• 제목/요약/키워드: 안강망

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

  • 황선완;황학빈;노형수;이태원
    • 한국수산과학회지
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    • 제38권1호
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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.

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

  • 장용석;이춘우;최규석
    • 수산해양기술연구
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    • 제57권4호
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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.

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

  • 김민선;장호영;황보규
    • 수산해양기술연구
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    • 제59권1호
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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.

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

  • 최규석;조현수;강명희
    • 수산해양기술연구
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    • 제59권4호
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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.

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

  • 김진건
    • 수산해양기술연구
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    • 제35권4호
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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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근해안강망어업경영의 원가실태에 관한 연구 (A study on the cost state of the stow net Fishery)

  • 박정호
    • 수산경영론집
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    • 제9권2호
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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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황아귀 Lophius litulon 의 분포와 산란 (Distribution and Spawning of the Yellow Goosefish , Lophius litulon)

  • 차병열
    • 수산해양기술연구
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    • 제33권2호
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    • pp.97-108
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    • 1997
  • 황해와 동중국해역에서 근해안강망에 의해 어획되는 황아귀의 어획량 변동과 어장 분포, 그리고 산란 생태를 구명한 결과는 다음과 같다. 황아귀는 연중 어획되며, 이중 많이 어획되는 시기는 겨울철, 가장 적게 어획되는 시기는 여름철인 것으로 나타났다. 황아귀의 어장은 황해와 동중국해에 널리 분포하고 있으며, 중심어장은 일향초 주변 해역으로 어획량이 50 M/T 이상, CPUE가 5kg/haul 이상, C.V는 0.6~0.7의 범위로 낮게 나타났다. 황아귀의 산란시기는 3월과 4월경이며, 이때의 산란장은 일향초와 제주도 사이해역에서 형성되는 것으로 추정되었다. 황아귀의 어장은 월별에 따라 이동하는 현상을 나타내었는데, 즉, 겨울에는 황해저층냉수와 대마난류수의 남하로 어장은 제주도 서방해역에 주로 분포한다. 또 산란시기인 3월과 4월경이 되면, 일향초 부근 해역으로 어장이 밀집하지만, 산란이 끝난 5월이후가 되면 수온의 상승과 더불어 어장은 황해와 동중국해역으로 널리 분산되는 것으로 나타났다.

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

  • 조삼광;박창두;김현영;김인옥;차봉진
    • 수산해양기술연구
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    • 제46권1호
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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.

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

  • 이승환;정상덕;유준택;김영혜
    • 한국어류학회지
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    • 제29권1호
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    • pp.69-74
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    • 2017
  • 본 연구는 우리나라 주요 수산자원 중 하나인 민어의 이석을 이용하여 민어의 연령과 성장을 추정하였다. 연구에 사용된 민어의 이석은 2015년 8월부터 2016년 7월까지 서해 남부 연안에서 안강망으로 어획되어 양육된 것으로 총 339개체 중, 연령사정에 이용된 개체수는 327미였다. 연령은 민어는 불투명대에서 투명대로 이행하는 지점을 윤문으로 간주하였으며, 윤문형성시기는 3~6월(주형성시기 6월), 산란기는 9~10월 (주산란기 9월)로 추정되어 초륜이 형성되기까지의 기간은 0.75년으로 나타났다. 최고 연령은 암컷 11세, 수컷 9세로 추정되었으며, 윤문이 형성될 시기의 평균 전장을 바탕으로 비선형 회귀방법으로 추정한 Von Bertalanffy 성장식은 $L_t=182.4(1-e^{-0.067(t+1.754)})$($R^2=0.96$)이었다.

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

  • 박중희
    • 수산해양기술연구
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    • 제20권2호
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    • pp.91-95
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    • 1984
  • 어선에서 선도나 경사시험자료가 없는 선박에서도 임의의 재하상태때 복원성요소 값을 얻을 수 있는 근사식을 구하기 위해 1980년에서 1983년 사이에 우리나라에서 건설된 어선 43척의 만재상태와 공하상태의 경사시험자료를 이용하여 각 선박의 평균흘수(dm)와 건현(f)의 비 값에 대한 KM/dm, KG/dm, KB/dm, GM/B의 값을 회로분석한 결과는 다음과 같다. 1. 어선별 복원성요소값은 어느 선형에서나 f/dm 값이 커질수록 KM/dm 및 KG/dm 값은 커지는 경향을 나타내었으며, KB/dm 및 GM/B의 값은 일정하게 변하였다. 2. KM/dm, KG/dm는 안강망어선, 기선저인망어선이 각각 가장 큰 경향을 나타내어 어업선의 종류에 따라 M과 G의 값이 다르게 됨을 알 수 있었다. 3. 업종별어선의 복원성요소값은 공하상태와 만재상태의 경사시험한 자료만으로서 정선적인 경사시험한 것과 같은 경향을 나타내고 있음을 확인할 수 있었다

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