• Korean Journal of Fisheries and Aquatic Sciences
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• 제42권1호
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• pp.68-72
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• 2009

To gain a greater understanding of the potential for future harmful algal bloom (HAB) outbreaks and to trace the dispersal paths of dinoflagellates, sediment samples were collected from 13 stations in the southeastern Yellow Sea. 23 different types of dinoflagellate resting cysts were identified from the samples. Protoceratium reticulatum (1-391 cells/g dry weight), Gonyaulax scrippsae (0-254 cells/g dry weight), G. spinifera (0-301 cells/g dry weight) and Alexandrium spp. (ellipsoidal type) (0-76 cells/g dry weight) were the dominant species at all surveyed stations. The overall distribution pattern demonstrated that the resting cyst densities were highest in the offshore area and decreased gradually toward the Korean coast. On the other hand, the composition rate of resting cysts of the heterotrophic dinoflagellate species to the total dinoflagellates was higher in the Korean coast region than in the offshore area. We supposed that this distribution pattern of dinoflagellate resting cysts appeared to be influenced by the hydrographic features and environmental conditions of the Yellow Sea.

• Journal of Environmental Science International
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• 제12권12호
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• pp.1293-1301
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• 2003

A species of facultative photo-organotrophic, purple, non-sulfur bacterium was isolated from the 47 point at west and south coast of Korea in September 2001. Separated 13 samples of changes with red color under 28-32$^{\circ}C$, 3000 lux, anaerobe conditions for 7 days cultivated in basal medium. For pure isolation from 13 samples, we used agar-shake tube method (0.4 ％ agar) and separated 5 strains through 13-repetition test. EGH-24 and EGH-30 was identified as the same strain through the RAPD(Random Amplified Polymorphic DNA)-PCR of strain EGH-9, EGH-13, EGH-23, EGH-24, EGH-30. Four isolates cultivated in synthesis wastewater for wastewater biodegradation test. EGH-24 was selected with efficient wastwater treating strain. Based on the results obtained from morphology, nutrient requirements, major bacteriochlorophyll content, 16S-rDNA phylogenetic analysis, EGH-24 strain may be identified as a new strain of the genus Rhodobacter and named Rhodobacter sp. EGH-24.

• Proceedings of the Korean Geotechical Society Conference
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• 한국지반공학회 2000년도 토목섬유 특별세미나
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• pp.61-69
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• 2000

It is not easy to find a good soil condition due to the shortage of suitable land for construction work. The earth structure and buildings can be constructed over the soft soil. The soft soil must be treated either using the reinforcement element or dewatering. Most of land reclamation projects are being implemented along the south coast or west coast of the Korean Peninsula. The soils in these areas are covered with the soft marine clay, so soil and site improvement is the most important things to do. Pile foundation at the bottom of embankment can be constructed either in the soft ground or in the soil contaminated area. The purpose of this research is to develop "geogrid-reinforced piled embankment method" to prevent the differential settlement and increase the bearing capacity of soil. In this study, the effectiveness of the geogrid-reinforcement was studied by varying the space between piles and reinforcement conditions. Also, the geotechnical engineering properties of the embankment material and foundation soil were determined through the laboratory tests as well as the field tests. As a result, the site that the pile-spacing S = 3b with geogrid reinforcement is the most effective to reduce the differential settlement and increase load bearing capacity.

• Ocean and Polar Research
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• 제31권4호
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• pp.415-422
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• 2009

The wave observation system in Korea has been established with an emphasis on pointmeasurement based on in situ instrumentations. However, the system cannot fully investigate the coastal wave-related problems that are significantly localized and intensified with three-dimensional regional geometries. Observation technique that can cover local processes with large time and spatial variation needs to be established. Video imaging techniques that can provide continuous monitoring of coastal waves and related phenomena with high spatial and temporal resolutions at minimum cost of instrumentation risks are reviewed together with present status of implementation in Korea. Practical applications of the video imaging techniques are suggested to tackle with various coastal issues of public concern in Korea including, real-time monitoring of wave runup and overtopping of swells on the east coast of Korea, longshore and rip currents, morphological and bathymetric changes, storm surge and tsunami inundation, and abnormal extreme waves in the west coast of Korea, etc.

• Ocean and Polar Research
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• 제31권3호
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• pp.277-282
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• 2009

Saunders' gulls (Laurs saundersi) which are listed as globally vulnerable species on the IUCN Red List are distributed in East Asia and breed mainly in China and Korea. Their population is estimated to be between 7,100 to 9,600. Songdo reclaimed lands in the western coast of South Korea are the main breeding sites for these species. However, most of these breeding sites have been seriously disturbed in the last several years because of new urban development constructions. This study was conducted to provide baseline data on the breeding ecology of Saunders' gulls. Since 1998, the breeding population has rapidly increased in South Korea, with the number of nests rising from 85 nests in 2000 to 185 nests in 2005. Egg volume is more variable than breadth or length. Clutch size, hatching and breeding success were $2.9{\pm}0.81$ (n=182, mean$\pm$sd.), 48.07% (75 hatched egg/156 eggs) and 29.08% (155 fledglings/533 eggs), respectively. Factors affecting breeding failure were predation, rainfall, starvation and supernormal clutches. These results are provided along with other cited literature to argue for conservation of Saunders' gulls.

