• Fisheries and Aquatic Sciences
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• 제4권3호
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• pp.130-137
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• 2001

In the present study, the locomotor and feeding activities of single red sea bream, Pagrus major were simultaneously investigated to examine the existence of such dual behaviour. Seven red sea bream of 13cm body length on average were placed individually in 35L tanks equipped with an infrared sensor and a newly developed demand-feeding device. Fish were exposed to a light: dark 12: 12h cycle and constant darkness (DD) to study endogenous rhythmicity. Under LD 12: 12 h, the daily pattern of behaviour differed between individual fish; some red sea bream were diurnal and others were nocturnal. Futhermore, some of them displayed an extraordinary flexibility in phasing because they were dark active but light feeding, and vice versa. Under DD, red sea bream showed free-running rhythms for locomotor activity and feeding. These results indicate that the type of phasing of locomotor activity did not necessarily decide the feeding phase; much of this is explained by the fact that red sea bream were demand-fed. Flexibility in phasing and a certain degree of independence between locomotor and feeding activities could be seen as an adaptative response of the highly adaptable circadian rhythms of fish.

• 생명과학회지
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• 제25권4호
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• pp.450-455
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• 2015

본 연구에서는 국내에서 주로 소비되는 국내산 및 수입산 참돔의 일반성분과 중금속 함량을 비교 분석하였고 생리활성을 비교하기 위하여 참돔을 용매의 극성에 따라 추출하여 항산화 및 세포독성 효과에 대해 연구하였다. 수입산과 비교했을 때 국내산 참돔은 높은 함량의 수분과 낮은 함량의 조지방, 조단백질 및 회분을 나타내었다. 국내산 및 수입산 참돔의 중금속 함량을 비교한 결과 원산지에 따른 유의적 차이를 보였으며 국내산 참돔의 수은 함량은 0.08 mg/kg으로 수입산 참돔보다 높은 함량을 나타내었으나 납의 경우 원산지에 따른 유의적 차이는 보이지 않았다. 국내산 및 수입산 참돔의 A+M 및 MeOH 추출물을 인체 섬유육종세포(HT-1080)에 처리하였을 때, 세포 내 활성산소종 생성 저해효과를 살펴 본 실험 결과, 국내산 및 수입산 참돔 추출물들에 의한 활성산소종 생성 억제효과를 비교해 보면 수입산 참돔 추출물에 의한 저해효과가 높았으며 두 추출물들 중 MeOH 추출물에 의한 저해효과가 높았음을 알 수 있었다. 인체 암세포들(AGS 및 HT-29)들에 대한 세포독성 활성 결과에서 AGS 암세포의 경우 국내산 참돔 A+M 및 MeOH 추출물들에 의한 세포독성 효과가 수입산 참돔A+M 추출물들보다 높았다. HT-29 암세포에 대해서는 국내산 참돔A+M 추출물에 의한 세포독성 효과가 수입산 참돔 A+M 추출물에 의한 것보다 높았고 MeOH 추출물에 의한 세포독성 효과는 유사했다. 따라서 본 연구 결과를 기초자료로 하여 향후 참돔의 다양한 생리활성 규명이 필요하다고 사료된다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.445-449
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• 2005

Various methods to detect the phytoplankton/red tide blooms in the oceanic waters have been developed and tested on satellite ocean color imagery since the last two and half decades, but accurate detection of blooms with these methods remains challenging in optically complex turbid waters, mainly because of the eventual interference of absorbing and scattering properties of dissolved organic and particulate inorganic matters with these methods. The present study introduces a new method called Red tide Index (Rl), providing indices which behave as a good measure of detecting red tide algal blooms in high scattering and absorbing waters of the Korean South Sea and Yellow Sea. The effectiveness of this method in identifying and locating red tides is compared with the standard Ocean Chlorophyll 4 (OC4) bio-optical algorithm applied to SeaWiFS ocean imagery, acquired during two bloom episodes on 27 March 2002 and 28 September 2003. The result revealed that OC4 bio-optical algorithm falsely identifies red tide blooms in areas abundance in colored dissolved organic and particulate inorganic matter constituents associated with coastal areas, estuaries and river mouths, whereas red tide index provides improved capability of detecting, predicting and monitoring of these blooms in both clear and turbid waters.

