• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.3
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• pp.131-138
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• 1988

Collection of organisms for the fisheries resources community were obtained with a set net during 8 months between May, 1985 and May, 1986 on the coast of Pukchon, Cheju Island, Korea. Most of organisms, representing 36 species, were less than 20cm $(93\%)$ in length, and 130g $(91\%)$ in weight. The four most abundant species were jack mackerel, Trachurus japonicus ; squid, Todarodes pacificus : damsel fish, Chromis notatus : and rabbit fish, Siganus fuscescens, which comprised about $83\% in number and about $73\%$ of the total catch. The diversity index of the number of species and information indices for individual and catch were the highest in October and the lowest in Septemer, indicating a close relationship with the change between the species number and catch at that time. A cluster analysis of 17 species was illustrated from the similarity matrix. All of the 17 species were grouped at the 0.2 similarity level. Three groups were present at 0.60 level, whereas species in other groups were sporadic in occurrence.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.54-55
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• 2003

해수관상용으로 그 인기도가 높은 상어류는 모두가 자연에서 채집된 후 관람용 대형수조 또는 개인용 소형수조 내에서 순치 후 관상용으로 사육되고 있다. 그러나, 자연에서 채집된 대부분의 개체는 인위적인 수조 시설 내에서의 생활에 적응하는데 실패하여 결국 거의 대부분의 개체가 짧은 기간 내에 사망하게 된다. 따라서 이 연구는 인공 종묘 생산 시설에서 해수 관상용 상어류의 종묘 확보를 목적으로 실시하였다. 우리나라 제주 연안에서 채집이 비교적 용이한 까치상어 Triakis scyllium와 별상어 Cynias manazo 2종의 상어 친어를 확보하여 인공 사육 시설에서 사육하면서 수조 내에서의 자연 교미와 자연 산란에 성공하였다. 친어와 치상어의 사육관리는 자연해수를 사용하여 15~40ton 크기의 콘크리트 수조에서 사육하면서 전갱이와 같은 생사료 또는 전갱이와 어분을 주성분으로 하는 습사료를 만들어 1일 1회 급이하였다. 까치상어의 인공 종묘는 수 차례의 사산을 거듭한 끝에 2003년 5월 18일과 6월 8일 두 차례에 걸쳐서 매우 활력이 좋은 상태의 치어가 출산하였다. 별상어도 수 차례의 사산을 거듭한 끝에 2003년 5월 25일 건강한 상태의 치어를 출산시키는데 성공하였다. 지금까지 산출된 까치상어의 출산시 평균 전장은 25.70$\pm$0.88cm 평균 체중은 58.32$\pm$4.86g이었으며, 별상어의 출산시 치어의 평균 전장은 27.26$\pm$0.57cm였고 평균 체중은 55.32$\pm$1.69g로 두 종 상어의 평균 전장과 평균 체중은 유사한 경향을 보였다. 그러나, 산출 후 사육 관리 과정에서 관찰된 까치상어와 별상어의 월간 성장 중 전장을 비교한 결과, 까치상어는 1개월 전 대비 15.06%의 성장을 보였으나, 별상어는 3.15%의 성장을 보여 까치상어 보다는 별상어의 길이 성장이 느린 것을 알 수 있었다. 까치상어와 별상어의 월간 성장 중 체중을 비교한 결과에서도 까치상어는 1개월 전 대비 34.11%의 성장을 보였으나, 별상어는 2.25%의 성장을 보여 까치상어 보다는 별상어의 체중 성장이 매우 느린 것을 알 수 있었다. 출산 관리중인 까치상어와 별상어 치어의 성비를 조사한 결과, 까치상어는 ♀:♂=1:1.28, 별상어는 ♀:♂=1:2.50으로 별상어의 암 수 성비가 매우 불균형한 것을 알 수 있었다. 그리고 까치상어와 별상어의 암ㆍ수간 성장 차이를 조사한 결과, 까치상어와 별상어의 암ㆍ수간 성장 (전장, 체장 및 체중)에는 큰 차이가 없었다. 현재, 인공 사육 시설에서 관리중인 까치상어는 64마리이며 별상어는 7마리이다. 결국 소형의 수족관내에서 해수 관상어로서 사육하기 위한 조건으로서 너무 급격한 성장을 하는 어종인 경우에는 관상 기간이 짧아져 조기 폐기하여야 하는 단점을 감안하면 까치상어 보다는 별상어의 관상가치가 높을 것으로 판단되며, 반대로 대형 관람용 수족관의 경우에서는 별상어 보다 성장이 빠르고 운동력이 활발한 까치상어를 전시관람용으로 이용할 경우 전시효과가 높을 것으로 판단된다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.708-716
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• 2013

