• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.3
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• pp.303-309
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• 2013

Marine algal flora and community structure were investigated seasonally at three sites in Gijang on the south-east coast of Korea from February 2006 to January 2007. A Total of 74 species were collected and identified, including 8 green algae, 16 brown algae, and 50 red algae. Of these, 15 species were found throughout the survey period. Mean biomass was 823.2-1,615.4 g wet weight $m^{-2}$ in winter, 689.1-3,196.8 g wet weight $m^{-2}$ in spring, 574.5-1,219.9 g wet weight $m^{-2}$ in summer, and 747.6-1,616.2 g wet weight $m^{-2}$ in autumn. The flora could be classified into six functional groups: coarsely branched form (37.8%), thick leather form (18.9%), sheet form (13.5%), filamentous form (12.2%), jointed calcareous form (10.8%) and crustose form (6.8%). The R/P, C/P and (R+C)/P values reflecting the flora characteristics were 3.13, 0.50 and 3.63, respectively. The number of marine algae species and the biomass in Gijang area were markedly reduced when compared with previous studies. This result suggests possible future changes in the algal vegetation, considering the physical and chemical pollution loadings in the coastal marine environment of this area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.5
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• pp.535-541
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• 2018

This study evaluated the sanitary state of seawater and shellfish in Yongnam-Gwangdo area from January 2014 to December 2016. The sampling stations for sanitary survey in Yongnam-Gwangdo area were composed of 41 seawater stations and 5 oyster Crassostrea gigas stations. The samples were collected monthly at each station. Shellfish-borne disease is associated with bacteria and viruses in the presence of fecal coliforms. Bacteriological pollution levels of shellfish increase with seawater quality. Therefore, fecal coliforms are very important criteria for evaluating the safety of fisheries in coastal areas. The geometric mean and the estimated 90th percentile ranges of total and fecal coliforms for seawater were 1.8-11.7, 2.8-233.6, <1.8-6.7 and 1.8-100.2 MPN/100 mL, respectively. The range of E. coli levels for oysters was <20-1,300 MPN/100 g. Based on various standards, the sanitary condition in Yongnam-Gwangdo area was evaluated as follows: clean area (Korean criteria), conditionally approved area (US criteria) and class B (EU criteria).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.772-784
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• 2011

We measured grain size, organic matter, and metallic elements (Fe, Cu, Pb, Zn, Cd, Cr, Mn, Hg, and As) in intertidal sediments collected from six islands in the western part of Jellanam Province in order to evaluate heavy metal contamination in the tidal flat sediments of coastal islands. The evaluation of metal contamination was carried out using geochemical assessment techniques such as sediment quality guidelines (SQGs), enrichment factor (EF), and geoaccumulation index ($I_{geo}$). Surface sediments were classified into four sedimentary facies: sand, gravelly muddy sand, slightly gravelly mud, and silt. The concentrations of heavy metals in intertidal sediments from Jaeun, Amtae, Biguem, and Docho islands showed good positive correlations with mean grain size and ignition loss, indicating that the concentrations of metallic elements in these sediments were dependent on grain size and the organic matter content. The concentrations of heavy metals in sediments from almost all of the stations were lower than two criterion values proposed by the National Oceanic and Atmospheric Administration (NOAA) in the United States. Based on the EF and $I_{geo}$ results, surface sediments were a little polluted for Cr and were moderately polluted for As. Our results suggest that more intensive studies are necessary in the future in order to determine the major source of As in intertidal sediment and to evaluate the As pollution level in macrobenthos.

• Advances in environmental research
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• v.1 no.1
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• pp.15-35
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• 2012

