• YAKHAK HOEJI
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• v.37 no.5
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• pp.527-531
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• 1993

As a part of chemical study on the bioactive metabolites from marine organisms, we have investigated cytotoxicity using brine shrimp bioassay for each solvent fractions of the marine algae(12 species), marine sponges(3 species), coelenterates(2 species), echinoderms(4 species), marine molluscs(17 species), and ascidians(2 species), respectively. As the results, chloroform extract of Stichopus japonicus (LC$_{50}$ : 274 $\mu\textrm{g}$/ml), ethyl acetate extract of Anthocidaris crassispina(LC$_{50}$ : 121 $\mu\textrm{g}$/ml), n-butanol extract of Unda), ia Pinnatifida (LC$_{50}$ : 178 $\mu\textrm{g}$/ml), and water extract of Thais clavigera (LC$_{50}$ : 61 $\mu\textrm{g}$/ml) displayed the most significant cytotoxic activity against brine shrimp. Among the marine organisms tested, echinoderms and marine molluscs were thought to be the most active Phylums on screening of new bioactive compounds.

• The Korean Journal of Malacology
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• v.21 no.1
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• pp.25-31
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• 2005

The embryos of marine bivalves have been commonly used in bioassays for the quality assessment of marine environments. Although several standard protocols for developmental bioassay with bivalves have been already proposed, there have been few trials for applying these protocols in environmental assessment, or for developing new protocol with Korean species. So, there is a strong need to establish the standard bioassay protocols using bivalves commonly found in Korean waters. Prior to developing a new protocol, it is essential to know the optimum conditions for the reliable bioassay procedures. Here, we established the purpose of this study to determine the optimum bioassay conditions for successful development of a common mussel, Mytilus galloprovincialis. The conditions considered as critical for developmental bioassay, and determined in this study were; (1) temperature, (2) salinity, and (3) initial density of embryo. The optimal temperature for developmental bioassay of M. galloprovincialis was determined as $15^{\circ}C$. At this temperature, the required time for the embryo to become veliger larva was 48 hr. The acceptable range of salinity for the embryotoxicity test using M. galloprivincialis was from 30 to 35 psu, which was narrower than that of the natural habitat of adult populations. The optimum density of embryo at the beginning of bioassay was 100 embryos/ml. Over this density, the proportion of normally developed larvae decreased significantly. The results obtained in this study will serve as a basis for preparation of the standard bioassay protocol using embryo of M. galloprovincialis.

• The Korean Journal of Malacology
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• v.22 no.2
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• pp.167-173
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• 2006

The embryos of marine bivalves have been commonly used in bioassays for quality assessments of marine environments. Although several standard protocols for the developmental bioassay of bivalves have been proposed, only a few trials for application of these protocols in environmental assessments or for the development of a new protocol with Korean species have been conducted. As such, there is a strong need to establish standard bioassay protocols with bivalves commonly found in Korean waters. To determine the sensitivity of Mytilus galloprovincialis to establish a standard bioassay, their fertilized eggs were exposed to six metals (Ag, Cd, Cr, Cu, Ni, and Zn). The order of biological impact was Ag > Cu > Ni > Zn > Cr > Cd and their lowest observed effective concentration were 5, 16.4, 25.4, 142, 187 and 1,500${\mu}g/l$, respectively. The proportion of normal larvae appeared to decrease linearly with the logarithm of each toxicant concentration within the tested range. The average values of median effective concentrations $(EC_{50})$ from the triplicate experiments for Ag, Cd, Cr, Cu, Ni, and Zn were 6.8, 1,797, 786, 16.6, 68.1, and 139.2${\mu}g/l$, respectively. There was a more than 100-fold difference in $EC_{50}$ values of Cu and Cd. The value of $EC_{50}$ or median lethal concentration of Cu was within the range observed for other bivalve developmental bioassays. The overall sensitivity of M. galloprovincialis in the present developmental bioassay was also similar to that of other marine organisms commonly used in aquatic bioassays (e.g. sea urchins, oysters). Hence, the bioassay using the embryo of M. galloprovincialis is considered to be a useful tool to monitor and evaluate the quality of marine aquatic environments.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.158-158
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• 2003

Bioassays using gametes of sea urchins are widely used in ecotoxicological assessments of marine environments. Since most of sea urchin species in Korean coastal water spawn from spring to autumn, bioassay with them during the winter is impossible. In the course of developing standard methods for bioassays with Korean species, we found a winter-spawning starfish, Asterias amurensis, Since reproductive mode of asteroids is similar to echinoids, the bioassay protocol for sea urchins could be applied similarly to the starfish. Here, we tested and determined several conditions for the acceptability of bioassay with A. amurensis. The least required time for formation of fertilization membrane of fertilized eggs to be easily distinguished from unfertilized ones was 60 min. The threshold of sperm to egg ratio that could make acceptable fertilization rates in controls was 3000. The allowed time for manipulation of sperm after dilution in seawater was at most 3 hr. The optimal exposure time of sperms when the response against toxicant solution was relatively stable was in the range of 20-60 min. The tolerance range of sperms to the salinity of test solution was 26-38 psu. The sensitivity of A. amurensis sperm was intermediate among marine organisms commonly used in aquatic toxicity tests. The sperm bioassay with A. amurensis can be satisfactorily applied to toxicity assessments of marine environments.

