• Animal cells and systems
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• v.2 no.1
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• pp.21-26
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• 1998

Three species of Poecilosclerid sponge (class Demospongiae, subclass Ceractinomorpha) are newly described from the waters around Cheju Island Keomun Island and Keoje Island. They are Antho (Plocamia) bakusi, Clathria (clathria) koreana and Oxymycale rhoi.

• Water for future
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• v.29 no.6
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• pp.28-36
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• 1996

• Environmental Analysis Health and Toxicology
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• v.17 no.4
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• pp.341-346
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• 2002

To investigate the residue of organophosphorus pesticides such as Monocrotophos［Dimethyl-1-methyl-2-methyl carbamoylvinylphosphate］and EPN［O-ethyl-O-4-nitrophenyl phenylphosphonothioate］in the coastal environment of Cheju island, samples of sea organism, water and sediment were collected at the Sackdaldong and Daepodong near the Jungmoon golf course in July and Aug. 1997. The qualified detection limit of mono-crotophos and EPN by GC -FPD were 0.024 ng/g and 0.020 ng/g in the sea organism, respectively Neither Monocrotophos nor EPN was detected in seaweed cava (Ecklonia cava), Agar (Gelidium amansii), turban sell (Batillus cornutus) and sea urchin (Anthocidaris Crassispina). They were not detected in seawater and sediment, either. These results showed that the coastal area near the Jungmoon golf course in the Cheju island was not polluted by the organophosphorus pesticides such as Monocrotophos and EPN.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.25 no.2
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• pp.61-69
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• 1989

Mackerel purse seine fishery operating in the sea area of Cheju and Tsushima is one of the most important fishery in Korean off shore fishery, which a fishing fleet are generally composed with one purse seiner, two light ships and three or four fish carriers. In this study, purse seiners are classified in to four classes in term of their gross tonnage : A class(80-100tons), B class(100-120tons), C class(130-140tons), and D class(140-150tons). Operating sea area are divided into five sectors including east and west sea area of Tsushima Island, coastal sea area of Cheju Island and south and west sea area of Cheju Island. The performance of the purse seiner, the fishing efficiency, the dimension of fishing gear and variation of CPUE in each operating sea area are summarized as follows: 1. The relationship between a gross tonnage x and net area of purse seine y of a purse seiner can be expressed as : y=538.8x+99657.3 2. The index of seasonal variation of CPUE from May to October is lower than the standard value, whereas index from November to April is higher. 3. The power factor of fishing efficiency by classes of boat-size shows significant differences with 1% level in each operating sea area. 4. The net efficiency of purse seiner by classes of boat-sea shows that B and C classes are higher than A and D classes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.6
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• pp.417-424
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• 1990

Effect of physical processes on the surface distributions of chlorophyll-a and nutrients was investigated in the southern sea of Korea during summer season. The northwestern area of Cheju Island had higher concentrations of the chlorophyll-a and nutrients than its southeastern area. A nutrient-rich patch was observed in the western area of Cheju Island and the northern area of $34^{\circ}N$ respectively. It seems that the patch in the western area of Cheju Island is formed by horizontal extension of the low-saline Coastal Water of China Contiental(CWCC), while the patch in the northern area of $34^{\circ}N$ by vertical mixing. Also, the high chlorophyll-a in the vicinity of Cheju Island appears to be ascribed to sufficient supply of nutrient from bottom water by coastal upwelling.

• Journal of Environmental Science International
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• v.7 no.6
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• pp.845-851
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• 1998

In order to manage the water quality from the flowing streams in Cheju Island, the characteristics of water quality was investigated from August, 1996 to May, 1997 and the pollutant loadings for future were estimated from the watershed at each stream. Comparing the mean concentrations of each water quality with the criterion of water quality in river, it was under I class except for Changgo Stream, for DO, under I class at the whole station for SS and under II class for BOD. As the pollutant loadings at each stream in 2020 is compared with those in 1996, the estimated results are as follows : 1) for BOD, 59% at Donghong Stream, 24% at Yeonoe Stream, 44% at Ohngpo Stream and 57% at Changgo Stream. 2) for T-N, 91% at Donghong Stream, 76% at Yeonoe Stream, 63% at Ohngpo Stream and 89% at Changgo Stream. 3) for T-P, 69% at Donghong Stream, 42% at Yeonoe Stream, 45% at Ohngpo Stream and 73% at Changgo Stream. The point source loadings discharged through combined sewer could be treated at sewage treatment plant. However, the expected slow decreasing rate of BOD, T-N, and T-P loadings is due to the part of untreated nonpoint source loadings. Nonpoint source loading overflow typically occurs when the flow of stormwater combined with sewage exceeds the capacity of the interceptor sewers. Since most of the sewers used in Cheju Island are the combined sewers, the combined overflow sewage is bypassed into the receiving water area after a rainstorm. Therefore, a means to control nonpoint source loadings should be considered for the river and marine water quality management.

• Korean Journal of Pharmacognosy
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• v.26 no.2
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• pp.116-121
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• 1995

To seek for a stable supply source of taxol as an anticancer agent urgently needed for the treatment of ovarian cancer, the concentrations of taxol and cephalomannine in bark and needles of 37 yew (Taxus cuspidata S. et Z.) trees grown in 6 locations of Cheju Island were analyzed by using HPLC. A considerable variation in the content was observed in plant part and the location. The average taxol content in the needles ($220.3{\;}{\pm}{\;}56{\;}{\mu}g$ per g dry wt) was ca. 4 times hgher than that in the bark, whereas the content of cephalomannine in the needles $(353{\;}{\pm}{\;}141{\;}{\mu}g)$ was ca. 5 times higher than that in the bark. Particularly, even within Cheju Island, needles from trees grown near the coast including Sogwipo area contained much higher taxol contents than needles from trees grown at mountain locations, indicating that taxane level is affected by environmental effects. Taxol in the needles was confirmed by electrospray mass spectrometry. These results suggest that the needles of yew trees growing in Cheju Island may provide a renewable source for taxol.

• The Korean Journal of Ecology
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• v.26 no.4
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• pp.209-214
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• 2003

In order to clarify the successional trend and its characteristics of plant community in abandoned field in Cheju Island, we investigated the seral changes of vegetation height, coverage, growth form, species richness, diversity and dominance index along with the time lapse, and then compared with those of mainland researches. And in order to seek the overall trend of vegetation changes, we used cluster, TWINSPAN and PCA ordination techniques. The succession was characterized by the lower species number, lower vegetation height, longer period of herb dominant and later invasion of tree species. These results may come from that ecological traits of Cheju Island itself, and ecosystem fragmented influences that block a seed (propagule) transport. Sere of the dominant species was shown as follows: Mazus japonicus(0.5∼1 years)→Conyza sumatrensis (2 years)→Artemisia princeps var. orientalis(4 years)→Artemisia princeps var. orientalis, indigofera pseudotinctoria(5 years)→Rosa multiflora, Miscanthus sinensis, etc.(8 years)→Miscanthus sinensis(12 years)→Boehmeria nivea, Pueraria thunbergiana etc.(15 years)→Mallotus japonicus(20 years)→Litsea japonica, Machilus thunbergii (20 years<). Abandoned fields were classified into three groups according to time lapse; earlier stage(0∼1 years), middle stage(2∼8 years) and later stage(8∼20 years).

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.198.1-198
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• 2005

• Proceedings of the Malacological Society of Korea Conference
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• 2003.11a
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• pp.9-9
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• 2003