• Title/Summary/Keyword: 남해도

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Composition and Catch Variation of Fisheries Resources by Set Net in the Mizo Fishing Ground off Namhae Island (남해도 미조 정치망 어장의 출현 종과 어획량 변동특성)

  • Cha, Byung Yul
    • Korean Journal of Ichthyology
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    • v.21 no.3
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    • pp.191-199
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    • 2009
  • Fisheries resources collected by set net in the Mizo fishing ground off Namhae Island were studied from March to December 2004 to determine species composition and catch variation. The water temperature of the fishing ground ranged $10.9{\sim}25.1^{\circ}C$ A total of 69,147.5 kg comprising 39 species was caught during the survey period. Most of the catch was fishes (33 species); others included cephalopods (5 species) and crustaceans (1 species). The dominant species were migratory, such as Trichiurus lepturus, Ammodytes personatus, Engraulis japonicus, and Scomberomorus niphonius, and accounted for 81.2% of the total catch. Sub-dominant species were Sardinops melanostictus, Acanthopagrus schlegeli, shrimps, and Todarodes pacificus, but they accounted for only 12.1% of the total. The catch by set net during the fishing period was much higher in spring and in autumn than in summer, relating to the recruitment of dominant species. Although the number of species had a tendency to decreased after summer, the catch in autumn was also higher than that in spring due to high temperatures (>$17^{\circ}C$ and seasonal variation of dominant species. The dominant species in spring were A. personatus and E. japonicus and in autumn were T. lepturus, S. niphonius, and E. japonicus.

Effects of Water Temperature Inversion on the Stratification Variation in October and December in the South Sea of Korea (한국 남해에서 10월과 12월의 수온역전현상이 성층변동에 미치는 영향)

  • Lee, Chung-Il;Koo, Do-Hyung
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.3
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    • pp.165-171
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    • 2009
  • In order to illustrate the effects of water temperature inversion on the stratification variation in the South Sea of Korea, water temperature, salinity, and density measured in October and December 1999 by National Fisheries Research and Development Institute were reviewed. In October and December of 1999, temperature inversion occurred mainly between 25m and 75m, and in particular in depth of water, in December temperature inversion layer also was formed in the surface layer. In case of October and December, the Tsushima Warm Current (TWC), warm and saline water, was one of motors, and in December, influence of surface cold water was added Although northerly wind prevails in October and December, in October, expanding of the South Korean Coastal Waters (SKCW) towards offshore is not clear, but in December when wind speed is relatively greater than that in October and strength of the TWC become weak, the SKCW spreads towards offshore through the upper layer. Stratification variation was higher along the area where temperature inversion occurred.

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Suspended Particulate Matter of the Surface Water in Relation to the Hydrography in the South Sea of Korea in Early Winter (한국 남해의 초겨울 해황과 관련한 표층 부유물질의 분포)

  • Choi Yong-Kyu
    • Journal of Environmental Science International
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    • v.14 no.11
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    • pp.1063-1069
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    • 2005
  • In order to investigate the distribution of suspended particulate matter of the surface water in the South Sea of Korea in early winter, the cruise results during 2 to 8 December 2004 were analyzed in relation to the hydrography. The front was formed along the line connecting between Tsushima and Cheju Islands, which divided the water into two water masses; the coastal water with for temperature and for salinity, and the Tsushima Warm Current Water with high temperature and high salinity. In the coastal water the suspended particulte matter was 5.0-6.5 mg/l, while in the oceanic water suspended particulate matter was 4.5-5.0 mg/l. The coastal water showed higher mixing effects, compared to the oceanic area where vertical stratification was clearly formed. These indicate that the distribution of suspended particulate matter was affected by the stratification or mixing of the water column. Also it is suggested that the mixing effects of sea surface cooling and rind play an important role on the distribution of suspended particulate matter in the South Sea of Korea in winter time.