• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.4
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• pp.374-383
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• 2020

At ship design stage, the maneuverability is generally estimated based on the empirical formula or the computational fluid dynamic (CFD), which is one of the numerical simulation methods. Using the hydrodynamic derivatives derived through these methods can quantitatively estimate the maneuverability of target vessels and evaluate indirect maneuverability. Nevertheless, research on estimating maneuverability is insufficient for ships not subject to IMO maneuverability standard, especially fishing vessels, and even at the design stage, the empirical formula developed for merchant ships is applied without modification. An estimation error may occur due to the empirical formula derived from the regression analysis results of a model test if the empirical formula developed for merchant ships with different hull shapes is applied to fishing vessels without any modification. In this study, the modified empirical formula that can more accurately estimate the fishing vessel's maneuverability was derived by including the hull shape parameter of target fishing trawlers in the regression analysis process that derives Kijima et al. (1990) formula. As a result, the modified empirical formula showed an average estimation error of 6%, and the result improved the average error of 49% of Kijima et al. (1990) formula developed for merchant ships.

• The Journal of Fisheries Business Administration
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• v.35 no.2
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• pp.91-115
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• 2004

The main purpose of this study is to analyze the cooperative squid fisheries problems surrounding the $E128^{\circ}$, established by the 1965 Korea - Japan Fisheries Agreement which banned Korean large trawlers' fishing east to the $E128^{\circ}$ In fact, the moratorium was put on by Japans request. However, such issue did not occur until the filefish stock in the southern Korean sea, which was a major target fish species of the large trawl fisheries, The filefish stock collapsed completely around 1991 and at the same time most of bottom fish stocks in the East China Sea began to show a symptom of over - exploitation. Thus, the off - shore large trawlers learned to have a little opportunity of finding out alternative fish stocks as well as fishing grounds. Fortunately, at that time squid resource stock and consumption were on the increasing trend. The large trawl fisheries were able to economically exploit squid stock east to the $E128^{\circ}$ through cooperative fishing with squid angling light boats in the East and East - South Sea, even though such cooperative fishing activities violate the existing fishery laws apparently. Some important reasons that the large trawlers have continued the cooperative fishing seem to be because (ⅰ) squid resource stock has been on the increasing state over time, (ⅱ) the trawl fisheries have made a significant contribution to meeting domestic and export demands and stabilizing squid prices, and (ⅲ) they have kept domestic squid market from foreign competition. However, the new Korea - Japan fisheries agreement in 1998 provided a momentum of questioning the effectiveness of the $E128^{\circ}$ by the squid - related fisheries other than the squid angling. Serious conflicts between squid - related fisheries began to emerge and to be much intensified. Squid angling industries in the East opposed to large trawlers's efforts to formalize such illegal cooperative squid fishing activities. Their main argument was that such formalizing would definitely make the East coast squid prices lower and in turn their business performance would be worse off. The results of quantitative analysis suggest that the trawlers' massive landing may have a significant influence on lowering the east coast squid prices. Now, an important issue that the squid - related fisheries and the government are facing is to solve such complex squid fishing problems through a multi - participatory negotiation process, including price stabilization, total allowable catch level and its operation schemes, $E128^{\circ}$ rearrangement, and so on.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.2
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• pp.141-148
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• 2016

Annual and monthly pollock catches, CPUE and fishing grounds in the high seas of Bering Sea between 1984 and 1992 were analyzed for centroid distribution and bivariate ellipses of trawlers of South Korea, Japan, Poland and China. The catch amount differed by country as 56.1%, 21.7%, 20.4% and 1.8% were caught by Japan, Korea, Poland and China respectively. Japan recorded the highest mean CPUE at 5.7 ton/hour while it was 4.3 ton/hour for Poland, 3.9 ton/hour for Korea and 2.4 ton/hour for China. Cumulative catch varied by month, with the minimum of 137,000 ton in March and the maximum of 848,000 ton in December. Monthly mean of CPUE was the lowest in February (2.0 ton/hour) and the highest in November (6.3 ton/hour). The centroid distribution of monthly fishing ground was located at a southern spot ($56^{\circ}$ 05'N, $178^{\circ}$ 55'E) in January, and it moved anti-clockwise toward $56^{\circ}$ 37'N, $178^{\circ}$ 24'E in December. Fishing grounds were scattered more by the east-west direction than by the south-north direction. The fishing grounds were similar for Korean, Japanese and Polish trawlers, but Chinese trawlers that fished only from July to December showed distinctively different fishing grounds from the others.

