• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.4
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• pp.211-222
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• 2009

The fisheries resources by a set net in the coastal waters off Neungpo, Goeje Island from 2003 to 2004 were studied to determine species composition and catch variation. The main fishing period by a set net were from April to December in 2003 and from May to December in 2004. A total weight of 48 species caught through the survey period was 540,688.0kg. Most of them were 44 species of fishes and a few were 4 species of cephalopods. Dominant species was Trachurus japonicus accounting to 57.5% in total catch. Sub-dominant species were Trichiurus lepturus(12.9%), Engraulis japonicus(10.6%), Scomber japonicus(6.9%), Clupea pallasii(4.5%), Todarodes pacificus(2.8%) and Parapristipoma trilineaturm(1.3%). The remnant species showed a low catch, indicating the catch had less than 1% in total, respectively. T. japonicus and T. lepturus were caught throughout the survey period, but C. pallasii, Gadus macrocephalus, Oncorhynchus keta in low temperature season and Thunnus obesus in high temperature season. The fishing ground temperature was 11.7-24.0${^{\circ}C}$ in range and the catch by a set net was higher in autumn than in spring and in summer with the variation of fishing ground temperature. The annual catch by a set net was much higher in 2004 than in 2003 due to high temperature(>17${^{\circ}C}$) and the recruitment of T. japonicus from offshore seas. Therefore we concluded that the catch of Neungpo fishing ground by a set net was highly related to the variation of T. japonicus catch with fishing ground temperature.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.24 no.4
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• pp.150-157
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• 1988

The oceanographic condition around the set net fishing ground in Yeosu Bay was investigated by the oceanographic observation in June, July and August, 1988. Also the catch of the set net was analized by daly catch data of the three set net fishing ground from April to September, 1988. The results obtained are as follows: 1) The coastal surface water is high temperature and low salinity through the influence of land, and the off shore water and bottom water are low temperature and high salinity. 2) The eddy current and the sharp thermocline in June appeared in August at the set net fishing ground, and a good catch appeared in June and August. 3) The surface temperature and salinity at the set net fishing ground are 11$^{\circ}C$ to 27$^{\circ}C$ and 31.60$\textperthousand$ to 34.80$\textperthousand$. The surface temperature and salinity of a maximum good catch are 21$^{\circ}C$ and 33.80$\textperthousand$ to 33.99$\textperthousand$ respectively. 4) The dominant species of fish were spanish mackerel, scad, anchovy, sardine, common mackerel, hairtail, crab, yellow tail, in order of catch.

• The Journal of Fisheries Business Administration
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• v.51 no.4
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• pp.19-45
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• 2020

This study is to evaluate economic effect of the creation project of snow crab, Chionoecetes opilio, spawning and habitat ground in Uljin and Youngdeok county. The main results of this study are summarized as follows: first, 14,400 million won was invested in the creation project cost of Chionoecetes opilio spawning and habitat ground of Uljin and Youngdeok County from 2015 to 2020. Second, the creation project of Chionoecetes opilio spawning and habitat ground directly provides fishing benefits, festival benefits, research and development benefits and employment benefits. Third, on the basis of above benefits, the creation project of Chionoecetes opilio spawning and habitat ground has net present value of 29,900.53 million won, internal rate of return 16.9%, and benefit-cost of 2.91 under a 4.5% social discount rate. Also, the creation project creates 195 jobs. This indicates that the creation project of Chionoecetes opilio spawning and habitat ground not only contributes to the increase in the income of coastal fishery and fishing villages but also to the job making. The result of this study provides useful information to policy makers or project managers as it shows that the project to create spawning and habitat ground should be carried out in consideration of the resource and biological characteristics of individual fish and that economic assessment logic should also be developed based on this. Also, it proves that the project to create a snow crab spawning and habitat ground is a national and local infrastructure project that increases the actual fishing income in the region. At the same time, it maintains the reproducibility function of most fish species, along with enhancing the people's benefits such as fishing village tourism and marine product consumption. Moreover, it provides useful information on budgeting for the continuous development of snow crab spawning and habitat ground in the mid to long-term.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.2
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• pp.152-161
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• 2019

