• Journal of Ecology and Environment
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• v.38 no.4
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• pp.619-627
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• 2015

Cyanobacteria were sampled at five sites in the Han River, Nakdong River, and Geum River watershed from June 2014 to May 2015 and then cultivated. Two genera and five species of the cyanobacteria were newly recorded in Korea. The newly recorded species were Limnothrix redekei, Pseudanabaena galeata, Pseudanabaena amphigranulata, Sphaerospermopsis aphanizomenoides, and Calothrix parietina. As a result, the Korean flora of the cyanobacteria now include four orders, 22 families with 73 genera, 143 species, and two varieties, giving a total of 146 taxa.

• Membrane and Water Treatment
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• v.10 no.3
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• pp.191-199
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• 2019

In this study, we investigated the cultivation possibility using Hydrodictyon reticulatum in a continuous raceway pond as a tertiary sewage treatment plant. The cultivation possibility was evaluated by varying the light quantity, wavelength, and hydraulic retention time (HRT). Experimental results showed that the growth rates of algae and the removal efficiencies of nutrients increased as the light quantity increased, and the maximum photosynthetic rate was maintained at $100{\mu}mol/m^2{\cdot}s$ or higher. When wavelength was varied, nutrient removal efficiency and growth rate increased in the following order: green light, red light, white light, and blue light. The nutrient removal efficiencies and algae productivity in HRT 4 d were better than in HRT 8 d. We conclude that if Hydrodictyon reticulatum is cultivated in a raceway pond and used as a tertiary treatment facility in a sewage treatment plant, nutrients can be effectively removed, and production costs can be reduced.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.240-246
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• 2006

Cyanobacteria are present abundantly in rice fields and are important in helping to maintain rice fields fertility through nitrogen fixation. Many rice fields soil contain a high density of cyanobactera, and over 50% of cyanobacterial genera that are in existence in rice paddy fields are heterocystous filamentous forms. A total of 142 isolates of heterocystous filamentous cyanobacteria were screened from 100 soil samples taken from rice paddy fields in 10 different locations across Korea, classified according to their morphological characteristics under light microscopy, and their susceptibly to fungicides examined. The collected blue-green alga were classified into a total of 14 genera, including seven genera of filamentous cyanobacteria and seven genera of nonfilamentous cyanobacteria. In particular, 142 heterocystous filamentous cyanobacteria were isolated and classified into six genera, including Anabaena, Nostoc, Calothrix, Cylindrospermum, Nodularia, Scytomena, and Tolypotrix. Yet, over 90% of the heterocystous filamentous cyanobacteria isolated from the rice paddy fields belonged to two genera: Anabaena and Nostoc. The response of 129 $N_2-fixing$ cyanobacterial isolates, 53 Anabaena and 76 Nostoc, to 10 fungicides was then investigated. The results showed that the Nostoc spp. were more tolerant of the ten tested fungicides than the Anabaena spp., and among the ten tested fungicides, benomyl showed the highest acute toxicity to Anabaena spp. and Nostoc spp. In conclusion, although benomyl is a very useful agent to control phytopathogenic fungi, the application of this fungicide to rice fields should be considered because of its toxicity to the heterocystous filamentous cyanobacteria.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.158-165
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• 1992

A survey on nation-wide distribution of fresh-water algae occurring in paddy rice fields was conducted in 1991. The algae which were collected from the whole nation were classified into a total of 54 genera including 14 genera in the blue-green algae. 29 genera in the green algae, 1 genus in the stoneworts. 3 genera in the euglenoids and 7 genera in the diatoms. The green algae and diatoms occurring in plain regions were diverse in terms of the number of genera distributed, whereas there was no regional difference in diversity of the blue-green algae and the euglenoids. Among the green algae, the suspended unicellular algae such as the genera, Chlamydomonas, Pandorina and Gonium, were widespread in plain regions, but the multicellular algae such as the genera, Spirogyra, Oedogonium, Ulothrix and Hydordictyon, were major in mountainous and attitudinal regions. The filamentous green algae such as the genera. Cladophora and Rhizoclonium, were dominant in reclaimed saline fields. The blue-green algae Oscillatoria spp. and the diatoms Navicula spp. were abundant in soil flakes.

