• Title/Summary/Keyword: 남해 연안

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Studies on the Forming Mechanism of The Fishing Ground of Yellow tail, seriola quinqueradiata, in The Adjacent Sea of Jeju Island (제주도 주변해역의 방어어장형성기구에 관한 연구)

  • 김준택;노홍길;김상현
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.38 no.1
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    • pp.20-35
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    • 2002
  • We studied the fishing ground of a yellowtail and oceanographic conditions around Chujado and Marado around Jeju Island from autumn to winter. Also we investigate the forming mechanism of fishing ground around Marado, which shows the best catch of yellowtail near Jeju island. The obtained results are summarized as follow ; 1. When the high temperature water about 15.0∼19.0 in depth of 50m distributed around Chujado and Marado, the fishing ground of Yellowtail is shows a good catch. On the contrary, when the low temperature water about 11.0∼14.0 is shows a poor catch. 2. Fishing grounds of yellowtail by handline fishing are formed with a school of Yellowtail migrating southward from the coastal sea of Korea and slaying around Marado to winter and spawn due to following factors. Firstly, a front of temperature and salinity is formed between inshore water and oceanic water around Marado. Secondly, small-size eddies and excellent horizontal and vortical mix which is created by strong tide and geographical features including irregular underwater ground and an isolated island. An abundant school of yellow tails stays in front of the tide where a good fishing ground was made.

Spatial distribution of Acartia(Copepoda, Calanoida) species in the southern coastal waters of Korea during summer (하계 남해연안에 출현하는 Acartia속 요각류의 공간 분포)

  • Choi, Seo Yeol;Seo, Min Ho;Shin, Kyoungsoon;Jang, Min-Chul;Soh, Ho Young
    • Korean Journal of Environmental Biology
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    • v.37 no.3
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    • pp.299-308
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    • 2019
  • The occurrence patterns of Acartia(Copepoda; Calanoida) species, A. erythraea, A. hongi, A. hudsonica, A. ohtsukai, and A. sinjiensis, were examined in the southern coastal waters of Korea in the summer in August 2012. The Acartia species had different spatial distribution according to environmental factors. A. erythraea showed higher density in a semi-closed bay (Gamak, Masan) where the dissolved oxygen was low (<2 mg L-1). A. sinjiensis showed a high density in a semi-closed bay when the chlorophyll-a concentration was >2 ㎍ L-1. A. ohtsukai showed a high density at water temperatures >26℃ and low salinity <30. A. hongi and A. hudsonica showed at water temperatures <27℃ and high dissolved oxygen (>5 mg L-1). These results suggest that environmental factors (temperature, salinity, dissolved oxygen, and chlorophyll-a concentration) may affect the spatial distribution of Acartia species dominant in the southern coasts of Korea in summer.

Understanding the Flow Properties by a Numerical Modeling in the South Sea of Korea (수치모델을 이용한 한국 남해의 유동특성 이해)

  • Bae, Sang-Wan;Kim, Dong-Sun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.4
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    • pp.295-307
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    • 2012
  • In order to understand the flow properties of the South Sea of Korea, tidal currents, wind-driven currents, density-driven currents and residual flows were investigated by using 3-dimensional numerical model(POM). In offshore regions, tide-induced residual current tends to flow eastward during the spring tide and westward during the neap tide. Total residual flow is irregular due to the bottom topography in the coastal area. The density-driven currents in the coastal area showed to be relatively weak, with little seasonal differences. The special tendency was apparent in the open sea. That is, the flow in the offshore regions showed results similar to that of the Tsushima current. The wind-driven currents in the coastal area showed to be much stronger than in offshore regions. Vertically, the flow of the surface layer was much stronger than that of the bottom layer. Through these results, material transport and diffusion in the south coast, as a basis for predicting the spread of use is expected to be available.

Seasonal Variations in Species Composition of Fishes Collected by an Otter Trawl in the Coastal Water off Namhae Island (저인망에 채집된 남해도 연안해역 어류의 종조성 및 계절 변동)

  • Huh, Sung-Hoi;Kwak, Seok-Nam
    • Korean Journal of Ichthyology
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    • v.10 no.1
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    • pp.11-23
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    • 1998
  • A total of 64 fish species was collected by an otter trawl in the coastal water off Namhae Island from May 1989 to April 1990. The dominant species were Acentrogobius pflaumii, Chaeturichthys hexanema, Chaeturichthys sciistius, Thryssa kammalensis, and Repomucenus valenciennei which accounted for approximately 66.5% of the total numbers and 34.5% of biomass of fish collected. Fish collected in the study area were primarily small fish species or early juverniles of large fish species. Only about 15%, exceeded 10cm in standard length. Seasonal variations in both species composition and abundance of fishes were major characteristics in the study area. The peak abundance occurred in April and September, while the number of species was relatively high from October to January. However, both the number of species and abundance of fishes showed the lowest values in winter.

