• Journal of Korean Society on Water Environment
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• v.31 no.1
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• pp.49-54
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• 2015

Acute toxicity test with Daphnia magna has a variety of factors such as incubation condition of test species, food quality and proficiency of laboratory workers. Therefore, proper proficiency testing samples were required for evaluating the competence of laboratory workers. This study aims to propose some appropriate proficiency testing samples for laboratory workers of acute toxicity test with Daphnia magna. Proposed four kinds of standard samples (Sample A, B, C, and D) for proficiency testing were selected from reference materials which were recommended from Canada and USA WET(Whole Effluent Toxicity) authorities. Proposed standard samples were tested by trial application of proficiency testing, homogeneity and stability checks using repeatability test. Sample A, C and D were estimated ad the suitable candidates for proficiency test standard samples except for Sample B. In addition, Sample A was proved to be the most suitable sample.

• Journal of Ecology and Environment
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• v.31 no.2
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• pp.125-129
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• 2008

To predict Daphnia secondary productivity along a trophic gradient indexed as total phosphorus (TP) concentration, we estimated energy transfer efficiencies from food quality for Daphnia such as eicosa-pentaenoic acid (EPA) or docosahexaenoic acid (DHA) content. Eleven flow-through Daphnia magna growth experiments were conducted with seston from 9 lakes, ponds and river waters. Primary productivities were estimated from food supply rates in the flow-through experiments, producing energy transfer efficiencies from seston to D. magna. We found DHA content was the best predictor of energy transfer efficiencies among the essential fatty acids. An asymptotic saturation model explained 79.6% of the variability In energy transfer efficiencies. Based on empirical data in this study and empirical models from literature, we predict that Daphnia productivity would peak in mesotrophic systems by decreasing food quality and Increasing food quantity along trophic gradient.

• Journal of environmental and Sanitary engineering
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• v.10 no.2
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• pp.46-58
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• 1995

Acute toxicity of heavy metals( Mercury, Cadmium, Lead, Chromium and Copper ), Organophosphorus insecticides( EPN, 2, 4- D, and Parathion ), and other chemicals( Arsenic, Cyanide, and Phenol) to Daphnia magna, and Vibrio fischeri was analysed. Daphnia magna to most toxic chemicals was most sensitive among test organisms alld then Daphnia magna seems to be more useful in toxic test of water. Daphnia magna was more sensitive to heavy metals than insecticides and other chemicals. The sensitivity of Visrio JircAeri to heavy metals was not so different from that to insecticides and the sensitivity to other chemicals was low. Visrio JircAeri appears to be more sensitive to toxic chemicals than Photobacterium phosphoreum, which was compared as recorded values of P.phosphoreum. Toxic chemicals were classified as Group 1 which had a high $EC_{50}$ or $LC_{50}$ value and the low increase rate of toxicity according to the increase of concentration, Group 2 which had a high $EC_{50}$ or $LC_{50}$ value and the high increase rate of toxicity, Group 3 which had a low $EC_{50}$ or $LC_{50}$ value and the high increase rate of toxicity, and Group 4 which had a low $EC_{50}$ or $LC_{50}$ value and the low increase rate of toxicity. To Daphnia magna, Lead, Chromium EPN, and Parathion were included in Group 1 : Mercury and Copper in Group 2 : Arsonic and Cadmium in Group 3 : Cyanide, 2, 4-B, and Phenol in Group 4. To Visrio JircAeri, Lead, Chromiurl 2, 4- D, and Parathion were included in Group 1 : Merecury, Cadmium and Arsenic in Group 2 : Cyanide in Group 3 : EPN, Copper, and Phenol in Group 4.

• Korean Journal of Environmental Biology
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• v.34 no.2
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• pp.91-96
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• 2016

This study presents the potentiality of harmful algal bloom (HAB) control through the zooplankton, Daphnia magna. In case of co-cultivated D. magna with cyanobacteriums (Microcystis aeruginosa, Anabaena variabilis, and Limnothrix planctonica), the D. magna showed the $80.2{\pm}4.2%$, $39.7{\pm}4.0%$, and $25.9{\pm}10.9%$ of control efficiency for M. aeruginosa, A. variabilis and L. planctonica, respectively. Furthermore, algal control was investigated by using supernatant including metabolite/secretion of D. magna. The algal control efficiencies of supernatant were recorded as $24.9{\pm}9.9%$ and $8.9{\pm}4.0%$ for M. aeruginosa and A. variabilis, respectively. From the results of present study, it may be possible to provide a feasible way for development of eco-friendly HAB control methods.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.1000-1007
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• 2010

In this study, toxicity monitoring of sediments collected from 25 stations in the Geum river basin was conducted using Daphnia magna and Moina macrocopa. According to the results of acute toxicity tests (immobilization and mortality) of organic extracts of semdiments, Miho stream showed much less toxicity than Gap and Nonsan streams. In particular, significant toxicity was observed in both species for St.15 and St.16 sediment samples that passed through Deajeon city as a branch of Gap stream. For Nonsan stream, St.23 sediment showed high toxicity toward M. macrocopa. This site seemed to be affected by upper agricultural industrial complex. Additionally, M. macrocopa showed a higher sensitivity than D. magna for organic extracts of sediments. In the case of toxicity tests using sediment pore water and aqueous extracts, only pore water of St.27 sediment was toxic against D. magna. Toxicity identification evaluation showed that hydrogen sulfide was likely a major toxicant in the pore water.

