• 한국수산과학회지
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• 제53권2호
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• pp.181-190
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• 2020

This study was conducted to estimate the optimum dietary DHA oil level and replacement level of enzyme treated fish meal (EFM) with sardine fish meal for juvenile Atlantic bluefin tuna Thunnus thynnus. Four diets were used: 1) EFM75 in which 75% EFM and 4% DHA oil were applied, 2) EFM60, with 60% EFM and 15% sardine fish meal, 3) DHA2 with 2% of DHA oil, and 4) SL as a raw fish feed. In a feeding trial, juvenile bluefin tuna (body weight 30.1 g) were randomly stocked into four experimental tanks (69 tones) and fed the experimental diets for 13 days. Fish weight gain was higher in the EFM75 and SL groups than in the DHA2 and EFM60 groups. The feed conversion ratio was lower in the EFM75 and DHA2 groups than in the EFM60 and SL groups. Survival was higher in fish fed the formulated diet groups (EFM75, EFM60 and DHA2) than in fish fed SL. This study clearly indicates that up to 10% dietary sardine fish meal can be used in juvenile T. thynnus diets, with an optimum dietary DHA oil level of approximately 3%.

• Fisheries and Aquatic Sciences
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• 제5권3호
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• pp.206-211
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• 2002

The aim of this study was to obtain the basic data on the fish school behavior change to approaching vessel and fish species identification by means of their swimming speed. The surveys were carried out for the juvenile southern blue fin tuna and other fish schools off Esperance, western Australia from January to March 1999. We observed changes of fish school behavior in response to the approaching vessel using 360-degree scanning sonar. The results showed that, a horizontal direction index used to quantify a change of fish school behavior did not identify dependence of a radial distance and a swimming speed. A Mann­Whitney test conducted using the horizontal swimming speed of both species identified by sonar specialists, did not reveal a significant difference.

• 수산해양기술연구
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• 제47권3호
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• pp.214-221
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• 2011

This study was performed to develop a video based system which can be used to measure the averaged fish size in a non-intrusive fashion. The design was based on principles of simple stereo geometry, incorporated fish dimensions weight relationships and took into consideration fish movement to lower system costs. As the fish size is an important factor that impacts the economy of an aquaculture enterprise. Size measurements, including fork length, width or height, girth, thickness and mass, can be used to determine fish condition in the fish farm, so the averaged fish size of fish cage needs to consistently monitor in open ocean aquaculture cage. A precision of ${\pm}3%$ for replicate length measurements of a 60cm bar is obtained at distances between 2.0 and 6.0m, and the mean fork length and mean swimming speed of bluefin tuna were estimated to 48.8cm and 0.78FL/s, respectively.

• 해양환경안전학회지
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• 제16권4호
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• pp.381-386
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• 2010

본 연구에서는 경남 통영 욕지도에 참치양식용 내파성 가두리 설치시 Cochlodinium polykridoides 적조 발생에 대한 적정 침강 깊이를 설정하기 위하여 장시간 동안 C. polykrikoides의 수직이동 현상을 조사하였다. 욕지도 근해의 식물플랑크톤 총 세포밀도는 월별에 따라 매우 큰 변동폭을 보이고 있으며, 대부분 규조류가 우점종으로 출현하고 있다. 여름철 와편모조류의 종 조성을 보면 Gymnodinium sp.가 총 19회로 가장 많은 출현 횟수를 보였고, 특히 C. polykrikoides도 총 8회로 나타났다. 또한 Karenia brevis 및 Fibrocapsa japonica와 같은 유독성 적조생물도 출현하여 이 지역에서 식물플랑크톤에 대한 장기적 모니터링이 필요할 것이다. 일출과 일몰에 따른 Chl-a 농도의 변화와 총 세포수의 변화는 상호 유의한 상관성을 나타내어 부침식 가두리 양식장은 표층으로부터 최소한 3m 침강시켜야 C. polykrikoides 적조로 인한 피해를 현저히 감소시킬 수 있을 것이다.

• 수산해양기술연구
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• 제59권2호
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• pp.125-134
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• 2023

The swimming behavior of pacific bluefin tuna (Thunnus orientalis) in the offshore sea cage of the brass fishing net was observed and analyzed by imaging sonar techniques. The cultured fish spent most of the time swimming a circular path along the circular cage wall and continued to swim only clockwise direction without completely changing the swimming direction during the 23-hour observation time. In addition, changed swimming behaviors were divided into four categories: (a) the behavior of a large group temporarily swimming in the opposite (counter clockwise) direction, (b) the behavior of a small group temporarily swimming in a small circular path, (c) the behavior swimming small circular path in the center of the cage, and (d) the behavior of a large group swimming across the center of the cage. The maximum swimming speed of the cultured fish was from 3.5 to 3.8 TL/s, the mode was from 1.2 to 1.4 TL/s and the swimming speed during the day time was faster than at night time. It was confirmed the cultured fish swam not only on the surface but also near the bottom net of the cage during the day, but swam mainly at the upper part of the cage at night.