• Journal of Fisheries and Marine Sciences Education
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• v.6 no.1
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• pp.11-19
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• 1994

The North Pacific midwater trawling which is one of the important fishing methods for Korean fishing industry is working in the Bering Sea and the sea near Kamchaka Peninsula. The catch by Korean midwater trawlers had been recorded about 300 thousands $^{M/_T}$ a year. Six types of midwater trawl net-ordinary midwater trawl net, super-V trawl net, super mesh trawl net, rope trawl net, super plus trawl net and kite trawl net-have been widely used by large trawlers above 1,500gt in size since 1982. Regarding the fishing efficiency, the super plus trawl net and kite trawl net were acknowledged as higher than other nets. Maximum mesh size of super-plus trawl net and kite trawl net ranges about 20m, whereas the length of net about 150m, and high-tech polyethylene is used as the material of rope part. The problems involved in the North Pacific midwater trawl net may be summarized as follows ; (1) The dimension of fishing gear is too big compared with the towing power of trawler. (2) The mesh size of the rope part is too big compared with that of the common netting part. (3) The net is often torn out in the connecting position of the rope part and the netting part. (4) The net is not matched with the trawler and the otter board in many trawlers, so the shape of the trawl gear in the water is instable. (5) The fish school located near head rope, ground rope and side rope in the net recorder is not caught in practice because of the net instability.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.5
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• pp.499-505
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• 2011

The fishing grounds of Korean large-pair trawlers have shifted since exclusive economic zones (EEZs) were established in a fisheries agreement involving countries neighboring Korean waters. The distributions of marine ecosystems and fisheries resources have been changing with environmental changes such as global warming and with the shift in species targeted as a result of changes in fishing technology and fishing gear. This study analyzed variation in the species assemblages caught in Korean waters by large-pair trawlers as a result of these geopolitical and environmental changes. The data used in this study were obtained from the Fishery Production Statistics of Korea and the Port Sample Survey of the National Fisheries Research and Development Institute (NFRDI) from 1990 to 2007. Hierarchical clustering analysis (HCA) and correspondence analysis (CA) were used to explore the characteristics of the catch-species composition. The overall variation in the species composition of the catch of Korean large-pair trawlers showed that the proportions of croaker Johnius grypotus, small yellow croaker Larimichthys polyactis, eel Anguilla japonica, and blue crab Portunus trituberculatus decreased, whereas those of hairtail Trichiurus lepturus, Spanish mackerel Scomberomorus niphonius, anchovy Engraulis japonicus, and common squid Todarodes pacificus increased in Korean waters over the 18-year period. The results of the HCA of the annual catch data by species showed four different distributions of fish species according to year. Results of the CA showed that the species assemblages differed between the 1990s and 2000s.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.13 no.2
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• pp.27-32
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• 1977

The paper deals the fishing condition of the stern trawlers operated in the Atlantic coast of Africa. The datas are gathered from the Korean stern trawlers operated in the area from June, 1975 to May, 1976. The obtained results are summarized as follows: 1. The mean catch per haul are calculated as, cuttle fish 14.5kg, large size squid(more than :lOOg of body weight) 28.2kg, small size squid(less than 300g) 36.4kg, octopus 47.0kg. 2. Small size cuttle fish(less than5OOg of body weight) are caught much during after spring tide in July to September, yet, large size ClIttle fish(more than 500g) are caught much during neap tide in October to January. 3. Small size squid(less than 300g of body weight) are cBught much during after spring tide in October to December, yet, large size squid(more than 3OOg) are caught much during before spring tide in October to March. 4. Octopus are caught during neap tide in July to August.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.2
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• pp.162-168
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• 2016

