• ALGAE
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• v.19 no.1
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• pp.69-78
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• 2004

This study was to clarify the variations in a marine ecosystem through examining the species composition of benthic algae in the coast of Dokdo Island during summer (June & August, 2003). The total number of species found in benthic algae was 45 composed of 11% green algae, 29% red algae and 60% brown algae. The dominant species were Enteromorpha linza, Cladophora spp. and Codium frgile for green algae, Ecklonia cave, Eisenia bicyclis, Sargassum confusum, S. patens, S. horneri, Myagropsis myagroides for brown algae and Amphiroa cphedrace. A pusilla, Lithophyllum okamurae, Corallina spp. Laurencia pinnata, L. hamata, Chondria crassicaulit, C. dasyphylla, Gelidium amansii, Neosiphonia yendoi and Polysiphonia yendoi for red algae. The number of benthic algal species decreased more in this study than in previous researches. The whitening of the rocky shore might provoke the decrease of benthic algal biomass and species.

• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.269-273
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• 2014

Coralline algae, the algal whitening phenomenon-causing seaweeds, are characterized by calcareous deposits in the cell wall. The viability of the coralline algae Lithophyllum yessoense and Corallina pilulifera was quantitated using a triphenyltetrazolium chloride assay and eight calcification inhibitors. Among these inhibitors, ferric citrate showed the strongest inhibition of coralline algae viability. The concentrations of ferric citrate conferring 50% inhibition were 1.7 and 3.8 mM for L. yessoense and C. pilulifera, respectively. Thus, at a specific concentration and in a localized area, ferric citrate may be used to prevent the blooming of coralline algae.

• Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.243-246
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• 2005

The addition of seaweed extracts was found to regulate the viability of cultures of the crustose coralline alga Lithophyllum yessoense. The viability was quantitated using a triphenyltetrazolium chloride assay, and the methanol-soluble extracts from 18 prevalent seaweed species were tested. Extracts from Codium fragile and Enteromorpha linza inhibited viability, and a Hizikia fusiform is extract slightly increased viability. The methanol extract of C. fragile, which had the strongest inhibitory activity, decreased viability to 72 or $52\%$ that of the control following addition of 0.2 or 2 mg/mL of extract to the culture, respectively. The main active compound in the C. fragile was lipid. This information is a preliminary result related to the exploration of seaweed restoration in the algal whitening area.

• Journal of Environmental Science International
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• v.25 no.7
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• pp.937-950
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• 2016

Algal blooming in 4 major rivers introduces substantial impacts to water front activity. Concentrations of algae are increasing at major points along the Geum River. Ecosystem food webs can be affected by algal blooming because blue-green algae release toxic materials. Even though there have been many studies on blue-green algae, its causality to environmental factors has not been completely determined yet. This study analyzed the exclusive correlation between various hydrometeorological, water quality, and hydrologic variables and the cell number of cyanobacteria to understand causality of blue-green algae in the Geum River. A prewhitening process was introduced to remove the autocorrelation structure and periodicity, which is useful to evaluate the effective relationship between two time series.

• Journal of Korea Water Resources Association
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• v.49 no.2
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• pp.155-164
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• 2016

Algal blooms not only destroy fish habitats but also diminish biological diversity of ecosystem which results into water quality deterioration of 4 major rivers in South Korea. The relationship between algal bloom and environmental factors had been analyzed through the cross-correlation function between concentration of chlorophyll a and other environmental factors. However, time series of cross-correlations can be affected by the stochastic structure such auto-correlated feature of other controllers. In order to remove external effect in the correlation analysis, the pre-whitening procedure was implemented into the cross correlation analysis. The modeling process is consisted of a series of procedure (e.g., model identification, parameter estimation, and diagnostic checking of selected models). This study provides the exclusive correlation relationship between algae concentration and other environmental factors. The difference between the conventional correlation using raw data and that of pre-whitened series was discussed. The process implemented in this paper is useful not only to identify exclusive environmental variables to model Chl-a concentration but also in further extensive application to configure causality in the environment.

• Journal of Life Science
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• v.23 no.3
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• pp.341-346
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• 2013

The disappearance of seaweed flora in some rocky areas, which is known as algal whitening, barren ground, coralline flats, or deforested areas, is associated with some species of coralline algae. To determine the biological characteristics of a representative species of crustose coralline alga, the 18S rDNA gene was sequenced to identify the genus Lithophyllum. According to its morphological and distributional characteristics, it was deduced to be L. yessoense. Viability was measured using triphenyl tetrazolium chloride and showed high viability from December to February. Culture conditions of $16^{\circ}C$, a 16 hr light, 8 hr dark cycle, and 30 ${\mu}E/m^2/s$ light intensity were optimal for maintaining the viability of the alga for up to five days. Included in the fatty acids was 9.7% ${\omega}$-3 eicosapentaenoic acid. An electron microscopy scan of the surface structure revealed round craters about 3.6 ${\mu}m$ in diameter, which were covered with rough, irregular, and angular polygon-shaped structures about 1.0 to 3.7 ${\mu}m$ in size. Based on the composition and structure found in our study, biomimetic coralline alga might become an environmentally friendly antifouling material against the attachment of soft foulants.