• Title/Summary/Keyword: National Tide

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Catch fluctuation of the Pound Set Net According to Tide Age in the Coastal Waters of Jeju (제주 연안의 소대망에서 조석에 의한 어획량 변동)

  • Kim, Byung-Yeob;Seo, Du-Ok;Lee, Chang-Heon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.42 no.1
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    • pp.83-88
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    • 2009
  • The purpose of this paper is to obtain the fundamental data on the catch fluctuation in the pound set net according to the tide age from the catch recorded from the year 1997 to 2004 in the coastal waters of Guideok, Jeju. Total catch by the pound set net had a little connection with the tide age. During increasing tide, total catch were reduced slightly from the neap tide to the high tide while there seemed to be a little sign of rise in the total catch until decreasing tide. But in the relation between the catches and the tide age, the level of the correlation coefficient chosen at $p{\le}0.05$ was not significant. Therefore, the catch of the pound set net seemed not to be influenced by the tide age. In addition, CPUE at the high tide was higher than that at the neap tide. When the catch per operating frequency was graded in the order under 50 kg, 50-100 kg and 100-200 kg, the frequency rate by the pound set net was 38%, 19% and 19%, respectively.

Statistical analyses on the relationships between red tide formation and meteorological factors in the Korean Coastal Waters and Satellite monitoring for red tide (한국 연안의 적조형성과 기상용인간의 상관성에 대한 통계학적 해석 및 위성에 의한 적조모니터링)

  • Yoon Hong-Joo;Lee Moon-Ok;Ryu Cheong-Ro
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.279-284
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    • 2004
  • Red tide(harmful algae) in the Korean Coastal Waters has a given a great damage to the fishery every year. However, the aim of our study understands the influence of meteorological factors (air and water tempaerature, precipitation, sunshine, solar radiation, winds) relating to the mechanism of red tide occurrence and monitors red tide by satellite remote sensing, and analyzes the potential area for red tide occurrence by GIS. The meteorological factors have directly influenced on red tide formation. Thus, We want to predict and apply to red tide formation from statistical analyses on the relationships between red tide formation and meteorological factors. In future, it should be realized the near real time monitoring for red tide by the development of remote sensing technique and the construction of integrated model by the red tide information management system (the data base of red tide - meteorological informations).

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Interactions between marine bacteria and red tide organisms in Korean waters

  • Seong, Kyeong Ah;Jeong, Hae Jin
    • ALGAE
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    • v.28 no.4
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    • pp.297-305
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    • 2013
  • There is increasing interest in the relationships between marine bacteria and red tide organisms. Some bacteria are known to kill red tide organisms, and may be responsible for accelerating the termination of red tides. Thus, certain algicidal bacteria have been proposed for the control of red tides. Meanwhile, many red tide organisms are known to feed on marine bacteria. The roles of marine bacteria and red tide organisms are therefore reversible. In Korean waters, the killing of red tide organisms by algicidal bacteria, and also the feeding of red tide organisms on marine bacteria have been extensively investigated. The findings of such studies may influence the conventional view of red tide dynamics, and also planktonic food webs. Here, we review the species and concentrations of algicidal bacteria that kill red tide organisms in Korean waters, as well as the ingestion rate and grazing impact of red tide organisms on marine bacteria. Furthermore, we offer an insight into the ecological roles of these 2 components in marine planktonic food webs.

Satellite Monitoring and Prediction for the Occurrence of the Red Tide in the Middle Coastal Area in the South Sea of Korea

  • Yoon, Hong-Joo;Kim, Young-Seup
    • Korean Journal of Remote Sensing
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    • v.19 no.1
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    • pp.21-30
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    • 2003
  • It was studied the relationship between the red tide occurrence and the meteorological and oceanographic factors, the choice of potential area for red tide occurrence, and the satellite monitoring for red tide. From 1990 through 2001, the red tide continuously appeared and the number of red tide occurrence increased every year. Then, the red tide bloomed during the periods of July and August. An important meteorological factor governing the mechanisms of the increasing in number of red tide occurrence was heavy precipitation. Oceanographic factors of favorable marine environmental conditions for the red tide formation included warm water temperature, low salinity, high suspended solid, low phosphorus, low nitrogen. A common condition for the red tide occurrence was heavy precipitation 2∼4 days earlier, and the favorable conditions for the red tide formation were high air temperature, proper sunshine and light winds for the day in red tide occurrence. From satellite images, it was possible to monitor the spatial distributions and concentrations of red tide. It was founded the potential areas for red tide occurrence in August 2000 by CIS conception: Yeosu∼Dolsan coast, Gamak bay, Namhae coast, Marado coast, Goheung coast, Deukryang bay, respectively.

A case study of red tide detection around Korean waters using satellite remote sensing

