• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.727-743
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• 1996

To know the floristic composition, vortical distribution and community structure of marine benthic algae inhabiting in the intertidal and subtidal zones of Yongil Bay, east coast of Korea, the study has performed using the quadrat method along a transect line from July, 1995 to June, 1996. In this area, a total of 144 species including 2 new red algae to Korea was found: 5 blue-green, 18 green, 20 brown and 101 red algae. The representative species throughout the year were Ulva pertusa, Gelidium amansii and Symphyocladia latiuscula. Dominant species were Sargassum thunbergii in spring, U. pertusa in summer and autumn. In winter, Chondrus ocellatus and Monostroma grevillei occurred dominantly. The standing crop exhibited mean value as $185.8g/m^2$ dry weight. Maximum value was recorded in spring $(267.3g/m^2)$ and minimum was observed in winter $(93.7g/m^2)$. Shannon's species diversity (H') and evenness (J') as maximum value were recorded in spring, whereas minimum values were shown in winter. Vertical distribution, rerognized by cluster analysis based on relative coverage of the species, could be divided into two or three algal groups except spring. In general, green algae (M. grevillei, Capsosiphon fulvescens, U. pefusa, Enteromorpha compressa) and brown algae (Sargassum fulvellum, S. thunbergii) were represented in the upper and middle zone and red algae (G. amansii, C. ocellatus, S. latiuscula, Crateloupia okamurae, Pachymeniopsis eilliptica) in the lower zone. The algal community varied according to season and environmental conditions. Particularly, seasonal variation of vortical distribution seemed to be affected primarily by water temperature. Also seasonal tidal level and tolerance of algal species to desiccation appeared to be associated with it in this area.

• ALGAE
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• v.18 no.4
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• pp.311-320
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• 2003

The community structure of benthic marine algae was investigated at Taean Thermal Power Plant and other places around Taean Peninsula, the west coast of Korea. Total of 100 species including 3 Cyanophyta, 14 Chlorophyta, 18 Phaeophyta, and 65 Rhodophyta were identified. The number of species was highest with 78 species at the Power Plant intake, followed by 61 at the discharge, 56 at Bunjeondo, and 50 at Maoe. It was noteworthy that a subtropical species Caulerpa okamurae was collected at the intake in autumn and it was the first observation in the west coast of Korea. The pattern of vertical algal distribution showed Gloiopeltis furcata occurred in the upper intertidal zone, Sargassum thunbergii and Corallina spp. in the middle and lower zone and Enteromorpha spp. in the lower middle zone. These were all dominant species except for Enteromopha spp., which was subdominant species. Other subdominant species were Chondrus ocellatus and Neorhodomela aculeata. The average diversity indices were between 0.70 and 1.20 at each area based on their dry weight. The similarity index was 0.79 between the algal flora of this study and that of 1987, indicating that the condition of the benthic environment remained unchanged since then. This area maintained its environmental quality, so the algal community remained same with similar structure. This study area seemed a suitable place for long term monitoring of the benthic environment where industrial facilities such as a power plant might affect the benthic algal community.

• Journal of Life Science
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• v.21 no.11
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• pp.1501-1510
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• 2011

In recent years novel potential pharmocological candidates have been looked for in animal, seaweed, sponge, fungi and marine bacteria resources. In this study, matrix metalloproteinases (MMPs) that play an important role in metastasis, arthritis, chronic inflammation and wrinkle formation were used as target enzymes to screen therapeutic agents. The inhibitory effects of several marine algae including green algae (5 species), red algae (18 species) and brown algae (4 species) methanolic extracts on MMPs were investigated in human dermal fibroblasts and human fibrosarcoma cell line (HT1080 cells) using gelatin zymography. In human dermal fibroblasts, the inhibition of MMP-2 was observed in Laurencia okamurae, Polysiphonia japonica, Grateloupia lanceolate and Sinkoraena lancifolia of red algae. In contrast, MMP-2 activation was enhanced in Enteromorpha compressa and E. linza of green algae, and Peltaronia bighamiae and Sargassum thunbergii of brown algae. In human fibrosarcoma cells, MMP-9 activation was decreased in the presence of S. thunbergii of brown algae, Polysiphonia japonica in red algae and E. compressa and E. linza of green algae. The interesting finding is that E. compressa and E. linza of green algae, and S. thunbergii of brown algae exhibited a positive effect on MMP-2 in normal cells, but a negative effect on MMP-9 in cancer cell lines. These results suggest that E. compressa and E. linza of green algae, and S. thunbergii of brown algae contain potential therapeutic ingredients for cancer treatment.

