• Molecular & Cellular Toxicology
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• v.4 no.4
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• pp.293-299
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• 2008

To screen the differentially expressed genes in cadmuim-exposed marine medaka fish (Oryzias javanicus), a candidate marine test fish for ecological toxicity, the differential display polymerase chain reaction (DD-PCR) was carried out, since the genome-wide gene expression data are not available in this fish species yet. A total of 35 clones were isolated from cadmium-exposed fish and their nucleotide sequences were analyzed. The differentially expressed gene candidates were categorized to response to stimulus (3); ion binding (3); DNA binding (1); protein binding (6); carbohydrate binding (1); metabolic process (4); biological regulation (3); cellular process (2); protein synthesis (2); catalytic activity (2); sense of sight (1); immune (1); neurohormone (1); signaling activity (1); electron carrier activity (1) and others (3). For real-time quantitative RT-PCR, we selected catalase, glucose-6-phosphate dehydrogenase, heat shock protein 70, and metallothionein and confirmed that cadmium exposure enhanced induction of these four genes.

• Ocean and Polar Research
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• v.21 no.2
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• pp.137-147
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• 1999

Penguins are one of the key constituent organisms in the Antarctic ecosystem. A total of 18 species of penguins occur only in the southern hemisphere from the Galapagos Archipelago to southern area off Australia and New Zealand, South Africa, South America, and the islands scattered in the Southern Ocean to the coast along the Antarctic Continent. In the Antarctic Treaty area, there are only 5 species of penguins such as Emperor (Aptenodytes forsteri), Gentoo (Pygoscelis papua ellsworthi), Adelie (P. adeliae), Chinstrap (p. antarctica), and Macaroni (Eudyptes chrysolophus) penguins. Two additional species, the King (Aptenodytes patagonicus patagonicus) and Rockhopper (Eudyptes chrysocome) penguins, however, are distributed within the Antarctic Convergence. In the vicinity of king Sejong Station located in King George Island, the South Shetland Islands off the Antarctic Peninsula, 5 species are observed, among which 2 Pygoscelis species such as the Gentoo and Chinstrap penguins hatch their eggs and raise their chicks at the rookery 2km south offing Sejong Station in summer. Adelie penguins hatch their chicks in other place in King George Island. One Emperor penguin roamed on the frozen Maxwell Bay which has been frozen every two or three years with the approximate thickness of 60cm. And one Macaroni penguin also visited the rookery in summer. We should carry out researches on the penguins occurring in the vicinity of King Sejong Station to monitor the environmental changes around King Sejong Station and the South Shetland Islands.

• Animal cells and systems
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• v.9 no.4
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• pp.205-209
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• 2005

A rapid, simple and efficient method to extract RNA from the adult polyps of a soft coral, marine cnidarian, Scleronephthya gracillimum $(K\ddot{u}kenthal)$; was developed in this study. The highest yield and purity of RNA was obtained with the lysis solution containing 35 mM EDTA, 0.7 M LiCl, 7.0% SDS, and 200 mM Tris-Cl (pH 9.0). Approximately $40{\mu}g$ of total RNA was extracted from 200 mg of liquid nitrogen-pulverized polyp tissue. The ratio of absorbance at 260 nm and 280 nm ranged from 1.8 to 2.0. The results of the reverse transcription polymerase chain reaction (RTPCR) with ${\beta}-actin$ gene specific primers and Northern blot analysis using the same gene probe revealed that the RNA extracted by our method had high quality, and was sufficient for subsequent molecular biological analyses. This method was effective for RNA extraction from other soft coral species which belong to the genus Dendronephthya.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.967-972
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• 2022

We investigated the molecular and morphological traits of 338 individual macrourids collected from the Southern Ocean (FAO area number, 88.1 and 88.3) between 2021 and 2022 by Korean bottom trawls. We first identified them as Macrourus caml and Macrourus whitsoni based on morphological traits, such as the number of pelvic fin rays (PF) and the rows of lower jaw teeth (LJT). However four individuals showed uncategorizable morphological characteristics such as PF and LJT numbers that overlapped between the two species. Subsequently, we obtained and analyzed 509 bp of the mtDNA COI sequences of 49 individuals, including the four unidentified individuals, and found only one single nucleotide polymorphism (SNP) that distinguished the two species. Finally, using our molecular identification key, we confirmed that each two individuals were misidentified as M. whitsoni and M. caml reversely. Our results suggest that the number of PF and LJT should be investigated together to accurately identify the two species.

• Journal of the korean society of oceanography
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• v.34 no.2
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• pp.59-72
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• 1999

Cavitating fluid sea ice model of Plato and Hibler (1992) is applied to the Southern Ocean with an idealized, circular Antarctica. Using climatological atmospheric forcing fields averaged in the zonal direction, we show that oceanic heat flux and ice velocity have major effects on the seasonal change of ice edge, as other studies showed. In our model results, there appears a zone of free drift that contains a polynya zone. Thermodynamic forcing functions make dominant contributions to daily increments of ice thickness and compactness, except the zones of ice edge and polynya. The dominant contributions are also shown in distributions of the temperature on ice surface and several to terms in surface heat balance equation, and are also confirmed by those obtained from the thermodynamic-only model with the different locations of ice edge.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.3 no.1
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• pp.1-9
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• 1999

Microzooplankton was analysed between $40^{\circ}s$ to $53^{\circ}s$S and $140^{\circ}E$ to $146^{\circ}E$ of the Sourthern Ocean from November 18 to November 30, 1995 to investigate the influence of frontal systems. The density and carbon biomass of microzooplankton were clearly associated with frontal systems, and at least 4 different communities were identified. The Subtropical Convergence Zone and Antarctic Polar Front Zone were the major biological boundaries recognized in the Southern Ocean. Ciliates predominated other microzooplankton in density and carbon biomass. Non-tintinnid ciliates occupied more than 70% of the total microzooplankton, and Laboea spp. was the major component of the non-tintinnid ciliates. The density and carbon biomass showed a decreasing tendency toward south from $40^{\circ}S$ to the $53^{\circ}S$ transect. The ecological importance of a frontal zone is confirmed by the microzooplanktonic data obtained from this study.

