• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.4
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• pp.220-225
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• 2007

The succession of marine benthic algae and the restoration of an artificial seaweed forest on a porous type (shaped half saw teeth) artificial reef at Jeju island, Korea was studied. Young thalli of Sargassum horneri and Ecklonia cava were attached to different artificial substrates. In general, the succession on the artificial reefs led from filamentous algae to perennial algae and involved more than 25 species that are useful fishery resources, including E. cava. Coralline algae were dominant on the artificial reefs at the Kangjung site. The maximum algal biomass on the artificial reef in October 2005 was $1,990g/m^2$ at Biyang. In conclusion, a climax community and seaweed forest can be attained one year after the substrate is constructed.

• Fisheries and Aquatic Sciences
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• v.23 no.3
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• pp.9.1-9.6
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• 2020

Background: Fucosterol is a compound commonly found in algae that has various biological activities. The purpose of this study was to develop a high-performance liquid chromatography (HPLC) validation method for fucosterol and to compare the fucosterol contents of 11 algal species from Ulleungdo, Korea. Method: In this study, we successfully isolated and identified fucosterol from a 70% EtOH extract of Sargassum miyabei, and subsequently conducted specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision analyses for development of an HPLC validation method. Fucosterol contents were compared using the established HPLC validation conditions. Results: We successfully isolated fucosterol from a 70% EtOH extract of S. miyabei and identified it based on spectroscopic analysis. On the basis of HPLC validation using the fucosterol isolated from S. miyabei, we confirmed specificity (8.5 min), linearity (R² = 0.9998), LOD (3.20 ㎍ mL^-1), LOQ (9.77 ㎍ mL^-1), accuracy (intra-day and inter-day variation, 90-110%), and precision (RSD, 1.07%). Fucosterol contents in the 11 assessed algal species ranged from 0.22 to 81.67 mg g^-1, with the highest content being recorded in a 70% EtOH extract of Desmarestia tabacoides (81.67 mg g^-1), followed by that of Agarum clathratum (78.70 mg g^-1). Conclusions: The results indicate that 70% EtOH extracts of D. tabacoides and A. clathratum containing fucosterol with various effects can be potential alternative sources of fucosterol.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.532-539
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• 2010

Seaweed biomass was estimated in the rocky subtidal zone of Daejin on the mid-east coast of Korea using a destructive sampling method from February to November 2007. Monthly sampling was conducted at depths of 5, 10 and 15 m using 50 $\times$ 50 cm quadrats. A total of 73 species, including 5 chlorophytes, 25 phaeophytes, 43 rhodophytes and one seagrass were identified. Average seaweed biomass was 2,852.3 g wet wt. $m^{-2}$ and biomass values varied monthly from 1,189.8 g to 7,523.7 g. The species dominant in biomass were Laminaria japonica (481.7 g), Sargassum confusum (470.85 g), Undaria pinnatifida (422.57 g), Costaria costata (282.16 g), Odonthalia corymbifera (174.46 g), S. sagamianum (163.22 g) and S. horneri (122.18 g). The vertical distribution of algae was characterized by S. confusum and U. pinnatifida at 5 m, L. japonica and U. pinnatifida at 10 m, and O. corymbifera and L. japonica at 15 m depth. The C/P, R/P and (R+C)/P values were 0.20, 1.72 and 1.92, respectively.

• ALGAE
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• v.23 no.4
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• pp.295-300
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• 2008

Seaweed biomass was estimated using a nondestructive method in the rocky subtidal zones in Munseom, Jeju Island, Korea from July 2006 to April 2008. Seasonal samplings were done at the depth of 1, 5, 10 m using 50 x 50 cm quadrat. Mean biomass was comprised of 2,784 g wet wt m$^{-2}$ and the biomass values varied seasonally from 1,176 g wet wt m$^{-2}$ to 4,217 g wet wt m$^{-2}$ with the highest point in April. Biomass reached maximum at 5 m depth in spring, but was shifted to 10 m depth in summer. Common seaweeds appeared year round in Munseom were Codium minus, Ecklonia cava, Sargassum spp., articulated corallines and Plocamium telfairiae. Among them, E. cava showed the highest biomass (average of 1,288 g wet wt m$^{-2}$), comprising 4% of total biomass. Only 12 species’' biomass covered 98% of total value, which indicated the contribution of few common species to algal community. Seaweed biomass in Munseom represented one of the highest values in coastal regions in Korea.

• 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.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.1
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• pp.35-42
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• 2011

Behaviour habitats of sailfin sandfish, Arctoscopus japonicus, one of the stock recovery species of Korea, were investigated when they were approaching toward the eastern coastal waters of Korea during spawning season. Underwater surveys were conducted in December, 2009 at Jug-island, Goseong, Gangwon-province to observe the behaviour of sailfin sandfish by underwater video camera and underwater camera, and the body characteristics of sailfin sandfish caught by gillnet were measured. It was observed that the species generally move in school but a few of individuals go out of the school to approach and dig into the sand bottom. Eggs of sailfin sandfish were shown in many cases to be attached to seaweed like Sargassum fulvellum and Zostera mairna. The females maintain its body in horizon and shake the body to breed eggs. It was also observed that the males spray sperm on the eggs attached on seaweed. Sailfin sandfish is assumed to make diurnal migration by moving to the shallow coast at night for spawning and fertilization, and moving out to the offshore at sunrise.

