• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.5
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• pp.533-542
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• 2011

Numerous seagrass habitat restoration projects have been attempted recently due to the remarkable decline in seagrass coverage. Seagrass transplants tend to adapt to a new environment after experiencing transplanting stress during the early stages of transplantation. Once acclimated, the transplants grow into healthy seagrass beds via vegetative propagation. The establishment and growth dynamics of transplanted seagrasses in bays and coasts are widely reported, but few studies have been conducted on estuaries in Korea. We transplanted Zostera marina in November 2007 and November 2008 in the Nakdong estuary using the staple method, and monitored the survival, adaptation, and growth dynamics of the transplants as well as environmental factors every month for 1 year. Both transplants adapted well to the new environment without initial losses and showed rapid productivity during early summer. However, density of transplants increased 320% in 1 year from the previous year's transplants but that decreased to 59% during the following year. This significant reduction in density in the second year may have been caused by exposure to low salinity (10 psu) for 3 weeks during the unusually long monsoon season. While the survival and growth dynamics of seagrass transplants planted in bays and coasts are mainly controlled by underwater photon flux density and water temperature, salinity was the critical factor for those planted in Nakdong estuary.

• ALGAE
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• v.23 no.3
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• pp.241-250
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• 2008

Since seagrasses in the coastal and estuarine ecosystems achieve high levels of production, they require high inorganic carbon and nutrient incorporation. Thus, seagrasses may play a significant role in carbon and nutrient cycling in the coastal and estuarine ecosystems. To examine growth dynamics of Zostera marina L. environmental factors such as underwater irradiance, water temperature, and salinity, and biological parameters such as shoot density, biomass, shoot morphology, and leaf productivity were measured in two bay systems (Jindong Bay and Gamak Bay) on the southern coast of Korea. While underwater irradiance did not show distinct seasonal trend, water temperature at both sites exhibited clear seasonal trend throughout the experimental period. Shoot density increased dramatically during winter due to the increased seedlings through germination of seeds in Jindong Bay and due to the increased lateral shoots in Gamak Bay. Eelgrass biomass increased during winter and decreased during summer. Maximum biomass in Jindong Bay and Gamak Bay was 250.2 and 232.3 g dry weight m–a2, respectively. Carbon incorporation into the eelgrass leaf tissues was estimated from productivity and leaf tissues carbon content. The calculated annual carbon incorporations at the Jindong Bay and Gamak Bay sites were 163 and 295 g C m–`2 y–`1, respectively. This high carbon incorporation into seagrass tissues suggests that seagrass habitats play an important role as a carbon absorber in the coastal and estuarine ecosystems.

• KSBB Journal
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• v.30 no.4
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• pp.182-190
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• 2015

The Zostera marina ethanolic extract (ZMEE) was tested in this study to investigate the anti-inflammatory activity in LPS-induced RAW 264.7 cells and mouse model. Nitric oxide production and inducible nitiric oxide synthase expression in cells treated with ZMEE was reduced significantly in a dose-dependent manner. Similarly, the secretion of pro-inflammatory cytokines such as interleukin (IL)-6, IL-$1{\beta}$, and TNF-${\alpha}$ was inhibited markedly. In addition, the expression of nuclear factor kappa B (NF-${\kappa}B$) and the phosphorylation of JNK, ERK, and p38 MAPKs was suppressed by ZMEE as well. In vivo test, ZMEE attenuated the croton oil-induced mouse ear edema and there were no mortalities in mice administered 5,000 mg/kg body weight of ZMEE during the observation periods. The results in photomicrograph of mice ear tissue showed the reduction of dermal thickness and the number of infiltrated mast cells. These results indicate that ZMEE inhibits the production of LPS-induced pro-inflammatory mediators, suggesting that ZMEE may be a potential material for anti-inflammatory therapies.

