• Title/Summary/Keyword: Coastal fishery

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A Study on the Building of Tuna Farming in Floating Offshore Wind Power Generation Field at East Sea (동해 부유식 해상풍력발전단지 내 참다랑어 양식장 조성에 관한 연구)

  • Choi, Gun Hwan;Kim, Mi Jeong;Jang, Ki Ho;Kim, Hyo Seon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.33 no.5
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    • pp.179-186
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    • 2021
  • We need measures that can come up with alternative about fishery living zone and enhance local acceptance for responding to the increase in the proportion of renewable energy production and construction of 12GW Offshore wind power according to Korea's Renewable Energy 3020 initiative and Korean-version New Deal. In this study, We suggest that differentiation plans of co-location model in connection with offshore wind power generation suitable for the East Sea. The East Sea is an optimal site for building of a floating offshore wind power generation(FOWPG) field. It is expected that economic effects like energy production, aquatic resource development and tourism industrialization by farming bluefin tuna which is high valued fish and suitable for offshore aquaculture on public waters in FOWPG field. And we can confirm that budget reduction, smart management by sharing operation management technology and increase in fishermen income.

Analysis on the fishing conditions of tuna purse seiner belonging to the Korea-Ghana joint venture in the Atlantic Ocean (대서양 한-가나 합작법인 소속 다랑어 선망어선의 조업실태 분석)

  • KWON, Ki-Jun;LEE, Chun-Woo;KIM, Hyung-seok;RYU, Kyung-Jin;LEE, Yoo-Won
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.57 no.3
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    • pp.194-204
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    • 2021
  • The research was analyzed the catch data of the five years (2016-2020) for six joint venture company tuna purse seiners in the Atlantic Ocean, with the aim of suggesting improvement measures for responsible and sustainable fishing according to changes of recommendation by International Commission for the Conservation of Atlantic Tuna (ICCAT) on the tropical tunas. In the last five years, the average catch of six tuna purse seiner gradually increased to 7,745 tons, 8,364 tons and 9,053 tons from 2016 to 2018, but decreased to 7,761 tons in 2019 and 6,214 tons in 2020. The reason for the decrease in fishing volume in 2019 and 2020 was the fluctuation of the formation of the cold water zone (22-23℃), and the total ICCAT convention area of FAD closure in January and February due to the expansion of the FAD closure area and poor free school catching during two months period, respectively. The analysis on fishing area showed that the percentage of fishing in the high sea was about 85% although the FAD closure area included the EEZ zone in coastal countries; the rise of the fishing license in coastal countries is also believed to be a factor. In order to overcome such situations and improve catching volume, it will be possible if excellent manpower is secured, school fishing is expanded, and the production of high value-added catch (purse seine special: PS).

Experiments on Stability of Tetrapods on Rear Slope of Rubble Mound Structures under Wave Overtopping Condition (월파조건에서 경사제 항내측 사면에 거치된 테트라포드의 안정성 실험)

  • Kim, Young-Taek;Lee, Jong-In
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.33 no.6
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    • pp.357-366
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    • 2021
  • In this study, hydraulic model tests were performed to investigate the stability of armor units at harbor side slope for rubble mound structures. The Korean design standard for harbor and fishery port suggested the design figures that showed the ratio of the armor weight for each location of rubble mound structures and it could be known that the same weight ratio was needed to the sea side and harbor side (within 0.5H from the minimum design water level) slope of rubble mound structures. The super structures were commonly applied to the design process of rubble mound structures in Korea and the investigation of the effects of super structures would be needed. The stability number (Nod = 0.5) was applied (van der Meer, 1999) and it showed that the armor (tetrapod) weight ratio for harbor side slope of rubble mound structures needed 0.8 times of that for sea side slope.

Realtime Detection of Benthic Marine Invertebrates from Underwater Images: A Comparison betweenYOLO and Transformer Models (수중영상을 이용한 저서성 해양무척추동물의 실시간 객체 탐지: YOLO 모델과 Transformer 모델의 비교평가)

  • Ganghyun Park;Suho Bak;Seonwoong Jang;Shinwoo Gong;Jiwoo Kwak;Yangwon Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.5_3
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    • pp.909-919
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    • 2023
  • Benthic marine invertebrates, the invertebrates living on the bottom of the ocean, are an essential component of the marine ecosystem, but excessive reproduction of invertebrate grazers or pirate creatures can cause damage to the coastal fishery ecosystem. In this study, we compared and evaluated You Only Look Once Version 7 (YOLOv7), the most widely used deep learning model for real-time object detection, and detection tansformer (DETR), a transformer-based model, using underwater images for benthic marine invertebratesin the coasts of South Korea. YOLOv7 showed a mean average precision at 0.5 (mAP@0.5) of 0.899, and DETR showed an mAP@0.5 of 0.862, which implies that YOLOv7 is more appropriate for object detection of various sizes. This is because YOLOv7 generates the bounding boxes at multiple scales that can help detect small objects. Both models had a processing speed of more than 30 frames persecond (FPS),so it is expected that real-time object detection from the images provided by divers and underwater drones will be possible. The proposed method can be used to prevent and restore damage to coastal fisheries ecosystems, such as rescuing invertebrate grazers and creating sea forests to prevent ocean desertification.