• Korean Journal of Weed Science
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• v.13 no.2
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• pp.96-103
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• 1993

The experiments on the ecological characteristics of the suspensible green algae and the algae causing soil-flakes and shier chemical control were conducted in 1992. The unicellular green algae which were dominated by Chlamydomonas sp. largely occurred when phosphorus was applied, but which were reduced by nitrogen application. The filamentous green algae which were dominated by Klebsormidium sp. largely occurred when phosphorus was applied, and which much more increased when nitrogen or potassium was combined with phosphorus. The suspensible green algae which were dominated by Klebsormidium sp. were controlled by 60-70% when simazine 10g ai/10a and propanil 105g ai/10a were applied. The dark blue soil-flakes largely occurred at nitrogen application, and which much more increased when nitrogen was combined with phosphorus. The dark brown soil-flakes largely occurred at phosphorus application, but no more increased even if nitrogen or potassium was combined with phosphorus. The dark blue soil-flakes which were dominated by Oscillatoria sp. much more increased at the temperature conditions of $18^{\circ}C$ compared with $24^{\circ}C$ and $29^{\circ}C$. The applications of bensulfuron/mefenacet/dymron, piperophos/dimethametryn and bensulfuron/dimepiperate controlled 70-90% of the dark blue soil-flakes.

• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.143-160
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• 2012

The community of periphyton was studied at high altitude streams of the Han-river System, including Buk-stream and Hangae-stream from October to November 2010. The study had special emphasis on the distribution of the cryophilic and mountain periphyton. In this research, 117 taxa of periphyton appeared and 80 taxa of diatom were included within these periphytons. Saproxenous taxa, such as Achnanthes convergens and Hannaea arcus var. subarcus were appeared in most sites, 7 sites were dominant by filamentous taxa in green and blue green algae. The DAIpo value was from 48.8 to 92.5 for the water system of this research. Most sites showed a good water quality, receiving a B class or above except the Woljeong-stream and the Daeki-stream. Cryophilic and mountain periphyton appeared 9 taxa which composed by diatoms Cymbella affinis, Cymbella tumida, Diatoma mesodon, Diatoma vulgare, Eunotia pectinalis, Hannaea arcus, Hannaea arcus var. subarcus and Synedra inaequalis and green algae Ulothrix zonata. Among these taxa, Hannaea arcus var. subarcus, found in 29 out of 33 sites, had the highest frequency of apperance. The relative frequency of Hannaea arcus var. subarcus was positively correlated with altitude($r^2$=0.539) and negatively correlated with water temperature($r^2$=0.338). As a result, Hannaea arcus var. subarcus showed the characteristics of cryophilic and mountain periphyton in the research site.

• Korean Journal of Ecology and Environment
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• v.34 no.2 s.94
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• pp.90-97
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• 2001

The seasonal changes in phytoplankton standing crops, species composition, dominant species, species diversity and physico-chemical characteristics in Woopo and Mokpo swamps were studied from January to December, 1998. Phytoplankton of a total 353 taxa were identified, the composition of phytoplankton community was characetrized by green algae and diatoms and quantity composition of standing crops was dominated by green alga Oscillatoria sp. was especially prominent. The standing crops varied from 108 cells/ml and 118 cells/ml to 19,178 cells and 38,393 cells/ml in Woopo and Mokpo swamps, respectively. The maximum algal density was observed in November, Micractinium pusillum and Oscillatoria sp. usually contributed 83.2% to total cell numbers in Woopo swamp. However, the maximum density occurred in May when Oscillatoria sp. formed bloom in Mokpo swamp. The low species diversity of the phytoplankton coincided with maximum standing crops of the filamentous blue-green alga Oscillatoria sp. and green alga Micractinium pusillum in May and November.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.674-684
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• 2018

