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1
Emiliani, Cesare. "Planktic/planktonic, nektic/nektonic, benthic/benthonic." Journal of Paleontology 65, no. 2 (March 1991): 329. http://dx.doi.org/10.1017/s0022336000020576.
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2
Lam, Adriane R., and R. Mark Leckie. "Late Neogene and Quaternary diversity and taxonomy of subtropical to temperate planktic foraminifera across the Kuroshio Current Extension, northwest Pacific Ocean." Micropaleontology 66, no. 3 (2020): 177–268. http://dx.doi.org/10.47894/mpal.66.3.01.
Повний текст джерелаАнотація:
Patterns of diversity in the modern planktic foraminifera indicate a latitudinal diversity gradient (LDG), which peaks in the mid-latitude regions. Plankton distributional patterns are oftenmost strongly associated with temperature and are expected to change in response to expanded tropical water masses. Defining the underlying causes of climatic and oceanographic processes, however, requires detailed, local-scale diversity curves and evolutionary metrics, as well as solid taxonomic concepts of planktic foraminifera, to test the oceanographic processes driving evolution ofmarine plankton. Currently, diversity estimates for the planktic foraminifera are mainly based on global datasets skewed towards tropical to subtropical sites and conducted at coarse resolutions that hamper investigations of evolutionary processes, especially for short-lived climate perturbations. Here, we present 10-kyr resolution diversity curves and 25-kyr resolution local first appearance and extirpation rates of planktic foraminifera for four Ocean Drilling Program sites that extend from the temperate northern edge of the modern-day position of the Kuroshio Current Extension (KCE) to the tropics. We provide an updated taxonomic review of late Neogene planktic foraminiferal species from within the influence of the KCE. These data allow for investigations of the western Pacific LDG and patterns of evolution through the late Neogene in response to tectonic and climate events. Our results indicate that a mid-latitude diversity peak has been prominent in the western Pacific since at least 12.1Ma, with highest diversity generally on the northern edge of the KCE. These data contradict previous studies indicating highest diversity is located +/- 20 degrees, as our data reveal highest diversity for the planktic foraminifera at +/- 35 degrees N likely due to strong seasonality. Development of the modern North Pacific gyre system due to closure of the Central American Seaway and constriction of the Indonesian Throughflow increased the LDG between the tropics and the northernmost site, likely in response to KCE intensification. Diversity was only slightly affected during the mid-Piacenzian Warm Period (approx. 3.2-2.9Ma),with diversity gradients between the equatorial site and southernmost mid-latitude sites becoming similar, perhaps indicating a weaker thermal gradient developing in the northwest Pacific as the KCE and warmer waters were displaced northwards.With intensification of Northern Hemisphere glaciation came a decrease in diversity at the northernmost site, hypothesized to be caused by subtropical gyre constriction and southward displacement of subpolar surface waters. The beginning of the mid-Pleistocene transition marks an increase in diversity gradients, especially between the northernmost and tropical sites. A detailed taxonomic evaluation of planktic foraminiferal species has led to synonymization of what we consider regional morphological variants, as well as revised taxonomic concepts of key subtropical to temperate late Neogene planktic foraminifera. Scanning electron micrographs capture the morphological variability within a species concept for the first time in great detail for this part of the world ocean. These data and updated taxonomic concepts provide a framework for future studies to link evolutionary patterns with high-resolution geochemical and sedimentological data to further interpret localized drivers of diversification in the planktic foraminifera.
3
Tapia, Raúl, Sze Ling Ho, Hui-Yu Wang, Jeroen Groeneveld, and Mahyar Mohtadi. "Contrasting vertical distributions of recent planktic foraminifera off Indonesia during the southeast monsoon: implications for paleoceanographic reconstructions." Biogeosciences 19, no. 13 (July 7, 2022): 3185–208. http://dx.doi.org/10.5194/bg-19-3185-2022.
Повний текст джерелаАнотація:
Abstract. Planktic foraminifera are widely used in paleoceanographic and paleoclimatic studies. The accuracy of such reconstructions depends on our understanding of the organisms' ecology. Here we report on field observations of planktic foraminiferal abundances (>150 µm) from five depth intervals between 0–500 m water depth at 37 sites in the eastern tropical Indian Ocean. The total planktic foraminiferal assemblage here comprises 29 morphospecies, with 11 morphospecies accounting for 90 % of the total assemblage. Both species composition and dominance in the net samples are broadly consistent with the published data from the corresponding surface sediments. The abundance and vertical distribution of planktic foraminifera are low offshore western Sumatra and increase towards offshore southern Java and the Lesser Sunda Islands (LSI). Average living depth of Trilobatus trilobus, Globigerinoides ruber, and Globigerina bulloides increases eastward, while that of Neogloboquadrina dutertrei, Pulleniatina obliquiloculata, and Globorotalia menardii remains constant. We interpret the overall zonal and vertical distribution patterns in planktic foraminiferal abundances as a response to the contrasting upper-water-column conditions during the southeast monsoon, i.e., oligotrophic and stratified offshore Sumatra (non-upwelling) vs. eutrophic and well mixed offshore Java–LSI (upwelling). Overall, the inferred habitat depths of selected planktic foraminifera species show a good agreement with those from sediment trap samples and from surface sediments off Sumatra, but not with those from surface sediments off Java–LSI. The discrepancy might stem from the different temporal coverage of these sample types. Our findings highlight the need to consider how foraminiferal assemblages and ecology vary on shorter timescales, i.e., from “snapshots” of the water column captured by a plankton net to seasonal and interannual variability as recorded in sediment traps, and how these changes are transferred and preserved in deep-sea sediments.
4
Singh, Ashutosh K., and Devesh K. Sinha. "Plio-Pleistocene Planktic Foraminiferal Biochronology of ODP Site 762B, Exmouth Plateau, Southeast Indian Ocean." Journal of Foraminiferal Research 52, no. 4 (October 1, 2022): 248–63. http://dx.doi.org/10.2113/gsjfr.52.4.248.
Повний текст джерелаАнотація:
ABSTRACT The Indonesian Throughflow region connects the tropical Pacific Ocean with the eastern Indian Ocean, and variability of the Throughflow during the Plio-Pleistocene has been related to major climate shifts at the global level. Planktic foraminiferal biostratigraphy integrated with magnetochronology provides a robust time framework for assigning age control to major paleoceanographic events. Understanding of the coupled histories of the El Niño Southern Oscillation, Western Pacific Warm Pool, Indonesian Throughflow, and the eastern Indian Ocean has greatly benefitted from the chronological framework provided by planktic foraminiferal biostratigraphies from these regions. Ocean Drilling Program (ODP) Hole 762 lies under the influence of the Leeuwin Current, originating from the Indonesian Throughflow. Multiproxy data have been collected from Hole 762B and other nearby sites for paleoceanographic interpretation. However, a detailed planktic foraminiferal biostratigraphy integrated with magnetochronology is not available from this site. We provide here the sequential order of planktic foraminiferal First Occurrence (FO) and Last Occurrence (LO) events, which allowed us to divide the examined section into seven biostratigraphic zones. The biostratigraphy was integrated with magnetostratigraphy using revised ages of magnetochrons, which yielded biochronological age estimates for planktic foraminiferal events. A major planktonic faunal turnover between 3.4 and 2.7 Ma is probably related to the onset of the Northern Hemisphere glaciation and related changes in the Indonesian Throughflow. We have compared our numerical age estimates with published ages from other parts of the world. The diachronism observed probably is related to the local oceanographic setting of ODP Hole 762B, which has been alternatively influenced by changing strengths of the warm Leeuwin Current and the cold west Australian Current. The biochronology established here will be useful for correlating paleoceanographic events in the region.
5
Schiebel, Ralf, and Christoph Hemleben. "Modern planktic foraminifera." Paläontologische Zeitschrift 79, no. 1 (March 2005): 135–48. http://dx.doi.org/10.1007/bf03021758.
