• The Journal of Fisheries Business Administration
• /
• v.29 no.2
• /
• pp.177-197
• /
• 1998

Korean fisheries industry is surrounding by domestic and international difficulties due to the effectuation of the UN Convention on the Law of the Sea and declaration by many coastal states of 200-mile Exclusive Economic Zone and acceleration of ocean pollution in global recognition increasing of the importance of the ocean Resource enhancement policy in Korea fisheries industry is very important strategy fer the fostering of the fisheries resource and proper conservation and management of the coastal and off-shore living marine. Among resource enhancement policy, artificial reefs project has been the most effective strategy. The objectives of this paper are to find the economic effects of artificial reefs. The sampling artificial reefs is constructed at Suiido with 6~7m height. In order to analyze the fishing effect of artificial reefs, a few research have been conducted since 1975. For these analysis focuses on the side of scientific effect of artificial reefs, we analyzed on the side of economic effect. The results of the economic effects of artificial reefs are as follows ; First, the fishing effect analysis by using the NPV method in artificial reefs of Suiido ground prove to be economic feasibility. Second, the major socio-economic effect from artificial reefs include the increasing of recreation fishing, maintenance of fishing community, protection illegal fishing, conservation of coastal environment, and enlargement of advanced fisheries supply. Based on the above results, we conclude that artificial reefs project not only contributes to the welfare of fishermen by increasing of economic income, but enlarges to socio-economic gains by protection of illegal fishing and conservation coastal environment and so on.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.43 no.2
• /
• pp.126-139
• /
• 2007

In the autumn of 2000 and spring of 2001, field surveys were conducted to estimate the effectiveness of artificial reefs (type cube, $2{\times}2{\times}2m^3$) that were established in the four islands of Bangnyeong, Socheong, Daeyeonpyeong and Ganghwa in Kyonggi Bay, the west coast of Korea during 1995 and 1996. The condition of reefs was examined through SCUBA diving and a side-scan sonar. Much of the reefs in Daeyeonpyeong and Ganghwa area were buried in bottom sediment. Despite an intensive search in Bangnyeong area, even a cluster of reefs was not found and most of them seemed to be buried by sand waves. Thus an appropriate investigation on the sediment transport should be included in pre-assessment for the expected performance and protection of artificial reefs. Distribution of average CPUE in natural fishing ground (control) was estimated by bootstrapping simulation and possible comparison of CPUE between control and reef areas (treatment) were made in Bangnyeong and Socheong (Experiment I). Positive reef effect was detected in Socheong but CPUE of treatment in Bangnyeong was varied between or lower than the 99% CPUE confidence intervals of the control. Control/treatment abundance and biomass of fishes and invertebrates were tested by paired t-test and sign test (Experiment II). Only four cases among 22 showed significant positive effect. Based on the results, the cube artificial reef in Socheong was inferred as an affirmative one. Floor type was hypothesized to be one of the probable agents in determining the effectiveness of artificial reefs.

• The Journal of Fisheries Business Administration
• /
• v.44 no.3
• /
• pp.29-46
• /
• 2013

The purpose of this study is to evaluate the economic validity of artificial reefs facilities and seeds release programs in Jeju Trial Sea Farm Project for raising fishing people's revenue. The results of this study show the artificial reefs facilities and seeds release programs have net present value of 15,962.63 million won, internal rate of retrurn 13.86%, and benefit-cost of 1.912 under a 5.5% social discount rate. This suggests that in Jeju trial sea farm project, artificial reefs facilities and seeds release programs increase fisherperson's revenue.

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

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.47 no.2
• /
• pp.139-145
• /
• 2011

Hydro-acoustic survey was carried out to estimate a fish distribution at marine ranching area and aggregated fish schools at artificial reef area in Oeyeondo, Korea. The survey system was set up with DGPS system, scientific echo sounder (EK60, Simrad Co.), and ECDIS (Mecys. Co. LTD). A track survey and a random survey was respectively applied to the marine ranching area (474.4ha) and to the artificial reef area (within a radius of 300m). As the result, fish distribution and MVBS values in marine ranching area showed that created fisheries resources didn't come to be abundant yet as to appear fish distribution in all of the area. In the artificial reef area, it was, however, able to detect many fish school signals on the top of and around artificial reefs and to confirm the luring effect of artificial reefs.

