• Korean Journal of Environment and Ecology
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• v.28 no.4
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• pp.442-449
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• 2014

This study was carried out to measure the seasonal changes in community structure and species composition of marobenthos on the subtidal area of Saemangeum regions. The macrobenthos comprised 64 species were during this study, predominately annelids (53.0%), arthropods (18.8%), mollusks (18.8%) and 9.4% were from other species. Total abundance was 24,885 individuals, comprising 19,805 individuals of annelids (79.6%), 4,620 individuals of mollusks (18.5%), 295 individuals of other species (1.2%), and 165 individuals of arthropods (0.7%). After analyzing the bray-curtis similarity, had two large groups (A, B) the inside and outside of Saemangeum dike. They all matched the nMDS analysis. I evaluated the benthic community health using BPI (Benthic pollution Index). There are no significant differences between the station position and the inside or outside of Saemangeum dike. But, highest BPI level was in March.

• Ocean and Polar Research
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• v.35 no.2
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• pp.69-83
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• 2013

Metal concentrations in creek water, sewer outlets and core sediments were analyzed to identify the potential origin of metal pollution and to evaluate the extent of metal pollution and potential toxicity of Lake Shihwa. Mean concentrations for dissolved metals in creek water and sewer outlets were 1.6~136 times higher than those in the surface seawater of Lake Shihwa. Metal concentrations in creek water from an industrial region were also higher than those from municipal and agricultural regions, indicating that the potential source of metal pollution in the study area might be mainly due to industrial activities. The vertical profiles of metals in core sediments showed an increasing trend toward the upper sediments. Extremely higher concentrations of metals were observed in the vicinity of Banweol industrial complex. The results of a geo-accumulation index indicated that Cu, Zn and Cd were highly polluted. By comparing the sediment quality guidelines such as TEL and PEL, six metals such as Cr, Ni, Cu, Zn, Cd and Pb levels in core sediments nearby industrial complex exceeded the PEL value. Mean PEL quotient (mPELQ) was used to integrate the estimate of potential toxicity for measured metals in the present study. Mean PELQs in core sediments from Lake Shihwa ranged from 0.2~2.3, indicating that benthic organisms nearby the industrial complex may have been adversely affected.

• Korean Journal of Ecology and Environment
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• v.52 no.4
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• pp.385-393
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• 2019

Chironomid communities are indicators of water pollution because of their ability to thrive under freshwater conditions. However, it is difficult to distinguish between chironomid larvae based on morphology. DNA barcoding, based on nucleotide sequences of marker genes, can be used to identify chironomid larvae. Samples of chironomid larvae were collected from Gwangju Stream and Pungyeongjeong Stream, tributaries of the Yeongsan River in South Korea. We identified 3 subfamilies, 13 genera, 16 species, and 1 cryptic species. There were 7 genera and 10 species from the subfamily Chironominae, 5 genera and 5 species from subfamily Orthocladiinae, 1 genus and 1 species from subfamily Tanipodinae, and the cryptic chironomid species of the family Chironomidae. There were 21 individuals from, 7 species and 1 cryptic species from the Gwangju Stream and 24 individuals, belonging to 10 species from the Pungyeongjeong Stream. The only species detected in both streams was Cricotopus bicinctus. The relationship between water quality and the species detected was difficult to explain, but the number of species showed a tendency to increase at sites where water quality was poor. Additional investigations and studies are needed to understand the relationship between water quality and the chironomid species occurring in these two streams.

• Korean Journal of Environmental Biology
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• v.34 no.2
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• pp.79-90
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• 2016

This study investigates seasonal variation and spatial distribution of meiobenthic community of Gamak Bay (one of the major bays of southern coastal area of Korea). Total of 6 surveys of 10 stations took place, once in February, June and October of 2009 and through 2010. Community structure, taxon diversity (H') and nematodes/copepods ratio of meiobenthos were studied in Gamak Bay. During the study period, nematodes and harpacticoids were the most dominant taxa among the meiofaunal groups in Gamak Bay. Taxon diversity (H') was the highest at the outer stations and the lowest at the inner stations in the Gamak Bay. The nematodes/copepods ratio was seasonally studied as an index of pollution monitoring for the benthic ecosystem at each station. As a result, nematodes/copepods ratio was the highest at the inner stations and the lowest at the outer stations in Gamak Bay.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.4
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• pp.510-520
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• 2021

