• Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.77-81
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• 2012

We assessed the toxicity of cryoprotectant agents (CPAs) to gametophytic thalli of red alga Porphyra yezoensis at room temperature. The CPAs used were: dimethyl sulfoxide (DMSO), ethylene glycol (EG), glycerol (GC), 1,2-butanediol (1,2-BD), 1,3-butanediol (1,3-BD), 2,3-butanediol (2,3-BD), 1,3-propanediol (1,3-PD) and propylene glycol (PG). CPA concentrations of 10, 15, 20, 25, 30, 35, 40, 45, and 50% were employed with 30 or 60 s immersion. The toxicity of the eight CPAs to gametophytic thalli of P. yezoensis was in the order: 1,3-BD < DMSO ${\approx}$ 2,3-BD ${\approx}$ PG ${\approx}$ EG < GC < 1,3-PD ${\approx}$ 1,2-BD. All thalli were more sensitive to high CPA concentrations, and most (>75%) thalli survived exposure to 10-25% CPA for 60 s. These data will facilitate selection of the optimal cryoprotectant concentration for cryopreservation of P. yezoensis thalli.

• Journal of Environmental Health Sciences
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• v.45 no.3
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• pp.285-294
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• 2019

Objectives: For suitable risk management of the domestic aquatic environment, it is necessary to conduct toxicity tests using species native to Korea. In the present study, we performed toxicity ring tests using endemic freshwater arthropoda Neocaridina denticulata and evaluated its validity and reproducibility as an international standard test species. Methods: To evaluate the sensitivity levels of N. denticulata to hazardous chemicals, toxicity values for several chemicals were compared with other standard test species. Intra- and inter-laboratory acute toxicity tests were performed both within a single laboratory and among four laboratories respectively using 3,4-Dichloroaniline, which is generally used as a reference test substance in fish toxicity tests. In addition, intra- and inter-laboratory coefficient of variations (CVs) were calculated to evaluate reproducibility based on the estimated toxicity values. Results: The sensitivity of N. denticulata to several chemicals was found to be similar with D. manga, indicating that the species is valid as a test species. The CVs of the intra- and inter-laboratory tests were 22.946% with four qualified runs and 8.828% among the four laboratories, respectively. Conclusions: N. denticulata serves in an important role in the food chain of Korean aquatic ecosystems and also inhabits several other Asian countries. Since the validity and reproducibility of the species were confirmed as a toxicity test species in this study, further efforts are needed to establish N. denticulata as the international standard test species for the appropriate risk assessment of aquatic ecosystems at home and abroad.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.176-178
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• 2000

The toxicity of muscle in pufferfish, Tikifugu vermicularis radiatus is known to be weak. However, no food poisoning has reported in this species although market consumption has been relatively high in Korea, especially on western coastal area. It presumes that there could be different toxicity in fish muscle of fresh and frozen specimens. In this regard, the frequency of toxic fish, the toxicity level in fresh and frozen fish as well as highest toxicity ann average toxicity were investigated. From the results, weak toxicity was detected in frozen fish muscle whereas no toxicity was measured in fresh fish. According to this, it is suggested that the toxicity of frozen and fresh fish must be tested simultaneously when tonicity of pufferfish is investigated. The above results implicate that toxicity of pufferfish may be due to the phsyical treatment such as freezing or thawing process.

• Journal of fish pathology
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• v.33 no.1
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• pp.45-53
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• 2020

Doxycycline is a semi-synthetic broad-spectrum antibiotic, and it has been used to get rid of bacteria in animals and humans. The use of antibiotics has greatly contributed to the aquaculture production although its misuse sometimes presents public health problems. This study was performed to investigate the toxic effects of doxycycline on whiteleg shrimp (Litopenaeus vannamei) administered for possible infection treatments. The shrimp were allocated into four groups and doxycycline was fed three times a day for 7 days at 0, 20, 50 and 100 mg/kg to each group. After 24 hr following the 7-day treatment, hemolymph and hepatopancreas were used for blood and biochemical analysis: Total hemocyte counts, Total protein, Total cholesterol, Gluscose, Glutamic pyruvic transaminase, Glutamic oxaloacetic transaminase, Glutathione peroxidase, Superoxide dismutase, Glutathione-s-transferases, Total antioxidant capacity colorimetric and Acid phosphatase. In addition, histopathological examination was performed on the hepatopancreas and muscle. It was observed that body weight gain was significantly retarded in 100 mg/kg doxycycline group. Doxycycline was found to induce biochemical or functional disorders at 100 mg/kg as observed many of the blood and biochemical parameters were significantly reduced. In conclusion, it was judged that there will be no major toxicity problems with doxycycline when used for shrimp aquaculture at regular doses.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2005.12a
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• pp.96-97
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• 2005

• 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.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.103-112
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• 2011