• The Korean Journal of Quaternary Research
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• 제9권1호
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• pp.43-60
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• 1995

The Kanweoldo Deposit in the Cheonsoo Bay western coast of Korean Peninsula is considered to be influenced by severe freezing condition under cold humid environment of the last glacial age. The evidence of severe freezing in the some upper part of the fine-grained Kanweoldo Deposit is characteristically irregular wavy la-mellar structure with the interval of 2∼8mm. In particular lamina show very compacted fabrics composed of rounded or spheroidal discrete aggregates covered by silt caps. Such laminar structure and associated micro-fabrics might owe to soil freezing such as ice segregation in lens form cryophoresis pressure from growing ice and disturbance by frost-creep. Furthermore pedogenesis of cold-humid type such as gleyzation or peseudo-gleyzation also might af-fect the kanweoldo Deposit in the priod of severe cold-humid cli-mate of the Wrm. The Kanweoldo sediment and organic remnant(16,708 B.P. with error limit of 250 years) affected by severe cryogenic activities sug-gest that the paleoclimate of Late Wrm in Korea might be so cold and humid as to engender the cryogenic structure in subaerial silty and sandy silt deposits.

• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.295-301
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• 2011

We investigated the genetic structure of Korean and Japanese ayu Plecoglossus altivelis populations by examining 669 individuals from 14 populations using three microsatellite loci. Genetic variation did not differ significantly among the populations examined in terms of allelic number and heterozygosity. Korean populations were genetically close to each other, implying that persistent gene flow has occurred in these populations. This suggests that eastern populations in Korea form a single large population and all of the Korean populations are distinct from the Japanese populations. Pairwise population $F_{ST}$ estimates, principal component analyses, and a neighbor-joining tree showed that genetic separation between the southern and pooled eastern coast populations was probably influenced by restricted gene flow. Hierarchical analysis of molecular variance (AMOVA) revealed a weak but significant genetic structure among three ayu groups (eastern and southern coasts of Korea and the Japan coast), and no genetic variation within groups. The estimated genetic population structure and potential applications of microsatellite markers may aid in the proper management of ayu populations.

• Korean Journal of Environmental Biology
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• 제25권4호
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• pp.297-302
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• 2007

An investigation of fish fauna was conducted based on the specimens from the Taean International Marine Park, off West Coast of Korea in 2005. They were collected by small seine net and stake net. The collected fishes were composed of 27 species belongs to 15 families and 8 orders. The dominant species were gobids of Favonigobius gymmnauchen in the sand area, Chamichthys gulosus and C. dolichognathus in the rocky area. The Korean endemic species were two species of Zoarchias uchidai and Repomucenus koreanus. But Porocottus leptosomus that described as a new species on the basis of specimens collected from this area in 2002 was not collected in this study.

• Magazine of the Korean Society of Agricultural Engineers
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• 제45권3호
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• pp.103-115
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• 2003

This study examines groundwater movement system analysis and movement forecast algorithm using finite element method. The target is Cheongha-myeon area, Bukgu, Pohang-city which has many difficulties in water supply during drought period. From the comparison of the differences between obtained values by WINFlOW model and observed values, it is thought that groundwater head distribution under steady flow is reflected well at the level of reliability Groundwater movement of study area shows stable pattern from western watershed to eastern coastal area while flow path is dense and steep in the center of the coastal area. The results of particle tracing for each well show a comparatively straight line from the western boundary side to the observation position at the upper area of the well, and are analyzed as it diffuses according to getting closer to the coast at the lower area of the well. The result of effect circle examination attendant on pumping amount in study area shows variation tendency that groundwater head decreases at the side and the lower area more than at the upper area of the well when groundwater flows from west to east(coast). As mentioned above, satisfactory results of groundwater movement analysis using WINFlOW model, two dimensional groundwater movement analysis model, are obtained through the great decrease of physical uncertainty of groundwater movement system.

• Food Science and Biotechnology
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• 제18권2호
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• pp.367-373
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• 2009

Regional variation in the fatty acid content of shellfish was investigated on 5 species of Korean shellfish including murex shell, ark shell, jack-knife clam, orient hard clam, and little neck clam that were originated from 2 geographically different regions in Korea (Region 1: South coast, $34-35^{\circ}N$, $127-129^{\circ}E$; Region 2: West coast, $36-38^{\circ}N$, $126-127^{\circ}E$). Significant regional difference in total fatty acids content was observed in murex shell and little neck clam (p<0.01), but not in the other species of shellfish. The contents of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids including n-3 and n-6 fatty acids were appreciably higher in murex shell from Region 2 and in little neck clam from Region 1 than the shellfish originated from their counterpart areas (p<0.05). Nevertheless, relative percentages of the fatty acids remained constant within same species regardless of geographic regions or species. Considering the facts of that the fish/shellfish are unique sources of n-3 fatty acids and a little neck clam is the most-consumed shellfish in Korea, n-3 fatty acids intake might vary with the habitat of the shellfish that Koreans consume.