• ALGAE
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• 제34권4호
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• pp.253-266
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• 2019

Several species classified to the genus Ulva are primarily responsible for causing green tides all over the world. For almost two decades, green tides have been resulted in numerous ecological problems along the eastern coast of Jeju Island, Korea. In order to characterize the species of Ulva responsible for causing the massive blooms on Jeju Island, we conducted DNA barcoding of tufA and rbcL sequences on 183 specimens of Ulva from eight sites on Jeju Island. The concatenated analysis identified five bloom-forming species: U. australis, U. lactuca, U. laetevirens, U. ohnoi and a novel species, U. pseudo-ohnoi sp. nov. Among them, U. australis, U. lactuca, and U. laetevirens caused to the blooms coming mainly from the substratum. U. ohnoi and U. pseudo-ohnoi sp. nov. were causative the free-floating blooms. Four species, except U. australis, are characterized by marginal teeth. A novel species, U. pseudo-ohnoi sp. nov., is clearly diverged from the U. lactuca, U. laetevirens, and U. ohnoi clade in the concatenated maximum likelihood analysis. Accurate species delimitation will contribute to a management of massive Ulva blooms based on this more comprehensive knowledge.

• 한국환경복원기술학회지
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• 제15권6호
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• pp.53-59
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• 2012

This this study was conducted with the aim of doing experiment on the effect of water purification by using an artificially built plant island, which is one of the eco-techniques, and aquatic plants as a plan for the reuse of water for obtaining water resources, thereby analyzing the removed quantity, and applying the experimental results to the reuse of water. As a result of doing experiments, this study obtained a good measured value of BOD (biochemical oxygen demand) 4.7mg/L, and COD (chemical oxygen demand) 7.2mg/L below the heavy water standard of BOD 10mg/L and COD 20mg/L, respectively. The chromaticity showed 89.2% removal efficiency, but final treated wastewater was found to show chromaticity 58 degrees exceeding chromaticity 20 degrees which are the water quality standard of the reuse of water. The results revealed that T-N produced 27% removal efficiency on an average while T-P produced 38% removal efficiency on an average, showing that the removal effect of N & P wasn't big. According to the currently enforced "Water Quality Standard of Heavy Water by Use", the use of water for sprinkling and landscaping was found to be available. Accordingly, this study suggested a nature-friendly, economically-efficient, and eco-technological water treatment technique which will make it possible to overcome the limit of the existing physio-chemical water treatment technology, reduce the costs for maintenance and facilities, and also reduce the limit of space restraint for installation of facilities.

• 한국수산과학회지
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• 제32권3호
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• pp.338-344
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• 1999

Floating debris was recorded from a training ship, $\sharp$1 Kwanaksan, of Pukyong National University with about 10 knots speed at July 15th and 20th of 1997. The sampled area is the middle of southern sea of Korea, divided into 44 unit segments on survey routes. Debris fabrication materials were categorized with 6 items using the following; man-made or natural wood items, paper and cardboard, nylon netting and rope, styrofoam, plastics, floating metal and glass containers. All identified items within a 100 $\pm$ 2 m wide band were recorded but ignored if beyond this boundary. The results of distribution and transport of floating debris in the area are as follows: 1. The quantities of debris during the survey were distributed from $1.6\~369.7\;items/km^2$. The most obvious trend is the widespread distribution of all debris. The highest densities of all debris were discovered in the coastal waters of Namhae and Yokji island, and of about 50 km off from the southward of Yokji and about 74 km off from the eastward of Komun island. Especially many of small styrofoams within $\phi$20 cm were observed in these segments. 2. Styrofoams and plastics were composed of $83.5\%$ among all debris, next woods items, $9.8\%$. 3. The quantities, distribution shapes and composition of debris were varied as the observed duration and the natures of each items. 4. These phenomena are concluded that firstly they depend on the river discharges included debris due to precipitation falls, secondly inflow or dumping debris are drifting to the off-shore by Kuroshio currents present at their adjacent sea, But on the basis of the observed data it is difficult that source position, quantities and inflow items of debris are identified, and also the transport processes is pursue. further more surveys are continuously being investigated, and from this it is hoped that a much wider coverage can be achieved, perhaps on all sites of the Coast of Korea and contributed to the stationary area, finding of sources, removal method of debris and resistants of marine productivity.

• 한국수산과학회지
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• 제49권5호
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• pp.689-693
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• 2016

Sargassum golden tides occurred in Shinan-gun and Jeju Island, Korea, between January and May 2015. In Shinangun, 5,180 tons of Sargassum were removed from 3,339 ha of coastline, while 20,000 tons were removed from Jeju Island. The huge floating masses of seaweed caused damage to fisheries in Shinan-gun including abalone sea cage, Pyropia and Saccharina farms off the southwest coast of Korea. Drifting Sargassum also washed ashore on Jeju Island. The species of Sargassum in these golden tides was identified as S. horneri (Turner) C. Agardh, based on morphology and molecular data, and it appears to have originated from the East China Sea. This is the first report on Sargassum golden tides causing damage to fisheries in Korea.

