• Korean Journal of Ecology and Environment
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• v.36 no.2 s.103
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• pp.150-160
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• 2003

This study was carried out to assess inhibitory effects of light-blocking on water quality and phytoplankton community in Lake Juam from August to November 2000. The values of water temperature, DO, TN, $NO_3-N$, $NH_4-N$, TP, DIP, COD, SS and PH did not show clear differences between inside and outside light-blocked areas. Concentrations of Chl-a decreased -6.6${\sim}$40% (mean 14.7%) from inside of the light-blocked area by light blocking. During the study, 55 species of phytoplankton were indentified, and the dominant species were Microcystis aeruginosa, Aulacoseira granulata, Peridinium sp., Synedra spp., Oscillatoria sp., Fragilaria construens, and Trachelomonas sp. The successional pattern of dominant phytoplankton was diatoms (July)${\to}$ diatoms/cyanophytes (August-September)${\to}$cyanophytes (October)${\to}$ diatoms (October-November). The standing crop of phytoplankton showed maximum density in 22 September with $1.1{\times}10^4$cells/L, and minimum in 25 October with $4.7{\times}10^3$ cells/L. The decreasing efficiency of standing crop by light-blocking was 8${\sim}$38% (mean 19.9%). Through this study we found that blocking light seems to have a decreasing effect on the density of phytoplankton.

• Korean Journal of Ecology and Environment
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• v.41 no.1
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• pp.54-65
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• 2008

The seasonal dynamics of phytoplankton and water quality were evaluated bimonthly at 7 park ponds in the capital region from October 2004 to August 2005. With out the change of water temperature $(0.4\sim26.0^{\circ}C)$, cyanobacteria dominated in park ponds such as Gyungbokgung Gyunghyaeru and Seokchon reservoir. The standing crops of phytoplankton was significant related with cell densities of cyanobacteria (r=0.993), while they did not significant correlation with environmental factors. Almost of all park ponds in the capital region were classified as eutrophic state with high TP concentrations and TN/TP ratios less than 10. Major dominant cyanobacteria were as followed; Anabaena sp., Aphanocapsa elachista, Lyngbya contorta, Merismopedia elegans, Microcystis aeruginosa, M. wesenbergii, Microcystis sp., Oscillatoria sp., Phormidium tenue, and Plectonema sp. To date, although the concentration of chlorophyll-${\alpha}$ and cyanobacterial densities in the capital region was below the 'danger' level of WHO guidelines value, the monitoring of cyanobacterial densities and its toxin (microcystin) in recreational/bath water should be continued.

• Journal of Korean Society on Water Environment
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• v.29 no.3
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• pp.428-437
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• 2013

Physico-chemical water quality parameters and the phytoplankton communities from 12 sites in Oship-stream, Songchunstream, and Namdae-stream, located Gyeongsangbukdo Uljin-gun, Yeongdeok-gun, and Pyeonghae-eup respectively, were investigated from April 2009 to February 2010. Oship-stream, which is an open estuary, was easily affected by ocean current compared to that of Songchun-stream and Namdae-stream. OS3 and OS4 conductivity was higher with a season average of 3,397 ${\mu}s/cm$. The streams were mesotrophic to hypertrophic. Biological oxygen demand (BOD) was about 3mg/L, which was level 2 on the water quality ratings, but a concentration of 5mg/L in April 2009 indicated increased pollution due to drought. A total of 118, 117, and 124 phytoplankton taxa were found in Oship-stream, Songchun-stream, and Namdae-stream, respectively. The apparent dominant species in the polluted waters included Cryptomonas ovata, Fragilaria construens var. venter, Oscillatoria limnetica, O. limosa, and Phormidium tenue. All of Oship-stream, SC2 and SC4 of Songchun-stream, and ND3 of Namdae-stream were eutrophic as a result of standing crop analysis. BOD was highly correlated with chlorophyll-a content(r=0.52). Phosphorus concentration and proliferation of phytoplankton were thought to most affect BOD concentration in all three streams.

• Journal of Microbiology
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• v.37 no.3
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• pp.159-167
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• 1999

