• Title/Summary/Keyword: Fishing operation

Search Result 288, Processing Time 0.024 seconds

Distribution of the Trawl Catch off the Shara Coast of Africa (아프리카 사하라 연안 트로올 어장의 어획량분포에 관하여)

  • Kim, Jin-Geon;Son, Tae-Jun
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.19 no.1
    • /
    • pp.1-11
    • /
    • 1983
  • Data on the trawl operation was compiled from the Korea stern trawlers operated in the sea off the Sahara coast of Africa from May 1975 to April 1976. The distribution of some important demersal fishes were investigated by calculating the catch per haul in every fishing ground sections divided by every fishing ground sections divided by every 30' of latitude and longitude. The results obtained are as follows; 1. The mean catch per haul calculated as: squid 14.9kg, large cuttlefish 29.9kg, small cuttlefish 37.8kg, octopus 44.1kg, sole 8.0kg, seabream 9.3kg and miscellaneous fishes 63.1kg. Where cuttlefish is divided into two sizes, large or small by if it weighs over 300kg or not. 2. Squid were caught mostly from August to November in the northern part of 24$^{\circ}$30'N and southern part of 23$^{\circ}$30'N. 3. Large cuttlefish were caught mostly from December to May of the next year, in the coast from 23$^{\circ}$00'N to 25$^{\circ}$00'N, where as small cuttlefish were caught mostly from April to June and from November to January of next year, in the coast from 23$^{\circ}$30'N to 25$^{\circ}$00'N. 4. Octopus were caught mostly from September to January of the next year and from March to April. in the coast from 23$^{\circ}$00'N to 25$^{\circ}$00'N rather in the offshore than in the near coast. 5. Miscellaneous fishes including seabream were caught from May to November, sole from June to November and the others from May to October.

  • PDF

Three-dimensional Simulation of Wave Reflection and Pressure Acting on Circular Perforated Caisson Breakwater by OLAFOAM (OLAFOAM에 기초한 원형유공케이슨 방파제의 반사율 및 작용파압에 관한 3차원시뮬레이션)

  • Lee, Kwang-Ho;Bae, Ju-Hyun;Kim, Sang-Gi;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.29 no.6
    • /
    • pp.286-304
    • /
    • 2017
  • In this study, we proposed a new-type of circular perforated caisson breakwater consisting of a bundle of latticed blocks that can be applied to a small port such as a fishing port, and numerically investigated the hydraulic characteristics of the breakwater. The numerical method used in this study is OLAFOAM which newly added wave generation module, porous media analysis module and reflected wave control module based on OpenFOAM that is open source CFD software published under the GPL license. To investigate the applicability of OLAFOAM, the variations of wave pressure acting on the three-dimensional slit caisson were compared to the previous experimental results under the regular wave conditions, and then the performance for irregular waves was examined from the reproducibility of the target irregular waves and frequency spectrum analysis. As a result, a series of numerical simulations for the new-type of circular perforated caisson breakwaters, which is similar to slit caisson breakwater, was carried out under the irregular wave actions. The hydraulic characteristics of the breakwater such as wave overtopping, reflection, and wave pressure distribution were carefully investigated respect to the significant wave height and period, the wave chamber width, and the interconnectivity between them. The numerical results revealed that the wave pressure acting on the new-type of circular perforated caisson breakwaters was considerably smaller than the result of the impermeable vertical wall computed by the Goda equation. Also, the reflection of the new-type caisson breakwater was similar to the variation range of the reflection coefficient of the existing slit caisson breakwater.

