• ALGAE
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• v.23 no.4
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• pp.301-310
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• 2008

The marine benthic algal flora and biomass of Chuja Island, southern coast of Korea, was investigated. The collections of intertidal marine algae were made at two sites, Yecho of Hachujado and Hupo of Sangchujado, from October 2006 to July 2007. A total of 162 species, including 15 green, 47 brown and 100 red algae, were identified in this study. The occurrence of species according to season was abundant during spring to summer and less in autumn. The vertical distribution of intertidal zone in Chujado was characterized by Gloiopeltis spp., Myelophycus simplex, Ishige okamurae, Chondrus ocellatus, Grateloupia elliptica, Hizikia fusiformis and Sargassum spp. The average biomass of macroalgae was measured as 400 g wet wt m$^{-2}$. The dominant species based on the biomass were Sargassum yezoense, S. coreanum and Hizikia fusiformis. ESG II (ecological state group) as an opportunistic species, including sheet form, filamentous form, and coarsely branched form, occurred 85.8% in the intertidal seaweeds. These results provide a baseline for future monitoring studies in the Chuja Island.

• Fisheries and Aquatic Sciences
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• v.13 no.1
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• pp.36-48
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• 2010

An agar-degrading Agarivorans sp. AG17 strain was isolated from the red seaweed Grateloupia filicina collected from Jeju Island. A beta-agarase gene from Agarivorans sp. AG17 was cloned and designated as agrA. agrA has a 2,985 bp coding region encoding 995 amino acids and was classified into the glycoside hydrolase family (GHF)-50. Predicted molecular mass of the mature protein was 105 kDa. His-tagged agrA was overexpressed in Escherichia coli and purified as a fusion protein. The enzyme showed 158.8 unit/mg specific activity (optimum temperature at $65^{\circ}C$ and pH 5.5 in acetate buffer) with unique biochemical properties (high thermal and pH stabilities). Enzyme produced neoagarohexaose, neoagarotetraose and neoagarobiose by degrading agar, and hydrolyzed neoagaro-oligosaccharides were biologically active. Hence the purified enzyme has potential for use in industrial applications such as the development of cosmetics and pharmaceuticals.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.503-508
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• 2009

We investigated species composition and variation of benthic marine algae between 2003 and 2006 at Dokdo on the East Sea. The total number of benthic algae species identified was 96, which included 15 Chlorophyta, 30 Phaeophyta, 50 Rhodophyta and 1 Spermatophyta species. The representative species in this study were Ulva pertusa, Caulerpa okamurae, Codium adhaerens, C. frgile, Undaria pinnatifida, Ecklonia cava, Eisenia bicyclis, Dictyopteris undulata, Padina arborescens, Sargassum horneri, Hildenbrandtia rubra, Lithophyllum okamurae, Amphiroa dilatata, Corallina officinalis, C. pilulifera, Prionitis cornea, Grateloupia elliptica, Plocamium telgairiae, Chondrus ocellatus, Chondracanthus intermedia, Chondria crassicaulis, Polysiphonia morrowii, Melobesioidean algae and Phyllospadix sp. Wet weight biomass according to various depths ranged between 1,094.8 to $2,595.3\;g\;m^{-2}$ during the study period. Mean biomass at the investigated sites was greater in the 15m depth range than in the 5 and 10m depths. Vertical distribution was characterized by Ulva intestinalis, U. linza, Endarachne binghamiae, Bangia atropurpurea, Gloiopeltis furcata and Chondria crassicaulis at intertidal zone, Amphiroa dilatata, Corallina pilulifera, Gelidium amansii, Eisenia bicyclis and Ecklonia cava at 2m depth, Ecklonia cava, Eisenia bicyclis, Padina arborescens, Undaria pinnatifida and Sargasum horneri at 5m depth, Ecklonia cava, Sargassum horneri and Padina arborescens at 10m depth, Ecklonia cava, Myagropsis myagroides, Padina arborescens and Sargassum horneri at 15m depth. The R/P, C/P and (R+C)/P value were 1.67, 0.50 and 2.17, respectively.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.1
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• pp.273-283
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• 2015

This study was carried out to examine the species composition and community structure of benthic marine algae at the subtidal zones of Daepo, Wolpyeong, Wimi and Jigwido in south Jeju, Korea from March to December 2009. Total 87 species including 14 green algae, 23 brown algae, and 50 red algae were collected and identified. Among these species, 9 species were found throughout the year. The dominant species which contributed significantly to the total biomass were Ecklonia cava, Undaria pinnatifida, Peyssonnelia capensis, Cladophora wrightiana, Sargassum serratifolium, Grateloupia angusta, Codium coactum, Plocamium cartilagineum, and Sargassum macrocarpum. The average seaweed biomass was 7,578.2 g wet weight $m^{-2}$ and maximum biomass was recorded seasonally in spring ($9,627.6g\;m^{-2}$), while minimum was recorded in autumn ($5,963.0g\;m^{-2}$), by sites maximum biomass Jigwido ($12,889.9g\;m^{-2}$), while minimum was recorded in Daepo ($5,403.8g\;m^{-2}$). The seasonal and regional flora were investigated as six functional groups. A coarsely branched form was the most dominant functional group constituting from 42.9~52.8% of the total flora. Ecological state group (ESG) II, as an opportunistic species, including sheet form, filamentous form, and coarsely branched form, consisted of 31~59 species, constituting 77.5~84.9%.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.313-320
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• 2011