• 대한원격탐사학회지
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• 제15권4호
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• pp.321-327
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• 1999

As an example of many possible applications of OSMI data, we present a method to detect red tides. In Korean waters, red tides usually occur in the South Sea where the turbidity is usually high due to strong tidal mixing in the shallow sea. The conventional case 1 chlorophyll algorithm cannot be applied since it cannot distinguish chlorophyll from SS (suspended sediments). In October 1998, a red tide outbreak occurred off the coast of KunSan. We analyzed the SeaWiFS data of the outbreak. The standard SeaWiFS chlorophyll algorithm OC-2 was poor in identifying the red tides. However, comparison of spectra of normalized water-leaving radiance indicates that red tide pixels can be distinguished from sediment-laden pixels. Channel 443 and 555 were effective in showing the spectral characteristics. We suggest K490 algorithm as an example in summarizing the information of the spectra and thereby in distinguishing the red tide pixels. Further development is desirable.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.381-385
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• 1999

As an example of many possible applications of OSMI data, we present a method to detect red tides. In Korean waters, red tides usually occur in the South Sea where the turbidity is usually high due to strong tidal mixing in the shallow sea. The conventional case 1 chlorophyll algorithm cannot be applied since it cannot distinguish chlorophyll from SS (suspended sediments). In October 1998, a red tide outbreak occurred off the coast of Kunsan. We analyzed the SeaWiFS data of the outbreak. The standard SeaWiFS chlorophyll algorithm OC2 was poor in identifying the red tides. However, comparison of spectra of normalized water-leaving radiance indicates that red tide pixels can be distinguished from sediment-laden pixels. Channel 443 and 555 were effective in showing the spectral characteristics. We suggest K490 algorithm as an example in summarizing the information of the spectra and thereby in distinguishing the red tide pixels. Further development is desirable.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.360-363
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• 2006

The red tide related with Cochlodinium Polykrikoides bloom has been frequently occurred around the South Sea of Korea and caused the economic loss in the coastal breeding grounds. The outbreak scale was usually change by physical, biological and environmental condition at each years. Relatively large-scale red tide occurred in 1995, 1997, 1999, 2001, 2002 and 2003 through spatial scale, duration and maximum density. Compared the scale of red tide with physical condition around the South Sea, the lower coastal temperature on August around the South Sea corresponded with the large scale red tide. By serial oceanographic investigations on August in the South Sea and estimated wide area temperature information by satellite, SSTA around the South Sea and wide area was negative when the outbreak of red tide was large scale. From the results of temperature difference between surface and 30m layers, the occurrence of enormous red tide has a tendency when the temperature gradient around the seasonal thermocline was weakened. Larger Kuroshio volume transport in the upstream was also corresponded with the large scale red tide.

• 한국환경과학회지
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• 제9권3호
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• pp.215-221
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• 2000

The relationship between the distribution of sea surface temperature(SST) and dinoflagellate(Cochlodinium polykrikoides) bloom areas were studied. The SST data were derived from the infrared channels of AVHRR(Advanced Very High Resolution Radiometer) sensor on NOAA(National Oceanic and Atmospheric Administration) 12 and 14 satellites during 1995-1998. The initial water temperature at C. polykrikoides bloom was about 21${\circ}C$ at the coastal areas of the South Sea and along the shore of the East Sea of Korea during the summer season of 1995. The northern limit of red tides was coincident with that of 21${\circ}C$ isothermal line in the East Sea. The red tides that initially bloomed at the coast of Pohang on September 21, 1995 moved to the coast of Uljin on September 26, 1995. The skipped appearance of the red tides in the areas between Pohang and Uljin was due to the East Korean Warm Current, which was moving offshore from Pohang to approach to Uljin. The cold water which was formed by tidal front in the western coast of the South Sea and by upwelling water from deep layer in the southeastern coast of the Korean peninsula played a role in blocking the spreading of red tides during summer season in 1997 and 1998. In conclusion, the distribution of red tides appeared to be dependent on the initial water temperature at red tides bloom. The SST at the red tides varied from 21${\circ}C$ to 25${\circ}C$; 21${\circ}C$, 23${\circ}C$, 24 and 24-25${\circ}C$ in 1995, 1996, 1997 and 1998, respectively.

