• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3206-3210
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• 2013

This study focused on the matrix interference for the qualitative and quantitative analysis of inorganic arsenic species in seaweed by ion chromatography (IC) combined with inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The matrix of seaweed has a significant effect on the determination of inorganic arsenic species. In particular, the retention times of inorganic arsenic species in the in the standard solution were different from those in seaweed because of the matrix interference. Thus, it was not suitable to use the chromatographic method for the determination of the arsenic species in seaweed. We investigated an alternative method for the determination of inorganic arsenic species in seaweed. The method was applied for the seaweed samples such as laver, green laver, sea tangle and sea mustard. The sample extraction methods of the arsenic species were also investigated in this study.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.6
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• pp.1336-1347
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• 2013

The marine algal flora assemblages settled on the artificial seaweed reefs in Jeju-do before and after rocky cleaning were investigated during summer and the early succession of seaweeds attached to the test panels on the structures of the artificial reef after rocky cleaning were observed by visual observations and under the dissecting microscope in order to evaluate the effects of this rocky cleaning operation. Species composition and algal biomass on the Bboolsamgak-typed seaweed artificial reefs before and after rocky cleaning were measured and compared before and after rocky cleaning. Before rocky cleaning in July 2012, only nine algal species had existed on the Bboolsamgak-typed seaweed artificial reefs, however, twenty algal species occurred on the seaweed artificial reefs after rocky cleaning in July 2013. Particularly, 15 species among them in July 2013 were not found in July 2012 and they seemed to occur newly on the artificial reefs. A large quantity of algal biomass increased in July 2013 after rocky cleaning. Based on the importance value, there was a drastic change in the dominant species between July 2012 and July 2013 after rocky cleaning. By dissecting micrographs, an epiphytic diatom, Licmophora sp. and flagellates, were observed on the 9th day. A chlorophyte, Ulothrix flacca was observed after 14 days, Ulva pertusa, Bryopsis pulmosa, crustose coralline algae, and Cladophora spp. were after one month. After two months, a significant species succession was observed from three previous chlorophyte species to crustose coralline algae existed as a dominant species on the panels. In this study, however, any brown algae were not found until three months in the early seaweed succession. All above results indicates that the rocky cleaning is a very efficient method for the establishment of macroalgal assemblages on the artificial reefs.

• KSBB Journal
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• v.26 no.4
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• pp.267-276
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• 2011

There is a growing worldwide interest in the potential of marine biomass as an environmentally friendly and economically sustainable resource. Due to the great lack of comprehensive information about domestic seaweed resources, this study aimed to analyze the existing literature on the production and types of domestic seaweed species. Based on this data the possibilities of industrial use of domestic seaweed for the production of biofuels and bioplastics had been assessed. Our review took into account the seaweed species on domestic coasts as well as the species currently in great production via seaweed farming. Due to their wide distribution, their status as farmed crops, and the likelihood of securing their reliable supply, Codium fragile, Hizikia fuciformis, and Gelidium amansii were deemed to be the most appropriate candidates for domestic industrial use. The industrial potential of seaweed biomass was also explored by comparing the predicted amount of biomass necessary to replace current gasoline and plastics use with currently available farming space. The results of our study imply that once a steady and adequate supply of the proper kinds of seaweed can be secured through seaweed farming, there is a great potential for the development of new seaweed-based biofuels and bioplastics industries in Korea.

• Korean Journal of Environmental Biology
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• v.30 no.3
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• pp.193-199
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• 2012

