• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.103-109
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• 2007

To investigate the effects of artificial vegetation island (AVI) on fish distribution, we compared fish fauna from artificial vegetation island (AVI) area, which installed in 2000, natural vegetation area (NVA) and vegetation-free area (VFA) at Kyungan Stream area of Lake Paldang from Jul. to Nov., 2005. Results showed that 11 families 23 genera 24 fish species were distributed in the AVI and NVA. Squalidus japonicus coreanus, a small-size fish which generally lives at the downstream, dominated absolutely in the individual numbers. However, only 6 families 11 genera 12 species of fishes caught at the VFA, and dominant fishes were Hemibarbus labeo and Erythroculter erythropterus, a medium to large-size migratory fishes which live in mid-depth of water column. The dominance index was high at the AVI (0.778) and NVA (0.868), whereas the diversity index and evenness index were high at the VFA. Fish distribution at AVI was similar to that of the NVA in numbers of species, indicating that the AVI could playa role as spawning and inhabitation zone to a variety of fishes. We believe that AVI may be used for a restoration of the damaged and disturbed littoral ecosystem.

• Parasites, Hosts and Diseases
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• v.25 no.1
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• pp.59-68
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• 1987

An epidemiological survey on Metagonimus yokogawai infection was performed in the eastern coast area of Kangwon province. Formalin-ether concentration technique and Stoll's dilution egg counting method were employed to figure out the prevalence and intensity of M. yokogawai infection and eating habits of inhabitants with raw freshwater fish. The results are summarized as follows: 1. The prevalence rate of M. yokogawai infection was 6.6% among a total of 2, 357 examinees; 8.6% (115 out of 1, 345) in male and 4.0% (40 out of 1, 012) in female. 2. The prevalence rates were different by the streams where the examinees were residing: 17.8% along the area of Ohsip-cheon (stream), 11.8% along Maeup-cheon, 1.7% along Hwasang-cheon, 1.3% along Yeongok-cheon, 0.9% along Namdae-cheon, 0.9% along Sa-cheon and 0% in the other streams (Yongchon-cheon, Kangnung Namdae-cheon and Jusoo.cheon) in decreasing order. 3. By social strata, the positive rate was 8.0% (122 out of 1, 521) in general inhabitants and 3.9% (33 out of 836) in school children. 4. By the intensity of infection by means of EPG counts in feces; the light infection (less than 400/EPG) was 74.1%, moderate infection (401-1, 000/EPG) 17.3% and heavy infection (more than 1, 001/EPG) 8.6%. 5. Twelves out of 50 sweetfish (Plecoglossus altivelis) (24%) caught from the streams in eastern coast of Kangwon-Do were infected with metacercariae of M. yokogawai, and the number of larvae detected were 70.7 per 6sh in average. The metacercarial infection rates in fish were also different by the streams; 100% in Ohsip-cheon of Samcheok-Gun, 14.3% in Sa-cheon, 16.7% in Yeongokcheon of Myeongju-Gun and 0% in Namdae-cheon of Yangyang-Gun, respectively. 6. Six hundred ninety live (695) out of 1, 396 inhabitants and school children (49.8%) were experienced in eating raw freshwater fishes (Plecoglossus altivezis, Triboledon hakonensis, Coreoperca sp., Morose sp., Carassius sp. & Cyprinus sp. and Zacco platypus). The data were assayed with the questionnaire collected from the examinees. In summarizing the above results, it is known that the Ohsip-cheon area of Samcheok-Gun is highly infected region, and the other areas of Kangnung Namdae-cheon, Yeongok-cheon and Yangyang Namdae-cheon are very lowly infected or non-infected regions for M yokogawai infection.

• Korean Journal of Ichthyology
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• v.32 no.2
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• pp.84-90
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• 2020

We investigated carbon and nitrogen isotope ratios (δ¹³C and δ¹⁵N) of the slipmouth Leiognathus nuchalis to reveal the effects of body size, feeding strategy and spatial distribution on the food resource utilization during the migration in the Seomjin estuary and Gwangyang Bay. The δ¹³C values of L. nuchalis caught in the Seomjin estuary where the salinity is lower than 30 psu were much lower than those in the deep-bay area of Gwangyang Bay. Such a spatial heterogeneity in δ¹³C values of the L. nuchalis clearly indicates active feeding within the estuarine habitat. In contrast, the δ¹⁵N values of L. nuchalis showed a consistency among sites, indicating that this species occupies identical trophic level across the whole area. The slipmouth distributed throughout the bay area, reflecting its euryhaline characteristics. However, the distribution pattern appeared to be separated according to body size into smaller individuals in the low-saline estuary and larger ones in the deep bay. Overall results support the plastic feeding strategy of the slipmouth from zooplanktonic (estuarine habitat) to epibenthic (deep-bay habitat) feeder during the migration between estuarine to deep-bay habitats.

