• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.5
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• pp.514-522
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• 2020

To understand the ecotoxicological differences between representative Skeletonema sp. and Dunaliella tertiolecta, both producers as international standard test species for marine ecotoxicity testing, we compared each standard test method, and comparatively analyzed the suitability of the species for environmental assessment and their sensitivity to various test substances. Although most of the test conditions were the same in each method, there were differences in limitation of pH changing and the initial inoculation density in the validation criteria, which is supposed to originate from the low growth rate of D. tertiolecta. In terms of suitability, both species showed consistency in test performance by repeatedly meeting the validation criteria required by the standard test methods. The salinity ranges available for testing were 20 and 10 psu for Skeletonema sp. and D. tertioelecta, respectively. Finally, regarding sensitivity, the toxicity sensitivity of Skeletonema sp. was relatively higher than that of D. tertiolecta for the reference toxicant, actual polluted water discharged (ballast water), and other chemicals. This implies that using at least two species of microalgae from different classification groups could help increase the reliability and objectivity of test results in the performance of marine ecotoxicity tests using producers.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.3
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• pp.140-147
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• 2005

We investigated the interactions between coastal waters of the Yeongil Bay, Korea, and oceanic waters of the Eastern Sea, as wet 1 as the development mechanism of vertical circulation currents in the bay. The oceanic waters of the bay have an average water temperature of $12.2{\sim}18.4^{\circ}C$ and salinity of $33.32{\sim}34.43$ PSU. Results of spectral analysis have shown that the period of revolution between oceanic and coastal waters is about 0.84-0.91 years in the surface waters and 1.84 years in the bottom layer. The wind direction in the bay shifts between SW and NE, with the main wind direction being SW during the winter period, and water mass movement is influenced by such seasonal variations in wind direction. Vertical circulation currents in the bay are structured by two phenomena: the surface riverine outflow layer from the Hyeong-san River into the open sea and the bottom oceanic inflow layer with high-temperature and salinity into the bay. These phenomena start the spring when the water mass is stable and become stronger in the summer when the surface cold water develops over a 10-day period. Consequently, tidal currents have little influence in the bay; rather, these vertical and horizontal circulation currents play an important role in the transport of the pollutant load from the inner bay to the open sea.

• Korean Journal of Ichthyology
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• v.22 no.4
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• pp.256-266
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• 2010

The distribution characteristics of the eggs and larvae of anchovy Engraulis japonica, and environmental factors in the southern coastal waters of Korea were investigated from May to August 2009. Eggs and larvae were mainly distributed in the waters off Naro Island, Namhae Island and Saryang Island. High densities of eggs and larvae in temperatures of $19.0{\sim}24.0^{\circ}C$, salinites of 33.0~34.4 psu, DO of 6.05~8.13 mg/L and chlorophyll-a $1.2{\sim}2.3{\mu}g/L$ were observed. Water temperature in the coastal region was higher than that in the open sea, while salinity was lower. Evidence of sea water intrusion toward Sori Island and Maemul Island, and an inner-water intrusion from Yeoja Bay, Gamak Bay and Gwangyang Bay were observed. High densities of eggs in early developmental stage occurred in waters off Naro Island, Dolsan Island and Namhae Island, but high densities of eggs in a later developmental stage occurred in waters off Yokji Island and Maemul Island. During the survey period, the proportion of later developmental-stage eggs was higher in the eastern part of the study area.

• Journal of Genetic Medicine
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• v.5 no.1
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• pp.61-64
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• 2008

A 24-year-old female with primary amenorrhea was referred for a chromosome study. The karyotype of the patient was 46,X,der(X) under initial GTG-banding analysis. Fluorescence in situ hybridization (FISH) analysis with an LSI Kallmann (KAL) region probe [probes for Xp22.3(KAL) and CEP(X) for control] was carried out. The abnormal chromosome was KAL- and CEP(X)${\times}2$. In addition, interphase FISH analysis revealed the patient to be mosaic for two different cell lines: 90% of cells had three signals and 10% of the cells had only one signal for CEP(X). Based on these results, the karyotype of the patient was 45,X/46,X,psu idic(X)(p22.1), which is partial trisomy for Xqter${\rightarrow}$Xp22.1 and partial monosomy for Xpter${\rightarrow}$Xp22.1. This karyotype was considered a variant of Turner syndrome. In summary, Idic(X) and low-level mosaicism was successfully characterized by FISH analysis with a CEP(X) probe.

