• Journal of fish pathology
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• v.23 no.3
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• pp.379-388
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• 2010

This paper presents a computer program for easy and rapid disease diagnosis of olive flounder diseases. To design the program, standard diagnosis process of the 14 olive flounder diseases was first setup, then implemented four-steps diagnosis program. To run program, first input fundamental information such as water temperature, size of the diseased fish. Then sequentially, three categories of key factors for disease diagnosis which include external clinical signs, internal clinical signs and microscopic observations are selected. When a user selects the observed signs of olive flounder from the listed options, the program provides maximum 5 presumed disease candidates in order. The disease information, treatment and prevention methods are provided by connected web server through internet. The program would support fish doctors and farmers by providing easy and rapid diagnosis of diseased olive flounder.

• Fisheries and Aquatic Sciences
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• v.25 no.3
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• pp.151-157
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• 2022

Various approaches have been applied to transform aquaculture from a manual, labour-intensive industry to one dependent on automation technologies in the era of the fourth industrial revolution. Technologies associated with the monitoring of physical condition have successfully been applied in most aquafarm facilities; however, real-time biological monitoring systems that can observe fish condition and behaviour are still required. In this study, we used a video recorder placed on top of a fish tank to observe the swimming patterns of rock bream (Oplegnathus fasciatus), first one fish alone and then a group of five fish. Rock bream in the video samples were successfully identified using the you-only-look-once v3 algorithm, which is based on the Darknet-53 convolutional neural network. In addition to recordings of swimming behaviour under normal conditions, the swimming patterns of fish under abnormal conditions were recorded on adding an anaesthetic or lowering the salinity. The abnormal conditions led to changes in the velocity of movement (3.8 ± 0.6 cm/s) involving an initial rapid increase in speed (up to 16.5 ± 3.0 cm/s, upon 2-phenoxyethanol treatment) before the fish stopped moving, as well as changing from swimming upright to dying lying on their sides. Machine learning was applied to datasets consisting of normal or abnormal behaviour patterns, to evaluate the fish behaviour. The proposed algorithm showed a high accuracy (98.1%) in discriminating normal and abnormal rock bream behaviour. We conclude that artificial intelligence-based detection of abnormal behaviour can be applied to develop an automatic bio-management system for use in the aquaculture industry.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.4
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• pp.492-502
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• 1995

This paper describes the relationship between the behavior of the snakehead ( Channa arps) of 44cm long and the environmental noise levels due to the piling work. The experiment is conducted in the aquafarm located near Asan lake, Pyongtaek in 1993. The fish trajectory is obtained by a biotelemetry system in which a pulsed ultrasonic pinger attached onto the dorsal is tracked three dimensionally, and the noise and the vibration levels both in air and in water are measured. The results of this study are as follows: 1) The noise levels in water and in air and the vibration level measured at a distance of 90m from the noise source, increased by 36.5dB $(re\;l{\mu}Pa)$, 2308$(re\;0.0002{\mu}bar)$ and $5.9{\mu}m$ repectively compared to the levers before piling. 2) The highest variation of the swimming speed was observed right after the piling works and the width of variation decreased with the elapsed time. The average speeds of the fish before and during the works were measured as 0.8 times and 1.1 times of the body length, respectively. 3) It is found that the fish escapes into the mud of the aquafarm when a heavy shock wave occurred. Consequently, the heavy shock by the piling works could produce a considerably unfavorable effect to the fish.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.3
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• pp.785-798
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• 2017

This study was conducted to evaluated the surface(10 variables) and bottom(10 variables) water quality, and sediment(3 variables) in the cage fish farm off Baegyado in Gamak Bay using a multivariate analysis from January 2013 to November 2014. Generally, the environmental data did not show a certain tendency by months during two years investigated. The pairwise simple correlation matrices among variables were also shown. The first four principal components of the surface water in 2013 explain 93% of the total sample variance; the first principal component($z_1$) showed the freshwater inflow and/or precipitation, $z_2$, $z_3$ and $z_4$ related to freshwater inflow and/or precipitation, organic matters and eutrophy, respectively; the first four principal components of the bottom water in 2013 explain 93% of the total sample variance; the $z_1$, $z_2$ and $z_4$ related to freshwater inflow and/or precipitation, and $z_3$ water temperature. In 2014, at the surface water the first three principal components explain 87%; the $z_1$, $z_2$ and $z_3$ related to water temperature, eutrophy and freshwater inflow and/or precipitation, respectively; at the bottom water the first three principal components explain 93%; $z_1$, $z_2$ and $z_3$ related to water temperature, freshwater inflow and/or precipitation and eutrophy. Half of the principal components related to freshwater inflow and/or precipitation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.4
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• pp.273-282
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• 1994

This paper describes about the behavior of the lseraeli carp (Cyprinus cartio. body length 43cm) and the Red seabream (Chrysophrys major. body length 35cm) aquacultured by telemetry techniques. The telemetry system consists of a pinger of 50kHz, three omni-directional hydrophones and ultrasonic receivers, a single board computer for the signal processing, two RF transceivers for the data communication, and a personnel computer. Those fish tagged the pingers were tracked by the LBL method, and its location was calculated by the hyperbolic method. The average speed of the lsraeli carp was about 1.0 times of the body length in a farming water tank (24$\times$24$\times$1m), and the Red seabream 1.3 times of the body length in a farming raft (10$\times$10$\times$5m). A variation of the speed of the lsraeli carp was higher than the other one.

