• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.2
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• pp.149-161
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• 2016

Fishing characteristics of Korean tuna purse seine fishery in the Pacific Ocean were investigated using logbook data compiled from captain onboard and the statistical data from 1980 to 2014. Changes in fishing ground and correlation between marine environmental factors and fishing patterns were investigated using Oceanographic index. The proportion of unassociated set was higher than that of associated set. The catch proportion of yellowfin was higher in the unassociated set, while that of skipjack and bigeye was higher in the associated set. Due to vessels, fishing gears and Korean captains' high-level of skills in fishing technology optimized for the unassociated set and preference of large fishes, especially large yellowfin tuna, it showed unique fishing characteristics focusing on the unassociated set. As for fishing distributions of Korean tuna purse seine fishery and impacts of oceanographic conditions on the fishery, the main fishing ground was concentrated on the area of $5^{\circ}N{\sim}10^{\circ}S$, $140^{\circ}E{\sim}180^{\circ}$ through the decades. When stronger El-nino occurred, the range of fishing ground tended to expand and main fishing ground moved to the eastern part of western and central Pacific Ocean. During this season, yellowfin tuna had high CPUE and catch proportion of yellowfin tuna in the eastern part also increased. As for the proportion of fishing effort by set type, proportion of log associated set was high during El-nino season while that of FAD associated set was high during La-nina season.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.4
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• pp.263-270
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• 2005

This paper summarizes characteristics of the Korean tuna purse seine fishery in the Western and Central Pacific Ocean (WCPO). Major fishing area for the Korean tuna purse seine fleet consisted of the waters of Micronesia, Papua New Guinea and Solomon Islands and adjacent high seas between $130^{\circ}E-180^{\circ}$ The center of the Korean tuna fishing ground was in the vicinity of $180^{\circ}$ during the El - $Ni{\tilde{n}}$o event but was formed in $150^{\circ}-160^{\circ}$E during the La - $Ni{\tilde{n}}o$ event. As compared with other major purse seine fleets in WCPO, the Korean fleet set more on unassociated schools of tuna, while Japan, USA and Chinese - Taipei fleets accounted for more than 50% of sets on log - associated schools. In general, CPUES for log - associated schools were higher than those for unassociated schools and catch composition showed that yellowfin ratio was higher in unassociated shools than log - associated schools. Length frequency represented higher percentage of mid - sized yellowfin than Japanese and USA fleets. Daily set numbers and CPUE were high before 7 am and remained almost constant from 7 am to 3 pm but decreased rapidly after 3 pm and 5 pm, respectively. Catch composition per set indicated that pure skipjack school was caught most frequently, followed by mixed school and pure yellowfin school as the least, but CPUE was highest for the mixed school.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.3
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• pp.243-249
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• 1999

Specificity of catches has been analyzed to japanese tuna purse seine A principle component analysis was used to improve the efficiency of fishing and increase sustainable production and productivity of Korean tuna purse seine.The result are as follows;From the principal component analysis of the fish catches, the first principal component(Z1) to promote principal component score was skipjack Kastsuwonus Pelamis, LINNAEUS and yellowfin tuna Thunnus Albacares, BONNATERRE (Small : smaller than 10kg) and proportion was 86.8% of total. The second principal component(Z2) to increase principal component score was yellowfin tuna (Large : larger than 10kg) and proportion was 9.5%.On the other hand, fish operating that have caught skipjack and yellowfin tuna (Small and Larger) was not so much. Fish catches for one species raised volume of the catches while catches for multi-species decreased it since principal composition score for one species and both species together has been increased.Fish school could be divided into three groups of schools each of which was associated with drift objects, payaho and ship, school associated with shark, whale and porpoise and school of breezing, feeding and jumping from proportion of principal component analysis for fish catches of school types. However, the biological pattern is different among school associated with ship, payaho and school associated with drift objects for analysis eigen vector. School associated with ship, payaho and school associated with drifting object associated is judged as school which be assembled to vessel and drifted log temporary.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.4
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• pp.21-31
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• 1986

