• Title/Summary/Keyword: Fishing Method

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A study on the forecasting biomass according to the changes in fishing intensity in the Korean waters of the East Sea (한국 동해 생태계의 어획강도 변화에 따른 자원량 예측 연구)

  • LIM, Jung-Hyun;SEO, Young-Il;ZHANG, Chang-Ik
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.54 no.3
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    • pp.217-223
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    • 2018
  • Overfishing capacity has become a global issue due to over-exploitation of fisheries resources, which result from excessive fishing intensity since the 1980s. In the case of Korea, the fishing effort has been quantified and used as an quantified index of fishing intensity. Fisheries resources of coastal fisheries in the Korean waters of the East Sea tend to decrease productivity due to deterioration in the quality of ecosystem, which result from the excessive overfishing activities according to the development of fishing gear and engine performance of vessels. In order to manage sustainable and reasonable fisheries resources, it is important to understand the fluctuation of biomass and predict the future biomass. Therefore, in this study, we forecasted biomass in the Korean waters of the East Sea for the next two decades (2017~2036) according to the changes in fishing intensity using four fishing effort scenarios; $f_{current}$, $f_{PY}$, $0.5{\times}f_{current}$ and $1.5{\times}f_{current}$. For forecasting biomass in the Korean waters of the East Sea, parameters such as exploitable carrying capacity (ECC), intrinsic rate of natural increase (r) and catchability (q) estimated by maximum entropy (ME) model was utilized and logistic function was used. In addition, coefficient of variation (CV) by the Jackknife re-sampling method was used for estimation of coefficient of variation about exploitable carrying capacity ($CV_{ECC}$). As a result, future biomass can be fluctuated below the $B_{PY}$ level when the current level of fishing effort in 2016 maintains. The results of this study are expected to be utilized as useful data to suggest direction of establishment of fisheries resources management plan for sustainable use of fisheries resources in the future.

Fishing gear and method and improvement of regulation of the middle sized trawl fishery in the East Sea of Korea (동해구중형트롤어업의 어구어법 및 제도 개선에 관한 연구)

  • JANG, Choong-Sik;SONG, Won-Sang;KANG, Myoung-hee;CHO, Youn-Hyoung;KIM, Bo-Yeon;AN, Young-Su
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.2
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    • pp.162-168
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    • 2016
  • This study attempted to help determine Korean fishery policies by proposing improvement plans after examining the current regulations, fishing vessels, fishing gear and fishing methods of the middle sized trawl fishery in the East Sea for targeting only squid. In general, the size, engine horse power, and net length of the middle sized trawlers are between 50 and 60 GT, 1,200 and 1,600 PS, and approximately 165 m with four seamed trawl nets, respectively. While a jigging vessel attracted squids using lights, the trawler approached a jigging vessel. The trawler let the jigging vessel know its decision for fishing, and then jigging vessel rolled up jigs. The net of the trawler was casted at 45 degrees between the bow and the stern of the jigging vessel. Once the trawler towed close to the stern of the jigging vessel upon its passing of the jigging vessel, the bow of the trawler turned 45 degrees left again. Then, squid aggregations were entered into the net. When the cod end was passed a light vessel, the trawler hoisted the net up to the otter board. Then the trawler turned 180 degrees. It repeated three to five times of fishing operations as the previous method. We recommend that the regulations allow nineteen side trawlers to catch like stern trawler, as well as the cooperative trawler and jigging vessel operations.

A Study on the Vibration Analysis of a Deckhouse of Fishing Vessel (어선의 갑판실의 진동 해석법에 관한 연구)

  • 배동명
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.27 no.3
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    • pp.193-210
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    • 1991
  • For the deckhouse or superstructure, attention is directed to the reduction of vibration from a human susceptibility point of view. The two basic requirements for obtaining a low vibration level in the accommodation are to ensure that excitation forces from propeller and/or main engine are small and to avoid resonance excitation of the hull and superstructure. In recent years increased attention has been directed towards the problems of vibration and noise in deckhouse, which have caused major problems with regard to the environmental quality in the living quarters for crews. Accordingly, in this paper, the characteristic of the vibration of deckhouse of fishing boat, of which the length/height ratio is also relatively high, are studied systematically with regard to the shape and modelling of deckhouse based on finite element method of 1-dimensional, 2-dimensional and 3-dimensional model. This study is divided into 4-part. 1st part is the global deckhouse vibration, 2nd part is the local deckhouse vibration, 3rd part consists of the estimation for stiffness of foundational support and 4th part is the application to TUNA LONG LINER of 416 ton class. For the global vibration analysis, the severity of the vibration depends on the longitudinal shear and bending stiffness of the deckhouse, on the vertical deckhouse support(fore, aft and sides). However, even if the design is technically sound, vibration problems may arise due to vertical or longitudinal hull girder or afterbody resonances. Author applied the method of this study to the analysis of, deep-sea fishing vessel of G.T. 416 ton class with relatively low height and long deckhouse, and investigated the vibrational characteristic of the fishing vessel with earlier structural feature. According to this investigation, the vibration, response of above vessel was confirmed of which main hull and deckhouse behave as one body. It is at the bottom of vibrational trouble which a accommodation part of the fishing vessel is raised, that is the local vibration for side wall, fore-aft wall and deck plate of deckhouse rather than thief fect of fore-aft vibration of deckhouse for above fishing vessel. and the resonance of main hull, deckhouse and driving system such as the main engine, propeller in exciting source is mainly brought up as the trouble.

