• 한국수산과학회지
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• 제5권1호
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• pp.11-16
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• 1972

1969년 $6\~11$월까지 삼치를 대상으로 Multi-f.망과 Mono-f.망을 사용하여 시험 조업한 결과는 다음과 같다. 1. 80mm에서 115mm까지 7가지 망목으로 된 유자망에서 어획된 삼치의 어체는 $500\~2,900gr$의 범위였다. 이중 가장 많이 어획되는 체중은 1,000gr 1,300gr 및 1,500gr으로서 그 빈도는 각각 $21%,\;15%$ 및 $19%$였다. 2. 상기 세군의 삼치를 어획하기 위한 적정 망목은 Multi-f.망은 80mm 이상 105mm 이하의 망목이고, Mono-f. 망은 80mm보다 약간 작은 망목에서부터 105mm이하의 망목이다. 3. 어체의 헝태가 방추형이고 크기가 거의 동일한 단일 어종을 어획 대상으로 할 때는 Mono-f. 망이 Multi-f. 망의 약 1,5배 정도의 어획 효과를 나타내고, 기타 잡어에 대해서는 Multi-f. 망이 어획이 좋다. 4. 동일한 망목에서는 multi-f. 망은 소형어의 어획율이 높고, Mono-f. 망에는 대형어의 어획율이 높은 경향이 있다.

• 한국수산과학회지
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• 제43권6호
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• pp.693-704
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• 2010

Seasonal variation in species composition around Dokdo, East Sea of Korea, was investigated using trammel-net catches, from 2006 to 2009. A total of 53 fish species belonging to 23 families in 12 orders were captured; the orders Perciformes (12 families, 22 species) and Scorpaeniformes (four families, 22 species) were dominant. Between 2008 and 2009, 43 species were collected by trammel net. The number of species was highest in August 2009 (25 species) and lowest in February 2009 (11 species). The number of individuals and total biomass peaked in November 2009. Diversity indices for fish catches were highest in August 2008 (2.4368) and lowest in November 2009 (0.4253). The dominant species were Thamnaconus modestus and Sebastes schlegeli. Hierarchical clustering analysis showed five fish groups, with frequency and number of individuals similar to results of correspondence analysis (CA), which showed a closer relationship to the year term than the season term. CA showed that temperature was an important factor influencing fish species richness and abundance. Three main fish assemblage types coexisted around Dokdo: an East Sea coastal fish assemblage, a subtropical fish assemblage, and a cold water fish assemblage.

• 한국수산과학회지
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• 제47권6호
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• pp.945-959
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• 2014

This study was conducted to provide basic data for optimal fisheries management through the accurate understanding the catches, fishing level, species composition, distribution characteristics and fisheries status of trammel net in Gangwon Province. As the results of trammel net survey, Pisces were collected 77 species, 1,983.0 kg, Crustacea 9 species, 569.0 kg, Cephalopoda 5 species, 75.3 kg, Gastropoda 12 species, 16.5 kg in the coastal waters of Sokcho and Pisces 55 species, 3,681.5 kg, Crustacea 6 species, 2,229.8 kg, Gastropoda 10 species, 72.8 kg, Cephalopoda 4 species, 10.1 kg in the coastal waters of Donghae, respectively. The catches of important species with season and depths showed that the main target species is Pleuronectidae spp. at all depth and Aptocyclus ventricosus at <100 m in Sokcho, Liparis spp. and Dasycottus setiger at 200-500 m in Donghae, respectively. The mean total length (cm) of Gadus macrocephalus and Aptocyclus ventricosus didn't appear significant difference, but the mean total length of Pleuronectidae spp., Liparis spp. and D. setiger in Donghae is bigger than in Sokcho. From the cluster and MDS analysis based on Bray-Curtis similarity matrix of fourth root transformed, catches data of dominant species in the coastal waters of Sokcho and Donghae was divided into three different groups of the demersal organisms community in 12 survey of Donghae (Group A) and Jul., Oct.-Dec. survey of Sokcho (Group B) and Jan.-Jun. and Aug.-Sep. survey of Sokcho (Group C).