• Korean Journal of Environmental Biology
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• v.33 no.4
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• pp.468-475
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• 2015

Nonylphenol is one of endocrine disruptors, as structurally stable, hydrophobic compounds exhibit high condensability and long-lasting in the natural environment. The purpose of this study was to determine the toxic effects of nonylphenol on Daphnia magna. In acute toxicity test, D. magna was exposed for 48 h at concentrations of 0, 10, 18, 32, 56 and $100{\mu}g\;L^{-1}$ nonylphenol. In chronic toxicity test, D. magna were exposed through water for 21 days at concentrations of 0, 1.0, 1.8, 3.2, 5.6 and $10{\mu}g\;L^{-1}$ nonylphenol. Acute toxicity was assessed on the basis of immobility, while chronic toxicity was assessed on the basis of fecundity. The acute toxicity test on nonylphenol was showed that the values of 24 h and 48 h $EC_{50}$ were $25.0{\mu}g\;L^{-1}$ and $13.7{\mu}g\;L^{-1}$, respectively. In chronic test, fecundity was reduced significantly at $5.6{\mu}g\;L^{-1}$ of nonylphenol. These results indicated that nonylphenol have some hazard for acute or chronic toxicity to freshwater invertebrate organism.

• Environmental Analysis Health and Toxicology
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• v.25 no.2
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• pp.153-159
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• 2010

Perfluorooctane sulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA) are the principal chemicals known as perfluoroalkyl acids (PFAs). Despite the widespread use of these compounds, relatively little is known about their fate and effects. The purpose of this study was to determine the toxic effects of PFOS and PFOA on Daphnia magna. In the acute toxicity test, D. magna were exposed for 48 hours at concentrations of 0, 30, 45, 67.5, 101.25 and 151.88 mg/L PFOS, and 0, 100, 160, 225, 337.5 and 506.25 mg/L PFOA, respectively. In the case of chronic toxicity test, D. magna were exposed through water for 21 days at concentrations of 0, 0.375, 0.75, 1.5, 3 and 6 mg/L PFOS, and 0, 1.25, 2.5, 5, 10 and 20 mg/L PFOA, respectively. Acute toxicity was assessed on the basis of immobility, while chronic toxicity was assessed on the basis of fecundity. The acute toxicity test on PFOS and PFOA showed that the values of $EC_{50}$ were 50.90 mg/L and 253.47 mg/L, respectively. In the chronic test, fecundity was reduced significantly at 1.5 mg/L of PFOS and 10 mg/L of PFOA, respectively. These results indicated that PFOS is more toxic to zooplankton than PFOA, and both chemicals have some hazard demonstrates risk for acute or chronic toxicity to freshwater organism.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.12a
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• pp.124-126
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• 2005

Aquatic ecotoxicity of bisphenol A, a well known endocrine disrupter in mammals, was studied using lab. reared Daphnia magna as a test organism. The static acute 48h $LC_{50}$ of bisphenol A was 12.9mg/L and 110-hr $LC_{50}$ values of bisphenol A for daphnid embryos of different ages after deposition into the brood chamber increase with ages in the range of 1.55mg/L-8.91mg/L. Bisphenol A showed the ability to inhibit embryonic development. The lethal response and developmental inhibition all showed good concentration-response relationship.

• Fibers and Polymers
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• v.7 no.1
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• pp.30-35
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• 2006

The influences of a series of new azo direct dyes including copper-complexes based on benzidine congeners, 2,2'-dimethyl-5,5'-dipropoxybenzidine and 5,5'-dipropoxybenzidine, were examined using microorganism, Daphnia magna. The purpose of the research described in this paper was to use bioassays with daphnids to determine the aquatic toxicity of new azo dyes in which copper was incorporated. The results clearly show that copper has negative effects to aquatic ecosystem as expected. The study also suggested that the assay with Daphnia magna was an excellent method to evaluate the influences of dyes to the aquatic environment.

• Environmental Analysis Health and Toxicology
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• v.21 no.1 s.52
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• pp.81-86
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• 2006

Embryotoxicity tests were performed in Daphnia magna to assess aquatic ecotoxicity of bisphenol A, a well known industrial compound showing estrogen-like activity in vivo, and to examine their effectiveness in the toxicological assessment. The whole embryonic developmental period was classified into 6 stages and developmental abnormality was checked to evaluate the embryotoxicity. In the present study, bisphenol A showed the ability to interfere with embryonic development, suggesting its antiecdysteroidal activity. The rates of mortality, delayed development, deformity and immobility all showed good concentration-response relationship, demonstrating their possibility as useful toxicological indices in daphnid embryotoxicity tests that have been rarely performed so far. It seemed favorable to the test sensitivity that embryos are removed from maternal daphnids around 7 hr after deposition from the ovaries to the brood chamber. These results suggest that daphnid embryotoxicity tests can be one of useful tools available for the assessment of ecotoxicity of various chemicals in the aquatic environment.