To understand the status of organic matter and heavy metal pollution in surface sediment of a fish farming area, we have measured the concentrations of total organic carbon (TOC), total nitrogen (TN), and heavy metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn) in surface sediments of a fish farming area near Tongyoung-Geoje coast. The mean concentrations of TOC and TN were 22.7 mg/g and 3.4 mg/g, respectively, and were much higher than those in surface sediments of a semi-enclosed bay in the southern coast of Korea. The mean concentrations of As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn were 10.5 mg/kg, 0.37 mg/kg, 82.9 mg/kg, 127 mg/kg, 4.19%, 0.041 mg/kg, 596 mg/kg, 39.5 mg/kg, and 175 mg/kg, respectively, and the mean concentrations of Cd and Cu were three times higher than those in surface sediments of shellfish farming area in the southeastern coast of Korea. In addition, the concentrations of TOC and corrected Cu exceeded the values of sediment quality guidelines applied in Korea, and pollution load index (PLI) and ecological risk index (ERI) showed that the metal concentrations in the sediments of some fish farming area have a strongly negative ecological impact on benthic organisms, although most metal concentrations did not exceed the sediment quality guidelines. Based on overall assessment results, the surface sediments of fish farming areas in the study region are polluted with organic matter and some heavy metals. Thus, a comprehensive management plan is necessary to improve the sedimentary environments, identify primary contamination sources, and reduce the input of pollution load for organic matter and heavy metals in the sediments of fish farming areas.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.4
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• pp.380-391
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• 2003

Surface sediments were collected from Gwangyang and Yeosu Bays to evaluate their sedimentological characteristics and geochemical aspects of both the benthic environment and heavy metal pollution. The grain size distribution includes both sandy and muddy sediments. Sand-rich sediments occur mainly near the POSCO and the channel between Namhedo and Yeosu Bando, while elsewhere mud-dominated sediments are present. TOC content ranges from 0.2 to 2.1 % and C/N ratios indicate that the range arises from the mix of organic matter. The C/S ratios of this organic matter show that parts of the study area are anoxic or have sub-anoxic bottom conditions. The hydrogen sulfide content of the sediment has a range of 0.7 to 301 ppm, with a high content occurring inshore of Myodo Island, where it indicates a polluted environment. The enrichment factor (Ef) and index of accumulation rate (Igeo) of ten heavy metals (Co, Ni, Cu, Cd, Pb, Li, Zn, V, Cr, Ba) show that parts of the study area contain from one to seven times more Pb and Ba, and from 0.8 to 3.5 times more of the other elements than the mean sediment value. The Igeo values of V and Cd show that different parts of the area can be classified as heavily polluted, heavily to moderately polluted, or more or less unpolluted. Those areas that have both high levels of enrichment and high accumulation rates of heavy metals contain predominantly fine sediments with a high organic matter and hydrogen sulfide content.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.666-677
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• 2019

In order to understand the distribution of organic matter and heavy metal concentrations in the surface sediments of fishery resources protection areas (FRPAs), we measured the grain size, ignition loss (IL), chemical oxygen demand (COD), acid volatile sulfide (AVS), and concentrations of heavy metals (As, Cd, Cr, Cu, Fe, Hg, Pb, and Zn) in the surface sediments collected at 54 stations of 5 FRPAs (Gamak Bay, Yeoja Bay, Deukryang Bay, Wando coast, and Youngkwang coast) in the southwestern coast of Korea in February 2017. The surface sediments consisted of fine sediment such as mud, with 2.9~8.8Ø (7.4±0.1Ø) of mean grain size. The average concentrations of IL, COD, and AVS in the sediments were 4.63±0.96 %, 13.0±3.1 mgO₂/g·dry, and 0.092±0.124 mgS/g·dry, respectively, and were lower for sediments from the Youngkwang coast than those from other FRPAs. The average concentrations of heavy metals in the sediment were 7.5±0.9 mg/kg for As, 0.04±0.02 mg/kg for Cd, 70.2±9.7 mg/kg for Cr, 15.3±2.8 mg/kg for Cu, 3.3±0.5 % for Fe, 0.014±0.003 mg/kg for Hg, 25.0±6.0 mg/kg for Pb, and 99±14 mg/kg for Zn, respectively, and were relatively higher for sediments in the inner bays than those from the outer bays and coasts. Based on the assessment of sediment samples using the sediment quality guidelines (SQGs), the pollutant load index (PLI), and the ecological risk index (ERI), the surface sediments of FRPAs in the southwestern coast of Korea do not appear to be polluted by heavy metals, suggesting that the heavy metal concentrations in the sediments would not adversely impact aquatic and benthic organisms.