  • Suh, Y.S.;Lee, N.K.;Jang, L.H.;Kim, H.G.;Hwang, J.D.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.654-655
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    • 2003
  • Korea has experienced 10 a Cochlodinium polykrikoides red tide outbreaks during the last 10 years (1993-2002). The monitoring activities at National Fisheries Research and Development Institute (NFRDI) in Korea have been extended to all the coastal waters after the worst of fish killing by C. polykrikoides blooms in 1995. NFRDI is looking forward to finding out the feasibility of red tide detection around Korean waters using satellite remote sensing of NOAA/AVHRR, Orbview-2/SeaWiFS, IRS-P4/OCM and Terra/MODIS on real time base. In this study, we used several alternative methods including climatological analysis, spectral and optical methods which may offer a potential detection of the major species of red tide in Korean waters. The relationship between the distribution of SST and C. polykrikoides bloom areas was studied. In climatological analysis, NOAA, SeaWiFS, OCM satellite data in 20th and 26th August 2001 were chosen using the known C. polykrikoides red tide bloom area mapped by helicopter reconnaissance and ground observation. The 26th August, 2001 SeaWiFS chlorophyll a anomaly imageries against the imageries of non-occurring red tide for August 20, 2001 showed the areas C. polykrikoides occurred. The anomalies of chlorophyll a concentration from satellite data between before and after red tide outbreaks showed the similar distribution of C. polykrikoides red tide in 26th August, 2001. The distribution of the difference in SST between daytime and nighttime also showed the possibility of red tide detection. We used corrected vegetation index (CVI) to detect floating vegetation and submerged vegetation containing algal blooms. The simple result of optical absorption from C. polykrikoides showed that if we use the optical characteristics of each red tide we will be able to get the feasibility of the red tide detection.

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Meteorological characteristic and satellite monitoring for red tide in the Korean coasts

  • Yoon, Hong-Joo;Kim, Seung-Cheul
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.873-875
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    • 2003
  • It was studied the relationship between the red tide occurrence and the meteorological factors, and the satellite monitoring for red tide. From 1990 through 2001, the red tide continuously appeared and the number of red tide occurrence increased every year. A common condition for the red tide occurrence was heavy precipitation 2${\sim}$4 days earlier, and the favorable conditions for the red tide formation were high air temperature, proper sunshine and light winds for the day in red tide occurrence. From satellite images, it was possible to monitor the spatial distributions and concentrations of red tide.

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Red Tide Prediction in the Korean Coastal Areas by RS and GIS

  • Yoon, Hong-Joo
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.332-335
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    • 2006
  • Red tide(harmful algae) in the Korean Coastal Waters has a given a great damage to the fishery every year. However, the aim of our study understands the influence of meteorological factors (air and water temperature, precipitation, sunshine, solar radiation, winds) relating to the mechanism of red tide occurrence and monitors red tide by satellite remote sensing, and analyzes the potential area for red tide occurrence by GIS. The meteorological factors have directly influenced on red tide formation. Thus, We want to predict and apply to red tide formation from statistical analyses on the relationships between red tide formation and meteorological factors. In future, it should be realized the near real time monitoring for red tide by the development of remote sensing technique and the construction of integrated model by the red tide information management system (the data base of red tide - meteorological informations). Finally our purpose is support to the prediction information for the possible red tide occurrence by coastal meteorological information and contribute to reduce the red tide disaster by the prediction technique for red tide.

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Catch fluctuation of the rectangular set net according to the tide age in the coastal waters of Jeju (제주연안 각망의 조석에 의한 어획량 변동)

  • Lee, Chang-Heon;Choi, Chan-Moon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.44 no.2
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    • pp.112-119
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    • 2008
  • The fundamental data on the catch fluctuation in the rectangular set net according to the tide age were developed based on the catches recorded from the year 1986 to 2004 in the coastal waters of Hamdeok, Jeju. Total catch by the rectangular set net had a deep connection with the tide age. In particular, during increasing tide, total catch were reduced gradually from the neap tide to the high tide. As it turned out, the slope of total catch declined by degree and showed a correlation coefficient of determination of 0.76. On the contrary, in the case of decreasing tide, there was little sign of rise in total catch. In particular, large catch seemed to occur at the next tide to the neap tide. In the relation between the catch and the tide age, the level of the correlation coefficient chosen at $p{\leq}0.05$ decreased in the order rabbitfish(-0.84) and horse mackerel(-0.71), while the significance of other dominant species were not selected.

Tide-induced changes in marine fish cage-shape cause changes in swimming behavior of cultured chub mackerel (Scomber japonicus)

  • Hwang, Bo-Kyu;Lee, Jihoon;Shin, Hyeon-Ok
    • Fisheries and Aquatic Sciences
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    • v.23 no.4
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    • pp.14.1-14.14
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    • 2020
  • We performed field measurements of the behavioral changes in cultured chub mackerel (Scomber japonicus) caused by tide-induced changes in the shapes of their small-sized tetragonal fish cages. The field measurements were conducted in two separate periods: neap tide, a period in which the shape of the fish cages was stable; and spring tide, a period in which the fish cages are significantly deformed, which was expected to have significant influences on fish behavior. In the spring tide, the cages were deformed greatly by the moving water, with different water velocities affecting the cages to different degrees; the volume loss was estimated at 4.9% and 7.3% for v = 0.114 m/s and v = 0.221 m/s, respectively. The fish exhibited significantly different behaviors between the neap tide and spring tide. During the neap tide, the fish remained in the lower part of the cage, but during the spring tide they made frequent upward and downward movements, and their horizontal distribution changed significantly due to the changes in the shape of the cage. The cage deformation during the spring tide greatly influenced the swimming behavior of fish.

Statistical Analyses on the Relationships between Red Tide Formation and Meteorological Factors in the Korean Coasts, and Satellite Monitoring for Red Tide (한국 연안에서의 적조형성과 기상인자간의 상관성에 대한 통계학적 해석 및 위성에 의한 적조 모니터링)

  • Yoon, Hong-Joo;Kim, Hyung-Seok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.41 no.2
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    • pp.140-146
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    • 2005
  • The aim of our study understands the influence of meteorological factors relating to the formation of the red tide, and monitors the red tide by satellite remote sensing. The meteorological factors have directly influenced on red tide formation. Thus, it was possible to predict and apply to red tide formation from statistical analyses on the realtionships between red tide formation and meteorological factors, and also to realize the near real time monitoring for red tide by satellite remote sensing.