Mechanization of Fishing Operation on the Sea Eel Pots - 3 . Automatic Loop Catcher and Recoiling System of the Main Line - (장어 통발어업의 자동기계화에 관한 연구 - 3 . 모릿줄과 고달이채기의 자동화 -)

  • 하정식
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.26 no.2
    • /
    • pp.118-124
    • /
    • 1990
  • The rope winder in addition to the line hauler was used for recoiling of the main line to the rope pond at the stern, however, catching the loops, evenly revoiling and arrangements of the loops were done manually by two men. The automatic loop catcher under the rope winder was consisted with the rotary lever, semicircle guide plates, transfer belt and swing rope receiver for arrangements of the loops and evenly recoiling. The obtained results are as follows: 1. The minor diameter of a loop and the diameter of the coiling pile in a lead core PP rope(ø 10mm) are about 14cm and 60cm while the rope is piled on the bottom. 2. Distribution ratio of the loops within upper or lower 10cm from the transfer belt is 93% with a lead sinker and 98% without sinker using by the smaller loop catcher. 3. The relationship between revolutions of the rotary lever N sub(1) (rpm) and the hauling pulley N sub(p) (rpm) by gear ratio 3:1 in the smaller loop catcher is as follows: N sub(p) =2.86 N sub(1) +23.74 and optimum ratio of horizontal speed of the loops by the rotary lever to hauling speed is about 70%. 4. The rope receiver is swung front and rear for the evenly recoiling and its period can be controlled by gear ratio or hydraulic circuit in accordance with the interval of the loops.

  • PDF

Study on the Anchovy Boat Seine-IV An Experiment to Mechanize the Hauling Operation of Bag Net (기선권현 강의 연구 -IV)

  • 이병기
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.15 no.2
    • /
    • pp.95-100
    • /
    • 1979
  • In fishing with the anchovy boat seine, it is required to haul up the bag net without injuring anchovy body. Not to injure anchovy body, the bag net is operated with 30 to 34 crews in the traditional method. With a view point of decreasing crews, the authors tried to operate the bag net with side drum winch and derrick boom. Side drum winch was installed beside the engine casing and it was operated by the main engine through the belt, pulley and bevel gear. The derrick boom, 7 meters long, was installed above the working deck which is located in the stern of the common boat seiner. Three single blocks are attached to the boom, each 2 meters apart from the top. A hook was attached to the free end of the block line for hooking up the bolch line which attached inside the bag net especially prepared for the purpose. The hauling end of the block line was induced to the side drum winch for hauling up the bag net. By using this mechanism, the bag net was hauled up with peeling the bag net just like in the traditional method. So the following results are found. (1) No injury of anchovy body was found in the process of hauling up. (2) The bag net can be operated by mere 14 crews. (3) Duration, spent in hauling up the bag net, was almost the same when the catch are a little amount, and less duration was needed by the experimented method than the traditional one when the catch are a large amount. the bag net. By using this mechanism, the bag net was hauled up with peeling the bag net just like in the traditional method. So the following results are found. (1) No injury of anchovy body was found in the process of hauling up. (2) The bag net can be operated by mere 14 crews. (3) Duration, spent in hauling up the bag net, was almost the same when the catch are a little amount, and less duration was needed by the experimented method than the traditional one when the catch are a large amount.

  • PDF

A Study on the History of School and Community Libraries Movement in Korea (학교마을도서관 운동사에 관한 연구)

  • Byeon, Hyeon Ju;Cho, Miah
    • Journal of the Korean BIBLIA Society for library and Information Science
    • /
    • v.27 no.2
    • /
    • pp.151-170
    • /
    • 2016
  • The purpose of this study is to analyze performance factors of the school and community libraries in its beginning, growth, development, and expansion to identify the assignment of the movement at the present stage. In this study, we performed interviews with those concerned with the school community and library movement and collected various relevant literature. The school and community libraries movement can be divided into five stages including beginning, growth, development, expansion, and turning point. Therefore performance and significance of school and community libraries shown in the history of the movement may be summarized as follows. First, school and community libraries were established mainly in areas isolated from cultural benefits, contributing to resolving problems such as a lack of public libraries and concentration of small libraries in certain areas. Second, the movement promoted the operation of school libraries by providing books for small-sized elementary schools in farming & fishing villages and mountain villages, libraries that were insufficient in books. Third, the movement utilized the minimal personnel, books, and spaces of school libraries to provide library services to community residents, securing permanence of library services, if nothing else. Fourth, school and community libraries played the role of local community-based libraries, intensifying the community spirit of residents and vitalizing communities.