Changes in the proximate composition, lipid classes, and fatty acids were studied in chub mackerel Scomber japonicus and Japanese jack mackerel Trachurus japonicus muscles cooked using a frying pan, oven, and microwave oven. The moisture content was high in the raw samples (chub mackerel 65.5%, Japanese jack mackerel 60.5%) and decreased with cooking, especially in the frying pan method (chub mackerel 49.2%, Japanese jack mackerel 49.8%). In contrast, the protein, lipid and ash contents increased significantly with cooking in chub mackerel muscle (P<0.05). However, the lipid content of Japanese jack mackerel muscle showed no significant difference between the samples using the three cooking methods and the raw sample. The dripped lipid contents from the cooked muscles showed the highest levels in the frying pan samples and the lowest levels in the microwave oven samples. The percentage of non-polar lipid (NL) in the total lipid content was over 95% in the muscle lipids (10.43-21.86 g/100 g sample). Prominent fatty acids were 16:0, 18:1n-9, 22:6n-3 (docosahexaenoic acid, DHA), 16:1n-7 and 20:5n-3 (eicosapentaenoic acid, EPA) in both fish muscles and dripped lipids. There was no change in the EPA level in any of the fish muscles, by any cooking method. The percentage of DHA in the muscle of chub mackerel showed the lowest level in the frying pan sample and the highest level in the microwave oven and raw samples, and an intermediate level in the oven sample. However, the percentage of DHA in the Japanese jack mackerel muscle was not significantly different between the various cooking methods. From these results, the microwave oven and oven cooking methods showed relatively low levels of dripped lipid content and loss of n-3 PUFA compared with the frying pan cooking method.

• Korean Journal of Ichthyology
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• v.20 no.2
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• pp.105-111
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• 2008

A pelagic tuna longline research cruise in the eastern and central Pacific Ocean from September to October of 2006 was conducted to compare catch rates with the use of different hook type and bait combinations. Traditional tuna hooks (J 4) and three circle hook types (C15, C16, C18), along with five bait types (chub mackerel (CM), jack mackerel (JM), milkfish (MF), sardine (SD), and squid (SQ)) and hook number as a proxy for hook depth were evaluated for their effect on bigeye tuna catch rates (fish per 1,000 hooks) using Generalized Linear Models (GLMs). Results from 28 sets indicated significant differences in bigeye catch rates between individual longline sets and hook number. The GLM explained 33% of the deviance in bigeye catch rates with these two factors. An alternative model formulation included bait type which had a small effect (explaining 2.7% of the deviance) on catch rates. Hook type had a negligible and non-significant effect in the GLMs. These results indicate that all of the hooks and baits tested are equally effective at catching bigeye tuna and that hook number (depth) was the paramount operational factor in explaining bigeye tuna catch rates.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.1
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• pp.105-111
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• 1999

To investigate the relationships between ocean environmental characteristics and thechange of the catch, we analyzed various environmental factors such as mean temperature, salinity, current vectors, lunar day and wind vectors from 1995 to 1996 and the catch fluctuation of Hanlim set net from 1994 to 1996. The results are as follow ; 1) The proportion of fishes caught in Hanlim set net is highest for horse mackere1 ($69.2\%$) and is followed by common mackerel ($18.4\%$), hair tail ($5.6\%$), squid ($2.7\%$) and rabbit fish ($1.4\%$) in order. Two peaks in the monthly catch appeared in June and October in the operation period of May- December. 2) The flow direction was northward in flood time and southeastward in ebb time around the Hanlim set net. Thus, the vortical mixing of sea water was active and continued for more than 3 hours. In addition, mean daily temperature was low due to the presence of middle and bottom water in offshore. Increase in salinity or high salinity of sea water provides a favorable condition for catches of fishes. Catches in the first quarter and the last quarter of the moon were larger than that in full moon and the last of the month. In particular, when south or southeasterly wind velocity reaches about 3$\~$6.5 m/s, the possibility of catches increases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.1
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• pp.56-62
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• 1986

Marine fishes, sardine(Sardinops melanosticta), scad kingfish(Caranx equula), horse mackerel(Trachurus japonicus) and file fish(Navodon modestus), were stored for fifty days with partial freezing at$-3.5^{\circ}C$. During the storage, the changes in microflora and volatile nitrogen content was investigated. The fishes exhibited $10^4\;to\;10^6$ of bacterial cells per square centimeter of their skin just before they were submitted to the storage. The bacterial cell number was increased as $10^6\;to\;10^8$ cells as the storage time passed over twenty-two days. Offensive odor which is typical in the spoilage of fishes became strong as increase the bacterial cell numbe. The major isolates among the three hundred strains of bacteria isolated from the fish skins were identified as Pseudomonas I/II, III/IV-H, Vibrio and Moraxella. The same was found in the spoiled fishes, however, Pseudomonas I/II, was predominant on contrast to that of fresh fishes. Pseudomonas III/IV-NH, Flavobacterium, Cytophaga and Micrococcus were also found in early period of storage, but they disappeared as the progress of storage. Nine per cent of isolates were unidentified.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.422-430
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• 2016