• The Korean Journal of Malacology
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• v.32 no.3
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• pp.149-155
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• 2016

To assess the effects of environmental factors on the sustainability of cultured ark shell Scapharca broughtonii production, we investigated the habitat characteristics of shellfish-farming bays (Gangjin Bay, Yeoja Bay, Keoje Bay and Deukryang Bay). We measured the physiochemical parameters (temperature, salinity, dissolved oxygen, nutrients, chemical oxygen demand and Chlorophyll a) and the geochemical characteristics (chemical oxygen demand, ignition loss, C/N ratio and C/S ratio). Surface sediments were collected from several shellfish-farming bays to examine the geochemical characteristics of both the benthic environment and heavy metal pollution. The grain sizes for Gangjin Bay, Yeoja Bay and Keoje Bay were similar, at the ratio of silt and clay in comparison with Deukryang bay of it. The C/N ratio was more than 5.9, reflecting the range arising from the mix of marine organisms and organic matter. The C/S ratio (more than 4.2) showed that the survey area had anoxic or sub-anoxic bottom conditions. The index of accumulation rate (Igeo) of the metals showed that those research areas can be classified as heavily polluted, heavily to moderately polluted, or more or less unpolluted, respectively. We suggested that the growth of ark shell Scapharca broughtonii in the shellfish-farming bay was effected by the various environmental conditions.

• Ecology and Resilient Infrastructure
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• v.8 no.2
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• pp.112-119
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• 2021

In 2012, the National Park Service conducted an ecological health assessment to efficiently preserve and manage the ecosystem. The need for improving pre-existing management indicators was recognized from the revised Natural Park Act because, while the indicators of the existing evaluation system focused on endangered species, ecosystem disturbance, diversity, water quality (BOD, DO), and habitat fragmentation, they did not reflect the lack of indicators for marine ecological assessment, policy changes, and the time demands. The evaluation results comprised a five-point grading system, which made the analysis of immediate changes, difficult. Therefore, the benthic pollution index (BPI) and habitat restoration indicators were added to improve the evaluation system. The National Park was assessed using 10 classifications, however, only four classifications were evaluated. The ratings were divided into five states, and ten classes were presented as pictograms. The assessment results showed a similar trend as the indicators were improved, increasing from level 3 to level 5. However, the results of the Wolaksan National Park after improvement in the indicators were lower than that before the improvement, whereas, for the Juwangsan National Park, it was higher. This study aims at contributing to the scientific and systematic management of the national park ecosystem by improving the ecological health assessment system.

• Journal of Environmental Impact Assessment
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• v.29 no.1
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• pp.8-25
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• 2020

Industrialization has increased the production of road-deposited sediments (RDS) and the level of heavy metals in those RDS, which can have a significant impact on the surrounding aquatic environments through non-point pollution. Although the relationship between contamination characteristics and particle size of RDS is important for pollution control, there is very little information on this. In this study, we investigated the characteristics of grain size distribution and heavy metal concentrations in the road-deposited sediments (RDS) collected from 25 stations in Shihwa Industrial Complex. The environmental impact of RDS with particle size is also studied. I_geo, the contamination assessment index of each metal concentration, represents the RDS from Shihwa Industrial Complex are very highly polluted with Cu, Zn, Pb and Sb, and the levels of those metals were 633~3605, 130~1483, 120~1997, 5.5~50 mg/kg, respectively. The concentrations of heavy metals in RDS increased with the decrease in particle size. The particle size fraction below 250 ㎛ was very dominant with mass and contamination loads, 78.6 and 70.4%, respectively. Particles less than 125 ㎛ of RDS were highly contaminated and toxic to benthic organisms in rivers. RDS particles larger than 250 ㎛ and smaller than 250 ㎛ were contaminated by the surrounding industrial facility and vehicle activities, respectively. As a result of this study, the clean-up of fine particles of RDS, smaller than 125-250 ㎛, is very important for the control and reduction of non-point pollution to nearby water in Shihwa Industrial Complex.