• Title/Summary/Keyword: estuaries

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On Climatic Characteristics in the East Asian Seas by satellite data(NOAA, Topex/Poseidon) (위성자료(NOAA, Topex/Poseidon)를 이용한 한반도 주변해역의 기후적 특성 연구)

  • 윤홍주;김상우;이문옥;박일흠
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2001.10a
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    • pp.290-294
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    • 2001
  • Satellite data, with Sea Surface Temperature(SST) by NOAA and Sea Level(SL) by Topex/poseidon, are used to estimate characteristics on the variations and correlations of SST and SL in the East Asian Seas from January 1993 through May 1998. In the oceanic climate, the variations of SL shown the high values in the main current of Kuroshio and the variations of SST shown not the remarkable seasonal variations because of the continuos compensation of warm current by Kuroshio. In the continental climate, SL shown high variations in the estuaries(the Yellow River, the Yangtze River) with the mixing the fresh water in the mouth of estuaries of the saline water in the coasts of continent and SST shown highly the seasonal variations due to the climatic effect of continents. In the steric variations in summer, the eastern sea of Japan, the East China Sea and the western sea of Korea shown the increment of sea level with 10~20cm. But the Bohai bay in China shown relatively the high values of 20~30cm due to the continental climate. Generally the trends of SST and SL increased during all periods. That is say, the slopes of SST and SL presented 0.29$^{\circ}C$/year and 0.84cm/year, respectively. The annual and semi-annual amplitudes shown a remarkable variations in the western sea of Korea and the eastern sea of Japan.

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Effects of Estuarine Dam on Fish Assemblage in Danghang Bay of the South Sea, Korea (남해 당항만 하구둑 유무에 따른 어류상 비교)

  • Park, Jun-Su;Gwak, Woo-Seok
    • Korean Journal of Ichthyology
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    • v.31 no.2
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    • pp.83-89
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    • 2019
  • The effect of estuarine dams on fish assembladge in Danghang Bay of Goseong, Korea was determined using monthly samples collected by a beam trawl and a cast net at the natural estuaries and damed estuary from September 2011 to August 2012. In the natural estuaries without dam, salinity was relatively high showing a large diurnal change. Estuarine fishes such as striped sandgoby, Acentrogobius pflaumii and yellowfin goby, Acanthogobius flavimanus, were dominantly caught in the sea side water. In the dammed estuary, freshwater species such as pale chub, Zacco platypus and triden goby, Tridentiger brevispinis were dominanlty caught. The dam in the Danghang estuary have significant effects on the fish assemblage through aquatic environmental change such as salinity.

The Budget of Nutrients in the Estuaries Near Mokpo Harbor (목포항 주변 하구역의 영양염 수지)

  • Kim, Yeong-Tae;Choi, Yoon-Seok;Cho, Yoon-Sik;Oh, Hyun-Taik;Jeon, Seung-Ryul;Choi, Yong Hyeon;Han, Hyoung-Kyun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.6
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    • pp.708-722
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    • 2016
  • Land-Ocean Interactions in the Coastal Zone (LOICZ) models for nutrient budgets were used to estimate the seasonal capacity of the Youngsan Estuary and Youngam-Geumho Estuary to sink and/or supply nutrients such as dissolved inorganic phosphorus (DIP) and nitrogen (DIN) to provide an understanding of the behavior of the coupled biogeochemical cycles of phosphorus and nitrogen in the estuaries (Youngsan Estuary, Youngam-Geumho Estuary) near Mokpo Harbor. During non-stratified periods (May, September, and November, 2008), simple three-box models were applied in each sub-region of the system, while a two-layer box model was applied during on-site observation of stratification development (July, 2008). The resulting mass-balance calculation indicated that even after large discharges from artificial lakes (in May and July), DIP influxes due to a mixing exchange ($V_{X-3}$, or $V_{deep}$) were more than terrigenous loads, indicating the backward transportation of nutrients from a marine source. The model results also indicated that for nutrient loads (DIP and DIN fluxes) in September, an extreme congestion of nutrients occurred around the mouths (sub-region III of the model) of the estuaries, possibly due to an imbalance in physical circulations between the estuaries and offshore locations. In November, the Youngam-Geumho Estuary, into which freshwater was discharged from artificial lakes (Youngam and Geumho Lake), showed nutrient enrichment in the water column, but the Youngsan Estuary showed nutrient depletion. In conclusion, to efficiently control water quality in the estuaries near Mokpo Harbor, integrated environmental management programs should be implemented. I.e., the reduction of nutrient loads from land basins as well as the deposit of nutrient loads into adjacent coastal lines.

