• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.276-283
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• 2009

Enrichment in nutrients coming from urban sewage outfalls can lead to eutrophication in coastal areas, which can also change the species composition and community structure of macro algal communities. We investigated the structure of the macro algal community within three rocky shores in order to assess any possible differences in their characteristics. Site 1 was located near Tongyeong city's sewage outfall, Site 2 was located near a public beach area, and Site 3 faced open channel of the Ocean. All three sites were located within the same stretch of the coast, where Site 2 was located between sites 1 and 3. We measured the nutrient concentration in water and the tissue nitrogen content in macro algae samples. Nutrients in the water column surrounding site 1 were high in ammonium ($30.2\pm1.8{\mu}M$), nitrate ($26.2{\pm}0.1{\mu}M$), and phosphate ($2.7{\pm}0.1{\mu}M$) content, and were characterized by low numbers of macroalgal species and species and a low species diversity index. In contrast, site 3 exhibited relatively low nutrient concentration levels and a high number of macroalgal species and a high species diversity index. Comparative analysis showed that the tissue nitrogen content of macroalgae were significantly (P<0.05) affected by the nutrient concentration in the water column. The tissue nitrogen content of green algae within site 1 was higher than the others sites. However, the tissue nitrogen content of brown algae was similar at all three sites. Thus, the tissue nitrogen content of macro algae and the macro algal community structure of intertidal rocky shores were dependent on location and the performance of macroalgal communities was dependent on water quality.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.3
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• pp.262-270
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• 2012

Seaweeds provide habitats in which marine animals can spawn and develop, and serve as a food supply for algaegrazing species such as sea urchins and abalone. Recently, seaweed species have disappeared from coastal ecosystems, leaving barren ground, defined as habitats that have lost their algae forests and where coralline algae containing calcium carbonate components have become encrusted on rocks. The biological causes of barren ground include grazing by herbivores and excessive seaweed harvest. The environmental harm caused by the spread of barren ground includes accelerated eutrophication following the reduction in seaweed, which plays an important role in oceanic purification. In the present study, we identified the relationships between various seaweed species and the occurrence of barren ground. Subtidal benthic macroalgal flora and community structure were observed seasonally on barren ground along vertical transects of rocky shores of Bihwa, Samchuck, and the east coast of Korea from February to November 2006. Fifty-eight seaweed species were identified, including 7 green, 15 brown, and 36 red algae species. There were between 6 and 28 species among seasons. Over the whole study period, average seaweed biomass (g wet wt $m^{-2}$) was 241.90 g, with a seasonal range of 25.26 to 760.34 g. Seaweed biomass declined with increasing seawater depth and ranged between 91.26 and 422.08 g. The vertical distribution of algae was characterized by Undaria pinnatifida and Sargassum honeri at 5 m, S. honeri and U. pinnatifida at 10 m, and U. pinnatifida and Agarum clathratum at 15 m depth. Seasonal patterns in community indices were not found. Community indices showed different patterns along vertical shoreline gradients; the dominance index increased but the richness, evenness, and diversity indices decreased with seawater depth. Sea urchin density was 8 to 24 individ. $m^{-2}$ in Bihwa. These urchin populations had significantly aggregated spatial patterns and recurrent destructive grazing appeared to be occurring.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.3
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• pp.191-201
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• 2014

Marine algal flora and community structure were investigated seasonally at three sites in subtidal zone of Wangdol-cho on the east coast of Korea from May 2012 to August 2013. A total of 122 species were collected and identified, including 12 green algae, 29 brown algae, and 81 red algae. Of these, 38 species were found throughout the survey period. Average seaweed biomass was 472.19-1,198.77 g wet wt. $m^{-2}$ in spring, 68.99-631.14 g wet wt. $m^{-2}$ in summer, 200.91-401.20 g wet wt. $m^{-2}$ in autumn, and 53.61-922.32 g wet wt. $m^{-2}$ in winter. The vertical distribution based on biomass were Grateloupia lanceolata, Acrosorium venulosum, Lomentaria catenata - Undaria pinnatifida, Dictyopteris pacifica, Sargassum horneri, Ecklonia cava - Desmarestia viridis, E. cava, S. horneri from upper to lower subtidal zone. The flora was classified into six functional groups: filamentous form (34.43%), coarsely branched form (25.41%), sheet form (24.59%), thick leather form (9.71%), crustose form (5.74%) and jointed calcareous form (0.82%). The C/P, R/P and (R+C)/P values reflecting the flora characteristics were 0.41, 2.79 and 3.21, respectively. Also, diversity index (H') and dominance index (DI) indicate that the algal community and environmental condition of Wangdol-cho is stable. We recommend that Wangdol-cho subtidal zone should be more protected from human activities such as turbulence and eutrophication in order to maintain species diversity and abundance of algae.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.109-114
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• 2006

