• Title/Summary/Keyword: ARTIFICIAL REEF

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Studies on the Improvement of the Fish Gathering Effects of Artificial Fish Reefs in the Coastal Area of Cheju Island -The Effectiveness of Fishery Resources Enhancement of Artificial Fish Reefs- (제주도연안 인공어초의 집어효과 향상에 관한 연구 - 인공어초의 자원조성효과 -)

  • Ahn, Young-Wha;Rho, Hong-Kil;Kim, Suk-Jong;Jeung, Dong-Gun;Kim, Mun-Kwan
    • Journal of Fisheries and Marine Sciences Education
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    • v.11 no.1
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    • pp.59-68
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    • 1999
  • The effectiveness of fishery resources enhancement of artificial reef settled in the coast of Cheju Island was determined by using the samples collected by scuaba and caught by the trammel net. The obtained results are summarized as follows; 1. Six types of shellfish were found in the artificial reef area, and the amount of shellfish living in that area was $490{\sim}3,483g/m^2$ according to our research. This shows a high density of shellfish in that area. 2. Ten types of seaweeds were found in the artificial reef area, and the reef living in that area was abundant, with $3,556{\sim}10,550g/m^2$. 3. The amount of a catch of fish in the artificial reef area was 3.5~21.4 times more than in the control area. This result shows the high productivity in that area.

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Investigation of Dice Artificial Reef Stability Installed (1981-2004 years) on Pohang Coast of the East Sea (경상북도 포항시 해역에 시설된(1981-2004년) 사각형 어초의 상태조사)

  • Cho, Yong-Chul;Kim, Wan-Ki;Lee, Chae-Sung;Kim, Nam-Il
    • Journal of Advanced Marine Engineering and Technology
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    • v.34 no.1
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    • pp.177-182
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    • 2010
  • Sediment transport around artificial habitat which is induced by the change of flow due to installation of the structure plays a role not only as a defect function of subsidence and burial but also bottom-environment control function. Using Side Scan Sonar (SSS), Differential Global Positioning System (DGPS) and Scuba diving equipment, we investigated a facility condition of a dice reef installed on Pohang coast of the East Sea. Investigation result, at total 139 place, 10,526 dice reef was discovered. As the level which affects function of the above 0.5m, the case 4 place of burial (0.5~1.2m, 2.9%), scour appeared with 3 place (0.5m, 2.2%) and broken was appeared with 183 artificial reefs (1.74%). As a result, dice reef installed Pohang coast appeared to mostly stable.

Behaviors of Artificial Reef Reinforced with Settlement Reduction Reinforcement (침하 저감용 보강재로 보강된 인공어초 설치 지반의 거동 특성)

  • Yun, Daeho;Kim, Yuntae
    • Journal of the Korean Geosynthetics Society
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    • v.18 no.1
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    • pp.1-9
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    • 2019
  • This study investigated settlement and scouring characteristics of artificial reef reinforced with various reinforcement types to reduce settlement and scouring. Three reinforcement types were prepared: geogrid, geogrid-bamboo mat (GBM) and seaweed-pile mat (SPM). Various laboratory tests such as bearing capacity test, large size settlement test, two-dimensional flow scour test were performed according to different soil types (sand, silt, clay). Laboratory test results indicated that bearing capacity of seabed with a reinforced artificial reef increased and its settlement and scour depth reduced for all reinforcement types. Especially, reinforcement effect tends to be greater in clay soft ground rather than sand and silt grounds.

Size determination of Ecklonia cava for successful transplantation onto artificial seaweed reef

  • Kim, Young Dae;Shim, Jung Min;Park, Mi Seon;Hong, Jung-Pyo;Yoo, Hyun Il;Min, Byung Hwa;Jin, Hyung-Joo;Yarish, Charles;Kim, Jang K.
    • ALGAE
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    • v.28 no.4
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    • pp.365-369
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    • 2013
  • The objective of this study was to determine the optimal blade size and timing to transplant seed-stock of Ecklonia cava Kjellman onto the reef structure. We used the modified artificial stepped reef structure. A total of 14 units (3.0 m length ${\times}$ 3.5 m width ${\times}$ 1.1 m height) were deployed 7-8 m deep under the water to examine the optimal blade size and timing to transplant seed-stock of E. cava onto the structures. Sporophytes of E. cava <1 cm in length were all died within 1 month of transplantation. The blades of 5-10 cm in length which were transplanted in March 2007 survived and grew well on the artificial reefs. Growth rates of 5-10 cm size class were higher than those of longer blade sporophytes (20-30 cm size class, transplanted in April) while the survival rates showed no difference between the classes of blade size. Both classes of 5-10 and 20-30 cm in length grew until July, and a reduction in size had occurred in September. These results indicate the importance of the blade size of E. cava and timing for successful transplantation of the seaweed on artificial reef structures.

