• Title/Summary/Keyword: Artificial reefs

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The Hydraulic Characteristics of Artificial Reefs Used to Construct Seaweed Beds (해중림 조성을 위한 어초의 수리학적 특성)

  • Sohn, Byung-Kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.3
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    • pp.215-220
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    • 2008
  • This study examined the stability of cross- and box-type artificial reefs used to construct seaweed beds. Theoretical and experimental studies have clarified the Froude similitude. However, basic data needed to develop a more stable design for artificial reefs must be collected from long-term studies and analyses of sliding caused by waves. Hydraulic experiments are important for solving problems in the design and construction of artificial reefs. This study examined some design parameters for artificial reefs under wave and currents. The results showed the stability of cross- and box-type artificial reefs for constructing seaweed beds using a dimensionless parameter (the surf similarity parameter), water particle velocity, and so on. The hydraulics experiment indicated that the stability of artificial reefs differed according to their method of installation. This implies that artificial reefs should be installed after considering various environmental factors, such as wave breaking, reflection, and sediments.

Management after installation of artificial reefs;Present Condition and Development Scheme (인공어초 사후관리 현황과 발전방향)

  • Lee, Sung-Il;Ahn, Seung-Hwan;Kim, Dong-Sun
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.11a
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    • pp.160-161
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    • 2005
  • It is important to manage artificial fish reefs with installation for restoration. The instruments of survey for artificial reefs condition(location, amount etc.) is Side Scan Sonar and Multi-beam sonar. The efficient and economic survey of the artificial reefs facility is the complete survey of the SSS(Side Scan Sonar) in all area first and then the survey of the artificial reefs by MBES(Multi Beam Echo Sounder) in the finding area.

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An Experimental Study on the Stability of Artificial Reefs for Shellfish and Seaweed (패조류용 어초의 안정성에 관한 실험적 연구)

  • Sohn, Byung-Kyu
    • Journal of Ocean Engineering and Technology
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    • v.21 no.6
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    • pp.120-124
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    • 2007
  • The purpose of this study was to investigate the stability of the arched and fan types of artificial reefs, which provide habitats for shellfish and seaweed. According to the Froude similitude, parameters affecting the stability of the artificial reefs were analytically, experimentally studied. First, the design parameters of the artificial reefs in wave and current fields were presented. Then, using dimensionless parameters, such as the surf similarity parameter and water particle speed, the stability of the arched and fan types of artificial reefs was investigated. From the hydraulic experiments, it is shown that the stability heavily depends on the way the artificial reefs are installed. Therefore, the installation of the artificial reefs on the surf zone should be carefully executed.

An Experimental Study on Development of Artificial Reefs Using Volcanic Stones for Marine Forests (용암석을 사용한 해중림 조성용 인공 조초 개발에 관한 실험적 연구)

  • Hong, Chong-Hyun;Ghoa, Jong-Hun
    • Journal of Ocean Engineering and Technology
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    • v.22 no.3
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    • pp.103-108
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    • 2008
  • Topics discussed in this paper are engineering design of artificial reefs, design considerations of compressive strength and pH, materials of silica fume concrete and volcanic stones for reef construction, and field monitoring of artificial reefs. Six artificial reefs were deployed offshore at Biyangdo in July 2006, and succession patterns on the reefs were investigated bimonthly from July 2006 to October 2007. The spore-bag method, which has been widely used in Korea for the attachment of seaweed on artificial reefs, was applied to the developed reefs using the kelp Ecklonia cava, which is the dominant species in Jeju, and recruitment and growth patterns were observed.

A Study on the Economic Effects of Artificial Reefs -In Case of Suwoo-do Artificial Reefs- (인공어초시설사업의 경제적 효과에 관한 연구 -수우도 인공어초어장을 중심으로-)

  • 유정곤;이승우;황진욱
    • The Journal of Fisheries Business Administration
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    • v.29 no.2
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    • pp.177-197
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    • 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.

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The application of GIS in analyzing acoustical and multidimensional data related to artificial reefs ground (인공어초 어장에서 수록한 음향학적 다차원 데이터 해석을 위한 GIS의 응용)

  • Kang, Myoung-Hee;Nakamura, Takeshi;Hamano, Akira
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.3
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    • pp.222-233
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    • 2011
  • This study is for the multi-dimensional analysis of diverse data sets for artificial reefs off the coast of Shimonoseki, Yamaguchi prefecture, Japan. Various data sets recorded in artificial reefs ground were integrated in new GIS software: to reveal the relationships between water temperature and fish schools; to visualize the quantitative connection between the reefs and the fish schools; and to compare the seabed types derived from two different data sources. The results obtained suggest that the application of GIS in analyzing multi-dimensional data is a better way to understand the characteristics of fish schools and environmental information around artificial reefs and particularly in the evaluation of the effectiveness of artificial reefs.