Acoustic Target Strength of the Pelagic Fish in the Southern Waters of Korea I. In situ Measurement of Target Strength of Anchovy (Engraulis japonica) (한국 남해안 부어류의 음향반사강도에 관한 연구 I. 멸치 (Engraulis japonica)의 in situ 반사강도 측정)

  • YOON Gab Dong;KIM Zang Geun;CHOI Young Min
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.29 no.1
    • /
    • pp.107-114
    • /
    • 1996
  • The in situ target strength for the anchovy (Engraulis japonica) were measured by the split beam echo sounder system at 38 kHz. This study allowed us to detect the single echos from anchovy shoals which were dispersed during trawling operation in day time. The results of our study were as fellows: We found that the anchouy occupied about $95\%$ of the total catch from the detected shoals from which target strength data were collected. Length distribution of anchovy showed a mode and ranged from 13.6 to 15.4cm with a mean of 14.4cm and a standard deviation of 0.45cm, and weight distribution showed a mode and ranged from 16 to 28 g witha mean of 21.9 g and a standard deviation of 2.7 g. The target strength distribution of anchovy ranged from -40.7 dB to -69.2 dB in the water layer of ,$10\~30\;m$ -42.19 to -67.7 dB in the $30\~50\;m$ and -42.2 to -67.7 dB in $10\~50\;m$, showing 2 modes in each layer, respectively. Overall mean target strengths were -49.7 dB/fish and -33.1 dB/kg, averaged by area backscattering cross section $(\sigma)$, and the confidence interval for target strength was less than 1 dB. With the mean total length and the mean target strength, we drived the target strength-length relationship as $TS(\sigma)=20\;Log\;L-72.9$.

  • PDF

Improving of the Fishing Gear and Development of the Automatic Operation System in the Anchovy Boat Seine-III -Underwater Geometry of the Prototype Net- (기선권현망어업의 어구 개량과 자동화 조업시스템 개발-III - 실물어구의 수중형상 -)

  • 장충식;김용해;안영수
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.37 no.4
    • /
    • pp.267-274
    • /
    • 2001
  • A prototype experiment on the anchovy boat seine was carried out in the southern sea of korea to analyze the vertical opening and the underwater geometry. The vertical opening and the underwater geometry of the prototype net were determined by distance of Minilog position with the combinations of the distance between paired boats and the towing speed. The results osbtained can be summarized as follows; 1. Vertical opening of the protype net was gradually lowered according to the increase of the distance between paired beats and the towing speed. 2. Vertical opening of Wing net, Inside wing net, Square, Fore bag net, Flapper and After bag net of the prototype net according to the distance between paired boats were varied in the range of 8.4~9.0, 15.7~17.4, 12.9~17.9, 13.6~19.0, 8.3~8.4, 11.1~14.7m respectively, varied in the range of 12~16, 22~24, 27~38, 59~83, 92~93, 41~54% of the normal opening respectively. 3. Vertical opening of Wing net, In side wing net, Square, Fore bag net, Flapper and After bag net of the prototype net according to the towing speed were varied in the range of 7.7~10.5, 19.6~21.6, 12.2~16.9, 15.4~17.1, 8.0~8.2, 13.7~14.7m respectively, varied in the range of 14~19, 27~30, 32~36, 67~74, 89~91, 51~54% of the normal opening respectively. 4. Prototype net was appeared apparent the pocket shape, because Wing net and Inside wing net was opened 20% of the normal opening. 5. Working depth of the prototype net was gradually shallow according to the increase of the distance between paired boats and the towing speed.

