• The Korean Journal of Pesticide Science
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• v.13 no.1
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• pp.1-12
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• 2009

To assess the effect of butachlor on freshwater aquatic organisms, acute toxicity studies for algae, invertebrate and fishes were conducted. The algae grow inhibition studies were carried out to determine the growth inhibition effects of butachlor (Tech. 93.4%) in Pseudokirchneriella subcapitata (formerly knows as Selenastrum capriconutum), Desmodesmus subspicatus (formerly known as Scendusmus subspicatus), and Chlorella vulgaris during the exposure period of 72 hours. The toxicological responses of P. subcapitata, D. subspicatus, and C. vulgaris to butachlor, expressed in individual $ErC_{50}$ values were 0.002, 0.019, and $10.4mgL^{-1}$, respectively and NOEC values were 0.0008, 0.0016, and $5.34mg\;L^{-1}$, respectively. P. subcapitata was more sensitive than any other algae species. Butachlor has very high toxicity to the algae, such as P. subcapitata and D. subspicatu. In the acute immobilisation test for Daphnia magna, the 24 and $48h-EC_{50}$ values were 2.55 and $1.50mg\;L^{-1}$, respectively. As the results of the acute toxicity test on Cyprinus carpio, Oryzias latipes and Misgurnus anguillicaudatus, the $96h-LC_{50}s$ were 0.62, 0.41 and $0.24mg\;L^{-1}$, respectively. The following ecological risk assessment of butachlor was performed on the basis of the toxicological data of algae, invertebrate and fish and exposure concentrations in rice paddy, drain and river. When a butachlor formulation is applied in rice paddy field according to label recommendation, the measured concentration of butachlor in paddy water was $0.41mg\;L^{-1}$ and the predicted environmental concentration (PEC) of butachlor in drain water was $0.03 mg\;L^{-1}$. Residues of butachlor detected in major rivers between 1997 and 1998 were ranged from $0.0004mg\;L^{-1}$ to $0.0029mg\;L^{-1}$. Toxicity exposure ratios (TERs) of algae in rice paddy, drain and river were 0.004, 0.05 and 0.36, respectively and indicated that butachlor has a risk to algae in rice paddy, drain and river. On the other hand, TERs of invertebrate in rice paddy, drain and river were 3.6, 50 and 357, respectively, well above 2, indicating no risk to invertebrate. TERs of fish in rice paddy, drain and river were 0.58, 8 and 57, respectively. The TERs for fish indicated that butachlor poses a risk to fish in rice paddy but has no risk to fish in agricultural drain and river. In conclusion, butachlor has a minimal risk to algae in agricultural drain and river exposed from rice drainage but has no risk to invertebrate and fish.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.1
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• pp.1-8
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• 2015

We investigated the effect of monochromatic light emitting diode (LED) on the growth of diatoms Nitzschia sp., Phaeodactylum tricornutum, Skeletonema sp. and green algae Chlorella vulgaris. The four microalgae species were cultured under blue LED (450 nm), yellow LED (590 nm), red LED (650 nm) and fluorescent lamp (mixed wavelengths). The maximum growth rates and cell densities of Nitzschia sp., P. tricornutum and Skeletonema sp. were highest under blue LED, followed by fluorescent lamp, red LED and then yellow LED, however those of C. vulgaris were highest under red LED. This result indicates that blue LED is favorable for the growth of diatoms. Thus, the growth of microalgae under monochromatic light might be species-specific or taxon-specific. Also, these results could be used as an important information in future for remediation of heavy metal contamination in the sediments using LED and microalgae.