• Food Science and Preservation
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• v.19 no.3
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• pp.455-461
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• 2012

Obesity, a strong risk factor for the development of chronic diseases, is characterized by an increase in the number and size of adipocytes differentiated from precursor cells, preadipocytes. Recent research suggests that increased reactive oxygen species (ROS) production in 3T3-L1 adipocyte facilitates adipocyte differentiation and fat accumulation. This study was to investigate whether reduced ROS production by Sargassum micracanthum extract (SME) could protect the development of obesity through inhibition of adipogenesis. 3T3-L1 preadipocytes were treated SME for up to 8 days following standard induction of differentiation. The extent of differentiation reflected by amount of lipid accumulation and ROS production was determined by Oil red O staining and nitroblue tetrazolium (NBT) assay. Treatment of SME significantly inhibited ROS production and adipocyte differentiation that is depend on down regulation of NADPH oxidase 4 (NOX4), a major ROS generator, and peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) and CCAAT/enhancer-binding protein alpha ($C/EBP{\alpha}$), a key adipogenic transcription factor. These results indicate that SME can inhibit adipogenesis through a reduced ROS level that involves down-regulation of NOX4 expression or via modulation of adipogenic transcription factor.

• ALGAE
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• v.23 no.4
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• pp.335-342
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• 2008

Seasonal and vertical variations of seaweed biomass were examined at Woejodo and Jusamdo of western sea, Korea from July 2006 to April 2007. Annual seaweed biomass was 198.27 g m$^{-2}$ in wet weight at Woejodo and 417.34 g m$^{-2}$ at Jusamdo, respectively and biomass of intertidal zone was greater than that of subtidal zone at Jusamdo sites. Seaweeds distributed vertically from mid intertidal to 5 m of subtidal zone at Woejodo and from high intertidal to 10m of subtidal zone at Jusamdo. Seaweed biomass and species number were maximal at lower intertidal zone (27 species, 365.43 g m$^{-2}$) of Woejodo and at mid intertidal zone (26 species, 684.18 g m$^{-2}$) of Jusamdo. Seasonal biomass varied from 136.73g m$^{-2}$ in autumn to 249.33 g m$^{-2}$ in winter at Woejodo and from 353.37 g m$^{-2}$ in autumn to 482.07 g m$^{-2}$ in summer at Jusamdo. Dominant species was Sargassum thunbergii showing highest annual biomass (Woejodo, 94.68 g m$^{-2}$ Jusamdo, 228.59 g m$^{-2}$) among all seaweeds and finding at various shore levels during the study period. Subdominant species were Corallina pilulifera and Gracilaria textorii at Woejodo, and were Sargassum fusiformis and Chondria crassicaulis at Jusamdo. Thus, we can conclude that Jusamdo shore is better place than Woejodo based on seaweed biomass and vertical distribution, and S. thunbergii is the representative species of the two islands.

• The Korean Journal of Food And Nutrition
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• v.19 no.1
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• pp.8-13
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• 2006

This study was designed to investigate the physicochemical properties of the Sargassum thunbergii, by measuring general composition, minerals, amino acid, free sugar, peroxide value(POV) and thiobarbituric acid reactive substances(TBARS). The contents of crude protein and crude lipid in Sargassum thunbergii were $15.7{\pm}0.8%\;and\;0.9{\pm}0.4%$, respectively. Total content of amino acids was 5,635.5 mg/100 g. The glutamic aid($1,071.3{\pm}1.8mg/100g$) content was the highest, followed by aspartic acid($645.9{\pm}1.4mg/100g$) and phenylalaine ($470.1{\pm}1.4mg/100g$). Galactose and mannose of all free sugar showed the highest values $40.2{\pm}0.5mg/100g\;and\;22.3{\pm}0.4mg/100g$. All solvent extracts of Sargassum thunbergii showed lower POV than ascorbic acid, and chloroform extracts showed the strongest antioxidant activity(4.0 meq/kg) at 12 hours storage. TBARS of chloroform extract were 2.8 mg MDA/L in $FeCl_2$ and 0.9 mg MDA/L in $CuSO_4$ oxygen species.