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Seasonal Variation of Zooplankton Communities in the Southern Coastal Waters of Korea (남해 연안 동물플랑크톤 군집의 계절변동)

  • Moon, Seong-Yong;Oh, Hyun-Ju;Soh, Ho-Young
    • Ocean and Polar Research
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    • v.32 no.4
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    • pp.411-426
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    • 2010
  • The seasonal variations in the zooplankton community of the southern coastal waters of Korea were investigated seasonally in May, August, November 2005, and February 2006. A total of 74 taxa were sampled, with an average abundance ranging from 2,426~23,793 indiv./$m^3$, among which Noctiluca scintillans predominated. Noctiluca scintillans, Acartia omorii, Acartia erythraea, Paracalanus parvus s. l., Centropages abdominalis, Tortanus forcipatus, and Pseudevadne tergestina were the most abundant species detected. Zooplankton diversity was high around the inner regions during the summer, but it was relatively low in the stations located in the outer regions in the autumn. Non-metric multidimensional scaling (nMDS) revealed significant differences in the structures of the zooplankton community among the three regions. Our results showed that the seasonal variations in zooplankton communities in the southern coastal waters of Korea were attributable to seasonal changes in temperature, salinity, chlorophyll a concentrations, and N. scintillans blooms; additionally, this particularly study area might have been specifically influenced by the appearance of the Tsushima Warm Current.

Seasonal Variation in Species Composition and Abundance of Fish Assemblage in the Coastal Water off Namhae Island (남해도 연안해역에서 서식하는 어류군집의 종조성 및 계절변동)

  • Kwak, Seok Nam;Huh, Sung-Hoi;Kim, Ha Won
    • Korean Journal of Ichthyology
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    • v.20 no.4
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    • pp.303-312
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    • 2008
  • Seasonal variation in species composition and abundance of fishes was determined using monthly samples collected by a fyke net in coastal waters off Namhae Island in 2006. The sampling gear, both-side fyke net, is a widely used commercial fishing gear in shallow waters of the region. A total of 89 fish species was collected, the dominant species were Konosirus punctatus, Mugil cephalus, Lateolabrax japonicus, Acanthopagrus schlegeli, Sebastes inermis, Nibea mitsukurii, Clupeapallasii, Pampus echinogaster, Sebastes schlegeli and Limanda yokohamae. They accounted for 61.1% of the total number of individuals and 80.3% of the biomass. The dominant species were primarily composed of small individuals or juveniles of large-sized fishes. Abundance in the number of individuals and biomass showed peaks in April, May and September, and was lowest in January. Temporal change in fish abundance was related to the temperature and related factors.

Geochemical Compositions of Coastal Sediments around Jeju Island, South Sea of Korea: Potential Provenance of Sediment (한국 남해 제주도 연안 퇴적물의 지화학적 특성: 퇴적물의 근원지)

  • Lim, Dong-Il
    • Journal of the Korean earth science society
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    • v.24 no.4
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    • pp.337-345
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    • 2003
  • Surficial sediments from the northern coastal area of Jeju Island, southeastern Yellow Sea (South Sea of Korea) were analyzed for grain-size texture, some geochemical characteristics and clay mineralogy in order to assess their provenance. Rare-earth element compositions and some geochemical discrimination diagrams, especially of Ti/Al, Nb/Al and Rb/Al ratios, were revealed to be useful indices for identifying the origin of sediments. These indices, together with clay mineral compositions, suggest that the coarse-grained sediments originate from the volcanic rocks of Jeju Island, whereas the fine-grained sediments are derived from Chinese rivers, especially the Changjiang River. The oceanic circulation pattern and the physical-chemical properties of seawater in the Yellow and East China seal support the possibility that the fine-pained Changjiang (Yangtze River) sediments can reach the coastal area of Jeju Island (southeastern Yellow Sea).