• Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.221-227
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• 2015

We analyzed the small-scale purse-seine gear that is used along the North Coast of Java, Indonesia, using computer-aided tools to modify the gear. Data from the middle position of the leadline showed that the maximum depth reached by the net was 30 m. A similar result was also calculated. According to the calculated result, the mean sinking speed of the current gear at the middle position of the leadline was 0.13 m/s, and the maximum tension during pursing was 1,794 kgf. The best sinking performance was found in modified gear that used a 30.3 mm mesh knotless polyester net. The maximum depth reached by the net was 38 m, and mean sinking speed was 0.16 m/s at the middle position of the leadline. The maximum tension during pursing was 1,044 kgf. Independent sample t-test results show that the mean sinking depth and sinking speed in the simulated and measured results did not differ (P > 0.05). These results are expected to improve the efficiency and selectivity of small-scale purse seine gear.

• The Journal of Fisheries Business Administration
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• v.50 no.4
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• pp.29-44
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• 2019

This paper examines the trend of restructuring and direction of management response in the Large Purse Seine Fishery. The large-scale fishing industry is one of the most popular fishing areas in the coastal area, and it has been developed by providing exclusive supplies of many types of catchy fish, such as mackerel and horse mackerel through physical productivity in fleet operations. However, the Large Purse Seine Fishery has been declining in profitability due to the deterioration of the business environment since 2000. It is at a crossroads whether it will disappear or regenerate as it is. The Large Purse Seine Fishery's current problems are: firstly, the continued deterioration of the fishery business balance and worsening labor problems, secondly, insufficient freshness management and quality control after landing, and thirdly, import competition. The fourth is the intensification of the market competition, which is the evolution of fishing variability and the increase in the proportion of small fish. The fifth is the reduction of the operating fishing ground due to the suspension of mutual fishing in Korea and Japan. To address these problems and suggest management response directions for the survival of large-scale fishing businesses is as follows. First, a sustainable production system should be established through strengthening resource management and promoting international fisheries cooperation. Second, the profitability of fishing management should be improved by introducing a low-cost supplier system and securing a stable labor force. Third, we should improve the leading and quality control of catch, improve the high value-added value of catch through brand development, and secure competitive advantage with imported produce. Finally, the government should establish a cooperative system among private sector, government, and research institutes to push ahead with these tasks and strengthen the competitiveness of the front and rear industries.

• The Journal of Fisheries Business Administration
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• v.29 no.2
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• pp.163-175
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• 1998

The decrease of the fishery's business performance is due to the changes of environment-the increase of cost, the reduction of resources, the liberalization of import, the effectuation of the admiralty law Though the government has prepared the alternative policy to strengthen the competitive power of the fishery, fishermen should draw up a plan to improve the business performance. The problems of the small powered purse seine resulting from the small scale of the fishing boat is following. First, its catching activity in the sea is riskful. Second, the space to eat and to work is not enough. Third, the space to put the fish is not enough, it is hard to maintain the freshness of the fish. Therefore it is necessary to solve these problems for the scale of the fishing boat to have to be enlarged. The enlargement of the fishing boat to be required much expenditure of fund is the important investment decision to fishermen. The alternatives evaluation between the existing boat(defender) and the new boat enlarged with the new equipment(challenger) is necessary process to reduce the uncertainty of investment. The profitability of the challenger is better than that of defender due to the reduction of cost and the increase of revenue. Because the net present value of incremental cash flow is positive, it is rational for fishermen to accept the challenger.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.2
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• pp.93-101
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• 1999

A simple experimental method was used in an attempt to realize the elevation of the fishing ability of purse seine in the sea area of Cheju Island, the changes of seine volume and tension in the purseline during pursing. Experiments carried out on the six types simplified reduced model seines which were made of knotless nettings. The nettings were woven in different leg length 4.3, 5.0, 5.5, 6.0, 6.6 and 7.7mm of polyester 28 tex two threads two-ply twine, and each of the seines were named I, II, III, IV, V and Ⅵ seine. Dimension of seine models were 450cm for corkline and 85cmfor seine depth, each seines rigged up 160g of float for a floatline and 50g (underwater weight) of lead for a leadline. These model purse seines were made of the scale of 1/200 of its full scale, a 120 ton in the near sea of Cheju Island. Designing and testing for the model purse seines were based on the Tauti's law. Experiments were measured in the observation channel of a flume tank at the static conditions set up shooting and pursing equipments. Motion of purse seine during purse line was recorded by the two sets video camera for VTR which were placed in top and front of the model seine. The reading coordinate of seine volume carried out by the video digitization system, disk data for the purseline tension. An analysis were performed on the changes seine volume and tension in the purseline during pursing. The results obtained were as follows: 1. The seine volume during pursing was largest for Ⅵ seine with smallest d/l followed by V, IV, III, II and I seines, and tension in the purseline was small. 2. Seine volume during pursing can be expressed by the following equation; CVt=l-EXP[｛2.79 (d/l）＋0.35｝t-33.37 (d/l) ＋ 0.57] Where CVt is volume ratio, d is twine diameter, l is leg length and t is pursing time (sec). 3. Tension in the purse line during pursing can be expressed by the following equation; T= 1- EXP ｛0.57t ＋ 13.36 (d/l)+2.97｝ Where T is tension (kg) in the purseline during pursing.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.326-336
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• 2003

In order to modify the construction of gizzard shad coastal purse seine net with possible to the laborsaving of fishing operation in the coastal small fishing vessels, the model experiments were carried out on the model nets for several conventional nets using in the field and the experimental nets was manufactured as 1/100 and 1/60 of the full scale net. The results obtained are summarized as follows；1. In the case of the conventional net and reduction rate 75% in conventional net with purse line the fishing efficiency decreased, the lead line was upward for the surface and the pursing depth of pursing line was very shallow to 2∼3m. 2. In the case of the net having maximum depth in center part designed in this study, the length of float and lead line was 60% of conventional net, the depth of net was fixed 20m to selvage line of the both of the end and extend gradually with 50m, 40m, 30m to the center. Among the these net, depth of pursing line was 20∼23m for 50m and 7∼15m for 40m, 30m the depth of net. These results were suitable for interception of fish school in fishing ground, but several problems will be caused by the depth and current of fishing ground.