• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.6
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• pp.699-709
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• 2017

We measured the grain size, total organic carbon (TOC), total nitrogen (TN), and heavy metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn) in order to understand the spatial distribution and pollution level of organic matter and metals in surface sediment around Goseong Bay, a shellfish farming area, Korea. The surface sediments were composed of finer sediments such as mud and clay. The concentration of TOC, TN, and heavy metals were much higher in the innermost bay than in the mouth and outside of bay. The spatial distribution of organic matter and heavy metals and C/N ratio (5-10) in sediment showed that the organic matter and heavy metals in sediment of the study region were significantly influenced by oceanic origin organic matter and anthropogenic sources, respectively. Based on the results of four assessment techniques (sediment quality guideline, geoaccumulation index, pollution load index, ecological risk index), the sediments around the Goseong Bay were a little polluted for heavy metals and the high metal concentrations in the northern region of bay could adverse impact on benthic organisms in sediment. Thus, the systematic management plan for the improvement of water and sediment environment and the concentrated monitoring of pollutants for sustainable aquaculture and seafood safety around Goseong Bay are necessary in the future.

• Journal of Environmental Science International
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• v.17 no.1
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• pp.29-36
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• 2008

A large amount of $2.1{\times}10^6m^3$ of polluted sediment was dredged from the Masan Bay and deposited in Gapo confined area, Masan, Korea. The six representative sediments were obtained and analyzed for issue components. The data was discussed with the species of benthos and their distribution. It was judged that toxicological effects of sediment analyzed ranged from ERL to ERM with copper and zinc, and ERL with cadmium, chrome, lead and nickel by the Adverse Biological Effects. The dredging index (DI) of sediments stabilized for 10 years since dumping the confined site was calculated and compared with the DI values of dredged sediment itself. DI values decreased from 0.67 to $0.07{\sim}0.18$, which reflects DI value less than 0.2 is good for benthos in the sediment by the natural recovery of dredged materials. The ecological recovery was confirmed in this confined area as a habitat of benthic organisms.

• Journal of Korean Society on Water Environment
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• v.35 no.2
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• pp.105-114
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• 2019

The objective of this study was to investigate the pollution assessment of organic matters, nutrients, and metals in sediment in major lakes (5 lakes and 17 sites) of Buk-han river using various sediment pollution assessment guidelines and indices. The concentrations of organic matters and nutrients were lower than class IV (Sediment pollution assessment guidelines of Korea) and Severe Effect Level (SEL, Sediment pollution assessment guidelines of Ontario). This results indicated that the lakes sediments were unpolluted and tolerable level for sediment dwelling organisms by organic matters and nutrients. However, several sites of Chuncheon and Soyang lakes were evaluated "heavily polluted" level by organic index (Org-index). The order of lakes by metals concentrations from the one with the highest concentration was Hwacheon, Chuncheon, Cheongpyeong, Uiam, Soyang. All lakes except Hwacheon were assessed unpolluted to marginally and tolerable level for sediment dwelling organisms by metals based on sediment pollution assessment guidelines (Korean and Ontario), indices of geoaccumulation ($I_{geo}$), pollution loading (PLI) and ecological risk (RI). In Lake Hwacheon, every investigated sites were polluted with metals, especially Hg, based on sediment pollution assessment guideline of Korea and indices ($I_{geo}$, PLI and RI). The dwelling organisms in sediment of Hwacheon Lake were likely to be severed by metals.

• Ocean and Polar Research
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• v.38 no.3
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• pp.171-184
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• 2016

In order to assess the level of contamination and identify the priority contaminants in the Busan coast, intensive sediment sampling was conducted and persistent organic pollutants and heavy metals were analyzed. The Sediment Quality Index (SQI) was derived based on the contaminant data by comparing with Sediment Quality Guidelines (SQGs) established in Korea, Canada, and Australia/New Zealand. Toxic contaminants were found to be widely distributed across the coast. Among organic contaminants, PAHs showed the highest concentration, followed by butyltins, nonylphenols, PBDEs, DDTs, PCBs, HCHs and CHLs. Heavy metals were also abundantly detected with the highest concentration of Zn followed by Cu > Cr > Pb > Ni > As > Cd > Hg. Compared to organic contaminants, most heavy metals, except for Cu and Hg, were homogeneously distributed along the coast in a good relationship with total organic carbon of sediment particles. In general, the concentrations of organic compounds and heavy metals were highest at the inner part of harbor areas with a tendency to decline from inside areas to the outside, indicating the high loading of pollutants from harbors. A high exceedance for low-SQGs and high-SQGs was found for TBT, p'-DDT, p,p'-DDD, Cu and Zn. The SQI scores calculated from low-SQGs and high-SQGs were in the range of 18-100 and 54-100, respectively. The inner part of Busan Harbor, Dadaepo Harbor, and Gamcheon Harbor were observed as being regions of concern. Overall, TBT, Cu, and p,p'-DDT were the chemicals most frequently exceeding SQGs and influencing SQI scores.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.4
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• pp.542-554
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• 2015

