• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.4
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• pp.333-342
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• 2018

In order to manage and rebuild fishery resources, the fishing effort should be controlled effectively. Especially in the setting up of the proper level of fishing efforts, economic standards as well as biological standards must be carefully considered to promote the sustainable and economically viable development of fisheries. This study is aimed to estimate optimal fishing effort of giant octopus by combo fishing which uses longline in Gangwon with statistical data. The result showed that current fishing effort is 28% higher than $E_{MEY}$. Unit fishing cost for each voyage will be 27% lower and unit fishing profit will be 17% higher than the current situation when the fishing effort meets $E_{MEY}$. Although current fishing effort is similar to the $E_{MSY}$, current catching is 16% higher than MSY and 22% higher than MEY.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.787-797
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• 2021

Yellowtail Seriola quinqueradiata tagged with a Pop-up Satellite Archival Tag (PSAT) was released off the coast of near the Moseulpo, Jeju Island and the ecological data during about 40 days was obtained. However, it is difficult to determine the spatial location of underwater ecological data. To improve the accuracy of estimating the Yellowtail migration route using temperature, suitable background field of the oceanic environment data was evaluated and used for input data. After developing of the tracking algorithm for migration route estimation, three experiment cases were estimated with ecological data among the surface layer, the mixed layer, and the whole water column. All tracking experiments move from western to eastern Jeju Island. Additionally, tracking experiment using 3D ocean numerical model reveal that it is possible to estimate the migration route using the fish ecological data of the entire water column. Therefore, using a large number of ecological data and a high-accuracy ocean numerical model to estimate the migration route seems to be a way to increase the accuracy of the tracking experiment. Moreover, the tracking algorithm of this study can be applied to small pelagic fishery using small archival electronic tags to track the migration route.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.60 no.2
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• pp.101-113
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• 2024

This study investigated the species composition and community structure of aquatic organisms captured using coastal beam trawling in Gomso Bay, Jeollabuk-do, from January to December 2022. Throughout the experimental period, a total of 20,246 individuals belonging to 94 marine species were captured, with a combined biomass of 602,828 g. Fish exhibited the highest abundance, comprising 56 species, followed by crustacea (21 species), bivalvia (8 species), cephalopoda (5 species), gastropoda (3 species), and holothuroidea (1 species). The dominant species was Leiognathus nuchalis, constituting 14.0% of the total individuals, followed by Portunus trituberculatus at 12.1%, Oratosquilla oratoria at 10.4%, Crangon hakodatei at 9.9%, and Metapenaeus joyneri at 7.9%. The diversity index ranged from 1.72 to 2.55, with the lowest diversity observed in March and the highest in July. Cluster analysis based on species composition of the 27 most common species showed that aquatic organisms were divided into three groups: spring and summer organisms (Group A) and summer organisms (Group B) and autumn and winter organisms (Group C).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.229-232
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• 2022

Recently, production of offshore fisheries in Korea has been decreasing. Since production of offshore fisheries in 2016 fell below 1 million tons for the first time in 44 years, it has not recovered and has been decreasing. In order to cope with such a decrease in fishery resources, the TAC (total allowable catch) system is implemented internationally for fisheries resource management. Since 1999, South Korea has introduced the TAC system to perform resource management. In this paper, we propose an artificial intelligence-based fish classification and weight estimation system that can be used to investigate fishery resources of land observers essential for the implementation of the TAC system. The system consists of an app and a cloud server that automatically measures the body size and height of fish and takes photos using a terminal equipped with a lidar sensor. In the cloud server, fish classification is performed using a CNN-based efficientnet model and the weight of fish is predicted using automatically measured body length and body height information. Using this system, it is possible to improve the existing method in which the land observer manually writes after measuring the tape measure and weight in the stomach market.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.1
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• pp.60-68
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• 2024

