• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.6
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• pp.536-544
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• 2012

It is necessary to study the material circulation of coastal ecosystem according to aquacultural activity in order to induce the sustainable production of aquaculture and the fishery environment for the useful use. Hence, it is essential to make an exact assessment for the sedimentation release flux at the sediment-water interface in the aquafarm. Sediment oxygen demand and dissolved inorganic nitrogen release fluxes were compared using in-situ and laboratory incubational examination. Sediment oxygen demands were 116, 34, and $31\;mmol\;O_2\;m^{-2}\;d^{-1}$ (in-situ incubation), 52, 17, and $15\;mmol\;O_2\;m^{-2}\;d^{-1}$ (Core incubation) and dissolved inorganic nitrogen release fluxes were 7.18, 7.98, and $1.78\;mmol\;m^{-2}\;d^{-1}$ (in-situ incubation), 3.33, 3.74, and $1.96\;mmol\;m^{-2}\;d^{-1}$ (Core incubation) at Tongyeong finfish, Yeosu finfish, and Wando abalone cage farms, respectively. Consequently, in-situ incubation results showed two times higher than laboratory examination. We compared the material flux at the sediment-water interface of each farm and the characteristics between two different kinds of material flux examination.

• Korean Journal of Remote Sensing
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• v.28 no.5
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• pp.531-548
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• 2012

To identify Cochlodinium polykrikoides red tide from non-red tide water (satellite high chlorophyll waters) in the South Sea of Korea (SSK), we improved a spectral classification method proposed by Son et al.(2011) for the world first Geostationary Ocean Color Imager (GOCI). C. polykrikoides blooms and non-red tide waters were classified based on four different criteria. The first step revealed that the radiance peaks of potential red tide water occurred at 555 and 680 nm (fluorescence peak). The second step separated optically different waters that were influenced by relatively low and high contributions of colored dissolved organic matter (CDOM) (including detritus) to chlorophyll. The third and fourth steps discriminated red tide water from non-red tide water based on the blue-to-green ratio, respectively. After applying the red tide classification, the spectral response of C. polykrikoides red tide water, which is influenced by pigment concentration as well as CDOM (detritus), showed different slopes for the blue and green bands (lower slope at blue bands and higher slope at green bands). The opposite result was found for non-red tide water. This modified spectral classification method for GOCI led to increase user accuracy for C. polykrikoides and non-red tide blooms and provided a more reliable and robust identification of red tides over a wide range of oceanic environments than was possible using chlorophyll a concentration, or proposed red tide detection algorithms. Maps of C. polykrikoides red tide in SSK outlined patches of red tide covering the area near Naro-do and Tongyeong during the end of July and early of August, 2012 and extending into from Wan-do and Geoje-do during the middle of August, 2012.

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.240-247
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• 2015

This study was carried out to provide the preliminary data for study of zooplankton community structures and coastal pelagic ecosystem by understanding the seasonal change of zooplankton community depending on environmental factors at Dangdong bay in Tongyeong city. In this study, the environmental factors and the change of zooplankton community were analyzed for 2008 to 2011. In the results, a total of 80 species of zooplankton was sampled with a mean density of $1,599inds.m^{-3}$. The dominant species changed seasonally, and the most dominant species was Acartia steueri in winter and spring, Penilia avirostris in summer, and Evadne nordmanni in autumn. The Canonical Correspondence Analysis was conducted between the major dominant species and environmental factors. And for the environmental factors that effect the zooplankton community, the high correlation was observed with the water temperature, COD, DO and T-N, though there was slight difference among species. Therefore, more various research and environmental study are necessary to understand of planktonic ecosystem because the zooplankton community is affected by the interaction of both physical and biological factors.

