• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.4
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• pp.298-304
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• 1999

Toxic effect of landfill leachate on the larvae and juvenile stage of the river puffer fish, Takifugu obscurus, were investigated in order to assess severity of environmental impact of leachate effluent on the general population of estuarine fishes. A short-term toxic experiment was designed to test both laboratory hatched larvae and juveniles (5, 10 and 15 mm in length) and in-situ juveniles (30 and 45 mm in length) using the leachate concentrations between 0 and 16%. Lethal concentrations of 50% mortality ($LC_{50}$) were observed using Spearman-karber Method. 24hr-$LC_{50}$ appeared at the leachate concentrations ranging from 3.03 to 8.57%, 48hr-$LC_{50}$ at 2.73 to 6.21 %, 72hr-$LC_{50}$o at 2.45 to 5.53%, and 96hr-$LC_{50}$ at 2.38 to 4.93%, respectively. Leachate concentrations between 0.69 and 1.51% induced 96hr-$LC_1$. Respiratory frequency was significantly affected even at low leachate concentrations between 0.5 and 1.0% (P < 0.05). These results suggest that the leachate effluents may cause a harmful impact on the physiology of river puffer fish, especially for younger cohorts.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.529-534
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• 1994

The lethal concentration(LC50) of several micropollutants for three species of the fish Paralichthys olivaceus, Mugil cephalus and Sebastes schlegeli were determined by acute toxicity tests. For the determination of definitive test concentrations, the fish were exposed to three test material concentrations spaced at order-of-magnitude intervals based on a logarithmic ratio in range finding tests. LC50 was determined by five concentrations of test material in a geometric progression by means of range finding tests. The 96hr-LC50 values(mg/l) were estimated by the graphical interpolation of probability-logarithm transformations. These indicated that the order of sensitivities to three kind of micropollutants was Mugil cephalus > Paralichthys olivaceus > Sebastes schlegeli.

• Journal of Aquaculture
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• v.11 no.4
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• pp.429-435
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• 1998

This study compared acute ammonia toxicity in juvenile rockfish and red sea bream. Oxygen concentration affected ammonia toxicity to aquatic animals. Without aeration, the 96-hr $LC_50$ values of $NH_4^+$and un-ionhized ammonia for juvenil rockfish(3.6g, 6.6cm) were 2.61 and 0.09 mg/l, respectively. The 3-hr $LC_50$ values of $NH_4^+$ for the size of 1.9g (5.2cm) and 3.6g (6.6cm) rockfish, and 1.0g (3.8cm) and 2.0g (5.0cm) red sea bream without aeration were 3.96, 3.94, 4.35 and 3.75 mg/l, respectively. When oxygen level was low, larger fish were more susceptible to ammonia toxicity than smaller one because of stress resulted from low oxygen. However, with aeration, the 96-hr $LC_50$ values of $NH_4^+$ for the size of 1.2g (3.9cm) and 2.3g (5.1cm) red sea bream with aeration were 3.84 and 3.90mg/l, respectively. The 6-hr $LC_50$values of $NH_4^+$ for the size of 3.1g (5.9cm) and 6.2g (7.0cm) rockfish with aeration were 3.83 and 3.94 mg/l, respectively. When oxygen level was high, larger rockfish and red sea bream were less susceptible to ammonia toxicity than smaller ones. The 6 hr-or 96 hr-$LC_50$ values of $NH_4^+$for rockfish with reduced ammonia toxicity. In comparing 96 hr-$LC_50$ values of $NH_4^+$ and un-ionized ammonia for juvenil rockfish with those for juvenil red sea bream, the values for rockfish were lower than for red sea bream. This indicates that juvenile rockfish is more susceptible to ammonia toxicity than juvenile red sea bream.

• Journal of Food Hygiene and Safety
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• v.15 no.2
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• pp.137-143
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• 2000