• 한국수산과학회지
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• 제36권6호
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• pp.749-756
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• 2003

Hydroacoustic and open-closing zooplankton net survey were conducted to understand the characteristics of the sound scattering layer (SSL) and to estimate the density of an euphausiid (Euphausia pacifica) in the SSL, in the northwestern part of the East China Sea. The survey was carried out during July 6-9 2002 at 8 sampling stations for zooplankton. The virtual echogram technique was used to identify E. pacifica from all acoustic scatters. Mean volume backscattering strength difference $(MVBS_{120kHz-38kHz})$ and target strength equation for E. pacifica were derived from the Distorted-wave Born Approximation (DWBA) model. Although vertical migration of the SSL is similar to the general pattern, dispersion at night shows some differences. Estimated mean density using acoustic data ranged from $20.4-221.4\;mg/m^3$ over the whole depth, and $87.1-553.5\;mg/m^3$ in the SSL. The density using the zooplankton net ranged from $0.2-362.4\;mg/m^3$ and was not related to net deploying method. The results from the acoustic and net survey suggest that E. pacifica might be an important zooplankton community in the northwestern part of the East China Sea.

• 한국수산과학회지
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• 제55권5호
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• pp.625-637
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• 2022

The southern coast of the East Sea is an important area affected by large warm currents as it connects the coastal waters of Jeju Island, the South Sea, and Dokdo. From 2017 to 2021, the average catch per unit effort (CPUE; kg/day/ship) of set net fishery at six ports in the Gyeongbuk region off the southern coast of the East Sea was the highest in Gampo, Gyeongju, and the lowest in Hupo, Uljin. Although the seasonal variation in the CPUE differed by region and year, it was generally high in autumn. In the set net fishery in Pohang from 2019 to 2021, we identified 72 species, which decreased to 56 species in 2019, 46 in 2020, and 41 in 2021. The species diversity index slightly increased over the three-year periods. We found positive correlations between the total catch (kg) of subtropical species in autumn and the water temperature at 50 m. Among the most abundant species, we found substantially positive correlations between the CPUE of Scomber japonicus, Scomberomous spp. and Carangids. We also noted positive correlations between the CPUE of Todarodes pacificus, Seriola spp. and Carangids.

• Fisheries and Aquatic Sciences
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• 제27권5호
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• pp.265-275
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• 2024

The success of establishing the Indonesian growing fast hybrid carp, namely "Permata", on a controlled environmental test must be followed up with a large-scale test. This study aims to evaluate the phenotypic performance of the Permata hybrid carp in multi-locations with different cultivation systems. The test sites consisted of floating net cages, running-water ponds, semi-concrete ponds, earthen ponds, fully concrete ponds, and static net cages. For 90 days, fish were fed commercial pellets with a 28%-30% protein content. At the end of the test, all fish were harvested and counted. Data on length, weight, survival rate, and harvested biomass were used to analyze the effect of genotype, environment, and their interaction on the phenotypic performance. The growth based on final weight is used to analyze the stability performance in each test location. The results showed that the length and weight of common carp were significantly affected by genotype and the environment, but not by the interaction of both. The genotype, environment, and the interaction of both factors affected common carp's survival and harvested biomass. Common carp reared in floating net cages generally had the best performance, while carp reared in fully concrete tanks and static net cages had the lowest. The growth stability analysis showed that the common carp in this study were unstable genotypes but have a broad adaptability in term of different environments.

• 수산해양기술연구
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• 제59권4호
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• pp.279-289
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• 2023

The United States enforces the seafood import regulations so-called the Marine Mammal Protection Act (MMPA), and by 2023, all exports of aquatic products and processed fish products by fisheries which have not obtained an "Comparability Finding" from the National Oceanic and Atmospheric Administration will be completely banned. Therefore, to respond to the US MMPA, it is critical to identify technologies and methods used in worldwide for reducing bycatch of marine mammals. In particular, marine mammals are frequently caught in five fisheries (trawl, gill net, trap, stow net and set net) in Korea, which is facing a great challenge. This study presented bycatch reduction methods by five fisheries, classified the methods by country, and suggested appropriate reduction methods which can be applied in Korea.

