• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.4
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• pp.157-162
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• 1987

The basic experiments on the plastic sea eel pots used in fishing were carried out in order to investigate the elasticity of the funnel ribs, hydrodynamic resistance, sinking time and diffusion of the bait from June to October, 1987. The elasticity of the bamboo funnel ribs was higher than that of the polypropylene ribs up to the load 150g. The hydrodynamic resistance R (kg) of the pots towing to the head direction horizontally in relation to towing velocity V (m/sec) was expressed as following formula; R=0.36V super(2.01) and coefficient of drag C sub(D) was 0.52. The sinking times of the covered pots by tape fully or partially were late 1-2 second than the typical pots within the water depth 7.5m. The diffusion tendency through the covered pots using dye and sardine extracts solution was concentrated to the entrance more than the typical pots. However, fishing efficiency as number and weight of fish per pots for nine times fishing operation was revealed no difference between the covered pots and the typical pots.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.4
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• pp.215-220
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• 1974

The sand-eel, Ammedytes Personatus is a commercially important fish abounantly found in west and east coast of Korea. Samples were collected from the Baegryeong Island (Yellow Sea), Geoje Island(southern coast) and Jumunjin (East Sea) from May 1973 to December 1974. In this paper the author dealt with some biological point of the fish, especially the relationship between total length ang body weight, and the major spawning season and sex ratio. 1. The major spawning season was confined to the end of November and the end of December at Jumunjin. 2. The sex ratio (male/female) is 0.75 before the main spawning season and increases up to 1.36 after spawning at Jumunjin in 1974. 3. The relationship between the total length (L) and body weight (In were represented as follows: $W=0.0001906L^{3.1998319}$ for the sample from Baegryeong Is. $W=0.0003419L^{3.0213438}$ for the sample from Geoje Is. $W=0.0002655L^{3.1408629}$ for the sample from Jumunjin.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.1
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• pp.45-50
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• 1990

The basic investigation of the sea eel pots fisheries by questionnarie observation and dimension of the pots by fishing operation were carried out in order to develop for mechanical hauling system with 20~50 gross tonnage fishing boats from June to December, 1988. Number and weight of fish per pot between smaller diameter 11cm and larger 13cm of the pot have no significance so that the drag of the smaller pots can be decreased about 20% than the larger pots. The operating time by two men from opening to closing with screwing lock entrance was slightly faster than that by three men with knotting entrance even though the losses with two kinds of entrances while fishing operation were about the same. It was very reasonable that stone and lead sinker on the main line were substitute for two or three lead core P.P rope to make it smooth surface of the main line for mechanization of the continuous fishing operation.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.4
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• pp.512-518
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• 1997

This study was performed to determine the amount of aluminum, which is one of the factors of Alzheimer's disease, In some fishes caught from some areas of the west coast in Korea. The 46 aquatic products were composed of fishes, molluscs, and salt-fermented products (jeot-gal). The 24 fishes were Hickory shad, Gobies, Pomfref, Atkafish, Flounder, Jambeng-ie Monk fish, Yellow hair tail, Mackerel, Bartailed flathead, Alaska pollack, Brown croaker, Eel, Fine-spotted flounder, Black spotted grouper, Sea-eel, Pacific saury, Areliscus honaleus, Small boil-dried anchovy, Croaker, Hair tail, Sea bream genuine, Motleystrip rainbowfish, and Bastard halibut. The 15 Molluscs were Whip-arm octopus, Sea arrow, Common squid, Han chi, Cuttle fish, Turban shell, Pond snail, Orient calm, Surf calm, Butter calm, Crib shell, Oyster, Egg cockle, Little neck calm, and Arkshell. The 7 salt-fermented products were salt-fermented Shrimp, Little neck, Oyster, Shad, Gonjeng-ie, Hqangsegi, and Squid. All of them were ashed with 5$m\ell$ HNO$_3$ and then with 10$m\ell$ ternary solution (HNO$_3$ : H$_2$SO$_4$ : HClO$_4$= 10 : 1 : 4). After ashing of the samples, the aluminum amount were measured by ICP. The aluminum amount of molluscs was significantly higher than that of fishes and salt-fermented products(p＜0.01). The aluminum amount of Orient calm and Healak in molluscs were 827.70, 812.55ppm, respectively, which were the most amounts compared nth that of the other samples. But the aluminum amounts of Bartailed flathead and Sea bream, genuine In fishes were 0.98, 0.97ppm, respectively, which were the least amounts compared with that of other samples. This study was limited within 46 aquatic samples, therefore I hope there will be wider efforts to determine about auminum amount in broade range of aquatic foods for the prevention of Alzheimer's disease.

