• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.2
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• pp.113-120
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• 2022

The purpose of this study is to provide information about annual variations in catch size and changes in reproductive biology in the common octopus, Octopus vulgaris, a commercially important species in Jeju Island. Samples were collected from coastal waters of Jeju Island, Korea by coastal trap fishery from January to November 2021. Octopus vulgaris have been decreasing in this region since 1984. The mantle length (ML) ranged from 4.5 to 17.8 cm and body weight (BW) ranged form 88.5 to 2,657.5 g. A χ²-test revealed that the number of males was significantly greater than females (χ² = 32.712, df = 10, P<0.05). Mature females were found from January to July and male occurred January to August. The gonadosomatic index value was higher from July to August than other months. The relationship between mantle length and body weight was BW = 2.4527ML^2.3139 (female) and BW = 2.6785ML^2.3159 (male). At 50% group maturity, female and male average weight was estimated to be 554.7 g and 330.6 g, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.2
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• pp.173-180
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• 2018

Marine casualties of small fishing vessels (SFV) of less than 20 tons are frequent in Korea. The analysis was conducted to identify the cause and then prepared reduction plan using the marine casualty statistics of fishing vessels for the last five years from 2012 to 2016 by the Korean Maritime Safety Tribunal to reduce the marine casualties of SFV. According to the analysis of the type of whole vessels occurring marine casualty, fishing vessels accounted for an average 68.0 %; moreover, except for 2014 when M/V SEWOL ferry capsizing occurred, the rate of death and missing due to marine casualties occurred from 68.3 % to 91.2 % in fishing vessels, and an average 79.5 % was found to be urgent need of a measure. Marine casualties occurrence depending on the gross tonnage of fishing vessel was found that the most occurred at less than 5 tons, followed by the order of 5 to 10 tons or less. However, crews who boarded on SFV do not have any training program for them, except for the fishing safety training of fisher who carry out fishing for shipowners and crew of the coastal and offshore fishing vessel in accordance with the safety regulations for fishing vessels in the Fisheries Cooperative Association. Therefore, it is necessary to revise the training program so as to improve the preventive action and then emergency response including the fishing safety compliance with each fishery, safe navigation, machinery inspection and emergency response. Also, an SFV of less than 5 tons of 56,000 vessels is boarded by unqualified fishers. It would also be possible to consider subdividing small boat operator's certificate to enhance their qualifications. It is expected that marine casualties of SFV will be reduced if active efforts are made to improve the safety consciousness of fisher and shipowners as well as the reorganization of fishing safety training and the small boat operator's certificate system.

• KSBB Journal
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• v.23 no.6
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• pp.489-493
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• 2008

Although the seafood cooking drips were the byproducts from the fishery industry and being wasted, it had many nutrients including proteins. In this study, the effect of a gamma irradiation on the cooking drips from Hizikia fusiformis, Enteroctopus dofleni and Thunnus thynnus were investigated. The cooking drips were extracted with 70% ethanol solution, and the extracts were analysed for the protein concentration by three different methods of Lowry, BCA and Kjeldahl. The extracts were irradiated with different doses and the protein contents were compared with respect to the absorbed doses. Total content of the proteins was increased with increasing irradiation dose. The change of protein pattern in the irradiated cooking drips was also confirmed by SDS-PAGE analysis. These results shown that the proteins in cooking drips could be unfolded or aggregated by the irradiation. Therefore, gamma irradiation could be considered as an effective method for extracting useful proteins.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.4
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• pp.1129-1135
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• 2015

The stow net is a stationary gear made from netting, usually in shape like trawl net without wings. The nets are fixed by means of anchors, placed according to the direction and strength of the current. And the commercial fishing is associated with high rate of fatal and non-fatal occupational injury. The hazard factors analysis for the fishermen's safety of offshore stow nets vessel was conducted to serve as a basic data for improving the healthy and safe working environment of fishermen using fishermen's occupational accidents of the national federation of fisheries cooperatives (NFFC) from 2012 to 2014 (n=1,144). As a result, the average occupational accident occurrence rate of this fishery was 206.9‰ in all industries 36.9 times the rate of that. In addition, average death and missing rate was found to have a very serious level management to 50.4‰ in all industries of death of 42.0 times. The accident occurred in 84.5 to 94.6% was happened at sea. The struck by object, slipping, contact with machinery, contact by object or gear and others occurred more frequently in order on the frequency of accident occurrence pattern. However, the occurrence rate of death and missing did not match the frequency of accident pattern. In other words, slipping occurred frequently higher while death and missing risk was not high. And the contact with fishing gear and fall in the waters was low while death and missing risk was high. The results are expected to contribute for identification and assessment of safety hazard occurred in offshore stow nets vessel.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.569-576
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• 1995

Quality changes of canned smoked-oyster in cottonseed oil (SOCO) were investigated to determine an optimal Fo-value ( Fo) for microbiological safety and quality stability during long-term storage. The canned SOCOs were sterilized at $105^{\circ}C,\;110^{\circ}C,\;and\;115^{\circ}C$ with various Fo-values and stored at temperature range of $5^{\circ}C\;-\;50^{\circ}C$. No remarkable quality changes in pin, content of amino nitrogen, arid value and thiobarbituric acid value of the canned SOCOs sterilized at $110^{\circ}C$ with $Fo\geq5.92 min,$ were recognized at all storage temperatures. Same tendency was also recognized in the products sterilized at $105^{\circ}C\;and\;150^{\circ}C$ with $Fo=5,50\pm 0.1 min\;and\;6.50\pm0.1 min,$ while those of the canned SOCOs sterilized at $110^{\circ}C\;with\;Fo<5.92 min$ altered remarkably.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.69-70
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• 2013

