• Journal of The Geomorphological Association of Korea
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• v.27 no.2
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• pp.47-64
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• 2020

The Baengnyeongdo-island, located at the northernmost point of the west coast, has developed several coastal landforms. Although the coastal landforms of Baengnyeongdo-island are widely used as a tourism resource, a lot of academic research has not been conducted. In this study, particle size analysis, XRF, and OSL age dating were performed on the BR sandy deposits to find out the formation of coastal sand dunes on Baengnyeongdo-island. Based on the physicochemical properties, the BR section was divided into three parts; BR-A, BR-B and BR-C. First, about 56ka, which corresponds to the MIS 3, fine sand was deposited and forms the BR-C section. Second, the BR-B which located middle part of BR section, showed reversed age stratigraphy. The BR-B was interpreted as reworked sediments based on sedimentary facies and chemical weathering intensity. And, the BR-A composed of fine and medium sands was formed in middle Holocene. This research has significance in that it finds out the paleo sand dunes formed in Pleistocene. This study can contribute to understanding coastal sand dune development on the west coast.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.4
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• pp.315-326
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• 2015

Temporal and spatial variations of surface water temperature in Jinju Bay for the period of 2010~2011 were studied using the data from temperature monitoring buoys deployed at 17 stations in the south coast of Korea. Water temperature shows the maximum late in January and the minimum early in August. Seasonal variation of water temperatures at the north part of the bay is smaller than the middle and the south. In summer, the lowest and the highest of maximum water temperature are distributed around Jijok Channel which is located at the south of the bay. The fluctuations of water temperatures at Noryang and Daebang Channel are smaller than others because of vertical mixing caused by passage of strong tidal currents. Wind and strong currents affect on the stratification of the surface water layer near Daebang Channel. High temperatures come in frequently around the north area when eastward constant flows appear at neap tide as blowing westerly in the springtime at Noryang Channel. Spectral analyses of temperature records show significant peaks at 7~20 day periods at Noryang Channel, 7~20 day and semidiurnal at the west coast of Changsun Island and Jijok Channel and 7~20 day and diurnal at the middle of the bay. Temperature fluctuation at Noryang Channel shows high coherence and has leading phase with those at other stations in the bay. However, the phase of temperature fluctuation at Noryang Channel falls behind that at Daebang Channel. Daebang Channel has an influence on the temperature fluctuation only at the west and middle part of the bay. Cross-correlation analyses for the temperature fluctuation show that Jinju Bay could be classified into six areas; Noryang Channel, the area of convergence and divergence at the north, Daebang Channel, the west coast of Changsun Island, the mixing area at the middle of the bay and the south inside of the bay, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.112-117
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• 2017

Interest in the development of renewable energy sources has been increasing over the past 10 years and the west coast of Korea is one of the most favorable regions for tidal power. Barrage type tidal power is representative of the experience of installation and operation of such power sources for long periods. However, future projects for barrage type energy sources are either delayed or closed due to their environmental impact. For this reason, we applied a new tidal power technology with minimized environmental impact to a candidate area in the west coast and then analyzed its feasibility. The new tidal power technology is called Dynamic Tidal Power (DTP). Because its verification is impossible both in the laboratory and field, a numerical model is used for the evaluation of DTP. This new technology produces tidal power by means of the phase difference caused by diffraction on both sides of a dike built tens of km away from the coast. Because DTP is theoretically able to almost double the tidal range, it is expected to be applicable to even a small tidal area. Unlike the barrage type, it has the advantage of reducing the environmental impact by not enclosing the sea water. The west coast of Korea is close to the metropolitan area and has a high tidal range and, thus, it is thought to be a suitable candidate for tidal power.

