scholarly journals Revision of 'Variable habitat depth of the planktonic foraminifera Neogloboquadrina pachyderma...' by Greco et al.

2019 ◽  
Author(s):  
Anonymous
Keyword(s):  
Planktonic Foraminifera ◽  
Habitat Depth ◽  
Neogloboquadrina Pachyderma

scholarly journals Variable habitat depth of the planktonic foraminifera <i>Neogloboquadrina pachyderma</i> in the northern high latitudes explained by sea-ice and chlorophyll concentration

2019 ◽  
Author(s):  
Mattia Greco ◽  
Lukas Jonkers ◽  
Kerstin Kretschmer ◽  
Jelle Bijma ◽  
Michal Kucera
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Mixed Layer ◽  
Planktonic Foraminifera ◽  
Sea Surface ◽  
The Arctic ◽  
Future Climate Change ◽  
Polar Regions ◽  
Habitat Depth ◽  
Neogloboquadrina Pachyderma

Abstract. Neogloboquadrina pachyderma is the dominant species in the polar regions. In the northern high latitude ocean, it makes up more than 90 % of the total planktonic foraminifera assemblages, making it the dominant pelagic calcifier and carrier of paleoceanographic proxies. To assess the reaction of this species to future climate change and to be able to interpret the paleoecological signal contained in its shells, its habitat depth must be known. Previous work showed that N. pachyderma in the northern polar regions has a highly variable depth habitat, ranging from the surface mixed layer to several hundreds of metres below the surface, and the origin of this variability remained unclear. In order to investigate the factors controlling the habitat depth of N. pachyderma, we compiled new and existing population density profiles from 104 stratified plankton tow hauls collected in the Arctic and the North Atlantic Oceans during 14 oceanographic expeditions. For each vertical profile, the Depth Habitat (DH) was calculated as the abundance-weighted mean depth of occurrence. We then tested to what degree environmental factors (mixed layer depth, sea surface temperature, sea surface salinity, Chlorophyll a concentration and sea ice concentration) and ecological factors (synchronised reproduction and daily vertical migration) can predict the observed DH variability and compared the observed DH behaviour with simulations by a numerical model predicting planktonic foraminifera distribution. Our data show that the DH of N. pachyderma varies between 25 m and 280 m (average ~ 100 m). In contrast with the model simulations, which indicate that DH is associated with the depth of chlorophyll maximum, our analysis indicates that the presence of sea-ice together with the concentration of chlorophyll at the surface have the strongest influence on the vertical habitat of this species. N. pachyderma occurs deeper when sea-ice and chlorophyll concentrations are low, suggesting a time transgressive response to the evolution of (near) surface conditions during the annual cycle. Since only surface parameters appear to affect the vertical habitat of N. pachyderma, light or light-dependant processes might influence the ecology of this species. Our results can be used to improve predictions of the response of the species to climate change and thus to refine paleoclimatic reconstructions.

CARBONATE DISSOLUTION AND ULTRASTRUCTURAL BREAKDOWN IN PLANKTONIC FORAMINIFERA IN THE SEA OF OKHOTSK

2017 ◽  
Author(s):  
Alexandra Romanova ◽  
Alexandra Romanova ◽  
Vladimir Anin ◽  
Vladimir Anin ◽  
Sergey Pletnev ◽  
...  
Keyword(s):  
Sea Of Okhotsk ◽  
Planktonic Foraminifera ◽  
Carbonate Dissolution ◽  
Calcite Dissolution ◽  
The Sea Of Okhotsk ◽  
Globigerina Bulloides ◽  
Neogloboquadrina Pachyderma ◽  
Thin Walled ◽  
Shell Fragments ◽  
Degree Of Fragmentation