Using GIS to Estimate Estuarine Wetlands in Three Major Estuaries and to Quantify Wetland Changes over the Last Century (GIS를 활용한 하구의 습지추정 및 변화추이 분석에 관한 연구)

  • Rho, Paikho;Lee, Chang-Hee
    • Journal of Wetlands Research
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    • v.9 no.2
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    • pp.21-31
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    • 2007
  • Estuarine wetland, where freshwater meets saltwater, is a transitional ecosystem that is valuable ecologically for a variety of reasons, such as feeding and breeding sites for birds, fish, and wildlife. However, research on the spatial distribution and temporal dynamics of estuarine wetlands in Korea is rare. As a fundamental basis for wetland conservation, this study quantified the wetlands in three major estuaries, and evaluated the temporal dynamics of the wetlands since the 1910s. In particular, this study classified the wetland types into mud flat, sand, and emergent-plant types, and estimated the change of each wetland type, using topographic maps produced in the 1910s, 1970s, and 2000s. The wetlands in both the Han and Youngsan River estuaries have declined since the 1910s, but the rate of wetland decline was relatively low before the 1970s, compared to that since the 1970s. The impact of human activities, such as the Youngsan Watershed Comprehensive Development Project and the construction of estuary barrages, has disrupted the estuary cycles and destroyed huge amounts of wetland in the Youngsan estuary. By contrast, estuarine wetlands have been preserved in the small Gahwa estuary, and provide a variety of habitats for plants and wildlife. A special management strategy for wetlands should be established as soon as possible.

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Spatial Distribution of Epilithic Diatom Communities in the Estuary of Korean Peninsula (한반도 하구역 부착돌말류의 공간적 분포)

  • Kim, Ha-Kyung;Cho, In-Hwan;Kim, Young-Hyo;Lee, Min-Hyuk;Kim, Yong-Jae;Won, Du-Hee;Hwang, Su-Ok;Byun, Jung-Hwan;Hwang, Soon-Jin;Kim, Baik-Ho
    • Korean Journal of Ecology and Environment
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    • v.51 no.1
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    • pp.1-15
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    • 2018
  • With land-use (cover) and water quality, the distributional characteristics of epilithic diatom communities were studied with 193 samples from estuaries of Korean peninsula between 2015 and 2016. Of total 394 taxa classified, Nitzschia perminuta (19.6%) and N. inconspicua (14.0%) were the 1st and 2nd dominant species. Using a cluster analysis, the epilithic diatom communities of Korean estuaries were divided into four groups (G1-G4). Ecological characteristics of each group were followed: G1 was located in estuaries of the East Sea, and characterized by high forest land-use and high DO and low nutrients; G2 was the eastern part of the South Sea, and characterized by low turbidity and nutrients; G3 was the western part of the South Sea, and characterized by high agriculture, low electric conductivity and low salinity; G4 was the Yellow Sea, and characterized by high nutrients. The environmental factors having significant correlation with diatom distributions were as follows: TN to G1, turbidity to G2, agriculture to G3, and TP to G4. Moreover, the important factors affecting the occurrence of indicator species were forest land-use for Fragilaria construens var. venter in G1, turbidity for Rhoicosphenia abbreviata in G2, urban land- use and total phosphorus (TP) for Bacillaria paradoxa and Hantzschia amphioxys of G3, and TP and turbidity for N. ovalis and Stephanodiscus invistatus of G4. These results collectively indicate that the distribution of epilithic diatom communities in Korean peninsula was largely effected by water quality and land cover/use.

