• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.2
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• pp.147-161
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• 2011

Korea is surrounded by sea on three sides. This country has been supplied with a variety of aquaculture products cultivated on shores. There have recently been a lot of studies to have better understanding of the correct location and quantity of aquaculture farms for seaweed, ear shells and fish that cover a wide area of sea. And it is necessary to use the geographic information system and remote sensing to detect the aquaculture farms in order to effectively manage them. This study uses higher resolution aerial images(25 centimeters) than satellite images of 2~2.5-meter resolution that have been ever used, to conduct an accuracy detection of aquaculture farming facilities. It chooses as the case study area the Wando region that has aquaculture farms for seaweed, ear shells and fish. Aerial photos of the island were obtained in this study and an image correction of them was conducted. A spatial database was then constructed in this study and the detection of aquaculture farming facilities was performed. An analysis of facilities inside and outside the permitted areas reveals that there has been an increase in the facilities of seaweed and ear shell aquaculture farms outside the permitted areas. And also it tells that because the facilities of fish aquaculture farms have turned into those of ear shell aquaculture farms, there has been a decrease in permitted facilities, facilities detected on the basis of aerial images, and facilities outside the permitted area. It will be necessary to continuously control and manage the unpermitted facilities, regarding the increase in the facilities inside and outside the permitted area for seaweed and ear shell aquaculture farms. Because the facilities of aquaculture farms cover a wide range of areas(sea) in this manner, it is more effective to depend on high resolution aerial images than a field survey to detect and calculate the facilities. This study comes up with a plan for using aerial images to detect the location and the quantity of the fish aquaculture facilities and then effectively manage them.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.115-118
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• 2000

The production of cultured coho salmon (Oncorhpchus kisutoh) in Korea has being increased year after year. Smolt being reared in freshwater suffer transferring into seawater and are farmed in cages for fattening. This handling processes including transportation, confinement into cages are unavoidable stress to fish in salmon farming and often end up to mass mortality, This study aimed to investigate the impact of handling process on the stress responses of coho salmon. The indicator of stress was measured by cortisol to be a first response, and for the second response test, glucose, triBlyceride, cholesterol, lactate and electrolyte of $K^+, Na^+, Cl^-$ in serum and the activities of alanine aminotrtnferase (ALT), aspartate aminotransferase(AST) and lactate dehydrogenase (LDH) were analyzed. As a result, the concentration of cortisol, glucose as well as LDH activity were significantly increased, whereas others showed no difference comparing with control group. It obviously demonstrated that handling process made fish stressful.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.1
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• pp.38-44
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• 2016

The quality and quantity of live food sources strongly influence the success of fish production in farming operations. Thus, critical studies of live forage species are a crucial element for progress in fish aquaculture. The fat content of food is an especially important determinant of growth in marine fish. Omega-3 highly unsaturated fatty acids (HUFA) are essential components of diet that determine the nutritional value of larval fish. Euglena is a protist that has potential as a forage species. These single-celled organisms have plant and animal characteristics they are motile, elliptical in shape and 15–500 μm in diameter. Their nutritional content is excellent, but most studies have focused on cells raised in autotrophic culture. We therefore examined differences in the lipid and fatty acid contents, and the growth of Euglena cells grown under autotrophic, heterotrophic, and mixotrophic conditions. Biomass production reached 15.03 g/L, 12.28 g/L, and 3.66 g/L under mixotrophy, heterotrophy, and autotrophy, respectively. The proportional n-3 HUFA content differed among culture methods: 10.04%, 5.80% and 10.01% in mixotrophic, heterotrophic and autotrophic cultures, respectively. Mixotrophy was to be the best form of cultivation for improving the growth and nutritional content of Euglena.

• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.290-294
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• 2012

Vibrio spp. and Streptococcus spp. have caused a considerable disease of farmed fish and economic loss in fish farming and seafood industry. In this study, the efficacy of an aquatic disinfectant tablet composed to calcium hypochlorite was evaluated against V. anguillarum and S. iniae. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to test bacteria for 30 min at $4^{\circ}C$. An aquatic disinfectant tablet and test bacteria were diluted with distilled water (DW), hard water (HW) or organic matter suspension (OM) according to treatment condition. V. anguillarum on the DW, HW and OM condition was completely inactivated with 16,000 15,000 and 13,000 fold dilutions of the disinfectant, respectively. On the DW, HW and OM condition, S. iniae was absolutely inactivated with 17,000 16,000 and 14,000 fold dilutions of the disinfectant, respectively. As an aquatic disinfectant tablet possesses bactericidal efficacy against fish pathogenic bacteria such as V. anguillarum and S. iniae this disinfectant solution can be used to control the spread of fish infective bacterial diseases.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1444-1458
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• 2016

The expansion of high-density aquaculture in the limited waters has caused a wide variety of problems. The problems include environmental problems nearby aquaculture sites, growth rate of aquatic organisms, quality decline of farmed fish and price fall in the market. The phenomenon of aquaculture industry happens in not only inshore but also offshore. Therefore, the fisheries authorities have been changing their policy paradigms from mass production to sustainable production based on ecosystem. Other countries, however, focusing on relieving poverty and providing protein from fish production have not recognized the degree of seriousness. When it comes to enhancing the problems, National Institute of Fisheries Science has been developing the technology of Integrated Multi-Trophic Aquaculture (IMTA) to reduce and to prevent contaminants from fish and aquaculture sites, remained feed from fish farming process. In long-terms of view, the system is one of the most sustainable fishery production methods based on ecosystem. As integration of nutrient feed system from aquatic organisms is firmly established, the earlier mentioned problems will be diminished gradually. In term of the substantiality, this study was conducted. The research on management system for IMTA also has been incorporated. This study also investigated the features and current status of IMTA and demonstrated the developed management system and direction for the future advancement.

• Journal of Environmental Science International
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• v.23 no.10
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• pp.1703-1718
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• 2014

An eco-friendly integrated multi-trophic aquaculture (IMTA) farming technique was developed with the goal of resolving eutrophication by excess feed and feces as fish-farming by-products. A variety of seaweed species were tried to remove inorganic nutrients produced by fish farming. However, there have been few trials to use Sargassum fulvellum in an IMTA system, a species with a relatively wide distribution across regions with various habitat conditions, great nutrient removal efficiency and importance for human food source and industrial purposes. In this regard, our study tried to examine feasibility of using S. fulvellum in an IMTA system by analyzing growth characteristics of the species in an IMTA system comprising of rockfish (Sebastes shlegeli), sea cucumber (Stichopus japonocus) and the tried S. fulvellum (October 2011 - November 2012). We also monitored environment conditions around the system including current speed, water temperature and inorganic nutrient level as they may affect growth of S. fulvellum. S. fulvellum in the IMTA system, which were $15.72{\pm}5.67mm$ long at the start of the experiment in October 2011, grew to a maximum of $1093{\pm}271.13mm$ by May 2012. In September, seaweed growth was reduced to a minimum of $280{\pm}70.43mm$ in length. Then, S. fulvellum began to grow again reaching $325{\pm}196.19mm$ by November 2012. Wet weight of the seaweed was $4.01{\pm}1.89g$ at the start of the experiment and reached a maximum of $109.26{\pm}34.23g$ in May. The weight gradually declined to a low of $15.12{\pm}8.40g$ in September 2012. Weight began to increase once more, rising to $39.27{\pm}21.69g$ by November. During the experiment, the average velocity at the surface and the bottom was 6.5 cm/s and 3.4 cm/s, respectively. The water temperature ranged $5.0-23.5^{\circ}C$, which was considered suitable for growing S. fulvellum. Results of the study indicated no significant differences in inorganic nutrients between pre- and post-IMTA installation. It was thus concluded that S. fulvellum can be a suitable seaweed species to be used in an IMTA system.