Grain size, the content of ignition loss (IL), and the concentrations of chemical oxygen demand (COD), acid volatile sulfide (AVS), and trace metals (Fe, Mn, Cu, Pb, Zn, Cd, Cr, As, and Hg) in surface sediments from the Taehwa River estuary, Ulsan, were measured to evaluate pollution levels and potential ecological risks of organic matter and trace metals in estuarine sediment. The mean grain size (Mz) of sediments in the study region ranged from $-0.8-7.7{\varphi}$ (mean $2.8{\pm}2.4{\varphi}$). Surface sediments in the upstream region of the Taehwa River were mainly composed of coarse sediments compared to the downstream region. The concentrations of IL, COD, AVS and trace metals in the sediment were much higher at downstream sites of Myeongchon Bridge in the vicinity of industrial complexes than at upstream sites of those in the vicinity of the residential areas due to the anthropogenic input of organic matter and trace metals by industrial activities. On the basis of several geochemical assessment techniques [sediment quality guidelines (SQGs), enrichment factor (EF), geoaccumulation index ($I_{geo}$), pollution load index (PLI) and ecological risk index (ERI)], the surfaces sediments in the study region are not highly polluted for trace metals, except for As. However, the higher concentrations in downstream study regions of the Taehwa River could impact benthic organisms including shellfish (i.e. Manila clam) in sediments.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.454-466
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• 2013

To evaluate the organic matter and trace metal pollution in intertidal sediment of the coastal zone, various geochemical parameters (grain size, ignition loss [IL], chemical oxygen demand [COD], acid volatile sulfide [AVS], and metals [Al, Fe, Cu, Pb, Zn, Cd, Cr, Mn, Hg, and As]) were measured for the intertidal surface sediment of the mainland and islands between Mokpo and Haenam in the southwestern coast of Korea. The surface sediments consist mainly of finer sediments, such as mud and silt. The concentrations of IL, COD, and trace metals in intertidal sediment were relatively high in the shoreline of the mainland than in that of islands and those in some stations exceeded the sediment quality guidelines (SQGs). Moreover, the concentrations of IL, COD, and trace metals (except As) in sediment showed relatively good positive correlations with mean grain size, indicating that the concentrations of organic matter and trace metals in intertidal sediment of the study region are dependent on grain size of sediment. Pollution evaluation for trace metals using geochemical assessment techniques, such as enrichment factor, geoaccumulation index, and SQGs, suggested that the intertidal sediments in the study region show light pollution with Cr and moderate pollution with As. More extensive interdisciplinary studies are required to determine the potential causes of As pollution in intertidal sediment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.626-637
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• 2013

We measured the grain size, ignition loss (IL), chemical oxygen demand (COD), acid volatile sulfide (AVS) and trace metals (Al, Fe, Cu, Pb, Zn, Cd, Cr, Mn, Hg, and As) of intertidal surface sediment collected from 11 islands (62 stations) in the southern region of Jeollanam Province. The objective of this research was to evaluate the organic matter and trace metals contaminations of sediments from coastal island tidal flats. Surface sediment texture was characterized as follows: mud, sandy silt, muddy sand, and slightly gravelly sand facies. The finer sediments are mainly dominated in the northern part of each island. The concentrations of IL, COD, AVS and some trace metals (Al, Fe, Zn, Cr, Cu, and Hg) were higher in the northwestern part of Wan Island and the area between Gogeum and Sinji Islands, and were associated with relatively finer sediment, as compared to other locations. The concentrations of Mn, Pb, Cd, and As were higher in the northwestern and southeastern parts of Geoguem and Pyungil Islands, but were not correlated with mean grain size. Based on sediment quality guidelines (SQGs), the concentrations of trace metals were lower than the values of effect range low (ERL), used in United States, and threshold effects level (TEL), used in Korea, with exception of As. Similarly, the intertidal sediments were moderately contaminated with As, based on the the enrichment factor (EF) and the geoaccumulation index ($I_{geo}$). The high concentration of As in intertidal sediments from this study region may be due to the input of naturally or artificially contaminated submarine groundwater, contaminated waste from seaweed aquaculture operations and/or land-based seaweed processing facilities. Further studies are needed to identify the sources of As in this study region, and to determine the effects of As contamination on coastal ecosystem.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.759-771
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• 2011

