• Title/Summary/Keyword: Brackish

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On the Realities of Hydrach Succession in Brackish Water Lakes and Ecological Restoration Policy (기수호의 습성천이 현상과 생태적 복원정책)

  • Sin, Seung Chun;Park, Yong Gil
    • Journal of Environmental Science International
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    • v.13 no.1
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    • pp.11-17
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    • 2004
  • The purpose of this study is to present the model of ecological restoration through analysis on the condition of hydrach succession process in brackish water lake. To this study, we investigate and research the present condition of brackish water lake in South Korea. Most brackish water lake in South Korea have characteristics that is come into being malignant hydrach succession. Many lakes were reclaimed to increase foodstuff production. And river conservation work seperate lakes from the ocean. In a embryological view, most lakes based on the brackish water lakes, But present lakes show many different types such as a fresh water lake, a salt lake, a brackish water lake, a swamp, and a marshland. As a result, brackish water lakes have greatly damaged by diverse artificial interventions to promote people's activities. Therefore, in order to manage brackish water lakes systematically, criteria of lake preservation must be coincide with the present conditions of hydrach succession in each lake.

Removal of Silica and Humic Acid from Brackish Water with Calcite (Calcite를 이용한 brackish water 내의 실리카와 휴믹산의 제거에 관한 연구)

  • 박소희;박재우
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2002.04a
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    • pp.243-245
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    • 2002
  • Brackish water desalination using reverse osmosis(RO) membrane is more useful and economic than sea water to solve the shortage of fresh water supply because of its low total dissolved solid(TDS) contents. Silica and humic acid in brackish water make serious fouling problems and cause the decline of permeate flux and increase of operating pressure. In this study, the experiments for removal of silica and humic acid were conducted with calcite particles to prevent membrane fouling and investigated the effect of pH of feed water Adsorption of silica to calcite was higher at pH=7.5 than 9.5 and removal rate was increased according to increase of initial concentration of silica. The effect of pH on adsorption of humic acid was not significant but at low initial concentration the adsorption of humic acid was enhanced at pH 7.5. The result of this study expect to apply to brackish water desalination experiment of flat-sheet reverse osmosis membrane.

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Brackish Lakes in Shinpo District, North Korea. I. Zooplankton (북한 신포지구의 기수호 I. 동물플랑크톤)

  • Kang, Yeon-Shik;Kim, Say-Wa
    • Korean Journal of Ecology and Environment
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    • v.36 no.2 s.103
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    • pp.215-220
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    • 2003
  • Three lakes (lake Homanpo, Hyunkum and Daein) were revealed to be brackish by the results of zooplankton fauna and salinities (2.8 ppt and 0.8 at lake Hyunkum in May and October 2002, and 1.5 and 0.5 at the Daein) in Shinpo district, North Korea. Among 34 taxa of zooplankton occurred, copepods and rotifers showed the prosperity in species number with 15 species and 7 species, respectively. Twenty four taxa of freshwater animals, six brackish ones and four marine ones were found, Brackish copepods, Pseudodiaptomus inopinus and Sinocalanus tenellus, were found in all lakes. More than 90% of zooplankton abundances consisted of brackish and marine species in three lakes. The outburst of S. tenellus was observed (59,000 indiv./$m^3$) at lake Hyunkum in May, when the proportion of brackish and marine zooplankton exceeded 99% of total zooplankton abundance. Long-term monitoring appears to be needed to provide basic data to protect brackish lakes in the study area.

A Faunistic Study on the Brackish-water Calanoid Copepods from South Korea

  • Lee, Ji-Min;Yoon, Hong-Ju;Chang, Cheon-Young
    • Animal Systematics, Evolution and Diversity
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    • v.23 no.2
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    • pp.135-154
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    • 2007
  • Eight calanoid species of 4 genera in 4 families are reported from the various brackish waters such as estuaries, brackish-water lakes, and coastal marshes in South Korea. Among them, Eurytemora affinis (Poppe) and Acartia (Acanthacartia) tsuensis Ito are newly added to Korean copepod fauna. Collection data, brief descriptions, illustrations and distribution maps for the eight species are prepared. A key to the genera and species of the brackish-water calanoids from Korea is also presented.

