• Korean Journal of Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.25-32
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• 1969

The estimated annual catch of river fishes in the lower part of the Naktong River was derived from the questionnaire, as a part of the fundamental investigation which was carried out for the development of fisheries In that region during the period of May 1967, to June 1968. The data were submitted by fishermen, and the area covered for the present investigation is shown in Fig.1. The annual catch of the region was estimated to be about 500 tons, excluding the mussel Cerbicula elatior. Prussian carp Carassius carassius was the largest in amount followed by com-mon carp Cyprinus carpio, and then goby Synechogobius hasta, Japanese eel Anguilla japonica, mullet Mugil cephalus, ect. and in that order. Major species of the fishes of this region belong to the carp family Cyprinidae, its species counting 23 from the collection during the observation period, and the total number of species was 40, these belonging to 14 families. But occasional severe drought heavily increase the salt content of the region, and at that time the major catch of fish becomes marine fishes such as Harengula zunasi, Clupanodon Punctatus, etc.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.2
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• pp.95-100
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• 2005

In order to improve the gill nets for croaker, Miichthys miiuy which is proper to the fishermen's income ans fisheries resource management, we had studied to the net height of present gill nets (mesh size 160mm, 50 mesh in depth), experimental gill nets-I(mesh size 150mm, 68 mesh in depth) and experimental gill nets-II(mesh size 142mm, 75 mesh in depth) in wter using the gill nets design ans analysis simulation system, and then investigated and analyzed the catch efficiency of each gill nets through the field fishing experiments. The net height of emperimental gill nets-I and experimental gill nets-II in water were estimated respectively about 1.5 times and 1.3 times higher than present gill nets which the net height is about 3.5m as the results of simulation considering the current of fishing fields. Total number of croakers which were caught by the persent gill nets was 62(body length 300~1,200mm), total catch weight was 398.7kg (mean 0.6kg/sheet). Total number of croakers which were caught by the experimental gill nets- I was 68(body length 600~1,100mm), total catch weight was 391.6kg (mean 1.2kg/sheet). Total number of croakers which were caught by the experimental gill nets-II was 28(body length 400~900mm), total catch weight was 99.2kg (mean 0.3kg/sheet).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.2
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• pp.147-155
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• 2005

This study was conducted in order to improve the automatic fishing operation system for anchovy boat seine by comparison with the fishing gear geometry and efficiency using the labor saving nets and the combined type net with midwater trawl. Field experiments were carried out to observe the geometry of nets and improve the fishing operation system by catcher boats. The vertical net opening of fore wing net, square, fore bag net and after bag net of the combined type net were varied in the range of 9.9~12.9. 16.2~28.2, 6.8~12.1 and 9.5~15.2m respectively, when the towing speed was 1.0m/sec and the distance between boats were 100m, 200m, 300m. The vertical net opening of the combined type nets was gradually decreased as function of with increasing the distance between catcher boats. Labor saving net which was maintained the net opening and towing depth stable was more suitable for the automatic hauling operation system by improvement of bag net rather than the combined type nets which was impossible in swallow depth and near to anchovy school. 3 boats hauling operation system of the labor saving net was carried out by crane with power block in 2 catcher boats for improvement of hauling operation and pushing equipment of anchovy cooking system in the processing boat for maintain more anchovy in dry frame. From the results of field experiments, 3 boats hauling operation system with power block and improved cooking system was very 3 boats hauling operation system with power block and improved cooking system was very useful and more practical as hauling time 20~35min and No. of fishermen 12~13 in comparison with the traditional system such as hauling time 30~50 min and No. of fishmen 28~38.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.2
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• pp.1-6
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• 1986

Even though it is well known that the tidal current in the East China Sea rotates clockwise, few report can be found about the precise pattern of it. To furnish some information available for the stow net fishermen, the author carried out the observation over 235 semidiurnal tidal cycle to investigate the pattern of the set and the rate of tidal current in the Korean fishing section 250 and 494, by reading the current meter and by tracing the corner reflectors with radar onboard the anchored obsen'ation vessel, from May 12, 1984 through February 27, 1986. The results obtained are as follows: 1. The mean semidiurnal tidal cycle was 12 h 20 m during spring tide, and 12 h 30 m during neap tide. 2. The mean interval from the calculated time of high water until the current began to set north was 2 h 30 m and 2 h 15 m in the fishing section 250 and 494 respectively, and the mean interval from the time of low water current began to set south was about 2 h 0 m in both sections. 3. In comparison of the occupied times to vary the set from one of 8 principal bearing points to the neighboring one, the shortest was while the set varied from N to NE and S to SW in the section 250 and 494 respectively. Contrary the longest was while the set varied from SE to S and from W to NW in the section 250 and 494 respectively. 4. In comparison of the rate while the set varied from one of 8 principal bearing points to the neighboring one, the fastest was while the set varied from SE to Sand NW to N in the section 250, and E to SE and W to NW in the section 494. Contrary the slowest was while the current set to NE and S W in the section 250, and N, NE and S W in the section 494.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.1
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• pp.41-48
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• 2017