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6
Emiliani, Cesare. "Planktic et al." Marine Micropaleontology 18, no. 1-2 (November 1991): 3. http://dx.doi.org/10.1016/0377-8398(91)90003-o.
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7
D'Hondt, Steven, and James C. Zachos. "Cretaceous foraminifera and the evolutionary history of planktic photosymbiosis." Paleobiology 24, no. 4 (1998): 512–23. http://dx.doi.org/10.1017/s0094837300020133.
Повний текст джерелаАнотація:
Ecotypic correlations between stable isotopic signals and skeletal size indicate that some Late Cretaceous serial planktic foraminifera were strongly photosymbiotic. In contrast, coeval trochospiral planktic foraminifera do not exhibit the isotope/size signatures that typify strongly photosymbiotic species. Comparison to Cenozoic taxa demonstrates that photosymbiosis has recurred throughout planktic foraminiferal history and has evolved independently in superfamilies characterized by very different gross skeletal morphologies. The historical contingency of that evolution is illustrated by the consequences of the Cretaceous/Paleogene mass extinction, which terminated the Cretaceous lineages of photosymbiotic planktic foraminifera but did not permanently extinguish photosymbiont reliance by planktic foraminifera.
8
Lam, Adriane R., Martin P. Crundwell, R. Mark Leckie, James Albanese, and Jacob P. Uzel. "Diachroneity Rules the Mid-Latitudes: A Test Case Using Late Neogene Planktic Foraminifera across the Western Pacific." Geosciences 12, no. 5 (April 26, 2022): 190. http://dx.doi.org/10.3390/geosciences12050190.
Повний текст джерелаАнотація:
Planktic foraminifera are commonly used for first-order age control in deep-sea sediments from low-latitude regions based on a robust tropical–subtropical zonation scheme. Although multiple Neogene planktic foraminiferal biostratigraphic zonations for mid-latitude regions exist, quantification of diachroneity for the species used as datums to test paleobiogeographic patterns of origination and dispersal is lacking. Here, we update the age models for seven southwest-Pacific deep-sea sites using calcareous nannofossil and bolboform biostratigraphy and magnetostratigraphy, and use 11 sites between 37.9° N and 40.6° S in the western Pacific to correlate existing planktic foraminiferal biozonations and quantify the diachroneity of species used as datums. For the first time, northwest and southwest Pacific biozones are correlated and compared to the global tropical planktic foraminiferal biozonation. We find a high degree of diachroneity in the western Pacific, within and between the northwest and southwest regions, and between the western Pacific and the tropical zonation. Importantly, some datums that are found to be diachronous between regions have reduced diachroneity within regions. Much work remains to refine regional planktic foraminiferal biozonations and more fully understand diachroneity between the tropics and mid-latitudes. This study indicates that diachroneity is the rule for Late Neogene planktic foraminifera, rather than the exception, in mid-latitude regions.
9
Lam, Adriane R., Martin P. Crundwell, R. Mark Leckie, James Albanese, and Jacob P. Uzel. "Diachroneity Rules the Mid-Latitudes: A Test Case Using Late Neogene Planktic Foraminifera across the Western Pacific." Geosciences 12, no. 5 (April 26, 2022): 190. http://dx.doi.org/10.3390/geosciences12050190.
Повний текст джерелаАнотація:
Planktic foraminifera are commonly used for first-order age control in deep-sea sediments from low-latitude regions based on a robust tropical–subtropical zonation scheme. Although multiple Neogene planktic foraminiferal biostratigraphic zonations for mid-latitude regions exist, quantification of diachroneity for the species used as datums to test paleobiogeographic patterns of origination and dispersal is lacking. Here, we update the age models for seven southwest-Pacific deep-sea sites using calcareous nannofossil and bolboform biostratigraphy and magnetostratigraphy, and use 11 sites between 37.9° N and 40.6° S in the western Pacific to correlate existing planktic foraminiferal biozonations and quantify the diachroneity of species used as datums. For the first time, northwest and southwest Pacific biozones are correlated and compared to the global tropical planktic foraminiferal biozonation. We find a high degree of diachroneity in the western Pacific, within and between the northwest and southwest regions, and between the western Pacific and the tropical zonation. Importantly, some datums that are found to be diachronous between regions have reduced diachroneity within regions. Much work remains to refine regional planktic foraminiferal biozonations and more fully understand diachroneity between the tropics and mid-latitudes. This study indicates that diachroneity is the rule for Late Neogene planktic foraminifera, rather than the exception, in mid-latitude regions.
10
Sarnthein, Michael, Sven Balmer, Pieter M. Grootes, and Manfred Mudelsee. "Planktic and Benthic 14C Reservoir Ages for Three Ocean Basins, Calibrated by a Suite of 14C Plateaus in the Glacial-to-Deglacial Suigetsu Atmospheric 14C Record." Radiocarbon 57, no. 1 (2015): 129–51. http://dx.doi.org/10.2458/azu_rc.57.17916.
Повний текст джерелаАнотація:
This article presents a compilation of planktic and benthic 14C reservoir ages for the Last Glacial Maximum (LGM) and early deglacial from 11 key sites of global ocean circulation in the Atlantic and Indo-Pacific Ocean. The ages were obtained by 14C plateau tuning, a robust technique to derive both an absolute chronology for marine sediment records and a high-resolution record of changing reservoir/ventilation ages (Δ14C values) for surface and deep waters by comparing the suite of planktic 14C plateaus of a sediment record with that of the atmospheric 14C record. Results published thus far have used as atmospheric 14C reference U/Th-dated corals, the Cariaco planktic record, and speleothems. We have now used the varve-counted atmospheric 14C record of Lake Suigetsu terrestrial macrofossils to recalibrate the boundary ages and reservoir ages of the seven published records directly to an atmospheric 14C record. In addition, the results for four new cores and further planktic results for four published records are given. Main conclusions from the new compilation are the following: (1) The Suigetsu atmospheric 14C record on its varve-counted timescale reflects all 14C plateaus, their internal structures, and relative length previously identified, but implies a rise in the average 14C plateau age by 200–700 14C yr during the LGM and early deglacial times. (2) Based on different 14C ages of coeval atmospheric and planktic 14C plateaus, marine surface water Δ14C may have temporarily dropped to an equivalent of ∼0 yr in low-latitude lagoon waters, but reached >2500 14C yr both in stratified subpolar waters and in upwelled waters such as in the South China Sea. These values differ significantly from a widely assumed constant global planktic Δ14C value of 400 yr. (3) Suites of deglacial planktic Δ14C values are closely reproducible in 14C records measured at neighboring core sites. (4) Apparent deep-water 14C ventilation ages (equivalents of benthic Δ14C), deduced from the sum of planktic Δ14C and coeval benthic-planktic 14C differences, vary from 500 up to >5000 yr in LGM and deglacial ocean basins.
11
Stoykova, Kristalina, Sava Juranov, and Marin Ivanov. "Calibration of calraceous nannofossils and planktonic foraminifers’ zonation in the Lower and Middle Paleocene of Bulgaria." Geologica Balcanica 35, no. 1-2 (June 30, 2005): 3–9. http://dx.doi.org/10.52321/geolbalc.35.1-2.3.
Повний текст джерелаАнотація:
This study represents first attempt to juxtapose and correlate the zonal schemes of calcareous nannofossils and planktonic foraminifers in the Lower and Middle Paleocene of Bulgaria. The calibration of the two schemes is accomplished in the most complete and continuous sedimentary succession of Byala Fm., cropping out in the sections around the village of Goritsa, Varna District. In the Danian Stage the presence of NP1-NP4 nannofossil zones as well as of the planktic foraminifera zones Pα, P1a, P1b, P1c, P3a is documented. In despite of the scarce paleontological data, the presence of P0 zone in basal Danian and P2 zone in the upper Danian is suggested. In the Selandian Stage NP5 and respectively P3b zones are evidenced with exceptionally rich plankton associations. The upper part of the section is incomplete due to the overthrusting of Upper Cretaceous sediments. The most important bio-events in both group are calibrated, thus enable higher biostratigraphic resolution and accuracy of dating.