We performed qualitative and quantitative surveys on the distribution of seaweed species and dominant species with their standing crop and temporal variations in Hauido tidal flats in order to understand the role of seaweeds in a coastal wetland ecological system that may be used for conservation and management of coastal wetland ecological system. A total of 9 species were found at 7 stations of the study area; 4 species of Chlorophyta (Ulva compressa, U. prolifera, U. pertusa and Ulothrix flacca), 3 species of Phaeophyta (Ectocarpus arctus, Scytosiphon lomentaria and Myelophycus simplex) and 2 species of Rhodophyta (Gracilaria verrucosa and Caulacanthus okamurae). Major dominant species were U. compressa, U. prolifera and U. pertusa (Chlorophyta), Scytosiphon lomentaria (Phaeophyta) and Gracilaria verrucosa (Rhodophyta). Standing crops of U. compressa and U. prolifera were $2.94{\sim}45.25g{\cdot}dw{\cdot}m^{-2}$ and $6.19{\sim}91.9g{\cdot}dw{\cdot}m^{-2}$, respectively, in spring. Seaweed habitat was characterized by textural differences that the percentage of coarse particles and organic material were a little higher in seaweed flourishing areas than in seaweed barren areas.

• Fisheries and Aquatic Sciences
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• v.11 no.3
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• pp.159-165
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• 2008

Intertidal benthic algal communities on the shores of Gujido and Daeyeonpyeongdo islets, Korea, were examined in October 2007. At both sites, 45 seaweeds including 7 green, 6 brown and 32 red algae were identified. The number of species at Gujido(38 species) was 1.5 times higher than at Daeyeonpyeongdo(25 species), but seaweed coverage was very similar with about 20%. Dominant seaweeds in terms of coverage and importance value were Hildenbrandtia sp., Caulacanthus okamurae, Ulva pertusa, and Gelidium amansii at Gujido and U. pertusa, Hildenbrandtia sp., Gelidium divaricatum at Daeyeonpyeongdo. The vertical distribution pattern of the seaweeds was G. divaricatum-U. pertusa, Hildenbrandtia sp.-U. pertusa, Hildenbrandtia sp., Ishige okamurae from upper to lower intertidal zone but seaweed zonations were not observed on the Gujido rocky shore. At both sites, coarsely-branched forms were the dominant functional group in species number and percent cover(among benthic algal species). The rocky shores of the two sites were dominated by crustose coralline and green algae, whose presence generally results in decreased seaweed biodiversity and community stability. Therefore, the shores of the Yeonpyeongdo islets are of considerable environmental concern and should be monitored for seaweed species composition and community structure.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.1
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• pp.300-307
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• 2015

Seasonal variation in marine macroalgal community structure was examined at the intertidal zones of Geumgap, Jindo, Korea, from October 2013 to August 2014. In total, 56 macroalgal species were identified, including 9 green, 12 brown, and 35 red algae. Annual seaweed biomass was 548.96 g wet wt. /$m^2$ with seasonal range between 371.08 g wet wt. /$m^2$ at summer and 32.91 g wet wt. /$m^2$ at winter. The dominant seaweed in terms of biomass was Sargassum thunbergii and subdominant species were Gelidium elegans, Sargassum fusiforme, and Ishige okamurae. The vertical distribution of seaweeds from the upper to lower intertidal zones was Gloiopeltis spp., Ulva spp.- S. thunbergii, S. fusiforme, Ishige okamurae - S. thunbergii, S. fusiforme, G. elegans. Annual seaweed coverage, richness index (R), evenness index (J'), and diversity index (H') values were 27.95%, 6.10, 0.38, and 1.38, respectively. Coarsely branched form was the most dominant functional group in terms of species number and biomass among benthic macroalgal species.

• Fisheries and Aquatic Sciences
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• v.12 no.1
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• pp.29-34
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• 2009