• ALGAE
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• v.26 no.4
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• pp.333-342
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• 2011

Macroalgae are important primary producers in marine ecosystem. They don't only play an important role as bioindicators but also provide economic resources for humans. Seasonal and vertical variations in seaweed species composition and biomass were examined to determine the ecological status of seaweed beds around Udo, near Jeju Island. We obtained samples at two sites in the high-intertidal to subtidal zones using the quadrat method between June 2010 and May 2011. A total of 262 species were collected, including 31 green, 61 brown, and 170 red algae. The composition of algal species revealed a decrease in species growing in cold water in comparison with the list 20 years ago. The macroalgal mean biomass (g wet wt $m^{-2}$) was 3,476 g and 2,393 g from the two sites, respectively. Ecklonia cava had the greatest biomass at both sites. The seasonal dominant species by biomass at site 1 from the low-intertidal to 1-3 m depth of the subtidal zone was mostly comprised of thick-leathery form, such as Sargassum hemiphyllum, S. coreanum, and Ecklonia cava, whereas site 2 was comprised of the turf form, such as Chondrophycus intermedius, Chondracanthus intermedius, Dictyopteris prolifera, and Gelidium elegans. The current ecological status of the seaweed community in Udo is stable based on diversity and dominance indices.

• Ocean and Polar Research
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• v.25 no.4
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• pp.519-528
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• 2003

Species composition and community structure of marine benthic community were studied in the intertidal zone of Jijindo Island, Gwangyang Bay. A total of 85 species of benthic marine plants including the 5 Cyanophyta, 9 Chlorophyta, 13 Phaeophyta, 56 Rhodophyta and 2 Magnoliophyta that were listed. The community structure was represented by Gelidium divaricatum in the upper zone, Celidium divalicatum and Ulva pertusa in the middle, and Ulva pertusa, Chondria crassicaulis, Chondracanthus intermedia and Sargassum thunbergii in the lower intertidal zone. The dominant species in the rnscro-zoobenthic community were Chthamalux challengeri in the upper and middle, Littorina brevicula between the upper and middle, and Mytilus edulis and Crassostrea gigas in the middle and lower intertidal zones. The economic benthic organisms such as Undaria pinnatifida, Mytilus edulis, and Crassostrea gigas found in the lower intertidal zone were frequently disturbed due to their collection by local resident. Therefore, it is necessary to record the correct information pertaining to these cases. The species diversity indices estimated kom different sources were quite different. They were 2.22 derived from frequency, 1.67 based on coverage, 2.17 based on sum of frequency and coverage and 2.04 derived from importance value. Species diversity and number of algal species in Gwangyang Bay have noticeably decreased, compared with their previously reported status. It is estimated that their decreases were caused by changes in the marine environment, especially pertaining to the polychaete community resulting from reclamation and dredging activity undertaken for the industrial development.

• Journal of Plant Biology
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• v.23 no.2
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• pp.61-67
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• 1980

As a part of the environmental base line survey of the Onsan Industrial Base, Korea, marine algal communities were investigated using the quadrat method in Onsan-myon on the east coast of Korea from March to December of 1978. It was learned that the representative dominat species along the coast in the Onsan area throughout the year are Ulva pertusa, Pachymeniopsis elliptica, and Sargassum thunbergii. Both the number of algal species occurring in the quadrat (50$\times$50cm) and the total coverage were higher in March and September than in June and December. A total of 94 species (1 blue-green, 16 green, 25 brown, and 52 red algae) of marine algae was identified in this study.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.2
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• pp.212-219
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• 2019

This study was conducted to investigate marine algal community characteristics and the status of barren ground in the summer at study sites on Jeju Island, Korea. Sampling was carried out from July to September 2017 using a qualitative and quantitative survey (including coverage of non-geniculated coralline algae and density of grazer) by scuba diving. A total of 121 species were identified, including 11 (9.1 %) green algae, 24 (19.8 %) brown algae, and 86 (71.1 %) red algae. Hyeongjeseom had the greatest diversity, with 60 species, and Harye the least, with 18 species. The mean biomass at the study sites was $1,503.0g{\cdot}m^{-2}$, while the mean for the neighboring islets ($3,268.7g{\cdot}m^{-2}$) was higher than that of the main island ($914.7g{\cdot}m^{-2}$). Also, dominant species was identified: Sargassum macrocarpum at the neighboring islets, and Ecklonia cava at the main island, with differences showing not only in biomass but also species composition. In conclusion, the marine algal community status in summer at the study sites was evaluated based on the algal community characteristics (species composition, biomass, biomass ratio of kelp species), coverage of non-geniculated coralline algae, and density of grazer. As a result, both Hyeongjeseom and Marado require preservation and management to maintain their excellent marine algal communities, and other sites on the main island require the creation and/or restoration of marine algal communities. In addition, as the generation of barren ground accelerates, it is urgent not only to grasp existing monitoring research but also to identify the status of the marine algal community where it is not known at present.