• Asian Journal of Turfgrass Science
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• v.14 no.1
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• pp.257-262
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• 2000

This study was conducted on ten golf courses in the vicinity of Yongin city to find out the kinds of algae and factors affecting algae development on creeping bentgrass greens. 1. Serious algae contamination was observed on almost of creeping bentgrass greens after and before rainy season. 2. There were ten kinds of algae occurred on creeping bentgrass greens, most of which were Oscillatoria spp. (bluegreen algae) 3. The fact that the same kind of algae inhabiting in the pond was observed on greens indicated that greens were easily contaminated by algae in case of greens watered with the pond. 4. This study showed that the main factor affecting algae contamination on greens was not high total nitrogen and phosphorus contents in the green soil, but pond watering.

• ALGAE
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• v.18 no.4
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• pp.355-360
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• 2003

A Gram (-), rod-shaped bacterium in size of 1.6-2.8 $\times$ 0.4 μm was isolated from a eutrophic reservoir, which exhibited growth-inhibiting effect against a bluegreen alga (Anabaena cylindrica). This isolate showed positive reactions for catalase and oxidase, and optimal conditions of 35-40°C and pH 9.0. This isolate was designated AC-1 in this manuscript. In a mixed-culture of A. cylindrica and AC-1, their growth patterns were inversely correlated and the bluegreen algal vegetative cells completely disappeared within 24-36 hours. AC-1 showed similar lytic activity in natural water as in an artificial medium. The lytic activity of AC-1 was dependent on the photosynthetic activity of A. cylindrica. When observed under phase contrast microscope, the isolate lysed vegetative cells of A. cylindrica in scattered state in a liquid medium, whereas heterocysts have not been lysed.

• ALGAE
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• v.20 no.4
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• pp.333-343
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• 2005

Spatial and temporal variations of environmental factors and phytoplankton community were investigated in the three stations of Andong Reservoir in 1997 and 2003. The changes of physico-chemical water quality and phytoplanktonic biomass were higher in 2003 than that of 1997, due to rainfall difference. The concentration of total nitrogen (TN) and total phosphorus (TP) in the reservoir decreased, but total nitrogen fell relatively more between them. TN/TP ratio decreased from 109 to 90 showing no change at the downstream but a big decrease at the midand upstream. Predominant phylum of phytoplankton in Andong Reservoir were six genus that composed to Anabaena, Aphanizomenon and Microcystis of Cyanophyceae, Cosmarium and Scenedesmus of Chlorophyceae and Synedra of Bacillariophyceae, respectively. Among the observed phytoplankton, diatom Synedra occured as the maximum amount of 3,400 cells mL$^{-1}$ even at the above 30°C. Green algae Scenedesmus observed along with Microcystis. It seemed to be compete with Microcystis during the high water temperature period. Although trophic state of Andong Reservoir was decreased, the standing crops of phytoplankton were increased. Moreover bluegreen algae, Aphanizomenon and Microcystis in the region of upstream to midstream and diatom, Synedra in the region of midstream to downstream were increased until to reach the algal bloom, respectively. It seemed necessary to attention the changes of blue-green algae Aphanizomenon, that has an ability of nitrogen fixation.

• Korean Journal of Ecology and Environment
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• v.40 no.3
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• pp.431-438
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• 2007

This study was to test algal removal efficiency by top-down fish biomanipulation experiments in the laboratory during Agust${\sim}$September 2000. We selected eight candidate fishes for the biomanipulation. We set up the experiments of eight fish-treatment tanks (3${\sim}$6 fishes) with initial chlorophyll-${\alpha}$ concentrations (CHL-${\alpha}$) of $100{\sim}120{\mu}g\;L^{-1}$ and one control tank including no fish with the same initial CHL-${\alpha}$. All tanks were maintained water quality of dissolved oxygen $(5.3{\sim}8.2mg\;L^{-1})$ and pH $(7.4{\sim}8.1)$ in the tests. During the biomanipulation, DO and pH in the treatments were lower than those of the control, while conductivity increased gradually in the treatments. Biomanipulation experiments showed that CHL-${\alpha}$ increased 13% and 0% (mean values of 8 fishes) in the controls and treatments, respectively. These results indicate that algal growth was maintained in the control and fish treatments, but the rate of CHL-${\alpha}$ in the treatments was lower than that of the control. The removal rates of bluegreens algae decreased 32% in the control, and 20% in treatments (mean values of 8 fishes) respectively, In other words, bluegreen algae showed greater growth rate in the fish treatments than the control and this was due to higher nutrients supplied from fish excretions. Overall, simple fish biomanipulation on algal control was not effective at all in these laboratory tests.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.11
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• pp.780-785
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• 2012

