• Fisheries and Aquatic Sciences
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• 제18권2호
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• pp.183-193
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• 2015

Several transgenic marine medaka Oryzias dancena strains harboring a green fluorescent protein (GFP) reporter construct regulated by an endogenous ${\beta}$-actin promoter were established and their expression characteristics in relation to transgene copy numbers were examined in 21 transgene genotypes. Most of the transgenic strains displayed transgene insertion patterns typical of microinjection-mediated introduction of foreign DNA into fish embryos, characterized by the random integration of multiple transgene copies (ranging from 1 - 282 copies per cell), often accompanied by the formation of concatemer(s), as assessed by genomic Southern blot hybridization analysis and qPCR. Transgenic strains showed ubiquitous and continued temporal and spatial expression patterns of the transgenic GFP during most of their life cycle, from the embryonic stage to adulthood, enabling assessment of the expression pattern of the endogenous ${\beta}$-actin gene. However, a comparative evaluation of transgene copy numbers and expression levels showed that copy number-dependent expression, the stability of the ubiquitous distribution and expression efficiency per transgene copy varied among the transgenic strains. Fluorescence expression levels were positively correlated with absolute transgene copy numbers, whereas the expression efficiency per transgene copy was inversely related to the number of transgene integrant copies. Data from this study will guide the selection of potentially desirable transgenic strains with ubiquitous expression of a fluorescent transgene, not only in this marine medaka species but also in other related model fish species.

• 수산경영론집
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• 제12권2호
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• pp.73-100
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• 1981

Fisheries resources, due to their intrinsic biological -density dependent, and socio- economic -common property nature, might yield the sustained benefits to the society involved, depending on the degree to which the social management scheme, pursuing the optimum yield from each of them, is framed. And besides, the success or failure of the management on them would, with no doubt, lead parallelly to the direction on scientific study of "Natural Resource Economics." Thus the objectives of the management, to ensue the best use of these society's resource, should underlie the technical, economic, ana social efficiency all together to meet the maximization of society's benefits from yields, taking account of managerial efficiency. And those multiple conflicts need communications between biologists, social scientists, and managers given tile mandate, tobe coordinated to arrive at a unique value weighed, through the well-ordered system approach and resulting timely decision-making which accommodates dynamical fisheries aspects and varying social purposes. purposes.

• 한국수산과학회지
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• 제53권1호
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• pp.1-8
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• 2020

The reproductive biology of largehead hairtail Trichiurus japonicus, from near Jeju Island, Korea was investigated based on 4,384 individuals collected by commercial vessel from November 2016 to October 2019. There were more female specimens than male specimens (2.64:1). T. japonicus preanal lengths (PL) ranged from 10.5 to 53.5 cm; the relationships between PL and body weight (BW) were BW=0.0103PL^3.1293 for females and BW=0.0106PL^3.1251 for males. Monthly changes in gonadosomatic index were analyzed to estimate spawning season. The spawning period ranged from June to November. The size-frequency distribution of eggs suggested that T. japonicus exhibits multiple-spawning during a spawning period. The minimum size of females at maturity was 18.2 cm, while the size at sexual maturity was 25.0 cm.

• Ocean and Polar Research
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• 제34권2호
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• pp.185-195
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• 2012

This paper focused on forecasting a short-term production of oysters, which have been farmed in Korea, with distinct periodicity of production by year, and different production level by month. To forecast a short-term oyster production, this paper uses monthly data (260 observations) from January 1990 to August 2011, and also adopts several econometrics methods, such as Multiple Regression Analysis Model (MRAM), Seasonal Autoregressive Integrated Moving Average (SARIMA) Model, and Vector Error Correction Model (VECM). As a result, first, the amount of short-term oyster production forecasted by the multiple regression analysis model was 1,337 ton with prediction error of 246 ton. Secondly, the amount of oyster production of the SARIMA I and II models was forecasted as 12,423 ton and 12,442 ton with prediction error of 11,404 ton and 11,423 ton, respectively. Thirdly, the amount of oyster production based on the VECM was estimated as 10,425 ton with prediction errors of 9,406 ton. In conclusion, based on Theil inequality coefficient criterion, short-term prediction of oyster by the VECM exhibited a better fit than ones by the SARIMA I and II models and Multiple Regression Analysis Model.

• 한국수산과학회지
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• 제56권2호
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• pp.259-264
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• 2023

Day-night vertical euphausiid distribution was investigated at three stations in the East Sea using a Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS). Three euphausiid species were recognized. Euphausia pacifica was more dominant than Thysanoessa longipes. Euphausiids were collected at Station 1 at night, Station 2 at sunset, and Station 3 during the daytime. At Station 1, calyptopis and furcilia stages were concentrated from the surface to 30 m and 20-40 m, respectively. Juveniles and E. pacifica were distributed in strata shallower than 30 m. At Station 2, calyptopis and furcilia stages were dominant in strata from the surface to 40 m. Juveniles were not recorded in strata at 30-100 m. However, E. pacifica occurred in these strata. At Station 3, calyptopis and furcilia stages occurred in the upper 40 m of strata. E. pacifica was distributed deeper than 100 m and rarely occurred above 100 m. The furcilia stages weakly migrated, whereas the calyptopis stages did not. Juveniles and E. pacifica showed a clear migration pattern. Vertical distribution of euphausiids in the northern East Sea varied by life stage and time of day.

