• Title/Summary/Keyword: Offshore fisheries

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The relationship between fishing characteristics of Pacific bluefin tuna (Thunnus orientalis) and ocean conditions around Jeju Island

  • Shin, Ari;Yoon, Sang Chul;Lee, Sung Il;Park, Hee Won;Kim, Suam
    • Fisheries and Aquatic Sciences
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    • v.21 no.1
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    • pp.1.1-1.12
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    • 2018
  • Pacific bluefin tuna (Thunnus orientalis) is one of the commercially important species in Korea as well as other countries of the North Pacific. Korean offshore large purse seine fisheries targeting small pelagic fishes such as chub mackerel have caught T. orientalis temporarily in the east of Jeju Island. The catch of T. orientalis in March through June occupied approximately 60% of the total. The monthly catch around Jeju Island from 2004 to 2013 showed a negative correlation (r = - 0.755, p < 0.01) with the seawater temperature at 50 m and had a significant positive correlation (r = 0.856, p < 0.01) with the Pacific Decadal Oscillation Index (PDOI). The highest catch and catch per unit effort (CPUE) of T. orientalis around Jeju Island occurred either when the seawater temperature ranged between 15 and $16^{\circ}C$ at 50 m or when the catch was taken near the frontal area where two water masses from offshore and coastal areas collide. The length of T. orientalis caught around Jeju Island from 2004 to 2013 ranged from 19 to 193 cm in fork length (FL). The time series of the monthly mean FL of T. orientalis had a negative correlation (r = - 0.592, p < 0.01) with the seawater temperature at 50 m and had a significant positive correlation (r = 0.668, p < 0.05) with PDOI.

A Study on Accelerating Marine Equipments Industry for Enforcing Competitiveness of the Offshore Plants Industry (해양플랜트산업 경쟁력 강화를 위한 조선기자재산업 고도화에 관한 연구)

  • HA, Chang-Seung;JUNG, Dae-Hyun
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.5
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    • pp.1369-1379
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    • 2015
  • This study attempted an AHP analysis through interview with experts in the industries and questionnaire survey on recognition of organization members and future strategic development direction in order to upgrade shipbuilding equipment industries to marine plant equipment industries. Key research results are as follows. First, according to analysis on relative priority between three aspects on acceleration of shipbuilding equipment industries, importance was shown in the order of acceleration of internal competence, acceleration of manufacturing technology, and acceleration of supply chain, which means that the aspect on acceleration of internal competence had relatively higher importance. Second, as for relative importance of detailed item evaluation per respective aspect, it was found that development of core competencies was high from the aspect on acceleration of internal competence, higher value-addition was high from the aspect on acceleration of manufacturing technology, and IT infrastructure construction was high from the aspect on acceleration of supply chain.

Control of Dynamic Reaponses of Huge Structures for Ocean Space Utilization in Waves (해양공간이용구조물의 응답제어)

  • Goo, Ja-Sam;Hong, Bong-Ki
    • Journal of Ocean Engineering and Technology
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    • v.5 no.2
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    • pp.156-156
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    • 1991
  • A numerical procedure is described for predicting the dynamic responses of combined systems of floating breakwaters and huge offshore structures supported by a large numer of the floating bodies in waves. The hydrodynamic interactins among tatal floating bodies are taken into account in their exact form within the context of linear potential theory. Wave control effects are discussed with both hydrodynamic interactions and hydrodynamic-structure interaction effects. The method presented is applicalbe to combined systems of floating breakwaters and huge structures for ocean space utilization for which a number of practical uses are seen in the future.

Distribution and Abundance of Planktonic Shrimps in the Southern Sea of Korea during 1987-1991

  • Park, Won-Gyu;Ma, Chae-Woo;Hong, Sung-Yun;Lee, Ki-Won
    • Fisheries and Aquatic Sciences
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    • v.12 no.3
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    • pp.240-248
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    • 2009
  • Distribution and abundance of planktonic shrimps were studied in the southern sea of Korea from 1987 to 1991. Nine species of five genera belonging to three families were identified. Of these, Leptochela sydniensis and Lucifer intermedius were predominant species and Lucifer penicilifer and Lucifer typus were common species. Remaining five species, Acetes chinensis, Leptochela gracilis, Lucifer chacei, Process wheeleri and Sergestes similis occurred sporadically and rarely. The distribution pattern of planktonic shrimps varied with species and sampling periods. L. intermedius occurred abundantly along inshore waters. L. penicilifer and L. typus appeared in both inshore and offshore waters, but more abundantly in offshore waters under influence of the Tsushima Current. In conclusion, the distribution patterns of planktonic shrimps may be related with hydrographic characteristics and seasonality in the southern sea of Korea.