• ALGAE
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• v.21 no.1
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• pp.141-148
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• 2006

Benthic diatoms are known as a good food for shellfish in nature and in commercial hatchery of Jeju Island, Korea. Grammatophora marina is commonly found as dominant benthic micro-algae in Jeju coastal waters throughout the year. To know the best growth conditions of this species, culture was done in terms of three parameters; water temperature, salinity and nutrients. Each parameter was controlled by temperature of 15, 20 and 25°C; salinity of 25, 30 and 35 psu; and nutrient concentrations of 50, 100 and 200%. F/2 media was used with artificial seawater for the culture, which was continued for two weeks with L:D cycle 12:12 by using fluorescent light. Maximum specific growth rate was recorded 1.68 d–1 at temperature of 25°C with salinity of 35 psu and nutrient concentration of 200% on 6th day during the culture period. Maximum biomass was also observed 4.9 × 105 cells mL–1 in the same condition. This species may belong to the euryhaline and eutrophic habitat with warm condition. For nutritional aspects of this species, protein, lipid and carbohydrate were measured. The value of protein, lipid and carbohydrate was 4.96%, 15.82% and 5.65%, respectively. The antioxidant activities of 80% methanolic extract were 46.7%, 23.7% and 23.8% on DPPH (1,1-Diphenyl-2-picrylydrazy) radical, superoxide anion radical and hydrogen peroxide scavenging, respectively. Percentage metal chelating activity was 81.2%. Enzymatic extracts of Alcalase and Ultraflow showed remarkable scavenging activities on DPPH radical (86.5% and 57.2%, respectively), and superoxide anion scavenging activities were 45.3% and 41.4% from Kojizyme and Viscozyme extracts, respectively. Extract of Protomex revealed 24.8% activity on hydrogen peroxide and Neutase showed 30.8% on hydroxyl radical scavenging effects. Celluclast and Viscozyme extracts showed 33.2% and 32.1% activities on nitric oxide scavenging, respectively, while Alcalase showed 61.5% on metal chelating. This species contains higher lipids among the biochemical compounds and higher metal chelating activities from both 80% methanolic and enzymatic extracts.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.117-124
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• 1997

Vertical profiles of dissolved Cu and Ni at the upper 400 m water layer have been determined at two stations in the central East Sea in October 1995. This is the first report on the vertical distribution of trace metals in Korea. Copper concentrations are in the range of 2.1~5.8 nmol/kg and 1.6~2.4 nmol/kg for stations S and N, respectively. The vertical profile of Cu at S is found a scavenging type (i.e., drastic decrease with increasing depth). Concentrations of Ni range from 4.3 to 7.1 nmol/kg and from 3.4 to 5.4 nmol/kg for stations Sand N, respectively. At station S, Ni is best correlated with phosphate, but not at stations N. Such difference between two stations are probably due to their different vertical distribution of water masses. Station S has a strongly stratified water column with 6 distinct water masses, but station N with a well-mixed subsurface water layer extending from 50 to 300 m depth. Extremely low salinity (31.87~31.96 psu) found at the surface water of station S was interpreted as a result of the Yangtze River effluents which were probably fed into the East Sea through the Korea Strait during the late summer. Such seasonal appearance of low salinity in southern part of the East Sea was reported previously. The concentrations of Cu and Ni at two sites are comparable to those reported in the North Pacific. It was found that Ni mostly exist as dissolved phase.

