• Journal of the korean society of oceanography
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• v.34 no.1
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• pp.43-48
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• 1999

The latest-Quaternary paleoceanographic history of the Ulleung Basin, the East Sea (the Sea of Japan) is reconstructed on the base of planktonic foraminifera, oxygen and carbon isotopes, and accelerator mass spectrometer radiocarbon (AMS-$^{14}$C) data from two cores. Sinistral populations of Neogloboquadrina pachyderma are dominant during the last glacial period while dextral forms of Neogloboquadrina pachydeyma are abundant in the Holocene. An abrupt increase in ${\delta}^{18}$O values in both cores that began about 11 ka B.P may indicate the Younger Dryas cooling episode. A low-salinity event, marked by light ${\delta}^{18}$O values (0-1 %), is observed before the Younger Dryas event. As previous works suggested, the low-salinity event is probably due to the freshening of surface water caused by fresh water input from Huang Ho river and/or the excess of precipitation over evaporation. The lowest salinity water in the Ulleung Basin was probably continued from approximately 18 ka B.P. to 15 ka B.P. The ${\delta}^{18}$O values have gradually decreased since the Younger Dryas as a result of the continuous inflow of the warm Tsushima Current into the East Sea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.338-343
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• 2018

Recently, commercial catches of the common squid Todarodes pacificus have dramatically decreased in Korean and Japanese waters. The relationship between common squid catches and environmental factors was investigated using squid catches, climate indices and observed seawater temperatures in Korean waters. Common squid consist of three spawning stocks: autumn, winter, and summer. The autumn stock is the largest in Korea, and its main fishing season appears to have shifted from September in the 1980s to October in the 1990s. We observed negative correlations between the spring Southern Oscillation Index and Korean catches and between the winter Pacific Decadal Oscillation and Japanese catches. Despite global warming, no conspicuous increases in October seawater temperatures have been observed at 10 and 50 m in Korean waters since the mid-1900s. Instead, the 50 m water layer of the East Sea appears to be gradually cooling. Moreover, temperatures at 50 m in the East Sea and the South Sea were significantly negatively correlated with squid catches in Korea and Japan, respectively. Our preliminary analysis indicates a link between climate change, seawater temperature, and squid catches in Korean waters, which helps to inform the direction of subsequent research to identify the cause of rapid decreases in this squid resource.

• ALGAE
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• v.31 no.3
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• pp.231-241
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• 2016

We examined the genetic diversity and abundance of picocyanobacteria using barcoded amplicon sequencing approaches and flow cytometry in the East Sea and the East China Sea to determine the distribution patterns of diversity during spring in seas adjacent to the Korean Peninsula. Synechococcus clades I and IV, which have been known as cold-adapted ecotypes, dominated at most stations. However, the relative abundances of the two dominant clades differed in their spatial patterns. Clade I was exclusively dominant in the shelf area of the East China Sea and the north East Sea. However, the dominant genotypes belonging to clade I had different spatial distributions in the two areas and responded oppositely to seawater temperature. The dominance of distinct genotypes under the different ecological conditions suggests the presence of ecologically different ecotypes within the clade. Abundances of clade IV were greater than those of clade I at most stations in the southwest East Sea, showing an apparently different pattern from that of the other areas. A warm-water adapted clade II was observed at significant levels only at stations located in the eastern East China Sea affected by a branch of the warm Kuroshio Current. These results suggest that the physicochemical properties of influencing water masses play an important role in determining the distribution of Synechococcus genotypes.

• Animal Systematics, Evolution and Diversity
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• v.20 no.2
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• pp.87-98
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• 2004

Two pagurid hermit crabs of the genus Pagurus, P. proximus Komai, 2000 and P. simulans Komai, 2000, were collected from the East Sea of Korea are reported. Brief descriptions and illustrations of these two species are provided. Both have been confounded with P. brachiomastus (Thallwitz, 1891) until recently Komai (2000a) reviewed the taxonomic status of this species complex. Kim's (1973) record of P. brachiomastus from Korea was synonymized to P. proximus by Komai (2000a) and the latter in Korean waters is confirmed through this study. P. simulans is recorded for the first time from Korea as well as the East Sea (Sea of Japan).

• Journal of the Korean Geographical Society
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• v.47 no.6
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• pp.870-883
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• 2012

This study aims to summarize recent discussions on naming the sea between Korea and Japan and to draw some research topics of the geographical toponymy. The International Hydrographic Conference and the United Nations Conference on the Standardization of Geographical Names held in 2012 repeatedly saw clearly different positions of Korea and Japan on the naming of the sea. From the debates, four topics appeared distinctly which deserve receiving continuous interests in the field of geographical toponymy. These include: necessity of dual naming and characteristics of, and perceptions on the object of dual naming; political economic nature of the sea, e.g. semi-enclosed sea, EEZ, and relevant use of names; relationship between the sea containing strong emotional ties and its naming; additional definition of toponymic terminologies to proceed with more objective and logical discussions.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.34
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• pp.109-131
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• 2007