Distribution Characteristics of Fishes by a Bottom Trawl in the Jointly Controlled Waters of the East China Sea (동중국해 한일공동수역에서 저서 어획물의 분포특성)

  • Kim, Min-Seok;Kim, Dong-Su
    • Journal of Fisheries and Marine Sciences Education
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    • v.22 no.3
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    • pp.330-340
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    • 2010
  • This study was investigated the species composition of demersal fishes by a bottom trawler GAYA, in order to be used basic data for resources management of fishery in the jointly controlled waters of the East China sea. We caught 52 species, 1,167 individuals and 186.171kg in biomass in summer, and 1,924 individuals and 200.871kg in biomass in winter The first dominant species in individuals in summer was Glossanodon semifasciatus, and in biomass was Dentex tumifrons. But that in winter was Ovalipes punctatus in both individuals and biomass. It was a special phenomenon that crustacea was to be the first dominant species compared with general offshore fishery in Korea. Catch per unit effort (kg/hr) of bottom trawl in winter was higher than that in summer. There was also big difference by station in the diversity index, the evenness index and the dominant index.

Optimal Design of Mooring Steel Pile for Submersible Fish Cage (부침식 가두리 계류용 말뚝의 최적설계)

  • 이나리;김현주;최학선;류연선
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.2
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    • pp.201-208
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    • 1999
  • To develop a new fish cage which is required for offshore or moving cage culturing system has been gradually increased against being closely dense of fish cage in shallow water. Though submersible fish cage culturing system is essential technology for converting from shallow water into the offshore, it was pointed out the serious problem about stability of which are sinking and floating state. This study is presented conceptual design of submersible fish cage centered with a mooring steel pile to acquire stability and faculty. Design of mooring steel pile for submersible fish cage culturing system needs to carry out optimal design of mooring steel pile for which much efforts are required. Formulation and optimal design process of submersible fish cage are organized into using Sequential Quadratic Programming method of numerical optimization. For submersible fish cage system centered with a mooring steel pile, process of the optimal design is proposed and the optimal solutions are obtained.

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A Study on Industrial Classification of Fisheries in Korea (우리나라 수산업의 산업적 분류에 대한 연구)

  • Kim, Sam-Kon
    • Journal of Fisheries and Marine Sciences Education
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    • v.20 no.1
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    • pp.23-35
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    • 2008
  • The purposes of this study are to analyze problems in industrial classification of fisheries in Korea and to suggest future directions. Based on a thorough review of relevant literature, the study proposes a five-level scheme for classifying fisheries. The highest level should be the fisheries industry, and the next highest level ought to be fisheries. The medium level should include fishing, aquaculture, and fishery service industries. At the fourth level, fishing is to be further divided into sea fishery and inland fishery, aquaculture into sea-surface aquaculture and inland aquaculture, and fishery service industries into integrated fishery service and fishery distribution service. The lowest level is the most detailed. At this level, sea fishery is split into deep sea fishery, offshore fishery, and coastal fishery; sea-surface aquaculture consists of sea aquaculture, seed production aquaculture, and food organism aquaculture; integrated fishery service is further classified into fishery-related service and fishery information service.

