• Fisheries and Aquatic Sciences
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• v.24 no.4
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• pp.153-162
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• 2021

In this study, a fish metabolic accelerator (a combination of butaphosphan and cyanocobalamin [BPC]) was injected into the muscle of the olive flounder, Paralichthys olivaceus, to investigate its effect on immunity and stress in fish maintained at low temperatures. A single dose of BPC was injected (100 mg/kg body weight) into the olive flounder, and its immunity and stress were observed after one and two weeks. Immunity tests revealed the presence of lysozyme (LZM), nitroblue tetrazolium (NBT), myeloperoxidase (MPO), anti-protease (AP), glutathione peroxidase (GPx), and total immunoglobulin (TIg). BPC injection was found to increase immunity activity compared to the control group. In particular, there was significantly high GPx activity. There was similarly high activity for MPO and GPx in the first week following the injection, followed by significant differences between the BPC-injected and control groups in the second week. There was a reduced low water-temperature stress response in the BPC-injected fish, as evidenced by the cortisol and glucose levels of the control and BPC groups. Lower levels were also observed in the BPC group than the control group during the second week. Cortisol levels were significantly lower in the BPC group than the control group. Histological examinations were conducted in the first and second weeks after the intramuscular injection of the recommended BPC dose to confirm the safety of BPC in aquaculture. There were no abnormalities observed in any tissue samples. This study confirms that the injection of BPC is safe even when used in a culture situation. BPC helps relieve stress and improves non-specific immune responses (innate immunity) in the olive flounder.

• Journal of fish pathology
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• v.34 no.1
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• pp.1-7
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• 2021

Red sea bream iridovirus (RSIV), belonging to the genus Megalocytivirus, is the predominant cause of mortality in marine fishes in Korea, including rock bream (Oplegnathus fasciatus). Rockfish (Sebastes schlegelii) are the host fish for RSIV, exhibiting no clinical signs or mortality. Cohabitation challenges, which mimicked natural transmission conditions, were performed to evaluate viral transmission between rock bream and rockfish, and to determine the pathogenicity and viral loads. In cohabitation challenge, artificially RSIV-infected rock bream were the viral donor, and healthy rockfish were the recipient. The results showed that although the donor rock bream had 95-100 % cumulative mortality (>10⁸ viral genome copies/mg of spleen 7-14 days after viral infection), the recipient rockfish did not die, even when the viral genome copies in the spleen were >10⁵ copies/mg. These results indicated asymptomatic infections. Notably, in a reverse-cohabitation challenge (artificially RSIV-infected rockfish as the viral donor and healthy rock bream as the recipient), RSIV horizontally infected from subclinical rockfish to rock bream (10⁷ viral genome copies/mg of spleen 21 days after cohabitation) with 10-20% cumulative mortality. These results suggest that an asymptomatic, infected rockfish can naturally transmit the RSIV without being sacrificed.

• Journal of fish pathology
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• v.37 no.1
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• pp.147-153
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• 2024

The World Organization for Animal Health (WOAH) recommends two protocols (ITS and COI) for conventional PCR of G. salaris diagnosis. However, ITS PCR protocol may yield false-positive results, leading to unnecessary countermeasures. It's difficult to distinguish between G. salaris and false-positive by similar amplicon size of PCR, since the amplicon size of ITS PCR in G. salaris and false-positive was 1,300 and 1,187 bp, respectively. The nucleotide sequences of ITS false-positive in rainbow trout is 99.7% identical to previously reported host genome sequences of rainbow trout (Oncorhynchus mykiss) and 95.3 to 89.1% identical to those of other salmonid fish species. To reduce false-positive PCR band, PCR was performed by the different annealing temperature, but PCR bands were still detected. In RFLP analysis by HaeIII, the PCR product of G. salaris was digested into four bands of 512, 399, 234 and 154 bp, while the false-positive was digested into seven bands of 297, 263, 242, 144, 93, 80 and 68 bp. In the RFLP patterns digested by HindIII, G. salaris showed two bands of 659 and 640 bp, while false-positive had one fragment of 1,187 bp without any digestion. Therefore, the RFLP method of ITS PCR with HaeIII and HindIII can be used for differentiation between G. salaris and false-positive. These results might provide important information on the improvement of PCR diagnostic method of G. salaris.