• Ocean and Polar Research
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• v.35 no.1
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• pp.63-68
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• 2013

The European Common Barnacle Balanus perforatus Brugiere (Crustacea, Cirripedia) has been introduced into the east coast of Korea, presumably via the ballast water of ships. The species has since been spreading along both the northern and southern coast to the east, most likely due to alongshore currents. We predicted the potential range expansion of Balanus perforatus in Korean waters using Genetic Algorithm for Rule-set Prediction (GARP), an environmental niche modeling technique. The results show that much of the southern coastal waters of Korea could be colonized by the spread of the nonindigenous species, but that the west coast is unlikely to be invaded. More sampling on the west coast would enhance the predictability of the model. To our knowledge, this is the first report of its kind for predicting marine nonindigenous species in Korean waters using GARP modeling.

• Ocean and Polar Research
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• v.23 no.4
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• pp.425-431
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• 2001

From an ecological point of view, the western part of the Atlantic sector is one of the most productive areas in the Southern Ocean. Antarctic krill (Euphausia superba) and krill-dependent predators such as fish, seals, and birds are abundant there, and most krill fisheries have operated in this area since 1970s. The hottest issues for the proper management of krill resources nowadays are to determine total biomass in this area, and to identify environmental forces controlling stock fluctuation. This paper reviews and collates information on ongoing oceanographic activities in the Antarctic Peninsula region concerning these issues. To delineate the status and function of Antarctic krill population in Antarctic marine ecosystems, multinational researches along the Antarctic Peninsula area have been developing recently. Four member states of CCAMLR (Japan, Russia, UK, and USA) had conducted acoustic surveys in January-February 2000 (socalled CCAMLR-2000 survey), and krill standing stock at 120 kHz was estimated to be 44.29 million metric tonnes in the western Atlantic sector of the Southern Ocean. On the other hand, the Southern Ocean GLOBEC (SO-GLOBEC) Programme has prepared a serial winter survey to examine the factors that govern krill survivorship and distribution in relation to shelf circulation processes. Ship-based surveys using ice-breakers are being conducted by three nations (Germany, UK, and USA) around the Marguerite Bay during the austral fall and winter 2001 and 2002. In addition to these two large-scale surveys, some CCAMLR members have carried out joint oceanographic surveys near the South Shetland Islands to detect ecosystem changes since 1994. Especially from December 1999 to February 2000, in conjunction with CCAMLR-2000 survey, four nations (Japan, Korea, Peru, and USA) conducted acoustic surveys to produce time-series information on krill distribution and biomass near the South Shetland areas. Though the aims of each program and the approach to solve the scientific questions were different each other, the results from each program fill the gaps between programs. Further cooperation and exchange in these activities could be beneficial to each program.

• Ocean and Polar Research
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• v.44 no.2
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• pp.127-137
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• 2022

This study examined the growth pattern and environmental factors affecting the growth of the halophyte, Suaeda japonica, which is prevalent on tidal flats in the west coast of Korea in order to calculate annual carbon production. Quantitative sampling was conducted every month for three years from 2018 to 2020 on salt marshes located on the southern coast of Ganghwa Island. In terms of annual density affected by the germination rate at first period, especially when air temperature for winter time was constantly below 0℃ for long periods of time, germination decreased and precipitation in summer also exerted an influence. In terms of annual growth with regard to length, the part below the ground grew rapidly in the beginning after budding, while the part above ground grew at a relatively steady rate at all times. With regard to biomass, the part below the ground also increased from April in a manner similar to length growth, but decreased drastically from September with leaves falling off and water loss occurring. The part above ground showed a rapid increase from the beginning of the rainy season. Size-frequency distribution revealed broader patterns after the rainy season as individual growth varied, but from September, it stopped at all year. High growth rates were recorded in the initial phase of growth after budding and growth was rapid, but growth declined in summer when biomass increased. The annual mean production based on growth rate was calculated at 352 gDWt/m²/yr, and the highest production was 519 gDWt/m²/yr in 2018, but it has decreased since 2019. Annual carbon production was at calculated 143.41 gC/m²/yr for Suaeda japonica in the vicinity of the southern coast of Ganghwa Island.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.161-166
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• 2004

Research for deposits in Nakdong eatuary that research about Nakdong eatuary's sediment flows out in Nakdong-kang so far had been progressed but research about deposits that is flowed in open sea is insufficient. Observed Nakdong eatuary's characteristic of sediment transfer through observation during the second during Buteo 20 days on February 6, 2004 in this research Resuspension bed load Flux appeared high the first result St.4 point and St.5 point. St.4 branch had much bed load amount that is flowed in the east, and bed load that St.5 branch is flowed in the south appeared much Tendency such as the first showed in the second result, but compare with the first result and St.5 branch had much bed load that is transfer in end. Bed load that is transfer in observation result Nakdong river was less. As this, can know that amount of sediment that is transfer in open sea more than deposits that is transfer in Nakdong river is much Is expected to exert effect that deposits that is transfer in open sea is high in Nakdong estuary's topography change. Specially, observation result is expected that Nakdong estuary's deposition tendency becomes Jinwoodo southern and Shinho southern.