• Ocean and Polar Research
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• v.37 no.3
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• pp.201-209
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• 2015

To examine the effects of increased $CO_2$ concentration and seawater temperature on the photosynthesis and growth of forest forming Ecklonia cava (Laminariales, Phaeophyta), sporophytic discs and gametophytes were cultured under three $pCO_2$ concentrations (380, 750, 1000 ppm), four temperatures (5, 10, 15, $20^{\circ}C$ for sporophytes; 10, 15, 20, $25^{\circ}C$ for gametophytes), and two irradiance levels (40, $80{\mu}mol$ photons $m^{-2}s^{-1}$) for 5 days. Photosynthetic parameter values ($ETR_{max}$, $E_k$, and ${\alpha}$) were generally higher as sporophytic discs were grown under low temperature and increased $CO_2$ concentration at 750 ppm. However, photosynthesis of Ecklonia sporophytes was severely inhibited under a combination of high temperature ($20^{\circ}C$) and 1000 ppm $CO_2$ concentration at the two photon irradiance levels. The growth of gametophytes was maximal at the combination of 380 ppm (present seawater $CO_2$ concentration) and $25^{\circ}C$. Minimal growth of gametophytes occurred at enriched $pCO_2$ concentration levels (750, 1000 ppm) and high temperature of $25^{\circ}C$. The present results imply that climate change which is increasing seawater temperature and $pCO_2$ concentration might diminish Ecklonia cava kelp beds because of a reduction in recruitments caused by the growth inhibition of gametophytes at high $pCO_2$ concentration. In addition, the effects of increased temperature and $pCO_2$ concentration were different between generations - revealing an enhancement in the photosynthesis of sporophytes and a reduction in the growth of gametophytes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.827-834
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• 2013

The effects of environmental factors, such as irradiance, daylength, salinity, and desiccation, on the growth of Lithophyllum yessoense and Hildenbrandia rubra sporelings were examined. Sporelings of each species were cultured with 10, 50, 80, 120, $150{\mu}mol$ photon $m^{-2}s^{-1}$ for 14 days and their maximum growth occurred under $80{\mu}mol$ photon $m^{-2}s^{-1}$. Germlings of both species survived for 21 days in darkness, and even the L.yessoense germlings grew. In the salinity experiment, sporelings of each species survived for 7 days and died after 14 days under 20 and 25 psu, but the sporelings grew well under 34 psu. Physiological features of each species with respect to the evaluated daylengths (8, 12, 14 and 16 h) were slightly different, and maximal growth occurred at 16 h for L. yessoense and at 14 h for H. rubra sporelings. Mortality of the sporelings increased with the exposure period, but H. rubra was less tolerant to desiccation than L. yessoense. In conclusion, sporelings of the two species showed similar growth responses to various environmental factors with slightly different physiological features with respect to salinity, daylength, and desiccation. However, more ecological and physiological studies on slow-growing crustose algae are required to elucidate the expansion of barren ground around the coastal areas of Korea.

• Journal of Environmental Impact Assessment
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• v.10 no.2
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• pp.109-121
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• 2001

Water environment and freshwater algae were studied in the upstream of the Tamjin River Dam. Among the environmental factors, DO concentration in the Tamjin River ranged from 9.0 mg $O_2/l$ to 9.2 mg $O_2/l$, pH from 7.0 to 7.1 and conductivity from $98{\mu}S/cm$ to $100{\mu}S/cm$. Average concentration of $NH_4$ and $NO_3$ ranged from $40{\mu}g\;N/l$ to $56{\mu}g\;N/l$ and from $489{\mu}g\;N/l$ to $611{\mu}g\;N/l$, respectively. $NO_3$ was more plentiful above 9~15 fold than that of $NH_4$. Average concentrations of soluble reactive phosphorus and soluble reactive silicon were $2{\mu}g\;P/l$ and 1.6 mg Si/l, respectively. Particulaly, Si nutrient increased by heavy rain events during summer season. The ratios of N/P and Si/P ranged from 248 to 261 and from 640 to 740, respectively. It is assumed that P would be limiting nutrient on the freshwater algal growth. Average content of planktonic chlorophyll-a ranged from $5{\mu}g/l$ to $13{\mu}g/l$. Mean contents of chlorophyll-a, phaeo-pigment and ash-free dry matter of periphyton were $50.3mg/m^2$, $11.9mg/m^2$, $11.5g/m^2$ in the main stream and $30.1mg/m^2$, $5.6mg/m^2$, $7.8g/m^2$ in the tributary. By comparison of the epilithon biomass, the main stream was higher with 1.5~2.1 fold than the tributary. The impotant algae were composed of diatom Achnanthes linearis, A. minutissima, Fragilaria crotonensis, Gomphonema gracile, Tabellaria flocculosa and blue-green algae Microcystis aeruginosa. In the relative abundance of the phytoplankton and epilithon, the serial dominance were diatom > green algae > blue-green algae, and diatoms were very abundant in comparison with other algal phylum.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.70-75
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• 1986

