• 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.26 no.4
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• pp.343-355
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• 2021

Eelgrass, Zostera marina L., was widely distributed around Sinyangseopji Beach in Bangdu Bay, on the eastern coast of Jeju Island, until breakwater construction in the late 1990s resulted in its complete loss. Six experimental sites were identified for restoration of the Z. marina bed in Bangdu Bay. Using the staple method, 500 Z. marina shoots were transplanted at each site in January 2019 and 2020. The transplants, along with environmental parameters, were monitored for 10 months following transplantation. There were significant differences in underwater irradiance, water temperature, and salinity among the sites, but all were suitable for Z. marina growth. The Ulva species, an opportunistic alga, appeared in spring and accumulated during summer at all sites; however, there was no significant effect of Ulva species on the survival and growth of the eelgrass transplants. Most of the transplanted Z. marina survived, and after 3 months, the density increased by 112.5-300% due to vegetative propagation, with a rapid rate of increase observed during spring and early summer at all sites. For 1-2 months after transplanting, the Z. marina shoots showed signs of transplant shock, after which the shoot density increased at all sites, confirming that all transplants adapted well to the new environment. However, in both 2019 and 2020, during late summer to early fall, the sites experienced heavy damage from typoons (twice in 2019 and three times in 2020) that hit Bangdu Bay. The transplants at two sites located in the center of Bangdu Bay were completely destroyed, but those at three sites located to the west of the bay showed a 192-312% increase in density. Thus, we confirmed that the Bangdu Bay Z. marina bed can be restored, with the highest probability of success for Z. marina restoration on the western side of Bangdu Bay, which is protected from typhoons.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.121-127
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• 1968

This research has been dealt with the nutritional component analysis of two kinds of non-edible marine algae, Sargassum herneri (Turner) C. Ag. and Zostera marina Linne which grow abundantly around the southern coast of Korea, These marine algae were mixed in several kinds of samples rates with the combined feed for poultry sold in the market. These were given to 35 chicken in seven test divisions respectively. We have experimented with 35 chicken grown up for two weeks after hatchout. The combined food for poultry obtained from the market was set up as control divisions. The experiments were as follows: 1) The average weight increase in each test division during feeding (Table 5, Fig.2). 2) Food conversion rate and food efficiency in each test division (Table 7). 3) The comparison of digestive rate of crude protein during feeding (Table 8), The results were as follows: 1) The weight increasing rate of the test animal stock fed the food containing $5\~10\%$ of Sargassum horneri (Turner) C. Ag. powder was higher than the rate of those fed only market food for poultry. 2) The stock given food containing $10\%$ Zostera marine powder showed lower growth than the control divison. 3) No apparent trouble owing to salt component involved in the marine algae was found. 4) The stock given food containing sodium glutaminate and Sargassum horneri (Turner) C. Ag. had better result than that without sodium glutaminate.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.1
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• pp.1-13
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• 2003

To investigate the community structure and meiofaunal density in seagrass/bare non-seagrass beds, a survey was conducted at three seagrass bed locations in Doomoojin of Baegryongdo, inner harbor of Eocheongdo in May 1999, and Yulim of Dolsando for every month from February to July 1999. Meiobenthic samples were collected from sediments within seagrass beds (SB) and non-seagrass bed (or adjacent to barren sand area, NSB). Nematodes were the most dominant group among representative 13 meiofaunal groups. The sub-dominant groups were benthic for-aminiferans, benthic harpacticoids, and annelids. The highest density of meiofauna was recorded at a seagrass bed of Yulim (7,244 ind/10 $\textrm{cm}^2$ in June), and lowest density was recorded at a non-seauass bed of Baegryoungdo (438 ind/ 10 $\textrm{cm}^2$ in May). For vertical distribution, the highest density of meiofauna was recorded at 0-2 cm depth, and the density abruptly decreased with depth in all stations. The density of meiofauna in size between 0.125 m and 0.25 mm was maximum. Sediment types for the study areas ranged from sandy to sandy mud by the Folk's classification. The density of total meiofauna, the number of taxa, and the density of the dominant groups (nematodes, benthic for-aminiferans, benthic harpacticoids, annelids) between SB and NSB were significantly different. The results clearly showed the importance of seagrass bed as suitable habitat for meiofauna.

• ALGAE
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• v.19 no.1
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• pp.49-57
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• 2004

