• Journal of Aquaculture
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• v.18 no.4
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• pp.272-279
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• 2005

The efficacy of lidocaine hydrochloride and Clove oil as anaesthetics was evaluated in the Korean rose bitterling, Rhodeus uyekii (Mori, 1935) and oily bitterling, Acheilognathus koreensis (Kim and Kim, 1990) at four different temperatures of $10^{\circ}C,\;15^{\circ}C,\;20^{\circ}C$ and $25^{\circ}C$. When complete anaesthesia was acquired less than 3 min and recovery was acquired less than 10 min, the optimal dose range of lidocain hydrochloride at $20^{\circ}C$ was 250${\~}$550 ppm in Korean rose bitterling, and 150${\~}$550 ppm in oily bitterling, respectively. In case of Clove oil, the optimal dose range at $20^{\circ}C$ was 40${\~}$200 ppm in Korean rose bitterling and 80${\~}$240 ppm in oily bitterling, respectively. Both of lidocaine hydrochloride and Clove oil resulted in a negatively dose-dependent manner for anaesthesia induction time in these two species. Recovery times were more variable in relation to anaesthetic doses, but in general higher anaesthetic doses resulted in similar or longer recovery time. As expected, the lower temperature resulted in longer anaesthesia induction and recovery time. The study demonstrated that lidocaine hydrochloride and Clove oil can be used as effective anaesthetics in these two species. The results from this study could be useful for aquaculturists industry and other related husbandry practices that require anaesthesia of Korean rose bitterling and oily bitterling.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.4
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• pp.55-63
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• 2007

The Group Digital Surveillance System for Fishery Safety and Security (GDSS-F2S) is to provide the target tracking information and the target identification information in order to secure an huge aquaculture farm-field from a thief. The two information, however, is not enough to indict the thief due to the lack of lawful evidences for the crime actions. To overcome this problem, we consider the target image information as one of solutions after discussion with the effective countermeasure tools for the crime actions with scenario-based analysis according to the geological feature of aquaculture farm-field. To capture the real-time image for the trespassing targets in the aquaculture farm-field area, we developed the image capture system which is consists of ultra sensitive CCD(Charge-Coupled Device) camera with 0.0001 Lux and supplementary devices. As results from the field tests for GDSS-F2S with image capture system, the high definite images of the vehicle number plate and shape, person's actions and features are obtainable not only day time but also very dark night without moon light. Thus it is cleary known that the improved GDSS-F2S with image capture system can provide much enough lawful evidences for the crime actions of targets.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.2
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• pp.104-115
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• 2014

Abundance and composition of marine debris on 13 beaches of Tongyeong City, South Korea were surveyed in 2013 Autumn. The average quantity of macro debris (>25 mm) was about 30 particle/$m^2$ and that of micro debris (1 mm-25 mm) was about 26,971 particle/$m^2$. This is a very high level compared with other areas of South Korea and the other countries. Among the 7 material types of debris (styrofoam, hard plastic, fiber, metal, glass, wood and others), styrofoam composed a large portion: 75% of macro debris and 98% of micro debris. And among the 'whole' styrofoam debris items whose original volume is remained more than 50%, styrofoam buoy debris composed 93%. This result suggests that the beaches surveyed are seriously contaminated by marine debris, and most of its sources are aquaculture styrofoam buoys. Management of styrofoam buoy debris used for oyster aquaculture in Tongyeong City is important not only for Tongyeong city, but also for other areas, because Tongyeong city hosts the biggest number of oyster aquaculture areas in South Korea.

• Ocean and Polar Research
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• v.33 no.4
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• pp.435-445
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• 2011

We investigated geochemical properties, and microbial sulfate- and iron(III) reduction in sediment influenced by the aquaculture of abalone in the Nohwa-do, southern coastal sea in Korea. Concentrations of ammonium, phosphate, and sulfide in the pore-water were higher at farm sites than at control sites. The differences between the 2 types of sites were most apparent in terms of the weights of abalone and the temperature increase during September. Accordingly, the rates of sulfate reduction at the farm sites during September (61 mmol S $m^{-2}d{-1}$) were 3-fold higher than the sulfate reduction during May (20 mmol S $m^{-2}d{-1}$). In contrast, Fe(III) reduction rates were highest at the control sites in May, but its significance was relatively decreased at farm sites during September when sulfate reduction rates were highest. During September, benthic ammonium flux was 3-fold greater at the farm sites (35 mmol N $m^{-2}d{-1}$) than at the control sites (12 mmol N $m^{-2}d{-1}$), and phosphate flux was 8-fold higher at the farm sites (0.018 mmol P $m^{-2}d{-1}$) than at control sites (0.003 mmol P $m^{-2}d{-1}$). Overall results indicated that the inappropriate operation of a large-scale aquaculture farm may result in excess input of biodeposits and high nutrient fluxes from the sediment, thereby decreasing diversity of the benthic ecosystem and deepening eutrophication in coastal waters.

