• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.1
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• pp.31-41
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• 2018

Seaweeds are composed of a variety of bioactive substances, including polysaccharides, pigments, minerals, peptides, and polyphenols. Among these substances, the arsenic content of seaweeds has been a significant cause for concern. The present study evaluated the toxicity of arsenic from three species of seaweed using a zebrafish Danio rerio model. The arsenic-rich extracts were obtained from Ecklonia cava (ECAE), Undaria pinnatifida (UPAE) and Hizikia fusiformis (HFAE) using a solvent of 50% methanol and 1% $HNO_3$. We investigated the toxicity of the arsenic-rich extracts in zebrafish embryos through survival rate, heart rate, yolk sac edema size, cell death, reactive oxygen species (ROS) production and real-time polymerase chain reaction (PCR). The hepatotoxicity of arsenic-rich extracts was assessed in the liver of adult zebrafish through real-time PCR and histopathology. The survival rates of embryos and adult zebrafish showed no significant changes at any concentration. At 100 ppm, embryos did not exhibit significant differences in heart rate, yolk sac edema size, cell death or ROS production. In addition, apoptosis-related genes in larvae and liver tissue were unaffected by treatment with arsenic-rich extracts. These data will help clarify that developmental changes, hepatic oxidative stress, and apoptosis are not associated with toxicity from arsenic-rich seaweed extracts in a zebrafish model.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1997.12a
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• pp.47-71
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• 1997

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1996.12a
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• pp.44-44
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• 1996

• Fisheries and Aquatic Sciences
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• v.20 no.7
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• pp.12.1-12.7
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• 2017

Soft tunic syndrome (STS) is a protozoal disease caused by Azumiobodo hoyamushi in the edible ascidian Halocynthia roretzi. Previous studies have proven that combined formalin-hydrogen peroxide ($H_2O_2$) bath is effective in reducing STS progress and mortality. To secure target animal safety for field applications, toxicity of the treatment needs to be evaluated. Healthy ascidians were bathed for 1 week, 1 h a day at various bathing concentrations. Bathing with 5- and 10-fold optimum concentration caused 100% mortality of ascidians, whereas mortality by 0.5- to 2.0-fold solutions was not different from that of control. Of the oxidative damage parameters, MDA levels did not change after 0.5- and 1.0-fold bathing. However, free radical scavenging ability and reducing power were significantly decreased even with the lower-than-optimal 0.5-fold concentration. Glycogen content tended to increase with 1-fold bathing without statistical significance. All changes induced by the 2-fold bathing were completely or partially restored to control levels 48 h post-bathing. Free amino acid analysis revealed a concentration-dependent decline in aspartic acid and cysteine levels. In contrast, alanine and valine levels increased after the 2-fold bath treatment. These data indicate that the currently established effective disinfectant regimen against the parasitic pathogen is generally safe, and the biochemical changes observed are transient, lasting approximately 48 h at most. Low levels of formalin and $H_2O_2$ were detectable 1 h post-bathing; however, the compounds were completely undetectable after 48 h of bathing. Formalin-$H_2O_2$ bathing is effective against STS; however, reasonable care is required in the treatment to avoid unwanted toxicity. Drug residues do not present a concern for consumer safety.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.467-472
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• 2012

In this study, water quality and acute toxicity using Daphnia magna were analyzed to investigate the eco-toxicological substances identified as statistical analysis and propose a management plan for the effluent of Banwol industrial complex, Ansan, Gyeonggi-do. Cu, Zn, F, Mn concentrations in the effluent far exceeded the US standards to protect the aquatic ecosystem and eco-toxicity values were 5 ~ 22 TU. However, concentrations of heavy metals significantly decreased after Ansan public wastewater treatment plant operating a biological treatment and toxicity values were 0 TU. Zn, Cr, F and Cu in the effluent showed very strong and strong positive correlations with eco-toxicity values, respectively. Regression analysis resulted in an equation between toxicity and Zn, TU = $4.884{\times}Zn$ (mg/L) -0.391 showing Zn concentration should be managed less than 0.285 mg/L to keep the eco-toxicity (TU) less than 1.

• Environmental Analysis Health and Toxicology
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• v.18 no.4
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• pp.305-310
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• 2003

A rapid, inexpensive enzymatic method is proposed for indirect water quality testing in terms of heavy metal toxicity. The activity of glucose-6-phosphate dehydrogenase was applied for heavy metal toxicity test as an effective criterion in water quality. The toxicity of Pb (lead) and Cd (cadmium) for water flea, Moina macrocopa, were evaluated for 2-8 days with variables of mobilization ability. And the reproduction impairment of Moina macrocopa were investigated as the parameter of chronic toxicity test for Pb and Cd. As a result, the EC$_{50}$ for immobilization of Moina macrocopa were Pb and Cd were 1.6749 and 0.4683, respectively. The values of reproductive impairment to Moina macrocopa for Pb and Cd were 9.5938 and 8.3264 in EC$_{50}$ A significant alteration of G6PDH (Glucose-6-phosphate dehydrogenase) activity of Moina macrocopa was observed when Cd and Pb were treated in media. The results obtained indicate that G6PDH activity of Moina macrocopa can be used as an indicative parameter in aquatic toxicity tests for heavy metals.als.

