• Korean Journal of Food Science and Technology
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• v.6 no.1
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• pp.36-41
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• 1974

Gracilaria verrucosa and Gelidium amansii collected from Wando, Yeosoo and Namhae districts Gracilaria sp. imported from Manila, and Ecklonia cava from Cheju island were investigated to raise the extraction yield of agar or alginic acid. The results are summarized as follows. In agar extraction from domestic seaweeds, Gelidium sp. showed 8-10% yield increase by gamma-irradiation whereas Gracilaria sp. exhibited no effect. In Manila seaweed, gamma-irradiation (1.5 Mrad) caused 25-30% increase in agar extraction and the properties of agar sample by these methods were acceptable. In alginic acid extraction from Ecklonia sp., gamma-irradiation (0.3 Mrad) showed 6% yield increase.

• Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.130-137
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• 2009

Temporal variations of seaweed biomass and coverage were seasonally examined at Ongdo in the Yellow Sea, Korea from August 2006 to April 2008. Average seaweed biomass was 245.79 g/$m^2$ in wet weight and coverage was 16.49% with seasonal variations from 13.97% in spring to 18.55% in autumn. Seaweeds were distributed across the shore gradient from the high intertidal to 10m depth in the subtidal zone. Biomass was always higher in the subtidal zone (310.24 g/$m^2$) than in the intertidal zone (181.35 g/$m^2$). Of total seaweed biomass, 76.52% (first year) and 80.32% (second year) occurred from the low intertidal zone, down to depth of 1 to 5m. Gelidium amansii had the highest importance value and biomass, and sub dominant species were Chondrus ocellatus and Chondria crassicaulis. Coarsely-branched seaweeds comprised the highest proportion of biomass (214.84 g/$m^2$, or 87.41% of the total biomss). Seasonal variations in algal biomass were largely explained by fluctuations in the biomass of coarsely-branched and thick-leathery forms. In conclusion, seaweed biomass of Ongdo shore was very low because of perennial G. amansii showing low biomass as compared to kelp or Sargassum spp. However, these results indicate Ongdo is good place to grow seaweeds because coarsely-branched form seaweeds including G. amansii are dominant at unpolluted and clean environment.

• ALGAE
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• v.19 no.1
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• pp.69-78
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• 2004

This study was to clarify the variations in a marine ecosystem through examining the species composition of benthic algae in the coast of Dokdo Island during summer (June & August, 2003). The total number of species found in benthic algae was 45 composed of 11% green algae, 29% red algae and 60% brown algae. The dominant species were Enteromorpha linza, Cladophora spp. and Codium frgile for green algae, Ecklonia cave, Eisenia bicyclis, Sargassum confusum, S. patens, S. horneri, Myagropsis myagroides for brown algae and Amphiroa cphedrace. A pusilla, Lithophyllum okamurae, Corallina spp. Laurencia pinnata, L. hamata, Chondria crassicaulit, C. dasyphylla, Gelidium amansii, Neosiphonia yendoi and Polysiphonia yendoi for red algae. The number of benthic algal species decreased more in this study than in previous researches. The whitening of the rocky shore might provoke the decrease of benthic algal biomass and species.

• Journal of Environmental Science International
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• v.8 no.4
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• pp.503-507
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• 1999

To study the residue of organophosphorus pesticides in the ocean environment on the Cheju island, EPN[O-ethyl-O-4-nitrophenyl phenylphosphonothioate] and monocrotophos [Dimethyl-1-methyl-2-methyl carba-moylvinylphosphate] of organophosphorus pesticides are surveyed on coastal environment of Cheju city and Wimi in May and October 1996. The qualified limit detection of EPN and monocrotophos are 0.005ng/mL and 0.006ng/mL in the water by GC-FPD, respectively. The qualified limit detection of EPN and monocrotophos are 0.010ng/g and 0.012ng/g in the solid such as sediment and sea organism by GC-FPD, respectively. EPN and monocrotophos are not detected in seawater and sedimnet. Moreover EPN and monocrotophos are neither detected in seaweed cava (Ecklonia cava), Agar (Gelidium amansii), turban sell(Batillus cornutus) and sea urchin(Anthocidaris Crassispina). EPN, monocrotophos used in the farm on the Cheju island are not residued in the coastal environment in the Cheju island.