• The Journal of Fisheries Business Administration
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• v.34 no.2
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• pp.1-25
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• 2003

During the past 100 years, Korean fisheries management policies have enforced the license system, it is the most typical regulation system in Korean fisheries. Even now, it has caused resource management failure, it has also invited economic inefficiency and inequity. Accordingly, the Korean government has recently introduced the self-regulatory management system for fishermen with the TAC system. These systems are one of the most market-oriented regulation systems in fisheries management systems. It is defined as regulatory policy tools other than regulations with command and control approach. It is also called “alternatives” which is composed of regulatory alternatives and non-regulatory alternatives. The self-regulatory management system and the ITQ system are cooperative-based co-management between government and fishermen as an alternative management strategy ; it is gaining the increasing attention to improve the effectiveness of fisheries management in Korea. It is expected not only to positively improve function in fisheries regulation, but also to decrease inefficiency in fisheries policies. However, these systems have many problems. The monopolization of rent is one of the typical examples. As solutions for the problem in the aspect of fishery management, fisheries policy is need of approach to industrial organization. For instance, Contestable market theory is one of the good theoretical background, it mean that market is able to free entry and free exit. Thus, fisheries management carry out policies such as revitalization of the used market of capital goods in fisheries, organize of the self-regulatory management group. Conclusively, as the exploiters and managers, fishers and the government should put emphasis on improving economic efficiency so that fishery would grow as an industry that contributes to the increase of social welfare, and the change to that direction will be the only way for our fisheries to preserve its importance.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.340-347
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• 2019

We performed a safety survey on residual pesticides in dried agricultural products. A total of 110 samples of dried agricultural products distributed in Gyeonggi-do were analyzed for 263 pesticides according to multi class pesiticide multiresidue method. Ten types of pesticides were detected in 10 samples. Chlorpyrifos was detected in Ricinus communis leaves, chlorpyrifos, hexaconazole, pyridalyl in Chwinamul (wild aster), diniconazole, isoprothiolane, lufenuron in radish leaves, hexaconazole in Cirsium setidens (Korean thistle), bifenthrin, and chlorothalonil, boscalid, and pyraclostrobin in pepper leaves. The detection rate of pesticides was 9.1%, and among these samples, one was detected over Maximum Residue Limits (MRLs). In the validation study, the values of limit of detection (LOD), limit of quantitation (LOQ), coefficient of determination ($R^2$) and recovery were in the range of 0.002~0.027 mg/kg, 0.006~0.083 mg/kg, 0.9964~1.0000 and 74.8~118.9%, respectively. The Positive List System (PLS) was newly introduced as part of the safety management of residual pesticide in agricultural products in Korea in 2019. With the application of the PLS, if the MRL is not established, 0.01 mg/kg limit is applied uniformly. In spite, these of strengthened residue limits, the MRLs of dried agricultural products are still insufficient. Therefore, this study could be utilized as basic data for the setting of proper MRLs.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.259-265
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• 2021

A diagnostic test for viral hemorrhagic septicemia virus (VHSV), which infects more than 80 species of freshwater and marine fish at home and abroad, causing mass mortality, was conducted to provide quantitative data on the amount of virus expression in various tissues of flounder in chronological order. The tissues were collected in chronological order after the intraperitoneal injection of 3.0E+07 tissue culture infective dose₅₀ (TCID₅₀) per 0.1mL per fish of VHSV to randomly selected flounder. As a result of relative quantification through real-time PCR, the highest levels of virus expression were found in the spleen, kidney, gill, and liver on day 5. This study proved that the spleen was an appropriate site for the final diagnosis of VHSV in the early stages of infection and will provide important information for the diagnosis of legal infectious diseases in Korea.

• Fisheries and Aquatic Sciences
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• v.25 no.2
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• pp.101-116
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• 2022

The harvesting season of lompa fish, Thryssa baelama, through sasi, indigenous knowledge in resources management, in Haruku Village has become a socio-cultural event that attracts many people. The sasi of lompa fish has been conducted for hundreds of years. Information on the bioecology aspect of lompa fish is limited, while this information is crucial for lompa fish sustainability through the sasi approach. This study aimed to investigate some population parameters of lompa fish, its sustainability status, and proposed a sustainable management strategy for the lompa fishery of Haruku Village. Fish population parameter covers length-weight relationship, growth pattern, size distribution, sex ratio, and the body condition index. The sustainability status was assessed following the Rapfish approach. Fisheries management strategy was performed using a conceptual model framework based on Driver Pressure State Impact Response. The research shows that the total length varies between 9.2-14.3 cm. A high relationship was found between total length and weight, and the growth pattern was an allometric negative. There was a difference in sex ratio between males and females, with females dominant. The body condition index varies over time, probably due to reproductive status. The overall sustainability status was at fair condition (61.60%), with the ecological domain having the highest sustainable status (71.07%) and considered sustain. In comparison, the technological domain had the lowest sustainability status (52.58%) and was considered fair sustain. There were seven management strategies proposed for sustainable management for the lompa fishery.

