• 제목/요약/키워드: freshwater environment

검색결과 597건 처리시간 0.029초

무당개구리 비텔로제닌 유전자의 발현의 RT- PCR 검출법 (RT- PCR Analysis of Vitellogenin Gene Expression in Bombina orientalis)

  • 계명찬;이명식;강희정;정경아;안혜선
    • 환경생물
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    • 제22권2호
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    • pp.329-335
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    • 2004
  • To develop a biomarker for the monitoring of the contamination of estrogenic endocrine disrupters in the aquatic environment, reverse transcription -polymerase chain reaction (RT-PCR) analysis of vitellogenin (Vg) mRNA expression was optimized in Bombina orientalis, a Korean red bellied toad species. Based on partial cDNA sequences of both Vg and beta actin genes of B. orientalis, specific primers for RT-PCR of Vg and beta actin mRNAs were developed. Semiquantitative RT-PCR of the Vg mRNA in liver was optimized using a beta actin mRNA as an internal control in both sexes. In female RT-PCR using $1\;\mu{g}$ of the liver cDNA resulted in a linear increment in the PCR product of Vg from 18 to 34 cycles of amplification. In male, on the contrary, the RT- PCR product was first detected at 30 cycles of amplification and a linear increment was observed from 30 to 40 cycles of amplification, suggesting that male B. orientalis expresses minute amount of Vg mRNA which is a $2^{-12}$ equivalent of female. In conclusion, the optimized protocol for semiquantitative RT-PCR analysis of Vg mRNA level in B. orientalis male liver will be useful for the environmental monitoring the xenoestrogen contamination in the freshwater environment in Korea.

Model development in freshwater ecology with a case study using evolutionary computation

  • Kim, Dong-Kyun;Jeong, Kwang-Seuk;McKay, Robert Ian (Bob);Chon, Tae-Soo;Kim, Hyun-Woo;Joo, Gea-Jae
    • Journal of Ecology and Environment
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    • 제33권4호
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    • pp.275-288
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    • 2010
  • Ecological modeling faces some unique problems in dealing with complex environment-organism relationships, making it one of the toughest domains that might be encountered by a modeler. Newer technologies and ecosystem modeling paradigms have recently been proposed, all as part of a broader effort to reduce the uncertainty in models arising from qualitative and quantitative imperfections in the ecological data. In this paper, evolutionary computation modeling approaches are introduced and proposed as useful modeling tools for ecosystems. The results of our case study support the applicability of an algal predictive model constructed via genetic programming. In conclusion, we propose that evolutionary computation may constitute a powerful tool for the modeling of highly complex objects, such as river ecosystems.

동읍지역 제4기 미고결 지층의 퇴적이력 (Development of Holocene Unconsolidated Stratigraphic Sequence from Lower Reaches of Nagdong River, Dongup Area)

  • 김성욱;최은경;이성훈;이승원;한석희;최상순;전휘채
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2006년도 춘계 학술발표회 논문집
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    • pp.876-881
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    • 2006
  • This study was carried out to understand depositional environment and genesis of clayey soils that distributed in the Dongup area. On the basis of detailed observation and description on mineralogy, geochemical composition, geophysical properties, paleontological analysis of cored sediments, three sedimentary unit have been distinguished. From bottom to top, they are early Holocene freshwater muddy deposit(Unit I, fluvial swamp), late Holocene silt and muddy deposit(Unit II, alluvial deposit), late Holocene muddy deposit(Unit III, fluvial swamp). Unit II is divided into three part: the lower part-unweathered massive silt and muddy deposit, middle part-weathered layered slit and muddy deposit and upper part-weathered massive muddy deposit.

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개념적 유역모델을 이용한 영산강 유역 오염부하 유출량의 시공간적 분포평가 (Estimation of Pollution Loads from the Yeongsan River Basin using a Conceptual Watershed Model)

  • 박민혜;조홍래;구본경
    • 한국물환경학회지
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    • 제30권2호
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    • pp.184-198
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    • 2014
  • For estimating discharge and pollution loads into the Yeongsan lake, a conceptual watershed model HSPF(Hydrological Simulation Program - Fortran) was applied to the Yeongsan River Basin. Various spatial data set including DEM, watershed boundaries and land uses were used to set up the model for the Yeongsan River Basin that was divided into 45 sub-basins. The model was calibrated and validated for the river discharges, SS, BOD, TN and TP concentrations against the data observed in 2011 at several monitoring stations. The simulation results show good agreement with the observed water flows($R^2$ = 0.46 - 0.97, NSE = 0.70 - 0.96). The simulated concentrations of SS, BOD, TN and TP are also in good agreement with the observed. The total freshwater discharge to the Yeongsan lake is estimated $2,406{\times}10^6m^3/year$ which the Jiseok and Hwangryoung stream contribute as much as 19%, 17% respectively. It is estimated that the total discharges to the Youngsan lake is SS 152,327 ton/year, BOD 15,721 ton/year, TN 10,071 ton/year, TP 563 ton/year. Both water and pollution loads are high in summer, particularly in July, when the monsoon season arrives at the Korean peninsula.