• The Journal of the Petrological Society of Korea
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• v.27 no.3
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• pp.121-138
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• 2018

We have examined the petrotectonic setting and magmatic evolution from petrochemical characteristics of major and trace elements for the Cretaceous volcanic rocks in and around the Mireukdo Island. The volcanic rocks, can be devided into Jusasan, Unmunsa, Yokji and Saryang subgroups on the ascending order, are classified as basalt, basaltic andesite, andesite, dacite and rhyolite on TAS diagram. Petrochemical data show that the rocks are calc-alkaline series, and suggest that erupted earlier medium-K series and later high-K series. The volcanic rocks provide a case in which the calc-alkaline magma are formed, not only from separate protoliths, but following separate paths from source to surface. Earlier and later subgroups take different paths to the surface respectively, and are emplaced in the shallow crust as a series of discrete magma chambers through the volcanic processes. After emplacement, each chamber evolves indepently through fractional crystallization with a little assimilation of wall rock. The volcanic rocks have close petrotectonic affinities with orogenic suite and subduction-related volcanic arc. The rhyolitic magma can be derived from calc-alkaline andesitic magma by fractional crystallization with crustal assimilation, which may be derived from a partial melt of peridotite in the upper mantle.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.1
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• pp.1-7
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• 2009

The toxicity of two species of puffer fish, Takifugu poecilonotus (Heuinjeombok) and T. vermicularis (Gukmaeribok) collected from the coastal regions of Korea was determined using a mouse bioassay. In the T. poecilonotus collected in Jeju and Tongyeong, the proportion of toxic specimens containing ${\ge}10$ mouse units (MU) per gram exceeded 95% for the skin, liver, ovary, and fin, and approximately 30% for the testis and muscles. In each of the organs, the highest toxin levels were 79 MU/g in the muscle, hundreds (158-365) of MU per gram in the fin, intestine, testis, and gallbladder, but thousands (1,147-2,406) of MU per gram in the skin, liver, and ovary. In T. vermicularis collected from Incheon and Gunsan, the proportions of toxic specimens were 100% for the gallbladder, and 56-68% for the skin, fin, liver, and intestine however, no toxic muscle specimens were noted. The highest toxin scores were below 10 mouse units (MU) per gram in the muscle, 20-94 MU/g in the skin and fin, 319 MU/g in the intestine, and thousands (1,548-4,624) of MU per gram in the liver, gonad, and gallbladder. The toxicity in the muscle of T. vermicularis was deemed acceptable for human consumption, whereas the toxicities in the muscle of T. poecilonotus and the skin of both species of puffer fish were significantly high, such that special attention may be required when the fish is intended for human consumption.

• Journal of Environmental Science International
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• v.15 no.6
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• pp.539-562
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• 2006

The clarification of spatial-temporal patterns of phytoplankton from southern coastal waters during the period of March to November in 2004 was carried out. Total cell numbers were shown in 5,286 cells $ml^{-1}$ on March and reached to encounter a peak of 27,775 cells $ml^{-1}$ on July. Mean cell number was also shown in maximum of 1,587 cells $ml^{-1}$ on July, which recorded approximately two times higher than on June. The cell number of phytoplankton from southmiddle waters attained an abundance of ${\geq}35%$ regardless of months, which was the highest the abundance of phytoplankton in 2004 than any other waters in this study. Southwestern waters were lower the cell number of 2-5 times than those of southmiddle and southeastern waters. In particular, Prorocentrum occurred in southeastern waters on June and the highest cell number of 8,200 cells $ml^{-1}$ around Tongyeong region on July, which was recorded to occupy the value of 60.9% in southeast waters. The abundance of Skeletonema costatum as a dominant taxa in southwest was shown in ${\geq}60%$ on March, July, September, and October, whereas was also recorded to achieve the abundance of above 80% in southmiddle waters on March, July, and September. The majority of the taxa in southeastern waters was diatom: Eucampia zoodiacus, and Chaetoceros spp.. They occupied above 45%. On November, most of southern waters were abundant to Chaetoceros spp. On the basis of cluster analysis using SPSS ver 10.0, phytoplankton occurring on March showed somewhat no correlation with all of southern waters. In contrast to on March, the relationship between southwestern and southmiddle waters was shown on August and November, indicating a distinction from southeastern waters. However, the distance between southwestern/middle and southeastern waters appeared to be less than 5. Consequently, the abundance of phytoplankton in southern waters showed much fluctuations in temporal and spatial assays. In particular, southwestern and southmiddle waters during the periods of summer and winter appeared to be a similar to environmental characteristics.

• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.159-164
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• 2007

Pea weevil was easily observed in the flower and pod of garden pea, but not observed in soybean at various locations in Yeongnam district through 2001 to 2003. Number of pea weevil observed in pea flower was the highest at Milyang (20), followed by Yangsan (15), Sacheon (14) and Changnyong (13), and was the lowest at Pohang (3). On the other hand, number of pea weevil observed in pea pod was the highest at Tongyeong (192), followed by Changnyong (171), Sacheon (157) and Changwon (138), and was the lowest at Pohang (12) which showed simila. tendency with the result of pea flower. Number of pea weevil occurrence observed in pea pod after one and two times applications of Insecticides in pea field were different at harvest day of 30th May while were not significantly different at harvest day of 5th June. Likewise, number of pea pod damage after one and two times applications of insecticides were different at harvest day of 10th May while was not different at harvest day of 5th June. Thus, control efficacies of insecticides according to application times against pea weevil showed very high with above 95% at harvest day of 6th June while showed variable control efficacies at harvest of 30th May.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.4
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• pp.329-337
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• 2006

A small hydro-power plant operated by cooling water discharged from the power plant is under construction. In this study, the flow characteristics of the effluent channel and the outfall coastal zone in which the facilities are constructed have been measured and analysed. The flow pattern is highly dependent on the effluent discharge and clearly classified as these typical areas; the upstream and downstream areas of the weir, and the outfall coastal zone. The discharge and the width of the channel in the upstream area of the weir are increased step by step, so the water level fluctuation is small. The flow overtopping the weir is rapidly changing and has highly vertical fluctuation patterns after hydraulic jump just below the weir. The flow pattern in the outfall zone is directed toward the seaward direction and the velocity is dominated by the tidal level fluctuation. The mean tidal range in this area is about 10% greater than that of the Tongyeong tidal gauging station and the wave effects are negligible because of the sheltering effects of this area.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.234-240
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• 2013

This test was performed to evaluate the bactericidal efficacy of Fumagari OPP$^{(R)}$, fumigation disinfectant, containing 20% ortho-phenylphenol against Escherichia coli (E. coli) and Salmonella typhimurium (S. typhimurium). In preliminary tests, both E. coli and S. typhimurium working culture suspension number (N value) was $4.0{\times}10^8$ CFU/mL. And all of the colony numbers on the carriers exposed the fumigant (n1, n2, n3) were higher than 0.5N1 (the number of bacterial test suspentions by pour plate method), 0.5N2 (the number of bacterial test suspentions by filter membrane method) and 0.5N1, respectively. In addition, the mean number of bacteria recovered on the control-carriers (T value) was $3.4{\times}10^6$ CFU/mL. In the bactericidal effect of the fumigant, the reduction number of S. typhimurium and E. coli (d value) was 5.26 and 5.64 logCFU/mL, respectively. According to the French standard for the fumigant, the d value for the effective bactericidal fumigant should be over than 5 logCFU/mL. With the results of this study, Fumagari OPP$^{(R)}$ has an effective bactericidal activity, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with pathogenic bacteria.

• Journal of fish pathology
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• v.23 no.1
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• pp.27-35
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• 2010

Pathogens on the cultured 579 rockfish, Sebastes schlegeli in the marine cage farms from Geoje and Tongyeong of the Southern sea were investigated from 2006 to 2008. The pathogens were detected throughout the year at 46.0~90.0% for 3 years and the detection rate was low with an average 58.1% in May and high with an average 81.5% in October. Bacteria only, bacteria-parasite mix and virus only were found in October and November as well as parasite only, whereas infection of parasite only was dominant in May when the temperature increased and in August when the temperature peaked. Of rockfish, Microcotyle sp. and Caligus sp. were dominant for parasitic disease, and Vibrio sp. and Streptococcus sp. were dominant bacteria. For virus, RSIV and VNNV were detected as dominant organisms. While no virus was detected in 2006, VNNV, VHSV and RSIV were detected in 2007 due to $1.5\sim2.0^{\circ}C$ higher temperature than 2006 in the summer season. For total prevalence by rockfish sizes, the highest was found at 50.0~87.1% in 11~15cm sizes and 50% was found in 30 cm size. Parasite showed a similar trend of 50.0~79.6% as the total prevalence. Prevalence for bacteria varied from 1.6% (for 10 cm group) to 23.8% (for 26 cm group) and higher virus prevalence of 21.5% was found from below 25 cm group.