• Title/Summary/Keyword: a stow net

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Study on the Improvement of Stow Net Fishing Technique and the Enlargement of Fishing Ground to the Distant Waters - 3 . Field Experiment on the Efficiency of Newly Designed Net and the Stern Operation System (안강망어법의 개량과 어장의 원해로의 확대를 위한 연구 - 3 . 시험어구의 전개성능과 선미식 어업방법에 관한 해상시험 -)

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    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.25 no.2
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    • pp.75-81
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    • 1989
  • In this paper, the authors describe on the field experiment of the newly designed actual stow net, standing on the result of the model experiment to examine the performance of the conventional net and the newly designed net, presented in two previous reports of this series. Concurrently the additional experiment to find out the possibility of changing of operating system from the side to the stern was carried out. 1. Fundamental shape of the experimented net was 20 times aslarge asthe newly designed model net. Performance of the net was detected by using two ultrasonic echo sounders: one was set downward at the top-most spreader of the shearing device to detect the opening height of the device from the sea bed, and the other sidewise at the starboard top-most spreader to detect the top-most opening width of the devices. Opening height of the newly designed net showed about 3m smaller than the conventional net at slow current of 0.6m/sec and less but it overcome 1m at speedy current of 0.8m/sec and more. Opening width of the newly designed net was 1.4 times as large as that of the conventional net, ant the front projection area of the newly designed net mouth was estimated as 1.3~1.6 times as large as that of the conventional net. 2. The experiment on the stern operating system was tightly limited by the structure of the ship employed in the experiment, which was a stern trawler of 2275 GT. The ship confronted by the wind with main anchor, while the net was put over the stern slipway and the hauling line of shearing device was operated through the top rollers of gallows. The experiment was very suggestive in the view point to mechanize the operating system, and so to decrease the man power except the following question. The of bow-stern line of ship, and that of net is much different.

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A Study on the Transition Process of Fisheries Industry, Fisheries Institute of West Coast of Korea (Around the Gogunsan Islands and adjacent Area) (우리 나라 서해안(西海岸)의 수산업(水產業) 및 수산교육기관(水產敎育機關)의 변천과정(變遷過程)에 관한 사적(史的) 고찰(考察) (고군산(古群山) 군도(群島)의 인접지역(隣接地域)을 중심(中心)으로))

  • Lee, Kil-Rae
    • Journal of Fisheries and Marine Sciences Education
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    • v.11 no.1
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    • pp.24-42
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    • 1999
  • I have studied historical transition process of fisheries industries, fisheries Institute in abreast of developing fisheries industries of west coast of Korea since 1910 year with regard to the Gogunsan Is. The results were summarized as follows. In 1910 year, fishery industry has been carried out shifting fishing gear e.g set-net in shallow waters, small stow net, small seine net adapting to the tophorgrapical feature, shape of coast, oceanic condition, however, the fishing gear and fishing method were undeveloped, so that, Japanese fishermen had been exploited fisheries resources penetrating the fishing ground. Most important species were lot of captured croaker, cod, spanish mackeral, sea abream, herring in coastal sea. nowaday, squid, anchovy, shrimp, crab, pompret were much captured. The species were captured in 18 century were not captured. It is rarely than that period. Fishereis aquatic culture had been not farmed till 1960 year, but sea laver, shrimp, crab, had been breeded 1970 year also, the fresh water fish e.g. eel, cat-fish had been breeded activately. The fisheries processing industry were composed of salt. icing, dry, method. the salted fish industry had been prevailed at Gangyng, Kwangchon, Kunsan, Julpo comparatively. The fisheries institute had been established at Kunsan at first, but institute established in other region had been abolished in a short time. This phenomenon was related with development of fisheries resources. The western coast fisheries industries had been wasted of decreasing of fisheries resources, variation of environment. Accordingly, the study of preserving the marine resources. educated man power who engaged in fisheries field have to accomplish. Sea was dying with reason of loss of mud in west coast factory waste, waste of life the increase of accident of sea polluted, each illegal fishing industry physical and chemical reason etc. in this respect, Kusan maritime college, fisheries developing agency, institute have to take important role for developing fishing industry.

