• Title/Summary/Keyword: Reefs

Search Result 193, Processing Time 0.027 seconds

Development of WIPI-based Artificial Reefs Search Contents (WIPI기반 인공어초 검색 콘텐츠 개발)

  • Kwak Ho-Young;Han Kyoung-Bok
    • The Journal of the Korea Contents Association
    • /
    • v.5 no.5
    • /
    • pp.238-247
    • /
    • 2005
  • The development of IT related technology has made it possible to offer 'Any Time, Any Where, Any Service' to the users and internet-based service became accessible while on the move through wireless internet service. Moreover, the development of various wireless contents has been provided diverse ioy and convenience to life. However, the existing wireless contents had been subordinate to the wireless internet platform because it had not been set up for a standardized environment. Therefore, repeated developments of contents have been causing waste of resource, time and manpower. This paper aims at suggesting WIPI-bases artificial reefs search contents which have become independent from platform by using JAVA. Artificial reefs facilities are a government project for increasing the revenue of fishermen but only few fishermen know the information about the location of artificial reefs and most of them are not aware of the location of these facilities. There(ore this thesis plans to develop WIPI-bases artificial reefs search contents to provide information such as the location, the depth, and the bottom material to anglers and those fishermen who do not know the location of artificial reefs so that the fishermen can have the opportunity to increase their revenue and also the opportunity to catch a big fish for anglers.

  • PDF

Biak and Wakatobi reefs are the two hottest hotspots of coral reef fish diversity and abundance in the Indonesian Archipelago

  • Imam Bachtiar;Edwin Jefri;Muhammad Abrar;Tri Aryono Hadi
    • Fisheries and Aquatic Sciences
    • /
    • v.25 no.11
    • /
    • pp.549-558
    • /
    • 2022
  • The Indonesian Archipelago has a very complex geological history, along with equatorial warm sea temperature, resulting in diverse types of coral reefs and high diversity of coral reef fish. Many livelihoods of the coastal community are dependent on coral reef fisheries. The present study aimed to determine which region and location in the Indonesian Archipelago has the most diverse and abundant coral reef fish. The archipelago was divided into four regions: the Indian Ocean, Sunda Shelf, Wallacea, and the Pacific Ocean. Data were obtained from a national coral reef monitoring program of the Indonesian Research Center for Oceanography (RCO)-the National Board for Research and Innovation (BRIN). The reef fish data were collected using the underwater visual census method, from 321 belt transects on 24 locations (districts) across the archipelago. The results show that coral reef fish diversity of the Pacific region was the highest across the archipelago for all three trophic levels, i.e., corallivore, herbivore, and carnivore fish. The Pacific Ocean region also had the highest fish abundance for the three trophic levels. Comparison among locations revealed that the best ten locations in reef fish diversity and abundance were Sabang, Mentawai, Makassar, Selayar, Buton, Luwuk, Ternate, Raja Ampat, Biak, and Wakatobi. Wakatobi reefs showed their supremacy in carnivore fish diversity and abundance, while Biak reefs were the best in herbivore fish. The abundance of corallivore fish was also considerably high in Sabang reefs, but it is still lower than in Raja Ampat, Biak, and Wakatobi reefs. These results provide empirical evidence that the coral reefs of Wakatobi and Biak are the hottest hotspots of coral reef fish diversity and abundance in the Indonesian Archipelago.

Seaweed Succession on Artificial Reefs Placed in Different Depths at Ikata, Japan

  • Choi Chang Geun;Ohno Masao;Sohn Chul Hyun
    • Fisheries and Aquatic Sciences
    • /
    • v.5 no.4
    • /
    • pp.281-286
    • /
    • 2002
  • Artificial reefs were set on a sandy bottom substratum at 8m, 10m and 13m depths along the coast in Muronohana, Ikata, Japan. Succession of seaweed communities was observed monthly or bimonthly from February 1999 to August 2000 on artificial reefs. Within one month, the diatom colonized on the reefs with coverage of $100\%$. After three months, Enteromorpha intestinalis and Colpomenia sinuosa dominated on the reef in the spring. Seaweed flora decreased during the summer and the dominant species were several species of Melobesioidea. In the winter, the seaweeds grew up again and the dominant species on the each reef were Sargassum spp., Ecklonia kurome and Padina arborescens after one year. The dominant species in the algal succession process changed from diatoms to the perennial seaweeds such as Sargassum spp., E. kurome and P. arborescens. Thus, the pattern of succession of the dominant species and the degree of domination were changed by the season, water depth and the recruitment of spores and eggs from the mature alga around the reefs.

