• Journal of Fisheries and Marine Sciences Education
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• v.28 no.1
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• pp.180-185
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• 2016

To investigate the feeding habits of Tridentiger trigonocephalus juveniles captured in the intertidal zone of Dodun-ri, Seocheon-gun from the end of May to early June 2012, the gut contents were observed. Feeding incidence of the juveniles increased twice a day, first in the morning and second in the afternoon. The major food organisms of the juveniles (6.5~10.0 mm NL) were composed of copepods (65.4%), amphipods (2.0%), shrimp larvae (14.5%), polychaete larvae (22.6%), and etc. These food items held more than 2 percentage in the dry weight of the total food items.

• Ocean and Polar Research
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• v.25 no.4
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• pp.607-615
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• 2003

Many organisms are known to survive in icy environments. These include both over wintering terrestrial insects and plants as well the marine fish inhabiting high latitudes. The adaptation of these organisms is both a fascinating and important topic in biology. Marine teleosts in particular, can encounter ice-laden seawater that is approximately $1^{\circ}C$ colder than the colligative freezing point of their body fluids. These animals produce a unique group of proteins, the antifreeze proteins (AFPs) or antifreeze glycoproteins (AFGPs) that absorb the ice nuclei and prevent ice crystal growth. Presently, there are at least four different AFP types and one AFGP type that are isolated from a wide variety of fish. Despite their functional similarity, there is no apparent common protein homology or ice-binding motifs among these proteins, except that the surface-surface complementarity between the protein and ice are important for binding. The remarkable diversity of these proteins and their odd phylogenetic distribution would suggest that these proteins might have evolved recently in response to sea level glaciations just 1-2 million years ago in the northern hemisphere and 10-30 million years ago around Antarctica. Winter flounder, Pleuronectes americanus, has been used as a popular model to study the regulation of AFP gene expression. It has a built-in annual cycle of AFP expression controlled negatively by the growth hormone. The signal transduction pathways, transcription factors and promoter elements involved in this process have been studied in our laboratory and these studies will be presented.

• Ocean and Polar Research
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• v.31 no.4
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• pp.349-357
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• 2009

Ballast water is widely recognized as a serious environmental problem due to the risk of introducing non-indigenous aquatic species. In this study we aimed to investigate measures which can minimize the transfer of aquatic organisms from ballast water. Securing more reliable technologies to determine the viability of aquatic organisms is an important initiative in ballast water management systems. To evaluate the viability of marine phytoplankton, we designed the staining methods of fluorescein diacetate (FDA) and Calcein-AM assay on each target species belonging to different groups, such as bacillariphyceae, dinophyceae, raphidophyceae, chrysophyceae, haptophyceae and chlorophyceae. The FDA method, which is based on measurements of cell esterase activity using a fluorimetric stain, was the best dye for determining live cells of almost all phytoplankton species, except several diatoms tested in this study. On the other hand, although fluorescence of Calcein-AM was very clear for a comparatively longer time, green fluorescence per cell volume was lacking in most of the tested species. According to the Flow CAM method, which is a continuous imaging technique designed to characterize particles, green fluorescence values of stained cells by FDA were significantly higher than those of Calcein-AM treatments and control, implying that the Flow CAM using FDA assay could be adapted as an important tool for distinguishing living cells from dead cells. Our results suggest that the FDA and Calcein-AM methods can be adapted for use on phytoplankton, though species-specific characters are greatly different from one organism to another.

• Journal of the korean society of oceanography
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• v.38 no.4
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• pp.211-215
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• 2003

A huge freshwater reservoir (ca. 12,000 ha) will be created when the construction of a 33­km dike on a huge mud flat of the Saemankeum areas is established. A large quantity of freshwater will emerge to the adjacent sea from the reservoir through two big gates. Marine organisms outside the dike are expected to frequently experience low salinity waters. To investigate the salinity effects on the dominant metazooplankton in the coastal waters off Saemankeum areas, we measured the survival (Survival 1H and Survival 24H) of 11 different taxa (the copepods Acartia omorii, A. pacifica, Calanus sinicus, Centropages abdominalis, Paracalanus indicus, Pseudodiaptomus inopinus, Tortanus forcipatus, and a hydromedusa, and barnacle nauplius, polychaeta larva, and a chaetognath Sagitta sp.) at salinities of 0, 5, 10, 15, 20, 25, 30, 35, and 40 psu when the organisms were exposed for 1 and 24 h, respectively. Survival 1Hs of P. inopinus and barnacle nauplius were 100% between 5 and 35 psu, while they were 0% at salinities of 0 and 40 psu. Survival 1Hs of A. omorii and A. pacifica, P. indicus, T. forcipatus, and polychaeta larva were 100% at $salinities\;\geq\;10$ psu, while they were 0% at lower salinities. Survival 1Hs of a hydromedusa and Sagitta sp. were 100% at $salinities\;\geq\;15$ psu, while they were 0% at lower salinities. Survival 1H of C. abdominalis and C. sinicus was 100% at $salinities\;\geq\;20$ psu, while they were 0% at lower salinities. Survival 24Hs of A. omorii, A. pacifica, C. abdominalis, barnacle nauplius, and polychaeta larva were the same as Survival 1 Hs at the same salinity, while those of the other metazooplankton were lower than Survival 1Hs. The results of the present study suggest that low salinity water emerging from big gates may cause the death of the metazooplankton, but the salinities at which death of the metazooplankton occurs may differ by species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.716-722
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• 2003

