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

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

• Proceedings of the Korea Society of Environmental Biology Conference
• /
• 2004.05a
• /
• pp.21-21
• /
• 2004

• Korean Architects
• /
• s.538
• /
• pp.74-78
• /
• 2014

• ALGAE
• /
• v.23 no.1
• /
• pp.75-81
• /
• 2008

The epiphytic diatom flora living on leaf tissues of Zostera marina, Z. japonica and Z. caespitosa at three study sites (Dadae, Gabae, and Jangmok) located in Geoje Island has been examined from July 2001 to March 2002 bimonthly. Total 81 species in 26 genera of diatoms have been observed on leaf tissues of the 3 Zostera species throughout the present study. Cocconeis spp. were predominant on Z. japonica, whereas Navicula spp. and Nitzschia spp. were predominant on Z. marina and Z. caespitosa. The community structure of the diatom assemblages varied according to the seagrass species. Species compositions of epiphytic diatoms appear to be closely related to morphology and lifespan of seagrasses.

• KSBB Journal
• /
• v.29 no.4
• /
• pp.271-277
• /
• 2014

In this study, crude extract of the seagrass Zostera japonica, and its solvent-partitioned fractions were evaluated for their antioxidant activity. The crude extract was successively fractionated into n-hexane, 85% aqueous methanol (85% aq.MeOH), n-butanol (n-BuOH), and water fractions by liquid-liquid partition. These include DPPH radical scavenging, hydroxyl radical scavenging in HT-1080 cells, peroxynitrite scavenging, and protective effect on DNA damage caused by hydroxyl radicals generated. In all assays, except for DPPH radical, 85% aq.MeOH and n-BuOH fraction showed the strong antioxidant activity. These results suggest that Z. japonica may be used as a potential source of natural antioxidants for the development of cosmetic product or functional food in the future.

• Animal Systematics, Evolution and Diversity
• /
• v.39 no.1
• /
• pp.16-21
• /
• 2023

In 2022, during a survey of intertidal fauna around Jindo located in the Dadohaehaesang National Park in the South Sea, epizoic hydroids attaching onto seagrass (Zostera sp.) growing on soft sediments were collected. Through taxonomic examination, an unrecorded species, Ectopleura radiata, is newly added to the hydrozoan fauna of Korea. In addition, DNA barcoding for species from Ectopleura and Tubularia clarified the distinction among morphologically indistinguishable species without gonophores. Up to now, only one species, E. crocea, has been reported in Korea. Through this study, a total of two species belonging to genus Ectopleura have been reported in Korean waters so far.

• Proceedings of the Zoological Society Korea Conference
• /
• 1998.10b
• /
• pp.82-82
• /
• 1998

No Abstract, See Full Text

• Korean Journal of Environmental Biology
• /
• v.30 no.3
• /
• pp.280-285
• /
• 2012

We investigated germination rate of Zostera marina and Phyllospadix japonicus, which are the most two abundant seagrass species of Korea, in related to light, salinity and temperature. Light had no significant effect on Z. marina germination, but it promoted P. japonicus germination. The highest germination of Z. marina appeared in 0 psu, and that of P. japonicus appeared in 15 psu. The optimum water temperatures for germination of Z. marina and P. japonicus were $5^{\circ}C$ and $15^{\circ}C$, respectively. These differences of optimum germination requirements of Z. marina and P. japonicus were probably caused by the difference of the habitat environment of the two seagrass species. Since few data exist concerning germination of Korean seagrasses, this study provides valuable information for the conservation of seagrass habitats in Korea.

• ALGAE
• /
• v.27 no.3
• /
• pp.215-224
• /
• 2012

Growth dynamics of the seagrass, Zostera marina were examined at the two stations (Myungju and Dagu) in Jindong Bay on the southern coast of Korea. Eelgrass leaf productivities, underwater irradiance, water temperature, dissolved inorganic nitrogen (DIN) in water column and sediments, and tissue carbon (C) and nitrogen (N) content were monitored monthly from March 2002 to January 2004. Underwater irradiance fluctuated highly without a clear seasonal trend, whereas water temperature showed a distinct seasonal trend at both study stations. Water column DIN concentrations were usually less than $5{\mu}M$ at both study sites. Sediment pore water $NH_4{^+}$ and $NO_3{^-}+NO_2{^-}$ concentrations were higher at the Myungju site than at the Dagu site. Eelgrass leaf productivity at both study sites exhibited a distinct seasonality, increasing during spring and decreasing during summer. Seasonal variation of eelgrass productivity was not consistent with seasonal patterns of underwater irradiance, or water temperature. Eelgrass tissue C and N content at both study sites also showed significant seasonal variations. Relationships between tissue C and N content and leaf productivities exhibited usually negative correlations at both study sites. These negative correlations implied that the growth of Z. marina at the study sites was probably limited by C and N supplies during the high growth periods.