• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.1
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• pp.1-8
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• 2000

Benthic environments and composition of macrobenthic fauna around the marine fish culture cages were studied to clarify the effect of fish farming near Tongyong from August, 1995 to february, 1996. Sediment grain size and bottom dissolved oxygen under the fish cages were similar to that of a control site, but organic content was higher under the cages. Fewer species were found under the fish cages than under the control site, but conspicuously higher density was obtained under cages. Capitella capitals, Nebalia bipes were dominant infauna, and Asterina pertinifera and Astelias amurensis were dominant epifauna under the fish cage whereas Lumbrineris longifolia and Anphioplus sp. dominated in the control site. Diversity index showed seasonal variation under the fish cages, but showed little variation at the control site. The benthic fauna under the fish cages showed different community structures from the control site. As results, the fish culture cages affected the benthic environment and the community structure of benthic fauna by input of the organic content and biological effects such as dead shells.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.67-68
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• 2000

해상에 시설된 가두리 그물의 경우 강한 흐름이나 파랑에 의하여 그 형상이 변형되며, 이것은 가두리 그물의 저항이 증가되는 것을 방지하고 양식시설의 손실 또는 파손을 방지해 준다. 그러나 가두리 그물의 변형으로 그 용적이 감소되어 가두리 그물 안에 들어 있는 양식어류의 수를 제약할 뿐만 아니라 급격한 용적의 감소는 어체 손상과 유영 행동 등에 영향을 주어 양식 어류 폐사의 원인이 된다. (중략)

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.3
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• pp.190-196
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• 2002

In order to analyze the hydrodynamic forces on fish cage systems, made of frames and nettings, under waves and current, hydraulic model experiments for square type and circular type of fish cage system were carried out in a towing tank. Both cage systems consist of net cages supported by floating frames made of two concentric pipes and four weights hanging from the bottom corners of the nets. There was little difference in the hydrodynamic force on the square type of fish cage system by wave heading under regular waves and the peak frequency of the force on each cage system was in a good agreement with that of induced irregular wave. In addition, it was also observed that the circular type of cage system was more stable to the action of waves and current than the square type.

• The Korean Journal of Malacology
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• v.30 no.1
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• pp.9-15
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• 2014

This study is aimed at figuring out the reasons of the mass mortality of abalone and the increase in its mortality rate in the sea cage. The study suggests that lack seawater circulation in an abalone aquaculture cage is an important culprit for it. We analyzed the current distribution around a 1/20 scaled-down abalone unit cage of 4 rows and 10 columns by fluid flow visualization technique (PIV : Particle Image Velocimetry). The speed of current in the model cage definitely slowed down in the first column of a unit cage. We also observed currents going down to the bottom of a water tank from the unit cages placed in the middle. The speed of wakes behind inside the row in the middle was slower than that outside the row. Water velocity inside and outside a real abalone cage at Nowha Island adjacent to Wan Island was measured to verify results from the tank test. The speed of current in front of the cage by 2 m was 0.11 m/sec while it was only 0.0009 m/sec inside the cage. It had similar findings with those of a tank test.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.1
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• pp.30-34
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• 1988

In roastal fish farms the farmers, especialy engaging in dealing with the floating cage culture, going to know about relationships between holding capacity and water quality in cage. Some of water quality managers and specialists studing physiological ecology understand that the key of water quality management concerned fish farming is budget of dissolved oxygen. This paper deals with oxygen budget in floating cage of the yellow tail farms at southern coastal area in Korea. The sampling station is located at Konli-Do fish farm near Chungmu, and the data is collected for 24 hours from 3:00 p.m. 8th September 1987. In result, the needed oxygen coming after the consumption by the rearing fish had been supplied with the tide current exchange, the sum of oxygen produced by phytoplankton photosynthesis and diffused from atmosphere are no more that $43\%$ for the needs of sea water consumption included respiration of planktons and decomposition of organic matters. The optimum holding capacity of cage is possible to compute with the calculation of minimum diurnal water exchange rate $[Qin{\cdot}V^{-1}\;(C-\bar{c})]$ through net mesh of cage.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.68-69
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• 2003

