• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.701-707
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• 2023

We investigated Euphausia pacifica population in Korean waters in 2016 By samplings for genetic structur at five stations. Three sampling stations were located in the middle of the water masses which were clustered by temperature and salinity whereas the other stations were at the boundaries of the water masses. We amplified a 566 bp region and compared it with sequences of E. pacifica distributed in other waters. Sequences were classified two clades, and a clade was formed in the station E. Genetic distance of station E was close to E. pacifica present in Bering Sea, while it was distant to E. pacifica present in Yellow Sea near China. In genetic analysis, seven haplotypes were formed. Hap-1 and Hap-2 were shared in all five stations, while Hap-3 was shared in station W and WS. Four independent haplotypes were present in station E. Haplotype and nucleotide diversity were the highest in station E and the lowest in station S. The F_ST distances between station E and other stations were the highest, but distances among other stations were low. As a result, we concluded that E. pacifica, which is distributed in Korean waters, has a genetic population differentiation in the East Sea (station E).

• Journal of Fisheries and Marine Sciences Education
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• v.9 no.2
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• pp.121-148
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• 1997

The Japanese fishery management system has been established on the basis of various experience accumulated over many years. The fishery management system in Japan, one of the oldest fishery management systems in the world, is aimed at ensuring comprehensive utilization of the water surface and developing fishery productivity, by giving protection of the breeding environment of aquatic animals and plants, enabling the appropriate use of fishery grounds, preventing and solving disputes over fishery grounds and making other fishery adjustments. Japanese Fishery Law has been changed largely into (1) The Feudal Era(to 1900), (2) The Oldest Fishey Law(1901~48), (3) Current Fishery Law(1949 to present). Japanese fishery legislation is designed as a single package combining coastal, offshore and distant-water fisheries. During the period of the old fishery law, numerous conflicts arose over the joint use of fishing grounds and fish stocks. Such conflicts occurred among users of the same gear as well as between users of different gears or of different sizes of fishing craft. Large scale conflict sometime occurred between neighbouring fishing communities due to a lack of fairness in principle and coordination in practice. Therefore, the new fishery law enacted in 1949. This law was designed primarily to realize the most effective and rational use of fishing grounds and fishery resources, the basic philosophy being that, through democratic organization by fishermen themselves, productivity would be stimulated and incomes and living standards eventually improved. Nowadays, Community Based Fisheries Management through democratic organization by fishermen themselves have to enforce at coastal fisheries. This Community Based Fisheries Management manage to fishery resources by fishermen themselves and harvest in collaboration with that resources. Therefore, this paper is intended to briefly to describe the entire system and the historical development of Japanese fishery legislation in order to assist in reform of our country fisheries management regime.

• The Journal of Fisheries Business Administration
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• v.54 no.1
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• pp.37-49
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• 2023

Climate change is a major global problem. Oysters, one of the most representative farmed fish in Korea, are attracting attention as candidates for blue carbon, an alternative to carbon neutrality. This study is analyzed by the SSP scenarios to determine the impact of oyster aquaculture production according to climate change. Based on the analysis, future productions of oysters are predicted by the SSP scenario. Significant differences by the SSP scenario are confirmed through predictive power tests among scenarios. Regression analysis was conducted from January 2001 to December 2014. As a result of the analysis, water temperature, water temperature quadratic term, salinity, salinity quadratic term, and month × water temperature cross term were estimated as significant variables. Oyster production which is predicted by the SSP scenario based on the significant variables from 2015 to 2022 was compared with actual production. The model with the highest predictive power was selected by RMSE and MAPE criteria. The predictive power was compared with the MDM test to determine which model was superior. As a result, based on RMSE and MAPE, the SSP1-2.6 scenario was selected as the best model and the SSP1-2.6, SSP2-4.5, and SSP3-7.0 scenarios all showed the same predictive power based on the MDM test. In conculusion, this study predicted oyster aquaculture production by 2030, not the distant future, due to the short duration of the analytical model. This study was found that oyster aquaculture production increased in all scenarios and there was no significant difference in predictive power by the SSP scenario.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.3
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• pp.183-191
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• 2007

The investigation for the species composition and catch in the deep East Sea was carried out with commercial trawlers from 2004 to 2006. The catches were 6,043kg and were composed of 43 species with 34 hauls between 250m and 1,030m in depth. The principal species caught were Allolepis hollandi, red crab (Chionoecetes japonicus), Careproctus rastrinus, Argis lar, Chionoecetes opilio, Malacocottus gibber, Petroschmidtia toyamensis, Pandalus eous Makarov, and Dasycottus setiger. The rate of discarded catches in situ was about 50%. The diversity indexes of 2005 and 2006 were 1.152 and 0.878, respectively, and the evenness indexes at those years were 0.752 and 0.583, respectively, which implied one dominant species caught in 2006.