• 한국수산과학회지
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• 제21권3호
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• pp.184-192
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• 1988

제주도 연안에서 분기초망어선의 집어등에 의해 집어된 멸치의 집어상태를 1987년5월~8월간에 매월 중순을 기준하여 223해구와 233해구에서 분기초망어선에 어군탐지기(SR-385형)를 설치하여 수면상 2m 높이에 선수 전방 1m에 수상집어등 1Kw, 백열등 1개를 교류전압 100V로 수면에 조사했을 때의 멸치군의 유영수심, 집어등의 수중조도, 어획량의 변동, 그에 따른 집어효과를 조사한 결과는 다음과 같다. 1. 분기초망에 의한 멸치의 어획량은 월령의 상순 (1-10일)과 하순 (20-30일)에 전 어획량(259 M/T)의 $90\%$가 어획되는 반면 중순 (11-20일)에는 전어획량의 $10\%$정도로 낮았다. 2. 수상집어등에 의한 멸치군의 집어수심은 2~5m였고, 이 때의 수중조도는 223해구에서 20~42 Lux, 233해구에서는 24~48 Lux이다. 3. 수면상 2m 높이인 멸치 분기초망어선의 선수에 수상집어등 1Kw 백열등 1개를 교류전압 100V로 집어한 결과 수중조도 1.9~7 Lux인 수심 10~15m에서 유영하던 멸치군이 수중조도 20~42 Lux인 수심 2~5m까지 부상하므로서 분기초망어선의 집어등에 의해 집어되는 멸치군의 수중조도는 집어하기 이전의 수중조도보다 7~12배 정도 더 강한 수중조도 범위에 집어되었다. 4. 현재 제주도 연안에서 조업하고 있는 멸치분기초망의 어획수심은 수심 2~3m 까지이고, 최종 어획단계에서 수상집어등을 교류전압 100V에서 80V로 강압하므로서 집어등을 2m 높이에서 4m 높이로 이동시키지 않더라도 같은 집어효과를 얻을 수 있다.

• 한국수산과학회지
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• 제48권6호
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• pp.947-959
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• 2015

Variations in the species composition, biomass and size distribution of fisheries resources in the Uljin marine ranching area were investigated using trammel nets at two stations (artificial reef and natural rocky area) from 2009 to 2010. During the survey, a total of 74 species were sampled with a mean density of 132 ind./net and mean biomass of 21.56 kg/net. In the natural rocky area, a total of 45 species were sampled at a mean density of 202 ind./net and mean biomass of 28.81 kg/net, while in the artificial reef area, samples included a total of 56 species, with means of 62 ind./net and 14.30 kg/net. The dominant species, comprising over 3% of the total number of individuals, were Suberites ficus (30.8%), Ovalipes punctatus (19.2%), Paralichthys olivaceus (11.7%), Pleuronectes herzensteini (4.7%), Kareius bicoloratus (3.5%), Pseudopleuronectes yokohamae (3.5%) and Eopsetta grigorjewi (3.0%). The dominant species, in terms of biomass, comprising over 5% of the total biomass, were P. olivaceus (22.1%), S. ficus (18.7%), O. punctatus (7.2%), Hexagrammos otakii (6.6%), P. yokohamae (5.7%), K. bicoloratus and P. herzensteini (5.3%). A cluster analysis and non-metric multidimensional scaling (nMDS) analysis based on the Bray-Curtis similarity of fourth root transformed data for number of species and individuals, was divided into two groups: the artificial reef area (group A) and the natural rocky area (group B).

• 한국수산과학회지
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• 제44권4호
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• pp.366-371
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• 2011

The sea squirt Halocynthia roretzi is mainly cultured in Tongyeong, Southern coastal area of Korea. This study presents the physiological rates of respiration, excretion, feeding and assimilation efficiency of the sea squirt Halocynthia roretzi to analyze the SFG(scope for growth) and net growth efficiency, determined during 2007. Oxygen consumption and nitrogen excretion rates increased with a rise in temperature during the summer period whereas feeding rates decreased. The O:N ratio was high during winter(October to February). Assimilation efficiency showed an annual average of 75.4% during the experimental period, except during a period of elevated temperature in July to September(average $25^{\circ}C$). Net growth efficiency($K_2$) was 8.7 to 64.2% except for May to September, when temperature increased at the aquaculture farm. SFG was negative from May to September, reflecting high temperatures and low feeding rates during this period; its highest positive values occurred during winter.