• Proceedings of the Korean Society of Toxicology Conference
• /
• 2006.05a
• /
• pp.77-81
• /
• 2006

• 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.

• Journal of The Geomorphological Association of Korea
• /
• v.23 no.1
• /
• pp.129-140
• /
• 2016

Camera monitoring data for 5 years from January 2009 to January 2014 are analyzed to investigate changes in beach erosion on Sangju, Gujora and Haeundae beaches on the South sea and Jungmun beach on the south shore of Jeju Island. The data show the time series of beach area changes obtained from digital orthoimages rectified from oblique images taken near the beaches by cameras. Each beach has different sediment sizes and shapes, but faces the South and is eroded mainly during Typhoons. However, each beach often responds differently to the same Typhoon, and some beaches outside the influence of the Typhoon are also eroded. This study shows that high frequency data of beach area changes obtained from cameras can effectively analyze the seasonal changes in beach area.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.53 no.4
• /
• pp.437-445
• /
• 2017

Distribution and composition of the seabed litters in the exclusive economic zone of the West Sea of South Korea including 18 sea-blocks were investigated using a bottom trawl gear of the R/V Tamgtu 20 (National Institute of Fisheries Science) from 24th April 2011 to 4th May 2012. Each trawl shot was conducted for an hour in each sea-block and the total trawl shots was 18. As a result, 325.6 kg of seabed litter in total has been collected. The quantity of the seabed litter was highest at No. 202 of the sea-block, close to the Heuksan-Do. The highest occupied sea material was plastic (83.1% of entire seabed litters), the second highest material was metal combined with plastic (10.6%), and glass (2.9%), metals (2.3%), vinyl (0.6%), cloth (0.4%) and wood (0.2%) in order. The origin of seabed litters was from fishing gear (89.0% of all seabed litters). Therefore, it could be assumed that most seabed litters were derived from the fishing activity for example fishing nets and ropes.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.5
• /
• pp.590-597
• /
• 2022

We analyzed the diet composition of smallmouth argentine Argentina kagoshimae, which were collected via bottom trawl in the South Sea during February, April, August, and October 2021. Their size range was 8.1-21.4 cm total length. A. kagoshimae are mesopelagic carnivores, mainly consuming benthopelagic Euphausiacea and Caridea crustaceans. Polychaetes were the second largest prey component in their diet, which also included small quantities of copepods, amphipods, and arrow worms. Stomach content compositions substantially differed among body size levels in A. kagoshimae. The results of non-metric multidimensional scaling ordination and permutational multivariate analysis of variance of dietary data revealed no significant dietary differences. The results of a graphical analysis of the diet composition showed that A. kagoshimae are specialized feeders characterized by strong individual feeding specialization.

• Ocean and Polar Research
• /
• v.33 no.2
• /
• pp.99-111
• /
• 2011

To estimate the effects of limitation nutrients for phytoplankton growth and its influences on short-term variations of a winter phytoplankton community structure, we investigated the abiotic and biotic factors of surface and bottom waters at 20 stations of inner and offshore areas from 6 to 7 February in Gwangyang Bay, Korea. Also, several algal bio-assay studies were conducted to identify any additional nutrient effects on phytoplankton assemblage using surface water for the assay. The dominant species in the bay was diatom Skeletonema costatum, which occupied more than 70% of total species in most stations (St.1-16) of the inner bay. According to a cluster and multidimensional scaling (MDS) analysis based on phytoplankton community data from each station, the bay was divided into three groups. The first group included stations from the south-western parts of Myodo lsland, which can be characterized as a semien-closed eutrophic area with high phytoplankton abundance. The second group included most stations from the north-eastern part of Myodo lsland, influenced indirectly by surface water currents from offshore of the bay. The standing phytoplankton crops were lower than those of the first group. The other cluster was restricted to samples collected from offshore of the bay. In the bay, silicon (Si) and phosphorus (P) were not a major limiting factor for phytoplankton production. However, since the DIN: DIP and DSi: DIN ratios clearly demonstrated that there were potential stoichiometric N limitations, nitrogen (N) was considered as a limiting factor. Based on the algal bio-assay, in vivo fluorescence values in N (+) added experiments were higher compared to control and P added experiments. Our results suggested that nitrogen may act as one of the most important factors in controlling primary production during winter in Gwangyang Bay.

• Korean Journal of Plant Taxonomy
• /
• v.39 no.1
• /
• pp.55-57
• /
• 2009

Here we report the occurrence of a seagrass species, Halophila nipponica J. Kuo, which was recently collected from Ando-ri, Yeosu-city, Jeollanam-do in Korea. H. nipponica, which was first collected from Japan, is the only Halophila species distributed in temperate regions, and was reported as a new species recently. The new Korean common name of this species, 'Hae-ho-mal' was given considering its habitat.

• Ocean and Polar Research
• /
• v.32 no.4
• /
• pp.351-359
• /
• 2010

This study examined extensive patches of floating green macroalgal (Ulva prolifera) mats in the northern East China Sea (ECS) using satellite images from mid May through July 2008 and field observation made during early August 2008 cruise. It was previously reported that the massive macroalgal blooms occurred in the coastal areas of Qingdao in China. During our field survey, researchers noticed widely distributed floating patches of macroalgal mats ranging in size from tens of centimeters to a few hundred meters in diameter. Meteorological data in the northern ECS showed high irradiance, high air-temperature, and predominant southerly winds in summer. In the study area during the survey period, surface waters were characterized by the Changjiang Diluted Water (CDW) mass, which contained high concentrations of nitrate and phosphate. The internal transcribed spacer (ITS) sequence of U. prolifera found in the northern ECS was the same as those of U. prolifera sampled from Qingdao blooms, suggesting a possibility that U. prolifera found in two regions would be derived from the same origin. We suggest that U. prolifera in the nearshore Jiangsu Province drifted into the northern ECS and proliferated under favorable meteorological and oceanographic conditions during the summer of 2008.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.22 no.4
• /
• pp.165-169
• /
• 2012

It is very difficult to detect irradiated South Sea cultured pearls (SSCPs) at a low dose by gemological methods (e.g. optical transmission method, microscopic examination, UV fluorescence reaction, and so on). In this study, however, it was possible to distinguish between irradiated SSCPs from un-irradiated SSCPs by ESR analysis. We have analyzed the pearl nacre and nucleus by separating them for the purposed of providing information about the change of $CO^-_2$ radical as growing absorbed doses. And it was found out that the signal of $CO^-_2$ radical of the nacre is more distinct than the nucleus.

• Maritime Security
• /
• v.3 no.1
• /
• pp.115-140
• /
• 2021

The South China Sea is a significant maritime shipping route with abundant submarine and fishing resources. Over 40,000 ships pass through the South China Sea every year, constituting around 50% of global shipping and 66% of crude oil. In particular, 30% of Korea's import cargo and 90% of energy imports pass through this body of water. The US and China realized the significance of this sea area from early on and are embodying national interest through maritime security at the national strategic level by implementing the 'Indo-Pacific' and 'One Belt One Road' strategies, respectively. Such geopolitical conflicts are manifested in the 'freedom of navigation operations' by the US in the South China Sea. Despite its significance, there is a lack of studies in Korea on the freedom of navigation operations, and most previous studies only focus on analyzing international law and agreements. This article examines the origin and background of the strategic perception of the freedom of navigation operations and derives implications for the peace and security of the Korean Peninsula as the strategic competition between the US and China continues.