외해에서 가두리를 이용하여 수산생물을 사육하는 방법은 연안에서 수산생물을 사육하는데 발생하는 해양오염 및 양식 공간의 제약 등 여러 가지 문제를 해결할 수 있는 현실적인 방안으로 인식되고 있다. 하지만, 외해에 부설되는 가두리는 대형의 시스템이며, 그 관리와 수리가 불편하고 외양의 해양환경에 견딜 수 있도록 부설되어야 하기 때문에 어려움이 따른다. (중략)

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.3
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• pp.214-224
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• 2004

A large cage system for the purpose of fishes farming in the open sea was influenced by various forces from the ocean environment. The deformation of the cage by these forces affects the safety of the cage itself, as well as that of the cultivated creatures. In this research, theoretical model was established to analyzing dynamic movement influenced by current for cage. Also, to increase the accuracy of calculations, the reduction ratio of flow speed acquired using the flume tank experiment. Applying the reduction ratio of flow speed to the numerical calculation, the calculation values were compared with the measured values in the flume tank experiment using cage model. The results were as follows ; 1. When the flow speed of the flume tank is fixed, the decrease of the velocity of flow which is passed the upper panel side is proportion to the increase of porosity ratio of netting. 2. When the porosity ratio is fixed, the increase of the velocity of flow which is passed the upper panel side is proportion to the increase of velocity of flow. 3. When the porosity ratio and the flow speed of the flume tank are fixed, the decrease of the velocity of flow which is passed the upper panel side is proportion to the increase of attack angle. 4. As a result of comparison between the underwater shape by simulation which is applying the reduction ratio of flow speed from the experiment using plane netting and that by model experiment, it was found out that the result of the simulation was very close to that of model gear within ${\pm}$ 5 % error range.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.4
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• pp.235-246
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• 2002

The fish farming using net cages has been developed in many semi-closed bays in the southern coast of Korea for the last two decades. The intensive cage cultures of fishes generate considerable amounts of organic waste in the form of uneaten food and faeces. In order to evaluate the effect of fish farming activities we collected the benthic macrofauna near the fish farm area located in Wolho Islet of Gamak Bay and in Haklim Island of Tongyeong in November 1998. Benthic macrofaunal assemblages showed dramatic changes in species number, species diversity, and faunal abundance in the region of the fish farm. These changes were clearly observed even at a distance of up to 30 m from the fish farming cage area. Within 5 m from the cage, there was a zone with low species diversity and highest density, dominated by opportunistic polychaete worm, Capitella capitata. By a distance of 15-30 m, this zone presents highest species number and higher density. Our results clearly demonstrated that fish farm area was highly enriched with organic materials, and implied that the fish farm industry and adjacent benthic ecosystem in semi-closed bay will be seriously damaged by self produced organic wastes in the near future.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.199-200
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• 2000

제주연안은 태풍 및 겨울철 북서풍의 영향으로 일부 항만 내를 제외하고는 가두리가 극미한 실정으로서 광활한 바다의 능동적인 이용을 위하여 해양수산부(해양수산 개발원)의 특정연구개발사업의 일부 지원을 밭아 연구를 수행하였다. 외국의 사례를 보면 북대서양연안의 극심한 해양환경(파고 20m)을 고려한 TLC(Tension Leg Cage) 시스템을 노르웨이 Marintek에서 개발하였으며[1], 일본의 경우는 수심이 깊고 만이 많은 해역을 고려한 부침식 전복 양식시스템을 개발하였고[2], 이스라엘에서는 반잠수식 가두리 양식시스템을 개발하였다[3].(중략)

• Journal of Navigation and Port Research
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• v.30 no.8 s.114
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• pp.721-727
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• 2006

Ammoniac nitrogen excretion is not able to be removed in ocean fish farm. It is the reason for fish being dead in large quantities or declining feeding activity that ammoniac nitrogen is not removed efficiently in ocean fish farm. Because of declining with feeding activity, it is true that feed is wasted for the present. To solve this problem, NH3, one of environment factors in ocean fish farm, monitoring system is suggested to be formed in this paper.