• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.1
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• pp.26-36
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• 2020

Thousands of pelagic and demersal fishes inhabit the waters around Korea and many of them are overexploited. One of the reasons is technological development, which increases the efficiency of the vessels continuously. The analysis was conducted to identify the change of fishing power index to develop the vessel and gear technology that may have improved the fishing efficiency of the otter trawl fishery from 1960s to 2010s. Gross tonnage was decreased stably, but horse power was increased annually. The perimeter of net mouth was somewhat longer, but little changed. Color fish finder was utilized from the mid-1960s. Hydraulic net drum were introduced in the early 1990s, and supply rate was gradually increased. Surveys on the supply and upgrading of fishing equipment utilized visiting research. Therefore, the relative fishing power index in the trawl fishery increased about two to three times in the 2010s compared to the 1980s. The results are expected to contribute to reasonable fisheries stock management.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.1
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• pp.37-44
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• 2020

The change of fishing power index was analyzed to identify the development of the vessel and gear technology that may improve the fishing efficiency of the offshore conger eel pot fishery from 1980s to 2015. Gross tonnage per fishing vessel was rapidly increased annually. The standard of pot was maintained, but the number of pot used rapidly increased by using conger eel pot hauling devices, carrying and loading devices, main line hauler, casting devices and slide type pot. Fish finder system to identify fishing ground information and the conger eel pot hauling devices were modernized, and supply rate was also increased. Therefore, the relative fishing power index in the offshore conger eel pot fishery increased from 1.0 in 1980 to 1.3 in 1990, to 1.8 in 2000 and to 2.0 in 2015. The results are expected to contribute to reasonable fisheries stock management of the offshore conger eel pot fishery.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.12-16
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• 2002

Soil, ground water and sea bed are exposed to continuous accumulation of polluted materials causing serious environmental damage. It has been reported that such pollution causes a massive mortality of fish stock in rivers by the resuspension of toxic chemicals during strong wind conditions. Therefore, it becomes apparent that there is an immediate demand for the restoration treatment of polluted river bed (or sea bed) sediment layers. Pollution levels of major rivers and ports such as Pal-dang, Kyung-an rivers, Ma-san port are becoming public concern and are posing a serious environmental threat. In particular, the pollution of Shi-hwa river has become a nation wide issue for last few years. In spite of such public concern, the pollution level of such rivers or port are getting worse everyday. In this study, an environmentally sound engineering package is introduced which helps to restore the polluted river bed or sea bed sediments. This engineering package is consisted of a suction facility followed by a series of mechanical, chemical as well as biological treatment units. The suction facility is designed to minimize the secondary pollution due to the resuspension of toxic materials during suction. The sea bed cleaning engineering package is designed to be installed on the top of a floating barge. Such combination of environmental plant and shipbuilding technology provides a cost-effective solution, minimizing the cost involved in the transportation between suction and treatment facilities.

• Journal of Fashion Business
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• v.21 no.1
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• pp.148-165
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• 2017

An assortment of daily supplies have been documented in and accounting book that Hwa-sun Song, a wholesale dealer in Hongcheon, Gangwon-do, sent to Young-hui Sin, a customer. This study analyzed a total of 163 documentations in the accounting book between 1910 to 1916, which includes types of daly supplies, trading volume, and prices, maintained accounting between. Consequently, we are able to indentify companies that produced the applicable goods, names of products, units by which goods were counted, and the lowest and highest prices prevailing, along with kinds of goods patronized in everyday life in Hongcheon in the early 20th century. Paper had the maximum trading volume. The second, most traded were cigarettes, a symbol of the new culture. These were traded under various brand names, such as Kkotpyo, Guksyu, Sanhopyo, Syonghak, and Joil. Foodstuffs, were the third most traded items, including fish, fruits, sugar, Waeddeok, Chilwaeddeok, Color candies and Okchyun candies. Our results indicate that the snack food business had developed since the 19th century. Lighting equipment, oil, candles, matches as well as traditional oil lamps and flints cornered the fourth largest stock being traded. Medications were fifth, with prescriptions written for Insohwan, Hoechyungsan and Siungo, including quinine, a medicine for malaria. Other trades included kitchen appliances such as soup bowls, porcelain bowls, kettles, and drinking cups, and a variety of daily supplies such as mirrors, mats, umbrellas, Geumjiwaemil, hair oil imported from Japan, and soap.

• Environmental and Resource Economics Review
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• v.17 no.4
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• pp.775-812
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• 2008

This paper provides a theoretical approach to the New Zealand's Catch-Balancing Regime (CBR) with a reporting requirement under the Individual Transferable Quota (ITQ) system. The enforcement strategy depicted draws on recent literature regarding practical applications of the Revelation Principle. New Zealand's use of CBR-specific instruments such as deemed values, remains to be improved. However, some of its features can constitute a valuable example for regulators seeking to improve their methods of dealing with issues as bycatch or overfishing in order to maintain Total Allowable Catch (TAC) levels under emerging ITQ systems. The enforcement strategy analyzed has the potential to provide a more sustainable and efficient management of the fish stock, reduce discarding and stabilize monitoring costs, while improving the level of reporting compliance.

