• Journal of Species Research
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• v.5 no.3
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• pp.551-565
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• 2016

This study aims to clarify the diversity of bryozoans which were collected from Seogwipo waters in Jeju Island, Korea. A total of 78 species has been reported from Seogwipo waters so far. In the present study, 63 species were found from nine sites of Seogwipo waters from 2008 to 2012, including six newly added species to the Korean bryozoan fauna and twelve species new to Seogwipo waters. As a result of this study, the bryozoans from Seogwipo waters were turned out to be 96 species, 64 genera, 42 families, three orders and two classes.

• Ocean and Polar Research
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• v.34 no.1
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• pp.65-71
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• 2012

Gambierdiscus toxicus, Adachi et. Fukuyo, is a benthic ciguatoxin-producing armored dinoflagellate, often attached to macroalgae. This organism is the primary causative agent of ciguatera fish poisoning which occurs in tropical and subtropical regions. However, regardless of the fact that the population of Gambierdiscus spp. has expanded to such temperate areas from sub-trophic and trophic areas, monitoring of G. toxicus has been lacking in the Korean coastal waters of temperate areas. This study was performed at the uninhabited Baekdo Islands off the southern coast of Korea and at Seopsom Island in the vicinity of Seogwipo, Jeju Province during April and May, 2011. Cell densities of Gambierdiscus spp. on macroalgae at Baekdo and Jeju Island ranged from zero to 56.4 cells $g^{-1}$. Maximum density was recorded on the brown alga Cladophora japonica at St. 3 of Jeju Island. In particular, the cell densities of Gambierdiscus spp. were influenced by the substrate characteristics of macroalgae. In the future, the continuous monitoring of toxic benthic dinoflagellate is necessary to predict and prevent ciguatera poisoning in Korean coastal waters.

• Animal Systematics, Evolution and Diversity
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• v.25 no.3
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• pp.255-259
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• 2009

The sessile ctenophores, Lyrocteis imperatoris Komai, 1941 were collected for the first time from Garinyeo, offshore Seogwipo of Jejudo Island by SCUBA diving on June 18, 2009. This species distributed in West North Pacific was newly recorded in Korean waters. Its embryos in various developmental stages were observed in the internal brood chamber.

• Development and Reproduction
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• v.25 no.3
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• pp.145-155
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• 2021

Reproductive cycle of the blue-striped angelfish, Chaetodontoplus septentrionalis were histologically investigated. Fish were monthly collected in the coastal waters of Munseom, Seogwipo, Jeju-Island from February to December 2018. The gonadosomatic index (GSI) increased from May and maintained high values in August. The reproductive cycle of female fish can be classified by the characteristics observed during gonadal development as followed: growing stage (November to June), early mature stage (May to June), mature and spawning stage (June to September), and degenerative and recovery stage (September to December). In the male, testicular development period was similar to that of ovarian development period, but mature and spawning period was one month longer from June to October. Fecundity of mature female ranged from 4,601 to 22,840 and was correlated positively with total length and body weight. The histological analysis of gonadal development indicated that the C. septentrionalis was summer-spawning type and is considered a multiple spawner during spawning season.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.267-268
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• 2022

Jeju coastal waters are limited to high-risk areas due to the passage of international cruise ships, passenger ships, with a large number of people and fishing boats, or to the jeju port and the jeju civilian-military combined port and near by seas, so a VTS system will be established along jeju and seogwipo coast. There is no accurate standard for determining the number of people required by the maritime traffic control center. Therefore, this study calculated the required operating personnel for control seats on the coast of jeju and seogwipo by using VTS big data to efficiently calculate the workload of maritime traffic control. It is judged that this study can be used basic data for research that sets the standard for calculating the control workload.

• Journal of Species Research
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• v.6 no.spc
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• pp.54-57
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• 2017

A pagurid crab, Pagurus erythrogrammus is described and illustrated for the first time from Korean waters. It was collected by SCUBA diving in Seogwipo (Jejudo Island) on 30 May 2013. Its morphology is similar to those of known Korean species of the family Paguridae: Boninpagurus pilosipes, Pagurus nigrivittatus, and Pagurus quinquelineatus. This species, however, it is distinguished by having a developed rostrum, seven rows of spines on dorsal surface of the right palm in male, a row of spines on the medial surface of the dactylus of the third pereopod, 12 long ventral spines of dactylus of the third pereopod, six small spines on the concaved distal margin of telson, and three reddish brown lines on lateral surfaces of propodi of the second and third pereopods.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.213-219
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• 1980

Morphological characteristics of the topshell, Turbo cornutus Solander were studied on the basis of shell growth and fatness from April 1978 to October 1979. The Sampled areas were coastal waters of Jeju City, Seongsanpo, Moseulpo and Seogwipo in Jeju. The average shell length of the topshell from Jeju City area was smaller than those of the other three areas, and also the spine number of the 1st row on the shell from Jeju City area was fewer than the others. Sex ratios from each areas represented about 1:1. The relationship between shell length and shell breadth showed regression line and the value of slope for the specimen from Seongsanpo was the lowest. The relationship between shell length and total weight showed exponential curve, and the value was the highest in the specimens from Moseulpo. The value of slope on the relationship between total weight and meat weight was the highest in those from Moseulpo and the lowest from Jeju City. The regression line of relationship between total weight and meat freight in those if Jeju City area showed significant difference from those of the other areas.

