• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.28 no.4
• /
• pp.337-346
• /
• 1992

Hydroacoustic surveys were conducted in the East China Sea, in the summers of 1990-1991 to investigate the distribution and migration behavior of fish, such as the diel changes in the distributions of fish, the thermoselection behavior of fish, and the fish reactions to a surveying vessel. The hydroacoustic observations were taken with a scientific echo sounder operating at 50kHz and a microcomputer-based echo processor. Fish samples were collected by bottom trawling and temperature was measured with a DBT system. The patterns of fish distributions were compared with the vertical profiles of water temperature. The results obtained can be summarized as follows: 1. The time series of hydroacoustic observations on the downward migration at dawn in the central region of East China Sea showed that the migration rate was 0.24 m/min. In this region, most of the fish collected by bottom trawling during the surveys were squid (Photologio edulis f. budo) and horse mackeral (Trachurus japonicus). 2. The hydroacoustic observations, which together associated with temperature data, indicated that squid and horse mackeral concentrated nocturally in a narrow vertical band of thermocline, particularly in summer when the survey region was strongly stratified. This result suggest that the nocturnal vertical distribution of these species evidently is controlled by temperature. 3. When the survey vessel, that is running at a speed of 11 knots, has suddenly stopped, the fish which concentrated beneath the transducer showed a strong avoidance reaction in the form of rapid downward migration. After a few minutes, the descending reaction disappeared and the fish slowly began the upward migration toward their original swimming positions. Trawl data suggest that the fish, which showed the avoidance reaction, was Liparis tessellatus.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.5
• /
• pp.725-731
• /
• 2015

Electron spin resonance (ESR) analysis was conducted for eight different kinds of dried seafood products to investigate their gamma-irradiation status. The specimens consisted of 0~10 kGy-irradiated bones, which included five dried fishes (plaice, hairtail, saury, herring, and dried filefish) and three dried mollusks (beca squid, dried squid, and mitra squid) without flesh or marrow. ESR analysis showed that irradiated specimens exhibited typical asymmetric signals as compared to non-irradiated specimens. ESR signal intensities of all dried fishery samples significantly increased depending on irradiation dose, whereas hydroxyapetite radicals clearly appeared in irradiated plaice, saury, and hairtail. In comparing hydroxyapatite (HA) ratio, irradiated hairtail showed a greater hydroxyapatite-radical generation rate than plaice and saury, and the HA ratio significantly increased with elevated irradiation dose. However, all irradiated plaice and hairtail samples, including 5 and 10 kGy-irradiated saury, showed radiation-derived radicals, whereas filefish and mollusks did not. From the results, ESR spectroscopy was found to have potential to be applied for identifying irradiated plaice, hairtail, and saury, which all contained bones.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.37 no.2
• /
• pp.85-94
• /
• 2001

The vertical distribution and activity patterns of fishes during the evening and morning transitions were investigated acoustically and by pelagic trawling on October 2-10, 1997 in the Korean Eastern Sea. The acoustic data were collected from four stations with a scientific echo sounder operating at a frequency of 38 kHz, and the echogram was used to analyze the diel vertical migration of fish. Biological sampling was accomplished by pelagic trawling to identify fish species recorded on the echograms, and the species and length compositions were investigated. Vertical profiles of water temperature, salinity at the trawl station were taken with a CTD system and were related to the diel movement and the depth distribution of fish. During the day, one group of fish mainly distributed above the depth layer of 50 m, the other group was at deeper water, approximately 250 m, but began to migrate toward the surface before sunset with a time difference. During the night, they were dispersed between the surface and the depth of 125 m. Just prior to sunrise, the scattering layer was divided with 2 groups and began to migrate downwards, respectively. Several trials of pelagic trawling for scattering layers suggest that the most dominant scatterer in the survey area of this study was Japanese flying squid, Todarodes pacificus..

• Journal of Fisheries and Marine Sciences Education
• /
• v.9 no.1
• /
• pp.71-82
• /
• 1997

The squid fishery from the East China Sea has increased in importance in recent years, for management of resources were carried out selection experments using diamond and square mesh cod-end with enclosing small mesh cover net by trouser net method during 1991-1994 year. Mesh selection studies on Short-finned squid and Long-finned squid divided from catches by trial experiments. The results that square mesh cod-end retained proportionally fewer small and undersized Short-finned squid and Long-finned squid, square mesh cod-end were greater selection factor and 50% selection length than diamond mesh cod-end.

• Analytical Science and Technology
• /
• v.29 no.6
• /
• pp.283-292
• /
• 2016

Conventional fingerprint powders used during crime scene investigations pose potential health hazards. Thus, multiple natural replacement powders, including squid ink powder, indigo and rice powder were used to develop (visualize) latent fingerprints on non-porous surfaces (e.g., glass, plastic and tile). Fingerprints developed using the natural powders were compared using the Automatic Fingerprint Identification System (AFIS) with those developed with traditional black powder. The peak areas of ridges were also compared using densitometric image analyses. Collectively, objective and quantitative evaluation methods were developed. The effectiveness of natural powders varied depending on the surface but, in general, squid ink powder performed well on most surfaces. Indigo powder performed well on tile surfaces, while rice powder performed well on glass surfaces. Plastic was the most difficult surface from which to develop fingerprints. Image analysis using Field Emission Scanning Electron Microscopy (SEM) demonstrated the importance of the size and shape of natural powder particles to properly adhere to the ridges. Although densitometric image analyses did not correlate the number of minutiae and ridge peak areas, an unbiased, objective evaluation method would be possible using image analyses with a reference image. Additional experimentation will yield safe and cost-effective natural powders with which adequate fingerprint development can be performed.