12
Davis, C. V., M. P. S. Badger, P. R. Bown, and D. N. Schmidt. "The response of calcifying plankton to climate change in the Pliocene." Biogeosciences 10, no. 9 (September 30, 2013): 6131–39. http://dx.doi.org/10.5194/bg-10-6131-2013.
Повний текст джерелаАнотація:
Abstract. As a result of anthropogenic pCO2 increases, future oceans are growing warmer and lower in pH and oxygen, conditions that are likely to impact planktic communities. Past intervals of elevated and changing pCO2 and temperatures can offer a glimpse into the response of marine calcifying plankton to changes in surface oceans under conditions similar to those projected for the future. Here we present new records of planktic foraminiferal and coccolith calcification (weight and size) from Deep Sea Drilling Project Site 607 (mid-North Atlantic) and Ocean Drilling Program Site 999 (Caribbean Sea) from the Pliocene, the last time that pCO2 was similar to today, and extending through a global cooling event into the intensification of Northern Hemisphere glaciation (3.3 to 2.6 million years ago). Test weights of both surface-dwelling Foraminifera Globigerina bulloides and thermocline-dwelling Foraminifera Globorotalia puncticulata vary with a potential link to regional temperature variation in the North Atlantic, whereas in the tropics Globigerinoides ruber test weight remains stable. In contrast, reticulofenestrid coccoliths show a narrowing size range and a decline in the largest lith diameters over this interval. Our results suggest no major changes in plankton calcite production during the high pCO2 Pliocene or during the transition into an icehouse world.
13
Davis, C. V., M. P. S. Badger, P. R. Bown, and D. N. Schmidt. "Calcification response to climate change in the Pliocene?" Biogeosciences Discussions 10, no. 4 (April 17, 2013): 6839–60. http://dx.doi.org/10.5194/bgd-10-6839-2013.
Повний текст джерелаАнотація:
Abstract. As a result of anthropogenic pCO2 increases future oceans are growing warmer and lower in pH and oxygen, conditions that are likely to impact planktic communities. Past intervals of elevated and changing pCO2 and temperatures can offer a glimpse into the response of marine calcifying plankton to changes in surface oceans under conditions similar to those projected for the future. Here we present new records of planktic foraminiferal and coccolith calcification from Deep Sea Drilling Project Site 607 (mid North Atlantic) and Ocean Drilling Program Site 999 (Caribbean Sea) from the Pliocene, the last time that pCO2 was similar to today, and extending through a global cooling event into the Intensification of Northern Hemisphere Glaciation (3.3 to 2.6 million years ago). Test weights of both surface-dwelling foraminifera Globigerina bulloides and thermocline-dwelling foraminifera Globorotalia puncticulata vary, with a potential link to regional temperature variation in the North Atlantic, whereas in the tropics Globigerinoides ruber test weight remains stable. In contrast, reticulofenestrid coccoliths show a narrowing size range and a decline in the largest lith diameters over this interval. Our results suggest no major changes in plankton calcification during the high pCO2 Pliocene or during the transition into an icehouse world.
14
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.
Повний текст джерелаАнотація:
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.
15
Davis, Catherine V., Tessa M. Hill, Ann D. Russell, Brian Gaylord, and Jaime Jahncke. "Seasonality in planktic foraminifera of the central California coastal upwelling region." Biogeosciences 13, no. 18 (September 16, 2016): 5139–50. http://dx.doi.org/10.5194/bg-13-5139-2016.
Повний текст джерелаАнотація:
Abstract. The close association between planktic foraminiferal assemblages and local hydrography make foraminifera invaluable proxies for environmental conditions. Modern foraminiferal seasonality is important for interpreting fossil distributions and shell geochemistry as paleoclimate proxies. Understanding this seasonality in an active upwelling area is also critical for anticipating which species may be vulnerable to future changes in upwelling intensity and ocean acidification. Two years (2012–2014) of plankton tows, along with conductivity–temperature–depth profiles and carbonate chemistry measurements taken along the north-central California shelf, offer new insights into the seasonal dynamics of planktic foraminifera in a seasonal coastal upwelling regime. This study finds an upwelling affinity for Neogloboquadrina pachyderma as well as a seasonal and upwelling associated alternation between dominance of N. pachyderma and Neogloboquadrina incompta, consistent with previous observations. Globigerina bulloides, however, shows a strong affinity for non-upwelled waters, in contrast to findings in Southern California where the species is often associated with upwelling. We also find an apparent lunar periodicity in the abundances of all species and document the presence of foraminifera even at very low saturation states of calcite.
16
Laamanen, Maria J., Muriel F. Gugger, Jaana M. Lehtimäki, Kaisa Haukka, and Kaarina Sivonen. "Diversity of Toxic and Nontoxic Nodularia Isolates (Cyanobacteria) and Filaments from the Baltic Sea." Applied and Environmental Microbiology 67, no. 10 (October 1, 2001): 4638–47. http://dx.doi.org/10.1128/aem.67.10.4638-4647.2001.
Повний текст джерелаАнотація:
ABSTRACT Cyanobacteria of the genus Nodularia form toxic blooms in brackish waters worldwide. In addition,Nodularia spp. are found in benthic, periphytic, and soil habitats. The majority of the planktic isolates produce a pentapeptide hepatotoxin nodularin. We examined the morphologic, toxicologic, and molecular characters of 18 nodularin-producing and nontoxic Nodularia strains to find appropriate markers for distinguishing the toxic strains from the nontoxic ones in field samples. After classical taxonomy, the examined strains were identified as Nodularia sp., Nodularia spumigena,N. baltica, N. harveyana, and N. sphaerocarpa. Morphologic characters were ambiguous in terms of distinguishing between the toxic and the nontoxic strains. DNA sequences from the short 16S-23S rRNA internally transcribed spacer (ITS1-S) and from the phycocyanin operon intergenic spacer and its flanking regions (PC-IGS) were different for the toxic and the nontoxic strains. Phylogenetic analysis of the ITS1-S and PC-IGS sequences from strains identified as N. spumigena, and N. baltica, and N. litorea indicated that the division of the planktic Nodularia into the three species is not supported by the ITS1-S and PC-IGS sequences. However, the ITS1-S and PC-IGS sequences supported the separation of strains designated N. harveyana and N. sphaerocarpa from one another and the planktic strains.HaeIII digestion of PCR amplified PC-IGS regions of all examined 186 Nodularia filaments collected from the Baltic Sea produced a digestion pattern similar to that found in toxic isolates. Our results suggest that only one plankticNodularia species is present in the Baltic Sea plankton and that it is nodularin producing.
17
Georgescu, Marius Dan. "Upper Cretaceous planktic foraminiferal biostratigraphy." Studia Universitatis Babes-Bolyai, Geologia 61, no. 1/2 (September 2017): 5–20. http://dx.doi.org/10.5038/1937-8602.61.1.1297.
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Hilbrecht, Heinz, and Hans R. Thierstein. "Benthic behavior of planktic foraminifera." Geology 24, no. 3 (1996): 200. http://dx.doi.org/10.1130/0091-7613(1996)024<0200:bbopf>2.3.co;2.
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Spezzaferri, Silvia, and Dorothee Spiegler. "Fossil planktic foraminifera (an overview)." Paläontologische Zeitschrift 79, no. 1 (March 2005): 149–66. http://dx.doi.org/10.1007/bf03021759.
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20
FINNEY, STANLEY C., and STEPHEN R. JACOBSON. "Flotation devices in planktic graptolites." Lethaia 18, no. 4 (October 1985): 349–59. http://dx.doi.org/10.1111/j.1502-3931.1985.tb00715.x.