Fishes distribution and their connection to artificial reefs off Bukchon, Jeju Island using geographic information system (지리정보시스템을 활용한 제주도 북촌의 인공어초해역에서 어류 분포와 어초와의 관계)

  • KANG, Myounghee;FAJARYANTI, Rina;JUNG, Bongkyu;YOON, Eun-A;MIN, Eunbi;LEE, Kyounghoon;OH, Woo-Seok;PARK, Geunchang;SHIN, Young-Jae;CHOI, Yong-Suk;YI, Byung-Ho;HWANG, Doojin
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.2
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    • pp.121-128
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    • 2019
  • Various artificial reefs provide the fish habitat and nursery, and contribute the improvement of fisheries productivity. The evaluation methods of fishery resources in the artificial reefs have been done by fishing, scuba diving, underwater camera, and scientific echo sounder/sonar. There are a number of studies using echosounders on the quantitative and qualitative evaluations of artificial reefs in various seas around the world. This study focused on the spatial distribution of fishes around artificial reefs and the influential area of reefs off Bukchon, Jeju Island. Not only acoustic data but also various properties of artificial reefs were used in the geographic information system to extract relevant results. As a result, the major material of reefs on this study site was concrete and the number of reefs with that material was the most. The volume of reefs consisted of steel only and steel with riprap was considerably large compared to other reefs. The average NASC in the vertical distribution of fishes in artificial reefs was $31.6m^2/nm^2$ in April, and that was $61.3m^2/nm^2$ in June. The distance between the fish school and their nearest reef in June morning had a wide range from 750 to 3250 m. On the basis of the influence ray of artificial reefs, it had a tendancy of NASC to decrease with distance from the reef in the June morning. It is a preliminary study to present the geospatial analysis example to understand a better way of comprehensive artificial reef environments.

The maintenance technology and their improvement of artificial reef fishing grounds (인공어초어장 관리조사기술의 현상과 개선방안)

  • Kim, Chang-Gil;Kim, Ho-Sang;Seo, Jang-Woo;Kim, Doo-Bong
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.11a
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    • pp.140-141
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    • 2005
  • This study describes the postinstallation maintenance technology of artificial reefs and their improvement. The maintenance technology of artificial reefs consists of four steps; the investigation of volumes of installed reefs, the removal of fishing gears entangled in reefs, the estimation of reef functions, and the establishment of surveyed results in the data base. The proper understandings of their steps is the key to improve the maintenance technology of artificial reefs.

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Hydraulic model test for corrugated artificial reef stability (수리실험을 통한 요철형 인공어초 안정성 검토)

  • Baek, Seung Hwa;Shin, Bum-Shick;Kim, Kyu-Han
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.8
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    • pp.5327-5332
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    • 2014
  • In Korea, the quantitative growth rate of artificial reef construction is supposed to reach the peak point. Therefore, new approach is needed to the point of artificial reefs business. Functional reefs, such as shellfish reefs, recreational reefs, seaweed reefs, and fish reefs, are beneficial alternatives. This study conducted hydraulic testing to assess the stability of corrugated artificial reefs (ARs) that were constructed to promote the growth of shellfish and seaweed. The results of this study showed that some dimensionless design parameters affected the stability of corrugated artificial reefs under a range of wave and water depth conditions in a fixed bed condition. The findings also highlight the importance of hydraulic experiments in solving the problems that have emerged in the design and construction of artificial reefs.

Acoustic Tracking of Fish Movements in an Artificial Reef Area Using a Split-beam Echo Sounder, Side-scan and Imaging Sonars at Suyeong Man, Busan, Korea (수영만 인공어초 해역에서 소너에 의한 어군의 유영행동 추적)

  • Lee, Dae-Jae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.3
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    • pp.273-281
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    • 2013
  • The movement patterns of fish aggregations swimming freely near artificial reefs on August 24, 2006, at Suyeong Man, Busan, Korea, were acoustically investigated and analyzed. Acoustic surveys were conducted using a 70kHz split-beam echo sounder, 330 kHz side-scan sonar and a 310 kHz imaging sonar. Algorithms for tracking the movement of fish aggregations swimming in response to artificial reefs were developed. The travel direction and the swimming speed for two aggregations of fish were estimated from the trajectory orientations of echo responses recorded by the imaging sonar.The first group was floating just above the reef structure, while remaining in the midwater column, and the second group was swimming through and around artificial reefs near the seabed. The mean swimming speed was estimated to be 0.40 m/s for the midwater fish aggregation and 0.17 m/s for the bottom aggregation close to artificial reefs. These results suggest that the swimming behavior of fish aggregations passing close to artificial reefs near the seabed displayed a slower moving pattern than fish floating just above the reef structure in the midwater column.