Encircling gill net fishery is a kind of gill net which is generally used in shallow coastal waters. After the fish have been encircled by the gill net, noise stimulus such as a stone or sound is used to force them to gill or entangle themselves in the netting surrounding them. Although the fishing by a stone is a traditional fishing method, it is considered as an illegal fishing method by physical stimulus such as explosives and mechanical vibrator. However, this illegal fishing method has raised some problems to the fishing boat of other fisheries or many anglers due to disturb aggregating fish schools. This study is aimed to provide scientific base data to verify whether to impact the ecosystem caused by this encircling gill net. This study exhibited that the impulse noise by concrete sphere in the encircling gill net was $159dB/{\mu}Pa$, the ambient noise from ship engine was $160dB/{\mu}Pa$, and the maximum noise from continuous artificial vibrator was $175dB/{\mu}Pa$. These may be stimulus to the escape of fish distributed in a wide area in its natural state; it is not likely the cause of death due to catastrophic stress. Therefore, it needs to prepare the consideration of standard limit on fishing stimulus in fishing methods of the fishery laws and regulations, prevent fishermen form using illegal fishing gear (i.e. explosive sound standards: $200{\sim}220dB/{\mu}Pa$ and provide them with countermeasures.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.5
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• pp.459-473
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• 2014

The recent mass appearances of jellyfish in Korea have caused economic and social damage, as they plague swimmers and fishermen. However, jellyfish have high economic and nutritional value, and contain low levels of calories and hydrolysates. Thus, jellyfish are a natural, healthy food that can improve high blood pressure, bronchitis, and a multitude of other diseases. Here, we present research on the ecology, classification, bloom, damage caused, food component characterization, and tissues of jellyfish, with the aim of facilitating further study. Research on use of jellyfish as salted products, and for collagen and qniumucin would also be valuable. A jellyfish body is classified into three parts: the body, termed the umbrella; the oral arm; and the tentacle. Jellyfish are planktonic marine members of a group of invertebrate animals comprising the classes Schypozoa (phylum Cnidaria) and Cuboza. In Korea in 2012, jellyfish damage resulted in decreases of annual catch and commercial value estimated at 177 and 141 billion won, respectively. Because concentrations of heavy metals are below the safety limits for seafood, dried jellyfish appear to be safe raw materials for food. The proximate compositions of Nemopilema nomurai and Aurelia aurita were 97.1% and 96.5% moisture, 0.9% and 1.2% crude proteins, undetected and 0.1% crude lipids, and 1.7% and 1.8% ash, respectively. According to their total contents of essential, total, and non-essential amino acids, jellyfish gonads were deemed good-quality protein. Because the major functional components of jellyfish are collagen and qniumucin, jellyfish can be used salted, or these components of healthy diets can be extracted from them. For more effective use of jellyfish, unit costs should be decreased and safety guaranteed. Additionally, dehydrators attached to conveyor belts should be developed. Since jellyfish can be used throughout the year, they should be listed in the Korean Food Standards Codex as a food source.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.445-453
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• 2013

Walleye pollock Theragra chalcogramma fisheries in Korean waters have changed dramatically during the last three decades: the highest catches occurred in 1981, followed by continuous decreases through the 1990s, ending with a complete collapse of the population in the 2000s. The major spawning ground of walleye pollock is located in North Korean waters, and some juveniles (called nogari in Korean, <300 mm) migrate to the south for feeding and growth. Since the 1960s, Korean fishermen have often caught juveniles, and the weight (metric tons) of juvenile catch was recorded from 1975-1997. However, because the walleye pollock were not aged, the population age structure was not delineated. We developed a model to estimate the number of walleye pollock of each size class based on catch statistics of adults and juveniles, the catch proportion of each size class, and length and weight information on specimens collected by Danish-seine and drift-gill-net fisheries. The model results demonstrated that the recruitment size of walleye pollock was consistently within the 200-250mm size class, and the highest number of this size class occurred in 1981, although values greatly fluctuated interannually. The number of juvenile pollock was 10.4 times higher than that of adult pollock during 1975-1997. The total yield of juvenile pollock was 0.95 million tons, which was equivalent to about 68.2% of total pollock production. The number of juvenile pollock caught during the same period, however, was 16 billion, comprising about 91.2% of the total number caught. Such high fishing pressure on juvenile pollock is considered one of the main factors causing the collapse of the pollock population.