• The Journal of Fisheries Business Administration
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• v.49 no.4
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• pp.19-36
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• 2018

Overstock in aquaculture is a matter of concern in aquaculture management. To sort fish based on fingerling size in case of overstocking is an important problem in aquaculture farm. This study aims to determine the amount of fry overstock and sorting time in aquaculture farm. This study builds a mathematical model that finds the value of decision variables to optimize objective function summing up the fingerling purchasing cost, aquaculture farm operating cost and feeding cost under mortality and farming period constraints. The proposed mathematical model involves following biological and economical variables and coefficients: (1) number of fingerlings, (2) sorting time, (3) fish growth rate and variation, (4) mortality, (5) price of a fry (6) feeding cost, and (7) possible sorting periods. Numerical simulation is presented herein. The objective of numerical simulation is to provide decision makers to analyse and comprehend the proposed model. When extensive biological data about growth function of fry becomes available, the proposed model can be widely applicable to real aquaculture farms.

• Journal of Navigation and Port Research
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• v.34 no.1
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• pp.77-82
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• 2010

These days our coasts have been damaged by the polluted water resulting from the construction of industry on the shore, increasing population and urbanization. The destruction of ecosystem has induced many problems to aquaculture such that it raises the production cost of aquatic products for eating. For solving these problems aquafarm has been moving to the land. This paper intends to describe the automatic feeding system for the inland fish farm. An existent automatic feeding system has problems such that feed quantity is not accurate and feed itself is broken by feed motor. But a proposed system in this paper is more accurate than the existent system in view of feed quantity by using the combination of valve and load-sell. Resultantly, the system can safely transfer feed to inland nursery tank. Through several experiments using a real system, the effectiveness of the proposed system is verified under all conditions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.730-733
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• 2010

The Green Lamp Fixture (GLF) of LED prepared with thin panel structure was investigated for illumination of street lamps and other lighting system uses, which was also very useful to aquaculture and aquafarm lighting uses, or fish luring lights and marine aquanautics of aquamarinautics (aquamarine+aquanautics) uses, etc. In the case of fish luring lights, it was verified that the fish luring of Green Lamp Fixture of LED was very effective for phototaxis movement and ecological community promotion to the micro-living things of organisms and the small fries and fishes, like as 'crowding together'. For the aquaculture lightings, it was also very excellent in waterproof and heat-sink properties, photosynthetic growing of algae and micro-organisms, water-weeds and seaweeds living underwater.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.533-540
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• 2022

We evaluated a worm-based extruded pellet diet with black soldier fly Hermetia illucens larvae (BSF) meal and BSF oil for olive flounder Paralichthys olivaceus through field feeding experiments at a commercial aquafarm. We prepared two experimental diets by replacing fish meal and fish oil with BSF meal and BSF oil (BEP-1, BSF meal 7%, BSF oil 1%) and (BEP-2, BSF oil 2%), respectively. We prepared raw-fish based moist pellets (MP) for comparison between the two experimental diets. We distributed the olive flounder (220±6.29 g) in square (10 m×10 m×1 m) concrete, 100 ton tanks at a density of 1,600 fish per tank (n=3) in triplicate for each dietary treatment. We fed the diets to the fish to apparent satiation for 7 months. At the end of the feeding trial, we found no substantial differences between the groups in terms of growth performance, survival, or feed utilization. None of the diet groups showed any changes in either hematological or non-specific immune responses. The histological observation of the intestine showed that the goblet cell number and cholecystokinin-producing cell activity increased in the fish fed the BEP diet compared with the those of the fish fed the MP diet. These results indicated that dietary BSF meal and oil can be used for olive flounder without compromising growth or, hematological and histological parameters.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.5
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• pp.725-732
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• 2020

The sudden drop of water temperature in winter is very threatening factor that affects the productivity of farmed fish and the management in aquafarm. In this study, we investigated the effect of low temperature on the survival, oxygen consumption and stress responses of parrotfish Oplegnathus fasciatus due to acute drop of water temperature. The survival rate of parrotfish Oplegnathus fasciatus was 5% at 6℃, 95% at 8℃ and 100% at 10℃ on the 4^th day of exposure in each experimental temperature. Low-lethal temperature for 4days of parrotfish Oplegnathus fasciatus (4 day-LT₅₀) was 6.99℃ (confidence limit, 6.55-7.42℃). Oxygen consumption rate was significantly decreased with decreasing water temperature. Temperature coefficient (Q₁₀) was found to be 4.0 between 10℃ and 8℃ and 0.39 between 8℃ and 6℃. As a result of investigating the stress response according to the drop in water temperature, the concentration of SOD (Superoxide dismutase), cortisol, glucose, total Ig, AST (Aspartate) and ALT (Alanine aminotransferase) increased with decreasing of water temperature. This study would be useful for the management of temperature about cultured fish.