• Environmental Engineering Research
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• 제24권4호
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• pp.638-645
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• 2019

This research was an evaluation of the fish fauna and the habitat for Brachymystax lenok tsinlingensis (B. lenok tsinlingensis) for 11 stations at the Bonghwa-gun sanctuary. The predominant species in this research area was Zacco koreanus. B. lenok tsinlingensis, which has been designated as an endangered freshwater fish in Korea, was found in the Bonghwa sanctuary zone, except at stations 5 and 6. The B. lenok individuals were shorter in length than 400 mm. In total, 13 endemic species were found, including Coreoleuciscus splendidus and Iksookimia longicorpus. Specimens of Koreocobitis naktongensis, a first grade endangered species, were also collected. The benthic macroinvertebrates consisted of four divisions, four classes, seven orders, 30 families, 60 species, and 10,344 individuals and were distributed among the orders Ephemeroptera (55.9%), Diptera (18.2%), Trichoptera (12.4%), Plecoptera (2.1%), and Odonata (0.3%).

• 한국어병학회지
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• 제34권1호
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• pp.117-121
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• 2021

An ayu (Plecoglossus altivelis) farm in Korea recently experienced an epidemic of vertebral column deformities where about 90% of fry displayed a vertebral column that was grossly opaque along either the cranial part of the column or its entire length. Abnormal fish were lordotic, scoliotic and/or kyphotic about midway down the spine. Examination of serial sections of whole fish showed only histological lesions in the vertebral column and suggested some disturbance in the early development of the vertebral centrum. Such abnormalities included a frayed spinal or notochord sheaths with irregular thickening and compression, mal-absorbed notochord cells, thickening of around cell layer and hypercellularity on both facets of the notochord sheath. No parasites, fungi, or bacteria were detected. While this lesion has only been reported once in the past, this is the first report of histopathological findings.

• 수산해양기술연구
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• 제40권1호
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• pp.37-46
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• 2004

제주도 연안 정치망 조업 시스템 개량과 개발분야에서 연안해역에서 널리 사용되고 있는 각망어구의 구조개량을 위한 기초연구로서 현재 사용되고 있는 실물망을 1/20로 축소하여 개량된 입구 구조를 갖춘 모형 어구 8종류를 제작하고, 실험 수조에서 고등어 어군을 이용하여 모형 어구에 대한 어군의 입 ${\cdot}$ 출망 행동을 관찰 분석하였는데, 그 결과는 다음과 같다. 1. 원통그물내에서의 어군의 행동 패턴은 원형 모양으로 한쪽 원통그물내에 체류하는 행동과 긴 타원형 모양으로 좌 ${\cdot}$ 우 원통그물내를 왕복 유영하는 행동패턴으로 분류할 수 있었다. 2. 모형 어구 내에서의 고등어 어군의 평균 유영 속도는 원통 그물 중간 부분에서 24.9cm/sec, 오른쪽 원통그물내에서 12.6cm/sec, 입구에서 32.0cm/sec였다. 3. 어군의 입망율은 경과 시간 60초일 때 표준 모형 어구에서는 47%였고, 깔대기 그물이 길이가 35cm 의 모형 어구에서는 40%로 나타났는데, 양자의 차이는 7% 정도로 그다지 크지 않았다. 4. 어군의 출망율은 경과 시간 60초일 때 표준 모형 어구에서는 69%였고, 깔대기 그물의 길이가 35cm 의 모형 어구에서는 10%로 나타났는데, 양자의 차이는 59% 정도로 그 폭이 컸다. 5. 어군의 잔여율은 경과 시간 60초일 때 표준 모형 어구에서는 31%였고, 깔대기 그물의 길이가 35cm의 모형 어구에서는 90%로 나타났는데, 양자의 차이는 59% 정도였다.

