• Journal of Ocean Engineering and Technology
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• v.35 no.1
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• pp.75-81
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• 2021

Artificial Coral Reefs (ACRs) have been introduced to help solve coastal erosion problems, but their feasibility has not been assessed with field data. This study conducted a feasibility analysis of ACRs on their erosion mitigation effects by performing a case study of Cheonjin-Bongpo beach, South Korea. A numerical-physical combined analysis was carried out using a SWAN model simulation and physical model test with a scale of 1/25 based on field observations of Cheonjin-Bongpo beach. Both Dean's parameter and the surf-scaling parameter were applied to comparative analysis between the absence and presence conditions of the ACR. The results for this combined method indicate that ACR attenuates the wave height significantly (59~71%). Furthermore, ACR helps decrease the mass flux (~50%), undertow (~80%), and maximum wave set up (~61%). The decreases in Dean's parameter (~66%) and the surf-scaling parameter suggest that the wave properties changed from the dissipative type to the reflective type even under high wave conditions. Consequently, an ACR can enhance shoreline stability.

• Journal of Practical Agriculture & Fisheries Research
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• v.17 no.1
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• pp.45-56
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• 2015

The distribution of seaweed was examined in Jeonnam archipelago marine ranching area, the coastal of geumo-do, Yosu. Abundance and distribution of seaweed in dropping site of artificial reef were sampled at 6 station at October 2007. Seaweed community were investigated with quadrat method at line-transect by scientific SCUBA divers. as a result, 30 species in total, 4 green, 9 brown and 15 red seaweed were identified. Range of seaweed biomass in all sampling stations were about 1,600~4,000 g/m². At intertidal zone, appearance of individuals and dominance rate were showed higher than below the subtidal line and at depth from 4m to 6m, individuals, dominance rate and biomass were represented low level. characteristic of water in marine ranching area is turbidity and also compensation depth is low. For that reason, individuals of seaweed community were smaller from depth of 4 meters. Therefore, when equip the artificial reef for preparation of seaweed beds need consider that equipment periods(early spring; before releasing marine seaweed spore) and suitable water depth(3~6m).

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.4
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• pp.1042-1056
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• 2016

To evaluate the wake regions of six artificial reefs (ARs) frequently used in the marine forest creation project in Korea, we consider the effect of water flow directions on the wake regions and accordingly propose a wake region diagram, which is characterized by parameters such as wake volume fluctuations, averaged wake volume, fundamental symmetric angle, secure angle, and principal direction. To demonstrate the parameters, seven water flow directions (0 to $90^{\circ}$) were considered and consequently the variations in wake volumes were investigated by using the concept of wake volume, adopting element-based finite volume method, and utilizing numerical flow domain and boundary conditions. From the analysis results, it was shown that the wake region diagrams have a period of either 45 or $90^{\circ}$ according to the geometrical symmetry of each artificial reef. Also, it was found that the secure angle ranges fluctuate depending on the shapes and sizes of the artificial reefs considered. Thus, it is demanded to consider those parameters during installation of artificial reefs for establishing a larger wake region and accordingly attracting more marine fauna and flora in the region.

• Magazine of the Korea Concrete Institute
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• v.14 no.6
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• pp.72-79
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• 2002

최근 산업기술의 고도화와 함께 임해공업단지 조성으로 연안매립이 활발하게 이루어져 왔으며, 그 외에도 매립 간척사업이 용이한 연안해역은 국토확장사업으로 점차 육지화 되고 있다. 또한 해양오염의 악화, 각국 200 해리 경제수역의 설정으로 인한 원양어업 위축, 어업장비의 현대화 및 대형화로 인한 남획으로 연근해 수산자원은 심각하게 고갈되어 가고 있는 실정이다.(중략)

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2001.08a
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• pp.163-171
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• 2001

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.8
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• pp.1275-1280
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• 2009

Tidal currents were observed at 1 station of artificial reefs group during 15days. Maximum current was 82.4cm/s, and mean current showed 12.8~28.0cm/s, respectively. Flood currents magnitude were bigger than ebb ones due to wake region. To grasp sediment distributions, sediments were sampled at 4-direction(E, W, S, N) around each station. According to the results of sample analysis, sediments showed different distribution by main current direction. It showed that sediments distribution at front and back of artificial reefs were differently occurred by change of main current direction. It suggest that artificial reefs need to install after confirming tidal currents direction and sediments type.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.537-544
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• 2018