• Korean Journal of Environmental Biology
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• v.26 no.2
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• pp.94-101
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• 2008

The aim of this study was to assess the responses of mixed function oxygenase (MFO) and antioxidative systems of feral Javelin goby, Acanthogobius hasta, caught in two sites of different pollution level in Shihwa lake, which has been a highly polluted lake by organic pollutants from nearby industrial complexes and sites. Enzymes analyzed in phase I of MFO system are cytochrome P450 (CYP), NADPH-cytochrome P450 reductase (P450R), NADH-cytochrome b5 reductase (b5R), and ethoxyresorufin deethylase (EROD). Phase II enzyme of glutathione S-transferase (GST) in MFO system was also investigated. Moreover, oxidative-enzyme system including catalase (CAT), glutathione reductase (GR) and total-glutathione peroxidase (GPX) activities and glutathione concentration in both of oxidized (GSSG) and reduced form (GSH) were determined. P450R, b5R, and GST activities of fish are relatively high in the polluted area, whereas hepatic EROD activity levels of fish in polluted area were lower than those of unpolluted area. CYP concentrations are not different between areas. These results indicated that feral Acanthogobius hasta were adaptive to highly polluted environment and exposed to oxidative stress in Shihwa lake.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.935-944
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• 2014

To elucidate the variation of species composition, biomass and size distribution of fishery resource in the Uljin marine ranching area was investigated at the 4 stations from 2009 to 2010 based on the dredge sampling. During the survey period, a total of 41 fishery resource species were sampled with a mean density of $2,554,633\;ind./km^2$ and mean biomass was $32,946kg/km^2$. A total 36 fishery resource species were sampled with a mean density of $3,198,793\;ind./km^2$ and mean biomass $41,177kg/km^2$ in 2009 and it were sampled a total 31 species, mean $1,910,473kg/km^2$ and $24,716kg/km^2$ in 2010. The major individual-dominant species, occupying over 1% of total individuals, were Gomphina veneriformis (2,491,818 ind., 82.2%), Umbonium costatum (221,973 ind., 8.7%), Mactra chinensis (49,879 ind., 2.0%), Glossaulax didyma hayashii (49,879 ind., 1.9%), Blepharipoda liberate (37,714 ind., 1.5%) and Paguridae spp. (27,266 ind., 1.1%). The major biomass-dominant species, occupying over 1% of total biomass, were G. veneriformis (25,124 kg, 76.3%), G. didyma hayashii (2,596 kg, 7.9%), M. chinensis (2,024 kg, 6.1%), Ovalipes punctatus (921 kg, 2.8%) and Glossaulax didyma didyma (567 kg, 1.7%). From the cluster analysis based on Bray-Curtis similarity matrix of fourth root transformed data of species number and individuals was divided into 2 different groups of the fishery resource community (Group A-St.1, Group B-Sts. 2, 3, 4). The 2009 and 2010 mean Shell length (mm) of G. veneriformis was 37.73 mm, 29.76 mm and M. chinensis was 62.03 mm, 44.94 mm, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.3
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• pp.184-193
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• 2008

For environment-friendly fishery, the lead sinkers of octopus drift line were developed with the environmentfriendly sinker, and their characteristics and performance were investigated. To make the environmentfriendly sinker, the hydrate ceramic material was developed, and to increase the weight and strength, the iron power was added to it. The fishing hook was machine-made, and standardized, by using 60cm iron wire. For the manufacture of the sinker, the first, the mold was made, and then, hydrate ceramic material and water were quantitatively mixed. The mixture was poured into the mold prepared with a fishing hook already inserted, and had hardened for several hour, before it was taken out of the mold as a complete sinker. The sinkers were made in the 8 types ranging in weight from 150 to 500g, and their specific gravities were diverse from 2.871 to 6.637, which was 0.19 to 0.44 times lower than that of lead. The movement of the environment-friendly sinker by flume tank was possible in the weaker current speed than the similar lead sinker. In the coastal fishing grounds of Gangwon province, the comparison of catching efficiency was made between the improved fishing gears composed of the environment-friendly sinkers and artificial baits, and the current used fishing gears of lead sinkers and pig-fat baits. The result showed the tendency in which the improved fishing gears caught the bigger octopuses than the current used fishing gears. In the quantity and number of the fish catch per unit fishing gear, the improved fishing gear showed a little more catch than the current used fishing gear, regardless of the fishing area. However, the number of the improved fishing gears lost during fishing operation was similar to that of the current used fishing gears.