80 sediment stations collected along the meridian transect across the Sea of Okhotsk were studied in order to reveal patterns of dissolution based on planktonic foraminifera. The degree of calcite dissolution intensity from planktonic foraminifera determined by different indices (degree of fragmentation, presence of susceptible to dissolution species, benthos/ plankton ratio). The highest degree of dissolution evidenced by a large number of shell fragments and corroding walls were found in sediments from the area of the Kuril Islands. The most revealing measure of probable dissolution of foraminiferal shells in the central part of the sea is a low number and lack of thin-walled species. The effects of dissolution on foraminiferal shells were studied for dominated species Neogloboquadrina pachyderma sin and Globigerina bulloides using a scanning electron microscope. The results are important for understanding processes of sedimentation, the paleo-oceanologial reconstructions and for obtaining reliable results in isotope analyzes.

scholarly journals Planktonic foraminifera genomic variations reflect paleoceanographic changes in the Arctic: evidence from sedimentary ancient DNA

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Joanna Pawłowska ◽  
Jutta E. Wollenburg ◽  
Marek Zajączkowski ◽  
Jan Pawlowski
Keyword(s):  
Ancient Dna ◽  
Sequence Data ◽  
Planktonic Foraminifera ◽  
Molecular Ecology ◽  
The Arctic ◽  
Marine Biodiversity ◽  
Neogloboquadrina Pachyderma ◽  
Rna Genes ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract Deciphering the evolution of marine plankton is typically based on the study of microfossil groups. Cryptic speciation is common in these groups, and large intragenomic variations occur in ribosomal RNA genes of many morphospecies. In this study, we correlated the distribution of ribosomal amplicon sequence variants (ASVs) with paleoceanographic changes by analyzing the high-throughput sequence data assigned to Neogloboquadrina pachyderma in a 140,000-year-old sediment core from the Arctic Ocean. The sedimentary ancient DNA demonstrated the occurrence of various N. pachyderma ASVs whose occurrence and dominance varied through time. Most remarkable was the striking appearance of ASV18, which was nearly absent in older sediments but became dominant during the last glacial maximum and continues to persist today. Although the molecular ecology of planktonic foraminifera is still poorly known, the analysis of their intragenomic variations through time has the potential to provide new insight into the evolution of marine biodiversity and may lead to the development of new and important paleoceanographic proxies.

Oceanographic implications of recent planktonic foraminifera along the southern Australian margin

1998 ◽  
Vol 49 (5) ◽  
pp. 439 ◽  
Author(s):  
Qianyu Li ◽  
Brian McGowran
Keyword(s):  
Cold Water ◽  
Saline Water ◽  
Planktonic Foraminifera ◽  
South Australia ◽  
Last Interglacial ◽  
The South ◽  
Leeuwin Current ◽  
Neogloboquadrina Pachyderma ◽  
Great Australian Bight ◽  
Subtropical Species

The distribution of planktonic foraminifera along the southern Australian margin is strongly gradational from warmer assemblages in the west to more temperate assemblages in the east. This pattern follows a decreasing temperature gradient generated by the warm Leeuwin Current which flows southward and then eastward on the southern margin. The abundances of tropical and subtropical species including Globorotalia menardii and Globigerinoides trilobus s.l. decrease rapidly after rounding the south-western corner, while the temperate index species Globorotalia inflata increases and subsequently dominates the fauna towards the east, especially on the Lincoln and Lacepede shelves of South Australia. This W–E gradation is also observed in the relict Pleistocene assemblages, indicating that the Leeuwin Current has been influential since at least the last interglacial time. The interaction between the warm and saline water from the Great Australian Bight and cold water from the south produced an assemblage in deeper parts of the Bight with abundant small species such as Globigerina falconensis, Globotur-borotalita rubescens, Neogloboquadrina pachyderma and Turborotalita quinqueloba.