• Fisheries and Aquatic Sciences
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• 제4권3호
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• pp.138-143
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• 2001

Red sea bream, Pagrus major a fish species characterized by its dualistic feeding pattern, was investigated to study the synchronizing effect of light and food on the demand-feeding rhythm. Nocturnal and diurnal red sea bream, both in groups and individually, were exposed to restricted-feeding and Light-Dark cycles of different periods. The phase relationship between both zeitgebers was also studied. In some cases, food availability restricted to the light or dark phase contrary to that of the previous feeding phase changed a diurnal feeding pattern into nocturnal and vice versa, suggesting that food can be one of the switching factors that decides whether the circadian system of red sea bream is diurnal or nocturnal. However, the fact that the feeding pattern of some fish was unrelated with the phase in which food was available suggests that other internal and/or external-factors could be involved in the temporal flexibility of red sea bream.

• 한국식품조리과학회지
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• 제15권6호
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• pp.639-644
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• 1999

The objective of this study was to compare the quality characteristics of cultured and red sea bream. The color of dorsal muscle was different between wild and cultured red sea bream. Lipid content of the dorsal muscle was higher in cultured fish than in wild one. The contents of moisture and crude protein in cultured fish muscle were almost same as those of wild one. Sensory evaluation of raw fish meat showed that cultured fish had lower preference in appearance, taste and texture than wild one. Especially the texture of cultured raw fish meat had lower preference than wild meat. For cooked fish meat, cultured fish were harder and less juicy than wild fish. These textural differences between wild and cultured meats were confirmed by objective evaluation including the measurements of hardness, springiness, and cohesiveness. Light microscopic observation showed that cultured red sea bream had more lipid in the surface layer near epidermis than wild one. Also more lipid droplet between muscle fibers were observed in cultured red sea bream by SEM.

• 대한공간정보학회지
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• 제23권1호
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• pp.65-71
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• 2015

여름철이 되면 매년 남해안에서 발생되고 있는 적조현상은 양식장을 운영하는 어민들에 막대한 피해를 주고 있으며 이를 방재하기 위한 노력이 다각도로 진행되고 있다. 특히 위성영상을 이용한 적조 모니터링은 발생해역 전반에 걸친 적조발생자료를 취득할 수 있어서 방재 계획수립에 중요한 정보를 제공하여 줄 수 있다. 따라서 본 연구에서는 천리안 GOCI영상을 이용하여 하루 중 적조의 확산과 감소를 모니터링할 수 있는 결과를 제시하기 위하여 경상남도 남해안 지역을 선정하고 2013년(8월 12일), 2014년(9월 11일) GOCI영상자료를 분석한 결과 다음과 같은 결론을 얻었다. 남해안 해역의 적조발생 패턴은 오전에 거제도 남부해역에서 출현하여 점점 더 확산되다가 오후 1시에 최대가 되고 그 후 서서히 감소되는 경향을 보여주었다. 또한 하루 중 적조의 중심 이동은 거제시 남부해역에서 적조가 시작하여 서쪽으로 이동하다가 정오를 기하여 다시 동쪽으로 이동하는 경향을 보여주었다. 향후 적조 생물의 특성과 해수유동, 태양 일조량, 그리고 해수온도 등 많은 요인에 대한 추가적인 연구가 필요하다고 판단되지만, GOCI 영상을 이용한 적조이동 모니터링은 적조의 확산과 이동을 예측하여 방재하고 관리하는데 매우 중요한 정보가 될 것으로 생각된다.