For the purpose of oligosaccharide production from alginate, the main component in cell walls of brown algae, the alginate degrading bacteria have been screened from the seaweeds and soil. Among the isolated 69 strains, one strain showing the highest degrading activity was selected and identified as Bacillus licheniformis strain. The adequate sodium alginate concentration for growing the Bacillus licheniformis was $2.0\%$. The effective nitrogen source is nutrient broth $(0.1\%)$, and optimum initial pH, NaCl concentration, temperature and incubation time to produce the alginate degrading enzyme were 7.5, $2\%,\;30{\pm}2^{\circ}C$, and 144 hrs, respectively.

• Journal of Plant Biology
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• v.29 no.3
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• pp.175-183
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• 1986

Marine algal flora and intertidal vegetation around Samchonpo power plant, south coast of Korea, were investigated at three sites, specially referred to the seasonal variation of the species from April to October, 1982. A total of 84 species were identified; 8 green, 19 brown and 57 red algae. Among three sampling sites investigated, 65 species were collected at the first site located in front of the power plant, 66 at the second site, Namildae beach, and 61 at the third, Sinsudo, respectively. The algal vegetation at the first site was dominated in cover by Sargassum thunbergii and Ulva pertusa in April, Corallina spp. Ulva pertusa in July, and Chondria crassicaulis and Ulva pertusa in October. At the second site, it was dominated in cover by Sargassum thunbergii, Gigartina tenella and Ulva pertusa in April, Sargassum thunbergii and Ulva pertusa in July, and Chondria crassicaulis and Ulva pertusa in October, whereas at the third site Sargassum thunbergii and Ulva pertusa in April, and Chondria crassicaulis in October, respectively. The biomass among three investigated sites showed 2,360 g-fresh wt/$m^2$ on an average; 283 g-dry wt/$m^2$ at the first, 277 g-dry wt/$m^2$ at the second, and 256 g-dry wt/$m^2$ at the third site, respectively.

• Journal of Marine Bioscience and Biotechnology
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• v.14 no.2
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• pp.93-101
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• 2022

Hizikia fusiforme, a type of brown algae, is widely used in Asian cuisine. It has been reported to have various pharmacological effects. In this study, the effects of the ethanol extract from H. fusiforme (EAHF) on the proliferation of human colon carcinoma cells were investigated. The effect on the survival of human hepatocarcinoma and colon carcinoma cells was examined, and results revealed that the anti-proliferative effects of EAHF were higher in colon carcinoma cells than in hepatocarcinoma cells. The inhibition of proliferation of HT29 colon carcinoma cells by EAHF treatment was closely related to the induction of apoptosis. EAHF treatment also increased caspase activity and poly(ADP-ribose) polymerase degradation, induced mitochondrial dysfunction, altered Bcl-2 family protein expression, and increased the rate of cytochrome c released from the mitochondria into the cytoplasm. Furthermore, the production of reactive oxygen species (ROS) was markedly stimulated by EAHF treatment, and when ROS production was blocked, EAHF-induced cytotoxicity was significantly attenuated. These results indicate that the anticancer activity of EAHF in HT29 colon carcinoma cells was induced by ROS-dependent mitochondrial impairment. While EAHF exhibited potent anticancer activity in colon carcinoma cells in this study, further studies on the active components of EAHF and their efficacy should be performed.

• Journal of Marine Bioscience and Biotechnology
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• v.15 no.1
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• pp.24-32
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• 2023

The Laminaria japonica Aresch (Sea tangle) belongs to the brown algae and has a long history as a food material in Asia, including Korea. Recent studies have found that the fermented Sea tangle extract (FST) inhibited the differentiation of osteoclasts and protected osteoblasts from oxidative damage. This study aims to explore the possibility that FST can induce the differentiation of osteoblasts and identify the responsible mechanism. According to our results, FST induced differentiation into osteogenic cells in the presence of osteoblastic MC3T3-E1 cells under non-toxic conditions.. This finding was confirmed by phalloidin staining, increased alkaline phosphatase activity, and calcium deposition. Additionally, it was found that this process was achieved by increasing the expression of key factors involved in osteoblast differentiation, such as runt-related transcription factor-2, osterix, β-catenin, and bone morphogenetic protein-2. Moreover, FST increased autophagy, which may contribute to the maintenance of the bone formation homeostasis, and is associated with the activation of the phosphatidylinositol 3-kinase/Akt and mitogen-activated protein kinase signaling pathways. Although further research about the bioactive substances contained in FST and the tests of their efficacy are required, the results of this study indicate that FST has incredible applicability as a functional material for maintaining the bone homeostasis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.768-775
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• 2015