We investigated the abundance and composition of the zooplankton community around Dokdo in the East Sea from 2006 to 2015. Zooplankton samples were collected in the surface mixed layer by vertical hauls using a standard type net at the monitoring stations. There were no clear long-term trends in the average temperature and salinity, but relatively low salinity was recorded in the summer of 2013 and 2015. The average abundances of zooplankton in the summer increased by two orders of magnitude from $317inds./m^3$ in 2008 to $10,242inds./m^3$ in 2015. This long-term increase was accompanied by a slight increase in the chlorophyll-a concentration and a decrease in the catch of potential crucial predators (anchovy, mackerel pike, squid, herring and horse mackerel) in the study area. The dominant zooplankton, accounting for most of the long-term increase, consisted of appendicularian (Oikopleura spp.), which showed a steady increase since 2012, summer species such as Noctiluca scintillans and the cladoceran Penilia avirostris, which showed an abrupt increase, and the copepod Paracalanus parvus s.l., which showed a rapid increase after its first occurrence in summer 2010. These results suggest that the long-term increase of zooplankton could be related to the increase in the concentration of prey and the decrease in the predation pressure of potential predators around Dokdo in the study area.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.95-106
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• 2021

In order to understand the seasonal variations of species composition of fish in the Goseong, middle East Sea of Korea, we surveyed fish fauna using set net during 2 years. In this study, a total of 77 taxa belonging to 40 families were collected and 75 species were identified. The dominant family were Tetraodontidae and Pleuronectidae, and the dominant species were Arctoscopus japonicus, Konosirus punctatus, Stephanolepis cirrhifer, Thamnaconus modestus, and Trachurus japonicus. The results of the hierarchical clustering using the number of individuals of collected species showed that they are divided into three seasonal groups: Group A (Jan.~Apr.), Group B (May~Jun., Nov.~Dec.), Group C (Jul.~Oct.). The sea surface temperature (SST) was higher than the results of previous studies in winter and spring, and species composition in spring have changed from cold-water species to the warm-water species, recently. The species composition has become similar to the that of southern Gangwon-do regions (Samcheok and Gangneung) of the previous studies. The species diversity of family Tetraodontidae has increased, which is estimated to have an effect on increase in SST and the quantity of entering the East Sea. Therefore, we assumed that the change of species composition is related to the extension of northern distribution limits and survival temperature, and abundant preys. Therefore, it is necessary that an efficient resource management policy as well as the ways of commercially use of migratory warm-water fish, rapidly.

• Korean Journal of Ichthyology
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• v.34 no.1
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• pp.44-56
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• 2022

Fish fauna was observed off the coast of Busan (Cheongsapo) and Ulsan (Bangeojin) using underwater visual census from November 2016 to October 2017. A total of 1,486 individuals of 25 species in Cheongsapo and 3,859 individuals of 31 species were identified in Bangeojin. Dominant species in the number of individuals were Trachurus japonicus (20.9%), Halichoeres tenuispinis (12.6%), and Chromis notata (11.9%) in Cheongsapo, Siganus fuscescens (42.0%), Pempheris japonica (8.4%), and Chromis notata (8.0%) in Bangeojin. There was no significant difference in the species composition of Cheongsapo and Bangeojin but spring vs. summer, spring vs. autumn, summer vs. winter, autumn vs. winter showed a significant difference. Contribution species of seasonal differences were commonly high rates by Halichoeres tenuispinis and Parajulis poecilepterus. Of the total 38 species, 17 (44.7%) temperate, 6 (15.8%) tropical, and 15 (39.5%) subtropical species observed coastal waters off Cheongsapo and Bangeojin.

• Korean Journal of Ichthyology
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• v.36 no.2
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• pp.174-181
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• 2024

This study examines the community characteristics of fish species collected by fyke net from the eastern coastal waters of Yeosu, Korea, during the period from 2020 to 2021. A total of 4,539 fish were sampled and classified into 43 species, 28 families, and 7 orders. The dominant species included Mugil cephalus (14.4%), Konosirus punctatus (10.9%), Lateolabrax japonicus (8.3%), Acanthopagrus schlegelii (7.9%), and Pennahia argentata (7.2%). The diversity index was highest in October (H'=2.888) and lowest in February (H'=2.075). Furthermore, the dominance index was highest in March (DI=0.524) and lowest in December (DI=0.178). Hierarchical cluster analysis (HCA) revealed that fish communities could be divided into three groups based on Bray-Curtis similarity. Group 1, consisting mainly of species collected from June to October, formed one cluster. Group 2, including winter spawning species such as Pseudopleuronectes yokohamae, Clupea pallasii, and Hexagrammos otakii, sampled from November to February, formed another cluster. Group 3, which included species such as Larimichthys polyactis, Amblychaeturichthys hexanema, and Sebastes inermis, formed a cluster collected from March to May. The eastern coast of Yeosu is considered a suitable habitat for fisheries resources, including highly economically valuable species, and it is also assumed to be an important spawning and nursery ground for many fish species.