This study attempted to help determine Korean fishery policies by proposing improvement plans after examining the current regulations, fishing vessels, fishing gear and fishing methods of the middle sized trawl fishery in the East Sea for targeting only squid. In general, the size, engine horse power, and net length of the middle sized trawlers are between 50 and 60 GT, 1,200 and 1,600 PS, and approximately 165 m with four seamed trawl nets, respectively. While a jigging vessel attracted squids using lights, the trawler approached a jigging vessel. The trawler let the jigging vessel know its decision for fishing, and then jigging vessel rolled up jigs. The net of the trawler was casted at 45 degrees between the bow and the stern of the jigging vessel. Once the trawler towed close to the stern of the jigging vessel upon its passing of the jigging vessel, the bow of the trawler turned 45 degrees left again. Then, squid aggregations were entered into the net. When the cod end was passed a light vessel, the trawler hoisted the net up to the otter board. Then the trawler turned 180 degrees. It repeated three to five times of fishing operations as the previous method. We recommend that the regulations allow nineteen side trawlers to catch like stern trawler, as well as the cooperative trawler and jigging vessel operations.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.3
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• pp.311-326
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• 2013

For providing a basic data concerning with a fishing deck layout design of a trawler the authors conducted the video observations about the working activities of crews on the deck in the different layout of two Korean coastal large stern trawlers (gross tonnage: 139). The winch of the trawler-A was installed on the aft of the fishing deck and the trawler-B, on the forward of the fishing deck. The work and activities of the deck hands on both trawlers were observed using the CCD (charge coupled device) camera installed on each trawler's deck for one month from August 3, 2010. The video data was analyzed by the hierarchical task analysis (HTA) method. In results, numbers of tasks to require deck hands during the hauling net and the casting net were 25 and 28 for the trawler-A and 27 and 48 for the trawler-B, respectively. The working processes were represented a same in both of the trawlers. Location for controlling the deck machineries, the location installed trawl winch, kinds of deck machineries, crew's custom for using deck machineries were the factor affecting to the number of the task. In the case of the improvement suggested in the results is carried out, the reduction percentages of the number of task in the trawler-A and trawler-B were estimated as 24.5% and 51.3%, respectively. Through this study it was found that the quantitative analysis is possible for the work processes, work methods and the work contents in the trawler. Also the suggestion for improving the fishing deck layout design of the trawler was possible by finding out the factors increasing the number of tasks and removing the tasks. We expect that the results of this paper are used as a basic data for designing the layout of deck machineries in the trawler in the future.

• Asian Journal of Business Environment
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• v.11 no.2
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• pp.5-13
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• 2021

Purpose: This paper aims to study the fishing capacity of the shrimp trawlers in the Aru and Arafura Sea. Research design, data and Methodology: The abundant shrimp resources call for its sustainable use to advance economic activity. Time-series data of effort and catch from shrimp trawlers from 1980-2015 were utilized. The technical efficiencies of the vessels and the target capacity of the shrimp fishery were estimated using Peak to Peak Method. Results: Arafura's shrimp fishery presents high technical efficiency, which is suggested by the high scores of its fishing capacity utilization. The issuance of a ministerial decree on the prohibition of the use of trawls has impacted the plummeting of Arafura's shrimp trawler production right after the regulation implemented in 2015, which is far below the total production of the Arafura's shrimp trawler in 1980. Today, the Aru and Arafura Sea has different sets of fishing gears that are dominated by Squid Jigging and gillnet vessels. Conclusions: Arafura shrimp fishery performs high technical efficiency, which is indicated by the high utilization value of its catching capacity ranging from 71% to 100% annually from 1980 to 2015 This has shown that the resource-utilization has shifted from shrimps to other economically important species during the post trawl ban such as squid and pelagic. Any future intention to utilize shrimp resources, interaction of gears harvesting shrimp with current gears should be well considered in the policy making process.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.7 no.1
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• pp.39-43
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• 1971

Koreans have been interested in the North Pacific fisheries since the exploratory fishing was carried out by R/V Baek-Kyung of Pusan Fisheries College in 1966. Although the salmon fishing was interrupted by some countries, Korean trawlers are venturing in the North Pacific Ocean for catching demersal fishes. The trawl fishery in the region raises some problems. i. e. the conflict with the coastal or nearshore fishery, low fish price, etc. This paper concerns with the plan for the settlement of these problems..