• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.1
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• pp.79-91
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• 2005

Wetland systems are widely accepted natural water purification systems around the world in nonpoint sources pollution control. Constructed wetlands have become a popular technology for treating contaminated surface and wastewater. In this study, the field experiment to reduce nonpoint source pollution loadings from polluted stream waters using wetland system was performed from June 2002 to March 2004, including winter performance using four newly constructed wetlands. The Dangjin stream water flowing into Seokmun estuarine lake was pumped into wetlands, and inflow and hydraulic residence time of the system was $500m^{3}{\~}1500m^{3}/day\;and\;2{\~}5$ days respectively. After 3 years operation plant-coverage was about $80~90\%$ from zero at initial stage even with no plantation. Average water quality of the influent in growing season was BOD_{5}\;3.96mg/L$, TSS 22.98 mg/L, T-N 3.29 mg/L, T-P 0.30 mg/L. The average removal rate of four wetlands for $BOD_{5},\;TSS,\;T-N\;and\;T-P$ in growing season was $24\%$, $62\%$, $54\%$, and $51\%$, respectively. And average water quality of the influent in winter season was $BOD_{5}$ 4.92 mg/L, TSS 12.47 mg/L, T-N 5.54 mg/L, and T-P 0.32 mg/L, respectively. The average removal rate of four wetlands for them was $-21\%$. $23\%$, $33\%$, and $53\%$, respectively. The reason of higher BOD_{5} effluent concentration in winter season might be that low temperature restrained microorganism activity and a organic body from the withered plant and algae was flown out. Except the result of $BOD_{5}$, the effectiveness of water quality improvement in winter season was satisfactory for treating polluted stream waters, and $BOD_{5}$ variation was within the range of background concentration. Performance of the experimental system was compared with existing data base (NADB), and it was within the range of general system performance. Overall, the wetland system was found to be satisfactory for NPS control such as improvement of polluted stream water.

• Journal of Wetlands Research
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• v.15 no.3
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• pp.289-300
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• 2013

In this study, two types of wetland plants, Eichhornia crassipes (a floating plant) and Ceratophyllum demersum (a submerged plant) were introduced to wetland mesocosms to understand how the water properties of wetlands such as pH, dissolved oxygen content, water temperature, oxidation reduction potential, and nutrient concentrations are affected by different types of wetland plant. The floating plant lives on the water surface and can block light penetration; it exhibited the lowest water temperature and temperature difference between lower and upper layers. After the addition of contaminants, the dissolved oxygen (DO) concentration decreased abruptly but recovered continuously in all mesocosms; especially the submerged plants, which photosynthesize in water, showed the largest increases in DO and diel periodicity DO, as well as in pH value. The oxidation-reduction potential in both water and sediment were affected by the presence of wetland plants and plant type and the results suggest that various aspects of wetland biogeochemistry are affected by the presence and type of wetland plants. The total nitrogen and phosphorous concentrations in water decreased in the following order: Water only < Water + Soil < Floating Plants < Submerged Plants. Although both floating and submerged plants can control algal concentrations, the effect was more prominent for floating plants.

• Journal of fish pathology
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• v.26 no.3
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• pp.265-274
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• 2013

The growth, reproduction, gametophyte(G)/tetrasporophyte(T) ratio, and diseases of Chondrus ocellatus populations were examined at 3 sites (Samcheok, Youngduk, Pohang) of East coast and at 2 sites (Hakampo, Manripo) of West coast in between July and August, 2013. Average plant lengths were 6.10~9.69 cm and it was minimum at Manripo and maximum at Pohang population. In general, average plant length and weight of C. ocellatus were greater on East coast than West coast populations. The proportion of vegetative plant was between 26.7~66.7 %, and G/T ratio of total plants including vegetative plants after testing resorcinol method was 3:2 on the East coast where is gametophyte dominant area. However, G/T ratio was 1:1 at Hakampo and 1:2.3 at Manripo representing tetrasporophyte dominance. In the present study, Korean C. ocellatus have various diseases (white colour and green colour), an endophytic alga(Ulvella sp.), and many epiphytic macroalgae and diatoms. Healthy C. ocellatus plants were about 20~40 % in summer population and most of plants had disease. Chondrus ocellatus had a filamentous green alga, endophytic Ulvella sp. which was not identified. The endophyte is easily observed in C. crispus growing in Europe and Canada and it is recognised as a pathogen destroying population and reducing yield of C. crispus. Thus more interest and research on the endophytic algae and disease of C. ocellatus are required.

