• Korean Journal of Medicinal Crop Science
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• v.15 no.5
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• pp.357-361
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• 2007

This study was conducted to evaluate the vegetation structure of the Peucedanum japonicum community by the phytosociological method of floristic composition table and cluster analysis on the southern coast of Korea. The vegetation of the Peucedanum japonicum community was classified mainly into 2 communities such as the Miscanthus sinensis community and the Lysimachia mauritiana-Rosa wichuraiana community. The Carex boottiana and Sedum oryzifolium community were classified as the lower rank of Miscanthus sinensis community. On level 1 of the cluster analysis of plant species, they were classified into Lysimachia mauritiana and Rosa wichuraiana group, also Miscanthus sinensis, Carex boottiana and Sedum oryzifolium in Peucedanum japonicum community, which is similar to the community classification shown in the synoptic table. On level 1 of the cluster analysis of relev, inland coast with Jejudo was Lysimachia mauritiana and Rosa wichuraiana of group such as level 1 of the cluster analysis of plant species, and island coast with Geomundo was Miscanthus sinensis Carex boottiana and Sedum oryzifolium of group such as cluster analysis of plant species.

• Journal of Species Research
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• v.9 no.1
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• pp.56-67
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• 2020

Eight new species of two genera Dysidea and Euryspongia (Demospongiae: Dictyoceratida: Dysideidae) are described from Gageodo, Ulleungdo, Geomundo, and Jejudo Islands, Korea. Four new species of the genus Dysidea are differentiated by the fibre structure, cored detritus, and fibre arrangement. Dysidea mureungensis n. sp. is characterized by the honeycomb shape of surface and no distinction between primary and secondary fibres. Dysidea glavea n. sp. differs by large sands cored in fibres and that the membrane easily separates from fibres. Dysidea geomunensis n. sp. has fibres that are thinner than those of D. glavea n. sp.. Dysidea corallina n. sp. is characterized by folded fan shape and the arrangement of secondary fibres. Four new species of the genus Euryspongia are differentiated by the fibre structure, cored detritus, shape of sponge, and fibre arrangement. Euryspongia radicula n. sp. is very different from other species by having regularly arranged fibres. Euryspongia spina n. sp. has a fence-like skeletal structure. Bridged type secondary fibres are arranged near the surface and web types are at the base of fibres. Euryspongia flabellum n. sp. has a very unique wide, thin leaf-like shape. String-like primary fibres of E. linea n. sp. are very unique and cored with large sized sands.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.3
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• pp.278-291
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• 2024

This study performed three research methods (destructive, non-destructive, and panoramic image analysis) to determine the most useful for identifying seaweed habitat characteristics. Panoramic images are suitable for understanding the overall seaweed distribution. The composition of the main dominant seaweed species showed a significant difference between the destructive and non-destructive methods using Quadrat. The destructive method showed Rhodophyta dominance, whereas the non-destructive was showed Phaeophyta as dominant. Destructive methods are disadvantageous because they destroy natural communities in sea areas where bleaching is severe. Non-destructive methods are disadvantageous because of the difficulty in analyzing small species. Performing 10 surveys using a non-destructive method was found to explain up to 80% of the species identified by the destructive method. However, considering the difficulty of field investigation, repeating the investigation with non-destructive methods at least 6-7 times is necessary to ensure that more than 60% of the destructive methods can be interpreted. To understand the distribution of oceanic marine algae, performing both destructive and non-destructive surveys are necessary, as each has its own merits and demerits.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.3
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• pp.40-48
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• 2007

We analyze relation between phytoplankton and marine environment based on data such as water temperature, phytoplankton, zooplankton, nutrient collected from the southern coast of Korea in the summer, 2004. The water temperature range of the study area was $20.5{\sim}31.5^{\circ}C$ and there was formed a water temperature frontal zone from $20.5^{\circ}C$ to $25.0^{\circ}C$ in Geojedo southern coast and Geomundo island. Especially, high density of nutrients were shown in the southern coast of Geojedo in which water temperature frontal zone was formed strongly, the concentration of chlorophyll-a which is appeared at the highest rate among the phytoplankton pigments was shown more than $0.4{\mu}g/L$ in the inside of frontal zone and zooplankton biomass was than $500mg/m^2$ in that area.

• Korean Journal of Plant Taxonomy
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• v.36 no.1
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• pp.53-59
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• 2006

Here we report a previously unrecorded species of Korean Allium (Alliaceae) from Geomundo, Yeosu-si, Jeollanam-do. This taxon, A. pseudojaponicum Makino which has been known to distribute only in the southern part of Japan up to date, is easily distinguished from A. thunbergii G. don by lustrous evergreen leaves and lateral scapes as well as chromosome number (2n=32). The common name, 'Gaet-bu-chu', was newly given considering the property of habitat, which is the dry and rocky grasslands facing to the sea in Korea and Japan. In this study, we redescribe morphological characters, and provide illustrations of habit as well as photographs of habitat.

• Korean Journal of Ichthyology
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• v.31 no.3
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• pp.178-182
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• 2019

This is the first report of Brachirus annularis (Pleuronectiformes: Soleidae) from Korea. A specimen of B. annularis (229.0 mm standard length) was firstly collected by drift gill net at a fishing ground locating between Jejudo and Geomundo Islands, the southern coast of Korea on 31 March, 2019. This species was characterized by having five large, deep colored patches on the ocular side of body, each patch outlined by dark brown ring, united dorsal and anal fins jointed with caudal fin, and short pectoral fin. We add this species to the Korean fish fauna and propose its new Korean names, "Eol-luk-seo-dae-sok" and "Eol-luk-seo-dae" for the genus and species, respectively.