The purpose of this study is to construct ecological pond using LID technique in order to create naturally comfortable community space in urban idle space. The specification of the ecological pond is $110m^2$ of surface area, $0.45{\pm}0.02m$ of average depth, and bed material is composed of gravel (diameter ${\leq}60mm$), sand (diameter ${\leq}2mm$) and bentonite. Rainfall and water depth monitoring were conducted to determine the annual characteristics of inflow of the water for the ecological pond, result of total rainfall was 1,287 mm and showed a seasonal imbalance that accounted for 71.3% (918 mm) during July to August, but the annual mean water depth was kept constant at $0.45{\pm}0.02m$ due to the secondary water source. Annual trends of basic water quality showed a significant changes according to the season, such as water temperature ($5.2{\sim}28.8^{\circ}C$), DO (5.0 ~ 13.8 mg/L), EC ($113{\sim}265{\mu}S/cm$). BOD, COD, TN, and TP in physicochemical water quality tended to increase after October, but the ion parameters such as $NH_3$ and $PO_4{^{3-}}$ were generally low. Phytoplankton indicators Chl-a and BGA (blue green algae) showed a sharp increase from July to August, and green algae (Selenastrum bibraianum, Pediastrum boryanum etc.) and filamentous blue green algae (Phormidium sp.) emerged as a dominant species. The ion parameters ($F^-$, $Na^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$) were strongly correlated with the $Cl^-$ as a conservative substance (R=0.70~0.97, p<0.05). Water quality was influenced by the ambient environment such as seasonal changes or rainfall, and it was closely related to fluctuation of the inflow of the water. In the future, it is necessary to consider ecological connections by referring to the characteristics surveyed in this study in order to effectively manage the water quality and biodiversity of the ecological pond in idle space.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.4
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• pp.556-563
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• 2018

Objective: Spirulina has been recognized formerly as a filamentous spiral-shaped blue- green algae but more recently as a genus of photosynthetic bacteria (Arthrospira). This microorganism is considered as a rich source of essential nutrients for human and animals. The present study was conducted to determine potential application of Spirulina for heat- exposed broilers. Methods: Two hundred and fifty Cobb 500 chicks with male to female in equal ratio with average initial weight of 615.6 g at 17 days of age were divided into 5 treatments with 5 replicates of 10 chicks. Treatment groups were as follows: positive and negative controls with 0% Spirulina supplement and three Spirulina receiving groups with 5 g/kg (0.5%), 10 g/kg (1%), and 20 g/kg (2%) supplementation. Spirulina receiving groups as well as positive control were exposed to high ambient temperature at $36^{\circ}C$ for 6 h/d from 38 to 44 days of age. Biochemical variables were measured in serum samples at 35, 38, 42, and 45 days of broiler chickens age. Results: The results showed that supplementation of the diet with Spirulina decreased concentration of stress hormone and some serum lipid parameters while enhanced humoral immunity response and elevated antioxidant status whereas it didn't meaningfully affect performance characteristics. Nevertheless, feed conversion ratio was improved numerically but not statistically in broilers fed with 1% Spirulina under high ambient temperature. Conclusion: Overall, the present study suggests that alleviation of adverse impacts due to high ambient temperature at biochemical level including impaired enzymatic antioxidant system, elevated stress hormone and lipid profile can be approached in broiler chickens through supplementation of the diet with Spirulina platensis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.265-273
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• 1986

The marine algal communities of Yonhwa-do at the southern coast of Korea were investigated in aspects to quantitative analysis of their structure and dynamics. As a result, 114 species, including 2 blue-green, 69 red, 25 brown and 18 green algae, were identified. The R/P value(2.8) is higher than that of other regions of the southern coast of Korea. Sheet and filamentous groups of the functional groups of algae showed higher composition rate in spring and summer than in autumn and winter, but coarsely branched and thick leathery groups showed an opposite tendency. Cluster analysis based on species presence suggested the existence of 5 distinct groups in spring, but 3 groups in the other seasons. The species exhibiting important value above 20 were as follows: Porphyra suborbiculata, Corallina pilulifera, Hizikia fusiforme, Sargassum thunbergii, Undaria pinnatifida, Ishige okamurai, Chondria crassicaulis, and crustose coralline algae. The coverage of algal communities composed only of crustose coralline algal complex was higher than that of other algal complex, but occurrence frequency of these two communities was indifferent. It is suggested that the occurrence in high quantity of crustose coralline algae from this area is related to grazing by herbivorous animals.