• 수산경영론집
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• 제27권2호
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• pp.27-49
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• 1996

The purpose of this paper is to find out how catches of certain species of marine fish in China influence the marine fisheries of Korea. The results are as follows: 1) While the catches of the main species of marine fish are over 74% in Korea, those of China are under 45%. 2) The main species of marine fish in China(MFC) are hair tails, jack mackerels, anchovies, mackerels, Spanish mackerels, pomfrets, redlip croakers, fie fish, sea breams, sardines, croakers and bigeyed herrings. 3) All the MFC belong to the main species of marine fish in Korea. 4) The fishing grounds of hair tails, jack mackerels, mackerels, Spanish mackerels, pomfrets and croakers in China are similar to those of Korea. 5) Catches of hair tails, jack mackerels, Spanish mackerels, pomfrets, file fish, sea breams and bigeyed herrings in China are many times more than those in Korea. Therefore Korea can't compete with China with such species of marine fish. 6) The price of MFC apart from mackerels and sardines is more competitive than the price of such species in Korea. When the catches of China's marine fish are imported, the species of China's marine fish that will have a great influence on the marine fisheries of Korea are hair tails, jack mackerels, pomfrets and sea breams.

• 한국어류학회지
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• 제12권1호
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• pp.62-70
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• 2000

1997년 7월부터 1999년 6월까지 2년간 제주도 남부 해역인 하예동 연안에서 매월 채집한 쥐치, Stephanolepis cirrhifer의 생식주기를 조직학적 방법으로 연구하였다. 암 수컷의 월별 GSI 변화는 월별 수온과 광주기 변화양상과 거의 유사하게 변화하였고 암 수컷 모두 GSI값이 6월에 년 중 최고값을 보였다. 생식주기는 암컷인 경우 성장기 2~5월, 성숙기 5~6월, 산란기 6~8월, 퇴화 및 휴지기 9~12월로 구분되고, 수컷인 경우 성장기 2~4월, 성숙기 5~6월, 방정기 6~8월, 퇴화 및 휴지기 9~1월로 구분할 수 있었다. 성숙시기에 쥐치의 난소를 조직학적으로 관찰한 결과 난소내에는 여러 발달 단계의 난모세포들이 분포하여 비동시발달형에 속하는 어종으로 판단되며 산란기동안 적어도 2회 이상 산란하는 다회산란어에 속하는 어종으로 사려된다.

• 수산해양기술연구
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• 제51권4호
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• pp.567-575
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• 2015

Species composition in the coastal waters off Ulleungdo of Korea were examined based on catches bimonthly collected by trammel net in 2013. A total of 711 individuals and 181.9 Kg were caught and catches were composed of 4 classes 15 orders 27 families 52 species including 44 Pisces, 4 Gastropoda, 3 Cephalopoda, and 1 Echinodermata. The dominant species in biomass were File fish (Thamnaconus modestus), Atka mackerel (Pleurogrammus azonus), and Greenling (Hexagrammos otakii). Data were summarized using hierarchical cluster analysis (HCA) and detrended correspondence analysis (DCA) to examine similarity in species composition for each month, and community structure in Ulleungdo was divided into two groups. Community structures in February, April and December with low temperature and well-mixed surface water were distinguished from those in June, August and October with high temperature and strong stratification, which could be attributed to temporal changes in dominant species. Atka mackerel and Spear squid mainly caught in February and April, disappearing in June, August and October, and File fish outburst was shown in October. Because the water off Ulleungdo has been under low human pressure, it could be a good case study to elucidate effects of climate change on community structure and ecosystem in the East sea. Continuous surveys and further studies are required to demonstrate migration route and distribution of dominant species and long-term changes in community structure in the water of Ulleungdo.

