• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.268-278
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• 2001

To investigate sedimentary facies and environmental changes of the Nakdong River Estuary and its adjacent coastal area, the grain size analysis and measurement of organic matter, calcium carbonate, clay mineral and metallic elements were carried out for forty surface sediment samples. Based on regional distribution pattern and characteristics of the surface sediments, sedimentary facies in the study area can be divided into sand facies (TYPE I), mud facies (TYPE II) and sand-mud mixed facies (TYPE III). TYPE III is the transition of TYPE I and TYPE II in every aspects of sediment characteristics. It suggests that TYPE III may have been formed by the mixture of two different source of sediment : one derived from Nakdong River and the other resuspended fine-grained sediments from the Jinhae Bay by winnowing action during floods or storms. Among many aspects of environmental change after the construction of the Nakdong Barrage, the most significant is the increase of sand content off the sand barrier region. It could be explained by several reasons including decreased input of fine-grained sediment from river, increased hydrodynamic energy level off the sand barrier region and artificial effects such as dredging and dumping.

• 한국해양학회지
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• v.26 no.3
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• pp.193-203
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• 1991

KODOS (Korea Deep ocean Study)-89 sediments, recovered from western part of Clarion-Clipperton fracture zone in north Pacific, show two distinctly colored layer zones: surface yellow brown layer (unit A) and subsurface dark brown layer (unit B), and roughly recognized as Quaternary and Tertiary in age, respectively. Geochemical characteristics are also different in those two units. Smectite, water, micronodule, and heavy metal contents are higher in unit B, while POC content is higher in unit A. High smectite and low POC contents in unit B are due to the longer formation period of smectite, almost decomposition of labile organic matter in unit B relative to unit A. High water content in unit B is caused by coarse fabric which results from higher content of spicules and spines. Additionally, stronger electrostatic repulsion force caused by high smectite content also supports high water content in unit B relative to unit A. Variations in heavy metal contents are closely related to the amount of micronodule, which has higher metal contents than that of sediment. Therefore, we conclude that the differences of geochemical characteristics in unit A and unit B are resulted from the different diagenetic durations of unit A and unit B.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.105-119
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• 2005

The surface sediments inside Songsanpo and Seogwipo Harbors, major harbors of Jeju Island, were collected three times (June, September and December, 2001) and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs) recommended by US-EPA as priority pollutants to assess their distribution levels and their biological effects on the marine organisms, and to suggest their possible origins. The concentrations of total PAHs inside Songsanpo and Seogwipo Harbors ranged from 41 to 288 ng/g on a dry weight basis with a mean value of 121 ng/g and from 14 to 268 ng/g with a mean value of 119 ng/g, respectively, and the levels were low as compared with those in other areas of the world. The sedimentary PAHs may be correlated with organic carbon and mud content to some extent. Based on comparisons of individual and total concentrations with effects-based sediment quality guidelines, the potential for the biological effects on the marine organisms were expected to be very low. From the examinations of the four PAH origin indices, such as LMW /HMW (low molecular weight 2-3 ring PAHs over high molecular weight 4-6 ring PAHs), phenanthrene/anthracene ratio, fluoranthene/pyrene ratio, chrysene/benzo[a]anthracene ratio, it can be concluded that the sediment PAH contaminations were ascribed to both of pyrolytic and petrogenic origins.

• Journal of Wetlands Research
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• v.6 no.1
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• pp.133-147
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• 2004

Environmental quality(water and sediment) was analyzed in the tidal flat of Saemangum of Jeonbuk Province, the west coast of Korea, using the 101 sediment samples and 69 water samples collected in September 4~13, 2001. Major water quality parameters with the means of 69 surface water samples are as follows; $25.51{\pm}0.68^{\circ}C$ for water temperature, $29.88{\pm}5.01$ for salinity, $1.40{\pm}0.78mg/L$ for COD, $0.352{\pm}0.417mg/L$ for DIN, and $0.027{\pm}0.023mg/L$ for phosphate, respectively. Higher values were found at the subestuary of Dongjin and Mangyung River, and lower values at the Saemangum embayment and Gomso Bay. There was a significant negative correlation between salinity and the other water quality parameters(p<0.0001) such as COD, nutrients, SS and N/P. This correlation suggested that the major pollution sources be from terrestrial inputs through tributaries in this area. Principal component analysis clearly revealed a spatial variation of water quality; stations with higher values of nutrients and COD located subestuary of tributaries. 14 sediment quality parameters including 8 trace metals were measured using the 101 surface sediment samples. Average values for the parameters are as follows; Al $2.28{\pm}0.92%$, Cd $0.61{\pm}0.27ppm$, Cu $8.95{\pm}4.06ppm$, Fe $1.19{\pm}0.37%$, Mn $182.31{\pm}77.45ppm$, Ni $10.83{\pm}4.97ppm$, Pb $15.20{\pm}4.35ppm$, Zn $41.34{\pm}34.62ppm$, COD $2.68{\pm}1.85mg/g\;dry$, AVS $0.04{\pm}0.08mg/g\;dry$, IL $1.29{\pm}1.08%$, water content $24.11{\pm}4.49%$, TN $0.02{\pm}0.02%$, TC $0.22{\pm}0.30%$. Spatial variations of sediment quality were not clear as water quality. Some higher values were found at the subestuary of Gum River and lower values at the other area. There was a significant positive correlation between the heavy metal concentrations and organic materials within the sediment(p<0.05). Enrichment factors showed the ranges of 1~2 for most of the metals in the sediment except zinc(1~6), indicating no serious exogenous input of heavy metals in the study area. Also, the heavy metal concentrations in the sediment were within the ranges found at the natural marine environments.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.4
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• pp.276-284
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• 2000

