• 한국수산과학회지
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• 제36권6호
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• pp.676-685
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• 2003

Seasonal variation of the fishery resource in the shallow waters of Ganghwado tidal flat was investigated using monthly collected samples with a fence net from June 1998 to May 1999. Thirty-six species were found including 27 fish species, 6 crustaceans, and 3 molluscs. Of the fish, Konosirus punctatus, Sardinella zunasi Liza haematocheila and Synechogobius hasta dominated in the number of individuals $(92.1\%)$ and in biomass $(94.5\%).$ A few number of resident species, such as L. haematocheila and S. hasta, were collected only during the cold months. As the water temperature increased in the spring, the adult migratory fish such as K. punctatus and S. zunasi, were collected. In the summer, the juvenile fish recruited in the shallow water showing a peak in fish abundance. The data suggested that they grew until late autumn before moving to deeper waters for over-wintering. The principal component analysis showed that the seasonal variation in species composition was principally determined by water temperature and/or water temperature related factors. The species composition of the fish assemblage in the study area suggested that these species are highly adapted to extreme seasonal temperature variation and high water turbidity.

• 한국환경과학회지
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• 제13권5호
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• pp.449-467
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• 2004

Interannual and decadal scale changes in body size of Pacific saury, catch and catch per unit effort were examined to investigate the environmental effects on the stock structure and abundance in the Tsushima Warm Current region. Interannual changes in thermal conditions are responsible for the different occurrence (catch) rates of sized group of the fish. Changes in body size due to environmental variables lead the stock to be homogeneous during the period of high abundance, while one of the reminder cohorts supports the stock during the period of low level of abundance. Migration circuits of two cohorts of saury stock are hypothesized on the basis of short life span and spatio-temporal changes of the stock structure in normal environmental conditions. Changes in upper ocean structure and production cycles by the decadal scale climate changes lead changes in stock structure and recruitment, resulting in the fluctuation of saury abundance. Hypothesized mechanism of the effects of climate changes on stock structure and abundance is illustrated on the basis of changes in thermal regime and production cycle.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2004년도 수산관련학회 공동학술대회 발표요지집
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• pp.169-171
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• 2004

Interannual and decadal scale body size of Pacific saury, catch and catch per unit effort were examined to investigate the environmental effects on the stock structure and abundance in the Tsushima Warm Current region. Interannual changes in thermal conditions are responsible for the different occurrence (catch) rates of sized group of the fish. Changes in body size due to environmental variables lead the stock to be homogeneous during the period of high abundance, while one of the reminder cohorts supports the stock during the period of low level of abundance. Migration circuits of two cohorts of saury stock are hypothesized on the basis of short life span and spatio-temporal changes in stock structure in normal environmental conditions. Changes in upper ocean structure and production cycles by the decadal scale climate changes lead changes in stock structure and recruitment, resulting in the fluctuation of saury abundance. Hypothesized mechanism of the effects of climate changes on the stock structure and abundance is illustrated on the basis of changes in thermal regime and production cycle.

• 수산해양기술연구
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• 제50권3호
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• pp.407-415
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• 2014

Fish was caught by a set net in Gwideok, Jeju island that was studied to determine monthly variation of species composition and catch from May 2005 to October 2006. Total catch was 54 species, 44,118 individuals, and 2,152,423.7 g during survey period. Dominant species were Trachurus japonicus and Siganus fuscescens that held 91.3% of total individuals and 71.3% of total abundance. The highest individuals and abundance of catch were in July 2005, and the lowest individuals and abundance of catch were in October 2006 and in October 2005, respectively. As the result, temporal change in abundance have corresponded with changing water temperature.

• 수산해양기술연구
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• 제45권4호
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• pp.201-210
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• 2009

Cast fishing gear needs some time for fishing progress, and catches and their composition by submerged time can change by several cause. Therefore, it is very importance to study fishing capacity of fishing gear by submerged time. This study is to investigate catches and their composition of shrimp trap, that is used in the coastal of the East Sea, and to find the fittest lifting time of trap. Experimental term are September 2006 and August 2007, the location is the coastal of Oho, Goseong, Gangwondo, Korea and one hundred trap is used at each casting and lifting of gear. For convenience of description, survey of 2006 and 2007 are dented as experimental code 1 and 2, and submerged time 21hr, 43hr and 66hr are dented as code A, B and C. The result of obtained from the above approach are summarized as follows: Many Northern shrimps(Pandalus eous), dominated 96.36%, are only catched in experimental code A, and in code B and C, some of coonstripe shrimp(Pandalus hypsinotus) and few morotoge shrimp(Pandalopsis japonica) are catched. CPUE of code 1A, 1B and 1C per trap were 21.67g, 29.51g and 28.48g, and those of code 2A, 2B and 2C per trap were 25.44g, 32.93g and 33.36g. Therefore, 24.66% of catch increased according as submerged time passes from 1 day to 2 days, and almost no change of catch was to be -1.1%. Carapace length of code 1A, 1B and 1C were 23.77mm, 25.00mm and 25.57mm, and those of code 2A, 2B and 2C per trap were 23.83mm, 24.95mm and 25.45mm. Thus, the more submerged time is, the less catch of small fish is and the more catch of large fish is. Consequently, fit lifting time of shrimp trap is after 2 days, and if considered trouble of fishing gear and condition of catch, the fittest lifting time is the third successive day of casting date.