• 수산해양교육연구
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• 제17권1호
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• pp.58-66
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• 2005

Floating debris was observed using a training ship, KAYA, of Pukyong National University with cruising speed of about 10-12 knot during July 12~25, 2003. The area sampled was the East Sea enclosed by 3 nations, namely, Korea, Japan and Russia, and was divided into 68 unit segments on survey routes [Fig. 1]. Debris fabrication materials were categorized with 6 items, e.g., man-made or natural wood items, paper and cardboard, nylon rope, styrofoam, vinyl and plastic, floating metal and glass containers. All identified items within $100{\pm}10 m$ wide band were recorded but ignored if beyond this boundary. The results of this study are as follows: 1. The average numbers of debris per unit area, $1km^2$, were found as 16.3 pieces (items) in the sea. 2. The highest densities of numbers, $32.3pieces/km^2$, were discovered in vicinity of the Oki strait of Japan, area of 'NEK' in Fig. 1. 3. Especially, styrofoam item only was composed to 63.6% of all in the sea of 'SD', located in the southern part of Dokdo Island, Korea. The item seems to be derive from the Southern Sea of Korea. 4. Therefore, comparing the distribution of debris numbers (the results of above 2 and 3) with flow patterns of Kuroshio currents, it was shown that their relation was good agree each other. Further more surveys are being conducted and a much wider coverage can be achieved with other countries, then it can be obtained that the East Sea is polluted to some extent, where is the origin of debris, and the finding of floating routes and stationary sea.

• Structural Engineering and Mechanics
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• 제88권4호
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• pp.323-334
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• 2023

The submerged floating tunnel (SFT) infrastructure has been regarded as an emerging technology that efficiently and safely connects land and islands. The SFT route problem is an essential part of the SFT planning and design phase, with significant impacts on the surrounding environment. This study aims to develop an optimization model considering transportation and structure factors. The SFT routing problem was optimized based on two objective functions, i.e., minimizing total travel time and cumulative strains, using NSGA-II. The proposed model was applied to the section from Mokpo to Jeju Island using road network and wave observation data. As a result of the proposed model, a Pareto optimum curve was obtained, showing a negative correlation between the total travel time and cumulative strain. Based on the inflection points on the Pareto optimum curve, four optimal SFT routes were selected and compared to identify the pros and cons. The travel time savings of the four selected alternatives were estimated to range from 9.9% to 10.5% compared to the non-implemented scenario. In terms of demand, there was a substantial shift in the number of travel and freight trips from airways to railways and roadways. Cumulative strain, calculated based on SFT distance, support structure, and wave energy, was found to be low when the route passed through small islands. The proposed model helps decision-making in the planning and design phases of SFT projects, ultimately contributing to the progress of a safe, efficient, and sustainable SFT infrastructure.

• 한국환경생태학회지
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• 제28권5호
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• pp.559-565
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• 2014

2013년 5월부터 6월까지 소양호에 설치된 인공식물섬에서 출현 어류와 어란 부착을 조사하였다. 잠수하여 수중 관찰한 결과 청평리에서는 피라미(Zacco platypus) 5.2%, 쏘가리(Siniperca scherzeri) 1.0%, 블루길(Lepomis macrochirus) 90.8%, 배스(Micropterus salmoides) 3.0% 등이 출현하였다. 웅진리에서는 잉어(Cyprinus carpio) 0.4%, 피라미 54.6%, 블루길 20.3%, 배스 24.7%등 이었다. 시설물 인접수역에서는 총 7과 22종이 출현하였다. 이 중 국외 도입종에 속하는 어종은 떡붕어(Carassius cuvieri), 블루길, 배스 등 이었고 피라미 30.4%, 블루길 18.9%, 끄리(Opsariichthys uncirostris amurensis) 15.4%, 누치(Hemibarbus labeo) 9.3% 등의 순으로 개체수가 풍부하였다. 부착한 어란은 $1m^2$당 청평리에서는 800개, 웅진리에서 1,100개 이었으며 시설물 전체에서는 청평리에서 708,800개, 웅진리에서 974,500개로 추정되었다. 어란은 붕어(Carassius auratus) 504,920개(청평리 212,640개, 웅진리 292,280개)와 잉어 1,178,380개(청평리 496,160개, 웅진리 682,220개) 이었다. 부착한 수정란이 폐사하지 않고 부화한 개체는 붕어 350,505개(청평리 102,067개, 웅진리 248,438개)와 잉어 811,222개(청평리 238,157개, 웅진리 573,065개) 이었다.