The oxidative stress level and antioxidant activities in two green algae (Ulva pertusa and Ulva linza), two brown algae (Agarum cribrosum and Dictyota dichotoma), and three red algae (Grateloupia lanceolata, Carpopeltis affinis, and Gracilaria verrucosa) collected from intertidal regions of Korea were assessed. In the two green algae, although the total glutathione content was not as high as that of the brown algae, the glutathione pool was extremely reduced, and the glutathione reductase (GRd)/glutathione peroxidase (GPx) activity ratio was high, which apparently plays an important role for protection against oxidative damage, as manifested by low lipid peroxidation. In the brown algae, which exhibited a low lipid peroxidation level that was comparable to the green algal species, the highest glutathione content, together with high GPx activity, appears to be the most important factor in their antioxidant protection. The red algal species exhibited extremely high lipid peroxidation levels. They also contained the lowest and most oxidized glutathione among the species, as well as the lowest GRd activity. In spite of the marked difference in the glutathione content, the significant difference in the activity of ${\gamma}$-glutamylcysteine ligase, the rate limiting enzyme for glutathione synthesis, among the species was not exhibited. Our results suggest that there is a significant difference in the levels of oxidative stress and antioxidant capacity among the algal species, and that the glutathione system, especially the efficiency of glutathione recycling, plays a vital role in antioxidative protection in algal species.

• ALGAE
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• v.30 no.2
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• pp.139-146
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• 2015

Urchin barrens have been a major issue of rocky coastal ecosystems in temperate regions. In South Korea, the east coast and Jeju Island have especially been a focus because the area of barren ground increases in spite of continual efforts to install artificial reefs. This study approached the urchin barrens issue in South Korea, by focusing on a correlational analysis of urchin and macroalgal abundance. Urchin density and algal species coverage were obtained using a quadrat image analysis. Subtidal sites were then classified into three groups according to the average densities of urchins to evaluate the characterization of the macroalgal community: no urchin (NU) zone; transition (TR) zone, $4inds.\;m^{-2};$ and urchin (UR) zone, ${\geq}8inds.\;m^{-2}$. The average urchin density in the study site was $4.7inds.\;m^{-2}$ and 57 macroalgal species were found in the study site. From the NU zone to UR zone, total species number, species diversity index and evenness gradually decreased, whereas the dominance index increased. The algae species with negative correlations were Grateloupia divaricata, Polysiphonia morrowii, Chondracanthus intermedius, Delesseria violacea, Desmarestia viridis; and those with positive correlations were the crustose corallines, Sargassum horneri. Other species were not significantly correlated with urchin density. The significant correlations indicate that the abundance of some macroalgal species is proportionally regulated by sea urchin density. This study also shows how macroalgal vegetation changes in response to an urchin's density gradient in a natural condition; and there is a TR zone that existed with respect to an intermediate level of algal abundance.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.1
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• pp.54-62
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• 2018

Objective: Due to the threat of global warming, the livestock industry is increasingly interested in exploring how feed additives may reduce anthropogenic greenhouse gas emissions, especially from ruminants. This study investigated the effect of Rhodophyta supplemented bovine diets on in vitro rumen fermentation and rumen microbial diversity. Methods: Cannulated Holstein cows were used as rumen fluid donors. Rumen fluid:buffer (1:2; 15 mL) solution was incubated for up to 72 h in six treatments: a control (timothy hay only), along with substrates containing 5% extracts from five Rhodophyta species (Grateloupia lanceolata [Okamura] Kawaguchi, Hypnea japonica Tanaka, Pterocladia capillacea [Gmelin] Bornet, Chondria crassicaulis Harvey, or Gelidium amansii [Lam.] Lamouroux). Results: Compared with control, Rhodophyta extracts increased cumulative gas production after 24 and 72 h (p = 0.0297 and p = 0.0047). The extracts reduced methane emission at 12 and 24 h (p<0.05). In particular, real-time polymerase chain reaction analysis indicated that at 24 h, ciliate-associated methanogens, Ruminococcus albus and Ruminococcus flavefaciens decreased at 24 h (p = 0.0002, p<0.0001, and p<0.0001), while Fibrobacter succinogenes (F. succinogenes) increased (p = 0.0004). Additionally, Rhodophyta extracts improved acetate concentration at 12 and 24 h (p = 0.0766 and p = 0.0132), as well as acetate/propionate (A/P) ratio at 6 and 12 h (p = 0.0106 and p = 0.0278). Conclusion: Rhodophyta extracts are a viable additive that can improve ruminant growth performance (higher total gas production, lower A/P ratio) and methane abatement (less ciliateassociated methanogens, Ruminococcus albus and Ruminococcus flavefaciens and more F. succinogenes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.927-934
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• 2014