• Journal of Advanced Marine Engineering and Technology
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• 제32권1호
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• pp.153-161
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• 2008

Recently, the research and development of the fish cage in open sea from domestic is active and it is almost complement with commercial scale test on 'seogwipo'. But domestic technology is not sufficient of management RMS(Remote Monitoring System) with advanced country, so it is difficult to maintenance and monitor fish cage in open sea. This paper introduces a fish cage environmental monitoring system for measuring pH, DO and temperature. A signal is treated with DAU(Data Acquisition Unit) by a wireless communication method and transfers data to host computer for data processing. These data are graphically shown on the monitor with LabVIEW program and logged on the data processing system in the form of file.

• 수산해양기술연구
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• 제28권3호
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• pp.243-251
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• 1992

The author examined the response of File fish, Stephanolepis Cirrhifer (TEMMINCK et SCHLEGEL) to the surface attracting lamps(0.5W, 0.8W, 1W) line in the experimental water tank (550L$\times$58W$\times$73H cm). the attracting rate was investigated in accordance with the interval of lighting and putting out hour (1, 5 minute)when each of the attracting lamps was gradually switched off after they were switched on all at once. The results are as follows: 1. Total distribution rate of fish in the illuminated section was 96.9%(mean 19.4%) in case of 1 minute interval, and 98.4%(mean 19.7%) in case of 5 minutes interval. 2. Mean distribution rate of fish at the illuminated section: \circled1 Distribution rate at interval of 1 minute were 19.9% in 0.8W, 19.3% in 1W and 18.9% in 0.5W respectively. \circled2 Distribution rate at interval of 5 minutes were 19.8% in 1W, 19.8% in 0.8W, and 19.5% in 0.5W respectively. 3. Attracting rate of the last section showed increasing as illuminating time elapse without interval and lighting source. 4. Attracting rate of fish in only last section switched on: \circled1 Attracting rate at interval in case of 1 minute were 98.0% in 1W, 97.0% in 0.5W and 83.0% in 0.8W respectively. \circled2 Attracting rate at interval in case of 5 minutes were 99.3% in 1W, 97.3% in 0.5W and 93.3% in 0.8W respectively.

• 한국수산과학회지
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• 제16권2호
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• pp.147-153
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• 1983

To check the differences of the digestive enzymes by the bait habits and the proteolytic activities of the fissile extracts from the fish, omnivorous filefish (Navodon modestus), carnivorous cat shark (Scilliorhinus tarazame) and bloodsucking hag fish (Eptatretus burgeri) were sampled for this experiment. The activity of crude alkaline protease extracted from the muscle and the internal organs of the samples was determined with casein as substrate. The activity of the proteolytic enzymes showed remarkable differences by the organs of the fish. The optimum condition of the pretenses from the muscle revealed in range of pH 7.8-8.3, at $60-65^{\circ}C$, while those of the enzymes from the internal organs were at about pH 8.2, $45-55^{\circ}C$, but those of hag fish were at about pH 6.7, $45-55^{\circ}C$. The proteolytic activity of the enzyme of alimentary canal in filefish and in hag fish was 57 and 11 times stronger than that of muscle, respectively. The crude enzyme from the alimentary canal of file fish showed the strongest proteolytic activity in samples submitted and that of cat shark was the lowest. The activity of pancreatic alkaline protease in cat shark was 50 fold higher than that of muscle alkaline protease in the fish.

• 한국어류학회지
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• 제31권4호
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• pp.201-207
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• 2019