Feasibility of Red Tide Detection around Korean Waters using Satellite Remote Sensing

  • Suh, Young-sang;Lee, Na-kyung;Lee, hyun-Jang;Kim, Hak-gyoon;Kim, Bok-kee;Hwang, Jae-dong
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2003.05a
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    • pp.129-131
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    • 2003
  • Korea has experienced a Cochlodinium polykrikoides red tide 10 out of the last 10 years (1993-2002). This species of red tide has been experienced at least once by all the southern coast of the Korean peninsular and has been transported up the southeastern coast all the way to the northeastern coast since 1995. The impression is that red tide is spending and becoming more common not only in the nearest coastal water, but also in the offshore. (omitted)

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Estimating Optimal Harvesting Production of Yellow Croaker Caught by Multiple Fisheries Using Hamiltonian Method (해밀토니안기법을 이용한 복수어업의 참조기 최적어획량 추정)

  • Nam, Jong-Oh;Sim, Seong-Hyun;Kwon, Oh-Min
    • The Journal of Fisheries Business Administration
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    • v.46 no.2
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    • pp.59-74
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    • 2015
  • This study aims to estimate optimal harvesting production, fishing efforts, and stock levels of yellow croaker caught by the offshore Stow Net and the offshore Gill Net fisheries using the current value Hamiltonian method and the surplus production model. As analyzing processes, firstly, this study uses the Gavaris general linear model to estimate standardized fishing efforts of yellow croaker caught by the above multiple fisheries. Secondly, this study applies the Clarke Yoshimoto Pooley(CY&P) model among the various exponential growth models to estimate intrinsic growth rate(r), environmental carrying capacity(K), and catchability coefficient(q) of yellow croaker which inhabits in offshore area of Korea. Thirdly, the study determines optimal harvesting production, fishing efforts, and stock levels of yellow croaker using the current value Hamiltonian method which is including average landing price of yellow croaker, average unit cost of fishing efforts, and social discount rate based on standard of the Korean Development Institute. Finally, this study tries sensitivity analysis to understand changes in optimal harvesting production, fishing efforts, and stock levels of yellow croaker caused by changes in economic and biological parameters. As results drawn by the current value Hamiltonian model, the optimal harvesting production, fishing efforts, and stock levels of yellow croaker caught by the multiple fisheries were estimated as 19,173 ton, 101,644 horse power, and 146,144 ton respectively. In addition, as results of sensitivity analysis, firstly, if the social discount rate and the average landing price of yellow croaker continuously increase, the optimal harvesting production of yellow croaker increases at decreasing rate and then finally slightly decreases due to decreases in stock levels of yellow croaker. Secondly, if the average unit cost of fishing efforts continuously increases, the optimal fishing efforts of the multiple fisheries decreases, but the optimal stock level of yellow croaker increases. The optimal harvest starts climbing and then continuously decreases due to increases in the average unit cost. Thirdly, when the intrinsic growth rate of yellow croaker increases, the optimal harvest, fishing efforts, and stock level all continuously increase. In conclusion, this study suggests that the optimal harvesting production and fishing efforts were much less than actual harvesting production(35,279 ton) and estimated standardized fishing efforts(175,512 horse power) in 2013. This result implies that yellow croaker has been overfished due to excessive fishing efforts. Efficient management and conservative policy on stock of yellow croaker need to be urgently implemented.

A Study on the Public Acceptance of Offshore Wind Farm near Maldo (말도 인근 해상풍력발전에 대한 주민수용성 연구)

  • Park, Jaepil;Lee, Sanghyuk
    • New & Renewable Energy
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    • v.17 no.3
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    • pp.24-31
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    • 2021
  • Through 'The Renewable Energy 3020 Implementation Plan' for carbon neutrality, the government promised to raise the proportion of renewable energy generation to 20% and renewable energy installation capacity to 63.8% by 2030. Therefore, we plan to test a 5.5 MW offshore wind turbine near Maldo, Gunsan. In this project, we measure the level of public acceptance and perform ordinary least squares (OLS) regression analysis to show the determinants of public acceptance. The regression results are as followed. First, it is judged that the closer the distance to the offshore wind turbine, the more the economic effects considered by residents. Second, especially in Maldo, the experience of being discriminated from the Saemangeum project, is understood to have caused distrust in the surrounding fishing villages chief/Fisheries Cooperatives, converted into a local community effect. Finally, the policy implications are as follows. First, a bottom-up problem-solving method is required to improve public acceptance, based on the Living Lab. Second, the island community may be indifferent to the briefings or forums of outsiders. Therefore, a gradual approach is required through (in)formal channels based on reliability from a long-term perspective with nearby universities and research institutes using SamsØ Energy Academy.