The population and kinds of algae causing the waterbloom on the rice seedling bed and the damage of young rice plant by the nuisance green phytoplanktonic algae in rice field were studied to find out the efficiency of fertilizers and the effect of methods of fertilizers application in the rice field, laboratory, pot and green house. pot and green house. The results obtained were summarized as follows; 1. In the rice seedling bed, the kinds of algae causing waterblooms were identified mainly photosynthetic bluegreen algae as the Anabaena, Ulothrix and Oscillatoria spp. in reclaimed saline soil. Micromonospora, Oscillatoria, and Chlamydomonas spp. were habitated mainly in plain. Whereas, Spyrogyra, Oscillatoria and Navicula spp. were identified mainly in mauntainous area. 2. In the rice field, the nuisance phytoplanktonic green algae were identified mainly Scenedesmus, Chlamidospora, and Micromonospora spp. in Gimjae plain, in Namweon mountainous area and Gangjin costal plain, respectively. 3. The algal biomass has been havily habitated in which rice field were constituted with high pH value and high concentration of $NH^+_4-N$ and $NO^-_3-N$ in surface water and in soil with the optimum temperature for the algal growth ($22-30^{\circ}C$). 4. In the laboratory experiment, maximum algal biomass were obtained at levels of 80 ppm for the nitrogen and 20 ppm for the phosphorus. And were obtained of the levels of 40 ppm in the case of joint application of N and $P_2O_5$. 5. From the pot experiment, compare of the control plot, an addition of nitrogen alone or nitrogen+phosphorus enhanced algal biomass while the phosphorus alone did not. 6. Surface application of fertilizer was remarkably increased of algal biomass than did the whole layer or deep layer application.

• Journal of Environmental Impact Assessment
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• v.24 no.3
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• pp.278-286
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• 2015

Pilot scale system was designed to identify the growth and movement of algae, depending on environmental changes(retention time, nutrient concentration, etc) in Gangjeong-Goryeong Weir of the Nakdong River. Considering the stability of algal culture and easy observation of algal growth, pilot scale system was made of transparent acrylic material(3 sets of flexible cylindrical water tanks with 1 m diameter and 4 m height). Auxiliary equipments include light intercepter, water inflow device for different water depth and storage of reclaimed water. The retention time was 2 days(before construction of weir; treatment 1), 8 days(after construction of weir, 2013; treatment 2) and 30 days(2014; treatment 3). According to the water temperature of treatment 1 were similar by depth, treatment 3 showed a difference between the surface(0 m) and bottom(4 m) more than $3^{\circ}C$. DO, pH showed relatively high in the surface than the bottom. Nutrients showed eutrophic condition in all experiments. The Chlrophyll-a concentration of the treatment 1 showed a relatively lower value than the Chlrophyll-a concentration of the treatment 2 and 3. Therefore, the retention time was considered to influence the growth of phytoplankton.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.2.1-2.7
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• 2013

