• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.3
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• pp.241-248
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• 2002

The combined hydroacoustic and demersal trawl surveys to investigate the distribution characteristics of fish schools in the Yellow Sea and the East China Sea were carried out during the spring of 1997 by the training ship "Nagasaki Maru" of Nagasaki University. Fish samples were collected by bottom trawling from 9 trawl stations randomly selected in the survey area, and the species and length compositions of trawl catches are examined. Hydroacoustic data were collected by using a Furuno FQ-50 scientific echo sounder operating at 50KHz and the data stored in field were later processed in the laboratory. The results obtained can be summarized as follows ：1. In the 9 trawl surveys conducted in the Yellow Sea and the East China Sea, 78 species including 80 species of fishes, 4 species of Cephalopoda and 6 species of Crustacea, were identified. The most abundant species in these stations were swimming crab(Portunus trituberculatus), Japanese horse mackere(Trachurus japonicus), redlip croaker(Larimichthys polyactis) and the catch per one hour in each station ranged 7.7 to 182.5 kg/hour. 2. The mean volume backscattering strength for the entire water column and the bottom layer of the 0-10 m from bottom friction were -74.6 ㏈ and -68.2 ㏈, respectively. That is, the mean volume backscattering strength for the bottom layer was 6.4 ㏈ higher than that for the entire water column 3. In the surveys during the spring of 1997, the geographical distribution characteristics of fish schools suggests a trend of decreasing fish abundance toward the coast area of Korea and the highest demersal concentrations appeared in waters between the Cheju Island and the Tsushima Island 4. The distribution density of fish school in the East China Sea and Yellow Sea during the 1997 acoustic survey were estimated to be 6.65$\times$10$^{-5}$ kg/㎥ in the entire water column and 2.86$\times$l0$^{-4}$ kg/㎥ in the bottom layer, respectively.pectively.

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.269-276
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• 2010

Total mercury and methylmercury concentrations were determined in 15 commonly consumed aquatic food species using total mercury analyzer and gas chromatography with electron capture detector. The mean total mercury and methylmercury concentrations (mg/kg) were 0.088 and 0.034 in mackerel, 0.061 and 0.016 in hair tail, 0.030 and 0.005 in yellow croaker, 0.032 and 0.008 in Alaska pollock, 0.059 and 0.023 in eastern catfish, 0.110 and 0.045 in snakehead, 0.030 and 0.011 in Japanese common squid, 0.026 and 0.009 in common octopus, 0.035 and 0.008 in swimming crab, 0.009 and not detected (ND) in oyster, 0.011 and ND in shortneck clam, 0.008 and ND in mussel, 0.018 and ND in sea mustard, 0.007 and ND in nori, and 0.019 and ND in sea tangle, respectively. The total weekly dietary intakes of total mercury and methylmercury were estimated, respectively, using food consumption data from diet surveys and the concentrations of total mercury and methylmercury from this study. They were $0.178\;{\mu}g/kg$ body weight (b.w.)/week (3.57% of provisional tolerable weekly intake (PTWI)) and $0.052\;{\mu}g/kg$ b.w./week (3.34% of PTWI) respectively, and all were within their respective PTWI set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Therefore, considering that the main contributor to mercury intake in the diet is aquatic foods and that the 15 aquatic food species examined in this study are highly consumed, it is concluded that the mercury levels in the foods measured in this study do not present a concern for consumer health.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.465-472
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• 2001

The effects of water level reduction in rearing tank and fish transference during fish selection process on the stress response (hematological factors, cortisol, glucose, lactic acid and osmolality) of tank-reared olive flounder Paralichthys olivaceus of large (FL), small (FS) and Japanese croaker, Nibea japonica (JC) were examined in running seawater culture system. The water level of rearing unit was lowered from 33 cm to 8 cm in the course of 2 minutes in the water level reduction experiment. The fish were removed from rearing tank (12 ton) to 450 L tank in 30 seconds after capture in the fish transference experiment, In water level reduction, the hematocrit of FL was significantly increased from $14.6\%$ at beginning to $23.5\%$ after 10 hours, However, it decreased to the value of beginning after 46 hours. Plasma cortisol concentration of FL was the highest concentration (13.7 ng/mL) after 22 hours, but it decreased to 4.0 ng/mL at the end of experiment. Cortisol concentration of FS did not show any significant difference during the experiment. The cortisol concentration of JC were significantly higher at 4 hours (282.3 ng/mL) and 22 hours (350.5 ng/mL), Glucose concentration of JC was the highest (138.0 mg/dL) at 22 hours. Lactic acid concentration was not different between experimental groups. In the fish transference experiment, red blood cell of FL was increased from $1.9\times10^6\;cell/{\mu}\;L\;to\;4.2\times10^6\;cell/{\mu}L$ in 24 hours. Blood hemoglobin of JC were significantly elevated in 24 hours. At 1 hour after transference, plasma cortisol concentrations in both fish species were increased to 95.3 ng/mL in FL and 175.5 ng/mL in JC. Glucose concentration of JC was increased to 132.5 mg/dL at 1 hour, 129.5 mg/dL at 3 hours after transference.

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.347-355
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• 2014

In this study, the detection method was developed using molecular biological technique to distinguish authenticity of animal raw materials. The genes for distinction of species about animals targeted at Cytochrome c oxidase subunit I (COI), Cytochrome b (Cytb), and 16S ribosomal RNA (16S rRNA) genes in mitochondrial DNA. The species-specific primers were designed by that Polymerase Chain Reaction (PCR) product size was around 200 bp for applying to processed products. The target 24 raw materials were 2 species of domestic animals, 6 species of poultry, 2 species of freshwater fishes, 13 species of marine fishes and 1 species of crustaceans. The results of PCR for Rabbit, Fox, Pheasant, Domestic Pigeon, Rufous Turtle Dove, Quail, Tree Sparrow, Barn Swallow, Catfish, Mandarin Fish, Flying Fish, Mallotus villosus, Pacific Herring, Sand Lance, Japanese Anchovy, Small Yellow Croaker, Halibut, Jacopever, Skate Ray, Ray, File Fish, Sea Bass, Sea Urchin, and Lobster raw materials were confirmed 113 bp ~ 218 bp, respectively. Also, non-specific PCR products were not detected in compare species by species-specific primers. The method using primers developed in this study may be applied to distinguish an authenticity of food materials included animal raw materials for various processed products.