• ALGAE
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• v.34 no.1
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• pp.45-56
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• 2019

Ecklonia cava (EC) has been widely utilized as an ingredient in commercial products such as functional foods and cosmeceuticals. Recently it has been found that Sargassum horneri (SH) has been invading on Jeju Island coast area by its huge blooming. Moreover, both seaweeds are considering as important ingredients in traditional medicine specifically in East-Asian countries (China, Japan, and Korea). In the present study, we attempted to compare anti-inflammatory properties of 70% ethanolic extracts of EC (ECE), SH (SHE), and their different combinations on lipopolysaccharide (LPS)-activated RAW 264.7 cells. Results indicated that 8 : 2 combinations of ECE : SHE significantly inhibited LPS-activated inflammatory responses (cytokines, protein, and gene expression) in RAW 264.7 macrophage cells compared to the respective extracts and other combinations. The synergistic effect of ECE and SHE was found to be prominent than the effects of ECE or SHE alone. These observations provide useful information for the industrial formulation of functional materials (functional foods and cosmeceuticals) using these two particular seaweeds in Jeju Island of South Korea.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.509-510
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• 2014

본 연구 개발에서는 육로가 아닌 바다에서의 해양 환경 상태와 어선의 운행 시 사고 영상을 저장 확인할 수 있는 소형 어선용 영상저장 및 환경 데이터 저장 Set-top Box를 개발하고자 한다. 소형어선들은 매우 필요하나 장비의 고가로 인하여 구축하기가 어려워 저가의 장비의 개발은 필수적이다. 이를 기반으로 현재 해양경찰에서 사용하고 있는 무선통신 방식과 접목하여 사고나 위험한 상황 시 해양경찰이나 관제센터로 영상 및 데이터를 전송하여 해양에서 얻을 수 있는 각종 해양 환경정보 및 각 선박들의 안전에도 기여하고자 한다.

• Fisheries and Aquatic Sciences
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• v.26 no.12
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• pp.698-707
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• 2023

Fish are an essential resource in human society, and while ecological research on them is challenging, it is absolutely necessary. Recent technologies enabled researchers to monitor underwater fish behavior. Acoustic signals, satellite-mediated location estimation, and light-based geolocation are powerful tools for tracking fish movements from freshwater to deep-sea habitats. These tools allow us to track various fish species and elucidate their ecology. Furthermore, based on these technologies, we can develop fisheries management plans and enhance aquaculture productivity. In this review, we also discuss challenges in improving current technologies and provide future recommendations for fish bio-logging studies.

• Korean Journal of Ichthyology
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• v.30 no.1
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• pp.55-64
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• 2018

Fish assemblages in a sandy shore and an eelgrass bed were compared based on monthly samples in the southern coastal water of Korea. Samples were collected by a beam trawl in the sandy shore and a surf net in the eelgrass from March to February 2012. The common fish species were Syngnathus schlegeli, Pseudoblennius cottoides, Pholis nebulosa, Favonigobius gymnauchen, Gymnogobius heptacanthus, Pseudopleuronectes yokohamae, Takifugu niphobles. Among them S. schlegeli, Urocampus nanus, P. cottoides, P. nebulosa, T. niphobles were high abundance in the eelgrass bed than in the sandy shore, whereas Acanthogobius flavimanus, Acentrogobius pflaumi, F. gymnauchen, G. heptacanthus, P. yokohamae were high in the sandy shore. Aulichthys japonicus, Hippocampus coronatus, Sebastes inermis, Lateolabrax japonicus, Siganus fuscescens were found in the eelgrass bed, and Thryssa hamiltoni, Mugil cephalus, Inimicus japonicus, Platycephalus indicus, Hexagrammos otakii, Furcina ishikawae, Liparis tanakae, Repomucenus curvicornis, and Eutaeniichthys gilli were observed in the sandy shore. Species composition and abundance varied seasonally in two habitats; The number of species and abundance was high in August and September, while biomass was the highest in April and September. Fish numbers as well as biomass were lowest in February. Number of individuals and biomass of fish in the eelgrass bed were significantly higher than those of in the sandy shore. Some fish preferred to live in the eelgrass were collected in the sandy shore, while fish preferred to live in the sandy shore were rarely collected in the eelgrass.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.1
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• pp.103-108
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• 2015

