• Title/Summary/Keyword: southwestern coast

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Monthly variations in macroalgal flora and community structure in Hampyong Bay, Southwestern Coast of Korea (한국 남서해안 함평만의 월별 해조상 및 군집구조 변화)

  • Oh, Byoung-Geon;Choi, Han Gil
    • Korean Journal of Environmental Biology
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    • v.39 no.1
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    • pp.81-87
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    • 2021
  • The monthly variability in marine algal flora and community structure was examined in the intertidal zones of Doripo, and the biomass of an edible alga, Ulva prolifera, at Gaip-ri of Hampyong Bay on the southwestern coast of Korea was investigated over one year from April 2008 to March 2009. A total of 22 seaweeds were identified including five green, four brown, and 13 red algae. Based on importance value, Ulva australis was dominant over the year and the subdominant species were Ulva linza and Caulacanthus ustulatus at the Doripo coast of Hampyong Bay. The vertical distribution in terms of importance values was in the order of Ulva linza - C. ustulatus - U. australis - Sargassum thunbergii from the upper to the lower intertidal zones. The biomass of U. prolifera ranged between 2.4-98.2 g dry wt. m-2, with a maximum in June and a minimal in November. In the field, U. prolifera biomass could be positively related to seawater temperature. However, further research on the association between biomass and other environmental factors such as nutrients and light intensity is required.

The Chlorophyll Concentration in the Southwestern East Sea Observed by Coastal Zone Color Scanner (CZCS)

  • Lee Dong-Kyu;Son Seung-Hyun
    • Fisheries and Aquatic Sciences
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    • v.3 no.1
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    • pp.8-13
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    • 2000
  • Monthly mean chlorophyll concentration in the East Sea was estimated from the ocean color observed by the Coastal Zone Color Scanner (CZCS) on Nimbus-7 satellite which had performed various remote sensing missions from 1979 to 1986. The areas of high chlorophyll concentration were found in the sea between Siberia coast and Sakhalin Island, in the Donghan Bay and in the Ulleung Basin. In the southwestern East Sea, especially in the area near Ulleung Island, the yearly maximum chlorophyll concentration occurred in December. The chlorophyll concentration in Ulleung Basin in December was about two times higher than during spring bloom in April. The early winter bloom occurred in the warm side of the front that was formed between warm water from the East China Sea and nutrition rich cold water from the northern East Sea.

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Mean Flow and Variability at the Upper Portion of the East Sea Proper Water in the southwestern East Sea with APEX Floats

  • Lee, Ho-Man;Kim, Tae-Hee;Kim, Ju-Ho;Youn, Yong-Hoon
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2003.11a
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    • pp.145-150
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    • 2003
  • 16 APEX floats, autonomous profiling floats deployed as part of the Array for Real-time Geostrophic Oceanography (ARGO) program, are used to understand the currents at 800 m underwater in the southwestern East Sea. The flow penetrates into the Ulleung basin (UB) through two paths: an extension of the southward flowing the North Korean Cold Water along the east coast of Korea and between Ulleung Island and Dok island. Flows at 800 m are observed range 0.2 to 4.29 cm/sec and the variability in the north in the DB is stronger than that in the south. The eddy kinetic energy is found a few $cm^{2}$ $S^{-2}$. In the UB, cyclonic flows from 0.3 - 1.6 cm/see are observed with the bottom topography.

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Sedimentary Facies and Geochemical Characteristics of Upper Intertidal Zone, Southwestern Coast, Korea (한반도 남서해안 상부조간대의 퇴적상 및 지구화학적 특성)

  • Kang, Suk-Bum;Koh, Young-Koo;Park, Bae-Young;Youn, Seok-Tai;Kim, Joo-Yong;Oh, Kang-Ho;Shin, Sang-Eun
    • Journal of the Korean earth science society
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    • v.23 no.8
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    • pp.722-735
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    • 2002
  • In order to reveal sedimentary facies and geochemical characteristics on sediments distributed in upper intertidal zone, the southwestern coast of Korea, grain size and metal content analyses to the sediments were carried out. The grain size distribution of sediments shows very wide range from gravel to mud. The sediments are very well sorted to very poorly sorted and mostly positively skewed. Geochemical behavior of metals in the sediments is dependant on grain size, in part, but might be much controlled by complex submarine topography, highly varied tidal currents and surrounding land geology in the study area. Igeo (index of geoaccumulation) representing metal condensation in the sediments moderately/strongly polluted in Co and Cr and moderately polluted in Cu and Ni. But notable metal condensations are not found in the study area. So, it might be interpreted that grain size and metal content distribution tendencies in the sediments are considerably influenced by complex submarine topography, highly varied tidal currents and surrounding land geology.