• Korean Journal of Organic Agriculture
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• v.26 no.3
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• pp.393-408
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• 2018

This study was carried out to investigate how chlorella dry powder added to the feed of laying hens influences on the egg quality and the composition of egg yolk's fatty acid. Moisture content, ash content, crude protein content, and crude fat content were 12.8%, 10.8%, 18.0% and 2.5%, respectively. The moisture content of the chlorella powder added to the feed was about 1.54%, the ash content was 6.53%, the crude protein content was 54.56%, and the crude fat content was 2.45 %. After feeding chlorella, compared to the control, the color of egg shell significantly became darker. The hardness of egg shell was increased for 10 days after chlorella feeding and was significantly strengthened. Thickness of egg shell was significantly thicker. The height of egg whites was increased. After 10 days of providing chlorella, the quality of egg white was 92.0 HU (Haugh Unit), which was significantly higher than 84.8 HU, the quality of the control. The color of egg yolk significantly revealed more yellow than that of the control. Egg weight was increased by 7.5% after 15 days of feeding chlorella. Protein content was increased by 11.9% and 10.7% after 10 and 15 days of feeding, respectively. The major compositions of fatty acid content of egg yolk fed with chlorella diet were oleic acid, trans-linoleic acid, palmitic acid, ${\alpha}$-linolenic acid, stearic acid, DHA, EPA, palmitoleic acid, and heptadecanoic acid, respectively. Palmitoleic acid was decreased in the eggs fed with chlorella diet compared to the control. The Saturated Fatty Acid (SFA) content of the control was higher than that of the eggs fed with chlorella. The content of Unsaturated Fatty Acid (UFA) was higher in egg yolks fed with chlorella than in the control. The ratio of UFA to Saturated Fatty Acid (SFA) was higher in egg yolks fed with chlorella than in the control. These results suggest that the addition of chlorella to the feed of the laying hens brings positive effects on the improvement of egg quality and lowering of the Unsaturated Fatty Acid of egg yolk.

• Journal of Marine Life Science
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• v.9 no.1
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• pp.9-21
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• 2024

Paralytic shellfish poisoning (PSP) including Saxitoxin (STX) is caused by harmful algae, and poisoning occurs when the contaminated seafood is consumed. The mouse bioassay (MBA), a standard test method for detecting PSP, is being sanctioned in many countries due to its low detection limit and the animal concerns. An alternative to the MBA is the Neuro-2a cell-based assay. This study aimed to establish various test conditions for Neuro-2a assay, including cell density, culture conditions, and STX treatment conditions, to suit the domestic laboratory environment. As a result, the initial cell density was set to 40,000 cells/well and the incubation time to 24 hours. Additionally, the concentration of Ouabain and Veratridine (O/V) was set to 500/50 μM, at which most cells died. In this study, we identified eight concentrations of STX, ranging from 368 to 47,056 fg/μl, which produced an S-shaped dose-response curve when treated with O/V. Through inter-laboratory variability comparison of the Neuro-2a assay, we established five Quality Control Criteria to verify the appropriateness of the experiments and six Data Criteria (Top and Bottom OD, EC₅₀, EC₂₀, Hill slop, and R² of graph) to determine the reliability of the experimental data. The Neuro-2a assay conducted under the established conditions showed an EC₅₀ value of approximately 1,800~3,500 fg/μl. The intra- & inter-lab variability comparison results showed that the coefficients of variation (CVs) for the Quality Control and Data values ranged from 1.98% to 29.15%, confirming the reproducibility of the experiments. This study presented Quality Control Criteria and Data Criteria to assess the appropriateness of the experiments and confirmed the excellent repeatability and reproducibility of the Neuro-2a assay. To apply the Neuro-2a assay as an alternative method for detecting PSP in domestic seafood, it is essential to establish a toxin extraction method from seafood and toxin quantification methods, and perform correlation analysis with MBA and instrumental analysis methods.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.1
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• pp.24-28
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• 1981