• 생태와환경
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• 제41권spc호
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• pp.93-98
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• 2008

인공식물섬의 BOD, SS, T-N, T-P제거효율과 조류의 성장억제 능력을 분석하였으며 조류제어효과에 있어서 미생물보유활성화, 식물의 흡수효과에 대한 각각의 효과성을 판단하기 위해 구성요소별 장치를 구성하여 실험하였다. 구성요소별 장치는 (1) Blank Test, (2) 인공식물섬(VAFI) $0.25m^2$, (3) 식물을 식재 하지 않은 인공식물섬(AFI) $0.25m^2$, (4) 인공식물섬을 수면위로 부유시키기 위한 부력재 $0.25m^2$, (5) Media (부력재 $0.25m^2$에 50cm 길이로 Media를 4줄 부착)이다. BOD제거는 VAFI, AFI, 부력재, Media에서 각각 82.7, 80.8, 45.2, 59.6%로 나타났다. T-N제거는 VAFI, AFI, Media에서 각각 51.2, 31.7, 25.1%로 나타났다. T-P제거는 VAFI, AFI, 부력재, Media에서 각각 23.3, 16.7, 10.0, 13.3%로 나타났다. 엽록소-${alpha}$는 VAFI에서 97.9%가 제거되었다. VAFI의 구성 요소별 제거율은 차광효과 35.1%,미생물의 복합작용에 의한 효과 61%, 식물과 뿌리에 의한 효과 1.8%인 것으로 나타났다.

• 한국해양학회지:바다
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• 제11권4호
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• pp.165-171
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• 2006

본 연구는 비교적 저농도로 오염된 하천수를 대상으로 phytoremediation 기법으로 정화방안을 제시하고자 수행되었다. 온실에 식물 반응조를 설치하여 해바라기 일종인 Heilianthus annuus의 성장에 따라 영양염의 처리량을 산정하였다. 또한 현장 적용성을 검토하기 위하여 H. annuus을 식재한 인공부도(artificial floating island)를 관개수로에 설치하여 식물의 질소, 탄소 및 수소 함유량 증가를 확인하였다. 실험결과 7월부터 9월에 이르기까지 유입수 용존 무기질소(DIN)의 농도를 $28.5\sim199.2mg/l$, 유입수 용존무기인(DIP)의 농도를 $13.3\sim25.4mg/l$ 까지 변동 시켰을 때, 농업용수 기준보다 매우 높은 고농도임에도, 식물체의 성장장해는 나타나지 않았다. 이때 DIN 제거율은 평균 3일의 체류시간에서 $81.7\sim98.6%$였으며, DIP 제거율은 $81.9\sim98.4%$로 나타났다. 또한 효율적인 처리기간은 48시간으로 확인되었다. 인공부도에 식재한 H. annuus의 질소, 탄소 및 수소의 함유량을 보면 질소의 경우 줄기에서 $3.2\sim7.8%$, 뿌리에서 $3.0\sim6.3%$를 보였다. 탄소는 줄기에서 $40.1\sim57.7%$, 뿌리에서 $43.4\sim53.8%$의 함유량을 보였다.

• 한국습지학회지
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• 제9권1호
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• pp.31-46
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• 2007

In this paper, the nature-based tourism is described as one of the tools to achieve sustainable development in small islands. The study was carried out at Ayer, Bidadari and Onrust Islands of Kepulauan Seribu chains at Jakarta Bay, Indonesia. While the historical records show that previous uses of such islands have started at sixteen century, tourism uses was started at the beginning of 1970s. Among nature-based tourism destination in Kepulauan Seribu chains, these islands are the famous destinations and received a lot of tourists. Tourism growth at these islands has stimulated development of numerous tourism facilities and infrastructure to meet visitor satisfaction. It is observed in this study that island's site-plan destination design has contributed to the successful and sustainability of tourism in small island. The key success lies on the successful integration and implementation of three substantial perspectives into practices, namely economic, ecosystem and social perspectives. First, in order to enhance economic benefits, a site-plan design allowing floating cottages establishment to extent room availability, to build strong images as tropical paradise islands, and to enhance tourist satisfaction with the objectives of improving income and sustaining tourist loyalty to the destination. This design is also reducing land risk from tourism impact and it becomes the significant key of second perspective, the ecosystem perspective. Moreover, the ecosystem perspective has been implemented through native vegetation preservation that led island's wildlife conservation and became potential tourism attraction. The design also develops effective mechanism to manage and regulate visitor flows by establishing visitor track corridors. In implementation, such corridor plays an important role to reduce tourist density in single places and therefore become instrument to reduce severe visitor impact to wildlife, vegetation and heritages of islands. Third, the social aspect of development allowing heritages to conserve and furthermore serve numerous benefits for education, socio-political, culture, and historical studies. Through this study, it is clear that the success of these islands to continuous tourism growth lies on the island's vision to integrate economic, ecosystem and social perspectives on tourism development.