• Title/Summary/Keyword: aquatic ecosystem

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The Applicability Assessment of Environmental Flows Method by Hydrological Approach (수문학적 접근법에 의한 환경유량 산정기법의 적용성 평가)

  • Kim, Joo Cheol;Choi, Yong Joon
    • Journal of Korean Society on Water Environment
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    • v.26 no.2
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    • pp.208-214
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    • 2010
  • This study aimed at the introduction of desktop method for assessment of environmental flows developed by International Water Management Institute (IWMI) recently and its application to Geum river basin. This scheme simulated the influence on aquatic ecosystem caused by watershed development and in turn the decrease of water quantity keeping the river's own flow regime. It was found to be as very effective method although it had simple structure. Flow duration curves for different environmental classes at Sutong and Gongjoo sites were estimated according to the natural conditional scenario of Geum river basin and the results were relatively compared well with the previous studies. The behaviors of monthly average runoff time series of both sites showed the level of A class. The results of this study would provide the fundamental data to establish the future plans of monitoring or management for aquatic ecosystem of Geum river basin.

Design of Lake Ecological Observation Data Management

  • Ahn, Bu-Young;Jung, Young-Jin;Lee, Myung-Sun;Jeong, Choong-Kyo;Kim, Bom-Chul
    • International Journal of Contents
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    • v.7 no.1
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    • pp.45-51
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    • 2011
  • To protect water pollution and scarcity in lake and river, water quality monitoring applications have become important tools to understand the change of aquatic ecosystem. KLEON (Korean Lake Ecological Observatory Network) is designed to manage and share the ecological observations. The various kinds of water quality and phytoplankton observations are collected from the selected observatories such as seven lakes/rivers/wetlands. To deeply understand the collected observations with weather, KLEON also manages the observatory information such as lake, dam, floodgate, and weather. The accumulated observation and analyzed results are used to improve the water quality index of the observatories and encourage the ecologists' cooperation.

PCR of Gut Contents for a Food Web Study of a Marine Ecosystem

  • Kim, Nack-Keun;Kim, Kyoung-Sun;Kim, Hyun-Woo
    • Fisheries and Aquatic Sciences
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    • v.10 no.4
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    • pp.179-185
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    • 2007
  • Understanding dietary habits is one of the most important factors in studying food webs and other ecological processes. Here we designed universal primers to amplify portions of the 18S and 28S rDNA sequences to examine gut contents using PCR techniques. The gut contents of sailfin sandfish (Arctoscopus japonicus) and pacific squid (Todarodes pacificus) were examined. In total, 11 families of prey were identified with 18S and 28S rDNA using the universal primers. The DNA sequence data indicated that the primer sets successfully amplified a wide spectrum of species and represented gut contents in a relatively convenient way. We found that information in the NCBI database was not yet sufficient to discriminate the species we isolated. In addition, technology for the separation of heterogeneous PCR products and better resolution and quantification protocols would help increase data accuracy.

Approximation Method of Environmental Flows based on Flow Duration Curves (유황곡선을 기반으로 한 환경유량의 개략산정법)

  • Kim, Joo-Cheol;Lee, Sang-Jin;Ko, Ick-Hwan;Woo, Dong-Hyun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.933-937
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    • 2010
  • This study aimed at the introduction of desktop method for assessment of environmental flows developed by IWMI(International Water Management Institute) recently and its application to Geum river basin. This scheme simulated the influence on aquatic ecosystem caused by watershed development and in turn the decrease of water quantity keeping the river's own flow regime. It was found to be as very effective method although it had simple structure. Flow duration curves for different environmental classes at Sutong and Gongjoo sites were estimated according to the natural conditional scenario of Geum river basin and the results were relatively compared well with the previous studies. The behaviors of monthly average runoff time series of both sites showed the level of A class. The results of this study would provide the fundamental data to establish the future plans of monitoring or management for aquatic ecosystem of Geum river basin.

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Overfishing and recent risk for collapse of fishery in coastal Mediterranean lagoon ecosystem (Karavasta lagoon, southeastern Adriatic sea)

  • Spase Shumka;Yukio Nagahama;Sarjmir Hoxha;Koji Asano
    • Fisheries and Aquatic Sciences
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    • v.26 no.4
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    • pp.294-303
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    • 2023
  • Beside that the fish species and their sub-populations are highly important as a keystone species in the coastal and marine ecosystem, there are very few studies on their presence, distribution and temporal variations within and around the lagoon ecosystems in Albania. This paper provides an updated review on the life cycle, fishery, exploitation state and management of the main species that are subject of commercial fishing in the Karavasta lagoon, southeastern Adriatic coast of Albania. Due to the fact that lagoons represent a continuum between continental and marine aquatic ecosystems they play a crucial role in species life cycles. Further on in the circumstances of rapid utilizations and environmental changes, anomalies in salinity and temperatures, accelerated anthropogenic influences their rate of vulnerability is highly increased. Following the requirements of the Water Framework Directive, transitional water, coastal lagoons and estuaries there is a need for urgent monitoring and management approaches. The commercial species include: European eel (Anguilla anguilla), species of Family Mugilidae (Mugil cephalus, Liza ramada, Liza salienes and Chelon labrosus), Seabream (Sparus aurata), Seabass (Dincentrarchus labrax), etc. Fish productivity is oscillating from maximum value of 61.95 kg/ha is recorded in period of 1975-80 and lower value of 31 kg/ha in year 2020. Our study highlights importance of fish and fishery long-term monitoring, and contributes to understand the driving factors in productivity, migration patterns and species ecology in the vital coastal ecosystems.

