• 생태와환경
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• 제42권4호
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• pp.432-440
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• 2009

During the period of past fifteen years (1992~2006), variations of chlorophyll a in relation with water quality in freshwater reservoirs were investigated. This study compared total nitrogen (TN), total phosphorus (TP), chlorophyll a, Secchi depth (SD) and total suspended solids (TSS) between terrestrial freshwater reservoir and coastal freshwater reservoir systems based on their location. Regression analyses (linear and non-linear regressions) were applied for all study sites to examine relationship and interaction of these factors in the freshwater systems from in-land to coasts. The results demonstrated that chlorophyll a was significantly correlated to total phosphorus ($R^2=0.94$, P<0.0001) and was remarkably related to TSS increase ($R^2=0.63$, P<0.0001) in the selected reservoirs. The TN : TP ratio in the reservoir systems was higher than Redfield ratio (16 : 1) indicating that the reservoirs are potentially experiencing P limitation. Water quality of coastal freshwater reservoir system was more significantly decreased than the reservoirs located in in-land during the past fifteen years. The strict management of nutrient discharge into freshwater systems should implemented in the coastal reservoirs since the freshwater is introduced into coastal estuarine systems.

• 한국환경생태학회지
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• 제9권1호
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• pp.42-48
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• 1995

충청북도 제천시의 상수도 취수를 목적으로 건설하는 취수장 예정지를 중심으로 평창강의 담수어류상을 1994년 9월 25일과 1994년 10월 7일부터 1994년 10월 9일까지 두 차례 조사하고 하천 유지수량의 변동이 어류의 생태에 미치는 영향을 조사하였다. 6개 조사 지역에서 총 6과 21속 28종의 담수어류가 관찰되었으며 천연기념물 및 한국 특산종이 많이 관찰되었다. 평창강은 사행천으로 다양한 담수어류가 서식하기에 적합한 환경과 유지수량을 갖는다. 취수를 위한 급격한 유지 수량의 감소는 평창강의 담수어류가 대부분 멸종할 우려가 매우 높다.

• 생태와환경
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• 제56권3호
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• pp.250-258
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• 2023

담수해파리는 담수에서만 발견되는 해파리로써 다양성은 낮지만 전 세계적으로 보고 되고있다. 하지만 이들의 생태 및 발생 원인에 대해서는 정확하게 밝혀진 바가 없다. 따라서 모니터링을 통해 유생에서 폴립(polyp)단계를 통해 성장하는 담수해파리의 분포를 파악하는 것은 이들의 생태를 이해하는 데 중요하다. 본 연구는 미호강 수계 생물막(biofilm)의 환경유전자(eDNA)를 이용하여 담수해파리의 COI 유전자를 탐색하고 환경유전자를 이용한 담수해파리 탐색 가능성을 확인하고자 하였다. 미호강 수계 내 12개 지점 중 8개 지점에서 담수해파리 유전자가 확인되었으며, 대부분 상류에 저수지가 위치한 특성을 보였다. 이들 유전자는 대표적인 담수해파리로 알려진 소워비꽃모자해파리(Craspedacusta sowerbii)의 유전자로 확인되었으며 미호강 조사 지점에서 발견된 C. sowerbii는 이탈리아에서 발견된 종과 같은 계통이었다. 결과적으로 생물막의 환경유전자를 이용한 담수해파리 유전자 탐색방법은 담수해파리 출현 가능성이 높은 지역을 선택적으로 빠르게 선별(screening)할 수 있으며 이는 국내 담수해파리의 분포와 발생기작을 이해하는 데 중요한 단서를 제공할 수 있을 것으로 판단된다.

• 해양환경안전학회지
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• 제20권3호
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• pp.270-276
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• 2014

Seasonal characteristics of water and sediment qualities and potential effects of the freshwater discharge from a small tide embankment interior in a coastal area in Goheung county were investigated from May to September in 2012. Chemical oxygen demand values (COD) were mostly higher than 2 mg/L in summer ebb tide, which exceed the standard value of water quality criteria II of acceptable level for aquaculture activities. Nitrogen and phosphorus were found as the limiting nutrients for algae growth in summer and fall and in spring, respectively. Nitrogen was the limiting nutrient for diatom growth in the whole studied period. The sudden high values of COD, ammonia, dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) were found in water sample collected from station 5 which located in front of the tide embankment sluice gate during spring ebb tide. The freshwater discharge form the tide embankment interior maybe affected the survey areas during a short time interval. Mean values of eutrophication index of the surveyed coastal region in spring, summer and fall were all bigger than 1. Water quality was mostly considered at level II which acceptable for aquaculture activities. Sediment quality in this study was generally in the range of standard for fisheries environment.

