• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.spc1
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• pp.236-241
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• 2006

We measured the secondary production of the amphipod Monocorophium acherusicum Costa in a seagrass bed (Zostera marina L.) in Gwangyang Bay, southern Korea. M. acherusicum biomass was positively correlated (P<0.05) with seagrass standing crop, suggesting that there were biological interactions between the two species. M. acherusicum displays two main breeding periods per year: spring (March to April) and fall (October to November). M. acherusicum biomass in the spring breeding periods was higher than in the fall. Annual secondary production of M. acherusicum was 3.54 g DW/$m^2$/yr with an annual P/B ratio of 3.48. Secondary production and the P/B ratio of M. acherusicum were lower than those observed for other amphipods inhabiting seagrass beds. These results suggest that biological interactions between M. acherusicum and seagrass, as well as dietary competition with other amphipods can potentially cause declines in secondary production and the P/B ratio.

• Fisheries and Aquatic Sciences
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• v.24 no.3
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• pp.121-128
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• 2021

The variations of morphological features, density and biomass of vegetative shoots and characteristics of reproductive shoots of Zostera caespitosa were examined in Tongyeong, Korea. Morphological features such as leaf length, width and sheath length of Z. caespitosa showed significant seasonal variation (p < 0.001). The highest aboveground value was recorded in late spring to summer and the lowest value in winter. Density and biomass also showed seasonal variations. Annual average shoot density and biomass of Z. caespitosa were recorded as 1,223.4 leaf m^-2 and 5,956.9 g w.w.m^-2, respectively, and had the highest value in June and lowest values in November and January. Reproductive shoots were observed from April (13℃) to June (21℃). Pistils erected outside sheath, anther dehiscing and small embryos were found in April. Mature fruit and released seeds were found in May and June. These results suggest that this species had a high growth rate in late spring and early summer (15℃-20℃). Reproductive shoots of Z. caespitosa may initially appear at about 10℃ in spring and seed have been released at about 20℃ in fall.

• Journal of Life Science
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• v.27 no.3
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• pp.346-350
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• 2017

Seaweeds have a number of secondary metabolites, such as polyphenols, polysaccharides, and carotenoids, and have received much attention as a source of natural antioxidants. Thus, this study was carried out to examine the antioxidant activities from ethanol (EE) and water (WE) extracts of Zostera marina. Their antioxidant effects were investigated using total polyphenol contents (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, reducing power, and chelating effect. TPC of EE and WE was 2.12 mg/g and 3.88 mg/g, respectively. DPPH radical scavenging activities of EE and WE were increased in a dose-dependent manner. In particular, EE had DPPH radical scavenging activity of 93% at a concentration of 0.5 mg/ml, and was higher than that of WE (71%). EE and WE increased reducing power in a concentration-dependent manner, but their effects were lower than that of the control (ascorbic acid). In case of chelating effect, WE was 66% at a concentration of 1 mg/ml, and was stronger than EE (6%). These results suggest that extracts of Zostera marina can be potentially used as proper natural antioxidants in the food industry.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.107-116
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• 2018

In this study, the distribution of sedimentary environment and benthic macro-fauna in habitats and non-habitats of Zostera marina were investigated. The purpose of this study was to obtain basic data about the sedimentary environment and benthic macro-fauna in the habitats and non-habitats of Z. marina. Sand was dominant within habitat environments, whereas the non-habitats were predominantly composed of silt. As a result, the habitats of Z. marina have a different grain size and organic matter content compared to the non-habitats. These differences in the sedimentary environment were expected to influence the species composition of benthic animals. Benthic communities in the habitats of Z. marina showed a higher density and a greater number of species than in the non-habitats. As a result of an ecological index evaluation, the species diversity index (H') was $3.44{\pm}0.10$ for the habitat; the non-habitat was analyzed as $2.34{\pm}0.35$. It was also found that the stability of community in the habitats was higher than that in the non-habitats. The cluster analysis also clearly showed that habitats and non-habitats of Z. marina have distinct characteristics.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.235-240
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• 2004

