• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.2
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• pp.122-128
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• 2004

On the basis of monthly samples, we investigated the seasonal variation and feeding habits of amphipods inhabiting Zostera marina beds in Gwangyang Bay. Dominant species $(>1\%$ of the total number of amphipods) consist of 5 gammarids (Gammaropsis japonicus, Jassa slatteryi, Pontogenia rostrata, Atylus collingi and Ceinina japonica) and 1 caprellid (Caprella tsugarensis). Mean densities of amphipods varied from the highest of $63,148\;ind.\;m^{-2}$ in-May to the lowest of $1,247\;ind.\;m^{-2}$ in September. G. japonicus and J. slatteryi dominated in summer whereas C. japonica in autumn and winter. C. japonica was found to be a carnivorous feeder consuming mainly harpacticoid copepods and unidentified crustaceans, whereas G. japonicus, J. slatteryi, and C. tsugarensis consumed both phytoplankton and detritus. Seasonal densities of amphipods were significantly related with the shoot standing crop of the eelgrass and its epiphyte. Also densities of amphipods displayed significant difference in related with the shoot density of the eelgrass among sampling stations. These results suggest that the biological interactions between the eelgrass and amphipods as well as between the carnivorous and the herbivorous amphipods may be important in the seasonal variation of amphipods inhabiting Z. marine beds.

• 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.

• 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.

• 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.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.5
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• pp.681-691
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• 2022

Zostera marina (ZM), a type of seagrass registered as a marine protected species in South Korea, provides valuable ecosystem services to humans, such as improving marine water quality, providing food, spawning grounds and habitats for marine life, and absorbing carbon dioxide. Therefore, the government is seeking to preserve ZM by designating ZM-protected areas. This study examined the public willingness to pay (WTP) for the preservation of ZM using contingent valuation. The one-and-one-half-bounded model was adopted for WTP elicitation, and the single-bounded model was also applied for comparison. The spike model was employed to deal with many zero WTP responses. The household average WTP was estimated as KRW 4,087 per year, securing statistical significance. The national value was KRW 84.1 billion per year. The preservation value of ZM estimated in this study can be used as important data for economic analysis of various projects or policy implementation for its preservation.

• 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.

• 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.

• 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.

• Journal of the korean society of oceanography
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• v.39 no.3
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• pp.186-196
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• 2004

Since seagrasses are highly productive and provide a source of organic carbon for a wide variety of marine organisms in coastal and estuarine ecosystem, accurate assessment of seagrass production is critical to understand the functions and values of seagrasses in these ecosystems. Zieman's leaf marking technique has been mostly used to estimate seagrass leaf production rates. However, inherent problems on the traditional leaf marking technique have been discussed by the several researchers, and these problems can cause underestimation of seagrass production. To develop an accurate and reliable assessing method for seagrass production, production rates of eelgrass, Zostera marina in three bay systems on the south coast of the Korean peninsula were estimated using the conventional leaf marking technique and the plastochrone method. The plastochrone method has been recently suggested as an effective method for reliable assessments of seagrass production. In the present study, leaf production rates estimated by the plastochrone method were significantly higher than the rates derived from the traditional leaf marking technique. Annual eelgrass leaf production assessed using the leaf marking technique was about 65 to 89% of the estimated production using the plastochrone method. The differences in annual productions between assessment techniques imply that the conventional leaf marking technique significantly underestimated eelgrass leaf production. Total eelgrass productions estimated using the plastochrone method in the present study sites were about 600 to 806 g DW $m^{-2} y^{-l}$, and below-ground production accounted for about 20 to 23% of the total production. The plastochrone method was suggested to be an effective and accurate assessing method for eelgrass production.