• Title/Summary/Keyword: Population Growth$LC_{50}$$EC_{50}$

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Development of Ecotoxicological Standard Methods using Early Life Stage of Marine Rotifer Brachionus plicatilis and Benthic Copepod Tigriopus japonicus (윤충류 Brachionus plicatilis 및 저서 요각류 Tigriopus japonicus의 초기 생활사를 이용한 해양생태독성시험 방법에 관한 연구)

  • Lee, Seung-Min;Park, Gyung-Soo;Yoon, Sung-Jin;Kang, Young-Shil;Oh, Jeong-Hwang
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.13 no.2
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    • pp.129-139
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    • 2008
  • Marine ecotoxicological standard method was applicated using marine rotifer and benthic copepod as primary consumer of marine ecosystem. Marine rotifer, Brachionus plicatilis and benthic copepod, Tigriopus japonicus were designated as standard test species with the endpoints of 24hr neonate mortality (24hr $LC_{50}$) and 48hr population growth (48hr $EC_{50}$) for rotifer, and 48hr nauplius mortality (48hr $LC_{50}$) for benthic copepod. Tests method was referred to those of ASTM (American Society for Testing and Materials) with the replacement of test species which are widely distributed in Korean waters. The two species showed a wide tolerance on salinity ($5{\sim}35\;psu$) and can be easily cultured in small space even they were not as sensitive as in the mortality test using the nauplius of marine invertebrates. However, these species revealed the significant "concentrationresponse relationship" tested with ocean disposal wastes, and reproducibility using cadmium as standard reference material between laboratories. Accordingly, these two species have good potential as test species for marine ecotoxicological test species. Also, we strongly recommend that at least one of these species be included in the test species of "battery test" in marine bioassay.

Application of the Ecotoxicological Standard Method using Population Growth Inhibition of Marine Phytoplankton (식물플랑크톤의 개체군성장저해율을 이용한 해양생태독성 시험방법에 관한 연구)

  • Lee, Sung-Min;Park, Gyung-Soo;An, Kyoung-Ho;Park, Soung-Yun;Lee, Sang-Hee
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.13 no.2
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    • pp.112-120
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    • 2008
  • A series of experiments were conducted to establish a marine ecotoxicological standard method using marine primary producers, Skeletonema costatum, Heterosigma akashiwo, Prorocentrum micans, Isochrysis galbana, Tetraselmis suecica as candidate test species. Marine diatom, S. costatum was selected as standard test species in terms of the ecological roles and international uses as test species. Test methods and test acceptability criteria are as follows; $72{\sim}96$ hr population growth inhibition $EC_{50}$ as endpoint. Static non-renewal method, and population growth rates over 0.04/hr in control as test acceptability criterium. S. costatum is widely distributed in the world ocean and used for standard species of marine toxicity test method by ISO (International Standardization Organization). Possible salinity ranges for this test method are $20{\sim}35\;psu$, and reproducibility and interlaboratory test results were consistent through the calibration tests. Sensitivity of the test method was comparable or better than other toxicity tests such as rotifer neonate mortality, bioluminescent bacterial inhibition, seaweed sporulation and sea urchin fertilization tests.

Excess zinc uptake in Paronychiurus kimi(Collembola) induces toxic effects at the individual and population levels

  • Son, Jino;Lee, Yun-Sik;Kim, Yongeun;Wee, June;Ko, Euna;Cho, Kijong
    • Korean Journal of Environmental Biology
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    • v.37 no.3
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    • pp.335-342
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    • 2019
  • The purpose of this study was to investigate the toxic effects of zinc in collembolan Paronychiurus kimi at the individual (survival and juvenile production) and population (population growth and age structure) levels after 28 days of exposure in artificially spiked soil. These toxic effects were interpreted in conjunction with the internal zinc concentrations in P. kimi. The EC50 value for juvenile production based on the total zinc concentration was 457 mg Zn kg-1 dry soil, while the LC50 value for adult survival and ri=0 value for population growth were within the same order of magnitude (2,623 and 1,637 mg Zn kg-1 dry soil, respectively). Significant differences in adult survival, juvenile production, and population growth compared with the control group were found at concentrations of 1,500, 375, and 375 mg Zn kg-1 dry or higher, respectively, whereas significant differences in the age structure, determined by the proportion of each age group in the population, were observed in all treatment groups. It appeared that the internal zinc level in P. kimi was regulated to some extent at soil zinc concentrations of ≤375 mg Zn kg-1 dry soil, but not at high soil zinc concentrations. These results indicate that, despite zinc being regulated by P. kimi, excess zinc exceeding the regulatory capacity of P. kimi can trigger changes in the responses at the individual and population levels. Given that population dynamics are affected not only by individual level but also by population level endpoints, it is concluded that the toxic effects of pollutants should be assessed at various levels.

Marine Ecotoxicological Evaluation on HNS Spill Accident : Nitric Acid Spill Case Study (HNS 유출사고가 해양생물에 미치는 생물독성 영향평가 : HNO3 유출사고 대상)

  • Kim, Tae-Won;Kim, Young Ryun;Jo, So Eun;Son, Min Ho;Lee, Moonjin;Oh, Sangwoo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.21 no.6
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    • pp.655-661
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    • 2015
  • This study intends to evaluate the effect of nitric acid($HNO_3$) spill accidents on the marine ecosystem, while $HNO_3$ is known as one of the typical HNS. For this purpose, we performed (1) the growth inhibition test by using phytoplankton(Skeletonema costatum), (2) acute and chronic toxicity test by using invertebrate(Brachionus plicatilis and Monocorphium acherusicum), (3) fish(Cyprinodon variegatus) and (4) bacteria(Vibrio fischeri). In these tests, we observed the (1) pH changes induced by the nitric acid spill and (2) changes in nitrate($NO_3$) concentration disassociated from nitric acid after the accident, respectively. The toxicity test result on pH changes induced by $HNO_3$ shows that the no observed effect concentration(NOEC), lowest observed effect concentration(LOEC) and 50 % effect concentration($72h-EC_{50}$) values of M. acherusicum are pH 7 (0.3 mM), pH 5(1.1 mM) and pH 5.2(1.4 mM), respectively, indicating that M. acherusicum is the most sensitive species. The chronic toxicity test (population growth rate test) on $NO_3{^-}$ of B. plicatilis show that the NOEC, LOEC and $96h-EC_{50}$ are 5.9 mM, 11.8 mM and 32.6 mM, respectively, indicating that B. plicatilis is the most sensitive species. In conclusion, toxic effecst on the marine organism caused by the nitric acid spill accident is determined to be so slightly except for the most adjacent area of the ship in pH scale and such concentration of nitrate, to the extent of directly influencing the survival and reproduction of the marine organism, is determined practically not to be applicable in the typical accidents in the sea.