This study was performed to obtain basic information on the ecology of Zostcra marina and to promote efficient conservation of this species which has been decline in Gamak Bay, Yeosu, Korea. Whater column characteristics and eelgrass morphology at Anpori, Jangsuri and Wonpori were investigated every month from December 1999 to November 2000. The water temperature, salinity and pH at the three sites were 10.0-27.0${\circ}C$,29.4-34.7% and 8.1-8.5, respectively. The water temperature at Anpori tended to be slightly lower than that at the other locations; the salinity at Wonpori from July to November was a little lower than that of the other locations. The concentrations of $NO_2$-N, $NO_3$_N, $NH_4$-N, $PO_4$-P and $Si(OH)_4$-Si at the three sites were 0.9-1.3, 2.0-6.2, 7.8-9.0, 3.0-3.6 and 22.2-30.2 uM, respectively. The concentration of $NO_3$-N at Wonpori from June to November was somewhat lower than that at the other locations; that of NH4-N at Jansuri was somewhat lower than the others. The mean shoot height and leaf width of the Anpori, Jangsuri and Wonpori populations were 80.6 cm and 0.9 mm, 90.0 cm and 1.0 mm, and 95.3 cm and 1.0 mm, respectively. The mean total shoot weight of the Anpori, Jangsuri and Wonpori ones was 24.5,31.0 and 29.7 & respectively. The mean leaf and branch numbers of the Anpori, Jangsuri and Wonpori populations were 16.5 and 2.6, 16.1 and 2.4 and 15.4 and 2.6 individuals, respectively. The correlation coefficients between shoot height and water temperature, leaf width and total shoot weight, leaf number and branch number, and $Si(OH)_4$-Si and $NO_3$-N were 0.726, 0.692, 0.862, and 0.693, respectively. The coefficients between shoot height and $NO_3$-N, total shoot weight and NO_3$-N, water temperature and $Si(OH)_4$-Si, water temperature and salinity, and water temperature and $NO_3$-N were -0.716, -0.536, -0.775, -0.685 and -0.685, respectively. The first four principal components explain 71.1% of the total sample variance. For axis 1, shoot height and water temperature tended to correlate with the population of Jansuri, followed by the Wonpori population, and $Si(OH)_4$-Si and $NO_3$-N tended to correlated strongly with the Anpori population. For axis 2, total weight, leaf width, leaf number and branch number showed a tendency to correlate with the Anpori and Jangsuri populations. For axis 3, the Anpori population tended to be influenced by $NO_2$-N and $PO_4$-P. For axis 4, the Wonpori and Jangsuri populations tended to be affected by salinity. The tendency, however, differed according to season.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.615-626
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• 2022

This study investigated the habitat characteristics and spawning ecology of Hippocampus haema (Syngnathidae) in Soando Island, Korea, from May 2015 to December 2016. The survey site where seahorses inhabit was mainly formed by seagrass of Zostera marina populations. Total density and biomass (Mean±SE) of Z. marina were the highest at 136±14.4 shoots/m² and 489.8g DW/m², respectively, in spring (May), while the total density was lowest at 93±7.0shoots/m²in autumn (October), and biomass was the lowest and at 122.3g DW/m² in winter (February). During the study period, 293 individuals were identified through a diving and kick net survey, and the total length of H. haema ranged from 10.1 to 87.0mm. Male individuals nurturing fertilized eggs or larvae appeared beginning in May and were collected until October in both 2015 and 2016. Juvenile individuals were captured beginning in July 2015 and June 2016. As a result of a comprehensive analysis of the spawning season characteristics, it was estimated that the spawning season of H. haema was from April to October. The number of fertilized egg or larvae inside the male brood pouch were 38.3±14.8 (20-76), and the number of fecundity identified from female were 47.2±8.6 (31-59). The male-to-female ratio of H. haema was 1:1.7, indicating the dominance of males.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.509-517
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• 2009

Seagrass meadows are important biogenic habitats for a wide variety of marine animals and plants, a source of organic carbon for commercially important animals, and act as a nutrient filter in estuarine and coastal ecosystems. As such, mapping the distribution of seagrass beds provides us with an important component of management and conservation strategies. To survey seagrass distribution within Deukryang Bay, we directly observed seagrass beds using SCUBA in Boseong-gun, Goheung-gun, and Jangheung-gun. Seagrass distribution in Geogeum and Gumdang islands were not observed. Specifically, we monitored the distribution area, species composition, morphology, density, and biomass of seagrass meadows. Seagarss beds were mapped for Daikum-ri coast, Deukryang island, Yongjeong-ri coast, Samsan-ri coast and Ongam-ri coast. Total seagrass coverage in Deukryang Bay was $5.1\;km^2$, $4.8\;km^2$ of which was Zostera marina, $0.3\;km^2$ Z. caulescence and $0.01\;km^2$ Z. japonica. Z. japonica was found in intertidal zones, Z. marina was found from the intertidal to subtidal zones of 2 m MSL (mean sea level) depth, and Z. caulescence was found in subtidal zones of 2.5-5 m MSL.

• Advances in Traditional Medicine
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• v.4 no.4
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• pp.253-260
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• 2004

Zosterin is a pectin from a seagrasses of the family Zosteraceae. Zosterin was given to rats intragastrically once 1h before the emotional stress or injection of indomethacin, or administration of 2, 4-D solution daily for seven days at dose of 100 mg/kg. The data obtained demonstrate that zosterin enhances resistance of the stomach tissue to various ulcerogenic factors (emotional stress, indomethacin, pesticide 2, 4-D). It was shown to possess a gastroprotective effect, which is accompanied by diminution of the number and sizes of destructive regions in the gastric mucosa during the ulcer affection, as well as reduction of ATP and glycogen deficit, decrease of lactate excess, and normalization of the energy balance in the gastric mucosa. According to its antiulcer effect, zosterin may be recommended for application in prevention and treatment of stomach diseases together with the basic therapy.

• 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.