• Journal of the Korean Society of Marine Environment & Safety
• /
• v.18 no.1
• /
• pp.15-24
• /
• 2012

This study aims to investigate characteristics of water quality factors by using survey results of national marine environmental monitoring system from 2004 to 2010 at coastal area of the East Sea of Korea. In this study, we chose statistical methods to analyze the correlation among water quality parameters and principal component analysis for characteristics of each water environment. In addition to this, we evaluated each water's pollution level based on eutrophication standard of OECD, Eutrophication Index(EI), and Organic Pollution Index(OPI). Major factors were chlorophyll a and salt according to the analysis at coastal area of the East Sea. The sea was divided into the south and the central part by Jukbyeon. Also, Jukbyeon in the central part of the East Sea and Gampo in the southern sea coastal waters have been classified separately. The nutritional status of coastal area of East Sea presented Mesotrophic to Oligotrophic level and EI showed less than 1. OPI in all of the coastal area at the East Sea represented that the water quality condition was favorable.

• Journal of the korean society of oceanography
• /
• v.39 no.4
• /
• pp.212-221
• /
• 2004

Concentrations of suspended particulate matters (SPM) and their distribution patterns were monitored three times in the East China Sea during the winter season in 1998 and 1999. SPM concentrations showed significant temporal variations controlled by the atmospheric conditions and sea states. In coastal area, SPM values were about 10-20 mg/l in fair weather conditions, but exceeded 100mg/l during the storm periods. Turbid waters were distributed widespread in the continental shelf of the East China Sea and the coastal area of the Korean Peninsula, and these two areas were connected along a NE-SW direction. The distribution patterns of turbid waters were interpreted as representing the transport behavior of suspended matter. Although the primary source of inner shelf mud deposits of Korea seems to be the Korean Peninsula, contribution from the East China Sea to the coastal area of Korea increases especially during the winter season.

• Journal of Environmental Science International
• /
• v.19 no.12
• /
• pp.1385-1395
• /
• 2010

Harmful dinoflagellate Cochlodinium polykrikoides blooms have been frequently occurred in coastal areas of the East Sea since 1995. We compared the oceanic conditions in years 1995, 2001 and 2003 when the C. polykrikoides bloom was strong, and in years 1998 and 2004 when the C. polykrikoides bloom was not appeared. We studied temporal and spatial variation of upwelling and geostrophic currents on the western channel of Korean Strait, an entrance of the East Sea. The period and occurrence area of C. polykrikoides bloom was depended on variation of upwelling in summer. In the distributions of geostrophic current, southward current was dominant near the coast in August, 1998 and 2000. Whereas northward current was dominant near and off the coast in August, 1995 and 2003 which the C. polykrikoides bloom was strong. When compared dominant phytoplankton of the coastal areas in each year, Kuroshio indicator species Proboscia alata and Chaetoceros affine were dominant, respectively, in 2001 and 2003 at every stations. However, the dominant species was variable at each coastal area in 1998 and 2000. In 2003, the abundance of Sagitta elegans which is known as the cold water indicator was low, but the abundance of S. enflata, warm water indicator, was very high in Gangneung compared to Sokcho. It seemed that the distribution of S. elegans is restricted by strong warm water current. In conclusion, it was estimated that the distribution of C. polykrikoides bloom in the coastal area of the East Sea was closely related with the strength of East Korea Warm Current and upwelling.

• Proceedings of KOSOMES biannual meeting
• /
• 2003.11a
• /
• pp.219-225
• /
• 2003

