• ALGAE
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• v.24 no.1
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• pp.47-55
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• 2009

Recently, interest in plant-derived food additives has developed natural antioxidants, in order to alternate syn-thetic antioxidants with several disadvantages. In the present study, different organic fractions from solvent parti-tions of 80% methanol extract from Jeju benthic diatoms, Achnanthes longipes, Navicula sp. and Amphora coffeaeformis was assessed for their potential antioxidant effects. Among the solvent fractions tested, n-hexane (80.4%) and 80% methanol extract (76.6%) from A. longipes, chloroform (63.2%) from Navicula sp. and n-hexane (67.4%) from A. cof-feaeformis were effective in DPPH free radical scavenging. Fractions of chloroform (53.4%) and n-hexane (53.1%) from A. longipes exhibited higher activities on $H_2O_2$ scavengin. Fraction of n-Hexane from A. longipes exhibited the highest hydroxyl radical scavenging activity and NO. scavenging activity (56.5% and 75.6%, respectively). Aqueous residue from A. coffeaeformis (75.6%) showed the highest metal chelating effect. chloroform and ethyl acetate frac-tion of all the diatoms exhibited significant antioxidant activities in lipid peroxidation inhibitory activity. In particu-lar, both chloroform and the ethyl ecetate fraction from A. longipes and A. coffeaeformis exhibited lipid peroxidation inhibitory activity significantly higher than that of $\alpha$- tocopherol. These data suggest that the Jeju benthic diatoms tested are rich in hydrophilic and hydrophobic antioxidative compounds with different antioxidative properties that can be applied in food industry.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.4
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• pp.420-425
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• 2003

Species composition, community structure and biodiversity of marine benthic community were studied in the intertidal zone of Seoam, Busan. A total of 75 species of benthic marine plants including 4 Cyanophyta, 6 Chlorophyta, 17 Phaeophyta, 47 Rhodophyta and 1 Magnoliophyta are listed. The dominant marine plants were melobesioidean algae, Chondracanthus tenellus, Sargasium thunbergii, Corallina spp., and Phyllospadix japonica and Ulva pertusa was added in summer. Chthamalus challengeri and Mytilus edulis were dominant zoobenthic species in the upper and middle intertidal zone. The algal species diversity index based on coverage was 1.81; 2.25 from frequency; 2.19 from average of total frequency and coverage, and 1.80 from importance value. The algal diversity indices estimated from different sources were quite different. This means that the index value changes depending on the sources used to calculate the species diversity index, indicating how important it is to select the based data and that it is necessary to standardize the methodology when studying later the algal diversity index. On the other hand, the number of species identified in this study has been found to be reduced by 65% at highest, compared with the result of the investigation that was conducted in the coast of Busan.

• ALGAE
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• v.22 no.1
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• pp.45-52
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• 2007

An intertidal marine benthic algal vegetation and vertical distribution at Kangnung and it’s vicinity, the eastern coast of Korea was investigated to clarify the community structure and vertical distribution by quadrat method. Marine algae identified from the area were 116 species; 15 green, 31 brown and 70 red algae. The dominant species were Ulva pertusa, Codium fragile, Undaria pinnatifida, Dictyota dichotoma, Gelidium amansii, Corallina pilulifera, Carpopeltis affinis, Grateloupia filicina, Pachymeniopsis elliptica and Chondrus ocellatus at study sites. The vertical distribution of intertidal marine algae was divided into three distinct zones. They were characterized by Porphyra tenera at the upper, Enteromorpha spp. and Ulva pertusa at the middle, and Sargassum thunbergii, Hizikia fusiformis and Pachymeniopsis elliptica at the lower zones, respectively. The vertical distribution of subtidal zone algae were characterized by Laminaria spp. at 15m depth and Kjellmaniella crassifolia at 15 to 25 m depths, whereas Agarum cribrosum was dominant at the lower zone than 25 m depth.

• Ocean and Polar Research
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• v.25 no.4
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• pp.569-591
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• 2003

Marine benthic flora was investigated in an Arctic bay. Specimens of chlorophyte, phaeophyte, and rhodophyte were collected and examined over the period from July to August 2003 from Kongsfjorden Spitsbergen in Svalbard Islands. A total of 28 genera and 32 species (5 chlorophytes, 18 phaeophytes, and 9 rhodophytes) was identified and described. A green alga Enteromorpha linza(Linnaeus) J. Agardh, a brown alga Asperococcus compresus Griffiths ex Hooker, and three red algae Gracilaria gracilis (Stackhouse) Steentoft et al., Rhodymenia pacifica Kylin and Schizochlaenion rhodotrichum Wynne et Norris were recorded in Svalbard Islands for the first time.