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21
Albertano, Patrizia. "Planktic cyanophytes in marine environment." Giornale botanico italiano 129, no. 1 (January 1995): 405–14. http://dx.doi.org/10.1080/11263509509436154.
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22
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.
Повний текст джерелаАнотація:
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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Isnaniawardhani, Vijaya, Faizal Muhamadsyah, and Adjat Sudrajat. "FORAMINIFERA ASSEMBLAGES AS A MARKER OF MUD ERUPTION SOURCE IN CIUYAH, CINIRU – KUNINGAN, WEST JAVA." RISET Geologi dan Pertambangan 28, no. 2 (November 28, 2018): 239. http://dx.doi.org/10.14203/risetgeotam2018.v28.509.
Повний текст джерелаАнотація:
Mud eruptions that rise claystone to sandstone-size fragments, liquid, gas, and heat to the surface have been identified in Ciuyah, Ciniru District, Kuningan. Field observation and sampling were conducted on host rock as well as mud in Ciuyah. Forty-two planktic and forty-two benthic foraminiferal species were identified in rock samples; while 89.28% of them are recorded in mud samples. Foraminifera contained in claystone and sandstone of Pemali and Halang Formations reveals the age of Middle to Late Miocene. Based on their stratigraphic ranges, planktic foraminifera assemblages in mud represent four age-marker groups, there are: older than Zone N.10 / Middle Miocene (indicated by the appearance of Globorotalia archeomenardii), ranges of Zone N.11 – N.12 / Middle Miocene (marked by the appearance of Globorotalia fohsi lobata and Globorotalia praemenardii), ranges of Zone N.13–N.14 / Middle Miocene (Globorotalia siakensis and Globorotalia mayeri), and ranges of Zone N.15–N.17 / Late Miocene (Globorotalia acostaensis acostaensis and Neogloboquadrina dutertrei dutertrei). Benthic foraminifera can be grouped into outer neritic and bathyal typical assemblages. That several age-marker planktic foraminifera groups mixing and deep marine typical benthic occurrence in mud samples is produced by reworking process during turbidity sedimentation, as well as erosion and elution of base- and side-rock composed by Pemali and Halang Formations.Semburan lumpur yang membawa fragmen-fragmen berukuran batulempung hingga batupasir, cairan, gas dan panas ke permukaan telah teridentifikasi di Ciuyah, Kecamatan Ciniru, Kuningan. Observasi lapangan dan pengambilan sampel dilakukan terhadap batuan induk serta lumpur di Ciuyah dan sekitarnya. Empat puluh dua spesies foraminifera planktik dan empat puluh dua spesies bentik teridentifikasi dalam sampel batuan; dengan 89,28% di antaranya terekam dalam sampel lumpur. Foraminifera yang terkandung dalam batulempung dan batupasir Formasi Pemali dan Halang menunjukkan umur Miosen Tengah hingga Akhir. Berdasarkan rentang stratigrafinya, kumpulan foraminifera planktik dalam lumpur menunjukkan empat kelompok penanda umur, yaitu: lebih tua dari Zona N.10 / Miosen Tengah (ditunjukkan oleh kehadiran Globorotalia archeomenardii), rentang Zona N.11 - N.12 / Miosen Tengah (ditandai oleh kehadiran Globorotalia fohsi lobata dan Globorotalia praemenardii), rentang Zona N.13 -N.14 / Miosen Tengah (Globorotalia siakensis dan Globorotalia mayeri), dan rentang Zona N.15 - N.17 / Miosen Akhir (Globorotalia acostaensis acostaensis dan Neogloboquadrina dutertrei dutertrei). Foraminifera bentik dapat dikelompokkan dalam kumpulan neritik luar dan batial. Beberapa kelompok penanda umur foraminifera planktik dan kehadiran bentik laut dalam pada lumpur dihasilkan oleh pengerjaan ulang selama sedimentasi turbidit, serta erosi dan elusi batuan dasar dan batuan samping yang tersusun oleh Formasi Pemali dan Halang.
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Dong, Shuaishuai, Yanli Lei, Hongsheng Bi, Kuidong Xu, Tiegang Li, and Zhimin Jian. "Biological Response of Planktic Foraminifera to Decline in Seawater pH." Biology 11, no. 1 (January 9, 2022): 98. http://dx.doi.org/10.3390/biology11010098.
Повний текст джерелаАнотація:
Understanding the way in which a decline in ocean pH can affect calcareous organisms could enhance our ability to predict the impacts of the potential decline in seawater pH on marine ecosystems, and could help to reconstruct the paleoceanographic events over a geological time scale. Planktic foraminifera are among the most important biological proxies for these studies; however, the existing research on planktic foraminifera is almost exclusively based on their geochemical indices, without the inclusion of information on their biological development. Through a series of on-board experiments in the western tropical Pacific (134°33′54″ E, 12°32′47″ N), the present study showed that the symbiont-bearing calcifier Trilobatus sacculifer—a planktic foraminifer—responded rapidly to a decline in seawater pH, including losing symbionts, bleaching, etc. Several indices were established to quantify the relationships between these biological parameters and seawater pH, which could be used to reconstruct the paleoceanographic seawater pH. We further postulated that the loss of symbionts in planktic foraminifera acts as an adaptive response to the stress of low pH. Our results indicate that an ongoing decline in seawater pH may hinder the growth and calcification of planktic foraminifera by altering their biological processes. A reduction in carbonate deposition and predation could have profound effects on the carbon cycle and energy flow in the marine food web.
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Trommer, G., M. Siccha, E. J. Rohling, K. Grant, M. T. J. van der Meer, S. Schouten, U. Baranowski, and M. Kucera. "Sensitivity of Red Sea circulation to sea level and insolation forcing during the last interglacial." Climate of the Past 7, no. 3 (August 30, 2011): 941–55. http://dx.doi.org/10.5194/cp-7-941-2011.
Повний текст джерелаАнотація:
Abstract. This study investigates the response of Red Sea circulation to sea level and insolation changes during termination II and across the last interglacial, in comparison with termination I and the Holocene. Sediment cores from the central and northern part of the Red Sea were investigated by micropaleontological and geochemical proxies. The recovery of the planktic foraminiferal fauna following high salinities during marine isotopic stage (MIS) 6 took place at similar sea-level stand (~50 m below present day), and with a similar species succession, as during termination I. This indicates a consistent sensitivity of the basin oceanography and the plankton ecology to sea-level forcing. Based on planktic foraminifera, we find that increased water exchange with the Gulf of Aden especially occurred during the sea-level highstand of interglacial MIS 5e. From MIS 6 to the peak of MIS 5e, northern Red Sea sea surface temperature (SST) increased from 21 °C to 25 °C, with about 3 °C of this increase taking place during termination II. Changes in planktic foraminiferal assemblages indicate that the development of the Red Sea oceanography during MIS 5 was strongly determined by insolation and monsoon strength. The SW Monsoon summer circulation mode was enhanced during the termination, causing low productivity in northern central Red Sea core KL9, marked by high abundance of G. sacculifer, which – as in the Holocene – followed summer insolation. Core KL11 records the northern tip of the intruding intermediate water layer from the Gulf of Aden and its planktic foraminifera fauna shows evidence for elevated productivity during the sea-level highstand in the southern central Red Sea. By the time of MIS 5 sea-level regression, elevated organic biomarker BIT values suggest denudation of soil organic matter into the Red Sea and high abundances of G. glutinata, and high reconstructed chlorophyll-a values, indicate an intensified NE Monsoon winter circulation mode. Our results imply that the amplitude of insolation fluctuations, and the resulting monsoon strength, strongly influence the Red Sea oceanography during sea-level highstands by regulating the intensity of water exchange with the Gulf of Aden. These processes are responsible for the observation that MIS 5e/d is characterized by higher primary productivity than the Holocene.
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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.