• Environmental Analysis Health and Toxicology
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• v.25 no.1
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• pp.19-26
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• 2010

Discharged materials from the point or non-point source are released into the sea, and as the results, marine environment is directly affected. We must estimate the impacts of contaminants to marine pollution rapidly and accurately. Therefore, it is needed on early warning system for appreciating marine environmental impacts, and required a bioassay to evaluate abnormal changes. A bioassay test was developed to examine the effects of heavy metal contaminants on the early life stages of the marine annimals. We have studied the effects of metals on early development of a sea urchin species, Strongylocentrotus intermedius. S. intermedius embryos were tested with six metals (Cu, Ag, Zn, Cd, Cr, Ni) and showed the highest sensitivity to Cu as well as the lowest sensitivity to Cd. The order of biological impact for metals was Cu>Ag>Ni>Zn>Cr>Cd. In accordance with the results, sea urchins embryos can provide biological criteria for seawater quality assessment. The sensitivity of developmental bioassay whith S. intermedius is at intermediate level among marine organisms commonly used in aquatic bioassays. And this sea urchin can be routinely employed as a test organism for ecotoxicity assays.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.2 s.25
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• pp.99-106
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• 2006

The fate of chemical pollutants in the aquatic environment is generally considered to be strongly influenced by environmental factors such as pH, salinity and electrostatic charges on the surface of particles ai well as by the characteristic of chemicals. Oxolinic acid was measured by chemical analysis using HPLC to determine the effect of salinity, pH and suspended solids on chemical binding and by bioassay for measuring bioactivity. The higher contentration of suspended solids in the medium, the lower concentration of oxolinic and was detected in measurements from by both HPLC and biosssay analysis. This indicates particle may have a stronger binding or absorption effect on oxolinic acid. Bioassay analysis showed weaker bioacivity at higher salinity and pH 7.0, but this result of bioassay analysis was different from the result of HPLC.

• The Korean Journal of Malacology
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• v.30 no.3
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• pp.177-187
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• 2014

Mussels have been commonly used in bioassay for quality assessments of environment. Moreover, several standard protocols for the developmental bioassay of bivalves have been proposed. In this study, the EC50 of polycyclic aromatic hydrocarbons (PAHs) was determined using mussel, Mytilus galloprovincialis embryonic developmental bioassay. To determine the sensitivity of M. galloprovincialis, their fertilized eggs were exposed to five PAHs (2-metylnaphthalene, fluorene, dibenzothiophene, phenanthrene, pyrene). The EC50 of 2-metylnaphthalene, fluorene, dibenzothiophene, phenanthrene, and pyrene were 232, 273, 67.9, 43.2, and $33.1{\mu}g/L$, respectively. The overall sensitivity of M. galloprovincialis in the present developmental bioassay was similar to or more sensitive than that of other marine organisms commonly used in aquatic bioassays. The results of this study could be provide with fundamental data of setting standard for protection of marine life and or can use prediction the aquatic toxicity of PAHs.

• Journal of Environmental Science International
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• v.14 no.11
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• pp.1071-1079
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• 2005

Using single cell gel electrophoresis, DNA single strand breaks were determined in various marine organisms. DNA damage on fish blood cells was detected to know whether there was a difference between Incheon, Pohang, Masan, and Tongyeong as a control site. Tongyeong showed the lowest DNA damage among the study areas. Mussels, transplanted to Masan Bay for one month, revealed high DNA damage at sites with high economical activity. In two weeks exposure of polychaete to Incheon sediments, higher DNA damage was detected in the sediment adjacent to Incheon harbor than open sea. These results suggested that the marine organism from the polluted area revealed a relatively high DNA damage. In addition, these areas might be contaminated with genotoxic compounds and comet assay was useful as a bioassay to detect DNA damage in marine organisms.

• Journal of Life Science
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• v.9 no.6
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• pp.653-658
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• 1999

A novel marine microorganism, Vibrio sp. YE-101, was isolated from pufferfish and investigated for its ability to synthesize tetrodotoxin (TTX). Various strains isolated from the intestine of pufferfish were grown on TCBS agar plate, and then cultured on Ocean Research Institute (ORI) medium supplemented with 3% NaCl at 23$^{\circ}C$ for 3days. The cells were harvested, disrupted, fractionated by Bio-Gel P-2 column chromatography and then TTX-producing strain, Vibrio sp. YE-101, was identified using mouse bioassay. The isolated TTX from Vibrio sp. YE-101 was also analyzed and identified by HPLC and gas chromatography-mass spectrometer (GC-MS). The mass fragmentation of trimethylsilyl derivatives of C9-base of TTX from Vibrio sp. YE-101 was interpreted and the pattern of fragmentation was same with that of authentic standard. The purfied TTX was also positive to the mouse bioassay, which clearly represents that Vibrio sp. YE-101 can synthesize TTX.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.459-468
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• 2022

Long-term data analyses and bioassay experiments were conducted to assess limiting nutrients in Cheonsu Bay and Taean sea. First, long-term nutrient data (2004-2016) provided by the National Water Quality Monitoring Network were used to assess potential limiting nutrients. Analysis of the long-term data showed that the dissolved inorganic nitrogen/dissolved inorganic phosphate (DIN/DIP) ratio was mostly below 16, with N limitation being dominant. A subsequent analysis using the concentration ratios of N, P, and Si showed that N limitation was dominant during summer and autumn but that Si limitation occasionally occurred during winter and spring in relatively limited areas. However, the dominant limiting nutrient was not determined. The nutrient analysis of the field water collected during the bioassay experiment showed that DIN/DIP revealed P limitation at all stations in March and May, whereas N limitation was dominant in July and October. In the analysis using the concentration ratios of N, P, and Si, P and Si limitation appeared in March and May, but there were points with no dominant limiting nutrient. However, N limitation was dominant in July and October. In the bioassay experiment for assessment of the actual limiting nutrient, the results showed no specific limiting nutrient in March, whereas NH₄⁺ and NO₃^- showed responses in May, July, and October, which confirmed that N was a substantial limiting nutrient directly involved in phytoplankton growth during this period.