• 한국수산과학회지
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• 제54권4호
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• pp.480-488
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• 2021

The term residence time is defined as the time taken for substances in a system to leave the system and is a useful concept to explain the physical environment characteristics of a coastal area. It is important to know the spatial characteristics of the residence time to understand the behavioral properties of pollutants generated in a marine system. In this study, the spatial distribution of average residence time was calculated for Gangjin Bay, Korea, using a hydrodynamic model including a particle tracking module. The results showed that the average residence time was about 10 days at the surface layer and about 20 days at the bottom layer. Spatially, this was the longest residence time in the southwestern sea. There was no significant difference in average residence time at the surface layer due to freshwater discharge, but spatial variation at the bottom layer was larger. The average residence time at the bottom layer decreased in the southwestern area due to freshwater discharge and increased in the northern area. This result suggests that the residence time of anthropogenic pollutants may have a large spatial difference depending on the freshwater discharge, and thus the time taken to influence cultured organisms may also vary.

• 한국물환경학회지
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• 제27권3호
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• pp.364-370
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• 2011

Water quality criteria for human health protection are derived based on the human health risk assessment. Water quality criteria in Korean freshwater bodies have been derived according to the equations developed by the US Environmental Protection Agency. The equations include the fish intake parameter, which is very important factor that significantly influences on the criteria derivation. So far, several fish intake values were used in human health risk assessment for water quality standards and effluent standards. However, these values are not consistent and they refer to various sources. Therefore, there is a need to suggest the most appropriate value of fish intake parameter to derive freshwater quality criteria in Korea. In this study, national and international fish intake values were widely collected and evaluated to select the adequate value of fish intake parameter that can be applied in Korea. The USEPA presented fish intake parameter as the 17.5 g/day for general adults and sport fishers and 142.4 g/day for subsistence fishers. In Korean reports, wide range values of 2 to 67.7 g/day were suggested as fish intake value. These values included finfish and shellfish intakes in common but had various habits. This study found that the 52.4 g/day suggested in Korean Exposure Factors Handbook published by the Ministry of Environment in 2007 seemed to be the suitable fish intake parameter to derive the freshwater quality criteria in Korea. The value is based on water corrected intakes of finfish and shellfish present in freshwater and coastal areas. We expect that this report can be useful to select suitable fish intake value in human health risk assessment for establishing freshwater quality standard in Korea.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 INTERNATIONAL SYMPOSIUM ON SOIL & GROUNDWATER ENVIRONMENT
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• pp.224-225
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• 2005

• 생태와환경
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• 제52권1호
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• pp.28-39
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• 2019

This study was conducted to elucidate microplastics detection of freshwater ecosystems in Geum river. Samples are collected at 6 points in freshwater, 5 points in fishes. Freshwater was sampled 100 L per each points and fish species were Opsariichthys uncirostris amurensis, Hemibarbus labeo, Pseudogobio esocinus, Zacco platypus, Micropterus salmoides and Cyprinus carpio. FTIR analyis was adopted to identify microplastic types. Extracted microplastics were PES (polyester), PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PVC(Polyvinyl chloride) in freshwater, and PES, PE, PP, PET, PVC in fishes. Our results were expected to be used basic research information for further study in microplastics of freshwater ecosystems.

• Journal of Microbiology and Biotechnology
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• 제28권6호
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• pp.946-956
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• 2018

The gut microbiota of aquatic animals plays a crucial role in host health through nutrient acquisition and outcompetition of pathogens. In this study, on the basis of the high-throughput sequencing of 16S rRNA gene amplicons, we examined the bacterial communities in the gut of freshwater shrimp (Macrobrachium nipponense) and in their living environments (sediment and pond water) and analyzed the effects of abiotic and biotic factors on the shrimp gut bacterial communities. High bacterial heterogeneity was observed in the freshwater shrimp gut samples, and the result indicated that both the surrounding bacterial community and water quality factors (particularly dissolved oxygen and temperature) could affect the shrimp gut bacterial community. Despite the observed heterogeneity, 57 genera, constituting 38-99% of the total genera in each of the 40 shrimp gut samples, were identified as the main bacterial population in the gut of M. nipponense. In addition, a high diversity and abundance of lactic acid bacteria (26 genera), which could play significant roles in the digestion process in shrimp, were observed in the shrimp gut samples. Overall, this study provides insights into the gut bacterial communities of freshwater shrimp and basic information for shrimp farming regarding the application of probiotics and disease prevention.

• 한국물환경학회지
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• 제29권2호
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• pp.165-169
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• 2013

Freshwater fish intake is a critical parameter for deriving water quality criteria and water quality standards for protection of human health based on human health risk assessment. Although the freshwater fish intake parameter should be accurate and representative of Korean fish consumption for the water quality criteria to be reliable, data are limited in Korea and have low reliability. In this study, Korean National Health and Nutrition Examination Survey data from 2008-2010 were analyzed to reevaluate freshwater fish consumption. Based on these results, an average consumption rate of 3.0 g/day per person, a $90^{th}$ percentile consumption rate of 0.0 g/day per person, an average consumption rate of 65.7 g/day per fish consumer, and a $90^{th}$ percentile consumption rate of 153.4 g/day per fish consumer were proposed for derivation of water quality criteria using a conservative approach and various exposure scenarios.