Повний текст джерелаАнотація:
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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Broecker, Wallace S., Susan Trumbore, Georges Bonani, Willy Wölfli, and Millie Klas. "Anomalous AMS Radiocarbon Ages for Foraminifera from High-Deposition-Rate Ocean Sediments." Radiocarbon 31, no. 2 (1989): 157–62. http://dx.doi.org/10.1017/s0033822200044817.
Повний текст джерелаАнотація:
Radiocarbon ages on handpicked foraminifera from deep-sea cores are revealing that areas of rapid sediment accumulation are in some cases subject to hiatuses, reworking and perhaps secondary calcite deposition. We present here an extreme example of the impacts of such disturbances. The message is that if precise chronologies or meaningful benthic planktic age differences are to be obtained, then it is essential to document the reliability of radiocarbon ages by making both comparisons between coexisting species of planktonic foraminifera and detailed down-core sequences of measurements.
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Birch, Heather, Daniela N. Schmidt, Helen K. Coxall, Dick Kroon, and Andy Ridgwell. "Ecosystem function after the K/Pg extinction: decoupling of marine carbon pump and diversity." Proceedings of the Royal Society B: Biological Sciences 288, no. 1953 (June 23, 2021): 20210863. http://dx.doi.org/10.1098/rspb.2021.0863.
Повний текст джерелаАнотація:
The ocean biological pump is the mechanism by which carbon and nutrients are transported to depth. As such, the biological pump is critical in the partitioning of carbon dioxide between the ocean and atmosphere, and the rate at which that carbon can be sequestered through burial in marine sediments. How the structure and function of planktic ecosystems in the ocean govern the strength and efficiency of the biological pump and its resilience to disruption are poorly understood. The aftermath of the impact at the Cretaceous/Palaeogene (K/Pg) boundary provides an ideal opportunity to address these questions as both the biological pump and marine plankton size and diversity were fundamentally disrupted. The excellent fossil record of planktic foraminifera as indicators of pelagic-biotic recovery combined with carbon isotope records tracing biological pump behaviour, show that the recovery of ecological traits (diversity, size and photosymbiosis) occurred much later (approx. 4.3 Ma) than biological pump recovery (approx. 1.8 Ma). We interpret this decoupling of diversity and the biological pump as an indication that ecosystem function had sufficiently recovered to drive an effective biological pump, at least regionally in the South Atlantic.
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Fatima, Asma, Ghulam Abbas, and Robert Kasprzak. "Assessment of Hydrobiological and Soil Characteristics of Non-Fertilized, Earthen Fish Ponds in Sindh (Pakistan), Supplied with Seawater from Tidal Creeks." Water 14, no. 13 (July 2, 2022): 2115. http://dx.doi.org/10.3390/w14132115.
Повний текст джерелаАнотація:
In this study, the suitability of four earthen, seawater ponds located in the Thatta district of Sindh province (Pakistan) was evaluated for the purpose of semi-intensive mariculture, which remains to be a severely underdeveloped branch of the agricultural industry of this populous Asian country. Initial pond soil probes were promising, as they showed a high clay and silt content. Monthly water samples were obtained in the year 2019 (from January to December), which allowed for the monitoring of water parameters, as well as the identification and relative quantification of planktic populations. As a result, the monthly variations of basic water parameters were found within optimal ranges for planktic growth (water temperature, salinity, pH, transparency, and dissolved oxygen). Bacillariophyta was the largest phytoplanktic group, with the most dominant species being Sundstroemia setigera, followed by the cyanobacteria Oscillatoria limosa. Copepoda was the most numerous group of identified zooplankton, followed by tintinnids and foraminiferans. Total suspended solids (TSS) calculations indicated up to nine-fold month-to-month reductions of planktic biomass, observed in the form of diminishing Bacillariophyta (December) and Copepoda (June and December). In conclusion, the studied ponds appear to be suitable for semi-intensive mariculture activity due to the abundance of diverse planktic forms (mainly Copepoda—preferable natural food for commercially important fish species), which was achieved even without the use of fertilizers. However, significant drops of planktic biomass may still occur, which implies the need for regular water monitoring procedures, which would in turn allow fish producers to implement periodical adjustments to the administered feeding rates with artificial diets.
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Xia, Liling, Yuelong Zhu, and Zhenhua Zhao. "Understanding the Ecological Response of Planktic and Benthic Epipelic Algae to Environmental Factors in an Urban Rivers System." Water 12, no. 5 (May 6, 2020): 1311. http://dx.doi.org/10.3390/w12051311.
Повний текст джерелаАнотація:
Many studies have been concentrated on the distribution of algae in lakes, rivers, and seas, however, few studies have been concerned about their distribution and relation with polluted urban rivers. In this study, the spatio-temporal variation characteristics of water quality and algae community in Nanjing city were investigated with microscopic examination for one year. Results showed that the water pollution in this area was mainly related to high concentration of nitrogen (NH3-N and TN (Total nitrogen). There was a total of 77 species of algae in the studied rivers from June 2016 to May 2017, among which 73 species of planktic algae and 34 species of epipelic algae, in which the abundance and biomass of the latter were 1925 and 904 times that of the former, respectively. The two kinds of algae had different change tendencies which were related to seasons. For planktic algae, the abundance and biomass decreased in this season sequence: summer, spring, autumn, and winter. For epipelic algae, the abundance and biomass were relatively higher in winter. The dominant community of planktic algae was Chlorophyta-Bacillariophyceae-Cyanobacteria type, while that of epipelic algae was Bacillariophyceae—Cyanobacteria type. Most of the present algae were bi-trophic species, and were tightly related to the pollution characteristics of the rivers. The key environmental factors for planktic algae are T, TN, and TP, and those for Epipelic algae are N:P and TN. The relation between the community composition of planktic and epipelic algae and environmental parameters are highly complex, and it is worth carrying out further study to clarify their interaction mechanism.
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Davis, Catherine V., Jennifer S. Fehrenbacher, Claudia Benitez-Nelson, and Robert C. Thunell. "Trace Element Heterogeneity Across Individual Planktic Foraminifera from the Modern Cariaco Basin." Journal of Foraminiferal Research 50, no. 2 (April 1, 2020): 204–18. http://dx.doi.org/10.2113/gsjfr.50.2.204.
Повний текст джерелаАнотація:
ABSTRACT The trace element composition of planktic foraminifera shells is influenced by both environmental and biological factors (‘vital effects’). As trace elements in individual foraminifera shells are increasingly used as paleoceanographic tools, understanding how trace element ratios vary between individuals, among species, and in response to high frequency environmental variability is of critical importance. Here, we present a three-year plankton tow record (2010–2012) of individual shell trace element (Mg, Sr, Ba, and Mn) to Ca ratios in the planktic species Globigerina ruber (pink), Orbulina universa, and Globorotalia menardii collected throughout the upper 100 m of Cariaco Basin. Plankton tows were paired with in situ measurements of water column chemistry and hydrography. The Mg/Ca ratio reflects different calcification temperatures in all three species when calculated using species-specific temperature relationships from single-species averages of Mg/Ca. However, individual shell Mg/Ca often results in unrealistic temperate estimates. The Sr/Ca ratios are relatively constant among the four species. Ratios of Mn/Ca and Ba/Ca are highest in G. menardii and are not reflective of elemental concentrations in open waters. The Mn/Ca ratio is elevated in all species during upwelling conditions, and a similar trend is demonstrated in Neogloboquadrina incompta shells from the California margin collected during upwelling periods. Together this suggests that elevated shell Mn/Ca may act as a tracer for upwelling of deeper water masses. Our results emphasize the large degree of trace element variability present among and within species living within a limited depth habitat and the roles of biology, calcification environment, and physical mixing in mediating how trace element geochemistry reflects environmental variability in the surface ocean.
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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.
Повний текст джерелаАнотація:
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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Ridgwell, A., I. Zondervan, J. C. Hargreaves, J. Bijma, and T. M. Lenton. "Significant long-term increase of fossil fuel CO<sub>2</sub> uptake from reduced marine calcification." Biogeosciences Discussions 3, no. 6 (November 13, 2006): 1763–80. http://dx.doi.org/10.5194/bgd-3-1763-2006.