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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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A Study on Nutrients Intakes, Body Composition and Hematological Status of High School Girls in Fishing and Urban Areas (어촌과 도시지역 여고생의 영양실태, 체조성 및 혈액성상에 관한 연구)

  • 황금희;허영란;임현숙
    • Korean Journal of Human Ecology
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    • v.1 no.1
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    • pp.81-93
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    • 1998
  • The purpose of this study was to examin height, weight and body composition nutrient intakes and serum lipids for high school girls in urban and fishing area. The subjects consisted of 78(44 fishing and 34 urban) high school girls aged in average 17.3 and 17 years. Their dietary intakes were assesed for 1 day by means of 24 hours dietary recall method. Concentrations of serum lipids, percentage of body fat and volume of total body water were measured. The mean energy intake of the subjects were 1431 ㎉ in fishing and 1659 ㎉ in urban area. The subjects in fishing area(urban) consumed 58(67) g protein, 27(36) g lipid, 459(634) mg calcium, 676(945) mg phosphorous, 11(14) mg iron, 786(574) RE retinol, 2.8(3.6) mg tocopherol, 0.9(1.0) mg thiamin, 1.2(1.1) mg riboflavin, 16.9(20.5) mg niacin and 64.1(92.8) mg ascorbic acid, respectively. Energy, calcium, iron and tocopherol intakes were lower than the Korean RDA in both girls. The mean percentage of fishing girls were 19.8% and significantly lower than 25.6% in urban. These values seem to fall in the desirable range in fishing girls, but high school girls in urban is seemed to overweight. The mean saturated fatty acid(SFA), monounsaturated fatty acid(MUFA), polyunsaturated fatty acid(PUFA) and dietary cholesterol(Chol) intakes were 7.3 g, 8.1 g, 7.2 g and 263 mg for fishing girls were 13.1 g, 12.1 g, 9.1 g and 216 mg for urban girls respectively. The fat, SFA and MUFA intakes in fishing girls were significantly lower than urban girls. The P/M/S ratio was 0.9/1.1/1 for fishing, was 0.7/0.9/1 for urban. The mean serum triglyceride(TG), total cholesterol, HDL cholesterol, LDL-cholesterol concentrations were 77.7(61.8) mg/dl, 124.5(142.3) mg/dl, 59.3(22.4) mg/dl and 49.6(107.8) mg/dl in fishing girls(urban girls), respectively. All of these values seem to fall in the desirable range but HDL-chlesterol concentrations in fishing girls were significantly higher than urban girls and LDL-cholesterol concentrations in fishing girls were significantly lower than urban girls. There were positive correlations between body fat percent and total cholesterol or LDL-cholesterol concentration : negative correlations between between body fat percent and HDL-cholesterol concentration : positive correlation between fat intake and LDL-cholesterol concentration : negative correlations between serum HDL-cholesterol concentration and fat or SFA or MUFA intakes. (Korean J Human 1(1) : 81~93, 1998)

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Analysis of the working characteristics of the skipper and risk factors of marine accident in Korea coastal composite fishing vessels (연안복합어선 선장의 업무 특성과 해양사고 위험요소에 대한 분석)

  • KIM, Min-Son;HWANG, Bo-Kyu;CHANG, Ho-Young
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.2
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    • pp.152-161
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    • 2019
  • This research carried out a study on the job characteristics of the skipper of the coastal composite fishing vessels in order to find a way to prevent the ship collision caused by the highest human error among the marine casualty of fishing boats. Video observation was used as the research method in which six CCD cameras were installed on the vessel to collect image data and data extracted from the image were analyzed to derive the results of the functional activity of skipper according to the fishing operation process of experimental fishing vessel. The results are as follows. The working process of the experimental fishing vessel consisted of navigation for fishing ground, setting line, waiting for hauling line, hauling line and navigation to homeport. In these processes, the skipper was performing watchkeeping in the wheelhouse in which he carried out a single task, a dual task that performed two tasks simultaneously, and a triple task that performed two or more tasks simultaneously. In addition, one of the risk factors causing the collision was a no watchkeeping in the wheelhouse for navigating for fishing ground, waiting for hauling line, and hauling line at 25.4%, 64.6% and 0.3%, respectively among the marine casualty while drowsiness caused 1.2% of the marine casualty in navigating for fishing ground. Concurrent tasks that simultaneously perform two or more tasks that can overlook any other important duties while carrying out watchkeeping in the wheelhouse include 51.3% of navigation for fishing ground, 81.9% of setting line, 19.0% of waiting for hauling line, 87.9% of hauling, and 88.7% of navigation to homeport. The above concurrent tasks yielded an average of 66.1%. Experimental fishing vessels are required to focus on ship handling operations related to fishery operations, and the skipper is assigned more activities and attention to fishery related tasks. Therefore, it is considered desirable to build a collision prevention system that is appropriate to the characteristics of the skipper's work, escaping from transferring the responsibility of ship collision to the skipper completely.