In this study, a simple, efficient, user-based program called SCAR was developed for evaluating the sliding and collapse of artificial reefs due to hydrodynamic forces in ocean environments. SCAR was developed by applying Delphi code and a Graphical User Interface (GUI) based on the Morison formula for evaluating and analyzing the stability of artificial reefs. SCAR can be applied widely for design and stability evaluation of fishery structures (such as artificial reefs or other underwater structures) in undergraduate and graduate courses and by experts in the field.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.230-238
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• 2003

An effect on the enhancing production of hollow 'jumbo' structures and the condition of artificial reefs (dice and hollow jumbo structure) by side scan sonar were described. The experiment of the capture of fish in the jumbo structures and control site (non-artificial site) by trammel net and traps was done twice every year from 1998 to 2000. The relative catches by trammel net between in the jumbo structure and in the control site was significantly different in number and in weight at 5% level and also that by traps significantly different in weight. The t-test of the catch of finespotted flounder showed that the hollow jumbo structure was regarded as a breeding field because the average size of the flounder in the jumbo site was smaller than that in the control site. The search on the condition of the artificial reefs (dice and hollow jumbo structure) was performed by side scanning sonar which showed various phase of it such as accumulated, dispersed, scouring and partly buried. The result implied that in the area of sand bottom with strong tide like the western sea of Korea, the current criterion for constructing artificial reef should be modified because of the sand moving on the bottom.

• Journal of Fisheries and Marine Sciences Education
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• v.13 no.2
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• pp.146-167
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• 2001

Korea and China are two opposite countries located aside Yellow Sea and co-utilize the East China Sea. The two countries are close together from geological point of view, however, the competitive development of resources was more emphasized than the cooperative development of resources between the two countries because the special policy relationship. Additionally, after the communist government of China was founded in 1949, the political conception between the two countries was quite different. Therefore the establishment of appropriate international fisheries co-operation was impossible, and the international management problems of fisheries resources in Yellow Sea and East China Sea were let alone. UN convention on the Law of the Sea came to force in 1994, Korea and China adopted the exclusive economic zone system in 1996. On the other hand, Fisheries Law in Korea was enacted in 1953 in order to management of fisheries resources, and also China was enacted fisheries law in 1986. The two countries control the fisheries effort through fisheries license system, meanwhile through prohibition fishing area, prohibition fishing period, limitation of net size, and limitation of body length to conserve and manage the fisheries resource. The serious management methods of resource management in the two countries are similar such as the creation of promptly decreased species and those species that have commercial value, discharge of fish seedling stock, settlement of artificial reef and clean of fishing ground. Therefore, the two countries should consider not only the improvement of formal law system, but also how to recover the fisheries resources in circumference water zone and how to improve the efficiency of fisheries resource management. Specially the settlement and management of artificial reef should be chosen in the area that have the highest benefit to two countries, and should establish the common management system of discharge of fish seedling stock. And the two countries should adopt the same criteria through technical management and limitation of net size, limitation of body length, and prohibition area of special fisheries to ensure the highest fisheries benefit of fisherman in the two countries and the highest efficiency of fisheries resource management.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.2
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• pp.359-364
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• 2008

Using multi beam echo sounder, side scan sonar and scuba diving equipment, ceramic type, uneven type and semicircle-ramus type reefs into sandy bottom were ascertained, the depth of submersion in 7.2-10.3m on the coast of Gangneung, East of Korea, forty uneven type artificial reefs(AR) were totally buried into the sandy bottom. Two of five semicircle-ramus type ARs had only of their top area exposed. For most of the 45 ceramic reefs, only the upper 25-150cm of ARs were visible. The burial pattern is different in west and east side of the reefs, where the east side is deeply buried compared to the west side. From these results. it is recommended that sufficient analysis of bottom structure and materials especially in the sandy sea area should be undertaken in order to determine the best type of artificial reefs to be deployed and the best location for depoloyment.