• Journal of Aquaculture
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• v.20 no.4
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• pp.226-231
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• 2007

We investigated survival and osmolarity, oxygen consumption, amonia extetion and filtration rates associated with physiological responses of the tunicate Halocynthia roretzi salinity changes. Acclimation times for osmolatity in different salinities took $20{\sim}26$ hours in 60% SW (19.8 psu) and $20{\sim}25$ hours in 80% SW (26.4 psu), while their times took $7{\sim}8$ hours in 110% SW (36.3 psu). Accordingly, acclimation times for high salinities were faster than those for low salinities. Survival (%) was more than 80% at salinity over 26.4 psu, and 6 $days-LS_{50}$ was 25.4 psu. physiological responses such as oxygen consumption, amonia excretion and filtration rates of H. roretzi showed more clear reactions in the longer exposure period (four days after exposure) than that in the beginning of the exposure. To sum up the results, the tunicate might be stressed from the beginning of the exposure in low salinity.

• Journal of Sensor Science and Technology
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• v.30 no.3
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• pp.154-164
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• 2021

In this study, the IoT sensor technology required for improving the survival rate and high-density productivity of individual shrimp in smart shrimp farming (which involves the usage of recirculating aquaculture systems and biofloc technology) was analyzed. The principles and performances of domestic and overseas water quality monitoring IoT sensors were compared. Furthermore, the drawbacks of existing aquaculture monitoring technologies and the countermeasures for future aquaculture monitoring technologies were examined. In particular, for farming white-legged shrimp, an IoT sensor was employed to collect measurement indicators for managing the water quality environment in real-time, and the IoT sensor-based real-time monitoring technology was then analyzed for implementing the optimal farming environment. The results obtained from this study can potentially contribute to the realization of an autonomous farming platform that can improve the survival rate and productivity of shrimp, achieve feed reduction, improve the water quality environment, and save energy.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.4
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• pp.365-371
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• 2003

The reared fries of black sea bream, Acanthopagrus schlegeli were released in Gamak Bay and initial adaptation to the environment was evaluated. Thirty thousand fries were marked with magnetic tag, released and recaptured and its stomach content were analysed; the neighboring zooplankton, beuthic algae and other young fishes were investigated. The fries were released on July 30, 2001 in summer season. Water temperature of surface and bottom were $24^{\circ}C\;and\;21^{\circ}C,$ respectively. $Chlorophyll\;\alpha$ content was 4.5 ${\mu}g/L$ with high primary production. Salinity was $32.0-32.5\%_{\circ}.$ Water depth of releasing site was about 30 m. The sea jungle was formed at the first point of releasing and it kept the fries for about 3 days in the bay with plenty of food organisms within 5 m depth. Stomach analysis of the fries revealed that real feeding started from the 15 days after releasing and full feeding took place after the tenth day.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.5
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• pp.622-629
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• 2014

This study induced biological denitrification and nitrification via a biofiltration process with the view of removing nitrogen from land-based fish farm effluent. To achieve this, we operated an aquaculture nitrogen-removal system that includes a denitrification and nitrification reactor [working volume 40 L, flow rate 64.8 L, HRT (hydraulic retention time) 14.8 h, HRT considering recycling of NOx 7.4 h]. In the continuous process, the nitrification rate of ammonium nitrogen exceeded 90% at a steady state and the denitrification efficiency exceeded 80% with recycling to a pre-anoxic reactor. In addition, the pH in the final effluent was lower with a low influent water alkalinity averaging 100 mg/L (as $CaCO_3$). For effective denitrification reactions, carbon must be supplied via particulate organic matter (POM) hydrolysis because of the low C/N (carbon/nitrogen) ratio in the water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.337-342
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• 2016

Sea cucumbers have been an important part of human diets throughout history; demand is increasing every year, making the species a target for coastal resource development. New harvesting technologies have been developed in response to demand, including nursery production and insemination aquaculture, but such methods produce relatively few individuals and productivity per unit area is very small. For example, captures are prohibited during July and August due to the breeding season, and sea cucumbers aestivate during the hot season and hibernate during the cold season, all factors that limit natural-environment production in Korea. Problems with slow growth of sea cucumbers have been encountered in previous rearing experiments. To assess the importance of feeding ecology on sea cucumber growth, we conducted pond-bottom and lantern-net culture experiments. Results showed that sea cucumbers in bottom cultures grew from 3.06 to 102.59 g, but those in lantern cultures only grew from 25.60 to 28.03 g.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.7
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• pp.157-164
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• 2020

As the consumption of fishery products continues to increase, aquaculture industry has emerged instead of fishing industry facing limitations of fish stock resources. Recently, smart fish farming industry has rapidly developed through convergence with 4th Industrial Revolution technology. Accordingly, it is important to derive a future model of smart fish farming platforms in order to secure the superiority of the aquaculture industry and the technology standard hegemony. In this study, the future direction of smart fish farm platform was derived through the analysis of environment related to politics, economy, society, and technology related to smart fish farming by applying PEST methodology of macro-environment analysis. It is expected that it will help the public and industrial circles in planning and implementing related projects by including the entire process of value chain of aquaculture industry of breeding, production, management and distribution, and by presenting advanced models based on artificial intelligence and digital twin.