Characteristics of Nutrient Distribution by the Natural and Artificial Controlling Factors in Small Stream Estuary (소하천 하구(남해 당항포)에서 자연적, 인위적 요인이 영양염 분포에 미치는 영향)

  • KANG, SUNGCHAN;PARK, SOHYUN;AN, SOONMO
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.22 no.1
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    • pp.1-17
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    • 2017
  • This study was conducted to investigate the nutrient distribution and controlling factors in small stream estuaries. The seasonal variations of nutrient concentration (nitrate, ammonium and phosphate) were observed from 2010 to 2012 in the three streams located in Dang-hang (closed estuary: Go-seong, open estuary: Gu-man and Ma-am). The nutrient concentrations in Go-seong were significantly higher than other estuaries, because Go-seong is relatively large and has large nutrient load from the watershed. The dyke located at the estuary, also, caused the high nutrient concentration by reducing the dilution and increasing residence time. In all three streams, nitrate concentration was high at upstream and decreased toward the downstream, because high load of nutrient input were located at upstream. Dilution and biogeochemical removal toward the downstream also caused the trends. Especially, denitrification, a typical nitrogen removing process showed clear tendency of gradual decreasing from upstream to downstream. However, Ammonium and phosphate concentrations were high at upstream and decreased toward the downstream only when the nutrient loads from the rivers were high. Nutrient concentrations were low in summer and high in winter. Freshwater discharge in summer caused a decrease of the residence time and increase of the transport of nutrients to downstream and reduced the nutrient concentrations in the estuary. Nutrient removal by the biological production during high temperature periods also affected the low nutrient concentrations. Small stream estuaries showed distinct nutrient dynamics. It is necessary to understand these characteristics in order to properly manage the small stream estuary.

The Biology of Neomysis awatschensis (Crustacea: Mysidacea) in Korea. 1. Systematics (한국산 곤쟁이, (갑각망:곤쟁이목)의 생물학적 연구 1. 분류학적인 기재)

  • 유광일;최승민
    • 한국해양학회지
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    • v.20 no.2
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    • pp.61-66
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    • 1985
  • A mysid, Neomysis awatschensis(Brandt), which distributes abundantly in brackish lakes, estuaries and salt marshes along the southern and western coast of Korea, from Kimhae to Inchon is described and recorded as new to Korea. The world distribution of the species are also revised with short discussion.

Three Cletodid Copepods of the Genera Limnocletodes and Kollerua (Harpacticoida, Cletodidae) from Coastal Marshes and Estuaries in South Korea

  • Lee, Ji-Min;Chang, Cheon-Young
    • Ocean Science Journal
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    • v.42 no.4
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    • pp.255-267
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    • 2007
  • Three brackish-water harpacticoid species belonging to the family Cletodidae are reported from the salt marshes in South Korea: Limnocletodes behningi Borutzky, 1926, L. angustodes Shen and Tai, 1963 and Kollerua longum (Shen and Tai 1979). Two genera, Limnocletodes and Kollerua, and the three species are newly added to Korean fauna. This paper deals with the redescription and systematic accounts of them, with detailed illustrations.

Two Brackish Cyclopoid Copepods from Southern Coast of Korea

  • Yoon, Hong-Ju;Chang, Cheon-Young
    • Animal Systematics, Evolution and Diversity
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    • v.24 no.3
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    • pp.241-250
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    • 2008
  • Two brackish cyclopoid species are reported mostly from the estuaries and salt marshes in the southern coast of Korea: Limnoithona sinensis (Burckhardt, 1913) and Apocyclops borneoensis Lindberg, 1954. The two species as well as the genera are newly added to Korean fauna. Herein, the redescription is provided with the systematic accounts and detailed illustrations of them.

Six species of the cumacea (Crustacea: Malacostraca) from the intertidal flats surrounding the Yellow Sea

  • Hong, Jae-Sang;Park, Mi-Ra
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2000.05a
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    • pp.363-365
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    • 2000
  • The cumacean fauna currently contains more than 1200 species worldwide (Wafting, 1997). Many of the habitats where cumaceans are likely to be found, such as estuaries, shallow embayments, beaches, tidal flats, and the inner continental shelf, have not yet had their cumacean fauna documented (Watling, 1997). (omitted)

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