• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.214-215
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• 2001

한국 남서해역의 끝단에 위치하는 마로해는 진도와 해남반도 사이에 위치하며 매우 빠른 유속과 다양한 수괴의 영향을 복잡한 해양환경 특성을 나타내는 해역이다(Rho and Pang; 1995; Yoon, 1998, 2000). 또한 연안수의 풍부한 영양염류 공급과 원활한 해수 소통으로 인하여 오래 전부터 김을 비롯한 해조류 양식이 성행하는 곳이기도 한다. 그러나, 이와 같은 다양한 해양환경특성과 해역을 이용하고 있음에도 불구하고 현재 과학적으로 수행된 연구조사는 전무한 실정이기도 하다. (중략)

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.124.2-124.2
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• 2010

Generally, a coolant of the nuclear power plant is manufactured by electrolyzing the sea water near the plant for making the sodium hypochlorite(NaOCl), which is used for sterilizing the bacteria and the shellfishes sticking to the drains or the pumps at the outlet of the cooling system due to $8-10^{\circ}C$ warmer temperature than the inlet sea water. During manufacturing the sodium hypochlorite, the hydrogen with the high purity is also produced at the anode side of the electrolyzer. This paper describes a novel power plant system combined with the polymer electrolyte membrane(PEM) fuel cell, the wasted hydrogen from the sea water electrolyzer and the wasted heat of the nuclear power plant. The present status over the exhausted hydrogen at twenty nuclear power plants in Korea was investigated in this study, from which an available power generation is estimated. Furthermore, the economic feasibility of the PEM fuel cell power plant is also evaluated by a current regulations over the power production and exchange using a renewable energy shown in Korea Power Exchange(KRX).

• Journal of Aquaculture
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• v.3 no.1
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• pp.89-125
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• 1990

In order to improve top shell seed production techniques spawning and larvae rearing were done in rearing tanks. Growth of young top shell in the nursing ground were also investigated. For induced spawning, top shells were maintained in still water during night time. Then they were treated with ultra violet iradiated sea water after dried up in air for 60 minutes. Spawning rate were 10 to $39.77\%$. It was found that young top shells moved in the growing grounds from nursing grounds when they reached approximately 30-40mm in shell heignt. Among main food algae for top shell in the natural growing grounds, sea mustard were melted away during June. Therefore, presence of another food algae such as Ecklonia cava or Sargassum spp. seems to be the main limiting factor for survival of top shell during summer. The tolerance of top shells ranging from 30mm to 60mm to low density of seawater for were tested at the temperature between 29.5 and $31.4^{\circ}C$. Hundred percent mortality occoured in 20, 55 and 90 hours after first stocking at the specific gravity of 1.010, 1.015, and 1.020, respectively.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.87-97
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• 2023

In this study, we examined the effects of a large wildfire in the coastal area of Uljin-gun. The analysis of water quality and the dominant species, species composition, and community structure of marine algal was conducted quarterly in 2022 at Nagok (F-1), Hujeong (F-2), Bongpyeong (F-3), and Gongse Port (F-C) in Uljin-gun. As a result of water quality analysis, the pH, a factor of wildfire impact was 8.07~8.30 and 8.12~8.48 in surface and bottom layers, respectively, which are normal values in coastal waters of the East Sea, suggesting no direct impact from wildfires. By marine algal species composition, the coastal areas show the following order: Rhodophyta (58.1%) > Ochrophyta (25.8%) > Chlorophyta (14.5%) > Magnoliophyta (1.6%). By season, Undaria pinnatifida was the most dominant at Nagok and Hujeong in March and June, which in September and November, Gelidium elegans and Lithophyllum sp. were the most dominant in Bongpyeong and Gongse Port, respectively. In the cluster analysis, the stations were divided into two groups according to presence and absence of specific marine algal by season. The dominant species were U. pinnatifida, G. elegans and D. divaricata in group A, and Lithophyllum sp. was mainly present in group B. Thus, the species composition and group structure reflected the normal seasonal change pattern with water temperature variation and showed little significant difference from the control site, suggesting no direct effects of the wildfire on algae distribution in Uljin.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.464-476
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• 2022

In recent years, macroalgal bloom occurs frequently in coastal oceans worldwide. It might be attributed to accelerating climate change. "Green tide" events caused by proliferation of green macroalgae (Ulva spp.) not only damage the local economy, but also harm coastal environments. These nuisance events have become common across several coastal regions of continents. In Korea, green tide incidences are readily seen throughout the year along the coastlines of Jeju Island, particularly the northeastern coast, since the 2000s. Ulva species are notorious to be difficult for morphology-based species identification due to their high degrees of phenotypic plasticity. In this study, to investigate temporal variation in Ulva community structure on Jeju Island between 2015 and 2020, chloroplast barcode tufA gene was sequenced and phylogenetically analyzed for 152 specimens from 24 sites. We found that Ulva ohnoi and Ulva pertusa known to be originated from subtropical regions were the most predominant all year round, suggesting that these two species contributed the most to local green tides in this region. While U. pertusa was relatively stable in frequency during 2015 to 2020, U. ohnoi increased 16% in frequency in 2020 (36.84%), which might be associated with rising sea surface temperature from which U. ohnoi could benefit. Two species (Ulva flexuosa, Ulva procera) of origins of Europe should be continuously monitored. The findings of this study provide valuable information and molecular genetic data of genus Ulva occurring in southern coasts of Korea, which will help mitigate negative influences of green tide events on Korea coast.