• Archives of Pharmacal Research
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• v.27 no.2
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• pp.177-183
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• 2004

In order to develop new anti-photoaging agents, we examined the antioxidative activity and the inhibition effect of matrix metalloproteinase-1 (MMP-1) on the extracts of a marine product, Zostera marina L., which is known for its potent activity. Three compounds (compounds 1, 2, and 3) were isolated from an ethyl acetate (EtOAc) soluble fraction of the product; they were identified as apigenin-7 -O-$\beta$-D-glucoside (1), chrysoeriol (2), and luteolin (3). These compounds were found to scavenge radicals and reactive oxygen species (ROS) and were measured to have $SC_{50}$/ values of 0.18 mM, 0.68 mM, and 0.01 mM against the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and 0.04 mM, 0.03 mM, and 0.01 mM against the superoxide radical in the xanthine/xanthine oxidase system, respectively. Compound 3 suppressed the expression of MMP-1 by up to 44％ at 4.0 $\mu$M and inhibited the production of interleukin 6 (IL-6), which is known as a cytokine that induces MMP-1 expression. From these results, compound 3 and the other compounds were determined to have antioxidative activity and to inhibit MMP-1 expression. Thus, the three compounds are expected to be useful for preventing the photoaging of skin.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.535-544
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• 1998

Seasonal variation of the crab community in the eelgrass (Zostera marina) bed in Kwangyang Bay was studied based on the monthly collections through a year of 1994. The crab community in the eelgrass bed was composed of 21 species representing 12 families. The community was dominated by Charybdis Japonica, Telmessus acutidens, Hemigrapsus penicillatus, and Pugettia quadridens. Crabs collected in the study area were primarily small-sized species or early juveniles of large crab species. Most individuals had carapace width smaller than 25 mm except C. japonica and T. acutidens which had maximum carapace width over 85 mm. More than 5 species were collected every month except January and February (4 and 3 species, respectively). The peak abundance occurred in August and low abundances in autumn and winter. Species diversity indices showed that more diverse crabs were collected In spring and summer, and lesser ones in autumn and winter. The crabs in the study area can be grouped into three groups on the basis of their occurrence patterns: resident species, seasonal species, and temporary species. More abundant and more diverse crabs were collected during nighttime than daytime.

• Korean Journal of Environmental Biology
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• v.30 no.1
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• pp.47-53
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• 2012

To evaluate adaptation success of $Zostera$ $caespitosa$ transplants, we transplanted the seagrass shoots at the bare area in close proximity to the donor bed using staple method in October 2005. Shoot density, morphological characteristics and leaf productivity of transplants and reference plants in the vicinity of the planting site were monitored monthly for 2 years. While shoot density of reference plants exhibited significant seasonal variations; increasing during spring and summer and decreasing during fall and winter, that of transplants increased consistently without initial loss during the whole study period. Although sheath length, leaf width and shoot height and weight of sheath, leaf and shoot of transplants were smaller than those of reference plants at the start of transplantation, increased rapidly reaching even higher values than those of reference plants 5 months after transplantation. Leaf productivity of transplants and reference plants showed seasonal variations; increasing during spring and summer and decreasing during fall and winter. But, leaf productivity of transplants increased at the beginning of transplantation during fall which is low production period. All of the $Z.$ $caespitosa$ transplants survived during the whole study period. Rapid changes in shoot morphology and growth of transplants indicated that $Z.$ $caespitosa$ transplants had great morphological plasticity and adapted successfully within 5 months.

• Korean Journal of Environmental Biology
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• v.19 no.4
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• pp.313-320
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• 2001

An ecological study was conducted to determine the geographic distribution, community structure, and habitat characteristics of eelgrass, Zostera marina L. beds along the southern coast of Korea. Plants and sediment samples were collected during June 2000 and December 2000 on twenty-eight locations, including two Cheju Island stations, which were used to compare morphological characteristics with habitat types. Z. marina populations existed from the intertidal to subtidal zone, mainly in the bays along the coast and the island, the barrier reef, and the estuary where the water depth was 0.5${\sim}$8.0m. Salinity range in Z. marina beds ranged 18.2 to 34.5%$_o$. Sediments of Z. marina beds contained 49.7${\sim}$99.1% of sand and were classified into sand, muddy sand, and sandy mud. Mean grain size varied from 1.5 to 4.4 phi. Height of vegetation shoots varied from 54.7 to 171.4 cm, depending on water depth, location, substrata and habitat types. quantitative morphological features that enabled recognition of the two phonetic groups were short-narrow leaf type and long-broad leaf type. Statistical analysis indicated that biomass of individual plants and their quantitative morphological characteristics were significantly correlated.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.2
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• pp.164-168
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• 2014

