• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.326-327
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• 2006

• Proceedings of the Korean Aquaculture Society Conference
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• 2005.05a
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• pp.59-60
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• 2005

• Journal of Aquaculture
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• v.14 no.2
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• pp.67-71
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• 2001

Phosphorus is an essential element for growth and metabolism in fish. However high levels of phosphorus in the feed can lead to poor water quality of pond, and can also be a potential source of pollution, when pond water is released to the environment. In this study phosphorus supplemented diets containing 0.0, 0.9 or 1.9% of (dicalcium) phosphate were offered to channel catfish and changes in water quality of ponds and phosphorus levels in fish were measured. Higher level of (1.9%) supplementation of phosphorus in diet resulted in higher concentration of T-P and SRP in pond waters. Also it produced negative effects on fish production by lowering feed coefficient and rate of increment in body weight. Surplus phosphorus can affect fish growth and water quality of pond.

• Electronics and Telecommunications Trends
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• v.38 no.3
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• pp.29-37
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• 2023

With the increasing demand for seafood and technological advancement in aquaculture, the industry has continuously grown. On the other hand, digital twins have been actively applied to various industries. Aquaculture deals with live aquatic animals that are sensitive to growth environment management. Hence, applying a digital twin to smart aquaculture may lead to a substantial economic benefit because it enables the optimization of different variables. We analyze the status of digital twin development in agriculture. The services of the aquafarm digital twin are divided into 1) data management, 2) optimization, and 3) intelligence. Standardization related to the aquafarm digital twin is also discussed. Based on the analyses, the development stage of aquafarm digital twin is defined, and directions of technology development are suggested.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.1
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• pp.45-54
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• 2020

In this study, an automatic system for improving the working environment and increasing production efficiency of a laver aquaculture industry in Korea was developed by combining a hydraulic control system and a load cell in a current landing work of the laver. The improved gathering laver system allowed the automatic gathering process of the laver in the sea with the hydraulic control system connected to a cutting machine of the laver on the operating ship, which has been used for gathering the laver semi-automatically in a form of the traditional farming method. The transporting process of the laver from an operating ship to the land was improved as follows. A frame installed on the operating ship and the bag nets were designed and made to hold about 1,000 kg of the laver inside. The bag nets contain the laver on the improved operating ship were tied in knots and hooked on a crane using a load cell. The weight is measured immediately by lifting the bag nets through the load cell system. Weight information is communicated to the fishermen and successful bidders through the application. The advantages of the improved system can help fishermen to fish by improving their working environment and increasing production efficiency. The field survey to improve the landing operation of the laver aquaculture was conducted in Gangjin, Goheung, Shinan, Wando, Jindo, and Haenam in South Jeonnam Province. A total of 10 sites including Gunsan in Jeonbuk Province, Daebu Island in Ansan City, Jebu Island in Hwaseong City in Gyeonggi Province, and Seocheon in Chungnam Province were searched to collect data. Prototypes of the system were tested at the auction house of laver located in Goheung, where laver collection using hydraulic control and landing using road cell could be improved.

• Journal of Aquaculture
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• v.16 no.4
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• pp.252-256
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• 2003

Effluent from farm trefish contained high concentrations of nitrogen and phosphorus, such kinds of nutrients were released to the environment without proper treatment and thses increased the pollution of the environment. We evaluated the conventional treatment system with cost effective ecotechnologies for the removal of nutrients. Water lettuce chambers were investigated under the various experimental conditions to improve the efficiency of N&P removal and the treatment of from aquaculture effluent. In this research, six water lettuce chambers (80 liter each) received combination of aquaculture wastewater effluent at hydraulic retention times (HRTs) of 1, 2, 4 and 8days. The water lettuce chambers operated at a 8 day HRT investigated for aquaculture effluent (1'st) showed average removal efficiency, BOD, T-N, T-P of 92.8, 79.0 and 93.6% on average respectively.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 1992.07a
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• pp.7-19
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• 1992

Fish pathology is one of the main scientific bases upon which this expansion in aquaculture has been dependent and requires a wide knowledge of the environmental constraints, the physiology and characteristics of the various pathogens, the responses of the host and the methods by which they may be controlled. The primary disease and parasite problems in aquaculture animals relate to viral, bacterial, fungal and protozoan epizootics. Parasitic nematodes, trematodes and cestodes are commonly found in aquaculture animals, but seldom are they present in concentrations sufficinet to cause significant problems. When an epizootic does occur and chemical treatment is indicated, the appropriate chemical must be selected and properly applied. We have antibiotics, sulfa, nitrofuran and other chemicals for treatment of fish diseases. Some may be mixed with the fred during formulation, added to the pellets of feed as a surface coating, given in the dorm of an injection or used as a bath. Even though a drug or chemical has been officially approved for use in aquaculture, the substance should never be used unless there is a clear need. Some of the reasions for this view are as follows: (1) the constant use of antibiotics can lead to the development of resistant strains of bacteria, (2) biofilter efficiency may be impaired or destroyed by chemicals added to closed recirculating water systems, and (3) the injudicious use of chemicals can have a damaging effect on the environment as well as on human.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.535-544
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• 2019

To elucidate the cause of Pyropia yezoensis discoloration, the characteristics of an aquaculture environment, as well as the morphology and cell structure of P. yezoensis thallus were examined from 2011 to 2014 in aquaculture farms of the Jeonbuk province. P. yezoensis discoloration did not occur in aquaculture farms at Gaeyado located in the Geum River Estuary but occurred in aquaculture farms of Seonyudo, Munyeodo, Biando, and Docheongri near the Saemangeum embankment in November 2011 and April and November 2014. The injured leaves showed discoloration and intracellular vacuole hypertrophy. During the study period, discoloration occurred at concentrations of dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) below 5μM and 0.4μM, respectively. As a result, Pyropia discoloration was determined by low concentrations of DIN and DIP. DIN deficiency affects the early stage and low DIP concentration affects the end stage of aquaculture.

• Smart Media Journal
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• v.11 no.4
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• pp.62-68
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• 2022

To prevent the spread of disease in aquaculture, it is a need for a system to predict fish diseases while monitoring the water quality environment and the status of growing fish in real time. The existing research in predicting fish disease were image processing techniques. Recently, there have been more studies on disease prediction methods through deep learning techniques. This paper introduces the research results on how to predict diseases of Paralichthys Olivaceus with deep learning technology in aquaculture. The method enhances the performance of disease detection rates by including data augmentation and pre-processing in camera images collected from aquaculture. In this method, it is expected that early detection of disease fish will prevent fishery disasters such as mass closure of fish in aquaculture and reduce the damage of the spread of diseases to local aquaculture to prevent the decline in sales.

• Journal of Aquaculture
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• v.21 no.2
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• pp.63-69
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• 2008

We isolated complementary DNA(cDNA) encoding prolactin receptor(PRLR) from gill of black porgy Acanthopagrus schlegeli. Its PRLR cDNA consists of 1,611 base pairs and encodes the protein of 536 amino acids. To investigate the osmoregulatory abilities of black porgy in different salinities(35, 10 and 0 psu), we examined the expression of PRLR mRNA in osmoregulatory organs(gill, kidney and intestine) using reverse transcription(RT)-PCR. In gill and intestine, PRLR mRNA levels were high in 10 psu, and then decreased in 0 psu, but there is no changes in kidney. Also, plasma osmolality, $Na^+\;and\;Cl^-$ levels decreased during the experimental period. These results suggest that PRLR plays an important role in hormonal regulation in osmoregulatory organs during freshwater acclimation, thereby improving the hyper-osmoregulatory ability of black porgy in hypoosmotic environments.