• Parasites, Hosts and Diseases
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• v.53 no.3
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• pp.349-353
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• 2015

Anisakis simplex sensu stricto (s.s.), Anisakis pegreffii, Anisakis berlandi (=A. simplex sp. C), and Anisakis typica are the 4 major species of Anisakis type I larvae. In the Republic of Korea (Korea), A. pegreffii, A. berlandi, and A. typica larvae in fish hosts has seldom been documented. In this study, molecular analysis was performed on Anisakis larvae from the sea eels (Astroconger myriaster), the major source of human anisakiasis in Korea, collected from Tongyeong City, a southern coastal area of Korea. All 20 sea eels examined were infected with Anisakis type I larvae (160 larvae; 8 per fish). Their species were analyzed using PCR-RFLP patterns and nucleotide sequences of internal transcribed spacers (ITS1, 5.8 subunit gene, and ITS2) and mitochondrial cytochrome c oxidase 2 (cox2). Most (86.8%; 112/129) of the Anisakis type I larvae were A. pegreffii, and 7.8% (10/129) were A. typica. The remaining 5.4% (7/129) was not identified. Thus, A. pegreffii is the major species of anisakid larvae in sea eels of the southern coast of Korea.

• The Journal of the Acoustical Society of Korea
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• v.20 no.2E
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• pp.30-45
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• 2001

This study considers the environmental factors affecting propagation loss and sonar performance in the continental regions of the East Coast Sea of Korea. Water mass distributions appear to change dramatically in a few weeks. Simple calculation with the case when the NKCW (North Korean Cold Water) develops shows that the difference in propagation loss may reach in the worst up to 10dB over range 5km. Another factor, an eddy, has typical dimensions of 100-200km in diameter and 150-200m in thickness. Employing a typical eddy and assuming frequency to be 100Hz, its effects on propagation loss appear to make lower the normal formation of convergence zones with which sonars are possible to detect long-range targets. The change of convergence zones may result in 10dB difference in received signals in a given depth. Thermal fronts also appear to be critical restrictions to operating sonars in shallow waters. Assuming frequency to be 200Hz, thermal fronts can make 10dB difference in propagation loss between with and without them over range 20km. An observation made in one site in the East Coast Sea of Korea reveals that internal waves may appear in near-inertial period and their spectra may exist in periods 2-17min. A simulation employing simple internal wave packets gives that they break convergence zones on the bottom, causing the performance degradation of FOM as much as 4dB in frequency 1kHz. An acoustic experiment, using fixed source and receiver at the same site, shows that the received signals fluctuate tremendously with time reaching up to 6.5dB in frequencies 1kHz or less. Ambient noises give negative effects directly on sonar performance. Measurements at some sites in the East Coast Sea of Korea suggest that the noise levels greatly fluctuate with time, for example noon and early morning, mainly due to ship traffics. The average difference in a day may reach 10dB in frequency 200Hz. Another experiment using an array of hydrophones gives that the spectrum levels of ambient noises are highly directional, their difference being as large as 10dB with vertical or horizontal angles. This fact strongly implies that we should obtain in-situ information of noise levels to estimate reasonable sonar performance. As one of non-stationary noise sources, an eel may give serious problems to sonar operation on or under the sea bottoms. Observed eel noises in a pier of water depth 14m appear to have duration time of about 0.4 seconds and frequency ranges of 0.2-2.8kHz. The 'song'of an eel increases ambient noise levels to average 2.16dB in the frequencies concerned, being large enough to degrade detection performance of the sonars on or below sediments. An experiment using hydrophones in water and sediment gives that sensitivity drops of 3-4dB are expected for the hydrophones laid in sediment at frequencies of 0.5-1.5kHz. The SNR difference between in water and in sediment, however, shows large fluctuations rather than stable patterns with the source-receiver ranges.

• Journal of Fisheries and Marine Sciences Education
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• v.17 no.1
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• pp.132-143
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• 2005

