• Journal of Aquaculture
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• v.16 no.3
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• pp.151-158
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• 2003

This study was conducted to estimate the effects of residual chlorine dioxide ($CIO_2$) in chlorinated seawater on survival and physiological responses (hematocrit: Ht, hemoglobin: Hb, serum electrolyte and glucose levels, and osmolality) of olive flounder, Paralichthys olivaceus. All the flounders were exposed for 10 min to different concentrations of residual $CIO_2$ just after chlorination for 1 min in each experimental aquarium (EA). ClO$_2$-free seawater was continuously supplied to each EA after 10 min exposure to $CIO_2$. By means of probit analysis, the median lethal times (LT$_{50}$, min) of flounder exposed to 0.43 and 0.51 ppm $CIO_2$, were at 103 and 32 min, respectively. In the range from 0.34 to 0.51 ppm $CIO_2$, the values of Ht, Hb, electrolytes and osmolality of fish exposed to $CIO_2$ were significantly elevated as elapsed time and residual concentrations of $CIO_2$ increased after chlorination. The levels of Ht, Hb, electrolytes and osmolality in flounder exposed to 0.27 ppm $CIO_2$ were not significantly different compared to control fish, which were maintained in $CIO_2$-free seawater; however, the levels of serum glucose were significantly increased with elapse times.

• Environmental Analysis Health and Toxicology
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• v.20 no.2 s.49
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• pp.133-141
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• 2005

다양한 유해오염물질에 급성 노출된 단각류 Monocorphium acherusicum의 노출 기간 이후에 발생하는 지연 사망(latent mortality)이 반수치사농도(LC5O)산출에 어떤 영향을 미치는 지를 규명하기 위한 일련의 실험이 수행되었다. 본 연구에서는 실험생물을 카드뮴, 구리, 수은과 같은 중금속, tributyltin(TBT), 암모니아 그리고 방향성탄화수소인 phenanthrene에 각각 96시간 동안 노출시킨 후 깨끗한 해수에 옮겨 다시 6일 동안 배양하면서 사망률을 조사하였다. 실험결과 구리, TBT, 암모니아, phenanthrene과 같은 물질에 노출된 M. acherusicum의 사망률은 노출이 끝난 이후에도 계속적으로 증가하는 지연 사망이 관찰되었으며, 이에 따라 기존의 방법_으로 산출된 96-h LC50보다 지연 사망을 고려한 새로운 LC50이 크게 낮아지는 경향이 관찰되었다. 지연사망률을 고려하지 않은 기존의 독성시험 결과는 지연 사망의 영향을 반영하지 못하므로 실제 현장에서 발생할 수 있는 오염물질의 영향을 과소평가 할 가능성이 있다. 따라서 지연 사망률에 대한 고려는 실제 현장 개체군에 대한 유해오염물질의 영향을 보다 정화하게 예측하는 데에 활용될 수 있을 것이다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.119-123
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• 1979

The cute toxicity test of mercury, cadmium and copper to yellowtail, Seriola quinqueradia, and to rock-bream, Oplegnathus fasciatus, were conducted by static bioassays from 18 July to 27 October, 1978. In the tests, tile least sensitive heavy metals were cadmium to rock bream and copper to yellowtail. The test species were most sensitive to mercury among all the chemicals used. The 24hr-LC 50 value for the yellowtail was 0.11mg/l for mercury, 0.82mg/l for cadmium and 1.03mg/l for copper. While the 48hr-LC 50 value for the rock bream was 1.40mg/l for mercury and 1.73mg/l for copper.

• Environmental Analysis Health and Toxicology
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• v.18 no.1
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• pp.21-25
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• 2003

카바메이트계 농약인 카보푸란은 어류에 대한 독성이 매우 높으며, 낮은 농도에서 어류의 척추기형이나 행동이상을 유발한다. 이러한 카보푸란의 독성기전을 밝히기 위한 일환으로 신경물질대사와 관련이 깊은 acetylcholine esterase(AChE)와 monoamine oxidase(MAO)에 미치는 농약의 효과를 송사리(Oryzias latipes; Medaka fish)를 이용하여 평가하였다. Medaka fish에 대한 카보푸란의 반수치사농도(LC$_{50}$)는 2.5 ppm이었으며, 1 ppb 카보푸란에 24시간 노출된 경우, AChE 효소활성이 머리와 몸통부위에서 각각 30, 20%씩 감소되었다. 한편, MAO 효소활성은 카보푸란의 농도가 증가함에 따라 머리부위에서는 감소한 반면, 몸통부위에서는 증가하는 경향을 보였다. 특히 카보푸란의 농도가 1 ppb에서도 송사리의 MAO 효소활성이 영향을 받는 것으로 나타나, 카보푸란에 의한 송사리의 행동이상은 AChE 활성 뿐 아니라 MAO활성의 변화에 의한 복합적인 효과일 가능성이 높다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.103-108
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• 2001

