• Title/Summary/Keyword: 안강망

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Seasonal Variation in Species Composition of Fish Collected by a Bag Net in the Geum River Estuary, Korea (개량안강망에 채집된 금강하구 어류 종조성의 계절 변동)

  • HWANG Sun-Wan;HWANG Hak-Bin;NOH Hyung-Soo;LEE Tae-Won
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.38 no.1
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    • pp.39-54
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    • 2005
  • Seasonal variation in species composition of fish in the Geum River estuary was determined using monthly samples collected with a bag net from February to December 2003. Of a total of seventy-three species collected, four groups of fishes were distinguished. Estuarine fishes such as Chelon haematocheilus and Synechogobius hasta were collected almost all the seasons and predominated in abundance during cold months. Coastal fish species such as Sardinella zunasi, Konosirus punctatus, Engraulis japonicus, Johnius grypotus and Thryssa kammalensis were dominated from late spring to autumn. Their adults entered into the estuary in spring and a large number of their juveniles were collected in summer and autumn till moving out to deeper waters for over-wintering. A few freshwater fishes were collected when the freshwater was discharged during the rainy season. Anguilla japonica elvers (diadromous fish) and Coilia nasus (amphidromous fish) were collected in spring during their upstream migration. The principal component analysis revealed that the seasonal variation in species composition of fishes was principally determined by water temperature and/or water temperature related factors.

Offshore stow net modeling and analysis of behavior using numerical methods (수치해석을 이용한 근해안강망 어구 모델링과 거동분석)

  • JANG, Yong-Suk;LEE, Chun-Woo;CHOI, Kyu-Suk
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.57 no.4
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    • pp.283-291
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    • 2021
  • The Korean stow net is a fishing method that utilizes the changing direction of the net entrance with the tidal current. This study attempted to obtain basic data from the recent offshore stow net fisheries to improve the gear by analyzing the dynamic behavior of the nets affected by current speed and direction using computer simulations. A numerical calculation was performed at a current speed of 0.5 knot between 2.5 knot at each 0.5 knot. The time taken for the gear opening was the longest from 0.5 knot at 1,500 seconds and the shortest from 2.5 knot at 450 seconds in the simulations. In all cases, the net width and tension at net deployment gradually decreased as the current speed decreased. However, the net height tended to increase inversely proportional to the current speed. During the net rotation, the net height was maintained at all cases. The net width and tension fluctuated, but the regularity was very low. In this study, the calculated simulation data showed that the opening efficiency decreased proportional to the current speed. The opening efficiency is related to the catching efficiency; therefore, it is necessary to improve the gear to enhance its opening efficiency.

Effects of improvement of fishing operating system on a coastal improved stow net fishing vessel on the work safety and workload of seafarers (연안개량안강망어선의 조업 시스템 개선이 선원들의 작업 안전과 작업부하에 미치는 영향)

  • Min-Son KIM;Ho-Young CHANG;Bo-Kyu HWANG
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.59 no.1
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    • pp.74-84
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    • 2023
  • This paper is the result of a comparative analysis of crew members' workloads using the EMG and OWAS methods according to the fishing process before and after the improvement of the operating system of the experimental vessel, with the aim of improving operational efficiency and safety work of coastal improved stow net fishing vessels. The target crew members were three people with at least five years of experience on board the same fishing vessel as the experimental vessel. After improving the operating system, such as installing a power block crane and two capstans, change the location of the ball-roller, the time required for setting and hauling work decreased (p < .01), and the evaluation results by OWAS showed that the overall workload for setting and hauling net work decreased. The results of muscle activity analysis showed a decrease in lashing anchor work (p < .01) in the case of hauling net and in anchor dropping work in the case of setting net (p < .001). It is judged that the use of ball rollers in net handling has been reduced; consequently, work safety has been improved.

Investigation on bycatch reduction methods of marine mammals for fishing with gill net, trap, trawl, stow net and set net (자망, 통발, 트롤, 안강망, 정치망 어업에 대한 해양포유류 혼획 저감 연구 조사)

  • Kyu-Suk CHOI;Hyun-Su JO;Myounghee KANG
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.59 no.4
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    • pp.279-289
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    • 2023
  • The United States enforces the seafood import regulations so-called the Marine Mammal Protection Act (MMPA), and by 2023, all exports of aquatic products and processed fish products by fisheries which have not obtained an "Comparability Finding" from the National Oceanic and Atmospheric Administration will be completely banned. Therefore, to respond to the US MMPA, it is critical to identify technologies and methods used in worldwide for reducing bycatch of marine mammals. In particular, marine mammals are frequently caught in five fisheries (trawl, gill net, trap, stow net and set net) in Korea, which is facing a great challenge. This study presented bycatch reduction methods by five fisheries, classified the methods by country, and suggested appropriate reduction methods which can be applied in Korea.

