• Ocean and Polar Research
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• v.29 no.3
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• pp.193-204
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• 2007

In order to find out the annual variations in the marine ecosystem of the East China Sea, temperature, salinity, nutrients, chlorophyll-a, suspended solids, and suspended particulate organic carbon were extensively investigated in the northern East China Sea during the Summer of 2003 and 2006. During the Summer of 2003, the northern East China Sea was not significantly affected by the input of fresh waters from the Changjiang River. During the Summer of 2006, however, fresh waters of the Changjiang River intruded into the western part of the study area where temperature, nitrate, and phosphate in the surface waters were higher than in the other areas, and salinity, silicate, and suspended solids in the surface waters were lower. As a result of the increase in nitrate and phosphate concentrations, concentrations of chlorophyll-a and suspended particulate organic carbon increased in the western part compared with the other areas. However, the depth-integrated chlorophyll-a concentrations measured during the Summer of 2003 were rather similar to those during the Summer of 2006, and not considerably different from those measured in the East China sea during the Summer of 1994 and 1998. Therefore, the depth-integrated chlorophyll-a concentrations have not significantly changed in the East China Sea over the last 12 years. The lower concentrations of silicate and suspended solids in the western part may be related to construction of the Three-Gorges Dam since the concentrations of silicate and suspended solids in fresh waters of the Changjiang River have significantly decreased after construction of the Three-Gorges Dam in June 2003.

• Analytical Science and Technology
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• v.20 no.3
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• pp.227-236
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• 2007

This study was carried out to estimate the contents of heavy metals (Hg, Pb, and Cd) in seaweeds (n=169) which are closely related to food resources. The contents of heavy metals in the laver were found as follows; Hg was highly detected in the east coastal area ($0.0509{\pm}0.0635mg/kg$), Pb in the south coastal area ($0.0509{\pm}0.0635mg/kg$), Cd in the south coastal area ($1.3785{\pm}0.7754mg/kg$). In the sea mustard, Hg was highly detected in the south coastal area ($0.0152{\pm}0.0116mg/kg$), Pb in the east coastal area ($0.1633{\pm}0.2888mg/kg$), Cd in the south coastal area ($0.7141{\pm}0.4952mg/kg$). In the sea tangle, Hg was highly detected in the south coastal area ($0.0177{\pm}0.0118mg/kg$), Pb in the east coastal area ($0.0728{\pm}0.1025mg/kg$), Cd in the south coastal area ($0.1640{\pm}0.1253mg/kg$). In the sea lettuce, Hg, Pb, and Cd were highly detected from the west coastal area. In the fusiforme, Hg and Cd were highly in the west coastal area, Pb in the south coastal area. In general brown algae showed the highest level of Hg, Pb, and green algae showed the highest level of Cd Additionally, the significant correlation was observed between Hg and Cd (r=0.513, p<0.01), between Cd and Pb (r=0.420, p<0.05). The weekly average intakes of Hg, Pb and Cd from seaweeds takes about 0.17~10.30 % of PTWI (Provisional Tolerable Weekly Intakes) that FAO/WHO Joint Food Additive and Contaminants Committee has set to evaluate their safeties.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.480-488
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• 2021

The term residence time is defined as the time taken for substances in a system to leave the system and is a useful concept to explain the physical environment characteristics of a coastal area. It is important to know the spatial characteristics of the residence time to understand the behavioral properties of pollutants generated in a marine system. In this study, the spatial distribution of average residence time was calculated for Gangjin Bay, Korea, using a hydrodynamic model including a particle tracking module. The results showed that the average residence time was about 10 days at the surface layer and about 20 days at the bottom layer. Spatially, this was the longest residence time in the southwestern sea. There was no significant difference in average residence time at the surface layer due to freshwater discharge, but spatial variation at the bottom layer was larger. The average residence time at the bottom layer decreased in the southwestern area due to freshwater discharge and increased in the northern area. This result suggests that the residence time of anthropogenic pollutants may have a large spatial difference depending on the freshwater discharge, and thus the time taken to influence cultured organisms may also vary.

• Journal of Environmental Impact Assessment
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• v.17 no.3
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• pp.167-176
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• 2008

Korea has made the rapid economical development under the condition with the high population density and low available land. In this context, conservation of land environment, connected directly with living quality of human, has mostly ignored. Prior Environment Review System(PERS) is the one to investigate the locational validity, environmental impacts, harmony with surrounding environment, from the early stage of administrative plan or development project. PERS was amended to include SEA(Strategic Environment Assessment) system on June 1, 2006. But, several problems, including the loss of administrative ability, cost, and time, have been appeared, since the system is applied to all administrative plans without any distinction and plans or projects are delayed generally. In this study, the weaknesses of PERS were indicated through the comprehensive analysis including literature survey, study of legal and internet database, and the recently published PERS reports. Based on that, the improvement schemes were suggested to be harmonized with the nature of SEA. This study was mainly focused on a PERS for the designation of conservational area of hot-spring wells, conducted by authors.