• Ecology and Resilient Infrastructure
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• 제9권2호
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• pp.100-106
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• 2022

섬진강 수계 210개 지방하천을 대상으로 하천연장과 보 밀도 대비 어류 출현종 현황을 분석하였다. 하천연장에 따른 어류 출현종수는 비선형지수함수 (Nonlinear exponential relationship) 관계를 보였다. 모델에 따른 계수값 (b)은 0.03이며, 결정계수(R²)은 약 59.0%인 것으로 나타났다. 모델식에 따른 예측기대종수는 실제 출현종수와 차이를 보였으며, 대상하천 가운데 약 110개 하천 (약 52.4%)에서 실제 출현종수는 예측기대종수보다 낮게 나타났다. 한편 섬진강 수계 하천에서 나타난 평균 보 밀도는 약 2.7개/km였으며, 이는 타 수계 하천과 비교시 월등히 높은 수치였다. 보 밀도 지표 (Index of Weir's Density, IWD)에 따른 어류출현종수간의 2-DKS 분석 결과 어류 다양성에 영향을 주는 보 밀도 역치값 (Threshold value)은 약 2.5개/km인 것으로 나타났다 (D_max=0.048, p<0.05). 실제 보 밀도 지표가 역치값 이상인 경우 어류 출현종수 대비 기대 종수비율은 70% 미만으로 낮아졌다. 따라서, 향후 수생태계 연속성 확보를 위한 보 밀도는 역치값 이하로 관리하는 것이 필요하다.

• 수산해양교육연구
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• 제9권2호
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• pp.149-166
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• 1997

This thesis is studied by means of operation diary of the factory ship GAECHEOG in the Sea of Okhotsk and the Sea of Bering from Jul. 1993 to Dec. 1996, We summarize these results as follows : 1. The factory ship GAECHEOG equipped trawl winch able to haul raw fish 700M/T per day and cargo winch able to unload manufactured goods 900M/T. The crews consist of 290~330 persons. 2. Factory machineries equipped surimi making plant able to process about 150M/T per day and fish meal plant able to manufacture about 70M/T per day. 3. The fishing ground from June to Nov. was the western Bering sea lying in the eastern Kamchaka peninsula and from Dec. to May, the fishing period to gather roe of a Pollack, was the Sea of Ohotsk lying in the western Kamchaka peninsula. 4. The buying catch of fish per each voyage from Dec. to May, the fishing period gathering Pollack-roe, was about 17,000~33,000M/T and from Jul. to Oct., the fishing period gathering non Pollack-roe, was about 10,000~21,000 M/T. 5. Raw fish was the most about 33,000M/T of the 2nd voyage in 1994 and was the least about 8,300M/T of the 1st voyage in 1993. Other voyages were about 13,000~18,000M/T. 6. The Pollack buying from Jul. to Nov. in the Bering sea was 5~7 fishes for one row in pan and body length about 40~50cm, and from Dec. to May in the Sea of Ohotsk was 6~8 fishes for one row in pan and body length about 37~45cm. 7. Surimi production in the 2nd voyage in 1994 was the most about 7,300 M/T, in the 1st voyage in 1993 was the least 1,900M/T and in other voyages was about 2,500~3,800M/T. The extraction rate of surimi goods for raw fish was about 17.4~26.5%. 8. Fish meal production in the 2nd voyage in 1994 was the most about 2,300 M/T, in the 1st voyage in 1993 was the least about 780M/T and in other voyages was about 1,100~1,700M/T. The extraction rate of fish meal goods for raw fish was about 7.3~10.7%. 9. Pollack-roe production was very much from Jan. to Apr. and was about 380~700M/T per each voyage. The extraction rate of Pollack-roe for raw fish was about 1.2~4.9%.

• 한국수산과학회지
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• 제31권3호
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• pp.317-322
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• 1998

Generally, the conventional fish size grading methods just adopt the mechanical technique. So the grading methods have a problem such that the graded fish is easy to hurt on the skin and in the internal organs. In this paper, a fish size grading machine is developed using an image processing method. The grading method is based on the principal axis theorem. The length and projected area of a fish are obtained by getting the principal axis and the product of inertia moment on the captured image of a target fish. The developed machine uses an uncontact technique that the target fishes go through the front side of the CCD camera. So the above stated problem can be improved. The performance of this method is discussed with the experimental results.