Experiments on Stability of Armor Rocks on Rear Slope of Rubble Mound Structures under Wave Overtopping Condition with Rectangular Crest Element (월파조건에서 직사각형 상치콘크리트가 설치된 경사제 항내측 사면에 거치된 피복석의 안정성 실험)

  • Young-Taek Kim;Jong-In Lee
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.35 no.5
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    • pp.102-108
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    • 2023
  • In this study, hydraulic model tests were performed to investigate the stability of armor units at harbor side slope for rubble mound structures. The armor units on the rear slope were rocks. The Korean design standard for harbor and fishery port suggested the design figures that showed the ratio of the armor weight for each location of rubble mound structures and it could be known that the same weight ratio was needed to the sea side and rear side slope of rubble mound structures. The crest elements were commonly applied to the design process of rubble mound structures in Korea and the investigation of the effects of super structures would be needed. The damage rate (S =2) was applied and the stable wave height was measured for each test condition. The results were suggested as the armor weight ratio of the rear side slope(armor rock) to the sea side slope (tetrapod) in relation to the relative crest height.

A study on Policy Direction for Restructuring of Korean Fisheries-Case Analysis of Selected Countries (어업구조조정 정책 방향에 관한 연구-외국사례 연구를 통한 분석)

  • Chae, Dong-Ryul
    • The Journal of Fisheries Business Administration
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    • v.41 no.1
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    • pp.129-156
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    • 2010
  • Well-deviced buyback programs may be detrimental to achieve sustainable fisheries. However, it is not difficult to find undesirable examples that the result of buyback program have no impact on fish stocks or the sustainability of the fishery. This paper discusses the problems and policy directions for successful restructuring of Korean marine fisheries through comparative analysis of selected cases from five main countries including Japan, Norway, Italy, Taiwan and Australia. From the analysis, this study demonstrated that Korean buyback program just pursue the reduction of boat number but passed over alleviation of the real ability in fishing industry. Although there were clear decrease of fishing effort in a certain parts of fisheries and some evidences of advancement in efficiency, it seemed hard to continue these effects because the Korean policy lacks consistency and coherence of systematic restructuring. To summary, four things are recommended for successful application of Korean buyback program; first is to establish the obvious goal of the program, second is to introduce downsizing in both fleet capacity and engine power, third is to conduct other management tools simultaneously to help resource restoration, and last, but not the least is to induce voluntary participation of fishermen providing opportunity to pursue their mutual interest.

A basic study on the improvement of the continuous type fishing system for largehead hairtail hand line in coastal area of Jeju island, Korea (제주도 연안 연속식 갈치채낚기 조획시스템의 개량에 관한 기초적 연구)

  • Kim, Byung-Yeob;Lee, Chang-Heon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.45 no.1
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    • pp.14-21
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    • 2009
  • This experimental study was carried out to obtain the base data for saving the man power in the fishing operation of largehead hairtail hand line by using the continuous type hand line system with a rotary device which could make a main line move automatically. In order to solve the twists and entangling on the main line happened during operating test, the resistance board was suspended at the end of the main line at sea. As the result, there were no problems of tangling and so on due to up and down moving of a main line. According to the control of a fixed angle of guide roller, it was possible to prevent the main line to be separated from a side roller and a guide roller. In addition, PVC tube between a guide roller and a side roller enabled a main line to be moved smoothly without any entanglement.

Operating performance of squid jigging vessel using the LED and metal halide fishing lamp combination (LED와 메탈핼라이드 집어등을 겸용한 오징어채낚기 어선의 조업 성능)

  • An, Heui-Chun;Bae, Jae-Hyun;Bae, Bong-Seong;Park, Jong-Myung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.49 no.4
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    • pp.395-403
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    • 2013
  • Fishing efficiency of the squid jigging vessel using the LED and metal halide fishing lamp combination was analyzed to reduce the cost for fishing operation utilizing the fishing light system for high degree of efficiency in the squid jigging fishery (one of the representative coastal and offshore fisheries in Korea). This study aims to improve the nature of existing LED lamps and to develop fan-shaped LED lights having 180W of power and ${\pm}45^{\circ}$ angle of light intensity distribution. The marine experiment for making a comparison of their fishing efficiency was tested by a 9.77 tons fishing vessel from Oct. through Dec. 2012. As a result, experimental fishing vessel showed slightly higher fishing efficiency than the average of metal halide lamp-equipped vessel and 20% energy savings. This means that the combination of LED and metal halide lamps would provide an efficient way to lower energy consumption while maintaining fishing efficiency.

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.

A Study on a Bycatch of the Gape Net in Jindo Area of Jeollanam-do (전남 진도지역 낭장망 어업에 있어서 혼획 연구)

  • Kim, Seong-Hun;Park, Chang-Doo;Park, Seong-Wook
    • Journal of Fisheries and Marine Sciences Education
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    • v.24 no.2
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    • pp.137-145
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    • 2012
  • In order to survey the conditions of bycatch and discards for a gape net, a series of filed surveys was carried out total 10 surveys on two gape nets operated in the coastal area of Jindo during July to November 2008. The all catches in each survey were measured the body length, weight after sorted species. The analysis of catch data was conducted to separate 'first operation' and 'general operation'. In this study, the first operation defined as hauling the fishing gears that soaked over 10 hours because of setting on the previous day. The general operation means the haul of fishing gears conducted at intervals of one of or two hours after first operation. The bycatch in this study is defined as the other species except for anchovy, and bycatch rate refers to the proportion of bycatch to total catch. From the survey results, the average bycatch rates on first operations were 50% and 51% for Masa-ri and Supum-ri areas in Jindo, respectively. Also, the average bycatch rates on general operation were 2% and 3% for Masa-ri and Supum-ri areas in Jindo, respectively. The proportion of anchovy to total catch caught represented 75.5%. It needs the research on the selective fishing technology to reduce the bycatch on the gape net fishery.