We evaluated the pollution levels of organic matter and metallic element (Fe, Cu, Pb, Zn, Cd, Ni, Cr, Mn, As, and Hg) in the intertidal surface sediments of Aphae Island using several sediment quality guidelines (SQGs) and assessment techniques for sediment pollution. Based on the textural composition of sediment, the surface sediments were classified into two main sedimentary facies: slightly gravelly mud and silt. The concentrations of chemical oxygen demand (COD) and acid volatile sulfide (AVS) in the sediments ranged from 4.6-9.9 (mean $7.4{\pm}1.1$) $mgO_2/g{\cdot}dry$ and from ND-0.53 (mean $0.04{\pm}0.10$) mgS/$g{\cdot}dry$, respectively. These values were considerably lower than those reported from a farming area in a semi-enclosed bay of Korea and for SQGs in Japan. The metallic element concentrations in the sediments varied widely with the mean grain size and organic matter content, implying that the concentrations of metallic elements are influenced mainly by secondary factors, such as bioturbation, the resuspension of sediment, and anthropogenic input. The overall results for the comparison with SQGs, enrichment factor (EF), and geoaccumulation index ($I_{geo}$) indicate that the surface sediments are slightly polluted by Cr and Ni, and moderately polluted by As. Our results suggest that the intertidal surface sediments of Aphae Island are not polluted by organic matter or metallic elements and the benthic conditions are suitable for healthy organisms.

• Ocean and Polar Research
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• v.45 no.3
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• pp.103-111
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• 2023

To evaluate the impact of effluents from land-based fish farms on the coastal ocean of Wando, Korea, we analyzed inorganic nutrients, particulate organic carbon (POC), dissolved organic carbon (DOC), and colored dissolved organic matter (CDOM) in the effluent and influent of land-based fish farms during the summer (July) of 2021. The average concentrations of nutrients (Dissolved inorganic nitrogen, phosphorus, and silicate; DIN, DIP, and DSi, respectively) in the effluents of this study area were 17±3.7 μM, 1.4±0.7 μM, and 14±1.6 μM, respectively. The average concentrations of POC and DOC were 37±22 μM and 81±13 μM, respectively, with POC accounting for about 30% for total organic carbon in effluents. The Reduced Dissolved Inorganic Nitrogen/Total Dissolved Inorganic Nitrogen ratio (0.7), potential short-period index, indicates that the discharge of nutrients excreted by the fish and unconsumed feed into coastal water results in such nutrients being deposited and accumulated in the sediment. Subsequently, this continuous accumulation triggers the release of ammonium ions during organic matter decomposition, and the ammonium-enriched waters that encroach on fish farms as influent seem to be due to the diffusion of high concentrations of ammonium from bottom sediment. Furthermore, we used fluorescence indices to examine the characteristics of organic matter sources, obtaining mean values of 1.54±0.19, 1.06±0.06, and 1.56±0.06 for the humification index, biological index, and fluorescence index, respectively, in the effluent. These results indicate that the organic matters had an autochthonous origin that resulted from microbial decomposition, and such organic matters were rapidly generated and removed by biological activity, likely supplied from the sediment. Our results suggest that the effluent from land-based fish farms could be a potential source of deoxygenation occurrence in coastal areas.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.5
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• pp.511-518
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• 2019

Evaluating the habitat suitability of potential aquaculture sites for cultured species is critical to the sustainable use of tidal flats. This study evaluated the habitat suitability index (HSI) of 12 sites in a tidal flat aquaculture farm at Geunso Bay, Taean, in June 2016. The parameters used to model the suitability index were Growth (water temperature, chlorophyll ${\alpha}$, hydrodynamics), Survival (sediment-sand, mean size, air exposure), and Environment (DO, salinity). The HSI was calculated using weighted and No weighted geometric means. The results showed high habitat suitability at the bay's entrance (HIS; No weighted, 0.60-0.70; weighted, 0.60). Hydrodynamics, air exposure, sediment-sand and mean size are thought to have a significant impact on habitat selection by Manila clams Ruditapes philippinarum. This study explored the optimum habitat for Manila clams by calculating the HSI, providing basic data for tidal flat management.