• Title/Summary/Keyword: stow net

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General Situations and Reform Measure of Stow-Net Fishing System (근해 안강망 어선 어로 시스템의 현황과 개선점)

  • 문덕홍
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.34 no.3
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    • pp.352-357
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    • 1998
  • 서 언 저자들은 1995년 12월부터 2개년간에 걸쳐 농림수산부가 지원하는 농수산 첨단 연구 과제로서 “안강망 어로 시스템 자동화에 관한 연구 개발을 수행하였다. 이 해설에서는 상기 연구의 초기 단계에 저자들의 조사한 안강망 어선 어로 시스템의 현황과 개선점에 대하여 기술함으로써 향후 안강망어업 관련 연구의 기초자료를 제공하고자 한다.

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A Study on the Hull-dimension of 89 ton class Stow-net Vessel with Stern-fishing (89톤급 선미식 안강망어선의 선형치수에 관한 연구)

  • Park, Je-Ung;Lee, Hyeon-Sang
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.33 no.3
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    • pp.159-165
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    • 1997
  • This paper presents the optimum dimension of 89 ton class stow-net vessel with stern-fishing. The model of basic design is developed by using the optimization techniques referring to objective function and numerous constraints as follows; speed, fishing quantity, fishing days, catch per unit effort(CPUE), and weight/ratio of main dimensions, etc. Thus, the basic design of stow-net fishing vessel is built up by using the optimization of the design variables called the economic optimization criteria, and the objective function represents the criterion which is cost benefit ratio(CBR). The main conclusions are as follows. 1. S/W for decision of optimum hull size is developed in 89 ton class stow-net fishing vessel which is constructed with optimization of the design variables called the economic optimization criteria. 2. For optimum ship dimensions in 89 ton class stow-net fishing vessel, the hull dimensions can be obtained in the range of L= 27.3m, B = 6.6m, D = 2.80m, Cb = 0.695, T/D = 0.80, $\Delta$(displacement)=281.7ton with 10 knots.

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Fishery Resources off Youngkwang 1. Species Composition of Catch by a Stow Net (서해 영광 연안 수산자원 I. 주목망 어획자원의 종조성)

  • HWANG Sun Do;IM Yang Jae;KIM Yong Cheol;CHA Hyung Kee;CHOI Seung Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.5
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    • pp.727-738
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    • 1998
  • Seasonal species composition of fishery resources was determined using samples collected by a stow net from April 1995 through January 1996 at 9 stations off Youngkwang. Catch data obtained from a set net using strong tidal current could be used for a quantitative analysis of dominant species. Of the 98 species identified, assemblages were consisted of $52.0\%$ in fishes, $44.6\%$ in shrimps, $2.0\%$ in cephalopods, $1.4\%$ in crabs and <$0.1\%$ in gastropods. Thryssa kammalensis, Crangon hakodatei, Metapenaeus joynezi and Johnius grypotus predominated in abundance, consisting of $68\%$ in the number of individuals, The abundance and species composition fluctuated seasonally, and species could be distinguished by life history pattern with seasons. Seasonal variation in species composition was greater than the spatial variation in a sampling period, As the fine sediment was predominated in the study area, the species composition were significantly different from those of other coastal waters of West Sea, Korea.

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Seasonal variations in species composition by the stow nets and the stow net on boat fisheries in the Han River Estuary, Korea (한강 하구 해역에서 개량안강망 및 해선망으로 어획된 수산생물의 계절별 종 조성)