Effect of the Dietary EPA in Replacement Diets for the Culture of Brackish Flea, Diaphanosoma celebensis (기수산 물벼룩의 배양을 위한 대체 먹이원 내 EPA 영향)

  • Park, Jin-Chul;Kwon, O-Nam;Park, Heum-Gi
    • Journal of Fisheries and Marine Sciences Education
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    • v.24 no.2
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    • pp.203-209
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    • 2012
  • We investigated the effect on dietary EPA (eicosapentaenoic acid) source (EP) into formulated diets for growth of brackish flea, Diaphanosoma celebensis. The highest density and specific growth rate (SGR) of brackish fleas were observed on Tetraselmis suecica (TE) trial, but these of trial were not significantly differed with that of Chlorella (CH) + Crypthecodinium sp. (CR) + EP trial, contained EPA oil (P>0.05). Contrastively, CH trial showed the lowest SGR. And in the RNA/DNA ratio, 0.08 of TE trial was the highest ratio out of whole trials, but the trial not significantly differed with that of CH + CR + EP trial (P>0.05). But, the ratio of CH trial was the lowest ratio at 0.05 out of whole trials (P<0.05). Through out results, the EPA source for flea culture was showed a positive effect through their growth and SGR. Therefore, we suggested that a usage of the source with CH could replace T. suecica as good diet for culture of the brackish flea.

Quantitative Assessment of Coastal Groundwater Vulnerability to Seawater Intrusion using Density-dependent Groundwater Flow Model (분산형 해수침투 모델을 이용한 양적 지표 기반의 해안지하수 취약성 평가연구)

  • Chang, Sun Woo
    • Journal of Soil and Groundwater Environment
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    • v.26 no.6
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    • pp.95-105
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    • 2021
  • Extensive groundwater abstraction has been recognized as one of the major challenges in management of coastal groundwater. The purpose of this study was to assess potential changes of groundwater distribution of northeastern Jeju Island over 10-year duration, where brackish water have been actively developed. To quantitatively estimate the coastal groundwater resources, numerical simulations using three-dimensional finite-difference density-dependent flow models were performed to describe spatial distribution of the groundwater in the aquifer under various pumping and recharge scenarios. The simulation results showed different spatial distribution of freshwater, brackish, and saline groundwater at varying seawater concentration from 10 to 90%. Volumetric analysis was also performed using three-dimensional concentration distribution of groundwater to calculate the volume of fresh, brackish, and saline groundwater below sea level. Based on the volumetric analysis, a quantitative analysis of future seawater intrusion vulnerability was performed using the volume-based vulnerability index adopted from the existing analytical approaches. The result showed that decrease in recharge can exacerbate vulnerability of coastal groundwater resources by inducing broader saline area as well as increasing brackish water volume of unconfined aquifers.

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.

Two Harpacticoid Species of Genera Nitokra and Ameira (Harpacticoida: Ameiridae) from Brackish Waters in Korea

  • Chang, Cheon-Young
    • Animal cells and systems
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    • v.11 no.2
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    • pp.247-253
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    • 2007
  • A new species of Nitokra and Ameira parvula (Claus) belonging to the family Ameiridae are recorded from brackish waters in South Korea. Nitokra koreanus n. sp. most resembles N. spinipes and N. pietschmanni, however, it is characteristic in having the character combination of ellipsoidal P5 exopod and very short P1 enp 1. Ameira parvula is reported for the first time from the Northwestern Pacific. Description of the new species and the taxonomic accounts of both species are presented.

New Record of brackish water snail, Iravadia (Fluviocingula) elegantula (Sorbeoconcha:Iravadiidae), in Korea

  • Lee, Jun-Sang;Min, Duk-Ki
    • The Korean Journal of Malacology
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    • v.25 no.3
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    • pp.211-212
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    • 2009
  • One Iravadiid shell Iravadia (Fluviocingula) elegantula (A. Adams, 1861), from the brackish waters in Kangwon-do was recorded as new to the Korean molluscan fauna. The shell is typically solid and narrowely ovate-conic. The protoconch is small, planorboid to depressed dome-shaped, typically with a minute first whorl. Including the new records in this study, the family Iravadiidae contained 2 genera and 3 species in the Korean water.

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Identification of Acanthotrema felis (Digenea: Heterophyidae) metacercariae encysted in the brackish water fish Acanthogobius flavimanus

  • Sohn, Woon-Mok;Han, Eun-Taek;Seo, Min;Chai, Jong-Yil
    • Parasites, Hosts and Diseases
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    • v.41 no.2
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    • pp.101-105
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    • 2003
  • The metacercariae of Acanthotrema felis Sohn et at., 2003 (Digenea: Heterophyidae) were discovered in a species of the brackish water fish, Acanthogobius flavimanus, in the Republic of Korea. They were experimentally fed to kittens, and adult flukes were harvested 7 days later. The adults were morphologically characterized by the presence of a bipartite seminal vesicle, the ventral sucker associated with a ventrogenital sac enclosing 3 sclerites (2 long and pointed, and 1 short and thumb-like), and an unarmed gonotyl. The adult flukes were identified as A. felis Sohn et al., 2003, and the brackish water fish A. flavimanus has been verified as one of its second intermediate hosts.