To determine the optimal storage method and longest possible storage period of Zostera marina seeds, we examined post-storage germination rates using different storage methods and periods for Z. marina seeds harvested in southern coast of Korea. Storage methods included in seawater at room temperature with air supply, seawater at $4^{\circ}C$, seawater at $30^{\circ}C$, an aquarium with continuous seawater circulation, seawater at room temperature in an airtight tank, a refrigerator at $-20^{\circ}C$, and a desiccator at room temperature. Germination rates of Z. marina seeds stored in seawater at $4^{\circ}C$ showed highest germination (52.0%), whereas those of seeds stored in seawater at room temperature and an aquarium were 27.4% and 17.7%, respectively. But the seeds stored in seawater at $30^{\circ}C$, a refrigerator, and a desiccator did not germinate. Storage periods were 10, 20, 30, 60, 180 and 240 days of storage. Z. marina seeds maintained germination rates of 46.4~52.4% until 10~60 days of storage, but showed rapidly decreasing germination rates after then and no germination after 240 days.

• Ocean and Polar Research
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• v.27 no.1
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• pp.67-74
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• 2005

The phonology and reproductive effort of Zostera marina L. (Dongdae Bay and Aenggang Bay) on the southern coast of Korea were investigated from September 2002 to August 2003. The Dongdae Bay(DB) exhibited a finer sediment grain size with richer organic content than the Aenggang Bay(AB). Water temperature at DB site ranged from $7.5^{\circ}C$ in February to $25.5^{\circ}C$ in August, while water temperature at AB site ranged rrom $6.7^{\circ}C$ in February to $25.2^{\circ}C$ in september. Both populations exhibited a perennial lifB span, but the sexual reproductive effort was significantly higher at DB than AB. The reproductive shoots of DB site were developed from February to June 2003, while those of AB site from March to June 2003. At DB site, the frequency of reproductive shoot ranged from 11 to 33%, whereas reproductive shoot of AB did below 5%. Reproductive structures were larger and more abundant at DB, with the exception of number of fruits and seeds per spadix. Water temperature seems most important to regulate the timing of reproductive phase of Z. marina populations for two study sites.

• Korean Journal of Environmental Biology
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• v.20 no.4
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• pp.339-346
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• 2002

From March 1998 to August 2000, the phonology and morphometrics change of Zostera caespitosa Miki were examined at the Duksan Port in the eastern coast of Korea. Morphometric characteristics (shoot height, leaf length, sheath length, leaf width, and number of leaf per shoot), size and number of reproductive structures (spathe, spadix, and seeds), shoot density, biomass and physiochemical parameters (water temperature and nutrient concentrations) were measured. Significant differences between months (p < 0.05) existed for morphometric characteristics except for sheath length. The sequence of shoot heights clearly showed cyclical annual variation with water temperature. Vegetative shoots of Z. caespitosa were present throughout the year, but reproductive shoots were rarely occurred from mid January to early April in water temperature of $9-12^\circ{C}$. Flowering in the spathe began in mid February, and seed maturing was occurred in early April. Water column nitrate and phosphate concentration showed seasonal variation, but ammonia concentration was variable with season. Relationships between shoot morphometrics and physiochemical parameters were not significantly correlated but water temperature seemed to regulate the re-productive phase and annual life cycle. The mean shoot density and above biomass of the populations were $511.6\pm{25.6}\;shoots\;m^{-2}$ and $413.4\pm{19.8}\;g\;dry\;wt\;m^{-2}$, respectively.