Mercury (Hg) is a global environmental pollutant that has been the cause of many public concerns. One particular concern about Hg in aquatic systems is its trophic transfer and biomagnification in food chains. For example, the Hg concentration increases with the increase of food chain level. Fish at the top of food chain can accumulate high concentrations of Hg (especially the toxic form, methylmercury, MeHg), which is then transferred to humans through seafood consumption. Various biological and physiochemical conditions can significantly affect the bioaccumulation of Hg-including both its inorganic (Hg(II)) and organic (MeHg) forms-in fish. There have been numerous measurements of Hg concentrations in marine and freshwater fish worldwide. Many of these studies have attempted to identify the processes leading to variations of Hg concentrations in fish species from different habitats. The development of a biokinetic model over the past decade has helped improve our understanding of the mechanisms underlying the bioaccumulation processes of Hg in aquatic animals. In this review, I will discuss how the biokinetic modeling approach can be used to reveal the interesting biodynamics of Hg in fish, such as the trophic transfer and exposure route of Hg(II) and MeHg, as well as growth enrichment (the increases in Hg concentration with fish size) and biomass dilution (the decreases in Hg concentration with increasing phytoplankton biomass). I will also discuss the relevance of studying the subcellular fates of Hg to predict the Hg bioaccessibility and detoxification in fish. Future challenges will be to understand the inter- and intra-species differences in Hg accumulation and the management/mitigation of Hg pollution in both marine and freshwater fish based on our knowledge of Hg biodynamics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.561-567
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• 2021

The edible sargasso seaweed hijiki Sargassum fusiforme is known to have high concentration of arsenic, which is a threat to human health, particularly due to inorganic arsenic. In this study, various methods were used to remove inorganic arsenic from steamed hijiki concentrate. The highest concentration of arsenate [As(V)] in both raw and processed hijiki during steamed hijiki manufacturing process was within the range of 8.213-14.356 mg/kg, and it is a potential source of inorganic arsenic, which can result in re-contamination and cause environmental pollution. The removal efficiencies of the various removal methods were within the range of 57.3-83.4%, and 19.0% reduction was achieved using activated carbon and alginate bead. Further, activated carbon showed the best adsorption effect of inorganic arsenic. Therefore, we suggest that activated carbon is a suitable efficient method for removing inorganic arsenic and has low operational costs in field applicability.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.615-625
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• 2023

This study evaluated the bacteriological safety of seawater and abalone produced in Uisin-myeon, Jindo-gun from September 2020 to December 2022 and calculated the effect of inland pollution sources on seawater and abalone. We surveyed 33 stations for seawater, 4 stations for abalone, and 7 stations for discharge water of major inland pollutants. We analyzed the coliform group, fecal coliform and Escherichia coli (E. coli) as bacteria indicators. In 924 seawater samples, the geometric mean of the coliform group and fecal coliform were <1.8-5.6 MPN/100 mL and <1.8-2.7 MPN/100 mL, respectively. The estimated 90^th percentile range for the coliform group and fecal coliform were <1.8-42 MPN/100 mL and <1.8-8.4 MPN/100 mL, respectively. The fecal coliform and E. coli levels for 107 abalone were <18-460 MPN/100 g and <18-78 MPN/100 g respectively. Moreover, the analyzed standard plate count was <30-7,700 CFU/g. The fecal coliform level and diffusion area in 7 inland pollutants were <1.8-3,300,000 MPN/100 mL and 2-2,500 m, respectively. The bacteriological safety of seawater and abalone in Uisin-myeon, Jindo-gun, was demonstrated to be a designated area according to Korean standards, a conditionally approved area per US standards, and Class A according to EU standards.

• Journal of Environmental Impact Assessment
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• v.17 no.1
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• pp.1-9
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• 2008

Non-point pollution is caused by many diffusive sources, unlike a point pollution derived from industrial wastewater treatment plants or sewage treatment plants. Runoff of non-point pollutants is originated from rainfall or thawing in short period of time moving over and through the a ground surface. They cause ill effect on the quality of neighboring aquatic environment. To prevent effectively the wash off from non-point pollutant, it should be immediately reduced at the source or be treated after gathering of runoff water. This study has been carried out for the best width of riparian buffer zone. So we implemented the experiment in terms of its depth, width and kind of vegetations and calculated the reduction of pollutants loading. The experimental zone encompasses the watershed of Namhan River (Kyunggido Yangpyunggun Byungsanri). The region was divided into 5 land cover sectors : grass, reed, pussy willow, mixed(grass+pussy willow) and natural zone to compare effectiveness of vegetation. Water samples from four points have been collected in different depths. And the pollutant removal efficiency by sectors with different plant species was yielded through influent with one of each sample. And we obtained the correlation between the width of riparian buffer zone and the removal efficiency of pollutants. Using correlation result, the width of riparian buffer zones which needs to improve the water quality of river could be derived.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.3
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• pp.43-50
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• 2004