• ALGAE
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• v.27 no.4
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• pp.303-313
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• 2012

Cyanobacteria are well known for their production of a multitude of highly toxic and / or allelopathic compounds. Among the photosynthetic microorganisms, cyanobacteria, belonging to the genus Nostoc are regarded as good candidate for producing biologically active secondary metabolites which are highly toxic to humans and other animals. Since so many reports have been published on the poisoning of different animals from drinking water contaminated with cyanobacteria toxins, it might be assumed that bioactive compounds are found only in aquatic species causes toxicity. However, the discovery of several dead dogs, mice, ducks, and fish around paddy fields, prompted us to study the toxic compounds in a strain of Nostoc which is most abundant in the paddy fields of Iran, using polymerase chain reaction and liquid chromatography coupled with a diode array detector and mass spectrophotometer. Results of molecular analysis demonstrated that the ASN_M strain contains the nosF gene. Also, the result of ion chromatograms and $MS^2$ fragmentation patterns showed that while there were three different peptidic compound classes (anabaenopeptin, cryptophycin, and nostocyclopeptides), there were no signs of the presence of anatoxin-a, homoanatoxin-a, hassallidin or microcystins. Moreover, a remarkable antifungal activity was identified in the methanolic extracts. Based on the results, this study suggests that three diverse groups of potentially bioactive compounds might account for the death of these animals. This case is the first documented incident of toxicity from aquatic cyanobacteria related intoxication in dogs, mice, and aquatic organisms in Iran.

• Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.253-260
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• 2013

We investigated the toxicological effects of Aroclor 1254 on the fertilized eggs, embryos and larvae of the olive flounder Paralichthys olivaceus. The survival rate and hatching success of the embryos decreased significantly in treated groups in an Aroclor 1254-dose-dependent manner. Significant differences were found at ${\geq}5{\mu}g/L$ Aroclor 1254 compared to the control group. Hatching success occurred at ${{\leq}}10{\mu}g/L$ Aroclor 1254, which was not significantly different to the control. Embryo malformation increased significantly at ${\geq}1{\mu}g/L$, and included yolk-sac and tail-flexure abnormalities. There was a significant decrease in the survival rate of the larvae at ${\geq}5{\mu}g/L$, which was accompanied by the malformations described above. Notably, concentrations as low as $1{\mu}g/L$ caused a significant increase in abnormalities in the larvae, including incidences of multi-focal hemorrhages, pericardial and yolk-sac edema, inhibition of swim bladder inflation and severe developmental delay. The responses to Aroclor 1254-induced toxicity were generally similar among fertilized eggs, embryos and larvae from three separate flounder hatcheries: Cheju Island, Yeosu and Chungnam, South Korea. These results indicate the high acute toxicity of Arolcor 1254 concentrations of which as low as $1{\mu}g/L$ in olive flounder larvae can affect unhatched embryos. To conclude, the average $LC_{50}$ values for Aroclor 1254 in the embryos and larvae were 50.92 and $3.08{\mu}g/L$, respectively. Additionally, the average $EC_{50}$ values, based on the rate of damage were 14.72 and 5.6$1{\mu}g/L$, respectively.

• Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.220-227
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• 2005

The estrogenic phenolic compounds, nonylphenol (NP), octylphenol(OP), bisphenol A (BPA) and nonylphenol mono- and diethoxylate ($NP_{1-2}EO$) were analyzed in 24 surface water samples from six rivers flowing into Masan Bay. All of the phenolic compounds were detected in all six rivers in high concentrations. The most abundant compound was $NP_{1-2}EO$ (86.0%), followed by NP ($10.1 \%$), BPA ($3.6\%$) and OP ($0.3\%$). The levels of phenolic compounds were 1.42-22.70 ${\mu}g$/L for $NP_{1-2}EO$, 0.15-1.68 ${\mu}g$/L for NP, 0.024-0.610 ${\mu}g$/L for BPA and 0.003-0.067 ${\mu}g$/L for OP. Especially, high concentrations were recorded in the rivers that pass through industrial complexes. The concentrations of phenolic compounds observed in these river waters were 1-2 orders of magnitude lower than the reported acute toxicity levels (hundreds of micrograms per liter). However, they were only slightly lower than the chronic toxicity levels. Most of the water samples also exceeded the Canadian nonylphenolic compounds water quality guideline, 1 ${\mu}g$/L, for the protection of aquatic life and the maximum permissible concentrations (MPC), 0.33 ${\mu}g$/L for NP and 0.12 ${\mu}g$/L for $NP_{1-2}EO$.

• Journal of Wetlands Research
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• v.2 no.1
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• pp.69-85
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• 2000

Wetlands are generally thought to be among the most fertile and productive ecosystems of the world. They provide a variety of ecological functions to the landscape. In recent years there has been considerable research activity to generate more scientific documentation on the ecological functions of wetlands. Many pollutants released to the environment settle and accumulate in the silt and mud called sediment on the bottoms of wetlands. Contaminated sediment can cause adverse effects to aquatic organism and eventually to ecological system. Sediment toxicity test with water fleas has been done by standardized preparation method of pore and elutriate water methods described in the literature for the need to protect Woopo wetlands. The results of Daphnia magna, Ceridaphnia dubla and Simocephalus sp. toxicity test were compared and discussed in terms of the relative sensitivity and discrimination abilities with both pore and elutriate water obtained from the sediments of Woopo wetlands.