• Ocean and Polar Research
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• v.35 no.2
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• pp.181-191
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• 2013

To investigate the occurrence of modern living planktonic foraminiferal species and their seasonal variations around Jeju Island, we conducted planktonic foraminiferal sampling at KIOST's regular sampling sites during 16 months. In total seven genus and 16 modern planktonic foraminiferal species were identified with six dominant species. Dominant species were Gloigerinoides sacculifer, Globigerinoides ruber, Globigerina bulloides, Noegloboquadrina dutertrei, Pulleniatina obliquiloculata, and Globorotalia inflata. Most of the species were characterized as being typical subtropical species and showed seasonal variations and/or intermittent occurrence from season to season. The occurrence of living foraminifera revealed a strong relationship with water temperature, but not with salinity. Species succession seems to occur along with water temperature changes. Some patch distribution and water temperature dependences appear to be significant since there is a high degree of variation in the occurrence patterns of species and standing stock. More detailed quantitative study is necessary to confirm the species diversity and seasonal variations of planktonic foraminifera and related ocean environmental changes.

• Journal of Species Research
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• v.8 no.4
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• pp.389-394
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• 2019

Foraminifera are protists that inhabit diverse marine environments and show high abundance and diversity. However, previous studies on foraminifera in Korea mostly focused on geological and paleoecological fields and were conducted in a limited area. Therefore, there is a high possibility for discovering new and unrecorded species. Here we describe three newly recorded foraminiferal species from the southwestern part of Jeju Island during a survey on the meiofaunal community, which belongs to three different genera (Ammobaculites, Cylindroclavulina, Saracenaria), three families (Lituolidae, Vaginulinidae, Valvulinidae), and three orders (Lituolida, Textulariida, Vaginulinida): Ammobaculites formosensis Nakamura, 1937, Cylindroclavulina bradyi (Cushman, 1911), and Saracenaria hannoverana (Franke, 1936). These species have been reported from Chinese region in the East China Sea, however this is the first report from Korean waters. Particularly, Cylindroclavulina bradyi is the first report of the genus Cylindroclavulina in Korean waters. The present study supports the diversity of foraminiferal species in Korea, and the necessity of further surveys in Korean waters.

• Journal of Species Research
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• v.12 no.1
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• pp.48-54
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• 2023

Foraminifera are unicellular eukaryotes widely distributed in marine and transitional marine environments. They play important roles in marine food webs and geochemical cycles and have physiological properties like the formation of calcareous tests and nitrogen respiration. Research on species diversity, distribution and endemism are essential in biogeography and biodiversity conservation. Here, we report three unrecorded species of foraminifera (Hemirotalia foraminulosa, Planispirillina denticulogranulata and Oolina brevisolenia) collected from Jeju Island and the South Sea (Korea). Planispirillina denticulogranulata is the second Planispirillina species recorded in Korea, which can be distinguished from congeners by its tubercles on the ventral side and grooves on the spiral suture. Hemirotalia foraminulosa is differentiated from the only congener H. calvifacta by multiple-scattered pits on the umbilicus, and it is the first report of Hemirotalia from Korean water. Oolina brevisolenia has specific bifurcating costae that characterize it from other congeners. This study contributes to documentation of the foraminiferal biodiversity in Korea, moreover, provides an essential basis for the expanded studies on modern foraminifera.

• The Korean Journal of Quaternary Research
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• v.21 no.2
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• pp.74-76
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• 2007

The modern foraminiferal distribution patterns and species diversity in surrounding seas of Korea are controlled by winter monsoon and characteristics of water masses. Abrupt climate change, Younger Dryas cold episode" is identified in Korea. The Younger Dryas is characterized by local extinctions of foraminifera. Several record-breaking climate phenomena observed in Korea, especially September, 2007.

• Journal of the korean society of oceanography
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• v.34 no.3
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• pp.144-150
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• 1999

Slope sedimentation on the modern west Florida continental margin is controlled by pelagic carbonate accumulation and off-shelf sedimentation of neritic carbonates and terrigenous fines. Production and deposition of pelagic carbonates by planktonic foraminifera and coccoliths have played a significant role in the total slope sedimentation and are mainly promoted by sea-surface productivity. Organic carbon data reflect the relatively high biological productivity in surface waters, indicating high accumulation of biogenic calcareous sediments. The surface-water productivity in the study area is supported by the relation among microfossil assemblages, carbonate mineralogy and sedimentary organic carbon.

• Journal of the korean society of oceanography
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• v.37 no.1
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• pp.27-34
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• 2002

We measured the alkenone concentration of bulk sediments from a piston core collected from the Ulleung Basin in the East Sea in order to reconstruct past sea surface temperatures (SST). Sediment ages are well constrained by AMS $^{14}C$ dates of the planktonic foraminifera Globigerina bulloides. Coretop alkenone SST calibration with modern surface temperatures and sediment trap dat (Hong et al., 1996) indicate that the SST estimated from alkenones most likely represent the temperatures of late fall. Downcore variations in the alkenone saturation index indicate that between 19 and 15 kyr BP the surface waters were about $3^{\circ}C$ warmer than today. Between 15 and 11 kyr BP, the temperatures were about $3^{\circ}C$ lower than today. A rapid SST increase of about $3^{\circ}C$ occurred at approximately 10 kyr BP. After considering the factors which might influence the SST reconstruction from the $U^{k'}_{37}$ values, we conclude that the alkenone temperature estimates are reliable. The reason for glacial warming in the East Sea is not clear, although there is a possibility that it could be caused by shift in the season of maximum alkenone production from summer during the last glaciation to late fall during the Holocene. Cooling between 15 and 11 kyr BP may be due to inflow of cold water into the East Sea such as via the Oyashio Current or ice-melt water. Warming at the early Holocene could be due to inflow of the Tsushima Current into the East Sea through the Korea Strait.