This study determined the optimum dosage for coagulation reactions of red tide organisms (RTO) using a combination of ignited oyster shell powder (10sp) and loess and examined the electrokinetic and rheological characteristics of their flocs. Two kinds of RTO, Cylindrotheca closterium and Skeletonema costatum, were sampled in Masan Bay and cultured in the laboratory. Coagulation experiments were conducted using various concentrations of IOSP, loess, IOSP+1oess, RTO, and a jar tester RTO cell numbers were counted for both the supernatant and RTO culture solution. The removal rates increased rapidly with increasing IOSP concentrations up to 50 mg/L and loess concentrations up to 800 mg/L. A removal rate of $100\%$ was reached at 400 mg/L of IOSP and 6,400 mg/L of loess. The highest increment $(16.7\%)$ of the rates of coagulation reaction occurred using both IOSP and loess (50+200 mg/L) in comparison with IOSP alone. The rate of coagulation reaction using both IOSP and loess (50+200 mg/L), $90.6\%,$ was similar to employing either IOSP of 150 mg/L or loess of 3,200 mg/L. All of the coagulation liquids for RTO, IOSP (200 mg/L), loess (200 ma/L), and IOSP+1oess (200+200 mg/L) revealed non-Newtonian fluid properties and therefore their shear rate vs. shear stress curves were non-linear. The coagulation liquids revealed elastic body properties at a lower shear rate increasing in the following order: RTO, IOSP (200 mg/L), loess (200 mg/L), and IOSP+1oess (200+200 mg/L. IOSP+1oess (200+200 mg/L) especially demonstrated plastic flow properties at a lower shear rate.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1444-1458
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• 2016

The expansion of high-density aquaculture in the limited waters has caused a wide variety of problems. The problems include environmental problems nearby aquaculture sites, growth rate of aquatic organisms, quality decline of farmed fish and price fall in the market. The phenomenon of aquaculture industry happens in not only inshore but also offshore. Therefore, the fisheries authorities have been changing their policy paradigms from mass production to sustainable production based on ecosystem. Other countries, however, focusing on relieving poverty and providing protein from fish production have not recognized the degree of seriousness. When it comes to enhancing the problems, National Institute of Fisheries Science has been developing the technology of Integrated Multi-Trophic Aquaculture (IMTA) to reduce and to prevent contaminants from fish and aquaculture sites, remained feed from fish farming process. In long-terms of view, the system is one of the most sustainable fishery production methods based on ecosystem. As integration of nutrient feed system from aquatic organisms is firmly established, the earlier mentioned problems will be diminished gradually. In term of the substantiality, this study was conducted. The research on management system for IMTA also has been incorporated. This study also investigated the features and current status of IMTA and demonstrated the developed management system and direction for the future advancement.

• Journal of the Korea Fashion and Costume Design Association
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• v.15 no.1
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• pp.91-109
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• 2013

The main objective of this research was to understand the latest trends of natural print design through the quantitative & qualitative analysis of fashion appeared in contemporary female collections. The research criteria was defined as 3 seasons from 2011 S/S to 2012 S/S. Data collection of 726 was done through review of 'pr$\hat{e}$t-$\grave{a}$-porter Collections' of three major fashion cities; Paris, Milan and NY. Statistical analysis of frequency with chi-square test was conducted. Also qualitative interpretation of natural print design' characteristics was completed. The main findings were as follows.; The average occurrence rate of natural print design from 2011SS to 2012 SS in three collections were 6.4% in Milan 6.4%, 5.5% in Paris and 6.8% in N.Y. The five source types of natural prints in contemporary women's fashion collections were identified and the order of their appearance were as follows: flowers, plants, animals, insects & marine organisms and compound one. The plant prints were expressed by stylized or realistic touch. Flower patterns showed more variables than plants, however, there were no big difference in their image and major characteristics. The animal prints demonstrated two aspects. First one used typical animal print of fur or skin, but the other one draw the animal figure like paintings. The compound source type presented the most interesting and fresh pattern design ideas. In the insects & marine organisms, mainly butterfly and seashell & starfish, etc. appeared as real shapes or sometimes were stylized.