CARBONATE DISSOLUTION AND ULTRASTRUCTURAL BREAKDOWN IN PLANKTONIC FORAMINIFERA IN THE SEA OF OKHOTSK

2017 ◽  
Author(s):  
Alexandra Romanova ◽  
Alexandra Romanova ◽  
Vladimir Anin ◽  
Vladimir Anin ◽  
Sergey Pletnev ◽  
...  
Keyword(s):  
Sea Of Okhotsk ◽  
Planktonic Foraminifera ◽  
Carbonate Dissolution ◽  
Calcite Dissolution ◽  
The Sea Of Okhotsk ◽  
Globigerina Bulloides ◽  
Neogloboquadrina Pachyderma ◽  
Thin Walled ◽  
Shell Fragments ◽  
Degree Of Fragmentation

80 sediment stations collected along the meridian transect across the Sea of Okhotsk were studied in order to reveal patterns of dissolution based on planktonic foraminifera. The degree of calcite dissolution intensity from planktonic foraminifera determined by different indices (degree of fragmentation, presence of susceptible to dissolution species, benthos/ plankton ratio). The highest degree of dissolution evidenced by a large number of shell fragments and corroding walls were found in sediments from the area of the Kuril Islands. The most revealing measure of probable dissolution of foraminiferal shells in the central part of the sea is a low number and lack of thin-walled species. The effects of dissolution on foraminiferal shells were studied for dominated species Neogloboquadrina pachyderma sin and Globigerina bulloides using a scanning electron microscope. The results are important for understanding processes of sedimentation, the paleo-oceanologial reconstructions and for obtaining reliable results in isotope analyzes

Foraminiferal Solubility Rankings: a Contribution To the Search For Consensus

2018 ◽  
Vol 48 (4) ◽  
pp. 301-313 ◽  
Author(s):  
Sandro M. Petró ◽  
María A. G. Pivel ◽  
João C. Coimbra
Keyword(s):  
Planktonic Foraminifera ◽  
Differential Resistance ◽  
South Atlantic ◽  
Neogloboquadrina Pachyderma ◽  
Resistant Species ◽  
Oxygen Isotopic ◽  
Orbulina Universa ◽  
Moderately Resistant ◽  
Mg Content ◽  
Isotopic Signal

Abstract Factors intrinsic to foraminiferal tests result in different degrees of susceptibility to dissolution. Differential resistance to dissolution among planktonic foraminifera has been studied in several regions, but no previous work has been reported for the western South Atlantic. The goal of this research was to develop a dissolution susceptibility ranking for planktonic foraminifera from the western South Atlantic Ocean, to compare the solubility between benthic and planktonic foraminifera, and to evaluate changes in the oxygen isotopic signal (δ18O) associated with dissolution. Two experiments were carried out by immersing tests in acetic acid or distilled water for 200 days. Our comparison revealed that tests of planktonic foraminifera were more resistant to dissolution than the benthic species tested, which has implications for use of the planktonic/benthic ratio (P/B) as a preservation proxy. Solubility of tests is directly proportional to the Mg content in the calcite structure, which varies widely across benthic taxa but is consistently low in planktonics. The δ18O increased during dissolution, probably due to the preferential dissolution of the internal chambers, making the remaining calcite progressively reflect the composition of the last chambers. Our solubility ranking for planktonic foraminifera agreed in part with rankings for foraminifera from other regions. Neogloboquadrina pachyderma and Globorotalia inflata proved to be resistant species; Globigerinella calida, Globigerinella siphonifera, Globorotalia hirsuta, Candeina nitida, and Trilobatus trilobus were moderately resistant; and Globorotalia fimbriata and Orbulina universa were most susceptible to dissolution. Presence and condition of benthic genera such as Quinqueloculina, Hoeglundina and Bulimina, and the planktonic species O. universa can be used to indicate limited dissolution in paleoceanographic studies. Small variations in the dissolution index may also reflect oceanographic changes that influence the composition of the tests, indicating the importance of regional solubility rankings, such as this study for the western South Atlantic.