Objectives Tricalcium phosphate and calcium hydrogenorthophosphate are high production volume chemicals, mainly used as foodstuff additives, pharmaceuticals, lubricants, synthetic resin, and disinfectants. Phosphate has the potential to cause increased algal growth leading to eutrophication in the aquatic environment. However, there is no adequate information available on risk assessment or acute and chronic toxicity. The aim of this research is to evaluate the toxic potential of phosphate compounds in the aquatic environment. Methods An aquatic toxicity test of phosphate was conducted, and its physico-chemical properties were obtained from a database recommended in the Organization for Economic Cooperation and Development (OECD) guidance manual. An ecotoxicity test using fish, Daphnia, and algae was conducted by the good laboratory practice facility according to the OECD TG guidelines for testing of chemicals, to secure reliable data. Results The results of the ecotoxicity tests of tricalcium phosphate and calcium hydrogenorthophosphate are as follows: In an acute toxicity test with Oryzias latipes, 96 hr 50% lethal concentration ($LC_{50}$) was >100 (measured:>2.14) mg/L and >100 (measured: >13.5) mg/L, respectively. In the Daphnia test, 48 hr 50% effective concentration ($EC_{50}$) was >100 (measured: >5.35) mg/L and >100 (measured: >2.9) mg/L, respectively. In a growth inhibition test with Pseudokirchneriella subcapitata, 72 hr $EC_{50}$ was >100 (measured: >1.56) mg/L and >100 (measured: >4.4) mg/L, respectively. Conclusions Based on the results of the ecotoxicity test of phosphate using fish, Daphnia, and algae, $L(E)C_{50}$ was above 100 mg/L (nominal), indicating no toxicity. In general, the total phosphorus concentration including phosphate in rivers and lakes reaches levels of several ppm, suggesting that phosphate has no toxic effects. However, excessive inflow of phosphate into aquatic ecosystems has the potential to cause eutrophication due to algal growth.

• Clean Technology
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• v.23 no.1
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• pp.27-33
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• 2017

In this study, toxicities of seven metals (Cu, Cd, Cr, As(III), As(V), Zn, Ni) and five metal oxide nanoparticles (NPs: CuO, ZnO, NiO, $TiO_2$, $Fe_2O_3$) were evaluated based on the growth of Chlorella vulgaris. Effect on algae growth was evaluated by integrating the results of absorption, chlorophyll content, and cell count. The toxicity rankings of metals was observed as Cr ($0.7mgL^{-1}$) > Cu ($1.7mgL^{-1}$) > Cd ($3.2mgL^{-1}$) > Zn ($3.9mgL^{-1}$) > Ni ($13.2mgL^{-1}$) > As(III) ($17.8mgL^{-1}$) ${\gg}$ As(V) (> $1000mgL^{-1}$). Slightly different orders and sensitivities of metal toxicity were examined depending on endpoints of algal growth. In case of NPs, regardless of endpoints, similar toxicity rankings of NPs ($TEC_{50}$) were observed, showing ZnO ($2.4mgL^{-1}$) > NiO ($21.1mgL^{-1}$) > CuO ($36.6mgL^{-1}$) > $TiO_2$ ($62.5mgL^{-1}$) > $Fe_2O_3$ ($82.7mgL^{-1}$). These results indicate that an integrating results of endpoints might be an effective strategy for the assessment of contaminants.

• ALGAE
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• v.30 no.1
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• pp.59-66
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• 2015

The growth and hole formation of Ulva australis were examined at seven coastal areas of Korea between July and August, 2013. Animal species and weight growing on the Ulva fronds were estimated at Haseom, Pohang, and Woedo. The effects of wave exposure on the morphological features and residential animals of Ulva fronds were investigated at wave-exposed and sheltered sites of Seongsan on October 19, 2013. U. australis had different frond areas ($82-665cm^2$), hole areas ($2.5-6.3cm^2$), and hole numbers (9.8-41.3 holes) at the seven sites. Within $0.1m^2$ of Ulva frond, hole areas ranged from 0.37 to $5.94cm^2$, and between 4.9 and 36.2 holes were observed. Fourteen residential animal species were observed at the three evaluated sites, 75.0 (Haseom) to 408.7 individuals $100g^{-1}$ Ulva (Pohang) per site. The dominant residential species at each site differed with Amphithoe sp. at Haseom, Monodonta spp. at Pohang, and Pagurus sp. at Woedo. The growth (frond area, wet weight) and hole number of Ulva fronds, and the number of residential animals were significantly greater in samples collected from the sheltered shore than the wave-exposed shore of Seongsan. The present results showed U. australis grew well at sheltered shores and had more holes on the fronds due to abundance of residential animals. The dominant residential animals (crabs, gammaridea, and snails) were similar in the Ulva populations of sheltered and wave-exposed shores, but greater species diversity was observed at the exposed shore (18 species ver. 11 species). In conclusion, U. australis is a keystone species providing habitat to various invertebrates and frond holes are positively correlated to the number of residential animals.