The present study was performed to investigate the bioconcentration of phosphamidon and profenofos. The BCFs(bioconcentration factors), depuration rate constants and LC$_{50}$ for two pesticides in zebrafish(Brachydanio rerio) were measured by the flow-through system(OECD guideline 305). The results obtained are summarized as follows: The 24-hrs LC$_{50}$, 48-hrs LC$_{50}$, 72-hrs LC.n and 96-hrs LC$_{50}$ were more than 100 mg/l for phosphamidon. The concentration of phosphamidon in zebrafish reached an equilibrium in 12 hrs at low and high concentrations(0.2 mg/l and 1 mg/1). The average BCF values of phosphamidon were less than 1 at low(0.96, n=7) and high concentrations (0.89, n=7) after 12~168 hrs. Depuration rate constants of phosphamidon were 0.18 hr-1 and 0.21 hr-1, half-life of phosphamidon were 3.85 and 3.30 at low and high concentrations(0.2 mg/l and 1 mg/l), respectively, The concentrations of phosphamidon in zebrafish at low and high concentrations were rapidly decreased after 8(0.04 $\mu\textrm{g}$/g) and 12 hrs(0.07 $\mu\textrm{g}$/g). The 24-hrs LC$_{50}$, 48-hrs LC$_{50}$, 72-hrs LC$_{50}$ and 96-hrs LC$_{50}$ were 2.9, 2.6, 2.2 and 2.0 mg/1 for profenofos. The concentration of profenofos in zebrafish reached an equilibrium in 12 hrs at five-hundredth and one-hundredth concentration of 96-hrs LC$_{50}$(0.004 mgA and 0.02 mg/1). The average BCF values of profenofos were 141.9(n=7) and 111.3(n=7) at five-hundredth and one-hundredth concentration of 96-hrs LC$_{50}$(0.004 mg/l and 0.02 mg/1) after 12~168 hrs. Depuration rate constants of profenofos were 0.09 hr$^{-1}$ and 0.10 hr$^{-1}$, half-life of profenofos were 7.70 and 6.93 at five-hundredth and one-hundredth concentration of 96-hrs LC50(0.004 mg/l and 0.02 mg/1), respectively. The concentrations of profenofos in zebrafish at five-hundredth and one-hundredth concentration of 96-hrs LC$_{50}$ decreased agter 8(0.18 $\mu\textrm{g}$/g) and 12 hrs (0.19 $\mu\textrm{g}$/g). The LC$_{50}$ value in zebrafish showed that acute toxicity of profenofos was higher than that of phosphamidon. The BCF values of profenofos were 100 times higher than those of phosphamidon, and depuration rate of phosphamidon was two times faster than that of profenofos.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.139-142
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• 1984

Short-term acute toxicity of synthetic detergent(LAS) to larvae of loach, Misgurnus angillicaudatus was examined by static bioassay. The larvae were exposed to 15 different concentration of synthetic detergent for 16, 48, 72, 96 and 120 hours in order to determine median lethal concentration($LC_{50}$). The $100\%$ mortarlity of larvae was showed within 120, 96, 48 and 16 hours for 6, 18, 30 and 38 ppm, respectively. The median lethal concentration values of the larvae were 12.59 ppm for 48 hours, 4.00 ppm for 96 hours and 1.02 ppm for 120 hours. The permissible toxicant concentration of acute toxicity to larvae was $0.37{\sim}0.43$ ppm, and application factor of the synthetec detergent was $0.093{\sim}0.108$. The median lethal time($LT_{50}$) for different concentration also was determined. The $LT_{50}$ of 0.2 ppm was found within 165.1 hours and 2 ppm was 106.2 hours, while the $LT_{50}$ of 8 ppm was 60.3 hours and that of 38 ppm was 23.5 hours.

• Korean Journal of Ecology and Environment
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• v.39 no.4 s.118
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• pp.419-423
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• 2006

In this study, acute toxicity of four pesticides (diazinon, iprodione, fenproparthrin, and myclobutanil) to Chinese bleak, Aphyocypris chinensis, and to study their adverse effects were conducted in static systems. The 96-hr $LC_{50}$ values were determined, as well as 95% confidence limits. The 96-hr $LC_{50}$ values of these chemicals derived for Chinese bleak were rank ordered from the most toxic to the least toxic technicals as follows: Fenproparthrin (0.003 mg $L^{-1}$)>Myclobutanil (9.1 mg $L^{-1}$)>Diazinon (14.1 mg $L^{-1}$)>Iprodione (31.8 mg $L^{-1}$), The data presented in this study indicate the acute toxicity tests carried out on only one fish species may lead to erroneous determination of water quality criteria and classification of test chemicals for environmental management and regulatory purpose. Therefore, more studies comparing the susceptibility of a variety of fish species to various toxicants are needed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.488-495
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• 1997

