleontological (palynology and foraminifera) and isotopic (87Sr/86Sr) analysis of a selected interval from the well 2-TG-96-RS, drilled on the onshore portion of the Pelotas Basin, Rio Grande do Sul, Brazil. A total of eight samples of the section between 140.20 and 73.50 m in depth was selected for palynological analysis, revealing diversified and abundant palynomorph associations. Species of spores, pollen grains and dinoflagellate cysts are the most common palynomorphs found. Planktic and benthic calcareous foraminifera were recovered from the lowest two levels of the section (140.20 and 134.30 m). Based on the stratigraphic range of the species of dinoflagellate cysts and sporomorphs, a span age from Late Miocene to Early Pliocene is assigned. The relative age obtained from the 87Sr/86Sr ratio in shells of calcareous foraminifers indicates a Late Miocene (Messinian) correspondence, corroborating the biostratigraphic positioning performed with palynomorphs. Paleoenvironmental interpretations based on the quantitative distribution of organic components (palynomorphs, phytoclasts and amorphous organic matter) throughout the section and on foraminiferal associations indicate a shallow marine depositional environment for the section. Two palynologicals intervals were recognized based on palynofacies analysis, related to middle to outer shelf (140.20 to 128.90 m) and inner shelf (115.75 to 73.50 m) conditions.
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Wit, J. C., L. J. de Nooijer, C. Barras, F. J. Jorissen, and G. J. Reichart. "A reappraisal of the vital effect in cultured benthic foraminifer <I>Bulimina marginata</I> on Mg/Ca values: assessing temperature uncertainty relationships." Biogeosciences 9, no. 9 (September 27, 2012): 3693–704. http://dx.doi.org/10.5194/bg-9-3693-2012.
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Abstract. The reconstruction of past temperatures is often achieved through measuring the Mg/Ca value of foraminiferal test carbonate. The diversity in foraminiferal Mg/Ca–temperature calibrations suggests that there is also a biological control on this proxy. This study presents a new Mg/Ca–temperature calibration for the benthic foraminifer Bulimina marginata, based on cultures under a range of temperatures (4–14 °C). Measured Mg/Ca values for B. marginata correlate with temperature (Mg/Ca = (1.10 ± 0.10) e(0.045±0.009)T, R2 = 0.28 p < 0.01). The inter-individual variability is, however, also significant (standard deviation is 10–35% of the average). Before applying this or any calibration, the effect of the inter-individual variability on the accuracy of the Mg/Ca–temperature calibration has to be evaluated. The inter-individual variability is quantified and split into three components, namely (1) an analytical error, (2) an environmental effect and (3) a vital effect. The effect of inter-individual variability on the accuracy of Mg/Ca–temperature calibrations depends on the sensitivity of the calibration used and the number of individuals measured (temperature uncertainty = (0.33 · N−0.50)/sensitivity). The less sensitive a calibration, the greater is the impact of inter-individual variability, which can partly be circumvented by measuring more individuals. This study shows the link between inter-individual variability and sensitivity and quantifies their influence on the accuracy of Mg/Ca–temperature calibrations. Differences in the sensitivity of the Mg/Ca–temperature calibration of foraminifera may depend on the environmental conditions in which foraminifera live and their concurring ecological strategies.
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Wit, J. C., L. J. de Nooijer, M. Wolthers, and G. J. Reichart. "A novel salinity proxy based on Na incorporation into foraminiferal calcite." Biogeosciences Discussions 10, no. 3 (March 28, 2013): 6039–63. http://dx.doi.org/10.5194/bgd-10-6039-2013.
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Abstract. Salinity and temperature determine seawater density and differences in both thereby control global themohaline circulation. Whereas numerous proxies have been calibrated and applied to reconstruct temperature, a direct and independent proxy for salinity is still missing. Ideally, a new proxy for salinity should target one of the direct constituents of dissolved salt, such as [Na+] or [Cl−]. This study investigates the impact of salinity on foraminiferal Na/Ca values by laser ablation ICP-MS analyzes of specimens of the benthic foraminifer Ammonia tepida cultured at a range of salinities (30.0–38.6). Foraminifera at lower salinities (30.0 and 32.5) added more chambers (10–11) to their test over the course of the experiment than foraminifera cultured under higher salinity (36.1, 7–8 chambers, and 38.6, 6–7 chambers), suggesting that lower salinity promotes growth rates in this species. The Na/Ca of cultured specimens correlates significantly with seawater salinity (Na/Ca = 0.22S − 0.75, R2 = 0.96, p < 0.01) and size. Values for Na/Ca and DNa vary between 5.17 and 9.29 mmol mol−1 and 0.12–0.16 × 10−3, which is similar to inorganic precipitated calcite. The significant correlation between test size and Na/Ca results from co-variation with salinity. This implies that foraminiferal Na/Ca may well be a robust and independent proxy for salinity, enabling independent salinity reconstruction. The quantified effect of salinity on Mg/Ca in our culture experiment, furthermore allows a direct correction for the bias in Mg/Ca based temperature reconstructions caused by differences in salinity.