Повний текст джерелаАнотація:
Abstract. Analysis of available plankton manipulation experiments demonstrates a previously unrecognized wide range of sensitivities of biogenic calcification to simulated anthropogenic acidification of the ocean, with the "lab rat" of planktic calcifiers, Emiliania huxleyi not representative of calcification generally. We assess the implications of the experimental uncertainty in plankton calcification response by creating an ensemble of realizations of an Earth system model that encapsulates a comparable range of uncertainty in calcification response. We predict a substantial future reduction in marine carbonate production, with ocean CO2 sequestration across the model ensemble enhanced by between 62 and 199 PgC by the year 3000, equivalent to a reduction in the atmospheric fossil fuel CO2 burden at that time of up to 13%. Concurrent changes in ocean circulation and surface temperatures contribute about one third to the overall importance of reduced plankton calcification.
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Kendall, Sophie, Felix Gradstein, Christopher Jones, Oliver T. Lord, and Daniela N. Schmidt. "Ontogenetic disparity in early planktic foraminifers." Journal of Micropalaeontology 39, no. 1 (February 12, 2020): 27–39. http://dx.doi.org/10.5194/jm-39-27-2020.
Повний текст джерелаАнотація:
Abstract. Changes in morphology during ontogeny can have profound impacts on the physiology and biology of a species. Studies of ontogenetic disparity through time are rare because of the lack of preservation of developmental stages in the fossil record. As they grow by incremental chamber accretion and retain evidence of growth in their shell, planktic foraminifera are an ideal group for the study ontogenetic disparity through the evolution of a higher taxon. Here, we quantify different developmental stages in Jurassic foraminifers and infer the evolutionary implications of the shape of these earliest representatives of the group. Using a Zeiss Xradia micro-CT scanner, the development of Globuligerina bathoniana and Globuligerina oxfordiana from the Bathonian sediments of Gnaszyn, Poland, and Globuligerina balakhmatovae and Globuligerina tojeiraensis from the Kimmeridgian Tojeira Formation of Portugal was reconstructed. Disparity is low through the early evolution of planktic foraminifers. The number of chambers and range in surface area per unit volume are lower than in modern specimens. We interpret this morphology as an indication of opportunistic behaviour. The low morphological plasticity during the juvenile stage suggests that strong constraints on the juveniles, described in the modern ocean, were already acting on Jurassic specimens. The high surface area per unit volume in these developmental stages points towards the need to satisfy a higher metabolic demand than in the adult specimens. We are interpreting the lower chamber numbers as indicative of short life cycles and potentially rapid reproduction, both of which may have allowed these species to exploit the nutrient-rich waters of the Jurassic Tethys Ocean.
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Fraass, Andrew J., D. Clay Kelly, and Shanan E. Peters. "Macroevolutionary History of the Planktic Foraminifera." Annual Review of Earth and Planetary Sciences 43, no. 1 (May 30, 2015): 139–66. http://dx.doi.org/10.1146/annurev-earth-060614-105059.
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Darling, K. F., D. Kroon, C. M. Wade, and A. J. Leigh Brown. "Molecular phylogeny of the planktic foraminifera." Journal of Foraminiferal Research 26, no. 4 (October 1, 1996): 324–30. http://dx.doi.org/10.2113/gsjfr.26.4.324.
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Norris, R. D., R. M. Corfield, and J. E. Cartlidge. "Evolutionary ecology ofGloborotalia (Globoconella) (planktic foraminifera)." Marine Micropaleontology 23, no. 2 (February 1994): 121–45. http://dx.doi.org/10.1016/0377-8398(94)90004-3.
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D’Onofrio, Roberta, Valeria Luciani, Gerald R. Dickens, Bridget S. Wade, and Sandra Kirtland Turner. "Demise of the Planktic Foraminifer Genus Morozovella during the Early Eocene Climatic Optimum: New Records from ODP Site 1258 (Demerara Rise, Western Equatorial Atlantic) and Site 1263 (Walvis Ridge, South Atlantic)." Geosciences 10, no. 3 (February 27, 2020): 88. http://dx.doi.org/10.3390/geosciences10030088.
Повний текст джерелаАнотація:
Here we present relative abundances of planktic foraminifera that span the Early Eocene Climatic Optimum (EECO) at Ocean Drilling Program (ODP) Site 1258 in the western equatorial Atlantic. The EECO (~53.3−49.1 Ma) represents peak Cenozoic warmth, probably related to high atmospheric CO2, and when planktic foraminifera, a dominant component of marine sediment, exhibit a major biotic response. Consistent with previous work, the relative abundance of the genus Morozovella, which dominated early Paleogene tropical-subtropical assemblages, markedly and permanently declined from a mean percentage of ~32% to less than ~7% at the beginning of the EECO. The distinct decrease in Morozovella abundance occurred at Site 1258 within ~20 kyr before a negative excursion in δ13C records known as the J event and which defines the beginning of EECO. Moreover, all morozovellid species except M. aragonensis dropped in abundance permanently at Site 1258, and this is related to a reduction in test-size. Comparing our data with that from other locations, the remarkable switch in planktonic foraminifera assemblages appears to have begun first with unfavourable environmental conditions near the Equator and then extended to higher latitudes. Several potential stressors may explain observations, including some combination of algal photosymbiont inhibition (bleaching), a sustained increase in temperature, or an extended decrease in pH.
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Davis, Catherine V., Caitlin M. Livsey, Hannah M. Palmer, Pincelli M. Hull, Ellen Thomas, Tessa M. Hill, and Claudia R. Benitez-Nelson. "Extensive morphological variability in asexually produced planktic foraminifera." Science Advances 6, no. 28 (July 2020): eabb8930. http://dx.doi.org/10.1126/sciadv.abb8930.
Повний текст джерелаАнотація:
Marine protists are integral to the structure and function of pelagic ecosystems and marine carbon cycling, with rhizarian biomass alone accounting for more than half of all mesozooplankton in the oligotrophic oceans. Yet, understanding how their environment shapes diversity within species and across taxa is limited by a paucity of observations of heritability and life history. Here, we present observations of asexual reproduction, morphologic plasticity, and ontogeny in the planktic foraminifer Neogloboquadrina pachyderma in laboratory culture. Our results demonstrate that planktic foraminifera reproduce both sexually and asexually and demonstrate extensive phenotypic plasticity in response to nonheritable factors. These two processes fundamentally explain the rapid spatial and temporal response of even imperceptibly low populations of planktic foraminifera to optimal conditions and the diversity and ubiquity of these species across the range of environmental conditions that occur in the ocean.
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Mallo, Miguel, Patrizia Ziveri, P. Graham Mortyn, Ralf Schiebel, and Michael Grelaud. "Low planktic foraminiferal diversity and abundance observed in a spring 2013 west–east Mediterranean Sea plankton tow transect." Biogeosciences 14, no. 9 (May 4, 2017): 2245–66. http://dx.doi.org/10.5194/bg-14-2245-2017.
