• Journal of Marine Life Science
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• v.6 no.2
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• pp.73-79
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• 2021

Bisphenol A is a representative endocrine disruptor and continuously detected in aquatic environment due to wide use, resulting in adverse effects on growth, development, and reproduction in diverse organisms as well as human. Structural analogs have been developed to substitute BPA are also suspected to have endocrine disrupting effects. In the present study, the time-dependent expression patterns of ecdysteroid synthesis (nvd, cyp314a1), receptors (EcRA, EcRB, USP, ERR), and downstream signaling pathway - related genes (HR3, E75, Vtg, VtgR) were investigated using quantitative real time reverse transcription polymerase chain reaction (qRT-PCR) in the brackish water flea Diaphanosoma celebensis exposed to Bisphenol analogs (BPs; BPA, BPF, and BPS) for 6, 12, and 24 h. As results, the expression of nvd, cyp314a1, EcRs, USP, ERR and E75 mRNA was upregulated at 6 h exposure to BPF, which is earlier than BPA and BPS (12 h). On the other hand, HR3, E75 and VtgR mRNA levels were elevated at 6 h earlier at BPS and BPF than at BPA (12 h), but Vtg mRNA level was slightly changed within 24 h. These findings suggest that like BPA, BPF and BPS can also modulate the transcription of ecdysteroid pathway - related genes with different mechanisms, and have a potential as endocrine disruptors. This study will provide a better understanding the molecular mode of action of bisphenols on ecdysteroid pathway in the brackish water flea.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.452-462
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• 2021

Pretilachlor (PRE) is a common acetanilide herbicide used worldwide. However, its effects on aquatic organisms, particularly marine photosynthetic life, are not sufficiently known. Herein, we evaluated the toxic effects of PRE by physiological and molecular parameters in the photosynthetic dinoflagellate Prorocentrum minimum. The cell density, pigment content, and photosynthetic parameters (F_v/F_m and PI_ABS) were considerably decreased with increased PRE exposure time and doses. In addition, photosynthesis-related genes, PmpsbA, PmpsaA, and PmatpB, were significantly upregulated when exposed to 1.0 mg L^-1 of PRE for 24 h (p<0.001). In 72 h treatment, the relative gene expression was significantly increased (0.1 and 0.5 mg L^-1; p<0.01). In contrast, PmrbcL was decreased or little changed compared to the controls. Reactive oxygen species (ROS) increased after 24 h exposure (p<0.001). However, the transcriptional fold-changes in glutathione S-transferase (GST) were significantly increased (0.5 and 1.0 mg L^-1; p<0.001) at 72 h. These findings suggested that the PmGST might be involved in PRE detoxification in P. minimum. In addition, PRE may affect the photosystem function in phytoplankton similar to other acetanilides, causing severe damage or cell death.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.256-265
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• 2023

Chlorothalonil is continuously introduced into the marine environment and has significant toxic effects on various marine organisms, however, research on its effect on seaweed is limited. Therefore, we analyzed the impact of chlorothalonil on the early life stages of major aquaculture species in Korea, Undaria pinnatifida. U. pinnatifida female gametophytes were exposed to different concentrations of chlorothalonil (0, 0.03, 0.05, 0.10, 0.20, and 0.40 mg L^-1), and their survival rate and relative growth rate were analyzed. The no observed effect concentration (NOEC), lowest observed effect concentration (LOEC), and median lethal concentration (LC50) for female gametophyte survival were determined as 0.05, 0.10, and 0.141(0.121-0.166)mg L^-1. NOEC, LOEC, and median effective concentration (EC50) for relative growth rate were 0.10, 0.20, and 0.124 (0.119-0.131) mg L^-1. Therefore, female gametophytes of U. pinnatifida are expected to experience toxic effects at concentrations above 0.05-0.10 mg L^-1 of chlorothalonil. These research findings are anticipated to serve as crucial reference data for evaluating the effects of chlorothalonil on the health of U. pinnatifida in the early life stages.