• 한국수산과학회지
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• 제53권5호
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• pp.761-772
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• 2020

In order to study about species composition and community structure of fish in the coastal water off Boryeong were investigated from January 2018 to December 2019. A total of 10,863 individuals of 87 species of 44 families were collected. The dominant species were Liparis tanakai accounted for 19.8 percent of the total with Amblychaeturichthys hexanema and Collichthys niveatus accounted for 12.4 percent and 11.0 percent of the total number. A cluster analysis based on the Bray-Curtis similarity revealed that the fish community divided into two groups, According to season. The fish species that appeared summer and autumn were mainly migratory, while the fish species that appeared in spring and winter were mainly resident species. Fish caught by stow net had a high percentage of immature fish. It presented that coastal water off Boryeong is located an important spawning and nursery for fisheries resource.

• 수산해양기술연구
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• 제46권4호
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• pp.302-312
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• 2010

In order to describe the performance of a wedge type jellyfish excluder device, a series of fishing experiments was carried out in the coastal areas of Yokji Island, southern Korea in 2009, using a trawl net with a cover net. The body size and weight of each individual (fish or jellyfish) caught in the experimental fishing were measured. In the case of giant jellyfish the bell diameter and weight were measured. The catch species was composed of giant jellyfish (Nemopilema nomurai), silver croaker (Pennahia argentata), yellow croaker (Larimichthys polyactics), finespotted flounder (Pleuronichthys cornutus), largehead hairtail (Trichiuruslepturus), melon seed (Psenopsisanomala) and so on. The weight ratio and individual ratio of total fish escaped through the outlet of the excluder device were 0.322 and 0.320, respectively. The weight ratios of giant jellyfish excluded from the trawl net ranged from 0.740 to 0.921 (average 0.852/haul). It means that the wedge type jellyfish excluder device performed well and allowed the most of the giant jellyfish to exclude through the trawl net. The approximately 70% of fish entered in trawl net was caught. The wedge type excluder device needs some improvements to minimize the fish escape from the trawl nets in the future.

• 한국어류학회지
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• 제21권3호
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• pp.191-199
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• 2009

남해도 미조 정치망 어획물의 종 조성과 어획량 변동양상을 알아보기 위하여 2004년의 어기(3월 말부터 12월까지) 동안 매일 조사를 실시하였다. 조사기간 중 총 어종수 39종과 총 어획량 69,147.5 kg의 수산자원이 어획되었으며, 이중 어류가 33종 66,410.2 kg, 두족류가 5종 1,126.6 kg 그리고 갑각류가 1종, 1,610.7 kg을 차지하였다. 우점적으로 어획된 수산자원으로는 갈치, 까나리, 멸치, 삼치 등이며, 전체 어획량의 81.2%를 차지하였다. 이 외 정어리, 감성돔, 새우류, 살오징어 등이 소량 혼획되었으나, 전체 어획량에서 차지하는 비율은 낮았다. 우점어종 중에서 까나리는 봄철에 주로 어획되었고, 갈치와 삼치는 여름과 가을철에 그리고 멸치는 봄부터 가을철까지 계속 어획되었다. 미조 정치망의 어획량은 봄보다는 가을철 전후에 많이 어획되었는데, 이는 우점종인 갈치와 삼치의 어획량 증가에 따른 것이며, 이는 또한 $17^{\circ}C$ 이상의 어장 적수온과 관련이 있었다.

• 수산해양기술연구
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• 제42권1호
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• pp.1-10
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• 2006

Present study was conducted to improve the spring frame net trap for conger eel, Conger myriaster which prevents by-catch and protects immature fish. A series of comparative fishing experiment was carried out in water off the south-east coast of Korea from Nov. 2004 to Jul. 2005. And analyzed the amount of catch, by-catch rate, and CPUE, etc. of experimental traps which were the spring frame net traps, sorted four types of flappers. And the compared gear was a plastic conger eel pot. The conclusions were as follows. By-catch rates of spring frame net trap with the compressed flapper bound by nylon mono-filament was about 0-3%. CPUE of spring frame net trap with the compressed flapper was about 50-60% lower than that of traditional and plastic pot. And in case of conger eel that the total length is over 350mm, CPUE was little different on each type of flapper of every mesh size.

• 수산해양기술연구
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• 제53권3호
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• pp.266-275
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• 2017

The maximum sustained yield (MSY) of shellfish caught through dredge fishery was 7,250 to 7,490 MT from 1990 to 1999, which was not affected by the construction of the Saemangeum Dike. The MSY from 2000 to 2016, under the influence of the dike, was 1,716 to 1,776 MT when the total annual fish catch was 1,000 MT or more, and 289 to 336 MT when it was less than 1,000 MT. The construction of the Saemangeum Dike led to a decrease in the catch volume of the offshore dredge fishery in Jeollabuk-do, to 4.2 to 23.7% of that before its construction. The allowable biological catch (ABC) was estimated to be 313 to 1,532 MT per year, which was about 72.3 to 94.3% less than before the construction of Saemangeum Dike. Currently, the dredge fishery in Jeollabuk-do relies on comb pen shells. For fishery management, the catch per vessel should be set at 51.0 MT/year or less, and the number of fishing vessels should be reduced to 22 as quickly as possible. Besides, in the long term, the number of current fishing vessels should be reduced to less than half in consideration of the comb pen shell collecting period in Jeollabuk-do.