Geochemical Characteristics of Intertidal Surface Sediments along the Southwestern Coast of Korea (한국 서해남부 조간대 표층 퇴적물의 지화학적 특성)

  • Hwang, Dong-Woon;Ryu, Sang-Ok;Kim, Seong-Gil;Choi, Ok-In;Kim, Seong-Soo;Koh, Byoung-Seol
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.43 no.2
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    • pp.146-158
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    • 2010
  • In order to evaluate the characteristics of sediments and pollution by organic matter and metallic elements in intertidal sediments along the southwestern coast of Korea, we measured various geochemical parameters, including the mean grain size (Mz), water content (WC), ignition loss (IL), chemical oxygen demand (COD), acid volatile sulfide (AVS), and metallic elements (Al, Fe, Cu, Pb, Zn, Cd, Cr, Mn, Hg, As), in intertidal surface sediments. The Mz of the surface sediments ranged from 2.1 to 8.3$\phi$, indicating that the surface sediments consist of various sedimentary facies, such as sand, slightly gravelly mud, sandy mud, and silt. The IL and COD in surface sediment ranged from 0.8 to 5.5% (mean $2.9\pm1.2%$) and from 3.9 to $13.8\;mgO_2/g{\cdot}dry$ (mean $8.5\pm2.6\;mgO_2/g{\cdot}dry$), respectively, which were lower than the values for surface sediment in areas near fish and shellfish farms or industrial complexes. No AVS was detected at any sampling station, despite various sedimentary facies. Most of metallic elements in surface sediments showed relatively good positive correlations with Mz and IL, which imply that the concentrations of metallic elements are mainly controlled by grain size and the organic matter content. The concentrations of metallic elements, except As, at some stations were considerably lower than those in the Sediment Quality Guideline (Effect Range Low, ERL) proposed by the National Oceanic and Atmospheric Administration (NOAA) in the United States. Similarly, the geoaccumulation index (Igeo) class indicated that pollution by metallic elements in intertidal surface sediment, except As, was moderate or non-existent. Our results imply that the intertidal surface sediments along the southwestern coast of Korea are not polluted by organic matter and metallic elements and are healthy for benthic organisms.

Seasonal Variation of Surface Sediments in 2014 on the Gochang Open-Coast Intertidal Flat, Southwestern Korea (고창 개방형 조간대 표층 퇴적물의 2014년 계절 변화)

  • Kang, Sol-Ip;Ryang, Woo-Hun;Jin, Jae-Hwa;Chun, Seung-Soo
    • Journal of the Korean earth science society
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    • v.37 no.2
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    • pp.89-106
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    • 2016
  • The Gochang open-coast intertidal flat is located in the southwestern coast of Korea (the eastern part of the Yellow Sea), characterized by macro-tidal range, an open-coast type, and sand substrates. This study has investigated seasonal variation in sedimentary facies of surface sediments in the Gochang intertidal flat. In the four seasons of February, May, August, and November, 2014, surface sediments of 252 sites in total were sampled and analyzed along three survey lines. The surface sediments of the Gochang intertidal flat in 2014 consisted mainly of fine-grained sand sediments showing a trend in grain size to be coarser in winter and finer in summer. Based on seasonal wave and tidal level data recorded near the study area, it was interpreted that the seasonal effects of wave were stronger than those of tide as a factor controlling surface sedimentation. High waves in winter resulted in the coarsening trend of grain size in surface sediments, whereas, during summer time, the sediments became finer by relatively low waves. Spatial sedimentary facies of the Gochang intertidal flat in 2014 represented that seasonal deviation of the upper tidal zone was larger than that of the lower tidal zone, hence sediments getting coarser in grain size and poorly sorted in the upper tidal zone. From upper to lower tidal zone, the grain size became finer and sediments were better-sorted, showing smaller seasonal deviations.