• 한국수산과학회지
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• 제46권5호
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• pp.528-533
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• 2013

This study evaluated the impact of antimicrobial resistant bacteria produced by inland pollution sources on coastal areas, and investigates antimicrobial resistance profiles of bacteria isolated from marine filter feeders. A total of 107 shellfish (short-necked clams Ruditapes philippinarum, ark shells Scapharca broughtonii, and oysters Crassostrea gigas) were collected from the southern coast of Korea, from which 204 Escherichia coli strains were isolated. The antimicrobial susceptibility patterns of isolated strains were analyzed for 15 antimicrobial agents used in Korea for clinical or veterinary therapy. Antimicrobial resistance was present in 44.6% of E. coli isolates against at least one antimicrobial agent. The rate of antimicrobial resistance in the Narodo area was higher than isolates from the Gangjinman area and Kamak Bay. E. coli isolates had a higher rate of resistance against: tetracycline (29.9%), streptomycin (25.5%), and trimethoprim (14.2%). Of 204 isolates, 29 (14.2%) were resistant to multiple antimicrobial agents.

• 한국수산과학회지
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• 제52권6호
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• pp.605-616
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• 2019

This study evaluated the abundance and antimicrobial resistance of Escherichia coli in oysters Crassostrea gigas and major inland pollution sources sampled in 2014-2015 from Jaranman-Saryangdo on the southern coast of Korea. The ranges of the geometric mean of E. coli concentrations in oysters and major inland pollution sources were <20-29.8 MPN/100 g and 7.5-137.2 MPN/100 g, respectively. We isolated 247 strains of E. coli (28 from oysters and 247 from major inland pollution sources) and examined the antimicrobial resistance patterns of all isolates. Isolates from both sources were highly resistant to rifampin (99.5-100%) and cephalothin (70.8-78.6%). The resistance rate was higher in E. coli isolated from oysters those from inland pollution sources. Multiple resistance against at least four antimicrobials was observed in 85.7% and 21.0% of the oyster and major inland pollution sources isolates, respectively.

• 해양환경안전학회지
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• 제16권3호
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• pp.249-258
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• 2010

1961년부터 2010년 현재까지 현행 국가정선해양관측이 고전적 방법에 의해 수행됨으로써 자동화된 시스템의 형태로 실시간 혹은 준실시간으로 자료를 제공하지 못하게 되는 부분에 대한 개선방향을 살펴보고, 우리나라 운용해양시스템의 실용화를 위하여 국가정선해양관측이 나아가야 할 방향을 제시하였다. 선상에서 관측이 끝난 이후부터 데이터베이스에 자료가 저장되는 시점까지 행해지는 수동화된 작업을 대체하기 위해서는, 수온, 염분뿐만 아니라 다양한 자동측정센서가 부착된 CTD(Conductivity-Temperature-Depth)에 연동된 컴퓨터에서 해양관측자료를 처리하고 실시간으로 품질관리를 수행하며 통신수단에 맞게 자료를 전송할 수 있도록 하는 자동화 소프트웨어의 개발이 필요하다. 관측자료를 실시간의 형태로 전송하기 위해서는 Inmarsat 위성통신장비를 활용한 전송시스템이 타당하고, 준실시간 형태의 전송으로는 CDMA(Code Division Multiple Access) 무선통신방식을 사용하여 연안역에 도달했을 때 수집된 자료들을 묶어서 보내는 방식이 적합하다. 실시간 품질관리 과정을 포함시켜 관측시 발생할 수 있는 여러 가지 원인의 오류를 미연에 방지할 수 있을 것이다.

• 수산경영론집
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• 제46권2호
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• pp.93-110
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• 2015

This research examined the transformations of the fisheries relations between Japan and Russia since the establishment of the Exclusive Economic Zone (EEZ) system. The author reviewed the transformations with investigation on mutual fishing access to EEZ including salmon & trout catches. The Japan-Russia fisheries relations have evolved through multiple developmental stages, which include mutual fishing access to EEZ, the reductions of a fishing quota to balance catches of the nations, provision of financial and technical support, and a payment system of EEZ fishing access fee. The Japanese salmon industry also has done similar practices, continuing to catch salmon and trout in the Russian EEZ. Additionally, Japan and Russia have attempted to develop joint fisheries projects and to assure fishing operation safety around Kuril Islands. The case of Japan-Russia mutual fishing access shows that a country that has authority over crucial fisheries resources tends to establish specific conditions of mutual fishing access so that it maximizes its national interest. Thus, this case gives us implication what could be future directions of Korea-China-Japan multinational fishing access. The principle of same number of fishing vessels and quantities of catches has worked in existing mutual fishing access to EEZ among Korea, China, and Japan. However, it is expected that a nation that is endowed with abundant fisheries resources would limit counterpart's fishing access to its EEZ. Therefore, Korean fisheries administration should prepare for all possible situations like a dramatic cut in fishing quota and the termination of fishing access. International fisheries cooperation and payment of fishing access could be viable options for such a situation.

• 한국수산과학회지
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• 제49권2호
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• pp.116-123
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• 2016

This study investigated the prevalence of Vibrio parahaemolyticus in the oyster Crassostrea gigas, which is commonly consumed raw. The presence of virulence factors and the antimicrobial susceptibility of isolates were also investigated. The overall prevalence rate of V. parahaemolyticus in oysters was 37.5% (36/96) and the range of concentrations was 30-11,000 MPN/100 g. PCR-based assays indicated that 9.6% (11/115) of the isolates were positive for the thermostable direct hemolysin-related hemolysin gene (trh), while none of the isolates were positive for the thermostable direct hemolysin gene (tdh). The Multiple Antibiotics Resistance (MAR) index was measured for 16 common antimicrobial agents and 46.1% (53/115) of the isolates had a MAR index > 0.2. The MAR index ranged from 0.07 to 0.73. The highest MAR index was observed with strain s150608, isolated in June 2015, which exhibited resistance to 11 antimicrobial agents. Our results demonstrate that oysters are high-risk sources of V. parahaemolyticus, although no antimicrobial agent was being used to promote growth or to treat bacterial infections in the sampled oyster-growing areas.