Distributions of organic carbon (Co$_{org}$), organic nitrogen (N$_{org}$), and heavy metals (Zn, Pb, Cr, Cu, Mn) were investigated in Lake Shihwa sediments. Surface and core samples were collected in April and September, 1997 and March, 1998 for the study. The results show that these components contents are variable with sampling timeand station. In surface sediments, both Co$_{org}$ and N$_{org}$ have similar distribution pattern in which their high contents found in stations located near the land, indicating that the streams and industrial wastes seem to act as point sources. The C$_{org}$ contents are linearly related with those of heavy metals. It appears, therefore, that the distribution of heavy metals may be partly controlled by a complex interplay of biogenic, terrestial, and anthropogenic factors. The C/N ratios from three stations are in the range of 3-32, with an average of 13.2. Vertical profiles of heavy metals in sediment cores are similar to those of C$_{org}$ and N$_{org}$. Copper content of sediments is enriched compared to that of reported value before dike construction, but Zn and Mn are not deposited considerably. Especially, Pb content show less variable. Currently, anthropogenic effects of industrial complex may not reached to drainage gate area where heavy metal contents are comparable with those adjacent to coastal sediments.

• Korean Journal of Environmental Biology
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• v.23 no.2 s.58
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• pp.163-172
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• 2005

Field survey on the marine environmental characteristics by the distribution of dinoflagellate cysts and organic matter carried out bimonthly at 14 stations in the central parts of South Sea, Korea from April 2002 to January 2003. The range of environmental factors on surface sediments such as water content, ignition loss (IL), chemical oxygen demand (CODs), particulate organic carbon (POC), particulate organic nitrogen (PON) and phaeopigment were $38.7\~68.9\%,\;3.9\~12.5\%,\;9.60\~44.05mgO_2\;gdry^{-1},\;3.12\~13.14mgC\; gdry^{-1},\;0.49\~2.01mgN\;gdry^{-1}\;and\;1.61\~29.51{\mu}g\;gdry^{-1}\;gdry-1$, respectively. A total dinoflagellate cysts identified were 33 species, which belonged to 18 genera,31 species, and 2 unidentified species. A cysts density were $42\~2,880\; cysts\;gdry^{-1}$. The dominant species of dinoflagellate cysts were Spinrferites bulloideus and Scrippsiella trochoidea all the year and autotrophic species was more abundant than heterotrophic species. The organic matter and dinoflgellate cysts were more abundant nearshore than offshore, and the origin of organic matter was autochthonous rather than from terrestrial. The two factors derived from the loading factor of PCA. Factor 1 was 'accumulation of oragnic matter in the offshore', factor 2 was 'cysts abundance', and the central parts of Korean South Sea was separated with 3 regions by score distribution of PCA.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.1
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• pp.1-13
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• 2006