• ALGAE
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• v.19 no.3
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• pp.257-270
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• 2004

In order to clarify the structure and seasonal dynamics of warm tolerant benthic marine algal community in Korea, the species composition and biomass of marine algae at the discharge canal of Uljin nuclear power plant on the East Coast of Korea were investigated seasonally from February 1992 to October 2000. 107 species of marine algae were found at the discharge canal during the past nine years. In general, the number of species observed was abundant in spring or summer and less in autumn or winter. 27 species (4 blue-green, 5 green, 6 brown and 12 red algae) of marine algae occurred more than 1/ 6 frequency and thus can be categorized as warm tolerant species. Among these, one brown (Dictyota dichotoma) and four red algae (Gelidium amansii, Anphiroa ephedraea, Hydrolithon sargassi, Marginisporum crassissimum) are recorded as warm tolerant marine algae for the first time in Korea. Padina arborescens, Anphiroa zonata and Corallina pilulifera were common species found more than 75% frequency. Seasonal fluctuations of mean biomass were 0-1,330 g dry wt m^(-2) and dominant species in biomass were Corallina pilulifera (contribution to a total biomass proportion 34%), Anphiroa zonata (23%), Padina arborescens (18%) and Sargassum micracanthum (11%). The red algae appeared as predominant algal group at the discharge canal of Uljin nuclear power plant in the qualitative and quantitative aspects. The green algae such as Enterornorpha compressa appeared rather frequently at the discharge canal, but the biomass proportion was very low, in contrast to Kori nuclear power plant where there was definite green algal dominance. Differences in algal communities developed at the discharge canals of Uljin and Kori nuclear power plant on the East Coast of Korea, particularly biomass proportions of green algae, can probably be related to local environmental factors such as water velocity through the canal and natural seawater temperatures.

• ALGAE
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• v.23 no.4
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• pp.317-326
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• 2008

Marine algal flora and community structure were investigated seasonally at three sites in Ilkwang Bay on the southern east coast of Korea from May 2007 to February 2008. Total 103 species including 10 of green algae, 17 of brown algae, 76 of red algae were collected and identified. Among these species, 21 species were found throughout the year. Ulva pertusa, Enteromorpha linza, Grateloupia lanceolata, Chondracanthus intermedia and Caulacanthus ustulatus were distributed dominantly in upper intertidal zone. By contrast, crustose coralline algae, Grateloupia spp., Chondracanthus tenellus, Prionitis cornea and Sargassum spp. occurred predominantly in middle intertidal zone. Grateloupia spp., Sargassum spp., Ecklonia cava and Ulva pertusa were dominant in lower intertidal zone. Annual mean biomass in wet weight was 478.3 g m$^{-2}$. Maximum biomass was recorded in site 1 (731.8 g m$^{-2}$), and minimum was recorded in site 3 (78.5 g m$^{-2}$). The R/P, C/P and (R + C)/P value reflecting flora characteristics were 4.47, 0.59 and 5.06, respectively. Two groups produced by cluster analysis, one including sites 1, 2 and the other including site 3, showed meaningful difference in similarity, each other. Site 3 showed the limited species composition due to inflow of fresh water and absence of solid substratum. However, there was no significant difference between site 1 and site 2. In conclusion, the number of marine algae species and biomass in Ilkwang Bay were markedly reduced comparing with the previous studies. These suggest that a solution for reconstruction of the poor marine algal vegetation is considerably demanded.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.694-703
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• 2012

To understand the characteristics of sedimentary and benthic environments in habitats of naturally-occurring intertidal benthic macroalgae, various geochemical parameters of sediment (grain size, ignition loss [IL], chemical oxygen demand [COD], and acid volatile sulfur [AVS]) and pore water (temperature, salinity, pH, and nutrients) were measured in the southern intertidal zone of Hampyeong Bay at two month intervals from April to October 2009. Ecological characteristics including the distribution and biomass of benthic macroalgae were also investigated. Benthic macroalgae were distributed below 4 to 5 m depth from mean sea level near the lower portion of the intertidal zone where air exposure time is relatively short. The distribution area and biomass of benthic macroalgae gradually decreased during the study period. The surface sediments in the benthic algal region were mainly composed of finer sediments, such as slightly gravelly mud and mud. The temperature, salinity, pH, and nutrient concentrations (except dissolved inorganic nitrogen) in pore water did not differ in regions with and without benthic macroalgae, whereas the mean grain size and the concentrations of IL, COD, and AVS in sediments were much higher in regions harboring benthic macroalgae. The correlation between mean grain size and IL in sediments displayed two distinct gradients and the slope was much steeper in regions harboring benthic macroalgae, indicating that the content of organic matter in benthic algal region is not solely dependent on mean grain size. Our results indicate that the benthic macroalgae in the southern intertidal zone of Hampyeong Bay play an important role in the accumulation of organic matter in sediment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.3
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• pp.179-185
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• 2009