Effects of Recombinant Aquaporin 3 and Seawater Acclimation on the Expression of Aquaporin 3 and 8 mRNAs in the Parr and Smolt Stages of Rainbow Trout, Oncorhynchus mykiss

  • Kim, Na Na;Choi, Young Jae;Lim, Sang-Gu;Kim, Bong-Seok;Choi, Cheol Young
    • Ocean and Polar Research
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    • 제38권2호
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    • pp.103-113
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    • 2016
  • This study aimed to examine the role of two aquaporin isoforms (AQP3 and AQP8) in response to the hyperosmotic challenge of transitioning from freshwater (FW) to seawater (SW) during parr and smoltification (smolt) using the rainbow trout, Oncorhynchus mykiss. We examined the changes in the expression of AQPs mRNAs in the gills and intestine of the parr and smolt stages of rainbow trout transferred from FW to SW using quantitative real-time PCR in an osmotically changing environment [FW, SW, and recombinant AQP3 (rAQP3) injection at two dosage rates]. Correspondingly, AQPs were greater during smoltification than during parr stages in the rainbow trout. Plasma osmolality and gill $Na^+/K^+$-ATPase activity increased when the fish were exposed to SW, but these parameters decreased when the fish were exposed to SW following treatment with rAQP3 during the transition to seawater. Our results suggest that AQPs play an important role in water absorbing mechanisms associated with multiple AQP isoforms in a hyperosmotic environment.

Flushing 방류로 인한 섬진강 하구부 염수침입 영향분석 (Analysis of Saltwater Intrusion by Flushing Discharge in the Seomjin River Estuary)

  • 노준우;이진영;신재기
    • 환경영향평가
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    • 제20권3호
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    • pp.325-335
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    • 2011
  • Estuary is a transitional zone between river and ocean environment that receives the maritime and riverine influence simultaneously. Estuaries are the most productive habitats because their incoming water provides large quantities of nutrients. The Seomjin River estuary, located in the middle south of Korea, has no barrage and shows natural characteristic of estuary. However, due to dredging and reclamation the environment of the estuary has been changed significantly in the river mouth. In addition, increased freshwater intake in midstream of the Seomjin River results in salinity intrusion. In this paper salinity variation in downstream estuary of the Seomjin River has been simulated and tested using EFDC model. The results of simulation were compared with measured data collected at three points, Culture & Art Center, Sumjin Iron Bridge, and Mokdori, located at 9Km, 14Km, and 15.5Km respectively from downstream estuary. Based on the simulated results, the contribution of the flushing discharge has been evaluated in preventing the salinity intrusion by increasing the discharge flowrates released from the Juam dam.

국내 호수의 제한영양소와 하수처리장 방류수 인 기준 강화의 필요성 (The Limiting Nutrient of Eutrophication in Reservoirs of Korea and the Suggestion of a Reinforced Phosphorus Standard for Sewage Treatment Effluent)

  • 김범철;사승환;김문숙;이윤경;김재구
    • 한국물환경학회지
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    • 제23권4호
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    • pp.512-517
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    • 2007
  • The limiting nutrient of eutrophication in freshwater bodies in Korea was examined and the phosphorus concentration standard for sewage treatment effluent was discussed. The weight ratio of N/P in 13 major reservoirs showed the range of 18 to 163, which implies phosphorus is more limited than nitrogen for algal growth. In the correlation analysis phosphorus showed higher correlation with chlorophyll-a concentration than with nitrogen. In the algal bioassay phosphorus spike test enhanced algal growth in all 25 samples of five reservoirs, while nitrogen was found to co-limit only in four samples. It confirms that phosphorus is the only limiting nutrient for eutrophication in Korean reservoirs. As many reservoirs are eutrophic in Korea, phosphorus control is critical for the management of water quality. The phosphorus standard of sewage treatment effluent in Korea was compared with other countries, and it can be concluded that phosphorus standard is too high to be effective in eutrophication control and a lower phosphorus standard is essential for the water quality improvement.

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

  • 장선우
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제26권6호
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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.

페놀 화학사고 발생으로 오염된 퇴적물에서 페놀의 거동 기작이 원위치 피복의 정화 효율에 미치는 영향 (Effect of the Fate Mechanisms of Phenol on the Remediation Efficiency of In-Situ Capping Applied to Sediment Contaminated by Phenol Chemical Spills)

  • 이아름;최용주
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제27권1호
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    • pp.60-70
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    • 2022
  • We evaluated the performance of in-situ capping to prevent the release of phenol, one of hazardous chemicals of concern for their impact on sediment. Sediment near the estuary of Hyeongsan River, Korea, and commercially-available sand were collected to evaluate their physical properties and phenol sorption characteristics. Biodegradation kinetics of phenol spiked into the sediment was evaluated under freshwater and estuarine salinity conditions. These experimental measurements were parameterized and used as input parameters for executing CapSim, a software predicting the performance of in-situ capping. The CapSim simulation demonstrated that capping with 50-cm sand reduced the phenol release by several orders of magnitude over 0.25- and 1-year duration for almost all simulation scenarios. The variables tested, i.e., cap thickness, pore-water movement, and biodegradation rate, showed high correlation to each other to influence the extent of phenol release from sediment to the water column. The findings and the framework employed to evaluate the performance of in-situ capping in this study can be adopted to determine whether in-situ capping is appropriate remedial approach at sediment sites impacted by hazardous chemicals due to accidental spills.

물리탐사에 기초한 대수층 특성화 및 적용 사례 분석 (Aquifer Characterization Based on Geophysical Methods and Application Analysis on Past Cases)

  • 정주연;김빛나래;송서영;정인석;송성호;남명진
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제27권2호
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    • pp.1-23
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    • 2022
  • For its essential importance as a resource, sustainable development of groundwater has been major research interests for many decades. Conventional characterization of aquifer and groundwater has relied on borehole data from observation well. Although borehole data provide useful information on yield and flow of groundwater, it is often difficult and sometimes costly to estimate the spatial distribution of groundwater in entire aquifer. Geophysical probing is an alternative techique that provides such information due to its capability to image subsurface structures as well as to delineate spatial distribution of hydraulic parameters. This study presents various technical information about geophysical probing to estimate main characteristics of aquifer for groundwater exploitation. Subsequently, we analyzed representative cases, in which geophysical methods were applied to identify the location of the groundwater, classify freshwater and brine, derive hydraulic constants, and monitor groundwater.