• 수산해양교육연구
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• 제27권6호
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• pp.1610-1618
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• 2015

This study is aimed to estimate price interactions between wild caught fish and farmed fish on the Korean seafood market, using multivariate cointegration analysis. Major commercially important four wild caught fish (chub mackerel, hairtail, yellow croaker and spanish mackerel) and two farmed fish(oliver flounder and black rockfish) are selected as analytical target fish species. Between 2000 and 2013, monthly production and price data are used in this study. The results of cointegration test showed that there would be a long-term equilibrium relationship among 4 wild caught fish and 2 farmed fish. However, the results of exclusion test indicated that farmed fish might not contribute significantly to the long-run relationship, suggesting that farmed fish might be only a weak substitute for wild caught fish, but no significant interaction could be found.

• Ocean and Polar Research
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• 제39권2호
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• pp.73-84
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• 2017

The probability distribution of ichthyoplankton is important for enhancing the precision of sampling while reducing unnecessary surveys. To estimate the ichthyoplankton detection proportion (IDP) and its margin of error (ME), the monitoring information of the chub mackerel's (Scomber japonicus) ichthyoplankton presence-absence sampling data has been were collected over approximately 30 years (from 1982 to 2011) in the Korean coastal seas. Based on the computed spatial distributions of the mackerel's IDP and ME, the confidence interval (CI) range, defined as 2 ME, decreases from approximately 80% to 40% as the sample size n increases from 4 to 24 and the ME is approximately 40% in the typical (seasonal survey) case n = 4 per year. The IDP and ME off Jeju Island are relatively high at the 0.5-degree smoothing level. After increasing the spatial smoothing level to 1.0-degree, the ME decreased, and the spatial distribution pattern also changed due to the over-smoothing effects. In this study, the 0.5-degree smoothing is more suitable for the distribution pattern than the 1.0-degree smoothing level. The area of the high IDP and the low ME on the mackerel's ichthyoplankton was similar to the estimated spawning ground in the Korean peninsula. This information could contribute to enhancing for the spawning ecology surveys.

• 한국양식학회지
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• 제21권4호
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• pp.234-238
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• 2008

고등어 Scomber japonicus의 종묘생산 및 양식가능성을 조사하기위하여 난발생에 따른 수온과 염분의 영향을 조사하였다. 수정란의 난경은 $0.91{\sim}1.33\;mm$였으며, 1개의 유구를 갖고 있는 구형의 분리부성란이었다. 수정에서 부화에 이르기까지 평균 소요시간은 $16^{\circ}C$일 때 약 70시간, $20^{\circ}C$일 때 48시간, $24^{\circ}C$일 때 42시간, $28^{\circ}C$일 때 34시간으로 고수온일수록 빠른 경향이었다. 부화율은 자연해수 조건인 $20{\sim}24^{\circ}C$와 $33{\sim}35\;psu$ 범위에서 가장 양호하였다. 난발생의 각 단계에 이르기까지 수온(T: $^{\circ}C$)에 따른 발생속도(t: hour)는 수온이 높을수록 빨랐으며, 난발생이 진행되지 않는 생물학적 영도는 평균 $6.9^{\circ}C$로 추정되었다.

• 한국어병학회지
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• 제17권1호
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• pp.1-10
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• 2004

해수 환경 중의 VHSV 분포 조사를 위하여, 2003년 2월에서 5월까지 동해 및 남해안 인근 해역에 서식하는 자연산 해수 어류를 채집하였다. 바이러스 분리용 시료는 9종의 해수 어류로서 42개의 시료를 분석하였다. 각 시료의 조직여과액을 Epithelioma papulosum cyprini (EPC) cells에 접종한 결과, 고등어 Scomber japonicus와 숭어 Mugil cephalus에서 바이러스가 분리되었으며 이들 바이러스는 RT-PCR법을 이용하여 VHSV로 동정할 수 있었다. 고등어에서 VHSV가 검출되었다는 기보고는 있지만, 숭어에 대해서는 본 연구에서 처음으로 VHSV를 분리하였다. 자연산 어류에서 유래된 세 개의 VHSV isolates에 대한 glycoprotein gene을 분석한 결과, 이들 바이러스는 양식 넙치에서 질병을 유발하는 VHSV isolates와 유사하며 모두 genogroup I (American type)에 속하는 것으로 밝혀졌다.

• 수산경영론집
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• 제45권2호
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• pp.61-72
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• 2014

This study aimed to empirically investigate the applicability of ecosystem-based TAC (Total Allowable Catch) fisheries management targeting the large purse seine fishery where multi-species are regulated by TAC. Using a linear programming, the optimal fishing effort and the catch amount by species which maximize fishing profits were analyzed under the constraint condition of catch limits by species. Analytical results showed that an application of TAC on only chub mackerel would have negative impacts on fish stocks such as hairtail and jack mackerel by increasing the level of fishing effort to achieve its allocated catch limit. However, under the constraint condition of catch limits of all species, it was shown that optimal catches of all species were achieved within their catch limits. It implies the importance of ecosystem-based management considering biological and technical interactions of species those were excluded in the traditional single species fisheries management.