Marine algal flora and community structure were seasonally examined at Jungjado, on the southern coast of Korea, from July 2007 to May 2008. A total of 112 seaweeds, including 15 green, 24 brown, and 73 red algae, were identified and 33 species were found throughout the year. The average seaweed biomass was 145.78 g dry weight $m^{-2}$, and the biomass was maximal in winter (184.74 g) and minimal in autumn (106.17 g). The dominant and subdominant species in terms of biomass were Sargassum thunbergii and Grateloupia elliptica in summer, S. thunbergii and Corallina pilulifera in autumn, S. thunbergii and Chondracanthus intermedius in winter, and Sargassum fusiforme and G. elliptica in spring. The vertical distribution patterns of seaweeds from the upper to lower intertidal zones at Jungjado were S. thunbergii - Ulva conglobata - Gelidium elegans in summer; Caulacantus ustulatus - Chondria crassicaulis - C. pilulifera in autumn; Ulva australis - S. thunbergii - G. elliptica in winter; and Gloiopeltis tenax - S. fusiforme - G. elliptica in spring. Seasonally the evenness, richness, and diversity indices tended to have their highest values during the winter and their lowest values in the summer. However, the dominant index was recorded as lowest in winter and highest in the summer. The C/P, R/P, and (R+C)/P values reflecting the flora characteristics were 0.58, 3.04, and 3.62, respectively.

• Journal of Navigation and Port Research
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• v.30 no.4
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• pp.309-314
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• 2006

Community structure and biodiversity of benthic marine algae were studied in the rocky shore of Phohang New Port, Yeoungil Bay. A total of 79 species of marine algae including 8 Chlorophyta, 23 Phaeophyta and 48 Rhodophyta are listed. The dominant algal species were Corallina pilulifera in all seasons, and Sargassum homeri in winter. Lomentaria catenata, Lomentaria hakodatensis, Grateloupia laceolata, Sargassum thunbergii, Chondria crassicaulis, Ulva pertusa, and Hypnea charoides were subdominant at different seasons. The algal biomass per unit area of the benthic algal community in Pohang New Port under construction was 14506 - 398.93 g dry wt m-2, which means that its annually averaged value is 273.45 g dry wt m-2 . The seasonal change in algal biomass showed highs in winter and spring, and lows in summer and autumn. The algal species diversity (H') based on algal biomass was 2.07 annually in average, with 2.42 in winter, 2.65 in spring, 1.79 in summer and 1.43 in autumn. It was high in winter and spring seasons and low in summer and autumn seasons. It is caused by that spring and winter are the profitable growth time for algae and species components in this study were dominated by the annual or seasonal rather than perennial plants.

• Journal of Plant Biology
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• v.26 no.4
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• pp.181-190
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• 1983

Seasonal occurrence of benthic algae and changes of subtidal vegetation were studied for their species composition, diversity and biomass during 1982 and 1983 at several selected sites at Juckdo Island (38$^{\circ}$12'N, 128$^{\circ}$32'E), eastern coast of Korea. Three large brown algae which played a role in change of algal vegetation through their great biomass were investigated with regard to their seasonal growth. Large brown algae such as Undaria pinnatifida, Costaria costata, Laminaria japonica, Agarum cribrosum, Sargassum confusum and S. hornerii constitute the major portion of vegetation in this area throughout the year. Algal vegetation in spring time is characterized by dominance of species U. pinnatifida and C. costata, whereas the summer vegetation by S. confusum and S. hornerii. In autumn large brown algae are shedded and only small algae, such as Chondrus ocellatus and Grateloupia filicina, remain. The vegetation in winter is dominated by the growth of U. pinnatifida and C. costata. Monthly changes in mean length and weight of randomly collected U. pinnatifida, C. costata and S. confusum are as follows; U. pinnatifida occurs from December to June and shows their maximum growth during March (120 cm in length, 201 g/individual in wet weight), its maximum growth rate is 1.4 cm/day, 3.3 g/day in this month. The growth season of C. costata is very similar to U.pinnatifida, but their average maximum length(110 cm) and weight (106 g/ind.) are lower than U. pinnatifida. The greatest growth rate is during March (1.8 cm/day, 2.0g/day). S. confusum is present throughout the year and reaches the maximum growth (102 cm, 63g/ind.) in July. Maximum growth rate (1.5 cm/day, 1.2 g/day) occurs also during this month. U. pinnatifida and C. costata show different months of maximum growth evidently during the two year. This seems to be caused by a considerable damage to the local vegetation followed by heavy storm in February 1983.