Recent global warming has been recognized as the world economy development from fossil fuel use is the culprit. This study was reduce the fossil fuel has been developed in a number of alternative energy, As a fuel that can be produced in our country is a biofuel. Biofuels is a sustainable fuel having economically benefits and decreasing environmental pollution problems caused due to fossil fuel. A lot of research is progressing about the conversion of diesel biofuel as renewable clean energy. In this experiment were remodel the institution that has been used in fishing engine again produced an experimental apparatus were installed directly, were studied using various bio fuel like to help the economically and environmentally sound operation of the vessel. rapeseed oil, soybean oil, comprehensively analyzing the results the effects of the exhaust emission characteristics of the waste rapeseed oil is available in a marine engine with similar physical and chemical components of the fuel, and the fuel consumption ratio, NOx is slightly increased, but soot was confirmed a tendency to decrease much.

• Ocean and Polar Research
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• v.37 no.1
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• pp.61-71
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• 2015

Eicosapentaenoic acid (EPA) produced from marine organisms is widely used in nutraceuticals. Monodus subterraneus and Nannochloropsis oceanica, which are representative freshwater and marine Eustigmatophyceae, respectively, are known to have a high content of protein and lipid, particularly, EPA. In this study, to compare the growth and nutritional composition of M. subterraneus and N. oceanica, they were cultured in autotrophic and mixotrophic conditions with JM and f/2 medium, respectively, at $25^{\circ}C$. In addition, $80{\mu}mol\;photons\;m^{-2}s^{-1}$ with 24-hour and 12-hour light was provided, with the addition of 2% glucose to the medium for the mixotrophic culture. With regard to growth, M. subterraneus showed 10 times higher biomass in a mixotrophic culture than in an autotrophic one. However, no significant difference was observed for N. oceanica between the two culture methods. With respect to nutritional composition, M. subterraneus cultured autotrophically had a higher protein and lipid content, particularly EPA, than that cultured mixotrophically, but no significant difference was found in the two cultures of N. oceanica. Furthermore, M. subterraneus cultured autotrophically with continuous light showed higher nutritional composition, particularly EPA, than N. oceanica. In conclusion, the mass culture of freshwater M. subterraneus is much easier and more economical than marine N. oceanica. In addition, production of EPA will be economically improved if mixotrophic culturing of M. subterraneus is first conducted to maximize the biomass, and then secondary autotrophic culturing is performed.

• Toxicological Research
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• v.21 no.4
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• pp.361-365
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• 2005

This study was conducted to obtain the acute information of the oral dose toxicity of Polycan - originated from Aureobasidium pullulans SM-2001 (half of the dry material is -1,3/1,6-glucans), a UV induced mutant of A. pullulans, having various pharmacological effects, in male and female mice. In order to calculate $50\%$ lethal dose $(LD_{50})$, approximate LD and target organs, test article was administered twice by oral gavage to male and female ICR mice at total 1000, 500 and 250mg/kg. The mortality and changes on body weight, clinical signs and gross observation were monitored during 14 days after dosing. As the results, we could not find any mortalities, clinical signs, changes in the body weight and gross findings. The results obtained in this study suggest that the Polycan is non-toxic in mice and is therefore likely to be safe for clinical use. The L050 and approximate $(LD_{50})$ in mice after single oral dose of Polycan were considered over 1000 mg/kg, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.4
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• pp.620-627
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• 2020

