• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.277-278
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• 2003

The Korean populations of Z. marina are typically distributed in patches. Although molecular and biochemical approaches are now increasingly being applied to address the taxonomic and phylogenetic relationships within the animals, plants, and other algal species in Korea (Huh 1998; Hwang et at. 1998; Huh 2001), no population genetic studies of this species have been conducted. (omitted)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.532-542
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• 1997

Seasonal variation of a shrimp community in the eelgrass (Zostera marina) bed in Kwangyang Bay, Korea was studied based on the monthly collected samples through a year of 1994. The shrimp community in the eelgrassbed was composed of 26 species of shrimps representing 6 families. The community was dominated by Heptacarpus pandaloides, Crangon affinis, Eualus leptognathus, Latreutes acicularis, Heptacarpus rectirostris, Heptacarpus geniculatus, and Latreutes laminirostris. Most of species were the small-sized species with carapace length smaller than 25 mm. The peak abundance occurred in the late winter and spring and low abundances in autumn. More than 10 species were collected every month except lull (8 species). Species diversity indices showed that the shrimp species were more diverse during the late summer, and lesser during the late autumn. Predominance of Crangon affinis in the late autumn caused such a low diversity. The shrimps in the study area could be grouped into three groups on the basis of their occurrence patterns: resident species, seasonal species, and temporary species. More abundant and more diverse shrimps were collected during nighttime than daytime.

• The Journal of the Acoustical Society of Korea
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• v.23 no.8
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• pp.562-569
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• 2004

An experiment for observation of the distribution of the seagrass (zostera marina) beds and characteristics of high-frequency backscattering by the photosynthesis was conducted off the coast. Acoustic data were taken as a function of the grazing angles and the relative azimuth angles on the seagrass beds of which bottom type was sandy-mud. The transmitted source signal was a 120 kHz CW waveform. Mapping of the seagrass beds distribution was drawn up using the seagrass backscattering strength with azimuth and grazing angles. The result of the comparison backscattering strength distribution of the seagrass beds was shown to be the similar to the photograph of real seagrass beds. The seagrass backscattering strength was also compared between day and night to verify the effects of the acoustical scattering by the bubbles of Photosynthetic oxygen formed on the seagrass. In these results. it is clear that observation of the seagrass beds between day and night showed the different characteristics because the bubbles of Photosynthetic oxygen affect the acoustical scattering.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.744-752
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• 1997

A total of 60 species of benthic macrofauna was collected by a grab sampler in the eelgrass bed in Kwangyang Bay, Korea. The dominant group was Polychaeta which was composed of 32 species. The dominant species were Platynereis bicanaliculata, Cirriformia tentaculata, Lumbrineris longifolia, and Cirratulus cirratus which accounted for approximately $63.7\%$ of the total numbers of benthic macrofauna. Seasonal variations in both species composition and abundance of the benthic macrofauna were major characteristics in the study area. Seasonal peak of number of species and abundance occurred in summer. And the lowest abundance occurred in winter. Seasonal dominant species were Platynereis bicanaliculata, Cirriformia tentaculata, Lumbrineris longifolia in spring and summer, and Cirratulus cirratus, Capitella capitata, Opisthobranchia in fall.

• Journal of Life Science
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• v.17 no.4 s.84
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• pp.455-461
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• 2007

Assessments of population genetic structure and diversity can be of value in formulating management plans for threatened eelgrass(Zostera maim). Using randomly amplified polymorphic DNA markers, we found evidence of significant genetic structure among the populations of eelgrass sampled at three areas(Geojedo, Gaedo, and Jedo). A highly isolated(>100 km apart) population from the Geojedo had a long genetic distance(0.16), whereas the populations from the Gaedo and Jedo(<10 km apart) exhibited far less distance(0.08). The analysis of similarity within population showed that Geojedo was over 70%, which was of lower value than of Gaedo and Jedo. Based on these results, we realized that heterogeneous population was in accordance with geographic separation. This is caused by limited seed dispersal and interrupted gene flow, although the sample size is small.

• 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 Environment and Ecology
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• v.23 no.5
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• pp.431-438
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• 2009

The main purpose of this research is to prepare and provide basic materials for the propagational strategy of eelgrass by investigating on the morphological adaptation of Korean Zostera marina to ocean currents. An eelgrass plant mainly consists of rhizome, leaf sheath, leaves and roots. The rhizome is the horizontal stem of the plant that serves as the backbone from which the leaves and roots emerge. The leaf sheath is the bundle at the base of the leaves that holds the leaves together, protecting the meristem, the primary growth point of the shoot. Leaves originate from a meristem which is protected by a sheath at the actively growing end of the rhizome. As the shoot grows, the rhizome elongates, moving across or within the sediment, forming roots as it progresses. The aggregated leaves from the leaf sheath are found to have two cell layers on one side and multiple layers of airy tissues called aerenchyma on the other. The aerenchyma tissues are developed in multi-layered cell structures surrounding the veins which are formed in the leaf sheath. Generative shoots are made of rhizomes, which are circular or ovoidal, stem, and spathe and spadix. The transverse section of rhizome and the stem and central floral axis is found to be circular, ovoid and in the shape of convex respectively, and the vascular bundle, which is a part of transport system, has one large tube in the center and two small tubes on both sides. The layers of collenchyma cells numbered from 12 to 15 in the stem, and from 7 to 12 in the rhizome. The seed coat is composed of sclereids, small bundles of sclerenchyma tissues, which prevent the influx of sea water from the outside and help endure the environmental stress. In conclusion, alternative multi-layer structure in circular, convex type aggregated leaf base are interpreted to morphological adaption as doing tolerable elastic structure through movement of seawater. The generative shoots develop long slim stem and branches in circular or ovoidal shapes to minimize the adverse impacts of sea current, which can be interpreted as the plant's morphological adaptation to its environment.

• 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.

• Animal cells and systems
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• v.13 no.3
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• pp.315-321
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• 2009

The growth and estimated production of Acanthogobius flavimanus (1.9${\sim}$24.7 cm TL) were investigated in an eelgrass bed and unvegetated tidal flat of Dongdae Bay, Korea from March 2006 to February 2007. Growth in fish total length was expressed by the von Bertalanffy's growth equation as: $L_t=43.238(1-e^{-03138(t+02507)})$. Estimated densities, biomass, daily and annual production, and P/B ratio were higher at eelgrass bed than those of at unvegetated tidal flat. Monthly variation in daily production was large; the peak numbers occurred in November 2006 ($0.0014g/m^2$/day) at eelgrass bed, whereas was $0.002g/m^2$/day in July 2006 at unvegetated tidal flat. The eelgrass bed has been supported to maintain capacity of higher production of A. flavimanus than those of in unvegetated tidal flat.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.187-190
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• 2004

본 논문에서는 연안에 서식하는 잘피(Zostera Marina)의 시공간적 분포와 생산성을 파악하기 위해 음향실험을 통한 분석을 시도하였다. 해저면이 니질로 구성된 잘피 서식지에 수평입사각 및 방위각에 따라 120 kHz 및 50 kHz 음원을 이용하여 송${\cdot}$수신 하였다. 수평입사각 및 방위각에 대한 수신 신호의 산란강도를 표현하였으며 그 분포양상이 실제분포와 유사한 경향을 보인다. 각 음원의 주${\cdot}$야간별 신호에서는 산란강도의 차이가 관측되었다. 이를 통해 잘피의 광합성에 의한 공기방울의 음파산란 영향에 대한 가능성을 확인하였다.