Existing states of attached algae in the sedimentation basin was observed during late april to early october, and the attached algae were visible 7 days after of cleaning the trough and the communities of algae became larger with increasing the operation periods. Attached algae community included bluegreen algae (Oscillatoria sp.), diatom (Synedra sp.,) and green algae (Mougeotia sp., Oedogonium sp.) and suspended diatom (Stephanodiscus sp.) as well. Diatom (Cymbella sp., Navicula sp., Synedra sp. and Stephanodiscus sp.), green algae(Mougeotia sp. and Cosmarium sp.) and blue-green algae (Anabaena sp.) were detected in the effluent of sedimentation basin. The chlorophyll-a (chl-a)concentrations of algae community on a square centimeter after 14 and 28 days were distinctively different depended on the copper sulphate treatment. The concentration of chl-a were $4{\mu}g/L/cm^2$ and $19{\mu}g/L/cm^2$ for the copper sulphate treated water and $59{\mu}g/L/cm^2$ and $147{\mu}g/L/cm^2$ for the untreated water. Diatom algae fragments were observed in red-brownish sediments on the bottom of industrial water distribution basin and degraded blue-green and green algae formated organic sediments combined with oxidized iron.

• Korean Journal of Ecology and Environment
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• v.33 no.1 s.89
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• pp.38-50
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• 2000

Seasonal changes of the phytoplankton and the periphyton community were investigated from August 1998 to April 1999 at five stations at the Suer stream in Kwangyang. A total of 112 species of phytoplankton were identified. Of those, the diatoms were present at all stations but the green algae, the bluegreen algae, and the dioflagellates were present at Station 4 and Station 5 more frequently than the other stations. The phytoplankton standing crops varied from 10,100 cells/1 at Station 4 in April 1999 to 1,489,100 cells/1 at Station 4 in October 1998. The seasonal variation patterns of phytoplankton standing crops were different among stations as well as the pattern of presence. The dominant species were as follows: Achnanthes minutissima, Aulacoseira distans v. alpigena, Cocconeis placentula v. lineata, Cymbella minuta, C. silesiaca, Fragilaria arcus v. recta, Peridinium cinctum, Rhizosofenia longiseta, Synedra rumpens and filamentous algae. Of those, Achnanthes minutissima, Rhizosolenia longiseta, Synedra rumpens and filamentous algae showed the highest rate of occupation in the phytoplankton standing crops during the investigated periods. A total of 99 species of periphyton were identified. Among those, the diatoms of the periphyton community were observed frequently rather than those of the phytoplankton community. The ecological indicator values showed ${\bate}$-mesosaprobous in saprobity and was close to eutraphentic in trophic state. There were no considerable differences between the ecological indicator values by planktonic diatoms and periphytic diatoms.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.320-333
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• 2016

This study was carried out to elucidate the development of unprecedented water-bloom caused by a single species of colonial green algae Eudorina elegans in the upstream area of the Seungchon weir located in the Yeongsan River from late April to May 2013. The Yeongsan River is typically regulated system and the waterbody is seriously enriched by both external and internal sources of nutrients. Seasonal algal outbreaks were highly probable due to various potential factors, such as the excessive nutrients contained in treated wastewater, slow current, high irradiation and temperature, in diatom (winter), green algae (spring) and bluegreen algae (summer). Spring green-tide was attributed to E. elegans with level up to $1,000mg\;m^{-3}$(>$50{\times}10^4cells\;mL^{-1}$). The bloom was exploded in the initial period of the algal development and after then gradually diminished with transporting to the downstream by the intermittent rainfall, resulting in rapid expansion of the distribution range. Although the pulsed-flows by the weir manipulation was applied to control algal bloom, they were not the countermeasures to solve the underlying problem, but rather there still was a remaining problem related to the impact of pulsed-flows on the downstream. The green-tide of E. elegans in this particular region of the Yeongsan River revealed the blooming characteristics of a colonial motile microalga, and fate of vanishing away by the succeeding episodic events of mesoscale rainfall. We believe that the results of the present study contribute to limno-ecological understanding of the green-tide caused by blue-green algae in the four major rivers, Korea.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1333-1337
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• 2006