The author investigated the relation between the catches of tuna species and the distribution of horizontal mean temperature at the Jepth of 10m and of vertical temperture sections in the different fishing grounds, using the date of catches in 1980, showing a relative good ones during six years from 1975 to 1980, and of oceanographic observations. Yellowfin and bigeye are mainly caught in South Equatorial Current regions including equatorial upwelling region in 5$^{\circ}$N to 5$^{\circ}$S, and albacore is mainly caught in Subtropical region in 20$^{\circ}$5 to 40$^{\circ}$5. The good fishing grounds of yellowfin and bigeye are made in the depth layer of 100 m to 250 m and temperature of 15$^{\circ}$C to 26$^{\circ}$C having a smooth gradient of thermocline in the Central Pacific between 180$^{\circ}$ and 1500W. But albacore is caught well in which the temperature of thermocline ranges from 100e to 25$^{\circ}$C and its gradient very smoothly. Approaching to the American Continent, the catches of yellowfin and big eye decrease because the thermocline becomes shallower and steeper at Eastern Pacific Region between 1500 and 800W.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.584-590
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• 2011

This study aimed to demonstrate the bioadhesive characteristics of gelatin biofilm to rat skin. The biofilm was manufactured from gelatin extracted from the acetic acid treated-skin of the yellowfin tuna Thunnus albacares. The bioadhesive strength of tuna gelatin biofilm was compared to that of porcine gelatin biofilm. The tuna gelatin biofilm exhibited a higher bioadhesive strength than the porcine gelatin biofilm. Gelatin biofilm was subjected to glutaraldehyde treatment at different concentrations, temperatures and pH in order to improve its bioadhesive strength. Glutaraldehyde treatment improved the bioadhesive strength of gelatin biofilm up to three-fold. The bioadhesive strength of glutaraldehyde treated-biofilm was significantly decreased by application of sodium borohydride.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.716-723
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• 1993

To utilize effectively fish skin wasted from fish processing, a yellowfin sole skin gelatin was prepared by alkaline extraction method and the physico-chemical properties were examined. Conditions for the suitable extraction and decolorization for gelatin preparation from yellowfin sole skin are as follows: the skin is limed with 1.5% calcium hydroxide solution at $5^{\circ}C$ for 5 days, washed throughly with tap water, extracted with 6 volumes of water ($pH5.0{\sim}7.0$) to dehydrated skin for 3 hours at $50^{\circ}C$, and then bleached with 3% activated carbon. Though yellowfin sole skin gelatin was prepared under above condition, the physico-chemical property values such the melting point and gelling point of that were lower than those of pork skin gelatin. Therefore, the purified yellowfin sole skin gelatin requires a suitable modification operation for more a good quality gelatin manufacture.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.714-718
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• 1997

The tendency of rancidity in roasted and/or reheated yellowfin sole and yellow croaker was investigated as typical white muscled fish. In fatty acid composition of the total lipid, saturated fatty acid was $27.4\%,\;33.4\%$; monoenoic acid, $36.5\%,\;38.7\%$ and polyenoic acid, $34.5\%,\;26.5\%$ in yellowfin sole and yellow croaker, respectively. The ratio of unsaturated fatty acid (UFA)/saturated fatty acid (SFA) were 2,6, 2.0 and content of total lipid was $1.4\%,\;0.8\%$, respectively. Peroxide content decreased after heating in yellowfin sole while decreased after heating and tended to increase after reheating in yellow croaker. Thiobarbituric acid value increased during roasting and heating in all the samples but decreased after reheating. Acid value increased after roasting, heating and reheating in all samples, particularly higher in yellowfin sole which have a high content of UFA. Conjugated dienes continuously increased during the repeats of heating, showing more increase in the fillet with Skin than the skinless.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.1
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• pp.64-70
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• 1996