• Journal of Marine Bioscience and Biotechnology
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• v.15 no.2
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• pp.82-89
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• 2023

Microalgae, as photosynthetic organisms, possess the ability to produce a diverse array of bioactive compounds. This study focused on the transformant Chlamydomonas reinhardtii dZL and subjected it to cultivation under varying light intensities (60, 120, 180, and 240 µmol/m²/s). Our aim was to assess the impact of light intensity on both microalgal biomass and carotenoid production. The cultivation took place in 80 mL bubble column photobioreactors, specifically the Multi-cultivator. Notably, the culture exposed to 240 µmol/m²/s exhibited the most rapid cell growth, surpassing even the cell concentration achieved at 180 µmol/m²/s by day 8. A detailed analysis of the specific irradiance rate over time unequivocally revealed a sharp decline in growth rates when the rate fell below 2 × 10^-10 µmol/cell/s. Although the culture with 60 µmol/m²/s yielded the highest carotenoid content (1.2% of dry weight), the culture exposed to 240 µmol/m²/s recorded the highest carotenoid concentration at 8.9 mg/L owing to its higher biomass. Our findings reveal the critical importance of maintaining a specific irradiance rate above 2 × 10^-10 µmol/cell/s to enhance biomass and carotenoid productivity. This study lays the groundwork for defining optimal light intensity conditions applicable to mass culture systems, with the objective of augmenting C. reinhardtii biomass and optimizing carotenoid productivity.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.1
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• pp.1-12
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• 2024

In this study, we analyzed the water temperature variability in the sea area of the Korean Peninsula in August, before and after the typhoon inflow through Typhoon Soulik, the 19th in 2018 that turned right around the Korean Peninsula and passed through the East Sea, and Typhoon Bavi, the eighth in 2020 that advanced north and passed through the Yellow Sea. The data used in this study included the water temperature data recorded in the real-time information system for aquaculture environment provided by the National Institute of Fisheries Science, wind data near the water as recorded by the automatic weather system, and water temperature data provided by the NOAA/AVHRR satellite. According to the analysis, when typhoons with different movement paths passed through the Korean Peninsula, the water temperature in the East Sea repeatedly upwelled (northern winds) and downwelled (southern winds) depending on the wind speed and direction. In particular, when Typhoon Soulik passed through the East sea, the water temperature dropped sharply by around 10 ℃. When Typhoon Bavi passed through the center of the Yellow Sea, the water temperature rose in certain observed areas of the Yellow Sea and even in certain areas of the South Sea. Warmer water flowed into cold water regions owing to the movement of Typhoon Bavi, causing water temperature to rise. The water temperature appeared to have recovered to normal. By understanding the water temperature variability in the sea area of the Korean Peninsula caused by typhoons, this research is expected to minimize the negative effects of abnormal climate on aquaculture organisms and contribute to the formulation of damage response strategies for fisheries disasters in sea areas.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.2
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• pp.147-155
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• 2008

A series of experiments were conducted to find standard test organisms and to develop test protocols for sediment toxicity tests using indigenous amphipods inhabited in Korean coastal environments. The indigenous amphipods Mandibulophoxus mai and Monocorophium acherusicum were well associated with various sediment substrates from sand to mud. The tolerance limits to various physico-chemical factors affecting bioassay results such as temperature, salinity and total ammonium as well as the sensitivities to contaminants in water and sediments were investigated using M. mai and M. acherusicum in the present study. These amphipods were tolerable to the adequate ranges of salinity ($10{\sim}30\;psu$), temperature ($10{\sim}25^{\circ}C$) and ammonia (<50 ppm). They have relevant sensitivities to the reference toxicants, dissolved cadmium as well as other metals and organic pollutants, when compared to the standard test species used in other countries. Field-sediment toxicity tests revealed that M. mai would be more sensitive to sediment-associated pollutants than M. acherusicum, while the sensitivity of M. acherusicum was comparable to those of other sediment test species in other countries. Overall results of this first attempt to develop an amphipod sediment toxicity test protocol in Korea indicated that M. mai and M. acherusicum should be applicable in the toxicity assessment of contaminated sediments, following the further evaluation encompassing various ecological and toxicological evaluation and the standardization of test method.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.1
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• pp.1-7
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• 2010

We were successfully reared young marine ornamental larva fish in a unique process of microalgae blooming culture tank. The marine fish larva was grown and survived in this method. Generally, we called this method as natural mixed culture. Observed planktonic microalgae were 34 species with 19 diatoms (Detonula pumila, Nitzschia sp., Fragilaria oceanica, Chaetoceros curvisetus, Stephanodiscus sp., Chaetoceros decipies, Chaetoceros sp., Thalassiosira rotula, Eucampia zodiacus, Diploneis splendica, Nitzschia longissima, Surirella cuneata, Asterionella glacialis, Nitzschia spp., Chaetoceros debile, Thalassionema nitzschioides, Nitzschia closterium, Skeletonema costatum and Licmophora sp.), 14 flagellates (Euglena, sp., Gonyaulax sp., Pyramimonas sp., Protoperidinium sp., Eutreptia sp., Parapedinella sp., unidentified micrc-flagellate, Gyrodinium sp., Scrippsiell trochoidea, Gymnodinium sanguineum, Chrysochromulina sp., Gymnodinium sp., Prorocentrum triestinum and Micromonas sp.) and 1 ciliate (Mesodinium rubrum) in this culture tank. Dominant microalgae were Chrysochromulina sp. during the larval rearing periods. Blooming condition maintained continuously and stably from 10 to 60 days in this microcosm.