표층수를 주요 취수원으로 활용하는 우리나라의 경우 저수지 내 남조류 대발생시 주로 인공순환에 의한 제어방안을 적용하고 있다. 본 연구에서는 간헐식 폭기장치를 사용중에 있는 H호를 대상으로 식물플랑크톤 제어 효과를 평가하고, 이에 따른 식물플랑크톤의 수직적 분포와 선택 취수와의 연관성을 규명하여 정수장 유입 원수의 수질을 향상하고자 하였다. 2005년 H호의 남조류 농도는 최대 $1.2mg/m^3 $ 수준으로 낮은 분포로 조사되었다. 남조강에 대한 폭기 효과는 6월에는 워낙 그 농도가 낮아 효과 분석 자체가 무의미 하였으나, 10월에는 비영향지점 보다 영향지점의 최대 농도가 약 28% 저감되는 효과를 확인하였다. 조사 기간 중 가장 높은 농도를 보인 조류강은 Cryptophyta이었으며 6월9일에 약 $5mg/m^3$ 농도로 측정되었다. 10월6일에는 Diatom, Bluegreen, Green algae, Cryptophyta가 비슷한 농도 분포로 혼재된 양상을 보였다. 다른 조류강의 경우 조사 기간 중 $3mg/m^3$ 이하의 농도로 측정되었다. 취수탑을 중심으로 설치하여 운영하는 간헐식 폭기장치 1기의 유효 영향 범위를 조사하기 위하여 폭기 영향권에서 식물플랑크톤 분포를 submersible fluorescence probe로 현장에서 실시간으로 조사한 결과 식물플랑크톤 밀도는 감소하고 수직적인 분포층은 깊어지는 현상을 보였다. 이러한 효과를 보이는 거리는 폭기 장치로부터 약 50m로 나타났으며 pH, DO, 수온항목의 결과에서도 같은 현상을 보였다. 이 결과에 따르면 현재 설치된 총 7기의 폭기 장치의 유효영향 범위는 최대 $0.07km^2$ 면적에 그 효과를 기대할 수 있을 것으로 판단되어, 남조 수화현상이 심화될 경우 인공순환에 의한 저감효과가 크지는 않을 것으로 예측된다. 조사 기간중 H호의 현존 식물플랑크톤량의 $60%{\sim}87%$가 수심 10m 이내에 분포하였고, 녹조강과 남조강이 우점하는 하절기에는 5m 이내에 주로 분포하였다. 취수탑 지점의 수심이 연중 $25{\sim}35m$를 유지하는 H호의 경우 간헐식 폭기장치를 가동하는 기간은 물론 그 외 기간에도 취수구의 심도를 표층 10m 이하로 유지 할 경우 전체 조류 유입량을 60% 이상 저감할 수 있을 것으로 조사되었다.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.70-75
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• 1986

The population and kinds of algae causing the waterbloom on the rice seedling bed and the damage of young rice plant by the nuisance green phytoplanktonic algae in rice field were studied to find out the efficiency of fertilizers and the effect of methods of fertilizers application in the rice field, laboratory, pot and green house. pot and green house. The results obtained were summarized as follows; 1. In the rice seedling bed, the kinds of algae causing waterblooms were identified mainly photosynthetic bluegreen algae as the Anabaena, Ulothrix and Oscillatoria spp. in reclaimed saline soil. Micromonospora, Oscillatoria, and Chlamydomonas spp. were habitated mainly in plain. Whereas, Spyrogyra, Oscillatoria and Navicula spp. were identified mainly in mauntainous area. 2. In the rice field, the nuisance phytoplanktonic green algae were identified mainly Scenedesmus, Chlamidospora, and Micromonospora spp. in Gimjae plain, in Namweon mountainous area and Gangjin costal plain, respectively. 3. The algal biomass has been havily habitated in which rice field were constituted with high pH value and high concentration of $NH^+_4-N$ and $NO^-_3-N$ in surface water and in soil with the optimum temperature for the algal growth ($22-30^{\circ}C$). 4. In the laboratory experiment, maximum algal biomass were obtained at levels of 80 ppm for the nitrogen and 20 ppm for the phosphorus. And were obtained of the levels of 40 ppm in the case of joint application of N and $P_2O_5$. 5. From the pot experiment, compare of the control plot, an addition of nitrogen alone or nitrogen+phosphorus enhanced algal biomass while the phosphorus alone did not. 6. Surface application of fertilizer was remarkably increased of algal biomass than did the whole layer or deep layer application.