Sensitivity Analysis of High and Low Flow Metrics to Climate Variations

  • Kim, Jong-Suk;Jang, Ho-won;Hong, Hyun-Pyo;Lee, Joo-Heon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.355-355
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    • 2018
  • Natural hydrology systems, including high flow and low flow events, are important for aquatic ecosystem health and are essential for controlling the structure and function of ecological processes in river ecosystems. Ecosystem responses to flow changes have been studied in a variety of ways, but little attention has been given to how episodic typhoons and atmospheric circulation patterns can change these hydrologic regime-ecological response relationships. In this diagnostic study, we use an empirical approach to investigate the salient features of interactions between atmospheric circulation, climate, and runoff in the five major Korean river basins.

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Vulnerability Assessment of Water Quality and Aquatic Ecosystem to Climate Change in Korea using Proxy Variables (대리변수를 이용한 한반도 수질 및 수생태계 부문의 기후변화 취약성 평가)

  • Lee, Keon Haeng;Chung, Eu Gene;Kim, Kyunghyun;Yu, Jeong Ah;Lee, Eun Jeong
    • Journal of Korean Society on Water Environment
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    • v.28 no.3
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    • pp.444-452
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    • 2012
  • This study aims at assessing vulnerability of water quality and aquatic ecosystem to climate change by using proxy variables. Vulnerability to climate change is defined as a function of exposure to climate, sensitivity, and adaptive capacity. Detailed proxy variables were selected considering availability and then standardized by re-scaling concept. After adequate weights were assigned to standardized proxy variables by Delphi technique, vulnerability index was calculated. As results, vulnerability of adjacent regions to coastal areas include water quality and aquatic ecosystem is relatively higher than that of inland areas, and especially adjacent region to the western and southeast seas, and Jeju show high vulnerabilities. Vulnerability in the future was performed based on A1B scenario (IPCC, 2000). Temporally, the increase of vulnerability from 2050s to 2100s may be larger than the increase from 2000s to 2050s. Because vulnerability index was estimated through the relationship among various proxy variables, it is important to consider characteristics of local region with measurements and policies for reduction of sensitivity and enhancement of adaptive capacity on climate change. This study is expected to be useful in planning adaptation measures and selecting priority to the policy on climate change.

Fish Fauna and the Health Assessment of Independent Streams Flowing into the Yellow Sea in Korea: a Case of the Jeonnam and Jeonbuk Provinces (서해로 유입되는 독립하천의 어류상과 수생태계 건강성 평가: 전남과 전북을 대상으로)

  • Kim, Jin-Jae;Joo, Hyun-Soo
    • Korean Journal of Environmental Biology
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    • v.35 no.4
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    • pp.533-544
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    • 2017
  • In this study, the fauna of freshwater fish were investigated from March until October of 2016 in 24 independent streams in the Jeonnam and Jeonbuk provinces, which were flowing into the Yellow Sea. The health of the aquatic ecosystem in those streams was assessed through the biological and abiological character index (BAc index). During the surveyed period, a total of 4,127 individuals were collected; they belonged to 59 species of 44 genera in 18 families. The most dominant species identified was Zacco platypus, and 12 species were endemic species of Korea, including Rhodeus uyekii. The BAc index indicated a statistically significant correlation (p<0.01 or 0.05). The stage distribution of the aquatic ecosystem health assessment showed the highest rating of 41.7% at the "Fair" stage. The "Good" and "Poor" stages accounted for 20.8% while the "Excellent" stage took up 16.7%. It has been confirmed that the aquatic ecosystem health of independent streams is influenced more by the abiological character index as a consequence of geographical characteristics and artificial/natural limiting factors, than by the biological character index.

Toxicity Evaluation of Tar Colors by Water Fleas and Luminescent Bacteria (물벼룩과 형광성 박테리아를 이용한 타르색소의 독성평가)

  • Choo, Yeon Jong;Kim, Gun Heung;Kim, Hung Soo
    • Journal of Wetlands Research
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    • v.9 no.1
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    • pp.21-29
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    • 2007
  • In Korea, we assign the chemical substances of 535 types as toxic substance. Only 10% of the 535 toxic substances are being managed by the Ministry of Environment related with water quality standard. Tar color is also one of chemical substances, but we have the lacks for the information of tar colors about the environmental effects of aquatic ecosystem. This study performed the test of bioassay using Water Fleas and Luminescent Bacteria. The tar has 7 types of colors allowed as the edible color and we evaluate the toxicities of 5 tar colors out of 7 colors and we would like to provide the informations for further study as we perform the toxicity test for the samples of 5 tar colors. We did the toxicity test of using Water Fleas From the results, we obtained the magnitudes of toxicity in order of Red No.2, Yellow No.5, Red No.3, Yellow No.4, Blue No.1. As the result based on Microtox Acute Toxicity Test using Luminescent Bacteria with the standard of 15min-EC50, we obtained in order of Yellow No.5, Food Red No.3, Red No.2, Yellow No.4, Blue No.1. We could expect the tar colors may have different effects on the aquatic ecosystem, respectively and it may influence to the aquatic ecosystem and the human, because of bioconcentration by food chain when toxicity of the tar colors overflow in the aquatic ecosystem.

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