This research carried out a study on the job characteristics of the skipper of the coastal composite fishing vessels in order to find a way to prevent the ship collision caused by the highest human error among the marine casualty of fishing boats. Video observation was used as the research method in which six CCD cameras were installed on the vessel to collect image data and data extracted from the image were analyzed to derive the results of the functional activity of skipper according to the fishing operation process of experimental fishing vessel. The results are as follows. The working process of the experimental fishing vessel consisted of navigation for fishing ground, setting line, waiting for hauling line, hauling line and navigation to homeport. In these processes, the skipper was performing watchkeeping in the wheelhouse in which he carried out a single task, a dual task that performed two tasks simultaneously, and a triple task that performed two or more tasks simultaneously. In addition, one of the risk factors causing the collision was a no watchkeeping in the wheelhouse for navigating for fishing ground, waiting for hauling line, and hauling line at 25.4%, 64.6% and 0.3%, respectively among the marine casualty while drowsiness caused 1.2% of the marine casualty in navigating for fishing ground. Concurrent tasks that simultaneously perform two or more tasks that can overlook any other important duties while carrying out watchkeeping in the wheelhouse include 51.3% of navigation for fishing ground, 81.9% of setting line, 19.0% of waiting for hauling line, 87.9% of hauling, and 88.7% of navigation to homeport. The above concurrent tasks yielded an average of 66.1%. Experimental fishing vessels are required to focus on ship handling operations related to fishery operations, and the skipper is assigned more activities and attention to fishery related tasks. Therefore, it is considered desirable to build a collision prevention system that is appropriate to the characteristics of the skipper's work, escaping from transferring the responsibility of ship collision to the skipper completely.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.2
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• pp.157-163
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• 2018

In the area around Jeju Island, the squid jigging fishery and the hair-tail angling are popular. Therefore, the study on the characteristics of the formation and shift of fishing grounds is very important. We have received and analyzed AIS data of all vessels around Jeju Island from October 16, 2016 to October 16, 2017, and extracted the positions of the fishing vessels with the same operational characteristics as the fishing vessels of their fisheries. The distribution chart of the frequency of fishing vessels appearing in each predefined fishing grid ($1NM{\times}1NM$) was analyzed. So we took a analogy with the monthly shift of fishing grounds. Many fishing vessels appeared in the seas around Jeju Island from November 2016 to January 2017, and the frequency of their appearance was maintained. In November, however, fishing vessels were mostly concentrated in coastal waters. Yet, the density gradually weakened as they moved into January. From February, the frequency itself began to decline, making it the worst in April. The high concentration of fishing vessels in the waters leading from Jeju Island's northwest coast to south coast in November is believed to be related to the yellowtail fishery that are formed annually in the coastal waters off the island of Marado. In May 2017, the appearance frequency of fishing vessels increased and began to show a concentration in coastal waters around Jeju Island. Fishing vessels began to flock in waters northwest of Jeju Island beginning in July and peaked in August, and by September, fishing vessels were moving south along the coast of Jeju Island, weakening the density and spreading out. Between July and August, fishing vessels were concentrated in waters surrounding Jeju Island, which is believed to be related to the operations of fishing vessels for the squid jigging fishery and the hair-tail angling.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.2
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• pp.138-144
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• 2019

The purpose of this paper is to explore the fishing grounds of trawl fishery, which are operating in the waters around Jeju Island, and to investigate the monthly shifting changes of the explored fishing grounds. Information on AIS of fishing vessels operating near Jeju Island was collected and analyzed from October 16, 2016 to October 16, 2017. Thus, the location of fishing vessels with the same operational characteristics as those in this industry was extracted and displayed on Google Maps' location drawings to analyze the dense distribution of fishing vessels according to the frequency of their appearance. In the distribution of fishing vessels that appeared in October, a wide range of fishing grounds connecting the upper and lower waters of the 221 and 222 sea of fishing area was found to have gradually expanded and increased density, showing the widest range and highest density in December, and then gradually decreasing from January 2017 to near extinction in May. The distribution of fishing vessels that appeared in the left and lower waters of the 243 sea estuary increased not only in November and December, but also in the appearing sea areas gradually moved to the 242 sea and the range of their appearance was extended to the 241 sea. In other words, the highly dense fishing area in December indirectly shows that it is winter fishing grounds for these industries. The distribution of these dense fishing vessels gradually moved north and west with each passing day, reducing their density and reaching a near extinction in August. However, in September, the density was gradually restored again. Fishing vessels that appeared in high density in the northern waters of the 224 sea east of the Yeoseo island in December were thought to be fishing vessels, whose density decreased over time, almost disappeared in May, and reappeared in July and August, showing a certain degree of density, and then decreased again.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.3
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• pp.179-185
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• 2006