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Aurahs, Ralf, Markus GÖker, Guido W. Grimm, Vera Hemleben, Christoph Hemleben, Ralf Schiebel, and Michal Kučera. "Using the Multiple Analysis Approach to Reconstruct Phylogenetic Relationships among Planktonic Foraminifera from Highly Divergent and Length-polymorphic SSU rDNA Sequences." Bioinformatics and Biology Insights 3 (January 2009): BBI.S3334. http://dx.doi.org/10.4137/bbi.s3334.
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The high sequence divergence within the small subunit ribosomal RNA gene (SSU rDNA) of foraminifera makes it difficult to establish the homology of individual nucleotides across taxa. Alignment-based approaches so far relied on time-consuming manual alignments and discarded up to 50% of the sequenced nucleotides prior to phylogenetic inference. Here, we investigate the potential of the multiple analysis approach to infer a molecular phylogeny of all modern planktonic foraminiferal taxa by using a matrix of 146 new and 153 previously published SSU rDNA sequences. Our multiple analysis approach is based on eleven different automated alignments, analysed separately under the maximum likelihood criterion. The high degree of congruence between the phylogenies derived from our novel approach, traditional manually homologized culled alignments and the fossil record indicates that poorly resolved nucleotide homology does not represent the most significant obstacle when exploring the phylogenetic structure of the SSU rDNA in planktonic foraminifera. We show that approaches designed to extract phylogenetically valuable signals from complete sequences show more promise to resolve the backbone of the planktonic foraminifer tree than attempts to establish strictly homologous base calls in a manual alignment.
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Salmon, K. H., P. Anand, P. F. Sexton, and M. Conte. "Upper ocean mixing controls the seasonality of planktonic foraminifer fluxes and associated strength of the carbonate pump in the oligotrophic North Atlantic." Biogeosciences 12, no. 1 (January 13, 2015): 223–35. http://dx.doi.org/10.5194/bg-12-223-2015.
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Abstract. Oligotrophic regions represent up to 75% of Earth's open-ocean environments. They are thus areas of major importance in understanding the plankton community dynamics and biogeochemical fluxes. Here we present fluxes of total planktonic foraminifera and 11 planktonic foraminifer species measured at the Oceanic Flux Program (OFP) time series site in the oligotrophic Sargasso Sea, subtropical western North Atlantic Ocean. Foraminifera flux was measured at 1500 m water depth, over two ~ 2.5-year intervals: 1998–2000 and 2007–2010. We find that foraminifera flux was closely correlated with total mass flux, carbonate and organic carbon fluxes. We show that the planktonic foraminifera flux increases approximately 5-fold during the winter–spring, contributing up to ~ 40% of the total carbonate flux. This was primarily driven by increased fluxes of deeper-dwelling globorotaliid species, which contributed up to 90% of the foraminiferal-derived carbonate during late winter–early spring. Interannual variability in total foraminifera flux, and in particular fluxes of the deep-dwelling species (Globorotalia truncatulinoides, Globorotalia hirsuta and Globorotalia inflata), was related to differences in seasonal mixed layer dynamics affecting the strength of the spring phytoplankton bloom and export flux, and by the passage of mesoscale eddies. As these heavily calcified, dense carbonate tests of deeper-dwelling species (3 times denser than surface dwellers) have greater sinking rates, this implies a high seasonality of the biological carbonate pump in oligotrophic oceanic regions. Our data suggest that climate cycles, such as the North Atlantic Oscillation, which modulates nutrient supply into the euphotic zone and the strength of the spring bloom, may also in turn modulate the production and flux of these heavily calcified deep-dwelling foraminifera by increasing their food supply, thereby intensifying the biological carbonate pump.
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Norris, Richard D. "Symbiosis as an evolutionary innovation in the radiation of Paleocene planktic foraminifera." Paleobiology 22, no. 4 (1996): 461–80. http://dx.doi.org/10.1017/s0094837300016468.
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Symbioses are often regarded as an important means for the creation of evolutionary novelty as well as a trigger for the abrupt appearance of higher taxa. The fossil record of foraminifer-algal symbiosis suggests that the appearance of this ecological association contributed to the radiation of Paleogene planktic foraminifera. Isotopic evidence shows that photosymbiosis evolved in synchrony with a major diversification of trochospiral planktic foraminifera about 3.5 m.y. after the end-Cretaceous extinction. In modern planktic foraminifera, photosymbiotic species tend to have more cosmopolitan distributions than asymbiotic foraminifera and a greater ability to withstand periods of nutrient stress. The simultaneous taxonomic radiation and acquisition of photosymbiosis are evidence that the ecological strategy permitted Paleocene foraminifera to expand their niche in pelagic environments by diversifying into low-nutrient surface waters.A comparison of the species longevities of Neogene and Paleogene symbiotic clades suggests that photosymbiosis does not regulate the characteristic rate of taxonomic turnover in clades after they appear. Species longevities are much shorter in Paleocene and Eocene photosymbiotic morphospecies than they are among photosymbiotic Neogene clades; apparently photosymbiosis does not exert a significant control over long-term evolutionary rates. In addition, the absence of a characteristic morphology associated with photosymbiosis in Cenozoic planktic foraminifera suggests that morphology, as with rate of evolutionary turnover, is linked to symbiosis only because of common inheritance instead of a functional relationship. Although the coincidence between the acquisition of photosymbiosis and generic diversification does suggest a linkage between this ecology and the appearance of foraminiferal higher taxa, there is little indication at the present that symbioses control long-term morphological or ecological patterns within these groups after their appearance. Photosymbiosis, and other evolutionary innovations, may be more a catalyst for the differentiation of major groups than a predictable governor on evolutionary rates.