As one of the fundamental studies for the breeding of marine algae, this paper deals wit_the effects of plant hormone on the growth of microscopic filamentous gametophyte of Undaria pinnatifida. The results obtained are summarized as follows: (1) All zoospores were settled on slide glass, germinated and developed into gametophytes, without the growth of germination tubes when treated with 0.1 mg/l of 2.4-D, or 0.1, 1.0, or 5.0 mg/1 of Keinetin. (2) The best growth effect in total average was observed at 0.1 mg/1 of Keinetin, when the growth-rate was $248.9\%$ in contrast with control, and was followed by 1.0 mg/1 of IAA ($243.3\%$), and 0.05 mg/1 of 2.4-D ($205.6\%$). (3) It was certain that the growth-effect by each plant hormone had some differences between male and female gametophytes. IAA was very effective in the growth of male gameto-phytes but Keinetin in that of females. Especially in females, the efficiency of Keinetin was recorded best at $239.0\%$ at 5.0 mg/l and $222.0\%$ at 0.1 mg/1. On the other hand, it was $195.1\%$ in its best at 0.5 mg/1 of IAA, and $146.6\%$ was recorded best in 2.4-D at 0.05 mg/1.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.79-85
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• 1981

As one of the fundamental studies for the breeding of marine algae, the effects of several plant hormones (IAA, Gibberellin, 2.4-D, NAA, Kinetin) on the growth of Porphyra-fronds, P. tenera Kjell. form tamatsuensis Miura, were investigated from January 21 to February 21 1981. The fronds used for the experiment were dissected out at $25mm^2$ size, and cultured in modified Provasoli's ESP medium supplemented with various concentrations of each plant growth regulators. The culture was kept under constant water temperature of $5^{\circ}C$ in 14 hrs. photoperiod and illuminated with 2,400 lux by fluorescent light. Based on the results of first experiment, the culture of fronds for the secondary experiment was carried out at $5^{\circ}C\;and\;10^{\circ}C$ in medium containing various levels of Kinetin from April 6 to 24, and compared the growth of two groups at each concentrations with each other, The results obtained are summarized as follows : (1) The best growth efficiencies were observed at 5.0mg/1 of each plant hormones except Gibberellin. Among them, the highest growth-rate was $312.5\%\;(345.3\%\;in\;frond\;size)$ in contrast with control at 5.0mg/1 of Kinetin, and was followed by $257.5\%\;(236.1\%)$ in 2.4-D,$166.7\%(147.6\%)$ in IAA and $141.7\%\;(167.7\%)$ in NAA, but that in Gibberellin was $247.9\%(241.9\%)$ at 10.0mg/l. (2) Especially, the fronds cultured at 5.0mg/1 of Kinetin were deep black-brown in colour, and had vivid, healthy chloroplasts in their all cells. On the contrary, the fronds cultured in other media were discoloured to light black-brown or green-drown, and almost all cells were vacuolated or shrunk gradually into death.(3) There was an obvious difference between the best growth-rates of the fronds cultured at 5.0mg/l of Kinetin at $5^{\circ}C$ and those at $10^{\circ}C$. The former was $366.7\%$, the latter $318.8\%$ but the difference was little at lower concentrations. (4) Many abnormal cells grown up to $25.0-27.5\mu$ in diameter were found among the marginal cells of fronds which showed the best growth in Kinetin, and the fronds wire $41.0-42.0\mu$ in thickness which was thicker by $10.0\mu$ or so than the others. (5) In two fronds at 1.0mg/1 of Kinetin cell-divisions were observed, which might developed into antheridium, but it was doubtful whether due to the efficiency of Kinetin.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.5
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• pp.253-261
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• 2015