The effects of bicarbonate concentration, atmospheric carbon dioxide level, and reduced atmospheric oxygen on biomass and geosmin production and geosmin/biomass (G/B) values for Streptomyces halstedii, a producer of the off-flavor compound geosmin, were determined. In addition, a study was performed to determined possible synergistic relationships between a cyanobacterium, Oscillatoria tenuis UTEX #1566, and S. halstedii in the enhancement of actinomycete growth and/or geosmin production. These studies took into consideration those conditions that can occur during cyanobacterial bloom die-offs. Increasing bicarbonate concentration caused slight decreases in geosmin production and G/B for S. halstedii. Increasing atmospheric oxygen promoted geosmin production and G/B while lower oxygen levels resulted in a decrease in geosmin production and G/B by S. halstedii. Biomass production by S. halstedii was adversely affected by reduced oxygen levels while changes in bicarbonate concentration and atmospheric carbon dioxdie levels had little effect on biomass production. Sonicated cells of O. tenuis UTEX #1566 promoted biomass production by S. halstedii, and O. tenuis culture (cells and extracellular metabolites) and culture supernatnat (extracellular metabolites) each promoted geosmin and G/B yields for S. halstedii. In certain aquatic systems, environmental conditions resulting from cyanobacterial blooms and subsequent bloom die-offs could favor actinomycete growth and off-flavor compound by certain actinomycetes.

• ALGAE
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• v.27 no.4
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• pp.283-294
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• 2012

The physico-chemical and environmental factors of stoneworks were examined from March 2009 to October 2010, and aerial algae living on 24 stoneworks in Korea were identified. Fifty aerial algae were found in 24 stoneworks. Of the 50 taxa, 30 taxa were cyanophytes, 16 taxa were bacillariophytes, 3 taxa were chlorophytes, and 1 taxon was a xanthophyte. Nine species, including Aphanocapsa rivularis, which is known to only live in aquatic conditions, inhabited both aquatic and aerial environments. Synechococcus aeruginosus, Scytonema coactile var. thermalis, S. coactile var. minor, Stigonema ocellatum f. ocellatum, and Oscillatoria boryana were newly recorded in Korea. As a result of a correlation analysis between algae and the physico-chemical and ecological environmental factors, the taxa were divided into the bryophyte group, the humidity group, and the dry group. Although the bryophyte group was included within the humidity group, it was separated from the dry group. Taxa in the bryophyte group including Nostoc commune which was distributed in more humid areas than those in the humidity group. However, dry group taxa including Chroococcus pallidus were distributed in lower humidity than that of the two other groups. Correlations among other environmental factors were tested to identify other factors that could substitute for humidity and light intensity. As a result, tree distance, water distance, and plant coverage were replaceable environmental factors.

• ALGAE
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• v.24 no.4
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• pp.185-193
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• 2009

Geothermal springs in India, formed as a result of volcanic or tectonic activities, are characterized by high temperature and relatively abundant reduced compounds. These thermal springs are inhabited by characteristic thermophilic organisms including cyanobacteria. Cyanobacteria are among the few organisms that can occupy high temperature aquatic environments including hot springs. In alkaline and neutral hot springs and streams flowing from them cyanobacteria can form thick colourful mats that exhibit banding patterns. The present investigation involves study of mat forming cyanobacterial flora from hot springs located in Bakreswar, West Bengal, India. The important species found are Synechococcus bigranulatus, S. lividus, Gloeocapsa gelatinosa, G. muralis, Phormidium laminosum, P. frigidum, Oscillatoria princes, O. fragilis, Lyngbya lutea, Pseudanabaena sp., Calothrix thermalis, and Fischerella thermalis. Their distribution pattern in relation to physico-chemical parameters of spring water has also been studied. Three cyanobacterial strains of the above mentioned list were grown in culture and their pigment content and nitrogen fixing capacity were also studied. Nitrogen fixing capacities of Calothrix thermalis, Nostoc sp. (isolated in culture) and Fischerella thermalis are 5.14, 0.29, and 2.60 n mole $C_2H_4/{\mu}g$ of Chl-${\alpha}$/hr respectively. Carotenoid : Chlorophyll-${\alpha}$ ratio of four mat samples collected from Kharkunda, Suryakunda, Dudhkunda and bathing pool are 2.45, 1.60, 1.48, and 1.34, respectively. Higher value of Carotenoid : Chlorophyll-${\alpha}$ ratio coincided with higher temperature.

• Journal of Environmental Health Sciences
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• v.7 no.2
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• pp.97-105
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• 1981

Water Pollution of Gwangju Stream was examined for four months from 22 March 1981 to 7 June, 1981. For checking the water pollution, 6 sampling positions were selected 5 from main stream. We assumed that the water pollution of Gwangju stream was due to the organic materials, which came from the domestic sewage. The apparatus for this test were pH meter (Orion model 301), Dissolved Oxygen & Temperature meter(Delta model 1010). The results we obtained are as follows: 1. The average range for mid-stream(sp. 3, 4) was 3. 10~2.73ppm of Dissolved Oxygen(DO), 80.23~102.95ppm of Biochemical Oxygen Demand (BOD), 195. 10~165.90ppm of Suspended Solid (SS), 6.6~6.7 of pH. 2. The plankton identification in this survey period showed Cyanophyceae is 4 genera 5 species, Bacillariophycea 11 genera 14 species, Chlorophyceae 8 genera 15 species and Zooplankton 6 genera 7 species: total 29 genera 41 species. 3. To appear dominant plankton in polluted water, there were Paramecium, Euglena and Oscillatoria. 4. The results of biological water analysis were as follows: st. 1 was B-mesosaprobic to oligosaprobic, but st. 4 and st. 5 at stream in the midtown area seemed to be polysaprobic.