수온은 양식어류의 생존에 영향을 미치는 가장 주요한 환경 요인이며, 겨울철 급작스런 수온 하강은 양식어류의 질병과 집단폐사 발생의 요인이 되기도 한다. 본 연구는 겨울철 수온 하강으로 인해 빈번하게 폐사가 발생하고 있는 말쥐치의 양식관리를 위한 기초자료로 활용하기 위해 말쥐치의 하한수온내 성범위, 산소소비율, 혈액학적 및 조직학적 반응을 조사하였다. 수온 5℃에서 노출 3일째, 수온 6℃에서는 노출 4일째 모두 폐사하여 말쥐치의 저수온에 대한 반수치사 하한수온은(LT₅₀) 6.97℃ (6.69~7.27℃)였다. 산소소비율은 수온 하강에 따라 감소하여 수온 간 유의한 차이(p<0.05)를 나타내었다. 혈액내 활성산소 소거효소인 SOD활성도는 대조구 10℃에 비해 수온 6℃에서 유의하게 상승하였다(p<0.05). 반면 CAT는 실험수온 간에 유의한 변화를 나타내지 않았다(p>0.05), 삼투질농도는 대조구와 실험수온 간 유의한 차이는 나타나지 않았다(p>0.05). 코티졸은 대조구에 비해 수온 하강에 따라 증가하였으며 수온 간 유의한 차이를 나타내었다(p<0.05). 간의 조직학적 변화는 혈관내 혈구의 감소, 간세포의 공포화와 간세포 핵의 응축, 췌장 외분비 선세포의 위축 및 효소원과립들이 감소하였다.

• 수산해양기술연구
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• 제22권4호
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• pp.71-74
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• 1986

The author tried to clarify the distribution of the total length and body weight of the file h, Navodos modcstus, caught by trawl net during July, 1984 in the southern sea korea. Among the catches of five times fishing operation, 1540 individuals were randomly sampled for the measurement. The results are summarized as follows; " The distribution of total length showed bimodal type, wbich was able to analyzed into two normal distributions N(17.46, 1. 02^2) and N(22.09, 1. 77^2). And smaller group was much than older one. The age of the sample estimated from the total length distribution of. smaller group was 1. 5 to 2, and the larger group 2. 5 to 4. The relationship between the total length and the body weight can be presented as following equation: $$W=0.01726 L^{2.8507}$$ ' or $$W= 0.01109 L^{3.0}$$ or $$W= 0.01109 L^{3.0}$$.

• 수산해양기술연구
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• 제28권4호
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• pp.418-429
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• 1992

Recently, many researchers make a great effort to develop high efficient marine diesel engines using low grade heavy oil, and also study substitution fuel oil for engines and boilers. In case of Fisheries Vessels, we need to know that fish oil can be substituted for fuel oil. Therefore, it is studied that evaporation, ignition and combustion phenomena of the single droplet of fish oils (i.e., Sardine fish oil, File fish oil and Alaska pollac oil) on heated plane surface to evaluate appropriateness as substitution oil. Methanol and light oil are tested simultaneously to help the evaluation on these Fish oils. The results are summarized as follows: 1. The type of evaporation and combustion is spherical evaporation in case of methanol and light oil. And fish oil blended with light oil was finished after spherical evaporation happen when high temperature. 2. Ignition of Pure fish oil was shorter than that of fish oil blended with light oil. 3. Heat transferred to droplet could make qualitative comparison by contact diameter of droplet with hot surface as time changes. Life time of droplet according to the change of heated surface temperature was greatly influenced by droplet contact condition on the heated surface. 4. As far as combustion phenomena was concerned, apparent diameter of the fish oil droplet increased after ignition and decreased suddenly by internal boiling of droplet. 5. Three fish oils had similar phenomena on the evaporation, ignition and combustion. 6. Evaporation and combustion feature of fish oil could not be shown by coefficient of evaporation velocity of droplet and coefficient of combustion velocity of droplet.

• Ocean and Polar Research
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• 제27권3호
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• pp.311-322
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• 2005

Fisheries buyback programs in Korea have been implemented since 1994, and their scales are estimated to be the present value of 930 billion won for the last 9 yens since 1994. The paper attempts to identify the patterns of each fish species, of which their yields can be steadily increased or significant]y decreased, and to evaluate its effective level and the optimal level for buyback programs by means of fishing capacity analysis. The paper distinguishes fish species, that there is no need to reduce the fishing efforts, such as anchovies, mackerels, squids, Spanish mackerels, and herrings, because MSY exceeds yields, from fish species to control overfishing such as file fish, yellow corvenias, young pollack, hair tail, snow crab, and pollack. The paper also suggests that 65% of the fishing efforts (total tonnages) should be cut back at the national aggregate level in order to restore fish stocks.