In this study, Chlorophyll-a (chl-a) prediction model and multiple parameters affecting algae occurrence in Mulgeum site were evaluated by statistical analysis using water quality, hydraulic and climate data at Mulgeum site (1998~2008). Before the analysis, control chart method and effect period of typhoon were adopted for improving reliability of the data. After data preprocessing step two methods were used in this study. In method 1, chl-a prediction model was developed using preprocessed data. Another model was developed by Method 2 using significant parameters affecting chl-a after data preprocessing step. As a result of correlation analysis, water temperature, pH, DO, BOD, COD, T-N, $NO_3-N$, $PO_4-P$, flow rate, flow velocity and water depth were revealed as significant multiple parameters affecting chl-a concentration. Chl-a prediction model from Method 1 and 2 showed high $R^2$ value with 0.799 and 0.790 respectively. Validation for each prediction model was conducted with the data from 2009 to 2010. Training period and validation period of Method 1 showed 20.912 and 24.423 respectively. And Method 2 showed 21.422 and 26.277 in each period. Especially BOD, DO and $PO_4-P$ played important role in both model. So it is considered that analysis of algae occurrence at Mulgeum site need to focus on BOD, DO and $PO_4-P$.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.87-97
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• 2023

In this study, we examined the effects of a large wildfire in the coastal area of Uljin-gun. The analysis of water quality and the dominant species, species composition, and community structure of marine algal was conducted quarterly in 2022 at Nagok (F-1), Hujeong (F-2), Bongpyeong (F-3), and Gongse Port (F-C) in Uljin-gun. As a result of water quality analysis, the pH, a factor of wildfire impact was 8.07~8.30 and 8.12~8.48 in surface and bottom layers, respectively, which are normal values in coastal waters of the East Sea, suggesting no direct impact from wildfires. By marine algal species composition, the coastal areas show the following order: Rhodophyta (58.1%) > Ochrophyta (25.8%) > Chlorophyta (14.5%) > Magnoliophyta (1.6%). By season, Undaria pinnatifida was the most dominant at Nagok and Hujeong in March and June, which in September and November, Gelidium elegans and Lithophyllum sp. were the most dominant in Bongpyeong and Gongse Port, respectively. In the cluster analysis, the stations were divided into two groups according to presence and absence of specific marine algal by season. The dominant species were U. pinnatifida, G. elegans and D. divaricata in group A, and Lithophyllum sp. was mainly present in group B. Thus, the species composition and group structure reflected the normal seasonal change pattern with water temperature variation and showed little significant difference from the control site, suggesting no direct effects of the wildfire on algae distribution in Uljin.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.273-281
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• 2004

A feeding trial was conducted with Euglena strains grown under different media. The effect of supplementation of Euglena on the performance, nutrient availability and fatty acid composition of breast muscle was studied. In experiment I, two hundred ten hatched broiler chicks (Ross) were assigned to seven dietary treatments for 5 weeks. Each treatment consisted of 3 replications with 10 birds each. Control diet was formulated to have $22\%$ CP and 3,150 kcal ME/kg for starter diet, $19\%$ CP and 3,200 kcal ME/kg for finisher diet. Euglena gracilis Z. (EG) was added to control diet at the plevel of 0.25, 0.5, $1.0\%$ and Euglena gracilis Z. bleached and DHA enriched (EGBD; a strain mutated by streptomycin and cultivated in DHA enriched medium) at the level of 0.5, 1.0, $2.0\%$ in the diet. In experiment 2, two hundred fifty hatched broiler chicks (Ross) were assigned to five dietary treatments: T1; Control, T2; T1 + Euglena gracilis Z. DHA enriched (EGD; cultivated in DHA enriched medium) $0.5\%$, T3; T1 + EGD $1.0\%$, T4; T1 + EGBD $0.5\%$, T5; T1 + EGBD $1.0\%$. The weight gain and feed consumption were measured weekly. Fatty acid composition of breast muscle was determined. In experiments I and 2, Euglena supplementation had no significant effects on weight gain, feed intake and feed conversion ratio. In experiment 1, EGBD treatments significantly increased DHA concentration but decreased concentration of linoleic acid and arachidonic acid in breast muscle. EGBD 2% treatment showed the highest DHA concentration (14.27%) which is 3.9 times of that of the control ($3.66\%$). In experiment 2, $1.0\%$ EGBD treatment showed highest EPA, lignoceric acid and DHA level in breast muscle (P<0.05). Also, EGD treatments significantly increased DHA and EPA concentration. It was concluded that EGBD and EGD can be supplemented to broiler diet to produce DHA enriched broiler meat.