Fifty seven species of common seaweed from the coast of Korea were screened for antifungal activity against Malassezia species. Seaweeds as a source of bioactive compounds are able to produce a great variety of secondary metabolites with different activities. There are numerous reports on the biological activities of seaweeds against human pathogens, fungi, and yeasts, but only few contain data regarding inhibitory effects against Malassezia sp., a major cause of dandruff and seborrheic dermatitis. To help address this paucity of information, this work was carried out to examine the antifungal effects of seaweed extracts against M. furfur and M. restricta. Of the fifty seven species of marine algae screened for their potential antifungal activity, only 17 species (29.8%) exhibited inhibitory activity. In agar disc diffusion method, the ether extracts of Corallina pilulifera, Enteromorpha linza, Laminaria japonica, Symphyocladia latiuscula and Ulva sp. showed strong antifungal activity. To identify major constituents in seaweed extracts, four selected extracts were analyzed on' a GC-MS equipped with a flame ionization detector, and compared to spectral data from databases WILEY229.LIB and NIST107.LIB. Most constituents in seaweed extracts are fatty acid-related compounds. When we evaluated any acute toxicity, the ether extracts of the selected four species were not toxic in mice. According to these results, it can be suggested that these seaweed extracts are valuable for the development of therapeutic agents in treating dandruff and seborrheic dermatitis. Further investigations to determine its bioactive compound(s) are currently in progress.

• ALGAE
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• v.35 no.2
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• pp.107-121
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• 2020

Mariculture is regarded as the only option to supply the increasing demands for seaweeds as human food, feeds, fodder, and phycolloids in a sustainable manner. Technologies for culturing a range of seaweed species have been developed successively in Korea since the 1970s. In 2017, Korean marine farms produced 1,761,526 t of seaweed. The key focus of the industry is on the production of Pyropia (523,648 t), Undaria (622,613 t), and Saccharina (542,285 t). Pyropia is economically the most important species in Korea, accounting for up to 68% of total production value. As the top exporter of Pyropia in the world, Korea exported up to US $525 million of Pyropia products to 110 countries in 2018. Other economically important genera include Sargassum, Ulva, Capsosiphon, Codium, and Gracilariopsis, all of which are used for food, and Gelidium, Pachymeniopsis, and Ecklonia which are used as raw material for phycocolloid extraction. Significant work has gone into developing more productive strains of key seaweed species, and in 2012 the Korean government began to certify seaweed varieties. To date, 19 seaweed cultivars have been registered including 13 Pyropia, 5 Undaria, and 1 Saccharina. The industry is now seeking not only to increase productivity but also to add value through processing. Convenience foods and snacks have been developed that target health-conscious consumers and utilize the nutritional properties of seaweeds. The industry is also seeking to promote the sustainability of seaweed farming. One seaweed company in Korea obtained the world's first ASC-MSC (Aquaculture Stewardship Council-Marine Stewardship Council) certification in 2019 and more are expected to follow their lead. With continued research support, the Korean seaweed industry plans to continue to expand to meet new market demands at a sustainable pace.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.1
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• pp.53-60
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• 2016

Seasonal variations in seaweed communities were examined at Gwanmaedo and Yeongsando, Korea, from May 2014 to February 2015. Eighty-nine species were identified, including 11 green, 20 brown and 58 red algae. Seventy-three and 74 species were identified at Gwanmaedo and at Yeongsando, respectively. Sargassum thunbergii and Myelophycus simplex were the dominant species, comprising 60.89 and 39.50% of total biomass, respectively, and S. fusiforme was subdominant at the two sites. Of six functional seaweed forms, the coarsely-branched form was the most dominant, forming about 43% of the species number at Gwanmaedo and Yeongsando. Seasonal seaweed biomasses ranged between 53.10 and 172.85 g/m² (average 93.57 g dry wt./m²) and between 83.11 and 176.20 g (138.21 g/m²) at Gwanmaedo and Yeongsando, respectively. The vertical distribution from the high to low intertidal zone was S. thunbergii and Gloiopeltis furcata; M. simplex and S. thunbergii; and S. fusiforme at Gwanmaedo. Seaweed zonation was distinct at Yeongsando, with S. thunbergii and Gelidiophycus freshwateri; M. simplex and S. thunbergii; and S. thunbergii and S. fusiforme. Seaweed biomass, evenness index (J'), and diversity index (H') values were greater at Yeongsando (138.21 g/m², 0.51, 2.18 respectively) than at Gwanmaedo (93.57 g/m², 0.48, 2.04), indicating that the seaweed community at Yeongsando is more stable than that at Gwanmaedo.