• The Korean Journal of Malacology
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• v.24 no.2
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• pp.137-142
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• 2008

Growth and survival rates dependent on the density of a pen sell, Atrina pectinata were measured from Duekryang bay in Korea. Annual water temperature and salinity of the study area were ranged from 14.5 to $28.0^{\circ}C$ and from 27.98 to 31.89 psu, respectively. The pH, DO, COD, DIN, Chl-a and SPM in the study area ranged from 7.78-8.35 mg/L, 7.07-7.90 mg/L, 1.20-1.70 mg/L, 2.88-6.02 mg/L, 0.20-0.79 mg/L and 10.8-21.4 mg/L. The IL, COD and AVS in sediments ranged from 4.0-4.6%, 7.28-10.76 mg/L and 0.03-0.05 mg/L respectively. The daily growth rate of shell height and total weight were 0.27%, 0.33%(5 indiv./$m^2$), 0.26, 0.29%(10 indiv./$m^2$) and 0.21, 0.20%(35 indiv./$m^2$). The survival rate also decreased along the density gradient; highest at the lowest density of 5 indiv./$m^2$ and lowest at the maximum density of 35 indiv./$m^2$.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.190-194
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• 2011

Potassium (K) is one of the essential nutrients for plants but is not a constituent of any plant compound. K is substances for activation of many enzymes and influences the process that the enzymes are involved in catalyzing. Although experimental results associated with the K effects with both benefits and no effects on turfgrass growth were reported, the limited research results of K effects on turfgrass among K sources are available in Korea. The objectives of the study was conducted to evaluate responses of Kentucky bluegrass (Poa pratensis L.) treated by fertilizer treatments with six K sources. There were six fertilizer treatments as K sources applied to Kentucky bluegrass which were potassium nitrate (13-0-44, PN), potassium chloride (0-0-60, PC), potassium sulfate (0-0-50, PS), polymer-coated potassium sulfate (0-0-45, PPS), potassium thiosulfate (0-0-25, PT), and potassium sulfate granulated with methylene urea (20-0-25, PSU). Potassium of $8g\;m^{-2}$ and N of $5g\;m^{-2}$ was applied 4 times giving a total 20 and $30g\;m^{-2}$, respectively. Although significant differences were found for turfgrass color, quality, chlorophyll index, and clipping dry weight, no consistent results among K sources were found during the one year study. Overall, K treatments didn't affect turfgrass growth in this study.

• Korean Journal of Ichthyology
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• v.24 no.1
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• pp.11-19
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• 2012

Seasonal fish species composition in the sandy shore adjacent to eelgrass bed was determined. Monthly samples were collected by a beam trawl from August 2009 to July 2010. A total of 38 species, 1,232 individuals and 5,277.7g of fishes were collected. The dominant species were $Favonigobius$ $gymnauchen$, $Takifugu$ $niphobles$, $Hypodytes$ $rubripinnis$, and $Rudarius$ $ercodes$. These four dominant fish accounted for 73.2% of the total number of individuals, and 53.9% of the biomass of collected fish. During the survey, the water temperature ranged from 11 to $25^{\circ}C$, and the salinity ranged from 29 to 35 psu. The monthly species diversity index showed the lowest value of 0.89 in March and highest value of 2.35 in June 2010. Fish species composition and abundance in Myeongsa sandy shore, were similar to that the adjacent eelgrass bed, but were different from those of Gujora sandy shore open the sea.

• Applied Chemistry for Engineering
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• v.28 no.2
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• pp.153-157
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• 2017

Gel type internal electrolytes were synthesized by varying hydroxyethyl-cellulose (HEC) amounts and their durability and conductivity were measured. The ionic conductivity decreased as the content of HEC increased thus the internal electrolyte containing more than 12% of HEC could not be used as a reference electrode. Based on durability test results, as the HEC amount decreased carrier density resulting in increasing of the amount of KCl coming out of the porous membrane. Therefore in order to use long time at ballast water treatment systems, we selected 10% HEC for gel type internal electrolyte. The resolution test for total residual oxidants (TRO) was carried out using the TRO sensor and the gel type reference electrode made of 10% HEC. A 50 mV potential was applied to the TRO sensor for 30 sec and changes in the current were measured. It was confirmed that the TRO concentrations ranging from 0 to 15 mg/L could be separated at salinity conditions of 0.2~30 PSU. The results indicated that the TRO concentration at sea water and at fresh water was successfully measured by the TRO sensor constructed with the reference electrode using gel-type internal electrolyte of HEC.