• Journal of Ecology and Environment
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• 제35권1호
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• pp.15-25
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• 2012

Time series of ocean climate indices and catch records were used to identify the alternation patterns of pelagic fish populations in relation to climate regime shifts. During 1910-2008, an orderly alternation of dominant pelagic fish groups was observed in the Tsushima Warm Current (TWC; Yellow Sea-East China Sea-East Sea/Japan Sea) and Kuroshio-Oyashio Current (KOC; Northwestern Pacific) regions. After the collapse of herring fishery in the late 1920s, the sardine (A group) dominated in the 1930s, 3 other species (C group; Pacific saury, jack mackerel, and anchovy) dominated in the 1950s-1960s, chub mackerel (B group) dominated in the 1970s, and then sardine (A group) dominated again during cool regime in the 1980s. As sardine biomass decreased in association with the climate regime shift that occurred in the late 1980s, catches of C group immediately increased after the regime shift and remained at high levels during warm regime in the 1990s. Alternations of dominant fish groups occurred 6 times between 1910 and 2008. The dominant period of the 7 species lasted for 10-20 years. The catch of Pacific sardine in the TWC and KOC regions showed a negative correlation with the catch of the other 5 species (Pacific herring, anchovy, jack mackerel, Pacific saury, and common squid), suggesting that the abundance of the 5 species is strongly affected by the abundance of Pacific sardine in relation to the climate regime shifts. The total catch level of the 7 species in the KOC region was generally higher than that in the TWC region before 1991 but was lower after 1992, suggesting that the fish populations in the Pacific side are shifted to the TWC region by zonal oscillation of the oceanic conditions in relation to the climate regime shift in the late 1980s.

• 한국수산과학회지
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• 제43권6호
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• pp.581-588
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• 2010

To examine the functional properties of conjugated linoleic acid (CLA) and ascidian tunic extracts in fish, we compared mackerel fed ascidian tunic extract and CLA (CA25) and a control group. The daily growth index of CA25 was 1.92 compared to 1.86 in the control group. The viscerosomatic index of CA25 was 36.7% lower than that of the control group. After 8 weeks, the protein content decreased from 19.7 to 17.5% in the CA25 group. The ascidian tunic extract content in the viscera was much higher than in muscle (0.13 vs. 0.03 mg/100 g) after 8 weeks. At the start, the n-3 fatty acid content of the experimental fish was 25.2% in muscle and 23.7% in viscera. The CLA content in muscle in the CA25 group was 2.1% after 4 weeks and 2.3% after 8 weeks. By contrast, the CLA content in viscera did not change after 8 weeks.

• 한국발생생물학회지:발생과생식
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• 제12권3호
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• pp.207-213
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• 2008

고등어를 습식법으로 인공 수정한 난을 대상으로 난발생 및 자치어 발육과정을 관찰하였다. 수정란의 형태는 구형의 분리부성란으로 유구는 1개를 가지고 있었으며, 난경은 $0.94{\sim}1.02\;mm$(평균 $0.95{\pm}0.03\;mm$)였다. 부화에 소요된 시간은 수온 $20{\pm}0.5^{\circ}C$에서 51시간이 소요되었다. 부화 직후 자어의 전장은 $2.52{\sim}3.0\;mm$(평균 $2.75{\pm}0.04\;mm$)로 난황을 달고 있었고, 입과 항문은 아직 열려 있지 않았으며, 근절은 $28{\sim}31$개였고, 눈에는 흑색소포 소포가 착색되어 있었다. 부화 후 2일째의 전기 자어는 $3.12{\sim}3.63\;mm$(평균 $3.39{\pm}0.05\;mm$)로 난황이 완전히 흡수되었다. 부화 18일째 후기 자어는 전장이 $8.45{\sim}12.32\;mm$(평균 $10.85{\pm}4.36\;mm$)로 꼬리말단이 굽어지기 시작하면서 가슴지느러미, 등지느러미, 꼬리지느러미의 줄기가 형성되었다. 부화 25일째에는 $44.12{\sim}58.72\;mm$(평균 $55.95{\pm}6.74\;mm$) 외부 형태가 성어와 같은 치어기에 도달하였다.

• 한국수산과학회지
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• 제52권6호
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• pp.666-684
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• 2019

The horizontal distributions of eggs and larvae of chub mackerel Scomber japonicus were extensively surveyed in the vicinity of Korean waters between 31°75'N and 36°50'N during May and June in 2016 and 2017 (total of four surveys). We used a coupled bio-physical model (DisMELS) that combines an individual-based model (IBM) incorporating vertical migration of larvae and temperature-dependent survival to understand transport processes in the early life stage. Using the distributions of eggs and larvae from surveys, the potential spawning grounds were estimated at the northwest and southeast of Jeju Island and the central East China Sea in May, and at the southwestern East Sea and southern West Sea in June by running the model backward in time. In forward experiments within 30 days from the backward results, most larvae were transported to both the Korean and Japanese sides of the East Sea through the Korea Strait. However, the larvae released in the central East China Sea were transported to the Japanese side only, while those released in the southern West Sea were retained within that region. The survival rates at 30 days after release based on the simulation incorporating temperature-dependent survival throughout May and June were 29.7% in 2016 and 28.8% in 2017.

• 한국수산과학회지
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• 제48권5호
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• pp.621-630
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• 2015

This study investigated the concentration of total mercury in 17 species of commonly consumed fishes and assessed the risk to human health from provisional tolerable weekly intakes PTWI% as affected by migratory characterization, such as migration and vagility. The measured mean concentrations of total mercury in these 17 species of commonly consumed fishes suggest that mean concentrations of total mercury in 10 species of migratory fishes (largehead hairtail, chub mackerel, Pacific saury, skipjack tuna, Pacific cod, anchovy, Alaska pollack, brown croaker, Japanese Spanish mackerel, yellow croaker and Pacific herring) were low compared to those in 7 species of demersal fishes (red stingray, brown sole, bastard halibut, conger eel, blackmouth angler, rockfish and filefish). Based on the mean concentrations, the PTWI% of total mercury among commonly consumed migratory fishes was 3.393%, which was higher than that of commonly consumed demersal fishes (2.710%).