The species composition and distributional patterns in marine benthic algae at intertidal zone in Masan Bay were investigated seasonally throughout 2007. A total of 42 species, 5 Chlorophyta 8 Phaeophyta and 29 Rhodophyta were recorded, and dominant species were Enteromorpha linza, Ulva pertusa, Sargassum thunbergii, Gelidium amansii, G. divaricatum, Corallina pilulifera, Gracilaria textorii, and Polysiphonia morrowii during study periods. Especially the vertical distribution of dominant algal species was remarkable: U. pertusa and G. divaricatum were dominated in the upper part, E. intestinalis, E. linza, S. thunbergii and G. divaricatum were in the middle part, and U. pertusa, Undaria pinnatiffda, S. thunbergii, G. amansii, G. divaricatum and C. pilulifera mainly occurred in the low part of tidal zone. The numbers of species were different with seasons and stations; Higher number of species was 38 species in winter, whereas 28 species were the lowest in fall. The number of species was higher at stations 4 and 6 Mile the lower value was at stations 1 and 2 than other stations. The spatial distributional patterns of marine benthic algal composition at each station in dendrogram and MDS ordination were due to the differences of local topography and physical characteristics such as currents and water movements.

• ALGAE
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• v.22 no.4
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• pp.313-318
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• 2007

Studies have been made of the species composition and community structure of benthic marine algae at intertidal zone and subtidal zone of Youngdo at Busan. In this area, a total of 69 marine algal species including 10 Chlorophyta, 17 Phaeophyta and 42 Rhodophyta was identified. Dominant species in coverage were Enteromorpha linza, Ulva pertusa, Gelidium divaricatum, Hildenbrandtia rubra and Chondrus ocellatus throughout the year. Enteromorpha linza, Ulva pertusa, Porphyra yezoensis, Gelidium divaricatum, Corallina pilulifera, Grateloupia elliptica and Chondrus ocellatus vertically distributed in intertidal zone, while Ecklonia stolonifera, Gelidium amansii, Prionitis cornea, Gracilaria textorii, Acrosorium polyneurum and Phycodrys fimbriata in subtidal zone. The vertical distribution of subtidal zone were characterized by Ecklonia stolonifera at 1 to 5 m depths. During a year, biomass and length of Ecklonia stolonifera gradually decreased from March to January, but increased from February. Zoosporangial sori were observed from September to December. In conclusion, number of species in this area was remarkably reduced as compared to the previous data at Busan and it’s vicinity.

• ALGAE
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• v.32 no.1
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• pp.41-46
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• 2017

In rocky intertidal habitats, abiotic stress due to desiccation and thermal extremes increases with elevation because of tides. A study in Atlantic Canada showed that, at low elevations where conditions are benign due to the brief low tides, fucoid algal canopies (Ascophyllum nodosum and Fucus spp.) do not affect the structure of benthic communities. However, at middle and high elevations, where low tides last longer, fucoid canopies limit abiotic extremes and increase the richness (number of invertebrate and algal species, except fucoids) of benthic communities. Using the data from that study, this paper compares the intensity of facilitation and its importance (relative to all other sources of variation in richness) between middle and high elevations, which represent intermediate and high stress, respectively. Facilitation intensity was calculated as the percent increase in benthic richness between quadrats with low and high canopy cover, while the importance of facilitation was calculated as the percentage of variation in richness explained by canopy cover. Data for 689 quadrats spanning 350 km of coastline were used. Both the intensity and importance of facilitation were greater at middle elevations than at high elevations. As canopies do not affect benthic communities at low elevations, this study suggests that the facilitation-stress relationship at the community level is unimodal for this marine system. Such a pattern was found for some terrestrial systems dominated by canopy-forming plants. Thus, it might be ubiquitous in nature and, as further studies refine it, it might help to predict community-level facilitation depending on environmental stress.