• The Journal of Fisheries Business Administration
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• v.48 no.2
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• pp.19-32
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• 2017

The purpose of this study is to identify problems and suggest improvements of estimating procedures and item of fisheries supply-demand statistics served as a basis for the fisheries supply-demand policies. Korea Rural Economic Institute(KREI) and Ministry of Oceans and Fisheries(MOF) respectively publish the fisheries supply-demand statistics. But the reliability of data is low as the statistics of these two organizations are limited and show discrepancy in the numbers. It is therefore difficult to use them as the basic data for policies. Also, an accurate data aggregation is difficult due to following problems in the items of statistics. 1) Problems in estimating route sales and non-route sales of production, 2) adequacy of fishery product yield rate compared to raw material in the fisheries import/export sector, 3) selection of target companies for understand stocks and survey scope of fish species, 4) applying'0'to non-edible product demand etc. In order to develop the fisheries industry as a future growth industry, it is necessary to establish the accurate fisheries supply-demand policy as the instability of fisheries supply and demand is increasing. To do this, statistical reliability has to be improved. The improvements proposed in this study should be implemented considering urgency. First of all, an exhaustive analysis of stock statistics and conversion rates of raw material yield in the fisheries import/export sector should be conducted. In the medium term and the long term, transferring production statistics to MOF and surveys on the use demand of non-food product and the level of reduced and discarded seafood products should be carried out in consecutive order.

• Journal of Environmental Health Sciences
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• v.39 no.4
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• pp.376-382
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• 2013

Objectives: The objectives of this study were to identify the virucidal efficacy against the viral hemorrhagic septicemia virus (VHSV) of an aquatic disinfectant tablet composed of calcium hypochlorite. Methods: Virucidal efficacy was determined through the viability of VHSV contacted with the disinfectant in a viral stock cultured in a fathead minnow cell line. An aquatic disinfectant tablet and VHSV were reacted under distilled water (DW), hard water (HW) or organic matter suspension (OM) conditions. Results: Under DW and HW conditions, VHSV was inactivated with 24,000- and 2000-fold dilutions of the aquatic disinfectant tablet, respectively. With the investigation of the antiviral effect of the disinfectant under OM conditions, VHSV was inactivated with a 16,000-fold dilution of the aquatic disinfectant tablet. Conclusions: The results from this study showed that the aquatic disinfectant tablet was a highly effective disinfectant against VHSV. In the future, a controlled field trial is required to determine whether the use of an aquatic disinfectant tablet will be able to reduce VHSV in a cultured marine fish farm.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.313-320
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• 2018

Chub mackerel Scomber japonicus is an economically important pelagic species in the western North Pacific. In the last 50 years, the annual total catch in Korean waters showed large fluctuations, ranging from 100 to $420{\times}10^3tons$. To provide a biological reference point for management of chub mackerel, we applied a simulation-based yield-per-recruit (Y/R) model that considered both temperature-dependent growth and size-dependent mortality. We estimated the fisheries yield with respect to varying biological reference points and environmental conditions, including 1) the instantaneous rate of fishing mortality (F), 2) length of fish at first capture ($L_c$), and 3) water temperature. The result of our analysis showed that the Y/R could be greatest when the $L_c$ ranges from 19-27 cm and F ranges from $1.48-2.00yr^{-1}$. Y/R increases with increased water temperature between 15 and $23^{\circ}C$. We suggest targeting an $L_c$ of 17 cm (age=0.6 years) under the assumed current of $F=0.48yr^{-1}$ for maximizing the chub mackerel harvest. Further analysis considering spawning and recruitment processes are required to provide biological reference points to ensure the sustainability of chub mackerel fisheries in Korean waters.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.1
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• pp.83-88
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• 1994

For the purpose of genetic stock indentification of three species of salmonid fishs and their hybrid, lactate dehydrogenase(LDH), malate dehydrogenase(MDH), isocitrate dehydrogenase(IDH), a-gylycerophosphate dehydrogenase(a-GPDH), malic enzyme(ME), 6-phospho-gluconate dehydrogenase(6-PGD), phosphoglucose isomerase(PGI) and phospho-glucomutase(PGM) from skeletal muscle, liver, heart and gill tissues in all three species were analyzed. Chum and masu salmon showed no polymorphic patterns in all isozyme loci, however rainbow trout were found to have polymorphic patterns at MDH-B, LDH and IDH loci. Especially, significant differences were found at MDH-B loci between the three species and the IDH patterns of rainbow trout were also different from the other two species. These loci therefore can be utilized as efficient genetic markers for the identification of hybrids and improve the efficiency of fish breeding. There was no difference except PGI between diploid and triploid isozyme patterns but PGI showed some potential as a marker for triploid in masu salmon.

• Journal of Environmental Science International
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• v.31 no.10
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• pp.861-868
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• 2022

The Namdae stream in Gangneung-si is one of the rivers where salmon stock is mainly maintained by natural spawning rather than artificial seedlings. There are structures including weir, and fish distribution and movement characteristics can be different by these structures. In this study, we investigated the distribution and behavioral characteristics of salmon by sighting survey within 12 km immediately upstream of the river mouth between October 2021 and February 2022. As a result, salmon distributed within 9 km from rivermouth. There were more salmon in the lower reaches of Doosan weir than in the upper reaches of that. The main spawning ground for salmon was between 7-9 km from rivermouth and around the lower part of Doosan weir. Salmon behaved for spawning in the gravel-bed area and undercut slope of the mainstream, such as mating, digging the riverbed, and competition among males. Salmon moved more slowly in the gravel-bed area than sand-bed area. Doosan weir hinders the spawning migration of salmon by frequent flow changes and terraced fishway. This study provides primary information to understand the ecological changes of salmon by environmental changes in the Namdae stream.