• Resources Recycling
• /
• v.16 no.5
• /
• pp.19-24
• /
• 2007

Reefs are the marine structure that can give resting, inhabiting, feeding and nursing spaces for a variety of fishes. Usually artificial reefs are made of cement and steels respectively in Japan as well as in Korea. However since resources deficiency has been getting serious, other materials are taken into consideration for the basic bodies of artificial reefs. About 300 thousand tons of waste agricultural plastic films are generated every yew in Korea, but no effective recycling techniques have been developed. In this sense, artificial reefs made of waste agricultural plastic films are the most representative symbol of the recycled products in the Resource Recycling Era. In particular, since these reefs could be made of the semi-cleaned waste agricultural plastic films that still contain high portion of soil, it is very environmentally friendly not only in manufacturing process but also in using under water. Furthermore they have some evident advantages as follows; 1) high fish swarming effect 2) good initial attachment of the marine growths 3) extremely low corrosion to brine 4) easy adjustment of the gravity 5) economical manufacture, transportation and jettison 6) excellent safety to ecosystem caused by lower elution of toxic substances 7) good recyclable property after application and so on.

• Journal of Ocean Engineering and Technology
• /
• v.18 no.1
• /
• pp.53-62
• /
• 2004

The Purpose of this study is to recycle the waste concrete, which is generated in huge quantities, from construction works. in order to achieve this goal, it is important to determine the compressive strength, workability, slump, and ultrasonic velocity of recycled aggregate concrete. Thus, several experiment parameters are considered, such as water-cement ratios, sand percentage, and fine aggregate composition ratios, in order to apply the recycled aggregate concrete to pre-cast artificial fishing reefs. From the results, it has been shown that the proper mix designs for reef concrete are W/C=45%, S/a=50%, SR50:SN50 in recycled sand and natural sand mix combination case, W/C=45%, S/a=50%, SC50:SN50 in crushed sand and natural sand mix combination case, W/C=45%, S/a=50%, SR50:SC50 in recycled sand and crushd sand mix combination case. Also, this study shows that the shape and surface roughness of fine aggregate particles have an effect on the strength, slump, ultrasonic velocity of tested concrete, and the compressive strength ratios of 7days' and 90days' curing ages of recycled aggregate concrete are about 70% and 110% of 28days' curing age.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.11a
• /
• pp.159-166
• /
• 2004

The beach, a margin between the sea and the land, is an extremely dynamic zone, for it is here that the motion of the sea interacts with the sediment, rock of the land or the artificial barriers. In order to prohibit or retard erosions due to the extreme Typhoon or storm induced waves, man has constructed these of temporary or more permanent nature, but they caused problems of other erosions from the secondary effect of them and a bad influence on the seascape. In considering the energy available to accelerate sediment transport and erosion in the surf zone, where the waves are broken, and offshore beyond the breaker line, the wave height and the wave period should be taken account. Hence, we tried to present an applicability of the submerged artificial Bio-reefs analyzing waves by a numerical model such that they could reduce the wave power without the secondary effect and restoration of marine ecologies. A new technique of beach preservation is by artificial reefs with artificial and/or natural kelps or sea plants. By engineering the geometry of the nearshore reef, the wave attenuation ability of the feature can be optimized Higher, wider and longer reefs provide the greatest barrier against wave energy but material volumes, navigation hazards, placement methods and other factors require engineering considerations for the overall design of the nearshore reefs.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.47 no.2
• /
• pp.146-152
• /
• 2011

Underwater CCTV camera systems are increasingly replaced the traditional net approach of assessing the species, numbers and aggregation patterns of marine animals distributing around the artificial reefs installed in the inshore fishing grounds, in particular, in relation to the biological investigation of behavior and distribution patterns of target fishes. In relation to these needs, we developed a multi-directional underwater CCTV camera system to use in detecting and tracking marine animals in the artificial reef ground. The marine targets to be investigated were independently tracked by using a camera module toward the bottom and four camera modules installed in the interval of $90^{\circ}$ in horizontal plane and inclination of $45^{\circ}$ in vertical plane of the CCTV system without the overlap of video frames by each camera module. From the results of several field tests at sea, we believe that the developed multi-directional underwater CCTV camera system will contribute to a better understanding in evaluating the effect of artificial reefs installed in the inshore fishing grounds.

• Journal of Fisheries and Marine Sciences Education
• /
• v.12 no.1
• /
• pp.11-21
• /
• 2000

Most of artificial reefs in the examined areas were normally established except for some lower parts demersed slightly, and some to function. 1) Twenty species of fish were captured by fishing gear, and 10 species were observed by scuba in the examined areas. 2) Five algal and five fisheries animal species were observed as fouling organism. 3) C.P.U.E of trap, long liner and gill netter in the examined areas was respectively 2.12, 10.23, and 4.93, where as that in contral was established as 1.41, 4.43 and 2.86. 4) Species composition by the fishing gear the trap, long liner and gill netter in the examind areas was respectively 94, 85 and 118, where as that in control was established as 58, 37 and 62. Accordingly, The fishing effects in the artificial reefs installation sector was two times higher than comparative sector.