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.

Experimental study on new artificial reef for hydraulic stability (해조류 이식형 인공어초의 수리적 안정성에 관한 실험적 검토)

  • Shin, Bum-Shick;Chung, Hyun-Joon;Kim, Kyu-Han
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.1
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    • pp.555-560
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    • 2014
  • In Korea, 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 like shellfish reefs, recreational reefs, seaweed reefs as well as fish reefs are beneficial alternatives. This study conducted hydraulic testing to assess the stability of new types of artificial reefs (ARs) constructed to promote the growth of shellfish and seaweed. The results of this study revealed that some dimensionless design parameters affected the stability of new types of artificial reef under various wave and water depth conditions in the fixed bed condition. The findings also highlight the importance of hydraulic experiments in solving problems that have emerged in the design and construction of artificial reefs.

A Study of Artificial Reef Subsidence in Unsteady Flow-Wave Field (비정상 흐름-파랑 공존장의 인공어초 침하특성에 관한 연구)

  • Yun, Sang Jun;Kim, Heon Tae
    • Journal of Ocean Engineering and Technology
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    • v.15 no.3
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    • pp.28-34
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    • 2001
  • The experimental studies for the artificial reef (AFR) subsidence characteristics in the unsteady flow field and in the unsteady flow-wave field were carried out. The difference of scou $r_sidence characteristics between in the steady flow field and in the unsteady flow field wad discussed and also the long-term subsidence characteristics in the unsteady flow field were investigated. AFR subsidence characteristics was discussed with Keulegan - Carpenter number(KC), Reynolds number (Re),. Shields number (Sn) and dimensionless time (t/Tt). And the difference of subsidence characteristics between in the unsteady flow and in the unsteady flow-wave field was discussed.ed.

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A Study of Artificial Reef Subsidence in Unsteady Flow-Wave Field (비정상 흐름-파랑 공존장의 인공어초 침하특성에 관한 연구)

  • Yun, Sang Jun;Kim, Heon Tae
    • Journal of Ocean Engineering and Technology
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    • v.15 no.3
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    • pp.29-29
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    • 2001
  • The experimental studies for the artificial reef (AFR) subsidence characteristics in the unsteady flow field and in the unsteady flow-wave field were carried out. The difference of scour/subsidence characteristics between in the steady flow field and in the unsteady flow field wad discussed and also the long-term subsidence characteristics in the unsteady flow field were investigated. AFR subsidence characteristics was discussed with Keulegan - Carpenter number(KC), Reynolds number (Re),. Shields number (Sn) and dimensionless time (t/Tt). And the difference of subsidence characteristics between in the unsteady flow and in the unsteady flow-wave field was discussed.

A Study of Artificial Reef Subsidence in Unsteady Flow Field (비정상 흐름장의 인공어초 침하특성에 관한 실험적 연구)

  • 김헌태
    • Journal of Ocean Engineering and Technology
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    • v.15 no.2
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    • pp.33-38
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    • 2001
  • The subsidence characteristics of artificial reef (AFR) in the unsteady flow such as tidal flow were investigated. The scour and subsidence characteristics were confirmed in the steady flow field. In a main study, the interaction of "Flow - Sediment Movement - Structure Behavior" and scou $r_sidence mechanism were discussed int he unsteady flow field. AFR subsidence characteristics was discussed with Reynolds number(Re*), Shields number(Sn*), dimensionless acceleration of flow (af/g) and dimensionless time (t/T). Most of all, the continuous AFR subsidence from the scour was occurred by periodic behavior of AFR. This behavior is result from the asymmetric ground, and is influenced by maximum velocity, duration time and direction of flow.ow.

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Calculation of the Coefficient of Artificial Reef According to the Coefficient of Volume (체적계수에 따른 인공어초 계수산정)

  • Kim, Young Jong;Choi, Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.9
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    • pp.2307-2312
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    • 2014
  • Artificial reef refers to various structures that facility to construction field format and spawning of marine organisms, sea ranch, forest of the sea, and sea jungle artificially in water, Build a production stable base of marine products, thereby contributing to an increase in the income of fishermen. In the management of an artificial reef, the calculation of the number of square reefs may be that it is a method to perform the submersible is an important part of maintenance is correct. However, cost and diving personnel, depending on the diving situation, there is a difficult thing to implement to coast across the country. Therefore, In this study, We calculated the volume using the multi-beam Echo Sounder and side scan sonar for the reefs of the rectangle are the existing installation. And proposes the improvement of the estimation in accordance with the volume coefficient reef.