A field survey on the spatio-temporal distribution characteristics and origins of organic matter in surface sediments was carried out monthly at six stations in Gamak Bay, South Korea from April 2000 to March 2002. The range of ignition loss(IL) was $4.6{\sim}11.6%(7.1{\pm}1.6%)$, while chemical oxygen demand(CODs) ranged from $12.25{\sim}99.26mgO_2/g-dry(30.98{\pm}19.09mgO_2/g-dry)$, acid volatile sulfide(AVS) went from no detection(ND)${\sim}10.29mgS/g-dry(1.02{\pm}0.58mgS/g-dry)$, and phaeopigment was $6.84{\sim}116.18{\mu}g/g-dry(23.72{\pm}21.16{\mu}g/g-dry)$. The ranges of particulate organic carbon(POC) and particulate organic nitrogen(PON) were $5.45{\sim}23.24 mgC/g-dty(10.34{\pm}4.40C\;mgC/g-dry)$ and $0.71{\sim}2.99mgN/g-dry(1.37{\pm}0.58mgN/g-dry)$, respectively. Water content was in the range of $43.1{\sim}77.6%(55.8{\pm}5.6%)$, and mud content(silt+clay) was higher than 95% at all stations. The spatial distribution of organic matter in surface sediments was greatly divided between the northwestern, central and eastern areas, southern entrance area from the distribution characteristic of their organic matters. The concentrations of almost all items were greater at the northwestern and southern entrance area than at the other areas in Gamak Bay. In particular, sedimentary pollution was very serious at the northwestern area, because the area had an excessive supply of organic matter due to aquaculture activity and the inflow of sewage from the land. These materials stayed longer because of the topographical characteristics of such as basin and the anoxic conditions in the bottom seawater environment caused by thermocline in the summer. The tendency of temporal change was most prominently in the period of high-water temperatures than low-water ones at the northwestern and southern entrance areas. On the other hand, the central and eastern areas did not show a regular trend for changing the concentrations of each item but mainly showed a higher tendency during the low-water temperatures. This was observed for all but AVS concentrations which were higher during the period of high-water temperature at all stations. Especially, the central and eastern areas showed a large temporal increase of AVS concentration during those periods of high-water temperature where the concentration of CODs was in excess of $20mgO_2/g-dry$. The results show that the organic matters in surface sediments in Gamak Bay actually originated from autochthonous organic matters with eight or less in average C/N ratio including the organic matters generated by the use of ocean, rather than terrigenous organic matters. However, the formation of autochthonous organic matter was mainly derived from detritus than living phytoplankton, indicated the results of the POC/phaeopigment ratio. In addition, the CODs/IL ratio results demonstrate that the detritus was the product of artificial activities such as dregs feeding and fecal pellets of farm organisms caused by aquaculture activities rather than the dynamic of natural ocean activities.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.46-51
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• 2000

Environmental quality regulations are used to establish the maximum permissible concentrations of heavy metals before a site can be deemed to be polluted or contaminated. This paper compares the results obtained by 0.IN HCl extraction and acid extraction method(HNO$_3$+HClO$_4$.HCl). The leaching efficiency of 0.1N HCl extraction is directly proportional to the final pH of leachate, due to the different solubilities of the heavy metals at different pH values, The severe differences between 0.1N HCl-extractable and total metal contents result mainly from the buffering effect of carbonates, present in sediment. samples. Application of sequential extraction experiments to some sediments collected from gully pot in Seoul illustrates a much stronger scavenging effect by Fe and Mn-hydroxides, carbonates and organic phases. As deduced from both sequential extraction and leaching experiments, the relative mobility of heavy metals is found to be: Mn>Zn>>Co>Cd>>Cu>Pb>Cr>Fe, in spite of large differences in heavy metal content and localization. Changes in the physicochemical environments (such as acidification) caused by a traffic accident may result in the severe environmental pollution of heavy metals of surrounding area( surface water and rivers).

• Journal of Environmental Science International
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• v.20 no.2
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• pp.163-174
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• 2011

Butyltin compounds in seawater, sediments and organisms inside Jeju Harbor of Jeju Island, Korea, were quantitatively determined to assess the extent of contamination and to evaluate the bioaccumulation in Thais clavigera (gastropod), Liolophura japonica and Cellana nigrolineata. In addition, imposex in T. clavigera was used to assess the sublethal effect of tributyltin compounds and its usage as a specific biomarker for these compounds was also studied. The main species in seawater was tributyltin (TBT) in March and June, monobutyltin (MBT) in August, but in sediments and organisms it was dibutyltin (DBT) and TBT, respectively, irrespective of survey time. TBT, the most toxic to aquatic organisms among BTs, was found at concentrations which were sufficient to have a serous effect on the sensitive organisms upon chronic exposure. The high correlations (r>0.7) between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints and their sources were negligible. The sedimentary organic matters have little influence on the distribution of BTs in marine environment and the lipid content in T. clavigera showed a significant correlation with TBT concentrations. Measurement of imposex T. clavigera was expected to be a very helpful tool for preliminary survey of BTs prior to trace analysis of those.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.1
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• pp.104-115
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• 2015

This study was conducted during April-June in 2008 and 2010, following the Taean Oil Spill. We measured year-to-year changes in benthos species abundances and composition in 16 intertidal zone regions of Chungcheongnam-do. In total, 154 species were found 2008 and 134 in 2010; the mean abundance per area was $403ind./m^2$ and $242ind./m^2$, respectively. In 2008, the 10 dominant species included four species of arthropods, three species of annelids, and three species of mollusks. In 2010, dominant species included five species of annelids, three species of mollusks, one species of arthropods, and one other species. We used bray-curtis similarity to group species and found two groups in 2008 and five in 2010, complementing our NMDS analysis. Finally, we tested correlations between abiotic and biotic factors, and implemented a BIO-ENV analysis, which showed that sediment type, MZ (Phi), and organic content are important environmental factors affecting benthos in the Chung-nam tidal flats.