• 한국농공학회논문집
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• 제52권3호
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• pp.1-7
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• 2010

The ichthyofauna and passing efficiency of fishways were surveyed in Geumgang estuary from May to October in 2009. The fishes collected were classified into 24 species, 23 genera belonging to 8 families. These 24 species consist of 17 freshwater fish species, 3 migration fish species and 4 peripheral freshwater fish species. Seasonal function of fishways showed the migration from May to June and returning to the reservoir of fishes be washed out to sea when sluice gate open by rainfall in July and August. Most of the fishes catched in fishways moved from middle tide to high tide except for July. Fishes ascended fishways between the middle ebb tide and the ebb tide only July, because small freshwater swim against the fishway for leaching the reservoir through the newly formed flow when the water level at the fishway kept dropping. Small fishes that body length less than 200 mm mainly used gabion type fishways and fishes over 200 mm utilized a cascade type fishways. Based on the total individuals collected, the efficiency of the fishway was 1 % for the anadromous fish and over 80 % for freshwater fish. Therefore, it is concluded that ecological function of the fishway in the Geumgang estuary dike be very important not only for fish migration but also freshwater fishes's returning.

• 한국어병학회지
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• 제23권1호
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• pp.113-118
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• 2010

The present work describes myxozoan parasite found in the skin of cultured snakehead, Channa argus fingerings (total length, 5.5~7.2 cm) from Busan, Korea. Nature spores and plasmodia were found in the skin mucus of infected fishes. In fresh state, the total length of the spore was $27.96{\pm}2.50{\mu}m$. The size of spore body was $14.16{\pm}1.78{\mu}m{\times}4.88{\pm}0.61{\mu}m$. The polar capsules were pyriform and the size was $5.57{\pm}0.66{\mu}m{\times}1.36{\pm}0.33{\mu}m$. This is the first report of Henneguya sp. from cultured fish species in Korea, and further studies are necessary for definitive identification.

• 한국수산과학회지
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• 제46권6호
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• pp.973-976
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• 2013

We observed the vertical distribution and feeding ecology of the Mirror dory, Zenopsis nebulosa, in the Southern Sea of Korea from 2009 to 2013 using an otter trawl. The total length of captured individuals ranged from 11 to 48 cm. Individuals captured at greater depths were significantly larger than those from shallower sites. Fish abundance was significantly related to depth and temperature. We found that 89% of the total catch was obtained at depths between 80 and 140 meters. Prey organisms, including fish, crustaceans, and cephalopods, were found in Z. nebulosa stomachs. Fishes were the main prey items for all size groups. Cephalopods were consumed by individuals > 25 cm in length. Our findings suggested that the vertical distribution of Z. nebulosa varied with depth and temperature, and that the fish are carnivores.

• 한국수산과학회지
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• 제51권2호
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• pp.163-169
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• 2018

This study examined the expression of heat shock protein 70 (Hsp70) in red seabream Pagrus major infected by the, acanthocephalan parasites Longicollum pagrosomi. We cloned the full-length Hsp70 cDNA from the liver of the red seabream. The full-length cDNA had a 1,950 bp open reading frame (ORF) that encoded a protein of 650 amino acids. The deduced amino acid sequence of Hsp70 contained all of the conserved Hsp70 family signature sequences and an adenosine triphosphate (ATP)/guanosine triphosphate (GTP) binding motif, including the EEVD (consensus sequence that terminates in Hsp70 family) consensus sequence. The expression of Hsp70 mRNA was upregulated int the fish head-kidney and liver, as determined by quantitative real-time PCR. We quantified the Hsp70 mRNA expression in normal red seabream and fish infected fish by L. pagrosomi. The expression of Hsp70 mRNA was significantly higher in the infected red seabream. These results suggest that Hsp70 play a role of protection against stress and inflammation caused by the parasite and may help maintain homeostasis.