• Title/Summary/Keyword: 선망

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A Comparative Study of Sea Trials and Production Processes for Propulsion Type Working Boats with a Tuna Purse Seiner (다랑어 선망어선 탑재용 보조 작업선의 추진기 형태 변화에 대한 제작과정 및 해상시운전 비교 연구)

  • Ha, Seoung-Mu;Jang, Ho-Yun;Seo, Hyoung-Seock;Seo, Kwan-Cheol
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.5
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    • pp.595-602
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    • 2017

  • In Korea, much research and development have occurred to enhance the technological competitiveness of tuna purse seining fisheries. Due to these efforts, fishing efficiency has been improved with the development of radar, sonar and global positioning systems for fish detection and revisions to the hull forms of tuna purse seiners. However, for skiff boats, net boats and speed boats, which are auxiliary working boats mounted on tuna purse seiners, technology has lagged behind relative to the modernization of the main vessel. In this study, the hull of an existing propeller-based net boat with steel wire net to protect tuna was changed to the hull of a water jet propulsion vehicle to reduce resistance and improve maneuverability. As a result, a prototype of a water jet propulsion option was produced according to the aluminum structure strength standards specified by the Ministry of Oceans and Fisheries, and safety was confirmed by performing a drop test. Moreover, through a sea trial test, an existing net boat was shown to have a speed of 12.0knots and a towing force of 2,545 kgf at 2,500 RPM. The prototype had a speed of 26.7 knots and a towing force of 2,011 kgf at 3,200 RPM, which satisfied the towing capacity standards of auxiliary working boats mounted on tuna purse seiners.

  • https://doi.org/10.7837/kosomes.2017.23.5.595 인용 PDF KSCI

On the Tuna Schools Associated with the Drift Objects or Animals in the Western Equatorial Pacific Waters (태평양 서부 적도해역에서 부류물체나 동물과 함께 발견된 다랑어 어군에 관하여)

  • PARK Sing-Won
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.17 no.1
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    • pp.47-54
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    • 1984

  • From the four tuna purse seiners operating in the western equatorial Pacific waters 370 tuna schools were sampled on attribute of the school, fishing operation of purse seine sit and catch. The data were tabulated and subjected to the statistical tests of independency on the associated object and availability of the school, and catch per set of purse seine fishery as well. The resultant inferences are as follows. 1. Most frequent attributes of the tuna schools found on the surface are associated with sea birds, bait fishes and the flotsams. 2. In fishing operations of purse seine sets on the flotsam-associated schools, the settings were more frequently performed at dawn than in day-time. In fishing operations on the sea-birds-associated schools, the siftings were more frequent in day-time than at dawn. 3. From the flotsam-associated schools the successful sets were significantly more frequent. 4. In the fishing operations of purse seine sets, some of the flotsam-associated schools were subjected to the supplementary sets in success to the initial sets until the schools were consummated. 5. The fish-attracting effect of the flotsam is correlated with structure of the flotsam, but not with length of the flotsam. The flotsams, which tend to attract large tuna schools are the complicated-structure flotsams, i, e. driftwoods with roots or branches or with both of them, otherwise a bunch of uprooted bamboo shrubs, while a log without roots and branches tend to be an attractant inferior to the flotsam of complicated structure.

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Development of Tuna Purse Seine Fishery in Korea and the Countries Concerned (한국(韓國) 및 관련각국((關聯各國)의 다랑어 선망어업(旋網漁業) 발달과정(發達過程))

  • Hyun, Jong-Su;Lee, Byoung-Gee;Kim, Hyoung-Seok;Yae, Young-Hee
    • Journal of Fisheries and Marine Sciences Education
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    • v.4 no.1
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    • pp.30-46
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    • 1992

