• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.25 no.2
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• pp.54-60
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• 1989

This paper described on the tracking of an individual fish at the fishing ground of set net by use of a small ultrasonic fish tag. The apparatuses used were composed with a tag, three receivers and two time-interval counter oscilloscope. A pulsed ultrasonic transmitter tag fitted to back of a dorsal fin of a yellowtail specimen, Seriola quinqueradidta TEMMINCK et SCHLEGEL is tracked by measuring differences in the time of arrival of the acoustic pulses at an arrangement of three receivers in the freeding tank. The successive positions of the fish were calculated from the differences in the received time of the signals. A fish carying the tag was tracked in the fishing ground of set net by use of the hydrophone and Loran-C. The results of the tests showed that this method gave good positional information to track the movement of an individual fish in the fishing ground of set net.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.695-702
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• 2009

This study includes spatial variations in the catch of billfishes in the Pacific Ocean and examines factors affecting interannual changes in the catch. Main billfish species caught by Korean tuna longline fishery were blue marlin and swordfish. A main fishing ground of the species was the tropical Pacific Ocean, while additional fishing ground of billfishes tended to be formed in the Pacific coast of Mexico in the El Nino periods. Further, the catch of billfishes was significantly related to CPUE (tons/average of the used hooks/vessel) in the entire Pacific Ocean as an index of stock abundance and equatorial SOI (EQSOI) as an index of El Nino event. Annual changes in the catch of billfishes in the Pacific Ocean could be regulated mainly by variations of stock abundance. In addition, increase of the density of billfishes in the tropical Pacific and additional formation of fishing ground by El Nino event possibly contribute to increase of the catch of billfishes in the Pacific Ocean. On the other hand, linear regression model may be more adequate in the analysis of relationships between fisheries data and indices made from using some environmental factors.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.6
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• pp.451-457
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• 2011

Large scale fishing ground can be made by upwelling flow. Recently the fishing ground development projects, using artificial upwelling by large structure under the sea, are in progress in Japan and Korea. In this study upwelling flow is simulated with FLOW-3D model. Using the movement of marker in FLOW-3D, the method for simulating upwelling of nutrients was experimented. The results show that FLOW-3D model can evaluate upwelling effect before starting real project.

• Journal of Ocean Engineering and Technology
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• v.15 no.1
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• pp.36-44
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• 2001

To predict the influence on fish stocks which were caused by environmental change in the fishing ground of shallow sea areas, we have developed the Shallow-Sea Ecological Model(SSEM) which that focuses on living organisms, especially fish and benthos. By applying the SSEM in the Seto-Inland Sea of Japan, we have simulated another aspect of influence on fish stocks that was caused by oxygen deficient water mass and nutrient loads. From the simulated result of the fish stocks, it was indicated that the stock of fish and benthos has shown a relative difference between the western sea and the eastern sea in the Seto-Inland Sea. According the to prediction, results of fish stocks that were caused by oxygen deficient water mass, it was estimated that the pelagicfish stock increases about 6 %, whereas the stocks of demersalfish and benthos decreases about 30% and 70%, respectively. On the other hand, it seemed that there was an increased in the fish stocks of demersalfish and benthos in the eastern sea of Seto-Inland Sea by nutrient loads reduction.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.4
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• pp.356-362
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• 2019

We collected AIS information on fishing vessels operating near Jeju Island, and analyzed appearance density of the Chinese fishing vessels and inferred the movements of the fishing grounds. AIS information was received from October 16, 2016 to October 16, 2017 and stored on a hard disk through a program called AisDecoder. Unauthorized fishing vessels within the Exclusive Fisheries Agreement Zone (EFAZ) operated near the EFAZ boundary, and the frequency of appearance of fishing vessels were high in the middle waters of Korea and Japan, 252 and 250 fishing zones. Chinese fishing vessels authorized to enter appeared scattered outside the Prohibiting Fishing Zone of the Large Trawlers (PFZLT), and the closer they were to the PFZLT boundary, the higher the appearance density. And the appearance of Chinese fishing vessels with a speed from 0 to 3 knots was mostly outside the EFAZ, showing high density in the waters close to the boundary between Korea and Japan. On the other hand, within the EFAZ, the frequency of appearance of Chinese fishing vessels was also low and scattered. The appearance of Chinese fishing vessels with a speed from 3 to 5 knots mostly shows some variability within the EFAZ, but the frequency of appearance was high and the density was high. The seasonal appearance of Chinese fishing vessels in the waters south of Jeju Island appeared in the southwest in the autumn and then moved south and southeast of Jeju Island in the winter, and in the spring and summer. They were considered going to other fishing grounds without fishing in the waters south of Jeju Island.