• Journal of Aquaculture
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• v.1 no.1
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• pp.85-102
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• 1988

An experimental study on seedling production and wintering to develop pearl oyster, Pinctada fucata culture in Korea was carried out. from December 1986 to November 1988 in waters of Kori and of Seogwipo as wintering and of Eogu as culturing grounds. All pearl oysters as the sample were imported from Japan. The highest water temperature at Eogu was $23.6^{\circ}C$ in August and the lowest at Kori and Seogwipo were $13.2^{\circ}C$ and $14.0^{\circ}C$c in February, respectively, Phytoplankton was relatively plentiful but mortality of pearl oysters was $20.5\%$, which was twice at Seogwipo, due to high amount of suspended muds. It shows that Seogwipo is better wintering ground even though the amount of phytoplankton is lower than Kori. Average rates of pearl production after 6-months and 15-months period were $58.2\%$ and $48.3\%$ respecitively. Thickness of pearl layer and coating rate were also satisfactory. More than half of the pearls produced was so-called the pink-pearl, the best colour. About $10\%$ of them was the best quality. There were three peaks of D-shape larvae from July to September and it took about one month for D-shape larvae to become seed-shells. Settling was satisfactory and most of them settled at 1$\~$3 m layer and the best was 2 m-layer. Success of settling was supposed due to high water temperature and low precipitation than the normal year.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.305-315
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• 1983

A survey was carried out from July to December in 1979 and 1982 for the investigation of oceanographic conditions and phytoplankton in Seogwipo coastal area. Although a peculiar coastal sea water is formed by in flowing of fresh water, this is developed mainly in summer and disappeared or weakened in its strength after November. However, this coastal sea water covers only the surface while in mid and bottom layer open sea water is approached to the coast. Therefore, coastal and open sea water appears simultaneously in narrow sea area. Mean values of nutrient concentrates on surface layer during investigating period were $3.72{\sim}16.34{\mu}g-at/l$ in silicate, $1.98{\sim}5.53{\mu}g-at/l$ in nitrate and $0.34{\sim}0.90{\mu}g-at/l$ in phosphate. These showed slight differences among places but in general coastal side were lower than open sea side. Phosphates which is the lowest in concentrates among nutrients in Seogwipo coastal area shows almost similar value with Jinhae Bay but higher than open sea water around 10 mile south of Seogwipo. In general, seasonal changes of nutrients in investigating period shows a tendency of the lowest in October, increasing in November, and again slight decrease in December. As a phytoplankton fauna, 48 species, 1 variety and 2 breeds of Diatoms, 29 species, 3 varieties and 1 breed fo Dinoflagellates, and 1 species each of Chroococcus and Trichoceratium were found. Monthly predominant species are all neritic: Rhizosolenia sp. and Ceratium sp. in August, Chaetoceros sp., Ceratium sp. and Peridinium sp. in September, Astrionella sp. and Peridinium sp. in October, Astrionella sp., Navicula sp. and Chaetoceros sp. in November Among these, Rhizosolenia alata f. gracillima in August and Astrionella gracillima in November are remarkable predominant.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.3
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• pp.184-192
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• 1988

Anchovy, Engraulis Japonica were caught by scoop net with fishing lamp in the surrounding water of Cheju and Seogwipo, and their gathering depth, gathering effects, change of catch by the age of the moon and submarine illumination were investigated from May to August 1985. Fish finder (SR-385) and fishing lamp (1 Kw incandescent) were set up at one meter of starboard of scoop net and one meter ahead of the prow together with two meters above the water surface respectively. The submarine illumunation was measured at 2m interval to both vertical direction of 0~18m and horizontal direction of 0~12m form the standard point which is to be 0.1m depth right under the fishing lamp. The catch of anchovy by scoop net was almost $90\%$ of total amount during the early period and the late period in moon age while as low as $10\%$ only was cought during the middle period. The catching depth of anchovy shoals by scoop net with fishing lamp was approximately 2~5m and submarine illuminations were 20~42 Lux, 24~48 Lux in Cheju and Seogwipo respec lively. Submarine illumination which could be cought by scoop net with fishing lamp should be 7~12 times lighter than before gathering since the shoals swiming at 10~15m depth which is 1.7~7 Lux illumination made by 1 Kw. AC 100V incandescent lamp, a surface gathering lamp of 2m high above anchovy scoop net came up to 2~5m depth which is 20~42 Lux illumination. The catching depth of anchovy by scoop net was 2~3m and this could be increased to 4m even though the AC voltage was decreased from 100V to 80V at final fishing stage.