The present study intends to assess the long-term steric sea-level change and its prediction, and potential impacts to the sea-level rise due to the 21st global warming in the coastal zone of the Korea in which much socioeconomic activities have been occurred. The analysis of the 23 tide-gauge data near Korea reveals the overall mean sea-level trend of 2.31 mm/yr.In the satellite altimeter data (Topex/Poseidon and ERS), the sea-level trend in the East Sea is 4.6mm/yr. Both are larger than those of the global average value. However, it is quite questionable that the sea-level trends with the tide-gauge data on the neighboring seas of Korea relate to global warming because of the relatively short observation period and large spatial variability. It is also not clear whether the high trend of altimeter data in the East Sea is related to the acceleration of sea level rise in the Sea, short response time of the Sea, natural variability such as decadal variability, short duration of the altimeter. The coastal zone of Korea appears to be quite vulnerable to the 21st sea level rise such that for the I-m sea level rise with high tide and storm surge, the inundation area is 2,643 km2, which is about $1.2\%$ of total area and the population in the risk areas of inundation is 1.255 million, about $2.6\%$ of total population. The coastal zone west of Korea is appeared to be the most vulnerable area compared to the east and south. In the west of the Korea, the North Korea appears to be more vulnerable than South Korea. In order to cope with the future possible impact of sea-level rise to the coastal zone of Korea effectively, it is essential to improve scientific information in the sea-level rise trend, regional prediction, and vulnerability assessment near Korean coast.

• Proceedings of the KSRS Conference
• /
• v.2
• /
• pp.918-921
• /
• 2006

The short-term variation of sea surface temperature before and after typhoons and increase of chlorophyll a concentration that accompany with the typhoons during summer in the East/Japan Sea were explored by satellite. Four typhoons (NAMTHEUN, MEGI, CHABA and SONGDA) and a typhoon (NABI) passed over the East/Japan Sea in 2004 and 2005, respectively. Decreasing of SST was observed in the every five typhoons, however the magnitude of SST decreasing were various from 1 to $5^{\circ}C$. Chlorophyll a increases were found after the typhoons (0.1-3 ${\mu}g$ $l^{-1})$ except NAMTHEUN, and the area was approximately included in SST decreasing area by the typhoons. It suggests that chlorophyll a increase was caused by nutrient input from subsurface layer by strong mixing. On the other hand, rarely chlorophyll a increase was observed in northern area of polar frontal zone, which is located in $38-41^{\circ}N$, than northern area, and chlorophyll a increase in coastal area was higher (more than 3 times) than offshore area. It might suggest that chlorophyll a increase in the East/Japan Sea is also related with the depth or nitracline depth that affects the amount of nutrients supply to the upper layer by typhoon mixing.

• Journal of the korean society of oceanography
• /
• v.37 no.3
• /
• pp.187-195
• /
• 2002

The characteristics of surface circulation in the Yellow Sea and the East China Sea are discussed by analyzing a great deal of current data observed by 142 sets of mooring buoy and 58 sets of drifters trajectories collected in the Yellow Sea and the East China Sea through domestic and abroad measurements. Some major features are demonstrated as bellow: 1) Tsushima Warm Current flows away from the Kuroshio and has multiple sources in warm half year and comes only from Kuroshio surface water in cold half year. 2) Taiwan Warm Current comes mainly from the Taiwan Strait Water in warm half year and comes from the intruded Kuroshio surface water and branches near 27N in cold half year. 3) The Changjiang Diluted Water turns towards Cheju Island in summer and flows southward along the coastal line in winter. 4) The study sea area is an eddy developing area, especially in the southern area of Cheju Island and northern area of Taiwan.

• Journal of the Korean earth science society
• /
• v.39 no.2
• /
• pp.154-163
• /
• 2018

Geoacoustic model comprises physical and acoustic properties of submarine bottom layers influencing sound transmission through sea water and underwater. This study suggested for the first time that we made a geoacoustic model of long-coring bottom layers at the SSDP-105 drilling site of the Ulsan coastal area, which is located in the southwestern inner shelf of the East Sea. The geoacoustic model of 52 m depth below seafloor with three-layer geoacoustic units was reconstructed in the coastal sedimentary strata at 79 m in water depth. The geoacoustic model was based on the data of a deep-drilled sediment core of SSDP-105 and sparker seismic profiles in the study area. For actual modeling, the geoacoustic property values of the models were compensated to in situ depth values below the sea floor using the Hamilton modeling method. We suggest that the geoacoustic model be used for geoacoustic and underwater acoustic experiments of mid- and low-frequency reflecting on the deep bottom layers in the Ulsan coastal area of the East Sea.