A Comparative Study of the Methods to Assess Occupational Noise Exposures of Fish Harvesters

  • Burella, Giorgio;Moro, Lorenzo
    • Safety and Health at Work
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    • v.12 no.2
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    • pp.230-237
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    • 2021
  • Background: Noise-induced hearing loss is a well-known occupational disease that affects many fish harvesters from many fisheries worldwide, whose risk factor is prolonged exposure to hazardous noise levels. To date, academic research activities and regulatory bodies have not provided any comparative analysis among the existing methods to assess noise exposure levels of fish harvesters. This paper provides a comparison of four relevant assessment methods of noise exposure, examining the results of a measurement campaign performed onboard small fishing vessels from Newfoundland and Labrador. Methods: We traveled onboard 11 vessels engaged in multiple fisheries from Newfoundland and Labrador and performed extensive noise exposure surveys using the simplified International Maritime Organization method, the full-day measurement method, and the two methods provided by ISO 9612:2009, the task-based method and job-based method (JBM). Results: The results showed that the four methods yield similar values when the noise components are dominated by the engine and auxiliaries (steady-state sources); when noise components are dominated by the fishing gear, task-based method and the simplified International Maritime Organization method estimates are less accurate than JBM, using full-day measurements as baseline. Conclusion: The JBM better assesses noise exposure in small-scale fisheries, where noise exposure has significant variance and uncertainties on the exposure levels are higher.

Catch characteristic and present condition of by-catch & discard of trammel nets fishery in the East Sea (동해 삼중자망어업의 해역별 어획 특성과 혼획·투기 현황)

  • Bae, Bong-Seong;An, Heui-Chun;Park, Hae-Hoon;Park, Chang-Doo;Yang, Yong-Su
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.2
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    • pp.103-114
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    • 2010
  • For an effective management of fisheries resources, we need fisheries informations necessary for the establishment of reasonable fishing effort and TAC distribution. To study the present state of by-catch and discard of gill-net fishery in the East Sea, we carried out fishing research using trammel nets in the coastal sea of Susan-port (Yangyang), Jangho-port (Samcheok) and Hupo-port (Uljin). As a result, a total of catch of Susan was 259,172g and that of Hopo was 577,638g. Thus Catch of Susan was 1.49 times more than that of Hupo considering the number of used fishing gear. And catch of Janho was 7.4 times more than that of Susan considering the number of experiment. Two methods of by-catch analysis in this study were used, one method is standardizing of listed species catching possible in fishing license, another method is regarding catch species under 1% of total catch as by-catch. As a result of by-catch analysis of two method, by-catch rate of Susan was 6.55% and 5.87% respectively, that of Hupo was 44.70% and 5.24% and that of Jangho was 0.96% and 2.31%. Discard rate of fish in Susan, Hupo and Jangho were 1.59%, 3.42%, 2.23% respectively.

A Study on the Policy Directions of Korean Fisheries and Fishing Villages Applying Delphi Method (델파이 기법을 적용한 수산업·어촌 정책방향 연구)

  • Lee, Heon-Dong;Kim, Dae-Young
    • The Journal of Fisheries Business Administration
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    • v.49 no.3
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    • pp.67-83
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    • 2018
  • This study is aimed at finding policy directions for Korean fisheries and fishing villages by using Delphi method for fisheries experts. Fisheries experts have highly evaluated the achievements of fostering aquaculture industry, seafood export support measures, and natural disasters relief and recovery arrangements among the policies promoted as so far. And it was recognized that policies such as fishery resources management, creation and recovery of fishery resources, improvement hygiene and seafood safety, and provision young fishermen with training and capacity building will be important. Future megatrends, for example changes in food consumption pattern, climate change, and demographic structure changes are expected to have a significant impact on fisheries and fishing villages. The Delphi survey indicates that the most important policy objective is to secure a stable fisheries production. In other words, fisheries policy in the future should be aimed at suppling sustainable seafood for popular consumption. Finding strategies and action plans that can achieve this goal will be an important policy issue. In conclusion, it is necessary that a number of fundamental researches carry out in Korea, which can lead to finding out a multifunctionality of fisheries and fishing village. In addition, it is important to expand the scope of fisheries policy, which can consider not only the fisheries producers but also seafood consumer's and young fishermen perspectives. Furthermore, it recommends that fishery policy needs to include fishery related industry as well as application of 4th industrial revolution technology to fishery.