• Journal of Life Science
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• v.24 no.7
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• pp.757-761
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• 2014

Olive flounder (Paralichthys olivaceus) is an important aquaculture fish species in Jeju Island, South Korea. Due to the intensification of flounder fish farming, huge amounts of chemical antibiotics are used against several fish diseases. This has many harmful side effects on fish, as well as human consumers. Hence, an alternative to chemical antibiotic agents is needed for disease control. In this study, three strains of rhizobacteria (BRH433-2, TRH415-2, and THJ609-3) were isolated from the rhizosphere of plants. Assays of their antibacterial activity against fish pathogens, such as S. iniae, S. parauberis, V. anguillarum, and E. tarda, were performed with untreated broth culture (without cell separation), supernatant, and precipitated pellets separated by centrifugation. Among these, the cell suspension prepared from the precipitated pellet showed significant antimicrobial activity when compared with that of the untreated broth culture and centrifugal supernatant. These results indicate that the three isolated rhizobacterial strains exhibit antibacterial activity. Analysis of the 16S rDNA sequences of the BRH-433-2, THJ609-3, and TRH415-2 strains showed the highest similarity to Burkholderia gladioli (99.5%), Pseudomonas baetica (97.7%), and P. koreensis and P. baetica (98.4%), respectively. We suggest that the strains hold promise in disease management of fish.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.406-412
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• 2014

To evaluate the influence of burrowing substrate on the rearing performance and ambicoloration of cultured flounder, Paralichthys olivaceus, we compared the daily food intake (DFI), feed efficiency (FE), survival, growth, proportion of pigmented skin on the blind side, and proportion of ambicolored fish. We reared juvenile flounders [total length (TL) $4.46{\pm}0.06cm$, body weight (BW) $0.77{\pm}0.03g$] in dark-green fiberglass-reinforced plastic (FRP) aquariums without (control) or with gravel substrate at a density of 200 fishes/ton for 120 days. While there was no difference in survival rate or growth, the DFI was lower and FE higher in the group raised with substrate than in the control. The proportions of pigmented area on the blind side and ambicolored fish were significantly higher in the control tank. Therefore, the supplement of substrate on the aquarium bottom positively affects the feeding efficiency, and inhibits abnormal pigmentation on the blind side in flounder farming at high density.

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1443-1457
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• 2020

The emergence and spread of antimicrobial resistance in pathogenic bacteria of fish and shellfish have caused serious concerns in the aquaculture industry, owing to the potential health risks to humans and animals. Among these bacteria, Aeromonas salmonicida, which is one of the most important primary pathogens in salmonids, is responsible for significant economic losses in the global aquaculture industry, especially in salmonid farming because of its severe infectivity and acquisition of antimicrobial resistance. Therefore, interest in the use of alternative approaches to prevent and control A. salmonicida infections has increased in recent years, and several applications of bacteriophages (phages) have provided promising results. For several decades, A. salmonicida and phages infecting this fish pathogen have been thoroughly investigated in various research areas including aquaculture. The general overview of phage usage to control bacterial diseases in aquaculture, including the general advantages of this strategy, has been clearly described in previous reviews. Therefore, this review specifically focuses on providing insights into the phages infecting A. salmonicida, from basic research to biotechnological application in aquaculture, as well as recent advances in the study of A. salmonicida.

• Journal of Aquaculture
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• v.12 no.4
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• pp.323-331
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• 1999

Most of channel fish farming in Alabama are still earthen pond style, and filled by rainfall and runoff. The water levels of ponds are maintained with stand-pipe, and the effluent from ponds very little discharged at usual time except ant heavy rains and crop season. Overflow from ponds following rains occurs mostly in winter and early spring when stream flows high. In this study to know how much effluents fish ponds affected to streams which are nearby ponds, a survey carried out on the variation of water quality of seven streams and effluents at heavy rains. Water samples were collected at 14 sites on upstream (did not affected by effluents) and downstream(being affect by effluents), and sampled monthly from August 1997 to August 1998. There were no clear trends of difference in most water quality variables between upstream and downstream of catfish farms during a year. The effluents from ponds after heavy rains were not highly polluted, but sometimes have elevated concentrations of TSS. Nitrogen content of effluents was higher than that of routine streams , but phosphorus was not clear. From this result suggest than the effluents from catfish farm are not having adverse impacts on stream water quality still yet .