IPCC (International Panel on Climate Change) reported that the arctic sea-ice extent has been decreased by 2.7% per decades since satellite observations in 1978. The decreased sea-ice extent has gained an international attention due to its economical benefits from the NSR (Northen Sea Route). The NRS - not a clearly defined single route, but a number of alternative routes across the top of Russiahas a 37 % reduction in sailing distance, comparing to the SSR (Southen Sea Route) passing thourgh the Suez Canal. Sailing days are consequently reduced from 30 days to 20 days. Also, it is estimated that the Northen Sea has 20 to 25% of world's oil resources and occupies 40% of the world's fishery production. As Republic of Korea was admitted as an observer to the Arctic Council on May 15, 2013, there has been increasing needs to explore new route in the Northen Sea. In this situation, Korea Institute of Ocean Science & Technology (KIOST) is preparing a plan for the development of Arctic-circle Ocean Environmental Information System to support the ice navigation and resource exploration in the Arctic. We will introduce a conceptual design of a satellite-based ice navigation supporting system for the northern sea route.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.3
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• pp.209-219
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• 2016

The survey was conducted to investigate biomass and distribution of fisheries resources using a quantitative echo sounder and a fixed gillnet around Marado coast of Jeju to obtain the scientific basic data for dispute resolution with a large purse seine fishery and coastal fishing and policy establishment of reasonable fisheries resources. Hydroacoustic surveys were conducted six times (November 28~29, 2015 (night), February 23~24, 2016 (night) and March 3~4, 2016 (night/day), March 30~31, 2016 (night/day)) using a quantitative echo sounder. The pelagic fish densities were relatively higher around Marado in November 2015, February 2016 and March 3~4, 2016. However, demersal fish densities were relatively higher in Jeju coastal waters on March 30~31, 2016. Catch data using fixed gill net were used to calculate biomass. Based on the hydroacoustic data, fish length-weight function and target strength information of dominant fish, the biomass of fishes were estimated as follow: 5.64 ton CV = 70.2% at night on November 28-29 2015, 7.14 ton CV = 35.8% of pelagic fish and 530.77 ton CV = 34.6% of demersal fishes at night on February 23-24 2016, 2.34 ton CV = 56.7% of pelagic fish and 571.93 ton CV = 40.3% of demersal fish at daytime, 1.39 ton CV = 48.4% of pelagic fish and 194.59 ton CV = 54.3% of demersal fish at night on March 3~4 2016, 0.37 ton CV = 72.9% of pelagic fish and 338.79 ton CV = 99.7% of demersal fish at daytime, 0.24 ton CV = 21.3% of pelagic fish and 68.61 ton CV = 53.8% of demersal fish at night on March 30~31 2016.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.831-837
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• 1999

Ochratoxin A (OA), a naturally occurring mycotoxin, has been known to cause renal and hepatic lesion in human and animals. This study was carried out to investigate the modulation effects of antioxidant vitamins on OA-induced lipid peroxidation associated with oxidative damage. Vitamin C (10 mg/kg/day) and vitamin E (63.8 mg/kg/day) were administered by intraperitoneal (i.p.) injection to male ICR mice, and 1 hr later, OA which was dissolved in 0.1 M $NaHCO_3$, treated 4 mg/kg/day by i.p. injection. During 4 days repeated, and then measured superoxide dismutase (SOD) activity, catalase activity and malondialdehyde (MDA) formation in microsomes of liver and kidney. Additionally, the relationship between cell damage and modulation effects of antioxidant vitamins was evaluated by comet assay. Results were as followed; i) SOD, catalase activity and MDA level were significantly increased by OA treated, ii) SOD, catalase activity and MDA formation were significantly decreased by antioxidant vitamins combine treated, iii) blood cell damage associated with lipid peroxidation, induced by OA, also modulated by antioxidant vitamins. These results indicated that antioxidant vitamins might be used for prevention of renal and hepatic damage due to ochratoxicosis.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1339-1344
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• 1998

To develop natural flavoring substances, optimal hydrolysis conditions for two stage enzyme hydrolysates (TSEH) using small kingfish (Maegari) were investigated. The optimal conditions for TSEH were revealed in temperature at $50^{\circ}C$ for 3 hours digestion with alcalase (Aroase AP-10, pH 8.0) at the 1st stage and 2 hours digestion at $45^{\circ}C$ with neutrase (Pandidase NP-2, pH 6.0) at the 2nd stage. From the results in quality tests of water extracts, autolytic extracts and 4 kinds of enzyme hydrolysates, TSEH processing method was superior to other methods on the aspects of yield, nitrogen contents, taste such as umami intensity and inhibition of off-flavor formation, and transparency of extracts. We may conclude that TSEH from small kingfish was more flavorable compared with the conventional seasoning materials, it could be utilized as the seasoning substances for fisheries processing.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.537-541
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• 1999

Fish heads of the main by-product is fishery processing were treated to extract nutrients by heating the fish heads with 1.5 or 3.0 times added water during 9, 12 or 15 hours. The yield, chemical compositions and physical properties of the hydrothermal extracts were studied. The yield was increased with the amount of water added and the extracting hours. The extract contained about $80\%$ protein in solid basis, but has no lipid. In essential amino acid, glutamic acid was most abundant and Iysine was abundant. In free amino acid, $\delta$-hydroxylysine and L-histidine in Cypyrinus carpio linnaeus had 5 times more than those in Onchorhynchus keta, The solution of the extracts was known as Newtonian fluid and the color of the extracts showed lower whiteness, higher redness and higher yellowness.