• Korean Journal of Environmental Biology
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• v.17 no.4
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• pp.503-512
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• 1999

The morphological variations and habitat environment of the Zostera asiatica Miki (Zosteraceae) were examined in the waters off the eastern coast of Korea and Akkeshi Bay of Japan. In this study, we report new habitat of Z. asiatica along the eastern coast of south Korea； Gonghunjin, Donghori, Youngdong and Chilpo. Z. asiatica is found at the depth of 8∼15 m in these areas. However, Z. asiatica grows at the depth of 3 m in Akkeshi Bay of Japan. The sediment of habitats in the eastern coast of Korea were principally composed of sand. The stems were 64.0∼75.7 cm long in mature plants with flowering shoots and the leaves were 11.0∼15.0 mm wide for Korean populations. Plants from Akkeshi Bay of Japan had stems of 187.0∼234.0 cm in length. The difference in size are considered to be due to the depth of habitats. In spite of the significant morphological difference between Korea and Japan population of Z. asiatica, there was no difference in ITS sequences.

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

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.501-507
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• 2000

Distribution and habitat characteristics of Zostera (Zosteraceae) in the eastern coast of Korea were examined along with plant monohology, sediment composition and physicochemical factors of seawater from June 1998 to July 2000, The results showed that three species, Zostera marina, Z. asiatica and Z, caespitosa were found in specific habitats. The depth of habitat for Z. asiatica was deeper ($8.5{\~}15.0 m$) than that of Z. marina ($1.3{\~}5.6 m$) and Z. caespitosa ($3.2{\~}5.2 m$). Z. marina beds were observed at brackish-water, port and inner bay with the sediment type of sand or muddy sand. Habitats of Z. asiatica were restricted to the open bay with the sediment type of sand, Zostera have been described with regard to different growth forms of vegetation, flowering shoot and life history. Vegetation and flowering shoot length varied significantly with habitats; values ranged $66.8{\~}110.0 cm$ and $128.0{\~}217,8 cm$, respectively. Morphology of Z. marina varied with water depth and different substrates. Morphological characteristics of Z. asiatica showed a new phenotype at the deeper water depth. Vegetation and flowering shoots of Z. caespitosa were not significantly different between study sites (values ranged from 64.9 cm to 70.3 cm). Nutrient concentrations of seawater were higher at southern part than at middle part of the eastern coast of Korea. Distribution of Zostera in the eastern coast of Korea was dependent upon differences in water depth and habitat environments, by which affected the morphological differences were affected.

• KSBB Journal
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• v.27 no.4
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• pp.227-231
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• 2012

Whole plants of Zostera asiatica were extracted twice with acetone/methylene chloride (A+M) and methanol (MeOH) in turn. The combined crude extracts were evaporated in vacuo and then the residue was partitioned between water and methylene chloride. The aqueous layer was fractionated into $H_2O$ and n-butanol and then the organic layer was also fractionated into 85% aq. MeOH and n-hexane, successively. The crude extracts and their solvent fractions were evaluated for their inhibitory effect on growth of human cancer cells AGS, HT-29, MCF-7, and HT-1080 cells by MTT reduction assay. Among samples tested, 85% aq. MeOH and n-hexane fractions showed strong cytotoxic effect against AGS, HT-29, and MCF-7 cells. On the other hand, for HT-1080 cell, 85% aq. MeOH fraction exhibited the strongest cytotoxic effect.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.406-407
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• 2000

한반도에 서식하는 해초(Seagrass) 중 거머리말속(Zostera, Zosteraceae)은 거머말(Zostera marina), 애기거머리말(Z. japonica), 왕거머리말(Z. asiatica), 수거머리(Z. caulescens), 포기거머리말(Z. caespitosa) 5종이 기재되었다 (Miki, 1932). 이 해들은 연안의 사질 또는 사니질에 서식하며 생태계에 중요한 역할을 담당하고 있다. 그러나 연안의 매립과 개발로 인해 이들 해초지의 감소와 연안생태계의 붕괴가 진행되고 있으나 해초에 대한, 특히 Zostera속에 대한 연구는 미진하다.(중략)