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Study on the Improvement of Stow Net Fishing Technigue and the Enlargement of Fishing Groung to the Distant Waters 2 . Model Experiment on the Newly Designed Gear (안강망어법의 개량과 어장의 원해로의 확대를 위한 연구 - 2 . 새로 설계된 어구의 모형실험 -)

  • Lee, Byeong-Gi;Kim, Jin-Geon;Lee, Ju-Hui
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.25 no.1
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    • pp.6-11
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    • 1989
  • Some distinctive defects in the conventional stow net were examined and presented in the previous report of this series. To find out the more effective gear by correcting the defects, the authors carried out another experiment by using a newly designed gear. 1. Special features of the newly designed gear are: (1) stretched width of front end on top, bottom and side panel are decreased 20%, on the other hand, the frank of the panels are increased 10% compared with the conventional gear. Front end of top and bottom panels are bias cutten up to 20% of the length of panels. (2) Length of the head rope and ground rope are shortened 6% by changing of the shape of the top and bottom panels. (3) Lacing lines are attached to four longitudinal seaming lines with suitable hanging ratio. (4) Stretched height of the shearing device were shortened 17%, and the buoyancy on top of the device were increased 20%. (5) Length of the biforked pendants were arranged to be shorter on top-most and bottom-most ones, and loner on middle ones. 2. The observed result can be expressed as (1) Wrinkles in the front end of top panels are removed and fringe line of panels become smooth. (2) Opening height of mouth is observed 3% higher than that of the conventional gear. (3) Opening width is 1.5 to 1.6 times wider than that of the conventional gear. (4) Hydrodynamic resistance is decreased 10%-17%.

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Rescue, rehabilitation and release of finless porpoise (Neophocaena asiaeorientalis) in Korea (한국 상괭이(Neophocaena asiaeorientalis)의 구조, 재활, 방류)

  • KIM, Moon-Jin;SOHN, Hawsun
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.3
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    • pp.861-871
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    • 2016
  • The coastal water of Korean Peninsula is the major habitat for finless porpoises. However, hundreds of finless porpoises are currently caught incidentally by stow-net fishery every year. To prevent the mass mortality of finless porpoises and conserve marine animals, Busan Aquarium has been designated as a "Marine Life Ex-Situ Conservation Institution and Marine Animal Conservation Center," and Cetacean Research Institute, under the National Institute of Fisheries Science have started RRR (rescue, rehabilitation and release) project together since 2011. From 2012 to 2013, four individuals of finless porpoises had been rescued and two of them finally released to their original habitat after fully recovered in July 2013. As a result, according to growth curve of finless porpoise of Korea more than 140 cm of body length, 38 kg of total weight referred to adult, results of observation of the change in the hormone revealed that mating time of finless porpoises is January, Jun and July. To become the initial institution which rescues, treatment, husbandry and releases finless porpoise in Korea.

Cases of Fishery Co-management in Korea : 'Fishery Closures' of Fisheries Cooperatives (어업인 참여 수산자원관리 운영에 대한 연구 : 수협의 휴어제 운영 사례)

  • Lee, Chang-Soo;Lee, Sang-Go
    • The Journal of Fisheries Business Administration
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    • v.49 no.3
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    • pp.29-47
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    • 2018
  • The primary purpose of this paper is to introduce the cases of fishery co-management, particularly in Korea. In recent, the fishery co-management between the government and fishermen has been brought an important shift of paradigm in a part of Korean fishery management policy. In case of Korea fisheries area, three fisheries cooperatives(which refer to purse sein fishery, trawl fishery, stow net fishery) have a minority of co-management programs. Generally, the main method of fishery co-management programs is 'Fishery Closures' among the programs, and others are restriction of fishing gear and fishermen educations. In spite of the efforts and time consumes of Korean government and fisheries cooperatives, much to our regret that it is hard to confirm visible results in an increased amount of fisheries resources so far because of the time constraint, namely fishery co-management programs have been conducted just since two to three years before. However, what's certain is that fishery co-management programs make it possible to positively effect on both of area in fishermen and fisheries resources. Accordingly, it is necessary that Korean government and fishermen should extend the fishery co-management to other fishery areas as soon as possible we can in order to efficiently reduce administrative costs and effectively reserve fisheries resources.

An Empirical Analysis on Factor Productivity of Coastal Fishery (연안어업 요소생산성에 관한 실증연구)

  • Kim, Chang-Wan;Eh, Youn-Yang;Lee, Jin-Soo;Song, Dong-Hyo
    • The Journal of Fisheries Business Administration
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    • v.53 no.1
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    • pp.1-16
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    • 2022
  • This paper aims to propose a new systematic approach to analyze the factor productivity and to investigate those characteristics of factor productivity in operational and managerial perspectives. The Cobb-Douglas production function is adopted to estimate the labor and capital productivity. In estimating those productivities the data of The Research on the Actual Condition of Coastal Fisheries (RACF), especially those of Jeon-Nam Province are used. The statistical analysis of RACF data shows that the characteristics are a little bit different between labor and capital of the operational equipment in the coastal fisheries. The Cobb-Douglas type production function is useful in estimating the factor productivity, especially in case of 'coastal Stow-net fishery' even though the limited data is used. However, in case of 'trap fishery,' the Cobb-Douglas production function appears to have some limitations in estimation. This implies that estimating the factor productivities in fisheries employing broad perspectives and various methods are needed.