The effects of ammonia on survival and growth of the flounder larva, Paralichthys olivaceus, were examined by a static renewal bioassay method. The $96\;hr-LC_{50}$ with the developmental stages during the period from 1day to 23 day-old larvae ranged 0.273 to 1.023 mg $NH_3/\ell$. Tolerance of the larvae to ammonia toxicity was much sensitive at the early larval stage, and increased with the growth of the larvae. Threshold $96hr-LC_{50}$ in 1, 3 and S day-old larvae after hatching were 0.293, 0.248 and 0.379 mg $NH_3/\ell$, respectively. Survival rate and growth in body weight and body weight of the larva were reduced with increase of ammonia concentration in the range of 0.055 and 0.341 mg $NH_3/\ell$. The no-observable-effect concentration (NOEC) and lowest-observable- effect concentration (LOEC) of the flounder larve were 0.102 and 0.174 mg $NH_3/\ell$ for body length, and 0.151 and 0.198 mg $NH_3/\ell$ for body weight, respectively. Chronic value (ChV), which is the geometric mean of the NOEC and $NH_3/\ell$ to body length of the larvae were 0.124 mg $NH_3/\ell$. The coefficient of variation (CV) for body length was higher at high concentration than at low concentration.

• Journal of fish pathology
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• v.10 no.1
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• pp.65-72
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• 1997

In the present study, acute toxicity data were obtained for hydrogen sulfide to larvae and adults of blue crab Portunus trituberculatus, white shrimp Metapenacus monoceros and prawn Macrobrachium nipponense under continuous flow through system. The larvae 96hr-$LC_{50}$ values of hydrogen sulfide were 7.3, 9.3 and $9.0{\mu}g/\ell$ for P. trituberculatus, M. monoceros and M. nipponense respectively. The larval sensitivity of the three crustaceans studied for the hydrogen sulfide was in the order of P. trituberculatus> M. nipponense> M. monoceros. The adults 96hr-$LC_{50}$ values of hydrogen sulfide were 42.5, 37.8 and $56.6{\mu}g/\ell$ for P. trituberculatus, M. monoceros and M. ripponense, respectively. The order of toxicity of hydrogen sulfide to adults of the three crustaceans was P. tritruberculatus> M. monoceros> M. nipponense. The larval/adult ratios of hydrogen sulfide toxicity were 5.8, 4.1 and 6.3 for P. trituberculatus M. monoceros and M. nipponense respectively, and larvae were found to be more sensitive to hydrogen sulfide than adults in all cases.

• 한국해양학회지
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• v.13 no.1
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• pp.35-43
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• 1978

Short-term acute toxicity of mercury, cadmium and copper to arkshell, Anadara broughtonii, and to oyster, Crassostrea gigas, was determinedby static bioassays from 20 May to 27 June in 1977. During the observations of the opening rate of the shell mercury was the most sensitive toxicant of the three toxic substances to the test animals and caused them to close their shellvalves together after being exposed to a mercury solution for an hour during the test. Opening rate to cadmium and copper increased gradually at the higher concentration. the 96hr-LC50 values for the test animals are 4.84mg/l for mercury and 1.86mg/l for cadmium, while the 72hr-LC50 value for copper is 0.31mg/l. the death rate of oysters for cadmium showed lower than that of the mercury and copper test solutions. The 96hr-LC50 values of mercury, copper and cadmium were 1.1mg/l, 2.54mg/l and 19.5mg/l, respectively. For oysters mercury was the most toxic substance, and cadmium was the least toxic one. the medium lethal time (LT 50) value decreased gradually at higher concentration of heavy metals. The LT 50 of 2mg/l was found within 96 hours ofr copper, 104 hours for mercury and 121 hours for cadmium. The lethal threshold concentrations for 7 days were found to be about 1mg/l for mercury and copper, and 2mg/l for cadmium.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.164-169
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• 2003

Organotins are widely used organometals in various agricultural and industrial purposes. After introduction of these chemicals to the aquatic environment, they are degraded by abiotic and biotic precesses. The triorganotin compounds are sequentially degraded to di-organotin, mono-organotin and then finally inorganic tin. Although the effects of trialkyltin an marine organisms have been intensively studied, little has been known on plankton as a producer of ecosystem. In this paper, the toxicities of dibutyltin (DBT), monobutyltin (MBT), diphenyltin (DPT), monophenyltin (MPT), trimethyltin (TMT) and dimethyltin (DMT) to rotifer Brachionus plicatilis were measured, and their potencies were compared based on 96 hr-$LC_{50}$ value. The results showed that DPT (13.8 ppb) was the highest toxic, which was followed by TMT (42.9), DBT (80.6), MPT (262.2), MBT and DMT (>1,000) in order. Thus, in tri- and diorganotins, the toxicity was observed phenyltins > butyltins > methyltins, and in mono-organotins phenyltins was more toxic than butyltins. Considering the order of 96 hr--$LC_{50}$ with octanol-water eoefficients ($K_{ow}$) in organotins together, it was considered that the toxicity of organotins seems to be related to the lipophilicity of the compounds.