• 한국수산과학회지
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• 제51권3호
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• pp.286-297
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• 2018

We analyzed scientific observer data to identify species composition and catch trends of Korean tuna longline fisheries in the Indian Ocean. The data were collected by Korean scientific observers onboard Korean tuna longline fishing vessels in the Indian Ocean from 2010 to 2015. The observers identified 94 species including 5 tuna, 6 billfish, 11 shark, 7 other fish, 5 seabird and 1 sea turtle. Albacore tuna Thunnus alalunga and southern bluefin tuna Thunnus maccoyii were the dominant tuna species, and swordfish Xiphias gladius were the most commonly captured billfish. During the survey periods, 87 seabirds were incidentally bycaught. Black-browed albatross Diomedea melanophris was the dominant seabird species in bycatch, especially in 2010. Cluster analysis showed difference in the species composition of catches between the eastern and western Indian Ocean.

• 한국식품영양과학회지
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• 제36권11호
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• pp.1417-1424
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• 2007

수산물 가공 중 부산물로 다량 발생하고 있는 7종의 fish frame(연어 frame, 삼치 frame, 붕장어 frame, 가다랑어 frame, 황다랑어 frame, 참다랑어 frame및 붉은메기 frame)의 생선 곰탕의 추출 소재로서 가능성을 검토하였다. 휘발성 염기질소와 중금속 함량의 분석 결과 참다랑어 frame과 연어 frame은 식품가공소재로 안전한 범위이었다. Fish frame 추출물의 수분을 제외한 주성분은 조단백질이었다. 7종 fish frame 추출물의 엑스분 질소와 비린내 및 맛에 대한 관능검사 결과 생선 곰탕의 제조를 위한 엑스분 추출소재로는 연어 frame이 가장 적절하였다. 연어 frame 추출물의 인 및 칼슘함량은 18.0 mg/100 mL 및 33.1 mg/100 mL이었다.

• 한국해안·해양공학회논문집
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• 제33권5호
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• pp.179-186
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• 2021

재생에너지 3020 이행계획, 한국판 뉴딜 계획 등에 따라 신재생에너지 생산 비중 증가 대응과 해상풍력발전 12GW 건설을 위해 어업생활권 점유 대안 마련과 주민 수용성 제고를 위한 방안이 요구된다. 본 연구는 동해에 적합한 해상풍력발전단지와 연계한 수산자원 공존모델의 차별방안을 제시하였다. 동해는 부유식 해상풍력 발전단지 조성의 최적지로 단지 내 공유수면을 활용하여 외해양식에 적합한 고부가가치 어종인 참다랑어를 양식함으로써 에너지 생산, 수산자원 개발, 관광산업화를 통한 이익 창출로 경제적 효과 발생을 예측하였다. 또한, 운영관리 기술 공유 등으로 예산 감축, 스마트 관리 추진과 어민소득 증대 가능성을 확인하였다.

• 한국양식학회지
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• 제21권4호
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• pp.272-277
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• 2008

참다랑어 Thunnus orientalis의 종묘생산기술개발을 위해 대량 종묘 생산과정에서의 성장과 생존, 사육수조와 배합사료의 단백질원의 차이에 따른 성장효과 대하여 조사하였다. 종묘생산 실험 결과 부화 후 30일째의 생존율은 0.69%, 전장과 평균체중은 각각 $49.83{\pm}2.52\;mm$, $1.03{\pm}0.09\;g$이었다. 사육수조 형태 차이에 따른 사육실험 결과, 성장률, 사료효율, 생존율 등 사육성적의 실험구간의 유의차는 없었다. 참다랑어 치어의 배합사료 개발을 위한 적정 단백원 평가에서 BIO구가 실험 종료시의 평균 체중과 성장률에서 SL구와 유의차를 보이지 않았으며, 사료효율과 실험 종료시의 전어체 조지방 함량은 BIO구가 SL구보다 유의적으로 높았다(P<0.05). 본 연구결과 BIO-CP가 참다랑어 치어용 배합사료의 적정 단백원으로 평가되었다.

• 수산해양기술연구
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• 제45권1호
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• pp.22-33
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• 2009

Ecological risk assessment(ERA), developed in Australia, can be used to estimate the risk of target, bycatch and protected species from the effects of fishing using limited data for stock assessment. In this study, we employed the ERA approach to estimate risks to tunas, billfishes, sharks, sea turtles and other species by the Korean tuna longline fishery in the Western and Central Pacific Ocean using productivity and susceptibility analyses of the ERA based on low(<1.30), medium(1.30-1.84) and high risk(>1.84). Albacore, bigeye, yellowfin, skipjack and bluefin tunas were generally evaluated in the medium risk. The susceptibility of tuna species, however, had higher risks than the productivity. Billfishes were also at medium risk, while sharks were at high risk by the tuna longline fishery. The risk of productivity was generally high, because most sharks caught by the tuna longline fishery have high longevities, i.e., over 10 years, including ovoviviparous species. Susceptibility, which is related with the selection of fishing gear, was also high, because the longline fishery has no gear modifications to prevent bycatch of protected species. Not only target tuna species were influenced by the tuna longline fishery in the Western and Central Pacific Ocean, but also nontarget species, such as pomfret, mackerels rays, sea turtle were done. Ecosystem-based fishery assessment tools, such as productivity and susceptibility analysis(PSA), have the ability to provide broad scientific advice to the policy makers and stakeholders.