• Development and Reproduction
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• v.22 no.1
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• pp.111-117
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• 2018

The objective of this study was to determine the mitotic intervals (${\tau}_0$) of two consecutive cell divisions and synchronous embryonic cleavage in grass puffer, Takifugu niphobles at different water temperatures (18, 20, 22, and $24^{\circ}C$). The color of the fertilized egg was light yellowish. The egg type was demersal and unadhesive. Egg weight was $0.09{\pm}0.002mg$. The sizes of unfertilized eggs were smaller than fertilized eggs in major axis and minor axis at $20^{\circ}C$ (p<0.05). The size of the fertilized egg of $18^{\circ}C$ water temperature group at the blastodisc stage was the smallest (p<0.05), but no significant differences were observed in the other water temperatures group except $18^{\circ}C$ water temperature group (p>0.05). The first cleavage stages at 18, 20, 22, and $24^{\circ}C$ were at 75, 90, 105, and 120 mins, respectively. As water temperature was increased, embryonic development and formation time of the first cleavage furrow were accelerated. There were negative correlation between ${\tau}_0$ and water temperature for grass puffer (Y=-1.225X+70.05, $R^2=0.988$, n=10, where Y was ${\tau}_0$ and X was temperature). This study confirmed that successful hatching of grass puffer was related to water temperature. Chromosome manipulation will be helpful for this species using cleavage frequency and ${\tau}_0$.

• Ocean and Polar Research
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• v.40 no.4
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• pp.281-288
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• 2018

The transmission of solar light according to the distribution of chromophoric dissolved organic matter (CDOM) was measured in the Pacific Arctic Ocean. The Research Vessel Araon visited the ice-covered East Siberian and Chukchi Seas in August 2016. In the Arctic, solar [ultraviolet-A (UV-A), ultraviolet-B (UV-B), and photosynthetically active radiation (PAR)] radiation reaching the surface of the ocean is primarily protected by the distribution of sea ice. The transmission of solar light in the ocean is controlled by sea ice and dissolved organic matter, such as CDOM. The concentration of CDOM is the major factor controlling the penetration depth of UV radiation into the ocean. The relative CDOM concentration of surface sea water was higher in the East Siberian Sea than in the Chukchi Sea. Due to the distribution of CDOM, the penetration depth of solar light in the East Siberian Sea (UV-B, $9{\pm}2m$; UV-A, $13{\pm}2m$; PAR, $36{\pm}4m$) was lower than in the Chukchi Sea (UV-B, $15{\pm}3m$; UV-A, $22{\pm}3m$; PAR, $49{\pm}3m$). Accelerated global warming and the rapid decrease of sea ice in the Arctic have resulted in marine organisms being exposed to increased harmful UV radiation. With changes in sea ice covered areas and concentrations of dissolved organic matter in the Arctic Ocean, marine ecosystems that consist of a variety of species from primary producers to high-trophic-level organisms will be directly or indirectly affected by solar UV radiation.

• Ocean and Polar Research
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• v.45 no.3
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• pp.125-140
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• 2023

We investigated meiofaunal biofouling (40-1,000 ㎛) on stranded marine plastic debris (hereafter MPD) collected from 8 coastal areas highly affected by plastic pollution located in the southern part of Korea during June, 2021, in order to analyze the abundance and composition of MPD associated organisms. A total of eight shapes of MPD was collected and classified into four types of plastics (LDPE, PET, PP and EPS) based on Resin Identification Coding System. Meiofounal biofouling was identified into 35 taxa belonging to 11 phylum, 10 classes and 12 order, and were numerically dominated by harpacticoids (EPS: 21.6%, PP: 27.1%), nematodes (LDPE: 23.2%) and foraminiferans (PET: 29.6%). Surface area of MPD was negatively correlated with abundances of organisms on the plastic debris (r = -0.487, p < 0.05, n = 24), indicating that abundances (avg. 3,225 inds. 0.1 m^-2) on the smallest area of PP debris (avg. 0.0208 m² ) were higher than those (avg. 50 inds. 0.1 m^-2) on the largest area of LDPE debris (avg. 0.4029 m^-2). Whereas, there was no correlation between surface area of MPD and the number of taxa on the debris (r = 0.147, p = 0.49, n = 24). These results showed that higher abundances of meiofaunal biofouling were observed on the PP material debris than those on the other debris collected from eight hot spots of the southern coastal waters in Korea, associated with not only polymer type and surface area of the PP debris, but also possibly surface microstructure of the PP debris.