• The Korean Journal of Pesticide Science
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• v.8 no.2
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• pp.117-128
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• 2004

The influence of different feeding rates of three green algae on growth and reproduction in four Korean cladocera, Daphnia sp., Daphnia obtusa, Moina macrocopa, and Simocephalus vetulus was investigated. The growth and reproduction rates of Daphnia sp. fed Chlorella vulgaris cells were significantly increased than those of daphnid fed Senedesmus subspicatus and Selenastrum carpricornutum. The total offsprings of Daphnia sp. fed $25\times10^4$ and $50\times10^4$ cells Chlorella vulgaris for 21days were $124{\pm}2.8$ and $168{\pm}22.1$, respectively. The Daphnia obtusa fed $25\times10^4$ and $50\times10^4$ cells Selenastrum carpricornutum was shown good reproduction rates, $72.2{\pm}7.9$ and $79.6{\pm}22.9$, respectively. The Moina macrocopa fed $25\times10^4$ and $50\times10^4$ cells Senedesmus subspicatus as well as Simocephalus vetulus and $25\times10^4$ and $50\times10^4$ cells Chlorella vulgaris were shown good reproduction rates. All of algae tested were sufficient as a good diet for Korean Cladocerans in this study. However, the preferred alga was Chlorella vulgaris and the optimal feeding concentrations were $2.5\times10^5\sim5\times10^5$ cells/mL, because the alga was shown most stable and generally high production rates in all cladocerans tested.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.370-375
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• 2013

Exotic species in aquatic ecosystem generate various problems domestically as well as globally. Largemouth bass (Micropterus salmoides) which is a well-known exotic species globally, acts as a substantial disturbance factor on the native fish communities in Korea due to the high predation pressure and hence designated as a ecologically harmful species by Ministry of Environment. In this study, we investigated the impact of largemouth bass on Korean native fish population, crucian carp (Carassius auratus), to identify responses of the prey fish. Two fish species were collected at seven reservoirs distributed at the Nakdong River catchment area, and changes in length-frequency and length-weight relationship (LWR) were analysed depending on existence of large-mouth bass. At bass absent sites, ratio of under age 1 year individuals were small, and over age two years were dominant. Conversely, normal length-frequency distribution pattern was identified at bass absent sites. The LWR of crucian carp (fish smaller than total length of 160 mm were only considered as it is frequently consumed by bass predation) was different depending upon bass existence. The value of parameter b at bass absent reservoirs was 2.909, which was smaller than that of bass present reservoirs, 3.100. Our results imply that crucian carp at bass present reservoirs presented a different strategy to survive from predation by bass, through relatively rapid growth. We propose that other native species might have similar growth strategies like crucian carp.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.4
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• pp.193-200
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• 2016

Water flea is a widely used test species in the aquatic ecotoxicity test. In Korea, D. magna is currently used as a standard test species, however that do not inhabit in the Korean aquatic ecosystem. In this study, Daphnia galeata, which is a dominant species in the Korean aquatic ecosystem, was collected from domestic lake and investigated to suggest the D. galeata for ecotoxicity assessment in Korea. We investigated the characteristics, life span, and toxicity sensitivity compared with D. magna. The life span test of D. galeata was performed in this study, and then the results were compared to the sensitivity with D. magna to confirm the applicability for ecotoxicity assessment. The 48h-L(E)C50 values for seven heavy metals (As, Cd, Cr, Cu, Hg, Ni, and Zn) of D. galeata and D. magna were collected and analyzed. As a results, shorter lifetime, less reproduction, smaller body size of D. galeata were observed compared with D. magna. D. galeata was similar or more sensitive than D. magna for seven heavy metals. Therefore, we propose that D. galeata is a suitable test species for ecotoxicity testing in Korea.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.411-411
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• 2020