• Fisheries and Aquatic Sciences
• /
• v.3 no.1
• /
• pp.8-13
• /
• 2000

Monthly mean chlorophyll concentration in the East Sea was estimated from the ocean color observed by the Coastal Zone Color Scanner (CZCS) on Nimbus-7 satellite which had performed various remote sensing missions from 1979 to 1986. The areas of high chlorophyll concentration were found in the sea between Siberia coast and Sakhalin Island, in the Donghan Bay and in the Ulleung Basin. In the southwestern East Sea, especially in the area near Ulleung Island, the yearly maximum chlorophyll concentration occurred in December. The chlorophyll concentration in Ulleung Basin in December was about two times higher than during spring bloom in April. The early winter bloom occurred in the warm side of the front that was formed between warm water from the East China Sea and nutrition rich cold water from the northern East Sea.

• Journal of Climate Change Research
• /
• v.9 no.4
• /
• pp.369-376
• /
• 2018

Korea is surrounded by the West Sea, the South Sea, and the East Sea. There are various points at which large and small rivers flow into the sea, and areas where these rivers meet the coast are vulnerable to disasters. Thus, it is necessary to study disaster prevention techniques based on coastal characteristics and the pattern of disasters. In this study, we analyzed the risk factors of disaster districts analyzed in comprehensive plans for the reduction of damage to coastal cities from storms and floods. As a result of standardization, four factors (tide level, intensive rainfall & typhoon, wave, and tsunami) were identified. Intensive rainfall & typhoon occurred along the West Sea, the South Sea, and the East Sea coast. Factors that should be considered to influence disasters are tide level for the West Sea, tsunami and tide level for the South Sea, and wave in the East Sea. In addition, disaster prevention techniques to address these factors are presented, focusing on domestic and overseas cases.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.6
• /
• pp.1037-1054
• /
• 2014

In this study, the status of coastal fisheries was examined based on the catch and number of fishing vessels of coastal fisheries in Korea. Comparing the status on coastal fisheries of the East Sea, Yellow Sea and South Sea in Korea, scientific evidence was made for fisheries management on coastal fisheries based on characteristics of each sea area. From 1990 to 2011, the catch of coastal fisheries in Korean waters ranged from 150,000 mt to 230,000 mt, with an average of 190,000 mt, and it accounted for 15% in average of total catch fished in adjacent waters of Korea. In order of catch by coastal fisheries, gillnet (36.7%) was the primary fishery, followed by coastal complex (24.7%), stow net (18.3%), trap (12.9%), lift net (3.9%), purse seine (3.0%) and beam trawl (0.4%) fisheries. In order of catch by species, anchovy (15.0%) had the largest proportion of total catch, followed by common squid (10.3%), akiami paste shrimp (5.2%), blue crab (3.9%) and octopus (3.7%). Of the average catch by sea area from 1990 to 2011, Yellow Sea, South Sea and East Sea were 37.4%, 34.6% and 28.0%, respectively. Since 2000s, however, the average catch of South Sea has accounted for the largest proportion. The number of permitted fishing vessels involved in 8 coastal fisheries was 55,336 vessels in average from 1997 to 2011. The number of vessels was about 47,000 vessels in 1997, and increased to 61,300 vessels until 2000, then has decreased to 44,000 vessels operating in 2011. In order of the number of permitted fishing vessels by fisheries, complex (52.4%) took the first place, followed by gillnet (31.5%), trap (13.4%), stow net (0.8%), beam trawl (0.8%), purse seine (0.6%), lift net (0.4%) and seine net (0.0%). In order of the number of permitted fishing vessels by sea area, South Sea (29,994 vessels) took the first place, followed by Yellow Sea (18,185 vessels) and East Sea (7,158 vessels). In order of the catch per unit effort (CPUE, mt/vessels) which was analyzed using catch and number of vessels in average by fishery, stow net is the highest followed by lift net, trap, purse seine, gill net, beam trawl and complex fisheries. In particular, the CPUE of complex and gill net fisheries, which accounted for the largest number of vessels were 4.0 mt/vessels and 1.6 mt/vessels, respectively. Since those are too low relative to other fisheries, it was judged to need systematical management on both fisheries.