• The Journal of Fisheries Business Administration
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• v.27 no.2
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• pp.51-63
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• 1996

This study is concerned with the identification of the concepts and characteristics of the traditional access of small scale fishery and traditional small scale fishery based on the classification of fisheries under Fisheries Law, As we called, these fisheries are the small scale of artisanal fisheries. These traditional small scale of artisanal fisheries have been developed throughout the most coastal fisheries but have never been included the institutional fishery system and policy since industrial fisheries have been exploited. By this reason there was no studies to understand and identify these fisheries as fisheries under category of institutional fishery system. Recently by the Fisheries Law, my Person who desires to operate these fisheries, shall report to the provincial governor and then these fisheries were incorporated into the category of fisheries to be reported. But this case of the administrative practices should be not consistent with the classification of fisheries under Fisheries Law. The traditional access of small scale fishery is a derivative concept of fishery categories under the institutional fakery system Because this fishery under institutional fishery system can not be establish the right of fishing by fishery right system technically but the right of fishing is supported by the fishing access system only. Therefore, It is a mistake for the provincial fishery governor to adopt such a policy that the fishing right of the traditional access of small scale fishery which is different from the fishing based right is restricted by the factors of fisheries to be reported. On the other hand the traditional small scale fishery is coincident with the traditional access of small scale fishery and the common fishery under the style of utilization of fishing gear and fishing gear and methods. But this fishery has never been included the fishery categories supported by the government subsidy policies and considerations and has been remained with indifference during the last few decades. Anyhow the fishing right of these fisheries have been assured under the institutional fishery system, any person who desires to operate this fishery should have a fishing right against the public or private uses of fishing ground such as land reclamations and other coastal zone development. A deprivation of the fishing right of this fishery by the conflicts of these public and private uses of fishing ground is not regarded as appropriate according to the social welfare policy. Also it is the administrative expediency to support the fishing right of this fishery under the fisheries lobe reported.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.3
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• pp.176-182
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• 2007

Fishing power, which means performance of fishing vessel or catchability of fishing gear, can explain using by fishing power index(FPI) to compare fishery efficiency among uniformity types of fishery that work during the fixed period in specific fishing ground. This research analyzed on their fishing power and catchability using comparing each sampled vessels of coastal trap fishery for common octopus. The results showed that they were no difference in amount of used trap and immersed time etc. in CPUE among sampled vessels, and had no correlation of catch production due to vessel's tonnage. Most vessel's FPI estimates but 3 vessels were higher than the averaged, and showed similar fishing power in general. And then, CPUE and FPI showed that 4 to 5 tonnage vessels would be superior to another, 4 tonnage vessels had also good catchability. Therefore, we estimated that 4 tonnage vessels had the most efficiency work for coastal trap fishery for common octopus.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.4
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• pp.363-371
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• 2019

Thousands of demersal fishes inhabit in the waters around Korea and most of them are overexploited. One of 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 Danish seine fishery from 1960s to 2010s. Gross tonnage was decreased stably, but the horse power was increased annually. The length of ground rope, warp and hand rope was somewhat longer, but changed a little. Color fish finder was utilized from the mid-1960s and positioning system was used five years later. A hydraulic line hauler were introduced in the mid-1980s, and supply rate was gradually increased. Surveys on the supply and upgrading of fishing equipment utilized visiting researchers. Therefore, the relative fishing power index in the Danish seine fishery increased stably from 1.0 in 1970 to 1.0 in 1980, to 1.2 in 1990, to 1.3 in 2000 and to 1.3 in 2010. The results are expected to contribute to reasonable fisheries stock management.

• Journal of Environmental Science International
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• v.26 no.2
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• pp.173-181
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• 2017

Catch data for the common squid (Todarodes pacificus), classified by squid-jigging fisheries per grid (size: $0.5^{\circ}latitude{\times}0.5^{\circ}longitude$), and the water temperature values KODC (Korea Ocean Data Center) were collected for the 1980-2009 period to study the changes in squid distribution and migration with climate regimes (1980s, 1990s, and 2000s). The primary fishing period in the 1990s and 2000s was approximately 2-3 months earlier than that in the 1980s. Especially in the East Sea, the fishing grounds in the 1980s stayed longer at high latitudes than those in the other decades. Moreover, in the 1980s, centers of the fishing ground were located near the Yamato bank (central East Sea), whereas in the 1990s and 2000s, they were situated near the southeastern coast of the Korean peninsula.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.4
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• pp.238-246
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• 1991

In order to make clear the mechanism forming the fishing ground of anchovy drag net in connection with water temperature, catch and oceanographic data for the years of 1970-1988 in the Southern Sea of Korea were analyzed. The annual catch of anchovy drag net was about 21,000M/T in 1970 but it was increasing largely so far 100,000M/T in recent years. The fishing season of anchovy drag net is the whole year beside the prohibition season established in aims to protect the spawning group of anchovy, and then in the best season of the period from July to December, the fishing ground is made up in the coastal area joining Yosu, Namhaedo and Bangeojin. There were some evidences that the fishing condition was controlled by the oceanographic condition, especially water temperature, that is, when there was large difference in water temperature between the south area of the Eastern Sea and the west area of the southern Sea and the thermocline is formed strongly in the larger less than 20m, the fishing condition was good. On the other hand, there was a very effective correlation between the catch(X) of anchovy spawning group in Spring by other fishing gears, mainly drift net and that(Y) of the little size of anchovy by drag net in Autumn, expressed by the relative equation, Y=62,246+1.3X, r=0.63.