A Study on the Design of the Stern Stow Net (선미식 안강망 어구의 설계에 관한 연구)

  • 김진건
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.4
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    • pp.343-352
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    • 1999
  • Because stow net being used in now is doing throwing net and hauling net through a ship's side, the work is very complicated and the fishing boat needs many seamen and it could cause a loss of lives and ship in stormy weather. We are now using small mesh size 36~500mm and it even catches young fish, so we call it the fishing gear of resource reduction type.Therefore we must make manpower reduction in automatic operation, safe operation of throwing net and hauling net in the stern and the stern-typed stow net of resource management using large mesh. And we performed three-typed model tests to examine the fishing gear. The obtained results are as follows;1. The fishing gear being used in the ship's side type stow net has inappropriate standard and arrangement of the net, resistance increase of the fishing gear and frequent breakdown of the net.2. To supplement the fault of A-typed stow net, we schemed fishing gear developed as both B-type(12-seamed net) and C-types(8-seamed net) of the stern-typed stow net. 3. In model tests, C-typed model net(mesh size 40~1,600mm) was proved good fishing gear because the resistance in accordance with the flowing speed was comparatively small and it's mouth area was broad. 4. A-typed stow net had the spreading device attached to side panel of the net, but the stern-typed stow net had the spreading device consisted of 4 lines far behind about 6m from side panel of the net mouth. In the flowing speed 2knot, the spreading condition of fishing gear was proved batter than the former.

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A study on the cost state of the stow net Fishery (근해안강망어업경영의 원가실태에 관한 연구)

  • 박정호
    • The Journal of Fisheries Business Administration
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    • v.9 no.2
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    • pp.59-89
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    • 1978
  • The analyzed results of the actual state of stow net fishery based on the cost expended are as follows. According to the calculation of interests, the total cost of this fishery comes to ₩38,010,653 and in this account, the production cost comes to ₩35,477,198(93.3%), the material cost, 14,567,239(38.3%), the labour cost, 12,740,274(33.5%), the expenses, ₩8,169,685(21.5%), the commision and administration expenses, 2,533,455(6.7%). The expenses for this fishery are paid out as production costs, and the expenses for sale and administration expenses are the lowest of them, and the 93% of expenses are paid out as production costs. The ratio of cost element to 100% is as follow. The wages, 28.4%, fuel, 15.2%, repair, 11.6%, deprecation, 9.5%, fishing gear, 8.7%, ice, 6.1%, container(box for fish), 5.2% administration expenses, 5.2%, food, 3.5%, ship grar, 3.2%, public welfare, 1.7%, commision for sale, 1.5%, insurance for crew, 0.2%, taxes, 0.2%. This fishery is managed with the larger fishing boat than it was and so, it demands better crews with higher wages. In the former fishery, the search for fishing ground is very difficult with long navigation and great fuel consumption. when the weak fishing gears are used, the expenses for their repair and for their gears are greatly paid out. The unit costs of catches to each box come to ₩2.807(₩187 each kg). As the ratio of cost of sales comes to 86.7%and the ratio of interests comes to ₩5,850,812(13.3%), and so the net profit comes to 13.3% of total profits. According to above the ratio of cost of sales is shown as a universal validity, Asthe total expenses comes to 86.7% to the money on sales in the break-even point, the break-even point comes to ₩26,209,168 Accordingly for the profit control the account of production should be raised, and by the saving method of expenditure the break-even point should be brought down for the development of total profits.