• Journal of fish pathology
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• v.24 no.3
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• pp.213-223
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• 2011

Among wild marbled sole, Pleuronectes yokohamae caught in west coastal area, Chungnam, tumor-bearing fish were found. Parasites and pathogenic bacteria were not detected and CPE was not observed. Using the light microscope, the epidermal layer of wild P. yokohamae was significantly thickened compared to the normal skin. The lesion was formed papillary folds. Hypertropical epithelial cells revealed karyolysis, marked nucleolus and cloud swelled cytoplasm. In the epidermal layer of the lesion, X-cell that is characterized by oval and small pale nucleus and prominent nucleolus was observed. Dermal layer had newly formed vessels. The size of mucous cell in the papilloma lesion was significantly increased compared to the normal. In this study, no pathogens were found, so future works for finding cause of the papilloma in the P. yokohamae are needed.

• Parasites, Hosts and Diseases
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• v.30 no.4
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• pp.263-268
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• 1992

A study was presented on the anisakid larvae in Astroconger myriaster which were caught at the Southern Sea and waled at Pusan area. The nematodes were morphologically classified into Anisakis sp. and Centracgecum sp. after fixation in 70% ethanol and clearing in lactophenol. Total of 1, 768 larval anisakids were collected from 259(67.8% positive rate) out of 382 examined A. myriaster. Total 642 larvae of Anisakis sp. were obtained from 94 (24.6%) and 1, 126 Ccntracaecum sp. were recovered from 165 (43.1%) fish. The average number of worms per infected fish was 4.6. The infection rate increased according to the length of fish, and all of the fish over 71 cm were found infected. The numbers (proportions) of recovered worms by the organs were 1, 440 (80.5%) in the omentuin, 166(9.4%) in the intestine, 107(6.0%) in the stomach, 32(1.8%) in the skin, 18(1.0%) in the muscle, 13(0.7%) in the liver, and 2(0.1%) in the head. The larvae in the muscle may infect the humans who are enjoying raw sliced meat of the fish.

• Journal of Oral Medicine and Pain
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• v.21 no.1
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• pp.37-54
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• 1996

In this thesis, a new superimposition scheme using a computer vision system was proposed with 7 pairs of skull and ante-mortem photographs, which were already identified through other tests and DNA fingerprints at the Korea National Institute of Scientific Investigation. At this computer vision system, an unidentified skull was caught by video-camcoder with the MPEG and a ante-mortem photograph was scanned by scanner. These two images were processed and superimposed using pixel processing. Recognition of the individual identification by anatomical references was performed on the two superimposed images. These results were as followings. 1. For the enhancement of skull and ante-mortem photographs, various image processing schemes, such as SMOOTH, SHARPEN, EMBOSS, MOSAIC, ENGRAVE, INVERT, NEON and COLOR TO MONO, were applied using 3*5 window processing. As an image processing result of these methods, the optimal techniques were NEON, INVERT and ENGRAVE for the edge detection of skull and ante-mortem photograph. 2. Using various superimposition image processing techniques (SRCOR, SRCAND, SRCINVERT, SRCERASE, DSTINVERT, MERGEPAINT) were compared for the enhancement of image recognition. 3. By means of the video camera, the skull image was inputed directly to a computer system : superimposing it on the ante-mortem photograph made the identification more precise and time-saving. As mentioned above, this image processing techniques for the superimposition of skull and ante-mortem photographs simply used the previous approach, In other wrods, taking skull photographs and developing it to the same size as the ante-mortem photographs. This system using various image processing techniques on computer screen, a more precise and time-saving superimposition technique could be able to be applied in the area of individual identification in forensic practice.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.3
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• pp.157-164
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• 2009

Due to change of various marine environments according to seawater temperature rising, Japanese common squid(Todarodes pacificus), which was distributed in East Sea, was recently caught in Yellow Sea during a summer season from 2006. The fishery resources density research was carried out in Korea-China Provisional Water Zone using trawl fishing gear and acoustics in National Fisheries Research & Development Institute in Korea. This paper showed the analysis on the acoustical backscattering strength by two frequencies(38kHz, 120kHz) for Japanese common squid by acoustical scattering theoretical model based on size distribution for survey period, and estimate the density distribution for squid s integrated layer which was extracted from any scatterers distributed in water column using two frequency difference method which has been used to distinguish fish shoals or specific target scatterers from sound scattering layer which is composed of various zooplankton. Furthermore, the entire range of their density estimation was suggested using by Monte Carlo simulation under considering each uncertainty such as size distributions or swimming angle and so on in survey area.