하상 변화는 유량이나 유사의 흐름에 따라 침식, 운반, 퇴적되어 변화하며, 하상변동에 의한 결과는 하천의 형태 (직렬,복렬, 곡렬 등)나 서식처의 구조 (여울과 소, 웅덩이, 습지 등) 형성 로 나타난다. 하천이 공간적 시간적 규모가 연계되어 있음에도, 국내에서의 하천 복원 사업은 서식처의 구조나 형태에 중점을 둔 서식처 조성 사업이 주를 이룬다. 하지만 궁극적인 생태하천 복원 및 관리를 위해서는 생태적인 서식처의 구조가 제대로 발현되는 유량이나 유사량과 연계하여, 통합 유역관리가 가능하도록 진행하여야 한다. 본 연구에서는 수리 (유량이나 유사량)-지형(서식처 구조)-생태 (생물다양성)을 연계하여 하천의 환경유량을 산정하는 방안을 제안하고자 한다. Nays2D 수리모델링을 활용하여 하상변화를 살펴보고, 수리모델링 결과를 서식처 구조 분포로 해석하여, 서식처가 다양한 유량을 산정하고 제안한다. 수리모델링 이전에 하천건강성 평가에 활용된 하천 생물종 모니터링 결과와 서식처 다양성과의 관계를 우선 분석하고 수리모델링을 진행한다. 본 연구의 대상 하천은 금강 지류인 갑천 약 5 km를 대상으로 2010년대 생물상, 항공사진, 지형데이타 (DEM and 단면도)를 활용한다.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.217-228
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• 2020

Endophytic fungi were isolated from the leaves of plants inhabiting the Hansando Island in Korea. We identified the fungal strains based on their morphological characteristics and on the phylogenetic analysis using DNA sequences of the internal transcribed spacer, small subunit rDNA, large subunit rDNA, and translation elongation factor 1- α regions. In this study, we isolated five endophytic fungi that have not been recorded in Korea, Arthrinium camelliaesinensis, Beltraniella humicola, B. portoricensis, Microxiphium theae, and Piceomphale pinicola. Their morphological characteristics as well as the results of molecular phylogenetic analysis are reported here.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.779-779
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• 2012

수자원의 개발은 세계적으로 경제, 사회적 발전에 중요한 역할을 해왔으며, 특히 하천은 그 발전의 원동력이 되어 왔다. 하지만 우리나라의 경우, 급속한 산업화와 도시화로 인해 치수에 집중된 개발을 해왔기 때문에, 하천의 환경 생태적 기능은 중요시되지 않아왔다. 최근에서야 하천의 환경적 기능의 제고를 위한 연구의 필요성이 대두되고, 하천생태계의 서식공간을 가능한 한 자연상태로 보전하고자 하는 노력이 늘어나면서, 생태계를 고려한 하천유지유량(생태유량) 산정에 관한 연구가 진행되고 있다. 위와 같이 생태유량을 산정하는 방법으로는 유지유량증분법이 가장 널리 이용되고 있으며, 이를 위해서는 각 어종별 서식처적합도지수를 구축하여야 한다. 이는 수생 서식처 모델링에 사용되는 물리적 인자에 대한 정량적 지수이다. 국내의 경우도, 수계별 어류조사를 수행하고 있으나 대부분이 출현어종분류 및 출현율 등에 국한되어 있어 물리적 인자를 도출하기 어려운 실정이고, 장기간 실측자료의 부족으로 대부분 전문가의 판단에 의존하고 있다. 따라서 이러한 객관적인 서식처 적합도지수의 부재는 생태유량 산정에 있어 큰 어려움을 준다. 본 연구에서는 이런 부족한 국내의 서식처 적합도지수에 객관성을 부여하고, 좀 더 표준화된 방법론을 제시하기 위해 장기간의 현장모니터링 자료를 이용하여 전문가의 주관적인 판단이 배제된 추계학적 방법을 이용한 서식처 적합도 지수를 산정하고, 이를 이용해 적절한 생태유량을 구하는 방법을 제안하고자 한다. 본 연구에서 사용된 자료는 2007-2010년, 'Ecoriver21사업단'의 '생태유량 산정 및 확보기술개발' 과제에서 한국수자원공사가 수행한 현장모니터링 자료이다. 자료 수집 대상지역은 한강과 금강 수계이며 41개 어종에 대한 자료가 수집되었으나 그 중 다른 어종에 비해 상대적으로 많은 현장 데이터가 존재하고, 본 모니터링에서도 한강과 금강 두 수계에서 모두 우점종으로 나타난 피라미를 이용하여 새로운 서식처 적합도 지수 산정 방법의 제안 및 기존 방법에 의한 지수와 비교하였다.