Planktonic Foraminifera from southwestern Atlantic epipelagic waters: abundance, distribution and year-to-year variations

2000 ◽  
Vol 80 (2) ◽  
pp. 203-213 ◽  
Author(s):  
Esteban Boltovskoy ◽  
Demetrio Boltovskoy ◽  
Frederico Brandini
Keyword(s):  
Planktonic Foraminifera ◽  
Distribution Patterns ◽  
Similar Data ◽  
Southwestern Atlantic ◽  
Data Set ◽  
Globigerina Bulloides ◽  
Neogloboquadrina Pachyderma ◽  
Brazil Current ◽  
Southwestern Atlantic Ocean ◽  
Subsurface Waters

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.

scholarly journals A comparison between smaller (>63 μm) and larger (>150 μm) planktonic foraminiferal faunas from the Pleistocene of ODP Site 1073 (Leg 174A), New Jersey margin, NW Atlantic Ocean

2002 ◽  
Vol 21 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Christopher W. Smart
Keyword(s):  
New Jersey ◽  
Atlantic Ocean ◽  
Planktonic Foraminifera ◽  
Size Fraction ◽  
Sea Surface ◽  
General Level ◽  
Size Fractions ◽  
Globigerina Bulloides ◽  
Neogloboquadrina Pachyderma ◽  
The Mean

Abstract. Planktonic foraminiferal faunas have been studied from the Pleistocene of ODP Site 1073 (Leg 174A), New Jersey margin, NW Atlantic Ocean and their abundances have been compared in the >63 μm and >150 μm size-fractions from the same samples. Trends in the relative abundance of many species are similar in the two size-fractions, although the general level varies considerably. The mean abundance and ranges of Neogloboquadrina pachyderma (sinistral), N. pachyderma (dextral), Globorotalia inflata and Globigerina bulloides are greater in the >150 μm size-fraction compared with the >63 μm size-fraction. Turborotalita quinqueloba, Globigerinita uvula, G. glutinata, G. clarkei, and juvenile species are more abundant in the >63 μm size-fraction than the >150 μm size-fraction. Peaks (c. 60%) in abundance of G. uvula occur in the >63 μm size-fraction only, although the causes of these patterns are unclear. The data suggest that, in general, consistent palaeoclimatic/palaeoceanographic information is achieved by studying planktonic foraminiferal faunas from either size-fraction. However, because particular smaller species are either under-represented or even absent from the larger (>150 μm) size-fraction, the smaller (>63 μm) size-fraction must be included in studies of planktonic foraminifera. Furthermore, studies that involve planktonic foraminifera in the >63 μm size-fraction could provide different transfer function estimates for sea surface temperatures in areas where workers have only used larger (>125 μm and >150 μm) size-fractions.

Plankton Ecology and the Paleoceanographic–Climatic Record

1982 ◽  
Vol 17 (3) ◽  
pp. 314-324 ◽  
Author(s):  
Paul Loubere
Keyword(s):  
Deep Sea ◽  
Planktonic Foraminifera ◽  
Environmental Data ◽  
Biological Production ◽  
Globigerinoides Ruber ◽  
Neogloboquadrina Pachyderma ◽  
Fossil Material ◽  
Deep Sea Sediments ◽  
Climatic Record ◽  
Relative Abundances

AbstractThe paleoceanographic–climatic record represented by deep-sea microfossils reflects conditions for only certain times of the year. Also, the relative abundances of microfossil species in deep-sea sediments do not usually reflect only one paleoceanographic variable, such as temperature. Rather, species distributions represent the integration of many factors that control biological production in the oceans. This influences the information on past climates that can be extracted from fossil material. The seasonal limitation is due to the cyclic nature of biological production in the open ocean. Case studies of the sediment record in the Atlantic for two species of planktonic Foraminifera, left-coiling Neogloboquadrina pachyderma (Ehrenberg) and Globigerinoides ruber (d'Orbigny), illustrate seasonal bias in environmental data reported by the relative abundances of species in deep-sea sediments. In addition, the study of G. ruber illustrates the operation of two oceanographic parameters in controlling a species distribution. These examples demonstrate that the environmental signal in the sediments is the result of the interplay of the ecological tolerance of the plankton species with seasonally variable biological and physical properties of the upper ocean.

Sign in / Sign up

Export Citation Format

Share Document