Factors Affecting the Wintering Habitat of Major Fishery Resources in Southwestern Korean Waters

  • Kim, Jin-Yeong;Choi, Il-Su;Kim, Joo-Il;Choi, Seok-Gwan;Chun, Young-Yull
    • Ocean Science Journal
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    • v.42 no.1
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    • pp.41-48
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    • 2007
  • We investigated the temperature and salinity effects on the major fish species in the wintering grounds based on trawl surveys and oceanographic observations in the southwestern waters of Korea during March-early April in 2002-2003. The influence area of warm Kuroshio water was limited to the southwestern area of Korea in 2003 with a range of $7.7-16.3^{\circ}C$, 32.54-34.70 of salinity, wider than that of 2002. The number of fish species and density of major fish species in 2003 were higher than in 2002. Geographical estimation showed high proportions of species number and catches in the areas around Jeju Islands, southwestern waters and the southeastern coast of Korea. Five species; silver pomfret (Pam pus echinogaster), hairtail (Trichiurus lepturus), anchovy (Engraulis japonicus), Small yellow croaker (Larimichthys polyactis) and yellow goosefish (Lophius litulon) were most abundant, composing above 60% of the total catch in 2002 and 2003. More than 50% of catch in the major fish species were mostly distributed in the range of $9.5-11.0^{\circ}C$ of temperature and 33.1-33.9 of salinity. Non-parametric estimation for the major species showed the 1st mode around $10^{\circ}C$ and the 2nd mode at $8-9^{\circ}C$ in 2002 and $11-14^{\circ}C$ in 2003. Among major fish species, hairtail was principally composed of juveniles, and larger individuals were caught in southeastern waters. These results are considered to be helpful for the area-based fishery management strategy for the wintering grounds of the Yellow Sea and coastal waters of Korea.

A New Record of Glycerid Polychaete, Glycera fallax (Polychaeta: Glyceridae) from Korea

  • Choi, Hyun Ki;Jung, Tae Won;Yoon, Seong Myeong
    • Korean Journal of Environmental Biology
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    • v.33 no.3
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    • pp.274-278
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    • 2015
  • A newly recorded glycerid polychaete collected from mud of the tidal flat in the southwestern coast of Korea is identified as Glycera fallax Quatrefages, 1850 based on the morphologies of papaillae and ailerons on proboscis, parapodial postsetal lobes, and branchiae. In this paper, we provide a detailed description and illustration of Korean materials of this species and a key to the species of the genus Glycera from Korean waters.

Redescription of Desmotimmia mirabilis (Timm, 1961) (Nematoda, Desmoscolecida, Desmoscolecidae) from South Korea

  • Chang, Cheon-Young
    • Animal Systematics, Evolution and Diversity
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    • v.24 no.2
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    • pp.199-203
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    • 2008
  • Desmotimmia mirabilis (Timm), a rarely known desmoscolecid nematode species, was discovered for the first time from the Yellow Sea off southwestern coast of Korea. This is the third record of the species, and the first report from the northwestern Pacific region. Redescription is prepared on the basis of a male specimen from South Korea.

Summer Marine Algal Vegetation of Uninhabited Islands in Sinangun, Southwestern Coast (남서해안 신안군 무인도서의 하계 해조식생)

  • Oh, Byoung-Geon;Lee, Jae-Wan;Lee, Hae-Bok
    • ALGAE
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    • v.20 no.1
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    • pp.53-59
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    • 2005
  • The objective of this study was to clarify marine algal flora and community structure of 16 uninhabited islands in Sinangun area, south western coast of Korea. As a result, a total of 63 species - 11 greens, 16 browns and 36 reds - was identified. The functional groups of marine algal species were filamentous 14.3%, foliose 20.5%, corticated 45.3%, leathery 13.7%, and articulated calcareous algae 6.2%. The (R+C)/P value was calculated as 2.9 showed temperate flora. The result of DCA showed that 16 uninhabitated islands tend to be distributed eastern and western parts. The dominant species was Ulva pertusa, while the subdominats were Gelidium divaricatum, Myelophycus simplex. The vertical distribution pattern of intertidal marine algae represented three distinct zones; Gloiopeltis furcata, Myelophycus simplex, Gelidium divaricatum - Ulva pertusa, Enteromorpha spp., Ishige okamurae - Ulva pertusa, Sargassum thunbergii, Symphyocladia latiuscula.