• The Korean Journal of Mycology
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• v.45 no.3
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• pp.229-233
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• 2017

We isolated endophytic fungal strains from roots of Rhododendron schlippenbachii growing in Minjujisan mountain, Korea. The two strains were identified as Engyodontium album and Phaeosphaeria microscopica based on their morphological characteristics and sequence analysis of the internal transcribed spacer (ITS) and large subunit regions of the ribosomal DNA. These two species, E. album and P. microscopica, have not been previously reported in Korea.

• The Korean Journal of Mycology
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• v.21 no.1
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• pp.64-72
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• 1993

Fresh fungi were collected during five field trips to Ullung Island from October of 1989 to September of 1991. Through the observation of some agaric fungi, thirty mushrooms were identified to the species and are listed as below. Among them, three species, Crepidotus geophilus, Mycena elegans, ana Mycena carolinensis were confirmed new to Korea and are registered here with descriptions.

• Korean Journal of Environmental Biology
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• v.33 no.1
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• pp.45-52
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• 2015

Acute toxicity tests for 5 organic solvents were conducted using Euglena agilis carter (E. agilis), a Korean domestic organism. Organic solvents decreased the growth rate of E. agilis in a dose dependent manner. The toxicity to E. agilis was increased in the order of chloroform>acetone${\geq}$ethanol${\geq}$methanol>DMSO based on $EC_{50}$ values from growth test. Organic solvents also induced cell motility and morphological changes of E. agilis. Especially significant effects on the cell swimming velocity, motility, and compactness were observed for chloroform at the concentration of $EC_{50}$ calculated from 96 hr growth test. Overall, toxic responses of E. agilis to test substances are comparable to or more sensitive than D. magna, M. macrocopa and V. fischeri. Our study demonstrates that E. agilis can be a putative ecotoxicity test model organism to assess domestic water quality. Results obtained from this study can be applied to establish the standard test guidelines for ecotoxicity test using E. agilis.

• Korean Journal of Ichthyology
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• v.34 no.3
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• pp.208-217
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• 2022

We wanted to develop a real-time PCR assay capable of detecting Liobagrus obesus in environmental DNA (eDNA) extracted from freshwater samples using a pair of species-specific primers and probe for the endangered fish, L. obesus. The species-specific primers and probe were designed in consideration of single nucleotide polymorphisms between 65 species of freshwater fish living in the Republic of Korea within the cytochrome b (cytb) gene of mitochondrial DNA. The species-specific primers and probe, in the real-time PCR assay, showed high specificity as only the L. obesus genomic DNA (gDNA) was found to be positive in the specificity verification using 65 species gDNA of freshwater fish in the Republic of Korea. In addition, in the detection limit analysis using the serial dilution concentrations of L. obesus gDNA, it was found that it was possible to detect up to 0.2 pg, showing high sensitivity. Afterwards, using the species-specific primers and probe, real-time PCR assay was performed on freshwater samples obtained from 8 stations in the mid-upper basin of Geum River. As a result, the cytb gene of L. obesus was detected in total 5 stations including all 3 stations where this species was collected at the time of field survey. Therefore, the species-specific primers and probe developed in present study, and the real-time PCR assay using them, can accurately detect the cytb gene of L. obesus from eDNA samples, which can be utilized to monitor the existing habitats of this species and to discover potential new habitats.