• Title/Summary/Keyword: Lake Soyang.

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Organic Matter Sources in a Reservoir (Lake Soyang); Primary Production of Phytoplankton and DOC, and External Loading (식물플랑크톤의 세포외배출유기물을 고려한 소양호의 1차생산과 유기물 부하)

  • Nam, Kung-Hyun;Hwang, Gil-Son;Choi, Kwang-Soon;Kim, Chul-Goo;Kim, Bom-Chul
    • Korean Journal of Ecology and Environment
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    • v.34 no.3 s.95
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    • pp.166-174
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    • 2001
  • The autochthonous and allochthonous organic carbon loading were measured in Lake Soyang, to estimate the amount of carbon loading into the lake and the contribution of their sources to tile lake's carbon loading. Autochthonous carbon loading was estimated from phytoplankton primary production with the extracellular organic carbon (EOC). Allochthonous loading was determined by measuring dissolved organic carbon (DOC) and particulate organic carbon (POC) concentration in the main inflowing Soyang River. Both autochthonous and allochthonous organic carbon loading were high during the svmmer, from July to September, and accounted for 43.2% and 71.7% of the annual loading, respectively. Primary productivity was elevated up to $1,000\;mgC\;m^{-2}\;d^{-1}$ during summer and lowest in winter. EOC production from phytoplankton was also large in summer, resulting in a high DOC concentration in the lake water. Primary production of phytoplankton and allochthonous organic matter loading from the watershed contributed to 53.6% and 46.4% of total loading, respectively. The EOC production accounted far $4.4{\sim}21.2%$ of POC primary production, implying that EOC production of phytolankton must be considered in estimation of primary production.

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Elemental Stoichiometry of Natural Phytoplankton Communities in Reservoirs of the Han River Systems (한강수계 주요 댐호의 식물플랑크톤 군집 세포내 화학양론)

  • Park, Hae-Kyung
    • Journal of Korean Society on Water Environment
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    • v.30 no.6
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    • pp.665-672
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    • 2014
  • Elemental cellular stoichiometry of natural phytoplankton communities was examined in six large dam reservoirs in the Han River system. Carbon (C) and nitrogen (N) contents of the phytoplankton-dominated seston from Lake Soyang was higher than that from other lakes. Phosphorus (P) content showed slight variations among six lakes in the range of $0.04{\sim}0.18{\mu}mol$ P mg $DW^{-1}$. The phosphorus concentrations of lake water showed obvious positive relationship with P and C contents of the phytoplankton-dominated seston. In all six lakes, N:P ratios and C:P ratios in the phytoplankton-dominated seston were more than 23 and 133 respectively, indicating the phytoplankton communities in six lakes have been exposed in phosphorus limited condition. The relative abundance of diatoms showed significant negative correlation with C, N, P contents of the phytoplankton-dominated seston and that of cyanobacteria showed significant positive correlation. Elemental stoichiometry of diatoms-dominated seston showed distinctive less content than that of cyanobacteria-dominated seston. The cellular N:P ratios of diatoms- and cyanobacteria-dominated seston indicate that both main classes of phytoplankton in six lakes are in phosphorus deficiency. Elemental stoichiometry of the phytoplankton-dominated seston in this study could be used for the further ecological stoichiometric studies in six lakes.

The evaluation of the eutrophication for the lakes by phosphorus loading (총인부하량을 이용한 인공호의 부영양화 평가)

  • 김재윤
    • Journal of Environmental Science International
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    • v.12 no.7
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    • pp.689-695
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    • 2003
  • The purpose of this study is to evaluate and to predict of eutrophication in lakes by using Vollenweider-OECD model and total phosphorus concentration and inflow rate which were measured in 1993∼2001. The results of study were as follows. The annual total phosphorus loading from the watershed was calculated to be 55∼195tP/yr at lake Soyang, 221∼466tP/yr at lake Taechong, 123∼278tP/yr at lake Andong, 57∼109tP/yr at lake Seomjin. These are discharged, far the most parts, from population and fishfarm facility. TP loading on the surface area at lake Soyang was 3.01gP/㎡/yr, 2.82gP/㎡/yr, 2.84gP/㎡/yr, 3.03gP/㎡/yr, 2.34gP/㎡/yr, 1.78gP/㎡/yr, 0.91gP/㎡/yr, 0.89gP/㎡/yr, 0.86gP/㎡/yr, lake Taechong was 6.71gP/㎡/yr, 7.25gP/㎡/yr, 7.24gP/㎡/yr, 6.53gP/㎡/yr, 6.50gP/㎡/yr, 7.06gP/㎡/yr, 7.04gP/㎡/yr, 4.05gP/㎡/yr, 3.44gP/㎡/yr and TP loading on the surface area of lake Andong, lake Soemjin were 5.39gP/㎡/yr, 4.47gP/㎡/yr, 4.56gP/㎡/yr, 4.45gP/㎡/yr, 3.33gP/㎡/yr, 2.38gP/㎡/yr, 2.53gP/㎡/yr, 2.46gP/㎡/yr, 2.54gP/㎡/yr, 4.09gP/㎡/yr, 4.10gP/㎡/yr, 3.98gP/㎡/yr, 3.73gP/㎡/yr, 2.80gP/㎡/yr, 3.46gP/㎡/yr, 3.22gP/㎡/yr, 2.19gP/㎡/yr, 2.13gP/㎡/yr respectively. The tropic states of four lakes can be assessed as eutrophy because phosphorus leading exceeds the critical phosphorus loading by Vollenweider-OECD model.

Fluctuation of Introduced Fish and Characteristics of the Fish Community in Lake Soyang (소양호의 도입어종 변동과 어류 군집 특성)

  • Byeon, Hwa-Keun
    • Korean Journal of Environment and Ecology
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    • v.29 no.3
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    • pp.401-409
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    • 2015
  • The fish community and introduced fish were surveyed at eight stations of Lake Soyang from March to October, 2013. A total of 41 species of twelve families were collected from the survey stations and among them, two species: Hemibarbus mylodon and Siniperca scherzeri (albino type) were identified as natural monument. There were fifteen Korean endemic species (36.6 %) including Acheilognathus yamatsutae. When compared with previous data (2003), A. yamatsutae, Pseudorasbora parva, Sarcocheilichthys nigripinnis morii, Sarcocheilichthys variegatus wakiyae, Orthrias nudus, Leiocassisuss ussuriensis, Oncorhynchus mykiss, and Micropterus salmoides appeared new in the lake. Dominant species were Hypomesus olidus (St. 1, 3, 6, 7, 8), Lepomis macrochirus (St. 2, 4) and Zacco platypus (St. 5). Of the 12 introduced species fishes in Lake Soyang, Anguilla japonica, Hemiculter eigenmanni, H. nipponensis, Rhinogobius giurinus and Tridentiger brevispinis were introduced and released from other native river water zones in Korea but Cyprinus carpio (Israeli type), Carassius cuvieri, O. mykiss, Ictalurus puntatus, L. macrochirus, and M. salmoides originated from foreign countries.