• Ocean and Polar Research
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• v.35 no.2
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• pp.69-83
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• 2013

Metal concentrations in creek water, sewer outlets and core sediments were analyzed to identify the potential origin of metal pollution and to evaluate the extent of metal pollution and potential toxicity of Lake Shihwa. Mean concentrations for dissolved metals in creek water and sewer outlets were 1.6~136 times higher than those in the surface seawater of Lake Shihwa. Metal concentrations in creek water from an industrial region were also higher than those from municipal and agricultural regions, indicating that the potential source of metal pollution in the study area might be mainly due to industrial activities. The vertical profiles of metals in core sediments showed an increasing trend toward the upper sediments. Extremely higher concentrations of metals were observed in the vicinity of Banweol industrial complex. The results of a geo-accumulation index indicated that Cu, Zn and Cd were highly polluted. By comparing the sediment quality guidelines such as TEL and PEL, six metals such as Cr, Ni, Cu, Zn, Cd and Pb levels in core sediments nearby industrial complex exceeded the PEL value. Mean PEL quotient (mPELQ) was used to integrate the estimate of potential toxicity for measured metals in the present study. Mean PELQs in core sediments from Lake Shihwa ranged from 0.2~2.3, indicating that benthic organisms nearby the industrial complex may have been adversely affected.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.4
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• pp.257-266
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• 2008

PAHs are of mainly anthropogenic origin from urban runoff, oil spill and combustion of fossil fuels. Some PAHs are potentially carcinogenic and mutagenic to aquatic organisms. This study was carried out to survey the contamination of PAHs in the column sediments around Gwangyang bay. Yeosu petrochemical industrial complex, POSCO(Pohang steel compony) and Gwangyang container harbor are located near the bay. The column sediments were collected at 4 stations(A, B, C and D) and fractionated at intervals of two-centimeter depth on July 29, 1999. PAHs in colmn sediment samples were extracted in soxhlet extractor and were identified and quantified by GC-MS. PAHs compounds were analyzed and found to be 13 species. Total PAHs concentrations in the column sediments ranged from 275.04 to 2,838.64${\mu}g/kg$ dry wt. Naphthalene had the highest concentration in the range of 40.60 to 2,294.06${\mu}g/kg$ dry wt. and Anthracene had the lowest concentration in the range of 2.63 to 11.30${\mu}g/kg$ dry wt. The correlation coefficients between individual PAHs and total PAHs in the column sediments were relatively higher in the low molecular compounds such as Naphthalene, Acenaphthylene and Phenanthrene. The relationship between the P/A(Phenanthrene/Anthracene)ratio and F/P(Fluoranthene/Pyrene)ratio showed that P/A ratio was generally above 10 and F/P ratio was above 1 in all sediment samples. These data indicate that PAHs in the column sediments around Gwangyang bay seem to be of both pyrolytic and petrogenic origin The values of PAHs in the column sediments were lower than the biological effect guidelines.

• Journal of fish pathology
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• v.24 no.2
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• pp.131-139
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• 2011

Bisphenol A (BPA) is mainly used in the production of epoxy resins and polycarbonate plastics, which is a known endocrine disruptor and acutely toxic to aquatic organisms. In this study, estrogenic effect of BPA was investigated on hybrid between Oryzias dancena and O. javanicus (ODJ). ODJ were exposed to BPA of various concentrations (eg. 2.5 mg/L, 5.0 mg/L and 10.0 mg/L) for 56 days. The growth rate, abnormality and the ratio of female and male were observed in test group and control group. As a result, the growth was $14.7{\pm}2.0$ mm in total length (TL) in 2.5 mg/L, $13.7{\pm}2.5$ mm in 5.0 mg/L, $12.8{\pm}2.5$ mm in 10.0 mg/L in test group while it was $18.0{\pm}1.2$ mm in TL in control group which was not treated with bisphenol A. The result showed that the growth decreased as the concentration of BPA increased. The abnormality rate was 13.6% in control group, 65.4% in 2.5 mg/L, 81.3% in 5.0 mg/L and 98.1 % in 10.0 mg/L which showed increase in abnormality as an increase of BPA concentration. As a result of analyzing ratio of sex in the test group and control group, 6.0% was examined to be interspecific in controls, 76.9% in 2.5 mg/L and 100.0% in 5.0 mg/L and 10.0 mg/L. In conclusion, these results suggest that BPA has estrogenic effect on ODJ.