Seasonal variability in the marine seaweed community structure was examined in the intertidal zones at nine study sites in Hallyeohaesang National Park, on the southern coast of Korea from March to October 2014. A total of 145 seaweeds were indentified, comprising 15 green, 41 brown and 89 red algae. Coarsely branched seaweeds were the dominant functional group, comprising 58.95% in species number, whereas filamentous, sheet, thick leathery, crustose and jointed calcareous forms comprised 2.63-17.72% each. The seaweed biomass averaged 358.00 g dry wt/m² and it was maximal at Somaemuldo (847.64 g dry wt/m²) and minimal at Gamam (56.51 g dry wt/m²). Based on biomass, the dominant and subdominant seaweeds were Ulva australis at Gamam, Sargassum thunbergii at Sangju, Ulva australis and S.fulvellum at Neukdo, S.horneri at Dala-Bijindo-Somaemuldo, S. thunbergii at Dapo, and Corallina pilulifera at Songdo. Community indices were as follows: dominance index (DI), 0.43-0.71; richness index (R), 8.26-16.50; evenness index (J'), 0.36-0.54; and diversity index (H'), 1.57-2.19. In conclusion, we found that both biomass and the community structure of seaweeds in Hallyeohaesang National Park were similar to those in other studies of the Southern Sea along the Korean peninsula, and that Hallyeohaesang National Park is a relatively favorable habitat for seaweeds. Future studies should examine the changes in seaweed composition and biomass as they relate to climate change and environmental pollution.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.2
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• pp.86-93
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• 2007

Chronic inflammation has been known to have a close relationship with several diseases including periodontitis, colitis, hepatitis and arthritis. Recently anti-inflammatory agents have been developed from marine natural resources. In this study, Ecklonia cava (EC) was found to have anti-inflammatory effect. Ethanolic extract of EC belonging to brown algae exhibited an excellent inhibitory effect on the production of inflammatory mediators such as tumor necrosis factor-${\alpha}$, interleukin-$1{\beta}$, interleukin-6 and prostaglandin $E_2$ by RA W264.7 cells. Furthermore, in reporter gene assay and western blot analysis, EC extract exerted anti-inflammatory effect via inactivation of NF-${\kappa}B$ transcription factor that regulates the expression of these inflammatory mediators in macrophages. In addition, EC extract inhibited the activity of matrix metalloproteinase that play an important role in chronic inflammation. These results suggest that EC extract may provide a pharmaceutical potential in inhibiting chronic inflammation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.4
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• pp.210-219
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• 2007

The benthic marine algal flora and community structure were examined at five sites of the Taean Peninsula, Korea, during July-August 2005. Ninety-six algal species were Identified, including 14 green, 21 brown, and 60 red algae, and 1 marine plant. The common species that occurred at the five sites were Sargassum thunbergii, Gelidium divaricatum, Caulacanthus okamurae, Gracilavia vermiculophylla, and Neorhodomela aculeata. Sthunbergii was the dominant species in terms of coverage and biomass at ail of the study sites. The average biomass varied from $23.72g/m^2$ in dry weight at Chaeseokpo to $66.43g/m^2$ at Padori. The species could be divided into six functional groups in terms of morphological characteristics: 41 coarsely branched forms, 25 filamentous forms, 16 sheet forms, 7 thick leathery forms, including the marine plant Phyllospadix iwatensis, 4 crustose forms, and 3 Jointed calcareous forms. The seaweed communities at the five study sites were unstable and the environmental conditions were bad or very bad. Among the five study sites, the ecological evaluation index (EEI) and diversity index (H') were maximal at Padori at 2.29 and 1.98, respectively. By contrast, the dominance index (DI) was minimal at Padori (0.55) and maximal at Baramarae (0.96). Therefore, we conclude that the rocky shore at Padori has the best environment among the five study sites, although the species richness and biomass of seaweeds have declined continuously over the last 10 years.