  • PDF

A Study on Supplement of Harbour and Fishery Design Criteria through the Statistical Characteristics Analysis of Cruise Ship's Specification (크루즈선 주요 제원분석을 통한 항만 및 어항설계기준 개선 연구)

  • Cho, Ik-Soon;Cho, Jang-Won
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.23 no.6
    • /
    • pp.652-660
    • /
    • 2017
  • Recently, the number of tourists using cruise ships in Korea is increasing. and an big cruise ship with an gross tonnage of 160,000 tons or more has entered the domestic ports. Therefore, the government has been making a lot of efforts to confirm the cruise infrastructure for revitalization of the domestic cruise industry. However, there are no standards for cruise ship specifications and water facilities in the domestic port and fishery design standards. Currently, construction of dedicated cruise facilities is under way in major domestic ports. However, due to lack of specifications and domestic standards for cruise ships, it is difficult to design and license special facilities. Therefore, in this study, PIANC rule and domestic harbor and designing standard of fishing port were compared and analyzed in order to present the standard specification of cruise ships. And analyzed the representative linearity of cruises currently being operated. As a result of the ship characteristics analysis, There was a difference in coastal passenger ship in specifications and ship maneuverability. Therefore, in order to design facilities dedicated to cruising, the specifications of the target ship must be included in the domestic design standard. In addition, in order to calculate the scope of the target ship, I applied the coverage rate of 75% to the average specification value of the cruise ship and presented the standards of the cruise ship and the standard of the water area facilities.

A Study on the Improvement for Port Placement of Response Vessel (방제선 배치 항만의 개선 방안)

  • Jang, Duck-Jong;Kim, Dae-Jin;Kim, Woo-Young
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.23 no.7
    • /
    • pp.810-819
    • /
    • 2017
  • The purpose of this study is to evaluate port use and the distribution of risk factors in 15 major ports in Korea, delineating the risk of each port after classifying the ports into four risk groups based on estimated risks. The placement of response vessels is then analyzed accordingly. Based on the results, danger was estimated to be especially high in ports where large-scale petrochemical facilities are located, such as Yeosu Gwangyang ports (1.85), Ulsan port (1.33) and Daesan port (1.25). The ports showing the next highest degree of danger were Pusan (0.95) and Incheon (0.83), which have significant vessel traffic, followed by Mokpo (0.71) and Jeju (0.49), which expanded their port facilities recently and saw an increase in large vessel traffic. Next is Masan (0.44), for which many fishing permits in the vicinity. When the relative ratios of each port were graded based on the Yeosu Gwangyang Ports, which showed the highest risk values, and risk groups were classified into four levels, the highest risk groups were Yeosu Gwangyang, Ulsan, Daesan and Pusan, with Incheon, Mokpo, Jeju, and Masan following. Pyeongtaek Dangjin, Pohang, Gunsan, and Donghae Mukho were in the mid-range danger group, and the low risk groups were Samcheonpo, Okgye, and Changsungpo. Among these, all response vessel placement ports specified by current law were above the mid-range risk groups. However, we can see that ports newly included in mid-range risk group, such as Mokpo, Jeju, and Donghae Mukho, were excluded from the pollution response vessel placement system. Therefore, to prepare for marine pollution accidents these three ports should be designated as additional response vessel placement ports.

Standardization Method for Vessel Collision Warning Service Using WAVE Communication Technology (WAVE 선박충돌경보 서비스를 위한 표준화 방안 개발에 관한 연구)

  • Kang, Won-Sik;Kim, Young-Du;Choi, Choong-Jung;Park, Young-Soo
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.25 no.5
    • /
    • pp.542-549
    • /
    • 2019
  • Maritime accidents, such as the collision of a fishing boat in Incheon's Yeongheung Island, result in several casualties and property damage, even if they occur just once. To prevent such accidents, the Incheon Metropolitan Government is implementing safety management policies; further, they will provide ship collision warning services to prevent collisions on WAVE (Wireless Access in Vehicular Environment) communication-based ship safety operation pilot projects. However, to realize these objectives, a service standardization method is required that defines specific service types, configurations, and systems, which should be prepared based on user requirement analyses. In this study, a standardization method of WAVE communication-based collision warning service was developed by analyzing the requirements of the vessel operators subject to the services and related authorities. This will help improve the quality of service, ensuring professionalism and reliability through continuous improvement and efforts for standardization, as well as data derived from demonstration projects. Therefore, it is expected to help prevent maritime accidents to a considerable extent.