Monitoring of Fish Aggregations Responding to Artificial Reefs Using a Split-beam Echo Sounder, Side-scan Sonar, and an Underwater CCTV Camera System at Suyeong Man, Busan, Korea (소너 및 수중 CCTV 카메라 시스템을 이용한 수영만 인공어초 주변에 군집한 어군의 모니터링)

  • Lee, Dae-Jae
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.46 no.3
    • /
    • pp.266-272
    • /
    • 2013
  • The objective of this study was to monitor and evaluate the schooling characteristics, including the distribution density (volume backscattering strength) and acoustic size (target strength), of commercially valuable species swimming in response to artificial reefs installed at Suyeong Man, Busan, Korea. Fish aggregations at two artificial reef areas and at a nearby natural rocky reef habitat were recorded and analyzed using a 70 kHz split-beam echo sounder and 330 kHz side-scan sonar from August to September, 2006. An underwater CCTV camera system was also used to observe marine organisms in physical contact with and swimming very close to artificial reefs. During the acoustic observations at three reef sites, useful information about schooling characteristics of fish aggregations responding to artificial reefs were obtained, but more trials are needed to confirm significant differences in schooling behavior and geographical distributions in areas containing natural reef structures and artificial reefs.

A Study on the Characteristics of Wave Forces on Artificial Reefs (착저식 인공어초에 작용하는 파력특성에 관한 연구)

  • RYU Cheong-Ro;KIM Hyeon-Ju
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.27 no.5
    • /
    • pp.605-612
    • /
    • 1994
  • The methods to determine the hydrodynamic coefficients for the fixed type artificial reefs which were constructed to control ecological system in coastal waters are compared and discussed by model test results. To calculate the wave forces, least square method show good agreement with the experimental results and more stability than maximum force component method or Fourier decomposition method. This modified least square method of weighting the square of measured force turned out to be the most feasible method for maximum force. Using the feasible method, hydrodynamic characteristics for artificial reefs on uniform slopes offshore and breaking zone were studied. They were properly related to Keulegan-Carpenter's number and found larger than previous results. Wave force coefficients for artificial reefs around breaking zone were distributed from 1.5 to 2.5, and the mean value was 2.0. Drag force components were more in evidence than inertia force in maximum force which is important parameter to evaluate stability for high-permeability structures. A formula for the calculation of the maximum force for artificial reefs design is proposed, using structural dimension, water particle velocity and Keulegan-Carpenter's number.

  • PDF

Wake Region Estimation of Artificial Reefs using Wake Volume Diagrams (후류체적선도를 이용한 인공어초 후류역 평가)

  • KIM, Dongha;JUNG, Somi;NA, Won-Bae
    • 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.

The Estimation and Economic Evaluation of Fisheries Benefit in Jeju Trial Sea Farm Project (제주 시범바다목장사업의 어업편익 추정과 경제성 평가)

  • Kang, Seok-Kyu
    • 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.

Settlement Characteristics of Square Reefs installed on Soft Seafloor Ground (전남 고흥해역 연성지반의 인공어초의 침하 연구)

  • Kim, Dae-Kweon;Suh, Sung-Ho;Cho, Jae-Kwon;Kim, Chang-Gil;Choi, Im-Ho;Kim, Byoung-Sub
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.34 no.1
    • /
    • pp.163-167
    • /
    • 2010
  • Square reefs of 2 groups installed at 1984 on mud and sandy-mud seafloor were compared with settlment conditions of those at Goheong coastal in middle-south sea of Korea at 2007. Reefs installed on mud and sandy-mud seafloor were settled to 1.9m and 2.4m, respectively. It suggest that a function of square reefs group installed on soft seafloor decrease over 50% after 20 years.

Effects of artificial reefs for the nursery ground on fishery resources in the shallow waters

  • Park, Chang-Geun;Masao Ohno;Sohn, Chul-Hyun
    • Proceedings of the Korean Society of Fisheries Technology Conference
    • /
    • 2000.10a
    • /
    • pp.243-243
    • /
    • 2000
  • There are a large number of researches concerning about artificial reefs in Japan, and many Japanese companies have developed and specialized in the coastal engineering in recent years. Various shape, size and material of artificial reefs are constructed, however, concrete and steel structures are popular material in Japan. Five kinds of artificial reefs were put down on gravel bottoms 5-10 m deep in February 1999, which is located 100 m off Ikata, Shikoku, southern part of Japan. (omitted)

  • PDF

Hydraulic Characteristics of Two Types of Pyramid-Shaped Artificial Reefs (피라미드형 패조류용 어초의 수리학적 특성)

  • Sohn, Byung-Kyu;Lee, Jeong-Woo;Yi, Byung-Ho;Yoon, Han-Sam
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.34 no.5
    • /
    • pp.725-734
    • /
    • 2010
  • This study conducted hydraulic testing to assess the stability of two types of pyramid-shaped artificial reefs (ARs) constructed to promote the growth of shellfish and seaweed. Previous theoretical and hydraulic experimental studies have clearly demonstrated Froude similitude. The results of this study revealed that some dimensionless design parameters affected the stability of both types of artificial reefs under various wave and current field conditions (e.g., surf similarity parameters, water particle velocity, wave pressure). In the fixed bed condition, the dimensionless water particle velocity based on the surf similarity parameter was large (about 0.4), and in the moveable bed condition, the relative water depth based on the dimensionless wave pressure was low (about 0.11). In addition, horizontal wave pressure and uplift pressure varied by relative water depth, demonstrating the tendency for wave pressure to decrease linearly with increased relative depth. These findings indicate that the development of more stable design technology forartificial reefs should be based on long-term data and additional study of sliding due to wave action. The findings also highlight the importance of hydraulic experiments in solving problems that have emerged in the design and construction of artificial reefs.