• ALGAE
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• v.20 no.1
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• pp.61-67
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• 2005

Agar was extracted from Gelidium amansii, which was harvested at the shores of Jeju Island in South Korea. As a unique solvent, the ability of dimethyl sulfoxide (DMSO) was used to separate agarose from agar by removing agaropectine and quality of the resultant agarose was characterized for chromatography purposes. Agar sample was agitated by motor-driven stirrer with DMSO in a water bath (at 70$^{\circ}C$ for 2 h) and centrifuged (3,000 rpm for 20 min). Resultant upper agarose layer was gelled, washed, dried and milled. The quality of agarose was evaluated by the analysis of proximate chemical composition, sulfate content, gelling strength and DNA migration. In this study, the separated agarose showed low sulfate amount (0.28%) and showed high gel strength (1190 g ${\cdot}\;cm^{-2}$). The resolution power and the ligase activities gave clear picture about the suitability of the present agarose for practical purposes.

• Fisheries and Aquatic Sciences
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• v.11 no.2
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• pp.76-81
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• 2008

We isolated 1,916 strains of bacteria from gut and feces of abalone. The most active agarolytic bacterium, DAG-130, was identified from the gut of the abalone Haliotis gigantea. Of the bacteria harbored by both H. discus hannai and H. gigantea, 59% were agarolytic. There was no significant difference in the number of agarolytic bacteria isolated from abalone fed on the seaweeds Gelidium amansii, Laminaria japonica, or Undaria pinnatifida. Of the agarolytic bacteria, 72% were isolated from the guts of all sources tested while 43% came from the feces. The strain DAG-130 showed 100% identity with the bacterium Vibrio cyclotrophicus based on phylogenetic analysis of l6S rDNA. The bacterium produced monomers and oligomers from the agar substrate.

• Korean Journal of Environmental Biology
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• v.29 no.1
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• pp.31-45
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• 2011

To understand the marine algal flora on Goheung coast, Korea, marine algae at 8 points were collected from November 2008 to February 2009 and from April to June 2009. Thirty-seven species (2 species of angiosperms, 5 chlorophytes, 12 phaeophytes, and 18 rhodophytes) occurred from fall to winter and 52 species (2 species of angiosperms, 9 chlorophytes, 18 phaeophytes, and 23 rhodophytes) occurred from spring to summer. Commonly occurring species were Ulva pertusa, Sargassum thunbergii, Hizikia fuziformis, and Gelidium amansii, and dominant species at most points were Ulva pertusa, Sargassum thunbergii, and Gelidium amansii. The average of the ratio of total rhodophytes and chlorophytes to phaeophytes ((R+C)/P) was 1.61 in fall to winter and 1.69 in spring to summer, and the average Laminariales/Fucales/Dictyotales (LFD) ratio was 1.14 in fall to winter and 1.18 in spring to summer. These results show that the marine algal flora of Goheung could be considered as temperate. The LFD ratio was fit for showing a feature of algal flora of Goheung. Species diversity index was high at Points 4~6 while low at Points 1 and 8. Detrended correspondence analysis (DCA) showed that the similarity of occurring species at Points 3 and 4 was higher than the other points from fall to winter, whereas the occurred species at Points 1~4 were similar from spring to summer. The average values of ecological evaluation index (EEI) of the investigation points were 6.8 from fall to winter and 6.3 from spring to summer, which means that the ecological environment of the investigation points were middle class and the EEI values of outer sea points were higher than the inner bay points.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.4 no.3_4
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• pp.105-112
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• 1971