In order to efficiently manage the coastal and offshore fishing ground, the applicability of real-time monitering was also investigated through a wide-area network of automatic identification system(AIS). The experiment of efficiently managing coastal and offshore fishing ground with a wide-area network of AIS required, on the headquarter's screen, a synthetic display of vessel information transmitted from three different distant stations. This experiment tested the applicability of real-time monitoring with the shown display. The maximum range of detection of the first station in Busan was 24 nautical miles while those of the second and third stations in Yeosu and Jeju were 26 and 52 nautical miles, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.1
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• pp.1-8
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• 2023

In this study, the stability of fishing boat inducing the change of fishing lamp in accordance with the installation of induction lamp in comparison with metal halide lamp was investigated. Inclining test for 8.55 ton class of hair-tail angling fishing boat was performed in order to find a GM and light weight. A stability calculation of the target fishing boat on the basis of KST-SHIP program was evaluated. The stability of the fishing boat with a metal halide lamp such as induction lamp according to the result obtained by the inclining test is slightly different, and the stability is not so much affected. Due to the induction lamp installation, the wind area increased by about 3.178 m². Before installing the induction fishing lamp, G₀M was found to be 0.209 at full load departure and 0.296 at departure from fishing ground. After installing the induction lamp, the full load departure condition is 0.178 and the fishing ground departure condition is 0.260. The G₀M value before and after installation of the induction fishing lamp shows a difference of about 3% at the full load departure condition. The value of the critical angle of inclination definition showed a difference of about 16%. Despite these differences, it is lower than the regulations; it was confirmed that there will be no significant difference unless it is in an overloaded state.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.6
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• pp.413-424
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• 2005

The study focused on the fluctuation of the fisheries conditions in fishing ground of yellow croaker, Pseudosciaena polyactis Bleeker. A long-term decreasing trend was observed in the accumulated catches of the species since 1926, with increasing-decreasing fluctuation repeating 6 times. Periodicity was observed in 10-year interval in good fishing years, but not in poor fishing years which had irregular fluctuations. From the geographical distribution of the past catch per unit effort, it was presumed that a group of the species seasonally migrated but most of the groups stayed throughout year in the western area off Cheju Island, which was different from the assumptions of the 1970's. The fishing grounds were distributed along the migration route differently by season, throughout the Yellow Sea and the East China Sea, but shifted gradually southward and narrowed down to the area of $32^{\circ}N-125^{\circ}E$ off Cheju Island, where the center of fishing grounds was given birth to throughout the year with a relatively high density from autumn to spring. It was noted that a negative correlation was shown between the area of fishing grounds and density distribution of catch.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.3
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• pp.249-256
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• 1996

The saury stick - held dip net fishery of Korea in the Northwest Pacific Ocean began in 1985 with 3 vessels. Since then the fishery has grown so rapidly year by year that the number of vessels increased to 34 and the catch to 40 thousands Mff in 1993. In the present study, the monthly situation and the movement of the fishing ground for the pacific saury in the Northwest Pacific were investigated and the monthly optimum fIshing tempertures were estimated, from the relationship between the catch and the sea surface temperature. In the beginning of the fishing season, June to August, the fIshing ground is formed in the very wide range, mainly in the northward area of the front meandering, as the parcific saury migrate northward. In the main season, September to November, the ground is formed in the southward area of the front, off the east coast of Japan. Andd then, the fishing season ends in December with the ground coming near to the east coast of Japan. The monthly optimum fishing tempertures showed 11~$13^{\circ}C.$ in June to July, 13-$17^{\circ}C.$ in August to November, and 15~ $17^{\circ}C.$ in December in general. The profIles of water temperature were much different in accordance by net casting position in the fishing ground, regardless of season. So, the MLD and CPUE was analyzed to find out the relation between the water temperature and the catch. Then, it is found that the CPUE shows over 0.7Mtr/haul as the MLD 40~70m.40~70m.