Toxic effect of TBTO on larva flounder was studied by the use of a food-chain system in which indirect toxicity from seawater or/and plankton can be measured, Under the treatment of 0.5 ng/L TBTO, the combined effect of diets ( Chlorella and rotifer) and seawater was significant by synergism, although the sole effect from TBTO treated diets or seawater was equally not, The values of $LT_{50}$ from results of acute-toxicity experiments for juvenile flounder were estimated to be 230.0, 48.0, 24.0, 14.6, 9.3 5.5 3.0 and 1.7 hr at 1, 10, 25, 50, 100, 250, 500 and 1000 ng/L of TBTO, respectively, and $96hr-LC_{50}$ was 3.5 ng/L. From the above results, the experiments for chronic toxicity of TBTO was executed at the concentration range of $1\sim10 ng/L$. In long-term experiments for four months, the weight and the total length of the juvenile flounder in all TBTO treated experiments slowly increased when compared to control. No significant differences in the growth and survival of the juvenile flounder were found in the treatment of 1 ng/L TBTO(P>0.05), But, $90\%$ of the juvenile flounder died in 20 days under TBTO treated seawater at both concentrations of 5 and 10 ng/L, The TBTO treated on seawater was more effective and significantly different in the growth and survival of the juvenile flounder when compare with that on artificial diets (P<0.05). From the all results, TBTO should be regulated below 5 ng/L in a coast.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.126-136
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• 1998

For the purpose of effective control strategy of the melon aphid, Aphis gossypii and the diamondback moth, Plutella xylostella, thiamethoxam and 3 other insecticides in different classes were used with bioassay test methods in laboratory and greenhouse. They were examined to evaluated and compared with contact toxicity, stomach toxicity, rapid action, systemic action, and residual effect of imidacloprid, thiamethoxam (nicotinoids), acephate (organophosphorates), and carbosulfan (carbamates). As results of contact toxicity responses of A. gassypii against 4 insecticides using a spray application method, $LC_{50}$ values of acephate, carbosulfan, imidacloprid and thiamethoxam were 41.9, 5.2, 1.1, and 0.7 ppm. respectively. In the evaluation of stomach toxicity response of P. xylostella using a leaf-dipping method, with the 2nd instar larva $LC_{50}$ values of imidacloprid, thiamethoxam and acetamiprid were 64.9, 24.6 and 15.2 ppm, with the 3rd instar larva were 125.2, 42.7 and 27.8 ppm. and with the 4th instar larva were 241.1, 44.5 and 23.9 ppm, respectively. In the case of rapid action to A. gossypii using a spray application method after inoculation, $LT_{50}$ values of imidacloprid, thiamethoxam, carbosulfan, and acephate were 26.6, 28.0, 30.3, and 41.7 min. respectively. Otherwise, in the inoculation after applying compounds, $LT_{50}$ values of thiamethoxam, imidacloprid, and carbosulfan were 95.5, 118.0, and 122.9 min. respectively. Evaluating to systemic action from the abaxial surface to the adaxial surface of red pepper leaf with spray method, $LT_{50}$ values of thiamethoxam, imidacloprid, and carbosulfan were 162.2, 168.9, and 564.1 min. respectively. For the systemic action from the lower leaves to the upper leaves on red pepper, $LT_{50}$ values of carbosulfan, thiamethoxam, imidacloprid, and acephate were 2.3, 2.9, 3.0, and 8.8 days, respectively. In red pepper plant, $LT_{50}$ values of carbosulfan, imidacloprid, thiamethoxam, and acephate on the systemic action from the roots to the upper leaf were 0.6, 1.0, 1.0, and 13.8 days, respectively. As these results, it might be that thiamethoxam was excellent on systemic effect in red pepper. For the evaluation of residual effect on red pepper with A. gossypii, thiamethoxam and imidacloprid maintained high control effects as over 80% upto 10 days after treating compounds.

• The Korean Journal of Pesticide Science
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• v.13 no.2
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• pp.87-97
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• 2009

Octachlorostyrene (OCS) is a persistant and bioaccumulative toxic subtance (PBTs). In this study, acute toxicity tests on algae, daphnia and fish for octachlorostyrene and its isomers were done to determine effective concentration ($EC_{50}$), Lethal concentration ($LC_{50}$), no observed effect concentration (NOEC) or lowest observed effect concentration (LOEC). As a result, NOEC on algae growth inhibition test for octacholorostyrene and 2-, 3-chlorostyrene was determined as $0.50\;mg\;L^{-1}$, and NOEC for 4-chlorostyrene was determined as $0.13\;mg\;L^{-1}$. NOEC on daphnia, acute immobilisation test for octachlorostyrene and 2-, 3-chlorostyrene was determined as $5.00\;mg\;L^{-1}$ and $EC_{50}$ for 4-chlorostyrene was determined as $2.128\;mg\;L^{-1}$. NOEC on Oryzias Latipes, acute toxicity test for octachlorostyrene was determined as $80.0\;mg\;L^{-1}$ and NOEC for 2-, 3-chlorostyrene was determined as $60.0\;mg\;L^{-1}$. $LC_{50}$ for 4-chlorostyrene was determined as $39.0\;mg\;L^{-1}$ (48h) and $22.6\;mg\;L^{-1}$ (96h).