Aquatic contamination by organic pollutants has been a suspected reason for rapid decrease of amphibian populations whose embryonic and larval stages are in an aquatic environment. Amphibian embryos can be a useful model to study the ecoctoxicologial impacts of aquatic pollutants. The obtained toxicological data are useful references for the management of aquatic pollutants in public health because amphibia share many developmental events with terrestrial vertebrates including humans. Safety guidelines for the toxicological effects of aquatic contaminants of chemicals identified as hazardous should be addressed at multiple endpoints. Alkylphenols have been widely-used in agricultural, industrial, and household activities; they contaminate and can persist in aquatic environments. Exposure to alkylphenols results in endocrine disruption in aquatic animals. In this review, we summarize the developmental toxicities of alkylphenols in amphibian embryos and larva according to the exposure route, chemical concentration, duration of exposure, and affected developmental stage together with mechanisms of toxicity and typical patterns of developmental abnormality. The merits of amphibian embryos as a toxicity test model for mid- to long-term exposure to aquatic pollutants are discussed proposed.

• Journal of Environmental Health Sciences
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• v.45 no.2
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• pp.192-202
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• 2019

Objectives: According to the central limit theorem, the samples in population might be considered to follow normal distribution if a large number of samples are available. Once we assume that toxicity dataset follow normal distribution, we can treat and process data statistically to calculate genus or species mean value with standard deviation. However, little is known and only limited studies are conducted to investigate whether toxicity dataset follows normal distribution or not. Therefore, the purpose of study is to evaluate the generally accepted normality hypothesis of aquatic toxicity dataset Methods: We selected the 8 chemicals, which consist of 4 organic and 4 inorganic chemical compounds considering data availability for the development of species sensitivity distribution. Toxicity data were collected at the US EPA ECOTOX Knowledgebase by simple search with target chemicals. Toxicity data were re-arranged to a proper format based on the endpoint and test duration, where we conducted normality test according to the Shapiro-Wilk test. Also we investigated the degree of normality by simple log transformation of toxicity data Results: Despite of the central limit theorem, only one large dataset (n>25) follow normal distribution out of 25 large dataset. By log transforming, more 7 large dataset show normality. As a result of normality test on small dataset (n<25), log transformation of toxicity value generally increases normality. Both organic and inorganic chemicals show normality growth for 26 species and 30 species, respectively. Those 56 species shows normality growth by log transformation in the taxonomic groups such as amphibian (1), crustacean (21), fish (22), insect (5), rotifer (2), and worm (5). In contrast, mollusca shows normality decrease at 1 species out of 23 that originally show normality. Conclusions: The normality of large toxicity dataset was not always satisfactory to the central limit theorem. Normality of those data could be improved through log transformation. Therefore, care should be taken when using toxicity data to induce, for example, mean value for risk assessment.

• ALGAE
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• v.32 no.2
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• pp.131-137
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• 2017

Although green algae of the genus Closterium are considered ideal models for testing toxicity in aquatic ecosystems, little data about the effects of toxicity on these algal species is currently available. Here, Closterium ehrenbergii was used to assess the acute toxicity of copper (Cu). The median effective concentration ($EC_{50}$) of copper sulfate based on a dose response curve was $0.202mg\;L^{-1}$, and reductions in photosynthetic efficiency ($F_v/F_m$ ratio) of cells were observed in cultures exposed to Cu for 6 h, with efficiency significantly reduced after 48 h (p < 0.01). In addition, production of reactive oxygen species significantly increased over time (p < 0.01), leading to damage to intracellular organelles. Our results indicate that Cu induces oxidative stress in cellular metabolic processes and causes severe physiological damage within C. ehrenbergii cells, and even cell death; moreover, they clearly suggest that C. ehrenbergii represents a potentially powerful test model for use in aquatic toxicity assessments.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.155-160
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• 1999

Studies on detoxification of Paralytic Shellfish Poison (PSP)-infested oyster, Crassostrea gigas were carried out using available processing resources. Changes of paralytic shellfish toxin components and specific toxicity during canning process were also investigated with high performance liquid chromatography (HPLC). Toxic oysters collected at Hachong in Koje Bay were used for experimental samples. The toxicity of oysters with range of 185-778 ug/100g was reduced below the quarantine limit of 80 ug/100g or not detected level by the mouse bioassay after canning process. The mole $\%$ of toxin components in the shucked oyster was in the order of 25.1 mole $\%$ of gonyautoxin 1, 19.2 mole $\%$ of gonyautoxin 3, 17.2 mole $\%$ of gonyautoxin 4 and 14.6 mole $\%$ of gonyautoxin 2. This sample had tracing amounts of Cl, C2, saxitoxin and neosaxitoxin. In the case of specific toxicity, the major toxins were consisted of gonyautoxin 1-4. The sum of gonyautoxin 1, 2, 3 and 4 was 80% of total toxicity of oyster. Saxitoxin and decarbamoylsaxitoxin were the more thermostable than any other toxin components.