Повний текст джерелаАнотація:
Abstract. Planktic foraminifera were collected with 150 µm BONGO nets from the upper 200 m water depth at 20 stations across the Mediterranean Sea between 2 May and 2 June 2013. The main aim is to characterize the species distribution and test the covariance between foraminiferal area density (ρA) and seawater carbonate chemistry in a biogeochemical gradient including ultraoligotrophic conditions. Average foraminifera abundances are 1.42 ± 1.43 ind. 10 m−3 (ranging from 0.11 to 5.20 ind. 10 m−3), including 12 morphospecies. Large differences in species assemblages and total abundances are observed between the different Mediterranean sub-basins, with an overall dominance of spinose, symbiont-bearing species indicating oligotrophic conditions. The highest values in absolute abundance are found in the Strait of Gibraltar and the Alboran Sea. The western basin is dominated by Globorotalia inflata and Globigerina bulloides at slightly lower standing stocks than in the eastern basin. In contrast, the planktic foraminiferal assemblage in the warmer, saltier, and more nutrient-limited eastern basin is dominated by Globigerinoides ruber (white). These new results, when combined with previous findings, suggest that temperature-induced surface water stratification and food availability are the main factors controlling foraminiferal distribution. In the oligotrophic and highly alkaline and supersaturated with respect to calcite and aragonite Mediterranean surface water, standing stocks and ρA of G. ruber (white) and G. bulloides are affected by both food availability and seawater carbonate chemistry. Rapid warming increased surface ocean stratification impacting food availability and changes in trophic conditions could be the causes of reduced foraminiferal abundance, diversity, and species-specific changes in planktic foraminiferal calcification.
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Komárek, Jiří, and Patrizia Albertano. "Cell structure of a planktic cyanoprokaryote, Tychonema bourrellyi." Algological Studies/Archiv für Hydrobiologie, Supplement Volumes 75 (October 27, 1995): 157–66. http://dx.doi.org/10.1127/algol_stud/75/1995/157.
Повний текст джерела
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D'Hondt, Steven, James C. Zachos, and Gretchen Schultz. "Stable isotopic signals and photosymbiosis in Late Paleocene planktic foraminifera." Paleobiology 20, no. 3 (1994): 391–406. http://dx.doi.org/10.1017/s0094837300012847.
Повний текст джерелаАнотація:
Late Paleocene planktic foraminifera exhibit strong positive correlations between carbon isotopic values and test mass, but negative correlations between oxygen isotopic values and test mass. Based on analogy with modern taxa, these trends are probably ecotypic and may or may not apply to an ontogenetic series. Among Acarinina and Morozovella species, the magnitude and direction of these trends resemble those of modern planktic foraminifera with dinoflagellate photosymbionts. This is consistent with current models of photosymbiosis and calcification in planktic foraminifera and suggests that Acarinina and Morozovella relied heavily on photosymbionts for nutrition.Acarinina and Morozovella species resemble modern, strongly photosymbiotic taxa in their association with low and mid latitude nearsurface water masses. However, their test morphologies differ greatly from those of extant taxa that bear obligate photosymbionts. Earliest Paleocene taxa that exhibit a similar paleohabitat association and similar size-related isotopic trends are characterized by still different test morphologies. These comparisons suggest that (1) throughout geologic time, strong reliance on photosymbiont activity has been closely linked to habitat, but not to test morphology; (2) photosymbiosis has been a common and convergently evolved strategy of planktic foraminifera over geologic time, and (3) modern relationships between planktic foraminiferal test morphology and photosymbiont dependence are largely an artifact of geologically recent phylogenetic relationships and shared ecologic strategies.Intersite comparison suggests that the stable isotopic signals of narrowly constrained size fractions of a late Paleocene Acarinina or Morozovella species can be used to reconstruct the magnitude and direction of relative variation in equilibrium stable isotopic values throughout its geographic and temporal range. This is supported by analogy with extant photosymbiotic taxa. However, since photosynthetic depletion of 12C leaves 13C-enriched HCO3-for calcification, the carbon isotopic values of Acarinina and Morozovella tests may have been consistently greater than paleoseawater values. Failure to account for this effect could lead to overestimation of late Paleocene marine productivity.
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Arenillas, Ignacio, José A. Arz, Fariza Metsana-Oussaid, Vicente Gilabert, and Djelloul Belhai. "Hypothesis testing on the planktic foraminiferal survival model after the KPB mass extinction: evidence from Tunisia and Algeria." Fossil Record 25, no. 1 (February 7, 2022): 43–63. http://dx.doi.org/10.3897/fr.25.79958.
Повний текст джерелаАнотація:
A historical review of the extinction, survival, and evolutionary models of planktic foraminifera proposed for the Cretaceous/Paleogene boundary (KPB) mass extinction event sometimes leaves the impression that there is still no conclusive evidence to support any single one of them. Two main models have been put forward: i) catastrophic mass extinction, almost total for some authors, compatible with the geologically instantaneous paleoenvironmental effects of a large meteorite impact (Chicxulub impact, Mexico); and ii) gradual mass extinction, compatible with the paleoenvironmental effects of massive, long-lasting volcanism (Deccan Traps, India). Over the years, a lot of evidence has been proposed supporting one hypothesis or the other, highlighting isotopic (δ18O, δ13C, 87Sr/86Sr) as well as taphonomic, biostratigraphic, quantitative (relative and/or absolute abundance), phylogenetic, and even teratological. We review previous planktic foraminiferal and stable isotope studies, and provide new quantitative and statistical tests from two pelagic sections: the El Kef section (Tunisia), recognized as the most continuous and expanded lowermost Danian section worldwide, and the Sidi Ziane section (Algeria), affected by relevant hiatus in the lower Danian. The results indicate that all the latest Maastrichtian planktic foraminiferal species except those of Guembelitria went extinct exactly at the KPB, supporting the hypothesis of an almost total extinction. In the light of this new evidence, we maintain that the Maastrichtian planktic foraminiferal specimens found worldwide in lower Danian samples could be the result of similar reworking and vertical mixing processes to those at El Kef and Sidi Ziane.
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Luciani, V., J. Backman, E. Fornaciari, L. Giusberti, C. Agnini та R. D'Onofrio. "Massive and permanent decline of symbiont bearing morozovellids and δ<sup>13</sup>C perturbations across the Early Eocene Climatic Optimum at the Possagno section (Southern Alps of northeastern Italy)". Climate of the Past Discussions 11, № 2 (16 березня 2015): 671–712. http://dx.doi.org/10.5194/cpd-11-671-2015.
Повний текст джерелаАнотація:
Abstract. The Early Eocene Climatic Optimum (EECO) records the highest prolonged global temperatures over the past 70 Ma. Understanding the causes and timing of Eocene climate change remains a major challenge in Cenozoic paleoceanography, which includes the biotic response to climate variability and the changes among planktic foraminiferal assemblages across the EECO. The symbiont bearing and shallow dwelling genera Morozovella and Acarinina were important calcifiers in the tropical-subtropical early Paleogene oceans but almost completely disappeared at about 38 Ma, near the Bartonian/Priabonian boundary. We show here that morozovellids record a first critical step across the EECO through a major permanent decline in relative abundance from the Tethyan Possagno section and ODP Site 1051 in the western subtropical North Atlantic. Possible causes may include increased eutrophication, weak water column stratification, changes in ocean chemistry, loss of symbiosis and possible complex interaction with other microfossil groups. Relative abundances of planktic foraminiferal taxa at Possagno parallel negative shifts in both δ13C and δ18O of bulk sediment from Chron C24r to basal Chron C20r. The post-EECO stable isotopic excursions towards lighter values are of modest intensity. Significant though ephemeral modifications in the planktic foraminiferal communities occur during these minor isotopic excursions. These modifications are marked by pronounced increases in relative abundance of acarininids, in a manner similar to their behaviour during pre-EECO hyperthermals in the Tethyan settings, which suggest a pronounced biotic sensitivity to climate change of planktic foraminifera even during the post-EECO interval.
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Hancock, Haidi J. L., George C. Chaproniere, Gerald R. Dickens, and Robert A. Henderson. "Early Palaeogene planktic foraminiferal and carbon isotope stratigraphy, Hole 762C, Exmouth Plateau, northwest Australian margin." Journal of Micropalaeontology 21, no. 1 (May 1, 2002): 29–42. http://dx.doi.org/10.1144/jm.21.1.29.