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.4
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• pp.117-131
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• 2020

Although most species in genus Zostera inhabit shallow coastal areas and bays with weak wave energy, the Asian eelgrass, Zostera asiatica is distributed in deep water depth (8-15 m) unlike other seagrasses on the eastern coast of Korea. To examine factors limiting distribution Z. asiatica in relatively deep coastal areas, a transplantation experiment was conducted on October 2011, in which Z. asiatica shoots were transplanted from the reference site (donor meadow, ~9 m) to the shallow transplant site (~3 m). We compared shoot density, morphology, and productivity of Z. asiatica as well as environmental factors (underwater irradiance, water temperature, and nutrients) between the reference and transplant sites from October 2011 to September 2012. Shoot density and shoot height of transplants dramatically decreased within a few months after transplantation, but were similar with Z. asiatica in the reference site during spring. Shoot productivity were significantly higher in the transplant site than in reference site because of high light availability and nutrient concentrations. Transplants showed photoacclimatory responses such as higher rETR_max and E_k and lower photosynthetic efficiency in the transplant site than those in the reference site. Most of Z. asiatica transplant in the shallow transplant site disappeared in summer, which may be due to the high wave energy and physical damages induced by typhoons (TEMBIN and SANBA) in August and September 2012. According to the results of this study, Z. asiatica could not survive in shallow areas despite of more favorable light and nutrient conditions. Thus, Z. asiatica may restrictively occur in deep areas to avoid the intense physical stresses in the shallow area on the east coast of Korea.

• Journal of Plant Biology
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• v.26 no.4
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• pp.197-206
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• 1983

Flora and distribution of vascular hygro- and hydrophytes were investigated from April to June, 1983 on the seven sampling sites along the estuary of Nagdong River. As the result, total 60 kinds of vascular plants are investigated, among them 13 kinds are aquatics; Rotala indica var. uliginosa, Myriophyllum spicatum, Allisma canalicultum, Vallisneria asiatica, Hydrilla verticillata, Potamogeton berchtoldii, P. crispus, Ruppia maritima, Phyllospadix iwatensis, Zostera marina, Juncus effusus, Phragmites communis, and Scirpus triqueter. Present hydrophytes are largely confined to the main-stream zone. The transition zone is poorly habitated by hydrophytes and considered for the distributconfined to the estuary and coastal zone. However, long-term conditions of salinity gradient appear to be primarily responsible for the present flora and distribution.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.4
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• pp.957-970
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• 2016

This study diagnosed the status of marine environmental impact assessment(MEIA) for project near the habitat of marine protected seagrass species such as Zostera caespitosa, Zostera asiatica, Phyllospadix iwatensis. For the preparation of a marine environmental impact statement, different monitoring parameters are used without any specific guideline for the assessment of current status. And also, both tools and techniques for MEIA are needed to improve for implementing. The monitoring plans and parameters are not considered well with the accuracy of the environmental predictions and effectiveness of any applicable mitigation measures. This study suggested the reasonable standard of the MEIA for the conservation of the marine protected seagrass species which have the habitat located near affected area. The inshore seagrasses need to be monitored including shoot count based on the "No Net Loss of Seagrass" as part of the monitoring parameters to assess the status of marine environment of environmental impact statement. In a process of effect prediction, we suggested a concentration of 10 mg/L suspended solids which added by the new developmental project near seagrasses habitat, referring to study of overseas case. But a further study for an appropriate standard is necessary effectively. In a mitigating process, priority needs to be considered in order of avoidance, minimization, reduction, compensation. In a post-monitoring process, it is necessary to monitor the seagrass species abundance to identify the variation of b/a (before and after) project. And in a case of implementing transplantation, survival rate need to be included to determine a success of project.