  • Korea's first exploratory tuna fishing was done with a used longliner in 1957. Then the commercial fishing has been made steady headway since the 1960's and grown up to one of major tuna fishing countries in 1970's. The tuna fishing aimed primarily at acquiring foreign currency, then tuna was exported directly from the overseas fishing base. Tuna, however, has been gradually favored by Koreans as high-proteined foods according to the growth of GNP since the 1970's. In 1980, the canned tuna began to be produced and sold at home. And so the demand of raw tuna for cannaries has steeply increased not only for home but also for abroad, and stimulated the development of tuna purse seine fishery. The author carried out a study on the development of tuna purse seine fishery in Korea and countries concerned-the United States and Japan-because it is recognized to be significant for the further development of this fishery. Just as purse seining was originated in the United States, so tuna purse seining was also pioneered by Californian fishermen in the west coastal waters of the United States (Eastern Pacific Ocean). They started to produce the canned tuna in the early 1900's, and the demand for raw tuna began to be increased rapidly. In those days, tuna was mostly caught by pole-and-line, but the catch amount was far away from the demand. To satisfy this demand, they began to try out fishing tuna by the use of purse seine which had been born in the eastern waters in the 1820's and applied to catch white fishes in the western waters of the United States in those days. Even though their trial was technically successful through severe trial and error, a new problem was raised on the management of tuna resource and the preservation of porpoise which was occassionally caught with tuna. Then the Inter-American Tropical Tuna Commission (IATTC) was established by countries neighboring to the United States in 1950 and they set up the Commission's Yellowfin Regulatory Area (CYRA) and regulated the annual quota for yellowfin. Then, American owners tried to send their seiners to the Western African waters to expand the fishing ground in 1967 and to the Centeral-Western Pacfic in 1974, and the fishing ground was widely expanded. The number of the United States' purse seiners amounted to about 150 in 1980, but the enthusiasm was gradually cooled thereafter and the number of seiner was decreased to 67 in 1986. The landing of tuna by purse seiners in the United States after 1980 maintains 200 thousands M/T or so with a little increase despite the decreasing of domestic seiners. This shows that the landing by foreign seiners are increasing, compared with the landing by domestic seiners are decreasing. In Japan, even though purse seining was introduced in 1880, they had fished tuna by longline and pole-and -line until the tuna purse seining was introduced from the United States again. In the 1960's, Japanese tuna seiners made the exploratory fishing in the South-western Pacific and West African waters with a limited success. In 1971, the government-funded research center "JARMRAC" conducted the exploratory fishing which extended to the Central American waters, the Asia-Pacific Region and the South-western Pacific. It had also much difficulties, till they improved the fishing gear adaptable to the new fishing condition in the South-western Pacific. Japanese government has begun to licence 32 single seiners and 7 group seiners since 1980 and their standard has lasted up to now. The catch in the Pacific Islands Region amounted to 160 thousands M/T in 1986. Korea's tuna purse seine fishery was originated in 1971 by Jedong Industrial Co., Ltd. with three used tuna purse seiners purchased from the United States, and they began to fish in the Eastern Pacific, but failed owing to the superannuation of vessel and the infancy of fishing technique. The second challenge was done by Dongwon Industrial Co., Ltd. in 1979, with one used seiner purchased from the United States, and started to fish in the Eastern Pacific. Even though the first trial was almost unsuccessful but they could obtain the noticeable success by removing the vessel to the South-western Pacific in 1980. This success stimulated the Korean entherprisers to take part in this fishery, and the number of Korean tuna purse seiners has been increased rapidly in accordance with the increased demand for raw tuna. The number of vessels actually at work amounted to 36 in 1990 and they operate in the South-western Pacific. The annual catch of tuna by purse seiners amounted to 170 thousands M/T in 1990 and ranked to one of the major tuna purse seining countries in the world.

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Studies on the Improvement of the Fishing Efficiency of Purse Seine in the Sea Area of Cheju Island -The Changes of Seine Volume and Tension in the Purseline During Pursing- (제주도 주변해역 선망의 어획성능 향상에 관한 연구 -짐줄 체결 중 선망의 용적과 짐줄의 장력 변화 -)

  • 김석종
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.2
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    • pp.93-101
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    • 1999

  • A simple experimental method was used in an attempt to realize the elevation of the fishing ability of purse seine in the sea area of Cheju Island, the changes of seine volume and tension in the purseline during pursing. Experiments carried out on the six types simplified reduced model seines which were made of knotless nettings. The nettings were woven in different leg length 4.3, 5.0, 5.5, 6.0, 6.6 and 7.7mm of polyester 28 tex two threads two-ply twine, and each of the seines were named I, II, III, IV, V and Ⅵ seine. Dimension of seine models were 450cm for corkline and 85cmfor seine depth, each seines rigged up 160g of float for a floatline and 50g (underwater weight) of lead for a leadline. These model purse seines were made of the scale of 1/200 of its full scale, a 120 ton in the near sea of Cheju Island. Designing and testing for the model purse seines were based on the Tauti's law. Experiments were measured in the observation channel of a flume tank at the static conditions set up shooting and pursing equipments. Motion of purse seine during purse line was recorded by the two sets video camera for VTR which were placed in top and front of the model seine. The reading coordinate of seine volume carried out by the video digitization system, disk data for the purseline tension. An analysis were performed on the changes seine volume and tension in the purseline during pursing. The results obtained were as follows: 1. The seine volume during pursing was largest for Ⅵ seine with smallest d/l followed by V, IV, III, II and I seines, and tension in the purseline was small. 2. Seine volume during pursing can be expressed by the following equation; CVt=l-EXP[｛2.79 (d/l）＋0.35｝t-33.37 (d/l) ＋ 0.57] Where CVt is volume ratio, d is twine diameter, l is leg length and t is pursing time (sec). 3. Tension in the purse line during pursing can be expressed by the following equation; T= 1- EXP ｛0.57t ＋ 13.36 (d/l)+2.97｝ Where T is tension (kg) in the purseline during pursing.

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