• Korean Journal of Environment and Ecology
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• v.17 no.3
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• pp.295-303
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• 2003

The tidal flat area of south and west coast consists of 2.4% of total land area of Korea. About 83% of tidal flat is located at the west coast, and the remaining tidal flat is located at the south coast. This tidal flat is also divided for administrative regions which are Gyeonggi Province(35.1%), Chungnam Province(12.7%) Jeonbuk Province(4.7%), Jeonnam Province(44.0%) and Gyeongnam Province(3.5%). The tidal flat of west coast of Korea is one of the most important stopover site for shorebirds on the East Asia-Australia Flyway. The tidal flat is used for feeding and resting place by migratory shorebirds. Generally, waterbirds including migratory shorebirds are considered as key species to show the superiority of wetland. By the criteria of Lamsar Convention in the basis of waterbird, at least 14 coastal wetlands in Korea have to be internationally important wetlands. The factors to affect the distribution of shorebirds at the certain tidal flat are closely related with 1) the distribution of benthic invertebrates, potential prey of shorebirds 2) the availability of roosting site 3) the size of tidal flat 4) the intensity of human disturbance. In this paper, we summarized the regional status of tidal flat of Korea and its conservation methods related with migratory waterbirds.

• Journal of the Korean Geographical Society
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• v.38 no.5
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• pp.659-666
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• 2003

This study is a comparative analysis on the variabilities of spring precipitation and atmospheric circulations of 500hPa surfaces between dry years and wet years over the Korean Peninsula. The distribution of variabilities of precipitation in spring are different from month to month. In March, the pattern is west-high and east-low, in April, north-high and south-low, in May, east-high and west-low respectively. In the distribution of 500hPa geopotential height anomaly, dry years of March show west-high and east-low pattern in that negative anomaly zones are formed around the Korean Peninsula and western coast of the northern Pacific Ocean, and positive anomaly zones are formed in the inland of East Asia centered on Siberia. Consequently, the Korean Peninsula and neighboring regions experience dry season when the zonal flows are strong with the positive anomaly zones of zonal components. On the contrary in the wet years the westerlies are weak since the pattern is east-high and west-low in which the positive anomaly zones are formed over the Korean Peninsula centered on the Aleutian Islands and western coast of the northern Pacific Ocean and the negative anomaly zones are formed in the inland of East Asia centered on Tibet Plateau and Siberia. The dry years of April and May show north-high and south-low patterns in that negative anomaly zones are found from the center of the northern Pacific Ocean to the eastern coast of East Asia, and the positive anomaly zones are found in the center of East Asia extending from Aleutian Islands to Tibet Plateau. On the contrary, in the wet years the patterns show south-high and north-low. This study identified not only that there are contrary atmospheric circulation patterms between dry years and wet years over Korean Peninsua in spring, but also there are different atmosphric circulation patterns between early and late spring.

• Journal of Marine Life Science
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• v.3 no.2
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• pp.59-66
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• 2018

The assessment of level of health of the tidal flats can be evaluate by health of organisms inhabit the tidal flats. It is possible to evaluate the precise health level of organisms inhabit the tidal flats using analysis of expression of biomarker genes. The purpose of this research is to evaluate the health of the tidal flats on the west coast using biomarker genes such as heat shock protein 70 (Hsp70), heat shock protein 90 (Hsp90), glutathione S-transferases (GST) and thioredoxin (TRX). These genes are stress, immune, and antioxidant related genes that can be used to look at the health of an organism through gene expression. In this study, we collected manila clam (Ruditapes philippinarum) in 8 analysis areas on the west coast. Expression of the genes was analyzed by RT-qPCR method. Results showed that, the expression of Hsp70, Hsp90, GST and TRX genes were differentially expressed in the 8 analysis areas. In particular, the expression of Hsp90 and GST or the expression of Hsp70 and TRX were similar. This means that there is a substance that reacts specifically to each gene. Therefore, I think suggest that the based on the results of physicochemical analysis, it can be selected genes suitable for analysis. These results suggest that Hsp70, Hsp90, GST and TRX were played roles in biomarker for assessment of the health of tidal flats.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.1_2
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• pp.65-75
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• 1973