Повний текст джерелаАнотація:
Abstract. Although the northwest margin of Australia is an important region for petroleum exploration and palaeoceanographic investigations, its Palaeogene stratigraphy is poorly documented, especially in terms of a foraminiferal biozonation. Early Palaeogene cores from 502.96 to 307.80 m below sea floor at Ocean Drilling Program Site 762 on the Exmouth Plateau were examined in this study for their planktic foraminiferal assemblages and the carbon isotopic compositions of Subbotina spp. Planktic foraminifera are generally well preserved and belong to 74 species and 17 genera. In spite of a mid-latitudinal palaeolatitude (c. 40°S) the sequence, deposited between the early Paleocene and Middle Eocene, contains all planktic foraminiferal Zones P1c through P10 of the current global scheme for tropical locations, except for Subzone P4b. Most zones are well defined by the datums of primary marker species except P3a and P9, which have boundaries that probably occur in core gaps, and the P9 zonal boundaries are defined by secondary marker species. Overall, variations in δ13C based on sequential samples of Subbotina are similar in pattern and magnitude to global summary isotope curves spanning the early Palaeogene. However, the prominent δ13C excursion that characterizes the Palaeocene/Eocene transition is mostly missing and appears to lie in a core gap. The planktic foraminiferal zonation, linked with that based on nannofossils, a recalibrated magnetostratigraphy and carbon isotope records, provides a robust temporal framework for the Early Palaeogene of the northwest margin of Australia.
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Okazaki, Y., T. Sagawa, H. Asahi, K. Horikawa, and J. Onodera. "Ventilation changes in the western North Pacific since the last glacial period." Climate of the Past 8, no. 1 (January 3, 2012): 17–24. http://dx.doi.org/10.5194/cp-8-17-2012.
Повний текст джерелаАнотація:
Abstract. We reconstructed the ventilation record of deep water at 2100 m depth in the mid-latitude western North Pacific over the past 25 kyr from radiocarbon measurements of coexisting planktic and benthic foraminiferal shells in sediment with a high sedimentation rate. The 14C data on fragile and robust planktic foraminiferal shells were concordant with each other, ensuring high quality of the reconstructed ventilation record. The radiocarbon activity changes were consistent with the atmospheric record, suggesting that no massive mixing of old carbon from the abyssal reservoir occurred throughout the glacial to deglacial periods.
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Okazaki, Y., T. Sagawa, H. Asahi, K. Horikawa, and J. Onodera. "Ventilation changes in the western North Pacific since the last glacial period." Climate of the Past Discussions 7, no. 4 (August 18, 2011): 2719–39. http://dx.doi.org/10.5194/cpd-7-2719-2011.
Повний текст джерелаАнотація:
Abstract. We reconstructed the ventilation record of deep water at 2100 m depth in the mid-latitude western North Pacific over the past 25 kyr from radiocarbon measurements of coexisting planktic and benthic foraminiferal shells in sediment with a high sedimentation rate. The 14C data on fragile and robust planktic foraminiferal shells were concordant with each other, ensuring high quality of the reconstructed ventilation record. The radiocarbon activity changes were consistent with the atmospheric record, suggesting that no massive mixing of old carbon from the abyssal reservoir occurred throughout the glacial to deglacial periods.
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Flower, B. P., D. W. Hastings, and N. J. Randle. "Paired AMS 14C Dates on Planktic Foraminifera from a Gulf of Mexico Sediment Core: An Assessment of Stratigraphic Continuity." Radiocarbon 53, no. 2 (2011): 337–44. http://dx.doi.org/10.1017/s0033822200056599.
Повний текст джерелаАнотація:
A series of recent papers has called for multiple radiocarbon dates on planktic foraminifera to assess stratigraphic continuity in deep-sea sediment cores. This recommendation comes from observations of anomalous 14C dates in planktic foraminifera from the same stratigraphic level. Potential reasons include bioturbation, downslope transport, secondary calcification, carbonate dissolution, and differential preservation. In this study, paired 14C dates on dissolution-susceptible Globigerinoides ruber and dissolution-resistant Neogloboquadrina dutertrei are used to evaluate a Gulf of Mexico sediment core. Fourteen of 15 pairs (between 8815 and 12,995 uncorrected 14C yr BP) yield concordant uncorrected 14C ages (mean difference −2 ± 75 yr), attesting to continuous deposition at high accumulation rates (>35 cm/kyr). For 1 pair, N. dutertrei is nearly 1000 yr younger, which is difficult to explain by any combination of dissolution and bioturbation or downslope transport, given the excellent carbonate preservation and persistent laminations. The concordant ages underscore the utility of paired 14C dates in planktic foraminifera as a means of assessing stratigraphic continuity in deep-sea sediment sequences.
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Jentzen, Anna, Joachim Schönfeld, and Ralf Schiebel. "Assessment of the Effect of Increasing Temperature On the Ecology and Assemblage Structure of Modern Planktic Foraminifers in the Caribbean and Surrounding Seas." Journal of Foraminiferal Research 48, no. 3 (July 2, 2018): 251–72. http://dx.doi.org/10.2113/gsjfr.48.3.251.
Повний текст джерелаАнотація:
Abstract Habitat patterns of subtropical and tropical planktic foraminifers in the Caribbean Sea were obtained from plankton samples collected in spring 2009 and 2013. The spatial distribution in surface waters (3.5 m water depth) and depth habitat patterns (surface to 400 m) of 33 species were compared with prevailing water-mass conditions (temperature, salinity, and chlorophyll-a concentration) and planktic foraminiferal test assemblages in surface sediments. Distribution patterns indicate a significant relationship with seawater temperature and trophic conditions. A reduction in standing stocks was observed close to the Orinoco River plume and in the Gulf of Paria, associated with high turbidity and concomitant low surface-water salinity. In contrast, a transient mesoscale patch of high chlorophyll concentration in the eastern Caribbean Sea was associated with higher standing stocks in near surface waters, including high abundances of Globigerinita glutinata and Neogloboquadrina dutertrei. Globorotalia truncatulinoides mainly lives close to the seasonal pycnocline and can be linked to winter conditions indicated by lower sea-surface temperatures (SSTs) of ∼20°C. Globigerinoides sacculifer and Globoturborotalita rubescens were associated with oligotrophic conditions in the pelagic Caribbean Sea during early spring and showed a synodic lunar reproduction cycle. The live assemblages in the water column from 2009 and 2013 were similar to those reported in earlier studies from the 1960s and 1990s and to assemblages of tests in the surface sediments. Minor differences in faunal proportions were attributed to seasonal variability and environmental differences at the local scale. An exception was the low relative abundance of Globigerinoides ruber in the Caribbean Sea in 2009 compared to surface sediment samples and plankton net samples collected in the 1960s and 1990s. Decreasing abundance of Gs. ruber white in the Caribbean Sea may be associated with increasing SSTs over past decades and changes in nutrient flux and primary production.
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Gajewska, Maria, Zofia Dubicka, and Malcolm B. Hart. "Jurassic planktic foraminifera from the Polish Basin." Journal of Micropalaeontology 40, no. 1 (January 27, 2021): 1–13. http://dx.doi.org/10.5194/jm-40-1-2021.
Повний текст джерелаАнотація:
Abstract. Jurassic (Bathonian–Oxfordian) planktic foraminifera from the epicontinental strata of the Polish Basin have been investigated. The palaeoecology, palaeobiogeography, and biostratigraphical potential of the recorded taxa are discussed. Four species are recorded: Conoglobigerina helvetojurassica (Haeusler, 1881), Globuligerina balakhmatovae (Morozova, 1961), G. bathoniana (Pazdrowa, 1969), and G. oxfordiana (Grigelis, 1958). This assemblage is probably the most diverse of those described to date from the epicontinental areas of Europe. The recorded taxa are thought to represent three different ecological morphotypes. The clear relationship between transgressive–regressive facies and the palaeobiogeography of the recorded planktic foraminifera indicates a morphotype-related depth–distribution pattern in which small, simple, globular-chambered morphotypes occupied shallow waters whereas slightly larger, more complex forms, or those with hemispherical chambers, inhabited deeper and more open-water environments.