A basic research on risk control measure for reducing the fishermen's occupational accident in offshore and coastal fishing vessel (연근해 어선원 재해 현황과 저감 대책 마련을 위한 기초 연구)

  • Kim, Wook-Sung;Cho, Young-Bok;Kim, Seok-Jae;Ryu, Kyong-Jin;Lee, Yoo-Won
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.4
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    • pp.614-622
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    • 2014
  • The aim of this study is to research attributes of fishermen's occupational accidents for investigating the measure of risk control on situational condition in the Korean offshore and coastal fishing vessel. Using data of fishermen's occupational accidents are from National federation of fisheries cooperatives for 2013. The results were as belows; Occupational accident occurrence rate was 29.5‰, slips & trips and struck by object and contact with gear were shown severe occurrence pattern. Occupational accident occurrence rate of offshore fisheries was 130.2‰, coastal was 16.9‰, specially the risk rates were severely high in several type of danish seine, stow net and offshore trap. Death rate by accidents was 10.6‰ and by fall into the water in occurrence pattern was 5.5‰.

Age Studies on the Butter Fish Population from Southwestern Waters of Korea

  • Han, Pyung Chin
    • 한국해양학회지
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    • v.8 no.2
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    • pp.68-74
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    • 1973
  • The present paper concerns the age determination and growth of butter fish, Pampus argenteus from the southwestern waters of Korea by otolith reading. 743 specimens taken by stow-net in the southern part of the Yellow Sea and northeastern part of the East China Sea during the period from October 1972 to September 1973 were examined. Results of the study are summarized as follows: 1. Sex ratio of females to males was found to be 2:1. 2. Ring marks on the otolith were found to be formed twice a year, once during the period of January-May and the other time in September. 3. The Lee's phenomenon was observed on the otolith sample. 4. The relationship between the radius of otolith(R) and fork length(L) was found to be as follows: R=0.3069+0.0133L 5. Calculated fork length at the time of otolith ring formation are found to be as follows:I-ring,71.67mm; II-ring, 125.05mm; III-ring, 168.65mm; IV-ring, 201.74mm; V-ring, 225.80mm; VI-ring, 240.84mm. 6. Maximum fork length calculated according to the diagram of Walford's growth transformation was found to be 281.5mm. 7. Growth curve, when related to the von Bertalanffy's equation, was laid out as $L_{t}=281.5[1-e$^{-0.674(t-0.128)}]$

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Oceanographic Conditions of Eishing Ground of Yellow Croaker (Pseudosciaena polyactis) in Korean Waters (한국연근해 참조기 (Pseudosciaena polyactis Bleeker) 어장의 해황 특성)

  • BAIK Chul-In;CHO Kyu Dae;LEE Chung Il;CHOI Kwang-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.3
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    • pp.232-248
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    • 2004
  • In order to utilize fisheries resources under a joint management scheme with adjacent nations, as well as detecting of fishing grounds, the factors which influence yellow croaker (Pseudosciaena polyactis) in Korean waters were studied using historical catch per unit effort and oceanographic data. The main fishing ground near Cheju Island was located along the thermal front formed between the Yellow Sea Bottom Cold Water (YSBCW) and northward moving warm current. When the YSBCW (index temperature: $10^{\circ}C)$ strongly extended southward, the fishing condition were worse than average. Especially, low temperatures greatly influenced stow net fisheries, which were operated in the deep water layer The concentration and dispersal of fishing ground and catch coincided with oceanographic features and the seasonality of water masses.

Maturity and Spawning of the Olive Flounder, Paralichthys olivaceus in the West Sea of Korea (서해 연안에 서식하는 넙치(Paralichthys olivaceus)의 성숙과 산란)

  • Su Jin Koh;Tae Hyoung Roh;Dong Hyuk Choi;Byeong Il Youn;Maeng Jin Kim;Seung Hwan Lee
    • Korean Journal of Ichthyology
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    • v.36 no.3
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    • pp.253-262
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    • 2024
  • This study revealed the reproductive biology of the Olive Flounder, Paralichthys olivaceus, in the middle of the West Sea of Korea. We collected samples using stow net and drag net fisheries in coastal waters from January to December 2023. Monthly gonodosomatic index and maturity stage results showed that the spawning period was April to June for females and March to June for males. Females grew faster than the males. The fecundity ranged from 90,387 to 994,658 number of eggs, and the relationship between TL and fecundity (F) was 0.01TL2.4896 (R2=0.2862). The gonadosomatic index (GSI) exhibited its highest values in May for females and in March for males, coinciding with the primary spawning period. The total length required for 50% sexual maturity was determined through a logistic regression model and the females was estimated to be 49.4 cm and the males was estimated to be 36.5 cm.