Morphological variations of the Korean Oyster, Crassostrea gigas, were studied on the basis of the oyster samples collected from seven ecologically different areas in May and October of 1972 respectively. The sampling areas were Daecheon and Buan in the west coast, Namseong, Cha-myeon, Imyeong and Chubong in the south coast and Pohang in the east coast. The average sizes of the oysters of the west coast were smaller than those of the south coast as well as those of the east coast. The oysters of the east were largest in size, The oysters from subtidal habitats (Chubong and Pohang) had elongated shells and those from intertidal habitats (Buan, Namseong, Imyeong and Chamyeon) had slanted shells. The samples from subtidal habitats showed size variations depending on cultural methods applied. The oysters from Chubong reared by hanging method had their shells as compared to those from Pohang reared by bottom culture method. The ratio of shell height to shell length showed a great variation froms areas to areas with a significant differences. The fatness (meat weight / shell weight) of all the samples collected in October revealed higher value than those collected in May. The oysters from Chubong showed maximum fatness, and those of Pohang showed minimum fatness. Seasonal variations in fatness was not significant in Chubong. On the other hand, it was relatively significant in the oysters from Pohang, Chamyeon, Imyeong and Buan. Water content of the oyster meat was greater in October than in May. It also showed variations in the sampling areas with higher values in the oyster from Imyeong and Chamyeon than those from Chubong, Pohang and Daecheon.

• Journal of Aquaculture
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• v.18 no.4
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• pp.252-259
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• 2005

Isozyme and AFLP analyses were examined to estimate the utilities of them as a genetic marker. The utilities were evaluated by genetic divergence and relationships among the four distinct abalone species; Haliotis discus hannai collected from northeast coast of Japan and Yellow-Sea coast of China, H. rufescens collected from west coast of USA, H rubra collected from southeast coast of Australia and H midae collected from Cape Town of South Africa. Isozyme and AFLP analyses showed a clear genetic divergence between every pair of species. Genetic relationships among the low species estimated by isozyme and AFLP analyses reflected to geographical distribution and morphological characteristics. In conclusion, Isozyme and AFLP analyses are suitable genetic markers far estimates of genetic divergence and relationship among abalone species.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.4
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• pp.322-339
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• 2020

Temporal and spatial fluctuations of surface water temperature in Yeosu Bay for the period from 2010 to 2011 were studied using the data from temperature monitoring buoys deployed at 32 stations in the south coast of Korea. Temperatures in the northern part of the bay are higher in summer and lower in winter than in the southern part of the bay. The lowest and highest temperature of the annual mean are found at the eastern coast of POSCO and at the west of Dae Island, respectively. Cold water masses appear at estuarine area when the discharge of Sumjin river is affluent. Amplitude of temperature fluctuation whose period is less than semi-diurnal is largest at Hadong coast and around Dae Island. Spectral analysis of surface water temperature shows a significant peak at a periodic fluctuation of 0.5 to 24 days and about 15-day period of predominant fluctuation is most frequent in Yeosu Bay. From the cross-correlation analysis of temperature fluctuations, Yeosu Bay can be classified into six areas; the south area affected by South Sea of Korea, the mixed area in the center of the bay, the estuarine area affected by river discharge at the north of the bay, the hot waste water area near Hadong coast, the area around Dae Island and the area near Noryang Channel affected by the water in Jinju Bay, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.659-664
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• 2010

This study investigated the distribution of spotted seals, Phoca largha, inhabiting the coast of Baekryongdo. Monitoring of spotted seals in Baekryongdo was conducted between June 2006 and November 2008, using a 5-ton fishing vessel 1hour before low tide. The monthly maximum number of observed seals was 274 in September 2006, 139 in September 2007, and 213 in August 2008. Average observed monthly counts were largest in August and September. Relatively more spotted seals were observed when there were few cloudy days and plenty of sunshine. Bycatch, stranding, and observations of spotted seals have been reported along the coast of the Korean peninsula since 2000, and spotted seals were observed four times in the western coastal region, three times in the southeastern region, and 12 times on the east coast. This suggests that spotted seals inhabiting Baekryongdo migrate to the East Sea via the West and South seas as individuals or in groups.