In order to investigate the seasonal variation of watermass and fishery creatures in the adjacent sea of Naro Island, an oceanographic observation was carried out seasonally on the fishing grounds, and the sales performance data of the fisheries cooperative's joint market of Naro Island was examined by using a principal component analysis. The temperature and salinity ranged from 8.1 $^{\circ}C$ to 13.7 $^{\circ}C$ and from 33.1 psu to 34.3 psu in spring, from 14.5 $^{\circ}C$ to 24.2 $^{\circ}C$ and from 30.5 psu to 34.1 psu in summer, from 14.8 $^{\circ}C$ to 18.6 $^{\circ}C$ and from 30.1 psu to 34.0 psu in autumn, and from 4.3 $^{\circ}C$ to 10.1 $^{\circ}C$ and from 33.1 psu to 34.9 psu in winter, respectively. In winter and spring, the offshore water spread out to all sea areas of all water layers. In summer, the mixed waters covered the entire sea surface whereas the mixed water and offshore water covered the bottom. In autumn, the coastal water and mixed water appeared on the surface, but the mixed water was distributed widely on the bottom and the offshore water began to appear in the open sea. For two years from 2002 to 2003, 58 fishery creature species in total were sold in the fisheries cooperative's joint market of Naro Island. In general, the total of 50% fish were sold, and crustacea and mollusc by each 25%. Medium shrimp, whiparm octopus, blue crab, and octopus predominated. A number of species and biomass of fishery creatures were sold mostly in April and May, while they were sold the least in January and February. The seasonal sales results showed that mullet, angler, short necked clam, large shrimp, and webfoot octopus were sold mainly in spring, tonguefish, flathead, pomfret, glass eel, blue crab, whiparm octopus, and squid were sold mainly in summer, and octopus, medium shrimp, and spanish mackerel were sold mainly in autumn.

• Journal of Fisheries and Marine Sciences Education
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• v.18 no.3
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• pp.236-243
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• 2006

A series of surveys are performed to evaluate the abundance, composition and distribution of marine debris on the sea bed around the Busan port. In order to set up a master plan for the marine environmental pollution the relevant maritime authority must understand how many and w㏊t kinds of marine litters are distributed on the sea bed. At first we planed to survey areas divided regularly according to the coast line but there were many sea going vessels and fishing boats. So we selected and surveyed the around area where there were no sea going vessels or fishing boats.The obtained results are as follows: 1. The mean values of litters in number and weight are 5.8 pieces/㏊. and 3.5㎏/㏊. respectively. 2. The highest density in terms of number are vinyl and plastic item, and in weight are fishing gear and ship articles. 3. The nearer to the shore we surveyed the more we collected in terms of the density of marine litters in number and in weight per hectare. 4. Eel pot, oiled waste, rope, others, other pot and net of fishing gear litters in number were 59.9, 22.7, 7.9, 4.5, 3.1 and 1.9% respectively. 5. There is no relationship between the amount of fish caught and the amount of marine debris.

• Journal of Fisheries and Marine Sciences Education
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• v.11 no.1
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• pp.24-42
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• 1999

I have studied historical transition process of fisheries industries, fisheries Institute in abreast of developing fisheries industries of west coast of Korea since 1910 year with regard to the Gogunsan Is. The results were summarized as follows. In 1910 year, fishery industry has been carried out shifting fishing gear e.g set-net in shallow waters, small stow net, small seine net adapting to the tophorgrapical feature, shape of coast, oceanic condition, however, the fishing gear and fishing method were undeveloped, so that, Japanese fishermen had been exploited fisheries resources penetrating the fishing ground. Most important species were lot of captured croaker, cod, spanish mackeral, sea abream, herring in coastal sea. nowaday, squid, anchovy, shrimp, crab, pompret were much captured. The species were captured in 18 century were not captured. It is rarely than that period. Fishereis aquatic culture had been not farmed till 1960 year, but sea laver, shrimp, crab, had been breeded 1970 year also, the fresh water fish e.g. eel, cat-fish had been breeded activately. The fisheries processing industry were composed of salt. icing, dry, method. the salted fish industry had been prevailed at Gangyng, Kwangchon, Kunsan, Julpo comparatively. The fisheries institute had been established at Kunsan at first, but institute established in other region had been abolished in a short time. This phenomenon was related with development of fisheries resources. The western coast fisheries industries had been wasted of decreasing of fisheries resources, variation of environment. Accordingly, the study of preserving the marine resources. educated man power who engaged in fisheries field have to accomplish. Sea was dying with reason of loss of mud in west coast factory waste, waste of life the increase of accident of sea polluted, each illegal fishing industry physical and chemical reason etc. in this respect, Kusan maritime college, fisheries developing agency, institute have to take important role for developing fishing industry.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.3
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• pp.202-208
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• 2002

Test fishing was carried out utilizing a coastal pot-fishing boat from IS March to 7 April 2002 and the results obtained are summarized as follows ; 1. Mean catches(Number of sea eels) according to the soak time of 3 hours, 6 hours and 12 hours were 44.6, 60.0 and 83.3, and CPUE(Number of catch / 10pots·hour) were 2.5, 1.7 and 1.1 respectively 2. Catch difference between over 24 hours and 48 hours was 11.3% and 3.3% between over 48 hours and 72 hours. 3. In the test fishing, by-catches were so low(1.5∼3%) until 12 hours of soaking time passed By-catches were increased according to the soaking time addition on the over 24 hours of soaking time. The bait effect for sea-eel seems to be diminished as soon as the casting started and there was big difference in proportion to bait size and freshness.