The annual variation of algal vegetation at two reefs, A and 3, of Odong-do, Yeosu, was observed two times each month during the period from June 1970 to May 1971, and the results obtained are as follows : 1. The total number of the algal species occurred were 69 species, of which 12 species belong to Chlorophyceae, 17 species to Phaeophyceae and 40 species to Rhodophyceae. No significant difference was noticed in the occurrence number of algal species at the reefs observed. 2. Most species of the algal communities in each algal belt did not show seasonal variations, but the following species showed fluctuations iii cover degree : Ulva pertusa, Enteromorpha sp., Sphacelaria sp., Scytosiphon iomentaria, Colpomenia sinuosa, Sargassum thunber gii, Pterocladia tenuis, Amphiroa ephedrea, Carpopeltis affinis, Gigartina tenera, Polysiphonia yendoi, Chondria crassicaulis, Symphyocladia atiuscula. 3. The species occurred in each algal belt at all two reefs did not show much variations and the main species in each belt are as follows: $200\~150cm$ belt - Gloiopeltis complanata, G. furcata, Enteromorpha sp., etc. : $150\~100cm$ belt - Ulva pertusa, Chondria crassicaulis, Sargassum thunbergii, etc. ; $100\~50cm$ belt - Gigartina tenera, Pterocladia tenuis, Scytosiphcn lomentaria, Polysiphonia yendoi, etc ; Below 50cm- Sargassum sagamianum, Cystophyllum sisymbrioides, Gelidium amansii, Acresorium yendoi, Microcladia elegance, etc. 4. The species occurred below 100cm level were almost the same at A and B reefs, but those above 100cm level at the A leef were different from the B reef; th: species of the algal belt of reef A were composed of Gloiopeltis complanata, Corallina pilulifera, Chondria crassicaulis, Sargassum thunbergii, Polysiphonia yendoi, Ulva Pertusa, etc., and those of reef B were composed of Gloiopeltis complanata, G. furcata, Enteromurpha sp. and Ulva pertusa, thus the main composition of reef B was very simple. 5. According to Taniguti's classification of marin: algal com nunity, the reefs observed belong to the Gigartina intermedia-Sargassum sagaminnum association (Sargasseto-Gigartinetum Taniguti) of Myelophycus caespitosus alliance (Myelophycion Taniguti).

• Korean Journal of Food Science and Technology
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• v.17 no.5
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• pp.319-325
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• 1985

Agar was prepared from domestic agarophyte (Gelidium amansii) by a process of acid extraction. Optimal conditions in the acid treatment of the seaweed and the gelling properties of the agar thus prepared were investigated. The yield and gel strength of the control (the agar extracted with distilled water) showed 13,3% and 306g/$cm^2$, respectively. The yield of 38.7% was obtained when agar was extracted with 0.007N Hydorchloric acid while the gel strength of agar,511g/$cm^2$ was observed with the agar extracted with 0.005N Hydorchloric acid solution. The agar extracted with hydrochloric acid solution showed excellent properties of agar at the acid concentration range 0.005N-0.01N The cooking time of 60 min. was found to be effective to the yield and also to the gelling property of the agar and the cooking longer than 60 min. was proved to be destructive to agar. In general, yield and gelling properties of the agar obtained showed a close relation to the acid concentration and cooking time, but no consistent influence on the contents of ash and sulfur trioxide.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.389-397
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• 2011

The benthic algal community structures of the seaweed biomass, vertical distribution of dominant seaweeds, and species composition were examined on the rocky shores of Ongdo, Jusamdo, and Woejodo Islands, Korea, in August 2006. A total of 68 seaweeds were identified, comprising 5 green, 11 brown, and 52 red algae from the three study sites. The number of species at Ongdo (32 species) was less than that at Jusamdo (45 species) and Woejodo (44 species). Jusamdo exhibited the maximum seaweed biomass (73.99 g dry $wt/m^2$), while the minimum value was found at Woejodo (36.90 g dry $wt/m^2$). On the three islands, coarsely branched forms were the most dominant functional group in terms of species number and biomass among benthic algal species. The dominant species were Gelidium amansii, Chondrus ocellatus, and Chrysymenia wrightii at Ongdo, Sargasum thunbergii, Ulva pertusa, and Sargassum fusiformis at Jusamdo, and U. pertusa, Undaria pinnatifida, and Corallina pilulifera at Woejodo. Perennial seaweeds were abundant at Ongdo (G. amansii and C. ocellatus) and Jusamdo (S. thunbergii and S. fusiformis), whereas the sheet form of U. pertusa was relatively abundant at Woejodo Island.