• Fisheries and Aquatic Sciences
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• v.27 no.4
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• pp.213-224
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• 2024

Betta rubra, classified as endangered fish species by the International Union for Conservation of Nature (IUCN), has been successfully bred and raised in captivity for two generations under laboratory conditions. This study aimed to provide comprehensive information on the captive breeding of B. rubra, focusing on various parameters crucial for ex-situ conservation and domestication. The research involved breeding trials, embryo and larvae observation, first feeding experiments, larva and fry rearing trials, and the evaluation of growth and reproduction in two generations. The study revealed that the female B. rubra, with an average total length of 5.17 ± 0.15 cm and weight of 1.61 ± 0.06 g, produced an average of 73.67 ± 7.09 eggs, 34.33 ± 5.13 total larvae, and exhibited a hatching rate of 46.67 ± 5.77%. The embryogenesis process commenced on the day of spawning (dps) and continued until the eggs hatched at 6 dps. Larvae development and yolk absorption occurred from 0 to 6 days post-hatching (dph). The study also examined the impact of different initial feeding options, with chopped Tubifex resulting in the most significant in- crease (p < 0.05) in length. The growth pattern of B. rubra larvae showed slow initial growth during the first seven days, followed by a rapid exponential growth phase from day 8 to day 39. Two generations of B. rubra (G1 and G2) were successfully bred in captivity, with G2 showing a better tendency for growth in length and weight compared to G1. Notably, there were no significant differences (p > 0.05) in reproductive success between the wild-origin broodstock (G0), G1, or G2. This research contributes valuable insights into the captive breeding of B. rubra and its early life stages, offering critical information for the conservation and sustainable management of this endangered species. Further research is needed to explore the long-term effects of domestication on behavior, physiology, and phenotypic diversity.

• The Journal of Fisheries Business Administration
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• v.37 no.1 s.70
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• pp.1-24
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• 2006

Reducing fishing capacity is one of current issues in the international fisheries. This is because that increased fishing capacity has caused not only fish stocks to be depleted, but also additional fishing costs to be incurred, which resulted in reduction of economically viability of fisheries. For this reason, FAO adopted the International Plan of Action for the Management of Fishing Capacity' in 1999 and recommended member countries to estimate fishing capacity and to implement the policy to reduce fishing capacity. This study is aimed to measure fishing capacity of the Large Purse Seines Fishery that is one of offshore fisheries in Korea using both Peak - to - Peak Analysis and Data Envelopment Analysis in order to provide a policy information for preparation of domestic plan of action for the management of fishing capacity. The results of PTP Analysis were almost similar to those of DEA Analysis. The DEA results showed that the capacity utilization in 2004 was about 75%, it was obvious the capacity did not utilize enough. The sensitivity analysis on DEA results indicated that 24% of the number of ships, 26% of the tonnages, or 29% of the horse powers should be reduced if the present catch remained. In addition, if the catch remains at the MSY base level of large purse seines, the analysis suggested that the number of ships, tonnages and horse powers should be reduced by 15%, 18%, and 21% respectively.

• Journal of Fisheries and Marine Sciences Education
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• v.22 no.3
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• pp.388-401
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• 2010

This research aims at analyzing impacts of climate change on fisheries. Climate change is an additional pressure on top of the many which fish stocks already experience. This implies that the impact of climate change must be evaluated in the context of other anthropogenic pressures, which often have a much greater and more immediate effect. Conversely, it is evident that fish stocks will be more resilient to climate impacts if the stresses due to other factors, such as over-fishing and pollution, are minimized. Improved management of fisheries and of marine ecosystems can undoubtedly play an important role in adapting to the impacts of climate change. Most of the improvements which are needed do not require new science or understanding, they require patient development of acceptable, effective, responsive social institutions and instruments for achieving adaptive management. Management advices must include complete and transparent information on risks and uncertainties which arise from data quality and from structural deficiencies in the assessment models. Well-designed and reliable monitoring of fish stocks and the marine ecosystem is essential in order to detect changes and give warning in advance of alterations in the productivity of individual species and of the structure and functioning of the ecosystem and fishery economy on which they depend.