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.28-31
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• 2001

Two specimens of the carangid fish Decapterus akaadsi Abe were collected for the first time in Busan, Korea. It is differentiated from the other three species of Decapterus by the number of rays in the dorsal and anal fins, gill rakers, scutes, and extent of predorsal scale. These specimens represent the first record of Decapterus akaadsi from Korea. A new Korean name 'Bulkeon karagi' is proposed for this species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.3
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• pp.278-286
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• 2017

The age and growth of marbled flounder Pseudopleuronectes yokohamae in coastal waters of the East Sea of Korea off Pohang were determined, by evaluating monthly samples of commercial catches, caught by gill nets and longlines from February 2013 to January 2014. New annuli from annually in P. yokohamae otoliths, and the boundary between the opaque and translucent zones forms from March to May. The relationships between total length (TL) and total weight (TW) were $TW=0.009TL^{3.128}$ ($R^2=0.969$) for females and $TW=0.008TL^{3.150}$ ($R^2=0.964$) for males. The TLs at the time of annulus formation, back-calculated from the otolith-length relationship by reference to the von Bertalanffy growth curves, were $L_t=52.63$ ($1-{\exp}^{(-0.231(t+0.033))}$) for females and $L_t=36.22$ ($1-{\exp}^{(-0.400(t+0.117))}$) for males. Commencing at the age of 3 years, females grew faster than males (P<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.916-922
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• 2023

An abnormal shape of Bathyraja brachyurops was first reported from the catch of a bottom trawl in the southwest Atlantic Ocean in June 2022. Both pectoral fins of the specimen did not fuse with the head, resulting in a horn-like structure separated from the sides of the eyes. Analysis of mitochondrial DNA cytochrome c oxidase subunit I sequences showed that our specimen was perfectly matched to Bathyraja brachyurops registered with the National Center for Biotechnology Information. Our specimen possessed the following morphological features: a pair of flexible but elongated and pointed horns on the head; rough dorsal disc, densely covered with numerous small denticles on the head, anterior margin of pectoral fins and median line of the disc; a thorn between the first and second dorsal fins; and a pair of large ocelli at the base of pectoral fins. Unlike the normal B. brachyurops, our specimen had a slender clasper and no nuchal thorns, which may be related to the morphological abnormality. The horn-like structure on the head may be owing to the lack of fusion between the pectoral fins and head during early embryonic development.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.1
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• pp.29-39
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• 2012

Currently, environment-friendly and sustainable fisheries are one of the major issues among fisheries authorities. A variety of alternative management policies and projects are going on to enhance fisheries management systems and fishery resources such as a TAC management program and a VDS (Vessel Day Scheme) management scheme for distant water fishing nations in Western and Central Pacific Fisheries Commission (WCPFC) convention area. These kinds of efforts among fisheries management authorities are aimed at limiting fishing capacity or fishing power. In terms of fisheries management, Fishing capacity and fishing power have increased the importance of the impact on a fishery and level of the resources. Increased fishing capacity and fishing power have caused not only depletion of fisheries resource, but also additional fishing cost. therefore, there is a clear need for authorities to manage fishing capacity and fishing power. It is also help ensure the conservation and sustainability of the fishery resources. Because of lack of data, absolute fishing power is difficulty to measure. The notion of relative fishing power is frequently used. In this study, relative fishing power was assessed using Mastuda (1991) method for fishing power index. The raw data for assessment was based on fishermen's logbook data from sampled fishing vessels in coastal snow crab gillnet fishery. Data Envelopment Analysis (DEA) method was used to assess fishing capacity. DEA is a linear programming methodology to measure the efficiency of a set of entities called Decision-Making Units (DMUs). It was recommended by FAO for assessing capacity in fisheries.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.467-479
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• 2021

The distribution and abundance of fish eggs and larvae were investigated from February to December 2020 along the coastal waters of Korea. The eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and 16s rRNA gene. During the study period, eggs of overall 45 taxa belonging to 26 families were collected and larvae of overall 39 taxa belonging to 23 families were collected. In Yeongil Bay, eggs of Engraulis japonicus, which accounted for 83.9% of the total population, was the most dominant species, followed by Sardinops sagax (4.0%), Repomucenus valenciennei (3.8%) and E. japonicus larvae, which accounted for 34.9% of the total population. These were followed by Sebastiscus marmoratus (31.0%). In Gomso Bay, E. japonicus eggs accounted for 61.7% of the total population, followed by Sillago japonica (14.0%), Johnius grypotus (8.8%) and Pholis fangi larvae, which accounted for 53.5% of the total population, followed by Ammodytes personatus (34.1%). In Jinhae Bay, E. japonicus eggs accounted for 86.0% of the total population, followed by Leiognathus nuchalis (4.1%), Konosirus punctatus (3.7%) and E. japonicus larvae, which accounted for 48.7% of the total population, followed by Parablennius yatabei (21.6%).

• Korean Journal of Ichthyology
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• v.20 no.4
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• pp.291-302
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• 2008

Seasonal variation of species composition in the coastal waters off Wangdol-cho were investigated using the catches by gill net and trammel net from 2002 to 2004. A total of 58 species was collected and classified into 15 orders and 34 families. Of the 58 species identified, Scorpaeniformes and Perciformes accounted for 62.1% of the species. 35 species in 11 orders and 22 families were collected by gill net and 51 species in 15 orders and 30 families were collected by trammel net. The number of species was high in summer and autumn and lowest in winter. Catches were correlated with sea water temperature. The numbers of individuals and their biomass were 5,295 inds. and 1,890 kg, with the highest values achieved in summer and the lowest in spring. The most dominant species were Pleurogrammus azonus and Gadus macrocephalus. The seasonal species community showed a high similarity between summer and autumn.