Kinetic properties of typsins purified from dark-fleshed fish (anchovy, mackerel, yellowfin tuna, and albacore) were examined and analyzed on $benzoyl-_{D,L}-arginine-p-nitroanilide\;(BAPNA)$. The values of Km' and $k_{cat}$ of the purified trypsins from the four dark-fleshed fish were found to be $49.3{\mu}M$ and $90.9\;min^{-1}$ for anchovy, $53.7{\mu}M$ and $61.2min-^{-1}$ for mackerel A, $96.5{\mu}M$ and $76.6min^{-1}$ for mackerel B, $62.8{\mu}M$ and $46.6min^{-1}$ for yellowfin tuna, and $98.3{\mu}M$ and $47.7min^{-1}$ for albacore, respectively. The values of $K_i$ on $tosyl-_L-lysine$ chloromethyl ketone (TLCK) were determined to be $20.90{\mu}M$ for anchovy trypsin, $2.86{\mu}M$ for mackerel trypsin A, $3.90{\mu}M$ for mackerel trypsin B, $0.96{\mu}M$ for yellowfin tuna trypsin, and $1.82{\mu}M$ for albacore trypsin. Thus yellowfin tuna trypsin was the most sensitive to TLCK among all trypsins. The activities and catalytic efficiency of the trypsins purified from the temperate zone fish, anchovy and mackerel, were higher than those of the trypsins purified from yellowfin tuna and albacore which migrate widely from the tropic zone to the temperate zone.

• Preventive Nutrition and Food Science
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• v.13 no.1
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• pp.7-11
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• 2008

To improve the utilization of fish processing by-products, fish oils were extracted from hoki, yellowfin sole, mackerel, and horse mackerel, and their compositions were examined. The proximate compositions obtained for these 4 species of by-product revealed they were composed of 68.1$\sim$78.1% moisture, 1.2$\sim$1.6% ash, and 13.8$\sim$18.8% protein. Fish oils extracted from the hoki, yellowfin sole, mackerel, and horse mackerel were 5.5, 9.4, 13.4, and 10.3%, respectively. The total lipids extracted from the by-products of the 4 species were 6.21, 10.43, 12.81 and 10.06%, of which neutral lipids accounted for 77.38, 77.46, 87.21 and 86.79%, respectively. Neutral lipid analysis by TLC showed that triacylglycerol was the major component, while 1,3- and 1,2-diacylglycerols, free fatty acids, free sterols, and sterol esters were present as minor components. The major fatty acids were palmitic acid, stearic acid, and oleic acid. DHA and EPA were contained at levels of 0.2$\sim$4.7% and 3.7$\sim$9.5%, respectively, in the 4 types of fish oil. The fish oils extracted from the dark muscle fish, mackerel and horse mackerel, had greater polyunsaturated fatty acid (PUFA) contents than those of the white muscle fish species, hoki and yellowfin sole.

• Korean Journal of Food Science and Technology
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• v.9 no.1
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• pp.47-60
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• 1977

A $7{\sim}10%$ aqueous phosphate solution comprised of 85% sodium tripolyphosphate and 15% sodium hexametaphosphate was injected into tuna flesh prior to precook until the fish weight increased approximately $4{\sim}10%$. The experiments were conducted at a commercial tuna processing plant using Yellowfin tuna (Thunnus albacares) of $45{\sim}68kg$ and $7.3{\sim}10.5kg$ sizes, and Skipjack tuna (Euthynnus pelamis) of $4.5{\sim}5.0kg$ size. The experimental results showed that the phosphate treatment resulted in: 1. Approximately $5{\sim}8%$ increase in yield and somewhat more moist meat with the large Yellowfin. 2. Approximately $3{\sim}8%$ increase in yield with the smaller Yellowfin. 3. Approximately $1{\sim}4%$ increase in yield with the Skipjack. 4. Minimal improvement in color and flavor.