The size distribution, maturation, and molting stages of the snow crab Chionoecetes opilio in the coastal sea of Gyeongbuk were investigated to understand its monthly and bathymetric occurrence patterns. C. opilio was collected from three depth strata (A1, 100-120 m; A2, 120-180 m; A3, 180-220 m) from May to November 2020. The average sex ratio was 0.8. The mean carapace width was largest in females in October, and in males in November. The occurrence rate of small immature crabs was the highest in A1. The ratio of ovigerous females at 75-80 mm was highest at A2 and A3. There was a significant difference in carapace width in females and depth in both sexes in September and October. The occurrence rate of immature crabs was the highest in A1, whereas that ovigerous and spawned females was higher in A2 and A3 than in A1. Very old-shelled females occurred highly in September and October. The occurrence rate of newly shelled males was higher throughout the study period. This research indicated that the size distribution, maturation conditions, and molting stages of C. opilio varied with water depth strata in the coastal sea of Gyeongbuk, Korea.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.69-70
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• 2002

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.3
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• pp.353-373
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• 2022

Many fish species are imported into Korea from various countries. However, in the case of some fish species, there are many that do not have Korean names. Species similar in morphology to domestically produced aquatic products are often disguised as being domestically produced and distributed. Therefore, this study presents a species list for 1,032 fish imported into Korea. Fish species that have not been given Korean names have been given a Korean name using a scientific method to prevent confusion during seafood distribution. Standards for naming stingrays, skates, and mackerel, which are often confused when a country name is being assigned are presented.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.568-573
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• 2021

A single leptocephalus specimen of Albula glossodonta belonging to the family Albulidae under the order Albuliformes, was collected from the southern sea of Korea in May 21, 2019. This species is distinguished from A. vulpes in the number of melanophores at the base of the caudal fin. In addition, our specimen was readily distinguished from A. argentea in having no melanophores on the operculum, at the base of the dorsal fin and in front of the pectoral fin. Also it was well distinguished from A. gilberti in having no melanophores on the operculum, in front of the pectoral fin and on the lateral body. A molecular analysis based on 467 bp sequences of the mitochondrial DNA 16S rRNA shows that the leptocephalus is well matched to A. glossodonta adult (K2P distance=0.002). We report the first occurrence of A. glossodonta leptocephalus in the Korean waters, and propose it's new Korean name, "Nam-bang-yeoeul-myeol".

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.3
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• pp.264-269
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• 2021

A single postlarva (9.72 mm in standard length) specimen of Crossorhombus azureus (Alcock, 1889) belonging to the family Bothidae, was collected using a bongo net from the southern sea of Korea on December 10, 2019. This species is characterized by having spines on post basipterygial processes. It has two eyes located at the opposite side in head, which accordingly belongs to pre-metamorphosis stage. Melanophores are distributed on the dorsal and anal fin base on the right side (blind side), which is regarded as a useful identification key distinguishing C. azureus from congeneric species in their postlarval stage. A molecular analysis based on mitochondrial DNA COI sequences showed that our specimen was closely matched to adult C. azureus (K2P distance = 0.017). As there is no Korean name for the genus Crossorhombus in spite of presence of Crossorhombus kobensis and its Korean name "Go-be-dung-geul-neob-chi" in Korea, we proposed a new Korean name "Dung-geul-neob-chi-sog" for the genus Crossorhombus and "Pa-lang-dung-geul-neob-chi" for the species C. azureus.

• The Journal of Fisheries Business Administration
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• v.39 no.1
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• pp.115-132
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• 2008

This study raises the question about why do many international fisheries organizations or regional fisheries agreements come into existence, sustain, and develop prior to the internationally recognized institution such as United Nations Convention on the Law of the Sea(UNCLOS). In oder to solve the problem, I will investigate the characteristics of fisheries as renewable resources and propose the collusion model where it is based on the cost-benefit analysis. Especially, if once a fooall large number of fishing is implemented, they are immediately depleted. Consequently they are extinct and no longer exploitable. Thus each interest nations or participants will be better off if they are cooperative and will be worse off if they are competitive or noncooperative in a resource management. Therefore, many of the internationally recognized fisheries institutions and agreements have been made and developed in these days.