• Journal of fish pathology
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• v.22 no.1
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• pp.1-7
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• 2009

To investigate the effect of hydrogen peroxide in israel carp, Cyprinus carpio, toxicity and microbial activities were determined. For hydrogen peroxide toxicity test, the median lethal concentration ($LC_{50}$) to israel carps Cyprinus carpio (average weight 0.44 g) by acute toxicity was determined after 24 hour treatment. All israel carp were alive in 24 hours treatment at 80 $\mu\ell/\ell$ concentration and $LC_{50}$ value was 148.9 $\mu\ell/\ell$. For biocidal activities of hydrogen peroxide, remove of parasite and growth inhibition of pathogenic bacteria were determined. The parasite Trichodina sp. infected on the skin and gills of israel carps (average weight 0.1 g) was completely eliminated at 40 $\mu\ell/\ell$ of hydrogen peroxide treatment for 24 hour. Most of the minimum inhibitory concentrations (MICs) against 30 fish pathogenic bacteria were less than 40 $\mu\ell/\ell$.

• Journal of fish pathology
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• v.23 no.3
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• pp.293-302
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• 2010

Effects of formalin on removal of Pseudodactylogyrus spp. were examined against naturally infected eel, Anguilla japonica (weight 89.9~96g) at a water temperature of $28^{\circ}$. Prior to experiments for removal of the parasite, the hematological toxicity of formalin bath at 0~500 ppm for 30 min~24 h was assessed by hematocrit values (Ht). Based on the results of Ht, appropriate methods of treatment, concentrations and durations, were examined in the main study. There was no significant (P>0.05) change of Ht in 100 to 200 ppm for 24 h. In contrast, Ht increased significantly (P<0.05) at above 300 ppm. This suggests that physiological damage was caused by formalin bath treating with 300 to 500 ppm. Formalin bath with 100 and 200 ppm for 24 h caused significant decreases (P<0.05) in the infection of the parasite. In conclusion, the 100 ppm formalin for 24 hour-bath was found most recommendable for the effective treatment of Pseudodactylogyrus spp. for the gills of the infected eel because of the median lethal concentration ($LC_{50}$) of formalin to eel; cumulative mortalities were found to be 0 and 13.3%, respectively, following 24 h bathing.

• Korean journal of applied entomology
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• v.40 no.1
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• pp.69-76
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• 2001

The entomopathogenic nematodes, Steinernema carpocapsae Pocheon strain (ScP) and Heterorhabditis bacteriophora Hamyang strain (HbH) were evaluated against chestnut insect pests, The farmers＇handling methods of chestnuts were taken into consideration to develop practical biological control with entomopathogenic nematodes . The major insect pests found with chestnuts were Curculio sikkimensis, Seichocrocis punctiferalis, and Cydia kurokoi. Although individual chestnut contained one species of insect was 58% representing 18% by C. sikkimensis, 27.7% by D. punctiferalis and 12.3% by C. kurokoi. The percentage of co-infection of C. sikkimensis with D. punctiferalis was 3.3%, C. sikkimensis with C. kurokoi 5.0%, D. punctiferalis with C. kurokoi 7.7%, and C. sikkimensis with D. punctiferalis and C. kurokoi 5.0%. The entomopathogenic nematodes, ScP and HbH were effective against all the species of chestnut insect pests. The $LC_{50}$ of ScP was 14.6 for C. sikkimensis, 4.6 for D. punctiferalis, and 5.6 for C. kurokoi and that of HbH was 49.2 for C. sikkimensis, 5.8 for D. punctiferalis, and 13.9 for C. kurokoi, respectively. When ScP was applied into pot including harvested chestnuts at the rate of 4,813 infective juveniles (Ijs)/pot $(=1\times10^9/ha)$, mortality of C. sikkimensis, D. punctiferalis, and C. kurokoi was 85.3%, 96.9%, and 68.1%, respectively. The mortality of C. sikkimensis, D. punctiferalis, and C. kurokoi was 60.73%, 96.5%, and 66.8%, respectively when HbH was applied at the same rate. Combination of two nematode species produced similar effects and insects were more infected by ScP than HbH. When chestnuts were soaked in the suspension of ScP at the rate of 300, 3,000, and 30,000 Ijs for 10 minutes or 30 minutes, mortalities of all chestnut insects were high irrespective of soaking time, concentration , and nematode species.