This paper has focusing CheongHaeJin's maritime trading activities between Korea, China and Japan in the 9th century. In operation of CheongHaeJin which Chang BoGo was given a key role, CheongHaeJin creates three nation's wealth in triangular trade among Korea, China and Japan. And also, CheongHaeJin's contribution is considerable to the maritime trade development of Northeast Asia through establishing trading advance base in China and Japan, and organizing Shilla's people in China. Chang BoGo justified the control over small business groups of the west and south sea of Korea and the east and south sea of China by keeping pirates away His trade groups controlled foreign trade of three countries: Shilla, the Dang Dynasty of China and Japan. They connected Persia, India, Southeast Asia, and China. CheongHaeJin's key success factors of the maritime activities are summarized as follows; There is a possibility of searching that successful factor from the people of operator of CheongHaeJin. Based on oceanic adventurous spirit with character and progressive thinking could complete the rally of sea influence and composition of fleets. Secondly, the success factor is the excellent operational ability and leadership which learned in the Dang Dynasty of China. Thirdly, In 9th century, International political context was suitable for CheongHaeJin's construction and operation. Such political circumstances had given to CheongHaeJin remunerative position. Finally, Although central government could not maintain the sea traffic securities, Chang BoGo's ocean trading fleets guaranteed the safe fishing industry of people and security of sea traffic.

• Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.69-86
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• 2023

The bioactive secondary metabolites produced by sea cucumbers are very diverse with differences in composition, linkages, molecular weight, and various functional properties. Due to their physicochemical properties, these bioactive molecules in sea cucumbers have found applications in various market segments such as functional foods and cosmetics. Sea cucumber side dishes are a prominent food item in traditional cuisine in East Asian countries such as South Korea, China, and Japan. In addition, many studies have reported that the consumption of sea cucumbers can reduce the risk of cardiovascular disease, the pathogenesis of cancer cells, chronic inflammatory diseases, etc. In particular, many studies have recently reported the potential of sea cucumbers to develop functional products to reduce inflammation, oxidative stress, diabetes, and cancer. Additionally, these bioactive properties associated with sea cucumbers make them ideal compounds for use as functional ingredients in functional food products. However, no report has yet reviewed the properties of sea cucumbers related to functional foods. Therefore, in this review, the primary focus is given to collecting published scientific data (from 2019 to 2023) on the bioactive properties of sea cucumbers relevant to the functional food industry.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.70
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• pp.67-80
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• 2016

As China, the world's work shop was transformed into consumption market intermediary products and expensive consumer goods are more in highly demand recently. These will tend to diffuse especially to the west coastal cities of China. The economic growth of China needs to develop hub port facilities more and more in these days. We don't need to explain value of hub port in international trade. Furthermore If we are to retain access convenience of merchant vessel we really must maintain hub ports in Korea. This paper aims to vitalize Pyeongtaek port in times of the Pan Yellow Sea in readiness for an increase of trade between Korean, China, and Japan absorbing economic effects. The Rise of China leads to increase of trade of Korea that make necessary to develop a big and wide port to Pan Yellow Sea times. There is a lot of competition to be a hub port to become a center of international trade in the Pan Yellow Sea market. We need to improve the surrounding environment or facilities and industry clusters flexibly of Pyeongtaek port. It will guide to cost cutting and to raise business efficiency. Ultimately Pyeongtaek port should maintain and make advance its competitiveness especially in the Pan Yellow Sea times.

• Animal Systematics, Evolution and Diversity
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• v.7 no.1
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• pp.127-150
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• 1991

The stony corals known from Korean waters are 24 species , 15 genera, 7 families in 5 suborders, of which 7 species are newly recorded to the Korean scleractinian fauna ; Montipora trabeculata, Oulangia stokesiana miltoni, Goniocorella dumosa, Dendrophyllia arbuscula, D.boschmai cyathohelioides, D. micranthus, and Rhizopsammia minuta mutsuensis. They were collected from 35 localities of southern Korea from 1969 to 1986. For the geographical analysis, the coastal waters of Koarea are divided into four regions ; the Yellow Sea, the Korea Strait, the Cheju Island area and the East Sea (Sea of Japan) . These are based on the species diversity , the geographical distribution form, and the community coefficient, Korean scleractinians consists of 8 temperate zone forms(33.3%, Te) and 16 tropical forms(66.7%, Tr) . Concerning the distribution in each region, 3 spp. (2 Te, 1 Tr) occur in the Yellow Sea, 9 Spp. (5 Te, 4 Tr) in the Korea Strait, 16 spp.(4 Te, 12 Tr) in the Cheju Island area and 5 spp. (2 Te, 3 Tr) in the East Sea. The communicty coefficient between the Korea strait and the East Sea is the highest (0.596), and that between the Yellow Sea and the Cheju Island area is the lowest(0).

• Proceedings of the KSRS Conference
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• v.1
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• pp.316-319
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• 2006

Monthly-mean aerosol parameters derived from the 1998-2004 SeaWiFS observations over East Asian waters are analyzed. SeaWiFS GAC Level 1 data covering the Northeast Asian area are collected and processed by the standard atmospheric correction algorithm released by the SeaWiFS Project to produce daily aerosol optical thickness (AOT) and ${{\AA}}ngstr{\ddot{o}}m$ exponent imageries. Monthly mean AOT and ${{\AA}}ngstr{\ddot{o}}m$ exponent values are extracted from the daily composite images for six study areas chosen from the surrounding waters of Japan. A slight increasing trend of ${{\AA}}ngstr{\ddot{o}}m$ exponent is found and interpreted as about 4-5% increase in submicron fraction of aerosol optical thickness at 550nm. Two cloud screening methods, including the standard cloud masking method of SeaWiFS and the one based on the local variance method, are applied to the SeaWiFS data processing, in an attempt to inspect the influence to the observed statistical uptrend which probably induced by different cloud mask algorithms. The variability comes from the different cloud masking algorithms are discussed.