• The Journal of Fisheries Business Administration
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• v.26 no.1
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• pp.79-104
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• 1995

Dividend Policy involves the decision to pay out earnings versus retaining them for reinvestment in the firm, and dividend policy decisions can have either favorable or unfavorable effects on the attainment of firm's objective. This paper is to examine the present status of dividend policy of the Pusan Cooperative Fish Market, and to suggest the optimal dividend policy decisions appropriate for achieving its objective, which is to promote the fishermen's benefits and protect the interest of consumers. There are two types of dividend that the Pusan Cooperative Fish Market pays to the equity owners : (1) dividend on capital and (2) equalized patronage dividend. During'90s, while the rate of dividend on capital ranged from 1.7% to 2.8%, that of equalized patronage dividend ranged from 13.9% to 22.9%. Therefore, the rate of total dividend on capital including revolving funds has been about 20%, which turns out to be much higher than those of companies listed in the stock market. According to the current dividend data, the Pusan Cooperative Fish Market focuses on the equalized patronage dividend and the dividen on capital is the secondary type of dividend. In addition, the interesting feature of equalized patronage dividend is that it is supposed to be reinvested into capital by the Articles of the Fish Market, as soon as the Fish Market pays it to its members. Finally, this paper suggests the rational dividend policy of the Fish Market that is able to help its objective to be achidved more efficiently. The overall direction of the rational dividend policy can be summarized as follows ; (1) The level of cash dividend on capital should be increased enough to reflect the market interest rate. (2) The subsidy of working capital to some member fisheries cooperatives as quasi- dividend should be cut off steadily. (3) The equalized patronage dividend should be replaced by the original patronage dividend whose level is determined by the volume of each member's purchase. (4) In the long-term, it is necessary to improve the system of revolving funds in the way that revoloving funds could serve to complement equity capital for only a fixed time, after which they ard repaid to the members.

• The Journal of Fisheries Business Administration
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• v.26 no.1
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• pp.9-27
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• 1995

From now on, the direction of fishery products circulation measure should be improved the system to give just the right of free choice of sale route like retail, direct sale, direct dealings and direct shipping only for fishermen to produce them diversifing the function and the role of current fish market in the production to prepare the fishery internationalization, to improve the competitiveness of coastal and off-shore fishery. Practically wholesale market in land and fish market in the production have the different function and role, the organization of wholesale market in land can't substitute the essential function and role which fish market in the production should perform. So far, fisheries cooperatives as a managing subject of fish market in the production have depended on the consignment sales and purchases of fishery products but, from now on, it should be explore the widespread supply way of fishery products by producing value - added fishery products that should bring higher demand from the consumers, producer - consumer direct marketing system through not only consignment sales but also direct sales that common processing and manufacturing system of fishery products under the management of FC has been established. The direction of the idealest structural improvement of fishery production circulation organization is to establish the the position of the fishery retail price leader based on the standard of market in the fisheries production due to existing characteristics of fisheries, accordingly, to harmony the market organization of direct transportation, direct sales and direct dealings form by producer and group of producers with market organization in the fisheries production, and to make the condition to do the appropriate distributive function.

• The Journal of Fisheries Business Administration
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• v.43 no.3
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• pp.43-57
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• 2012

According to the result of the recent survey on the current condition of loss of the fishing gears in the East, West and South seas, it is estimated that 50% of the fishing gears used for coastal trap and gill net fisheries are lost every year and 20~30% of those used for inshore trap and gill net fisheries are lost. It is reported that such loss of fishing gears leads to the loss of about 10% of 1.7M tons of the total annual catch from the gill nets and traps along the country's coasts and shores, which amounts to 15~170K tons. Submerged marine litters that have recently been accumulated because of the washed out or lost fishing gears significantly affect the development of fisheries resources as well as the natural environment. The purpose of this study is to identify the damages that the ever-increasing submerged marine litters of washed out fishing gears would have on the fishery and to analyze the effects of the coastal and inshore submerged marine litter collection business on the fishery management. For this, the economic analysis was carried out for the coastal and inshore submerged marine litter collection business based on the fishermen's expenses and earnings and their catch. The result of the analysis shows that the submerged marine litter collection business is quite effective in certain areas but rarely effective in other areas. However, taking into consideration that the litter collection would contribute to protecting the marine environment as well as the fisheries resources, it is expected to have a significant impact on the protection of the marine environment even in those areas where it is not effective for the protection of the fisheries resources.