• Ocean and Polar Research
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• v.40 no.3
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• pp.127-143
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• 2018

This study analyzed the influence of climate change on the spawning ground area of the common squid, Todarodes pacificus. To estimate long term changes in the area of the spawning ground of the common squid, water temperature at 50 m deep that can be inferred from sea surface temperature (SST) based on both NOAA/AVHRR (1981.07-2002.12) and MODIS/AQUA (2003.01-2009.12) ocean color data was analyzed. In addition, five climate indices, Arctic Oscillation Index (AO), Siberian High Index (SH), Aleutian Low Pressure Index (ALP), East Asia Winter Monsoon Index (EAWM) and Pacific Decadal Oscillation (PDO) which are the main indicators of climate changes in the northwestern Pacific were used to study the relationship between the magnitude of the estimated spawning ground and climate indices. The area of the estimated spawning ground was highly correlated with the total catch of common squid throughout four decades. The area of the estimated spawning ground was negatively correlated with SH and EAWM. Especially, PDO was negatively correlated with the area of the spawning ground in the northwestern Pacific (r = -0.39) and in the southern part of the East Sea (r = -0.38). There was a positive relationship between the AO and the area of the spawning ground in the northwestern Pacific (r = 0.46) as well as in the southern part of the East Sea (r = 0.32). Temporally, the area of the winter spawning ground in the southern part of the East Sea in the 1980s was smaller than those areas in the 1990s and 2000s, because the area was disconnected with the western coastal spawning ground of Japan in the 1980s, while the area had been made wider and more continuous from the Korea strait to the western coastal water of Honshu in the 1990s and 2000s.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.2
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• pp.3-18
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• 2002

This study has been carried out to find the water Quality in coastal sea of fungmun area, southern Jeju Island. In-situ observations and water sampling had been made every month from July 1997 to June 2000. The distributions of water temperature and salinity over the study area have been 13.8~27.0℃ and 30.0~34.7‰, respectively. Salinity is showed low salinity from June to September (rainy season) because of rain. Tsushima Warm Waters (TWW) as ≥15℃ and ≥34‰ influence the adjacent sea around Jeju Island all year round. Yangtse Coastal Waters (YCW) influence the surface layer around Jeju from June to September and so strong stratification (termocline, halocline) resulted at the depth of between 20~30m at outer-sea. However the stratification does not happen even in summer at inner-sea, which seem to be caused due to vertical mixing by wind, waves and tides. A water mass of high value of water temperature and salinity (respectively 14.1~17.7℃, 33.9~34.1‰) stayed at the lower layer in outer-sea all the year round. It is probably formed by mixing between TWW and YSBCW(Yellow Sea Bottom Cold Water). The mean value of DO was the lowest in summer and the highest in winter. COD and TH were the highest in summer and the lowest in winter. However, TP showed the lowest value in summer season, because the mean value of N/P ratio was over 16. The mean of N/P ratio was under 16 in other seasons. The phosphate would be a limiting factor in the growth of phytoplanHon in summer. Nitrate would be a limiting factor in other seasons. Distribution of chlorophyll a did not show any seasonal change in the study period, but especially increased during April and May in the first year(1998) and the second year(1999) all over the study area, which suggested that phytoplankton inhabitation distributed widely in the study area. The space averaged values were the highest for TIN in rainy season and lower for TP in rainy season than in other seasons. It suggests that river runoff influences the inner-sea.

• Korean Journal of Environment and Ecology
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• v.31 no.6
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• pp.529-536
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• 2017

The study is intended to investigate the proliferation of whitening, the impact of climate change (sea temperature rise) on the proliferation of whitening, and the reproduction and growth of crustose coralline algae, which causes the whitening, in the coast of Jeju Island. The size of the whitening-affected area in the coast of Jeju was 2,931ha in 1998 and increased to 4,541ha in 2003. The whitening occurred mainly in the southern coast of Jeju in 1998 but spread across the whole coast of Jeju by 2003, except in the coast of Jocheon-eup (eup refers to an administrative district in Korea) and Gujwa-eup. The average sea water temperature in February from 1992 to 2004 was $15.1^{\circ}C$ in the whitening affected area and $13.9^{\circ}C$ in the marine forest area, showing a clear difference, but there was no difference in the average temperature in August. The long-term (37-year period) average of the sea temperature was $15.3^{\circ}C$ in the whitening affected area and $14.1^{\circ}C$ in the marine forest area, showing $1.2^{\circ}C$ higher in the whitening area. The annual rate of sea temperature rise was $0.038^{\circ}C$ in the whitening area and $0.024^{\circ}C$ in the marine forest area, indicating the higher long-term variation of sea temperature in the water affected by whitening. The results indicate that the continuous increase in winter water temperature due to climate change is expanding proliferation of whitening in the Jeju island.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.3
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• pp.354-365
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• 2019