In order to develop new anti-photoaging agents from marine natural products, Zostera marina L. was selected for its antioxidative activity and inhibition of matrix metalloproteinase-1 (MMP-1) expression. Three compounds (compounds 1, 2, and 3) were isolated from the extract, and they were identified as apigenin-7-O-${\beta}$-D-glucoside (1), chrysoeriol (2), and luteolin (3). These compounds have SC$\_$50/ values of 0.18 mM, 0.68 mM, and 0.01 mM against l,l-dipheny1-2-picrylhydrazyl radical and 0.04mM, 0.03mM, and 0.01mM against the superoxide radical in the xanthine/xanthine oxidase system, respectively. Compound 3 suppressed the expression of MMP-1 by up to 44% at 35.0${\mu}$M and inhibited the production of interleukin 6, which is known as a cytokine that induces MMP-1 expression. In addition, the wrinkle improvement effect of the formulation with Z. marina extract was measured. As a result, remarkable reduction was found in the fine wrinkle and skin roughness after application of the cream with 3.0% this extract for 8 weeks. In conclusion, the isolated compounds from Z. marina extract were good antioxidant and suppressor of MMP-1 expression and the formulation with the extract diminished the skin wrinkle. Therefore, the extract can be used as a new anti-aging agent for application in cosmetic.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.2
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• pp.70-77
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• 2003

From March 1998 to August 2000, the phenological and morphometric changes of Zostera marina L. were examined at the Duksan Port in the eastern coast of Korea. Morphometric characteristics, phenological stage, shoot density, biomass of Z. marina population and environmental parameters were also measured. Nutrient levels in water column varied over the season. Morphometric characteristics of vegetative shoot changed with season; shoot heights ranged from 54.2 cm (March) to 100.0 cm (October). Reproductive shoots appeared from mid-March to early September of which the height was ranged from 97.8 cm (March) to 213.0 cm (July). The flowering phase started at 12$^{\circ}C$ and the fruit development was resulted up to 21$^{\circ}C$. The seed maturing was developed at 22$^{\circ}C$-$25^{\circ}C$. Shoot density and biomass in permanent quadrate (0.25 m$^2$) were significantly different among seasons ranging from 38 to 136 shoots (mean 80.3$\pm$6.5) for shoot density, and 190 g dry wt m$^{-2}$ in October 1998 to 922 g dry wt m$^{-2}$ in June 1998 for biomass respectively. Relationships between shoot morphometrics and physico-chemical parameters were not significantly correlated. Seasonal changes in water temperature seemed responsible for the replacement of reproductive phases and the annual changes of shoot morphometrics in Z. marina populations.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.4
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• pp.106-116
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• 2020

To examine distribution of the Zostera species growing naturally in Ulleungdo, scuba diving surveys using ships were conducted along the coast and inside the harbors of the island at the end of September 2019. In areas of seagrass occurrence, environmental factors such as nutrient concentrations in water column and sediment pore water, salinity, and sediment organic content were also analyzed. Zostera caulescens meadows appeared in the relatively deep waters (14-24 m MSL) of Cheonbu-ri, Jeodong-ri, Sadong-ri, and Namyang-ri in Ulleungdo, and the total seagrass coverage was approximately 4.9 ha. Approximately 0.9 ha of Zostera marina meadow was found at the depths of 3-5 m MSL within Hyeonpo-hang in Hyeonpo-ri. The average shoot density and biomass of Z. caulescens were 121.9±9.7 shoot m^-2 and 99.0±13.2 gDW m^-2, respectively, with no significant differences by location. The average shoot density and biomass of Z. marina were 193.8±18.8 shoot m^-2 and 102.6±6.8 gDW m^-2, respectively. The nutrient concentrations in the sediment pore water and sediment organic content in the seagrass meadows in Ulleungdo were lower than those in eelgrass meadows on the southern and eastern coasts of Korea. These results will provide useful basic information for the marine protected species, Z. caulescens and Z. marina, and for the conservation of the waters of Ulleungdo, which has been designated as a marine protected area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.4
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• pp.184-191
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• 2010

Epiphytic diatoms are very important organisms in the seagrass ecosystem because their colonization on leaves increases microtopography and provides attachment sites that make the leaves more hospitable for other epiphytes. Epiphytic diatoms were attached to the leaves in the following 3 manners: (1) parallel to the cells of the seagrass leaf or by molding the shape of the diatom along the cell shape of the leaf; (2) with increasing diatom density toward the leaf tip; (3) Cocconeis species as attaching species than the Naviculoid species as the second attaching species on the leaf tip. In addition, the epiphytic diatom communities on Zostera marina leaves differed from those on the Zostera japonica leaves, but were very similar to the epiphytic communities on Zostera caespitosa leaves. Our results suggest that the epiphytic community on seagrass leaves varied according to the leaf shape such as leaf length and width, but the leaf cell shape or size did not influence the dynamics of the diatom communities.

• 한국생태학회:학술대회논문집
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• 1999.05a
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• pp.129.1-129.1
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• 1999

• 한국생태학회:학술대회논문집
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• 1999.05a
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• pp.111.2-111.2
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• 1999