• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.914-919
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• 1998

This study was conducted to evaluate the purification efficacy by filter and ultra violet (UV) irradiation against inlet and outlet seawater of the land based fish farm. Purification efficacies for inlet seawater (50$\ell$/min) has been examined with filter of 60$\mu$m pore size and UV irradiation at an average dose 0.5 mWS/$cm^2$ for 5 months. For outlet seawater filter of 90 $\mu$m pore size only was used. Temperature, salinity, pH, $NO_3-N,\;NO_2-N,\;NH_4-N,\;PO_4-P$, DO and COD of inlet and outlet seawater in the system were not influenced. However, the removing rate of suspended solid and turbidity of inlet seawater were appeared to be $48.7\~65.6\%$ (average $51.9\%$) and $33/3\~42/5\%$ (average $34.8\%$) after passing through screen filter respectively. Also, germicidal efficiency to the total bacteris and Vibrio species were $16.7\~20.2\%$ (average $19.2\%$) $20.0\~21.9\%$ (average $20.9\%$) respectively after passing through UV irradiation. After passing through drum filter of 90$\mu$m pore size, suspended solid and turbidity of outlet seawater were appeared to be $42.7\~52.6\%$ (average $46.9\%$), $27.7\~29.9\%$ (average $28.3\%$), respectively.

• Journal of Environmental Health Sciences
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• v.39 no.4
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• pp.376-382
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• 2013

Objectives: The objectives of this study were to identify the virucidal efficacy against the viral hemorrhagic septicemia virus (VHSV) of an aquatic disinfectant tablet composed of calcium hypochlorite. Methods: Virucidal efficacy was determined through the viability of VHSV contacted with the disinfectant in a viral stock cultured in a fathead minnow cell line. An aquatic disinfectant tablet and VHSV were reacted under distilled water (DW), hard water (HW) or organic matter suspension (OM) conditions. Results: Under DW and HW conditions, VHSV was inactivated with 24,000- and 2000-fold dilutions of the aquatic disinfectant tablet, respectively. With the investigation of the antiviral effect of the disinfectant under OM conditions, VHSV was inactivated with a 16,000-fold dilution of the aquatic disinfectant tablet. Conclusions: The results from this study showed that the aquatic disinfectant tablet was a highly effective disinfectant against VHSV. In the future, a controlled field trial is required to determine whether the use of an aquatic disinfectant tablet will be able to reduce VHSV in a cultured marine fish farm.

• Journal of fish pathology
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• v.17 no.3
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• pp.207-211
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• 2004

The present study was conducted to research some Actinosporeans species in Oligochaetes (Branchiura sowerbyi). From April to May, 2004, Oligochaetes were sampled from the Daewi Reservoir located in Kunsan, Jeonbuk and a drainageway of the fish farm located in Wanju, Jeonbuk. Tow species of Actinosporeans not reported yet in Korea, Raabeia sp. and Triactinomyxon sp., were detected from Oligochaetes. Actinosporeans detected are recorded to Raabeia sp. E and Triactinomyxon sp. F. A total of 200 Oligochaetes were investigated from two sites, and 28 individuals (14%) were found infected: 27 individuals (13.5%) with Raabeia sp. E and one individual (0.5%) with Triactinomyxon sp. F.

• Journal of Marine Bioscience and Biotechnology
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• v.6 no.1
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• pp.17-25
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• 2014

Periodically, harmful algal blooms (HABs) have occurred, with impacts on various areas including public health, tourism, and aquatic ecosystems, especially aquacultured and caged fisheries. To prevent or manage invasions of HABs into fish farms on an emergency basis, many methods have been proposed. Frequently over the past 30 years in coastal countries, treatments of clay and clay mixed with polyaluminum chloride (PAC) and chitosan have been tested for HAB-removal effectiveness in both the laboratory and the field. In Korea, yellow loess clay (hwangto) has been dispersed using electrolytic clay dispensers, both to decrease the amount of yellow loess clay's usage in containers and enhance HAB-removal efficiency. However, this emergency method has limitations, among which is the requirement for more effective controlling agents for field applications. Thus, in this paper, we review technologies for clay-based red tides prevention and control and their limitations, and, further, introduce next-generation algicidal technologies for the emergency protection of fish farms.

• Journal of fish pathology
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• v.25 no.2
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• pp.85-93
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• 2012

Many metacercariae in the musculature of southern top mouthed minnow (Pseudorasbora parva) cultured at a farm in Chonbuk Province. The excysted metacercariae looked yellowish white and were $4.02{\pm}1.80$ mm (1.66-5.81) in length and $1.27{\pm}0.27$ mm (1.01-1.64) in width for acetocarmin-stained specimens. The oral sucker measuring $0.18{\pm}0.05$ mm (0.11-0.24) in length and $0.23{\pm}0.07$ mm (0.15-0.33) in width, was located at the anterior end of the body. The ventral sucker situated at the fourth third of the body were measured $0.47{\pm}0.08$ mm (0.35-0.53) in length and $0.55{\pm}0.09$ mm (0.43-0.63) in width. The tongue-shaped metacercariae were identified as Clinostomum complanatum on the basis of morphological characteristics. The metacercaria was also confirmed to be C. complanatum using PCR reaction with C. complanatum-specific primer sets, Trem 18S F and Ccom670 R. No histopathological changes in the infected fish were observed except necrosis and exfoliation of epidermis in the skin and atrophy of muscle fibers.