Oxygen consumption and blood physiology of olive flounder Paralichthys olivaceus (mean body weight 106.6±6.8 g, mean±SD) was investigated at salinities of 34.0 (control), 33.7, 33.3, 32.6, 31.3, 28.6, 23.1, 12.2 and 0.0 psu at 20.0℃, respectively. Stepwise salinity changes (34.0→33.7→33.3→32.6→31.3→28.6→23.1→12.2→0.0 psu) with an interval of 24 h for each salinity induced a significant (P<0.05) increase of oxygen consumption rate (OCR) in fish exposed from 31.3 to 0.0 psu compared to that of control fish. The maximum OCR was found in fish exposed to 23.1 psu, which was accompanied by 36.2% higher energy consumption than the control fish. Fish exposed to each salinity for 24 h induced a significant decrease of blood plasma Na⁺ in 0.0 psu and Cl^- in 12.2 and 0.0 psu (P<0.05), and increase of plasma glutamic oxaloacetic transaminase (GOT) in 0.0 psu compared to the control fish (P<0.05). The results of this experiment show that P. olivaceus exposed to concentrations below 31.3 psu requires more energy costs to adapt to salinity changes than 34.0 psu under our experimental conditions.

• Ocean and Polar Research
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• v.36 no.2
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• pp.199-208
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• 2014

Copepods are a major food source for marine fish larvae in nature. Many studies on copepods culture have been conducted to develop a new live food for the seedling production of marine fish larvae. But fish farmers still depend on rotifer and Artemia nauplii. This study was carried out to find suitable copepods as live food for the larvae in hatchery. Eight species of copepods (1 calanoid, 2 cyclpoid, 5 harpacticoid) that were fed Isochrysis galbana were examined in terms of the size of nauplii, fecundity, amino acids, and fatty acids contents. These species were divided into small (nauplii length 46-86 ${\mu}m$) and large (nauplii length 120-188 ${\mu}m$) size group. Nitokra spinipes in the small group and Tigriopus japonicus in the large group showed the highest fecundity with 151.1 and 139.6 nauplii production per gravid female, respectively. With regard to nutrients, essential amino acids were the highest with 21.2% in cyclopoid Paracyclopina nana in the small group and n-3 HUFA were the highest in calanoid Pseudodiaptomus inopinus (8.5 ${\mu}g/mg$) in the large group and P. nana (8.8 ${\mu}g/mg$). In terms of the size, fecundity, and nutritional value of copepods examined in this study, N. spinipes and P. nana seem to be suitable copepod species to develop as a new live food for small mouth fish larvae.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.323-332
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• 2011

To find seasonally optimal microalgae for mass culture of the rotifer Brachionus plicatilis, the growth rates of 12 microalgal species (two marine Chlorella spp., five marine Nannochloris spp., two marine Nannochloropsis spp., one estuarine Nannochloropsis sp., and two estuarine Chlorella spp.) were compared at $25^{\circ}C$ at 15 psu and 30 psu. Among these, six species showing high growth rates were chosen and examined again at high ($30^{\circ}C$ and $32^{\circ}C$) and low ($10^{\circ}C$) temperatures. Their amino and fatty acids and the dietary value of the rotifers that fed on each microalgal species were examined. Nannochloris sp. (KMMCC-119) and Chlorella vulgaris (KMMCC-120) showed the highest growth rates at temperatures over $30^{\circ}C$ and at $10^{\circ}C$, respectively. The growth rate of Nannochloris was higher than those of Chlorella and Nannochloropsis at high temperatures, but lower than those of the latter at low temperatures. The growth rate of rotifers fed on Nannochloropsis was highest and that of those fed on Chlorella was lowest. Levels of eicosapentaenoic acid and docosahexaenoic acid were highest in Nannochloropsis and lowest in Nannochloris. However, total amino acid content was highest in Nannochloris and lowest in Chlorella. In conclusion, Nannochloropsis sp. (KMMCC-33) was the best microalgal species for the mass culture of the rotifer. However, during high- or low-temperature seasons in which Nannochloropsis does not grow well, Nannochloris spp. (KMMCC-119, 395) and C. vulgaris (KMMCC-120) would adequately replace Nannochloropsis sp. (KMMCC-33).