  • Oh, Taeg Yun;Lee, Jae Bong;Seo, Young Il;Lee, Jong Hee;Choi, Jung Hwa;Kim, Jung Yun;Lee, Dong Woo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.4
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    • pp.452-468
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    • 2012
  • Marine organisms were collected by the stow nets and the stow net on boat fisheries from April 2010 to November 2011 in the Han River Estuary and categorized as 126 species, 61 families, and 5 taxa. The species were consisted with 34 in Crustacea, 5 in Cephalopoda, 79 in Pisces, unidentified jellyfishes in Cnidaria, and Finless porpoise in Mammals. The major species were composed of fish and crustaceans in the Han River Estuary. The dominant species in Crustacea were Chinese ditch prawn (Palaemon gravieri), blue crab (Portunus trituberculatus), Ridgetail prawn (Exopalaemon carinicauda), and mantis crab (Oratosquilla oratoria), and those in Pisces were Korean anchovy (Coilia nasus), and Japanese grenadier anchovy (Coilia mystus). The length structures of the six dominant species have more than one mode in the Han River Estuary. It reflects that the species inhibit during a part of and/or whole lifetime in the Han River Estuary where they utilize as spawning and/or nursery grounds. Freshwater fishes were collected from station D where is the closest location to the Han River stream, and their appearances were well matched with the large amount of freshwater discharge due to flood periods. Principal components analysis (PCA) was carried out with species compositions and showed temporal and spatial differences by the variations of species.

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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Species Compositon and Seasonal Variations of Fishes Collected by Winged Stow Nets on Anchors off Namhae Island (남해도 연안해역에서 낭장망에 의해 어획되는 어류의 종조성 및 계절변동)

  • Heo, Seong-Hoe;Gwak, Seok-Nam
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.34 no.3
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    • pp.309-319
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    • 1998
  • Species composition and seasonal variations of fishes collected by winged stow net on anchors in the coastal water off Namhae Island was studied from May 1989 m April 1990. During the study period, a total of 56 fish species were collected. Engraulis japonicus, Conger myriaster, Trichiurus lepturus, Sardinella zunasi, Ammodytes personatus, and Thryssa kammalensis predominated. These six species accounted for 93.9% of the total number and 81.3% of the total biomass of fishes collected. Fishes collected by winged stow nets on anchors were primarily small fish species or early juveniles of large fish species. Both abundance and species composition of fishes changed with season. Seasonal peaks of number of species occurred in spring and fall, while those of number of individuals and biomass occurred in spring. The lowest number of individuals and biomass were observed in winter. Low species diversity indices were observed in summer. These low diversity indices in summer were mainly due to predominance of E. japonicus which accounted for approximately 90% of all fishes collected. More species and greater biomass were collected during nighttime.

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A Study on the Multi-gear and Multi-species Fisheries Assessment Models in Korean Waters II. Single-species by Multiple Fisheries (한국 근해 복수어구 및 다종어업 자원 평가모델 연구 II. 복수어구에 의한 단일 어종 자원의 이용)

  • SEO Young Il;ZHANG Chang Ik
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.4
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    • pp.359-364
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    • 2001
  • This paper presents case studies on the multi-species fisheries in Korean waters, Multi-species fisheries were divided into two types, that is, multi-species by a single fishery and single species by multiple fisheries. For the case of single species by multiple fisheries, the small yellow croaker stock caught mainly by the Korean pair trawl fishery and the Korean stow net fishery was selected. This approach uses both standardized fishing efforts for the two fisheries by a general linear model and some data for the economic analysis, and then estimates maximum sustainable yield (MSY), maximum economic yield (MEY) and fishing efforts for MSY and MEY, An analysis of interaction aspects between pair trawl and stow net fisheries was carried out to predict the optimal level of fishing effort from the economic point of view, which gives the largest benefits to the two fisheries.

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Fishery Resources off Youngkwang II. Species Composition of Catch by a Otter Trawl (서해 영광 연안 수산자원 II. Otter Trawl 어획자원의 종조성)

  • HWANG Sun Do;IM Yang Jae;SONG Hong In;CHOI Yong Suk;MOON Hyung Tae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.5
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    • pp.739-748
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    • 1998
  • Demersal fishery resources were collected by an otter trawl in May, August and November 1996 at 9 stations off Youngkwang. And they were compared with the data obtained by a stow net, Of 73 species identified, assemblages were consisted of $63.0\%$ in fish, $14\%$ in shrimps, $14\%$ in crabs, $5\%$ in cephalopods and $3\%$ in gastropods. Johnius grypotus, Palaemon gravieri, Crangon hakodatei, Cynoglossus joyneri, Collichthys niveatus predominated in abundance, consisting of $64.4\%$ in the number of individuals. Catch by an otter trawl consisted mainly of demersal fishery resources, while catch by a stow net consisted mainly of pelagic fishery resources.

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