• Journal of Fisheries and Marine Sciences Education
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• v.3 no.2
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• pp.29-46
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• 1991

Benthic marine algal community of a sea bank at Joomoonjin, in the eastern coast of Korea, was investigated monthly in view of floristic composition and seasonal periodicity during from August, 1989 to July 1990. Total number of benthic alga identified were 70 taxa, which composed of 7 species of Chlorophyta, 21 species of Phaeophyta and 42 species of Rhodophyta. The dominant species were Sargassum horneri, Underia pinnatifida, Laminaria japonica and Pachymeniopsis sp.. Vegetation, from the point of phygiognomy, was a mosaic type by these dominant species. The flora was compared with similarity index using S${\phi}$rensen coefficient and grouped by a cluster analysis. As a result, the algal community of this area could be divided into two clusters at similarity level 45% : Flora of water temperature-ascending period(January-July) and flora of water temperature-descending period(August-December). And also, the former flora was subdivided into two clusters at point of the $14^{\circ}C$ sea water temperature : winter flora(January-April) and spring-summer flora(May-July). The flora of this area was characterized as a mixed flora of cold and temperature zone by Cheney's index.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.182-197
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• 1993

Algal community on the subtidal rocky zone of the South Sea of Korea was divided into two or three sequencing zones. The upper subtidal zone was characterized by the wave exposure-tolerant surf wrack(Pachymeniopsis, Gigartina), which formed dense swirling carpet. Its vertical range was from the surface to $3{\sim}5$ meters in depth, and more deeply extended in turbid waters including Sorido, Yokchido, Pijindo, Manjedo. The mid subtidal zone ranging from 5 to 25 meters in depth was characterized by a large brown algal forest (Ecklenia, Sargassum). But it was generally unrecognizable in that turbid waters, in which the vertical limit of vegetation was at most $10{\sim}15$ meters in depth. The low subtidal zone was characterized by a general lack of algal species and was not easily distinguished from the mid or sometimes from the upper zone. There was a distinct difference in abundance of vegetation between turbid waters and clear waters including Munsom, Kwantaldo, Yosodo, Hongdo, Ch'ujado. In turbid waters the vegetation was much poorer because the tubidity caused from the muddy sediment inhibited an algae to settle down and to grow up. On the basis of the phytogeographical methods using UPGMA, the 10 studied islands were classified into two groups, Munsom and the others. This floristic discontinuity between the two groups might be caused from the difference of water temperature.

• Journal of Life Science
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• v.27 no.10
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• pp.1121-1129
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• 2017

The authors evaluated the scavenging activities of ABTS+ radical, hydroxy radical (OH), nitric oxide (NO), and ferric ion reducing antioxidant power (FRAP) from ethanol extracts of four edible alga, Enteromorpha linza, Porphyra tenera, Sargassum fusiforme, and Undaria pinnatifida. ABTS+ scavenging activity was analyzed according to the method of Brand-Williams et al. ABTS+ scavenging activity of S. fusiforme was evaluated to 61.8% at 8.0 mg/ml. ABTS+ scavenging activity of P. tenera was evaluated to 35.7% at 8.0 mg/ml. P. tenera and U. pinnatifida showed similar inhibitions of ABTS+ scavenging activity. According to the results of the OH assay in seaweed, inhibitory activities were in the order of S. fusiforme > P. tenera > U. pinnatifida > E. linza. The results showed scavenging activity for NO in the following order of potency: S. fusiforme > P. tenera > U. pinnatifida > E. linza with concentration values of 8.0 mg/ml. The NO scavenging activities of dough, which was instant noodles mixed with S. fusiforme and 3.5% salt, were 27.2% at 8.0 mg/ml. After boiling for 5 minutes, FRAP scavenging activity of instant noodles mixed with extracts of U. pinnatifida was evaluated to 31.5% at 8.0 mg/ml. S. fusiforme showed the highest inhibition activity of ABTS+, OH, NO, and FRAP among the four algae. Thus, these findings provide evidence that P. tenera, U. Pinnatifida, S. fusiforme, and E. linza extracts could become sources of natural antioxidants.

• Journal of Nutrition and Health
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• v.51 no.6
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• pp.507-514
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• 2018

Purpose: Sargassum horneri (S. horneri) is a species of brown macroalgae that is common along the coast of Japan and Korea. The present study investigated the immuno-modulatory effects of different types of S. horneri extracts in RAW264.7 macrophages. Methods: S. horneri was extracted by three different methods, hot water extraction, 50% ethanol extraction, and supercritical fluid extraction. Cell viability was then measured by MTT assay, while the production levels of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6), and nitric oxide (NO) were measured by enzyme-linked immunosorbent assay and Griess assay, respectively. The expression and activation levels of inducible NO synthase (iNOS), mitogen-activated protein kinase (MAPK) and nuclear factor ${\kappa}B$ ($NF-{\kappa}B$) were examined by western blot analysis. Results: The three different S. horneri extracts were nontoxic against RAW 264.7 cells up to $50{\mu}g/mL$, among which treatment with hot water extract (HWE) of S. horneri significantly enhanced the production of TNF-${\alpha}$, IL-6, and NO in a dose-dependent manner. Hot water extract of S. horneri also increased the expression level of iNOS, suggesting that up-regulation of iNOS expression by HWE of S. horneri was responsible for the induction of NO production. In addition, treatment of RAW 264.7 macrophages with HWE of S. horneri increased the phosphorylation levels of ERK, p38 and JNK. Furthermore, the activation and subsequent nuclear translocation of $NF-{\kappa}B$ was enhanced upon treatment with HWE of S. horneri, indicating that HWE of S. horneri activates macrophages to secrete TNF-${\alpha}$, IL-6 and NO and induces iNOS expression via activation of the $NF-{\kappa}B$ and MAPKs signaling pathways. Conclusion: Taken together, these findings suggest that HWE of S. horneri possesses potential as a functional food with immunomodulatory activity.