This study looked into the water quality improvement effect of reed (Phragmites communis), bur reed (Sparaganium stoloniferum), Alisma canaliculatum, and Hydrocharis dubia in order to develop native hydrophytes suitable to natural-type wetlands for ecological restoration. The result confirms that the concentration of wastewater was lowered in most plants indicating a possibility in wastewater treatment. Among four species, reed (Phragmites communis) and bur reed (Sparaganium stoloniferum) were most effective in removing a majority of contaminants. Considering that reed (Phragmites communis) is a species that has been used most often among hydrophytes, bur reed (Sparaganium stoloniferum), which is a native species in Korea, showed equivalent level of outstanding effect. In the physiological and growing activity and its relations to water quality improvement effect, each species appeared differently. Reed (Phragmites communis) and bur reed (Sparaganium stoloniferum) were best also in physiological and growing activity. In the case of Hydrocharis dubia, growth was strong in polluted water environment but its physiological activity was poor, indicating that it was under stress. The growth and physiological activity of Alisma canaliculatum were also poor, indicating that it too is being stressed. However, measuring organic contents in the plants of each species shows that the organic contents of Alisma canaliculatum was high. Alisma canaliculatum is a species effective in removing pollutants in water, although it is under stress. A unique phenomenon in removing water pollution with plants is that each species removed different pollutants. In the case of Alisma canaliculatum, which was relatively poor in removing pollution, it was remarkable in reducing nitrogen and phosphorus. Hydrocharis dubia was also effective in eliminating floating matter.

• Journal of Korean Society on Water Environment
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• v.32 no.6
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• pp.562-569
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• 2016

Recently, Low Impact Development (LID) is being used in Korea to control urban runoff and nonpoint source pollution. In this study, we evaluated the reduction of surface runoff from a study area, as the effect of connecting three bioretention as LID-BMP. Surface runoff and storage volume of bioretention is estimated by the Curve Number (CN) method. In this study, the storage volume of bioretention is divided by the volume of surface runoff and precipitation which directly enters the bioretention. The ratio of captured surface runoff volume to storage volume is highly influenced by the ratio of drainage area to surface area of bioretention. The high bioretention surface area-to-drainage area ratio captures more surface runoff. The ratio of 1.2 captures 51~54% of the total surface runoff, ranging from 5-30cm of bioretention depth; a ratio of 6.2 captures 81~85%. Three connected bioretentions could therefore captures much more runoff volume, ranging from $35.8{\sim}167.3m^3$, as compared to three disconnected bioretentions at their maximum amount of precipitation with non-effluent from the connecting three bioretentions. Hence, connecting LID-BMPs could improve the removal efficiencies of surface runoff volume and nonpoint source pollution.

• The Korean Journal of Malacology
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• v.20 no.1
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• pp.93-105
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• 2004

Arkshell clams, Scapharca broughtonii, are economically important edible bivalves and widely cultivated in the Southern coast of Korea. Recently, the production of S. broughtonii has been dramatically decreased and various reasons including chemical pollution were suspected to be related to the production declines. However, it remains unknown whether the chemical pollution levels of the surrounding environments were high enough for the biological and ecological disturbance for the population of S. broughtonii, because no systematic toxicological study using S. broughtonii has been conducted previously. In the present study, we exposed arkshell clams, S. broughtonii to various waterborne pollutants including heavy metals (Cd, Cu and Hg), ammonia and organotins (tributyltin and triphenyltin) to determine the effect concentrations of these pollutants for the survival of S. broughtonii for 20 days. The median lethal concentrations ($LC_50$) of S. broughtonii were 2.1 mg/l for Cd, 0.065 mg/l for Cu, 0.40 mg/l for Hg, 79.4 mg/l for total ammonia (1.9 mg/l for unionized ammonia), 0.5 ${\mu}$g/l for TBT, and 14${\mu}$g/l for TPhT. Lethal toxicity of the most pollutants increased with both exposure duration and concentration. The toxicity of TBT was greatest for S. broughtonii, followed by TPhT > Cu > Hg > Cd > ammonia. The sensitivities of S. broughtonii to heavy metals and TBT were comparable to those of other aquatic organisms, but they were relatively tolerable to ammonia. The environmental concentrations of the tested pollutants were compared with the effect concentrations of those for the survival of S. broughtonii to assess the potential risks of the pollutants in the field conditions.