• Journal of Environmental Health Sciences
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• v.5 no.1
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• pp.61-65
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• 1978

To investigate the phytoplankton distribution effected by polluted water, this research was carried out at eight sampling places in Tae-jun and one sampling place in Kang-kyong during the period from May 10 to July 25, 1977. The results are as follows. 1) The range of water temperature was 21.0~36.0$\circ$C (May 10~July 25), and pH value was in the range of 3.5~11.0. 2) BOD was generally high (140~432mg/l) 3) At the places where BOD was high, dominant species were Aphanocapsa rivularis, Microcystis aeruginosa and Oscillatoria sp. belonging to Cyanophyta, Chlorella sp. belonging to Chlorophyta, Euglena sp. belonging to Euglenophyta, and Navicula exqua and Navicula sp. belonging to Chrysophyta. 4) At the places where the range of pH value was 3.5~3.8 and the range of BOD value was 134~148mg/l, observable species were Scenedesmus ellipsoideus and Pandorina morurn belonging to Chlorophyta, Navicula exqua belonging to Chrysophyta and Euglena sp. belonging to Euglenophyta. 5) At the places where the range of pH value was 9.0~11.0 and the range of BOD value was 214~220mg/l, a few observable species were Scenedesmus carinatus, Scenedesmus ellipsoideus, Scenedesmus bijuga and Scenedesmus obundance belonging to Chlorophyta.

• Journal of Environmental Science International
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• v.7 no.5
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• pp.607-613
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• 1998

This study was carried out to investigate flora of phytoplankton in Milyang River from July 1996 to April 1997. Phytoplankton were identified 206 kinds and composed of 2 var.-for., 5 forms, 35 varieties, 164 species, 70 genera, 31 families, 14 orders, 6 classes and 5 phyla. According to the seasonal variation, 131 species were founded in summer, 109 species in spring, 108 species in autumn, and 100 species in winter, respectively. Seasonal and stationary variation of standing crops were between 10 and 5.600 cells/mι. At station 7, Cyclotella meneghiniana was bloomed 5,000 cells/mι(89.7%) in winter, and Stephanodiscus hantzschii was bloomed 3,400 cells/mι(74.3%) in spring. The number of species and standing crops were increased with proceeding from upper stream to lower stream. Important species of phytoplankton were 24 species, that are 4 species of Cyanophyta (Aphanocapsa elachista, Merismopedium glaucum, Lyngbya limnetica, Oscillatoria tenuis), 12 species of Crysophyta (Melosira varians, Stephanodiscus hantzschii, Cyclotalla meneghiniana, Fragilaria construens var. venter, Navicula cryptocephala, Cymbella ventricosa, Gomphonema olivaceum), and 8 species of Chlorophyta (Chlamydomonas reinhardi, Eudorina elegans, Pandorina morum, Oocystis borgei, Scenedesmus quadricauda, Microspora crassior). According to the similarity index among the stations, it was generally defind as two water areas such as upper stream(station 1~3) and lower stream(station 4~7).

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.339-345
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• 2011

Although culture techniques for the abalone Haliotis discus hannai are well known, mass culture of the benthic microalgae that are essential live food for the abalone larvae is still not practiced. This study was conducted to identify the microalgal species suitable for the growth of early larvae of H. discus hannai. The growth and attachment rates of 31 microalgal species were examined. Acrylic plates were used as the substrate. Among the 31 microalgal species, nine showing high growth and attachment rates were selected and tested for their dietary values via factors including settlement, metamorphosis, and survival rates of abalone larvae. Tetraselmis hazeni and Rhaphoneis sp. induced the highest settlement rate (65-69%) in abalone larvae. The metamorphosis rate was highest (57%) in larvae fed Rhaphoneis sp. and was also significantly higher in larvae fed Oscillatoria splendida (29%) and T. hazeni (22%) than in those fed other species. The highest survival rate of the larvae during the 15 days after metamorphosis was 67% in those fed Rhaphoneis sp., followed by T. hazeni (42%) and O. splendida (35%). In conclusion, Rhaphoneis sp. is the most suitable diatom for use as a live food for the culture of early larvae of H. discus hannai. In addition, T. hazeni and O. splendida are also potential species to be further developed and utilized in larval culture.