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Distribution and Spawning of the Yellow Goosefish , Lophius litulon (황아귀 Lophius litulon 의 분포와 산란)

  • 차병열
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.33 no.2
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    • pp.97-108
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    • 1997
  • Variation of the catches and fishing grounds, and spawning ecology of Lophius litulon caught by large staw net were investigated from following as ; L. litulon caught through the year, and the peak in catches showed on January in winter, and the lowest catches showed on August in summer. The fishing grounds of L. litulon were located in the Yellow Sea and the East China Sea. And the main fishing ground was formed in the adjacent waters of Ilhyang-cho, where catches and CPUE were more than 50 M/T, 5 kg/haul, respectively, and the range of coefficient of variation(C.V) was 0.6~0.7. The spawning season of L. litulon was on March and April, when spawning area was formed in waters between Ilhyang-Cho and Cheju-Do. The fishing grounds distribution of L. litulon was obviously different with seasonal variation. Namely, in winter, the fishing grounds were mainly formed in the western waters of Cheju-Do, and on March and April( in spawning season), the fishing grounds were densely formed in the adjacent waters of Ilhyang-Cho, and after May, the fishing grounds were widely dispersed towards in the Yellow Sea and the East China Sea with temperature upgrade.

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Catches comparison according to the codend mesh size of stow net on anchor in the West Sea of Korea (서해안 안강망의 끝자루 망목크기에 따른 어획 비교)

  • Cho, Sam-Kwang;Park, Chang-Doo;Kim, Hyun-Young;Kim, In-Ok;Cha, Bong-Jin
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.1
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    • pp.1-9
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    • 2010
  • Experimental fishing was carried out to compare fishing status according to the codend mesh size (raschel, 15mm, 25mm, 35mm, 45mm) of stow net on anchor in the coastal waters of Seocheon after manufacturing five kinds of fishing gears and commercial fishing boat (7.93 tons) was used for it. Total catches of raschel, 15mm, 25mm, 35mm, 45mm codend were 816,949g, 203,994g, 1,405g, 51,576g, 194g in September and 40,545g, 66,974g, 14,692g, 12,647g, 12,655g in October. Dominance species were anchovy (Engraulis japonicus) in raschel codend, largehead hairtail (Trichiurus lepturus) in 15mm and 35mm in September, and the amount of catches was very small in 25mm and 45mm codend due to the fishing gear damage. In October, dominance species were anchovy and beka squid (Loligo beka) in raschel, 15mm, 25mm codend, and cuttlefish (Sepia esculenta) and beka squid were mainly caught in 35mm and 45mm codend. In addition, total length of anchovy and cardinal fish (Apogon lineatus) were increased according to the increase of codend mesh size but there was no difference in the mantle length of cuttlefish and loligo beka.

Age and Growth of Brown Croaker Miichthys miiuy in the South-western Water of Korea (한국 서남해 민어(Miichthys miiuy)의 연령과 성장)

  • Lee, Seung Hwan;Chung, Sang Deok;Yoo, Joon-Taek;Kim, Yeong Hye
    • Korean Journal of Ichthyology
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    • v.29 no.1
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    • pp.69-74
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    • 2017
  • Age and growth of Brown croaker Miichthys miiuy were estimated using right sagittal otoliths of 327 fish specimens from August 2015 to July 2016 in Korea. Annual rings in otoliths were formed from March to June once a year. The oldest specimens were 11 yr in female and 9 yr in male. Brown croaker began spawning in September and showed a peak in October. Total length and body weight relationships showed no significant difference between females and males (P>0.05), and can be expressed as $BW=1.15{\times}10^{-5}{\times}TL^{2928}$ ($R^2=0.98$). Estimated von Bertalanffy growth curve was $L_t=182.4(1-e^{-0.067(t+1.754)})$ ($R^2=0.96$).

A Simple Guidance Method for the KM , KG , KB , and GM of Small Fishing Vessels (소형 어선의 복원성 요소 KM , KG, KB, GM의 간이유도법)

  • 박중희
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.20 no.2
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    • pp.91-95
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    • 1984
  • This paper describes to analyze regression relation between the ratio mean draft to freeboard and KM/dm, KB/dm and GM/B, respectively with the 43 Korean fishing vessels (7 Danish seiners; 1l Stowers; 14 Poler and liners; 6 Trawlers; 5 Purse seiners) and the 1 Cargo boat in order to obtain the stability factors of the Korean fishing vessels conveniently. The obtained results are as follows; 1. The stability factors by fishing vessels have a tendency to the larger f/dm, the larger KM/dm and KG/dm, and KB/dm and GM/B are constant. 2. It is found out that M and G differ from the kinds of the fishing vessels because KM/dm is the largest in poler and liners and KG/dm in Danish seiner, respectively. 3. It is confirmed that the stability factors of the fishing vessels which the inclining experiment carry out the wholly in the light and the full loaded condition are the same as the inclining experiment uniformly.

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