• Journal of the Korean Society of Food Culture
• /
• v.19 no.5
• /
• pp.516-523
• /
• 2004

This study was conducted to investigate the changes in the qualify of gamma-irradiated seasoned cuttle during storage. Seasoned cuttle packed in PVC film (0.06 win) was stored at $15{\pm}1^{\circ}C$ for 6 months after treatment with doses of 0 to 7 kGy. Microbial populations of seasoned cuttle were $1.6{\times}10^{5}CFU/g$ in total aerobic bacteria, $10^{4}{\sim}10^{5}CFU/g$ in yeasts &molds, and negative in coliforms, which were effectively reduced by 3 kCy or higher up to the undetectable level(<20 CFU/g). The pH and moisture content of the samples were not changed with irradiation, but moisture was some decreased during storage. The instrumental color (especially Hunter b value), pigments (lipophilic &hydrophilic) and TBA value of the samples increased with storage time as well as irradiation dose more than 3 kGy. The influence of storage condition, however, were more significant. Irradiation did not induce any changes in volatile basic nitrogen (VBN) and trimethylamine (TMA) contents, thereby maintaining their contents lower than those of the non-irradiated samples during storage by reducing the microbial load.

• Korean Journal of Food Science and Technology
• /
• v.33 no.3
• /
• pp.345-352
• /
• 2001

The volatile compounds of traditional Kyungsando squid sikhe were identified by GC-MS. The amount of ${\alpha}-zingibirene$ among identified volatile compounds was 19.73 mg/kg. The major volatile compounds of sikhe were (Z)-Di-2-propenyl disulfide, ${\alpha}-curcumene$, methyl allyl disulfide, (E, E)-a-farnesene, pentanol, z-citral, 3-ethyl-1,2-dithi-5-ene-${\beta}-elemene$, ${\beta}-elemene$, acetic acid, and ${\beta}-phellandrene$. The volatile compounds of sikhe were compose of 49 including hydrocarbone groups, 15 aldehydes groups, 33 alcohol groups kinds, 11 ketone and ester groups. The fraction obtained from sikhe were tested for electron donating ability, angiotensin converting enzyme inhibitory activity and xanthine oxidase inhibitory activity. There were no electron donating abilities$(SC_{50})$ in hexane and water soluble fractions. On the other hand, the angiotensin converting enzyme abilities of ethylacetate and butanol soluble fractions were $310.64\;{\mu}g/mL$ and $1096.49\;{\mu}g/mL$, respectively. Angiotensin converting enzyme inhibitory activities$(IC_{50})$ of ethylacetate butanol soluble fractions were 1.623 mg/mL and 1.303 mg/mL, respectively. Xanthine oxidase inhibitory activities$(IC_{50})$ of ethylacetate fraction and butanol soluble fractions were 3.591 mg/mL and 2.083 mg/mL, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.4
• /
• pp.356-360
• /
• 2000

In order to utilize the processing wastes of squid, chitosan was prepared by intermittent deacetylation treatment of ${\beta}-chitin$ richly contained in the pen of squid, and then their characteristics of chitosan and N-acetylchitosan film were studied. The acetylation time of N-acetylchitosan film-1 (N-ACE-1) manufactured from chitosan solution by treating with acetic anhydride was about 12 hrs. In SEM photomicrographs, the surface of chitosan film was regularly arranged netlike, and that of N-acetylchitosan film-2 (N-ACE-2) was rough like snowflake and larger than chitosan film. The chitosan film (thickness 0.02 mm, time 60 min) had the highest tensile strength ($1,240 kg/cm^2$) and elongation ($58.25{\%}$), N-ACP-1 (thickness 0.02 mm, time 60 min) had the highest water permeability ($539 g/m^2{\cdot}24 hrs$), oxygen permeability ($20,000 cm^3/m^2{\cdot}24 hrs{\cdot}atm$) and water uptake ($350{\%}$) among the tested films.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.29 no.3
• /
• pp.320-331
• /
• 1996

Electrophoretic comparisons of 482 individuals of Todarodes pacificus from 9 fishing areas were made to estimate genetic variability and differentiation using 17 enzymes. Strong activities were shown by 9 enzymes with 11 gene loci. The 9 sample lots could be divided into 3 genetic groups, based on dendrogram analysis using the Nei's genetic distance. The Summer, Autumn and Winter cohorts were identified as three seperated ecological populations which maintain genetic exchange. It is postulated that either the Summer cohort or the Autumn cohort has indepenently developed a local population that was isolated by hydrographic factors.

• Journal of Aquaculture
• /
• v.10 no.1
• /
• pp.87-95
• /
• 1997

This experiment was conducted for compare domestic experimental microparticulated diets with imported commercial microparticulated diets in olive flounder larvae, Paralichthys olivaceus (Temminck et Schlegel). Fish larve were fed four microparticulated diets from 8th day after hatching. Four diets were two commercial microparticulated diets D and H, and experimental microparticulated diets K1 and K2 formulated each with different protein sources (diet K1 ; squid meal, blood meal, yeast extract, chlorella powder, olive flounder muscle, Lys, and Met ; diet K2 ; whole egg protein, krill meal, short-necked clam meal, squid muscle, live yeast, yeast extract, and casein). There were no significant differences on body weight, body length and survival rates among four diet treatments up to the 40th day after hatching. At the 83th day after hatching, fish fed diet D had a significantly higher survival rate than that of fish fed diet K2, whereas there was no significant difference between to diet H and K1. Fish fed diet D had a significantly higher body weight than these of fish fed diaet K1 and K2, whereas there was no significant difference between fish fed diet D and H. There was no significant difference on EPA and DHA of body fatty acid composition among four diet treatments up to the 83th day after hatching. These results show that nutritionally well-ballanced domestic microparticulated diets for olive flouner lavae can be developed.