Megabenthos samples were collected using 10-min trawls towed at 17 stations from 2015 to 2016. The dominant species (>1% of the total density) were Stegophiura sterea (10.4%) and two subtropical species, Mactrinula dolabrata (9.0%) and Acila divaricate (8.3%), respectively. The community structure of the megabenthos fell into four groups: the southeast, the southernmost region off Jeju Island, the frontal zone of the South Sea with C3, and a diagonal area from the south coast to the western side of Jeju Island. The total numbers of species, diversity, density and biomass were higher in the C3 region of the South Sea. Environmental factor analysis showed that differences in the megabenthos community were related to depth, gravel contents, and sorting value (${\sigma}$). These results indicate that changes in the marine environmental conditions in the South Sea of Korea affect the megabenthos species' composition and diversity.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.222-222
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• 2015

Vietnam is one of the most vulnarable countries affected by climate change and sea level rise. One of the consequences of climate change and sea level rise is the increase of salinity intrusion into the rivers which is challenging to irrigation systems in coastal areas. This indicates the necessary to study the ability of taking water through sluice gates of irrigation systems in coastal zones, especially in the dry season with the effects of climate change and sea level rise in the future. In this paper, Nam Thai Binh irrigation system is selected as a case study. The irrigation system is one of 22 biggest irrigation systems of the Red River delta in Vietnam located in coastal region. The computed duration is selected in dry season to irrigate for Winter-Spring crops. The irrigation water for the study area is taken from different sluice gates along the Red River and the Tra Ly River. In this paper, MIKE-11 model was applied to assess the ability of taking water for irrigation of the study area in current situation and in the context of climate change and sea level rise senario in 2050 (under the medium emissions scenario (B2) published by the Ministry of Natural Resources and Environment of Vietnam published in 2012) with different condition of water availability. The operation of the gates depends on the water levels and sanility conditions. The sanility and water level at different water intake gates of Nam Thai Binh irrigation system were simulated with different senarios with and without climate change and sea level rise. The result shows that, under climate change and sea water level rise, some gates can take more water but some can not take water because of salinity excess and the total water taking from the different gates along the rivers decrease while the water demand is increase. The study indicates the necessary to study quantitatively some recommended solutions in the study area particularly and in coastal region generally in Vietnam to ensure water demand for irrigation and other purposes in the context of climate change and sea level rise in the future.

• Journal of Environmental Impact Assessment
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• v.17 no.2
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• pp.97-103
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• 2008

This study presented politic proposals and diverse utilization-type in coastal areas by analyzing results of reviewed related-statements of marine environment during the one year period of 2007 by Marine Environmental Impact Assessment Center. Total of 358 cases were reviewed, which was a significant increase from 270 in 2006. Consultation on the utilization of sea areas (CUSA) accounted for the largest number of 165 (46.1%) and it was followed by 104 cases of environmental impact assessment (EIA) (29.0%) and 89 cases of prior environmental review (PER) (24.9%). As such, evaluation statements (EIA+PER) related to consultations of the Ministry of Environment accounted for approximately 54% of the entire cases reviewed. To analyze the overall results of reviewing marine-related evaluation statements, utilization and planning were conducted by 47.9%, 38.4% and 13.7% in the South Sea, West Sea and East Sea of Korea, respectively. In evaluation statements (EIA+PER), port construction, industrial complex construction, urban management plan and road construction took up most of the part by 40.9%, 20.2%, 10.4% and 7.3%, respectively. In terms of CUSA-statement, it was evaluated that consultations were mostly carried out on use and reclamation of public water surface in coastal areas and on sea aggregate extraction process in EEZ. The largest number of plans for coastal use were established for Jeollanam-do, followed by Gyeongsangnam-do, Chungcheongnam-do, Gyeongsangbuk-do and Gyeonggi-do. In particular, development plans were concentrated on Jeollanam-do and Gyeongsangnam-do with stable marine environment and outstanding view of the nature. In most cases, these regions are adjacent to the areas designated as a sea area for environmental management and fisheries resources protection zone. Therefore, conflicts exist between development and preservation. Also, rather than random development, more detailed marine environmental impact assessment, gathering of public opinions and politic harmony are essentially required. For efficient coastal management and environmentally sound and sustainable development, fulfilling consistent and transparent coastal policies as well as active and reliable decision making to center on coastal environment by management bodies will be important.