• Advances in environmental research
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• v.5 no.3
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• pp.179-187
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• 2016

This study evaluated some markers of oxidative stress in the organs of African Catfish, Clarias gariepinus from Eleyele River in Oyo State, Nigeria. Clarias gariepinus (250 g-400 g) were collected from Eleyele River (a suspected polluted River) and Clarias gariepinus from a clean fish farm (Durantee fisheries) were used as the control. Levels of Malondialdehyde (index of lipid peroxidation), Glutathione (GSH) and activities of antioxidant enzymes- Superoxide dismutase (SOD), Catalase and Glutathione-S-Transferase (GST) were evaluated in the liver, kidney and gills of the fish. From the results, there were significant (p<0.001) increases in malondialdehyde and GSH levels in the liver, kidney and gills of Clarias gariepinus from Eleyele River compared with control. The activity of GST increased significantly (p<0.05; p<0.001) in the liver and kidney of fish from Eleyele River compared with control. There was a significant decrease (p<0.05; p<0.001) in SOD activity in all the organs of Clarias gariepinus from Eleyele River compared with conrol and also a significant (p<0.001) decrease in catalase activity in the gills and kidney of the fish but catalase activity increased in the liver. Increase in lipid peroxidation and alterations in antioxidant status in Clarias gariepinus from Eleyele River show that the fish were under oxidative stress. These suggest that the River is polluted probably as a result of various wastes frequently discharged into the River. This could pose serious health risks to consumers of water and aquatic organisms from the River.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.5
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• pp.179-186
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• 2021

We need measures that can come up with alternative about fishery living zone and enhance local acceptance for responding to the increase in the proportion of renewable energy production and construction of 12GW Offshore wind power according to Korea's Renewable Energy 3020 initiative and Korean-version New Deal. In this study, We suggest that differentiation plans of co-location model in connection with offshore wind power generation suitable for the East Sea. The East Sea is an optimal site for building of a floating offshore wind power generation(FOWPG) field. It is expected that economic effects like energy production, aquatic resource development and tourism industrialization by farming bluefin tuna which is high valued fish and suitable for offshore aquaculture on public waters in FOWPG field. And we can confirm that budget reduction, smart management by sharing operation management technology and increase in fishermen income.

• Journal of Life Science
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• v.28 no.9
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• pp.1118-1126
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• 2018

In this study, investigated the general characteristics and diagnostic methods types of streptococcosis among various fish disease pathogens that caused a lot of economic damaged to aquaculture fish based on the previous research paper. Streptococcosis infection of fish is considered a reemerging disease affecting a variety of wild and cultured fish throughout the world. Calssifiacation of Gram positive cocci based on DNA-DNA hybridization coupled with 16S sequencing has shown that at least five different species are considered of significance as fish pathogens: Lactococcus garvieae, L. piscium, Streptococcus iniae, S. agalactiae, S. paruberis, Vagococcus salmoninarum. Symptoms of infection with streptococcosis disease such as body color change, eyeball abnormality, gill discoloration, bleeding, abdominal distension, swelling of the kidney and spleen. In addition, it usually occurs from June to October when the water temperature rise a lot of fish death. Currently, 16S rRNA, 16S-23S rRNA intergenic spacer region (ISR), Random Amplified polymorphic DNA (RAPD), Ribotyion (RT), Loop-mediated isothermal amplification (LAMP) are among the methods for diagnosing streptococcosis. Among them, the LAMP method, which is high applicable to the aquaculture farm has attracted the spotlight, but due to problems such as confirmation of results. This seems to minimize the economic loss of streptococcosis which complements the problem so that it can be easily used from the diagnosis to the results confirmation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.3
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• pp.176-180
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• 1992

Nitrification Is an important facet of water recycling fish culture system, because the toxic cation ammonia is converted to the innocuous anion nitrate. This study was attempted to find the optimal design factor of submerged filter for ammonia removal in water recycling fish culture system. The experimental system was designed submerged filter with corrugated skylight plate, and operated in the fish farm, National Fisheries University of Pusan. When the influent ammonia concentration was about 10mg/l (9.43-13.66mg/l) nitrification rates were tested for the removal of ammonia over a four stage of the hydraulic loadings. The submerged filter removed 76.24, 62.88, 39.09 and $9.20\%$ of the ammonia to hydraulic load of 0.028, 0.037, 0.056 and $0.111m^3/m^2$. day, respectively. We can apply the above data to the material balance on the ammonia concentration in a fish reservoir, and conclude that the maximum allowable ammonia production was 1.52mg/min, and the optimal hydraulic loading was $0.047m^3/m^2$\;\cdot day$, in order to maintain the ammonia concentration below 10mg/l in the fish reservoir.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.501-506
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• 1999

This study was conducted to evaluate the purification efficiency in rearing water of the land based fish farm by screen filter and ultra violet (UV) irradiation. Purification efficiency for rearing seawater has been examined with screen filter of 60 $\mu$m pore size and UV irradiation at dose of 0.5 $mWS/cm^2$ for 5 months. Purification efficiency by changing of temperature, salinity, pH, DO, total bacteria and Vibrio species in rearing seawater by filtering and UV irradiation were not significant during 5 months, However, the removing rate of suspended solid and turbidity of rearing seawater were $43.8\~45.6\%$ (average, $44,7\%$) and $29.2\~33.2\%$ (average, $31,3\%$) by filtering, respectively. Also, Purification efficiency for the $NO_3^{-}-N,\;NO_2^{-}-N,\;NH_4^{+}-N$ and $PO_4^{3-}-P$ were $21.3\~21.9\%$ (average, $21.6\%$), $24.1\~25.2\%$ (average, $24.7\%$), $17.6\~17.8\%$ (average, $17.7\%$) and $19.0\~20.4\%$ (average, $19.7\%$) respectively by the system used on this study.