• Journal of Life Science
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• v.20 no.3
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• pp.336-344
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• 2010

To assess population structure and genetic diversity among the Pacific cod (Gadus macrocephalus), we investigated mtDNA COI gene sequences of 7 populations. Samples were obtained from Sokcho, Wolsung, Geojedo, Yeosu, Geomundo and Westsouth in 2008 and 2009 (n=28). The sequence analysis of 28 individual samples showed 8 haplotypes, ranging in sequence divergence by pairwise comparisons from 0.2 to 2.2% (1 bp-11 bp). The Gal haplotype was found in Wolsung, Geojedo, Yeosu, Geomundo and Westsouth, and was regarded as the main haplotype of Korean Pacific cod. Ga2, Ga3, Ga6 and Ga7 haplotypes were found only in Sokcho. In the PHYLIP analysis, 8 haplotypes formed two independent groups: cladeA consisted of Ga2, Ga3, Ga6 and Ga7 haplotypes, whereas cladeB contained Gal, Ga4, Ga5 and Ga8 haplotypes. The genetic relationship between the two groups was weakly supported by bootstrap analysis(<50%). In pairwise comparisons between 6 populations other than that from Sokcho, a very high per generation migration ratio ($N_m$=infinite) and a very low level of geographic distance ($F_{sr}=-0.0123-(-0.0423)$) were observed. The estimates of genetic distance between Sokcho and the other localities were all statistically significant (p<0.05, p<0.01, p<0.001), indicating a limited mtDNA-based gene flow between Sokcho and other regions. The finding of the lowest genetic diversity in the Sokcho population (nucleotide diversity=0.00589) may be a result of relatively small population size and interrupted gene flow to other localities. Consequently, the overall considerable migration of Pacific cod population in Korea caused a genetically homogeneous structure to form, although a distinct population was found in this study.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.3
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• pp.137-152
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• 2004

The climatological characteristics of coastal zone over the southwestern coast of Korea peninsula were investigated using the data observed by AWS (automatic weather system) and 4 buoy points. Coastal zone is climatologically defined as the region bounded by the distinct contrast of temperature gradient and wind speed across coastline. In the southwest of peninsula four cross-lines consisted of AWS aligned with each buoy were selected as Geojedo buoy line, Geomundo buoy line, Chilbaldo buoy line and Dukjukdo buoy line. Analysis on the diurnal cycle and intra-month variation, monthly mean and maximum value, the temperature gradient with distance between buoy and each station and the accumulative frequency of wind speed were applied to find out the characteristics and the range of coast zone. The maximum ranges of coastal zone vary from offshore to Sanglim (about 34 km distance from coastline) for Geojedo buoy line, to Sunchun (about 52 km) for Geo-mundo buoy line, to Jaeundo (about 27 km) for chilbaldo buoy line and to Yongin (about 65 km) for Dukjukdo buoy line. The modification of coastal zone according to synoptic flow was investigated for the onshore, off-shore and calm cases. The ranges of coastal zone are significantly changed with the distance between 65∼90 km for the case of onshore. In addition, we tried to find out the variation of the wind and temperature and the wind ratio of wind speed at ocean to land stations along Geojedo buoy line during 12∼13 Sep. 2003 affected by typhoon (MAEMI).

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.6
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• pp.647-653
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• 2016

There are no ex-port evaluations for the propriety and efficiency of AtoNs considering risk elements and environmental changes after the opening of a port. It is necessary to develop objective indicators and evaluation models to fill this gap. This study establishes an efficiency analysis model for Aids to Navigation (ANEffic) focusing on manned lighthouse, which include 20 function indices. After running a function assessment, an Analytic Hierarchy Process (AHP) and Likert scale are used to address port operations, national policies and expert opinions. As the result of the assessment, Yeongdo, Gageodo, Geomundo and Jukbyun Lighthouses are highly regarded in the propriety and efficiency of AtoN. And Uleungdo, Gasado, Songdaemal and Ulgi Lighthouses need to review detailed evaluations. The ANEffic developed should be utilized as basic tool to collect data for efficient management and to re-arrange the policy decisions regarding AtoNs as appropriate.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.335-343
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• 2014

Several species of the genus Pseudo-nitzschia produce the neurotoxin domoic acid (DA) known to be responsible for amnesic shellfish poisoning. Recently off the coast of Geomundo and in Exclusive Economic Zone (EEZ) of Korea Strait, P. cf. brasiliana predominated in summer, 2010. As P. cf. brasiliana was new to Korea, we describe the morphological characteristics of the species. It was observed that cells were linear to lanceolate in valve and girdle view, $51{\sim}76{\mu}m$ long and $1.9{\sim}2.6{\mu}m$ wide. In the central part a large interspace was absent. The number of fibulae and striae in $10{\mu}m$ were 30~37 and 31~37. Each stria contained 2~3 rows of poroids, with 10 to 14 poroids in $1{\mu}m$ length. These morphological features of P. cf. brasiliana were found to be similar with the P. brasiliana, except with the fact that P. cf. brasiliana carred more numbers of fibulae/striae in $10{\mu}m$ and poroids in $1{\mu}m$. Based on our observation, we suggest that P. cf. brasiliana is a newly identified Pseudo-nitzschia species or a variety of P. brasiliana.