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Lowenstein, Tim K., and Bärbel Hönisch. "The Use of Mg/Ca as a Seawater Temperature Proxy." Paleontological Society Papers 18 (November 2012): 85–100. http://dx.doi.org/10.1017/s1089332600002564.
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The underlying basis for Mg/Ca paleothermometry is that the amount of magnesium in calcite precipitated from seawater is dependent on temperature. Here we review the state of the art of the Mg/Ca seawater paleotemperature proxy, summarized by the following: 1) Calcite, whether formed abiotically or biologically as foraminifera and ostracode shells, incorporates variable amounts of magnesium into the crystal structure. 2) Uptake of Mg varies positively with temperature. 3) The relationship between temperature and the amount of Mg in calcite has been quantified by experiments on synthetic calcite growth and by culture, core top, and sediment trap experiments using living organisms. 4) The most careful calibrations of the Mg/Ca paleothermometer have been done for planktic foraminifera, then benthic foraminifera; there are species-specific variations in the amount of Mg incorporated into foraminifera shells. 5) The Mg/Ca ratio of calcite from planktic foraminifera in deep-sea cores has been widely used to interpret sea surface temperatures. 6) Measurement of both Mg/Ca and δ18O in planktic foraminifera have been used to calculate δ18O in seawater, and after correction for global ice volume, salinity could be inferred. 7) Mg/Ca from benthic foraminifera have been used to reconstruct deep-sea temperatures and cooling of ~12° over the last 50 million years. 8) One problem with the Mg/Ca seawater temperature proxy is partial dissolution of foraminifer shells, which lowers the Mg/Ca, and leads to an underestimation of ocean temperature. Benthic foraminifers appear to be more resistant to partial dissolution. 9) Past changes in the Mg/Ca ratio of seawater are an important factor in determining the amount of Mg in fossil skeletal calcite, and thus add another variable to the Mg/Ca temperature proxy. All Mg/Ca paleotemperature studies on fossil calcite older than Pleistocene should take into account the Mg/Ca of the seawater from which it precipitated.
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Gottschalk, Julia, Sönke Szidat, Elisabeth Michel, Alain Mazaud, Gary Salazar, Michael Battaglia, Jörg Lippold, and Samuel L. Jaccard. "Radiocarbon Measurements of Small-Size Foraminiferal Samples with the Mini Carbon Dating System (MICADAS) at the University of Bern: Implications for Paleoclimate Reconstructions." Radiocarbon 60, no. 2 (March 21, 2018): 469–91. http://dx.doi.org/10.1017/rdc.2018.3.
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ABSTRACTRadiocarbon (14C) measurements of foraminifera often provide the only absolute age constraints in marine sediments. However, they are often challenging as their reliability and accuracy can be compromised by reduced availability of adequate sample material. New analytical advances using the MIni CArbon DAting System (MICADAS) allow 14C dating of very small samples, circumventing size limitations inherent to conventional 14C measurements with accelerator mass spectrometry (AMS). Here we use foraminiferal samples and carbonate standard material to assess the reproducibility and precision of MICADAS 14C analyses, quantify contamination biases, and determine foraminiferal 14C blank levels. The reproducibility of conventional 14C ages for our planktic (benthic) foraminiferal samples from gas measurements is 200 (130) yr, and has good precision as illustrated by the agreement between both standards and their reference values as well as between small gas- and larger graphitized foraminiferal samples (within 100±60 yr). We observe a constant contamination bias and slightly higher 14C blanks for foraminifera than for carbonate reference materials, limiting gas (graphite) 14C age determinations for foraminifera from our study sites to ~38 (~42) kyr. Our findings underline the significance of MICADAS gas analyses for 14C on smaller-than-conventional sized foraminiferal samples for paleoclimate reconstructions and dating.
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Gajardo, Nathalie, and Margarita Marchant. "Variaciones estacionales de los foraminiferos planctonicos durante 2005 2006 frente a Iquique (20ºS) y Concepcion (36ºS), Chile." Latin American Journal of Aquatic Research 40, no. 2 (July 10, 2012): 376–88. http://dx.doi.org/10.3856/vol40-issue2-fulltext-12.
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