• Journal of Korean Society of Environmental Engineers
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• v.33 no.7
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• pp.492-500
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• 2011

Antibiotic resistant microbes were isolated in catfish, trout, eel and loach aquaculture effluent. The distribution of antibiotic resistant microbes in aquaculture effluent and the disinfection efficiency of antibiotic resistant microbes by electron beam irradiation were investigated. It was shown that the multi-drug resistant bacteria were Aeromonas sp., Citrobacter sp., Bacillus sp., Marinobacter sp., Pantoea sp., Pseudomonas sp. and Enterobacter sp. in aquaculture effluent. 41.7% of total strains showed the resistance against one antibiotic agent, and 58.3% of total strains showed the resistance against more than two antibiotics. It was evidently shown that the toxicity and physicochemical properties of antibiotics can be estimated using Quantitative Structure Analysis Relationship (QSAR). Electron beam irradiation was very effective for the disinfection of antibiotic resistant bacteria from aquaculture effluent, in which the disinfection efficiency was approximately 99.9% with electron beam of 1 kGy.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.1
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• pp.127-142
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• 2023

The management of size and weight, which are the growth information of aquaculture fish in fish-farms, is the most basic goal. In this study, the epoch is defined in fish-farms from the time of stocking or dividing to the time of shipment, and the growth data for a total of three epoch is analyzed from a time series perspective. Growth information such as the size and weight of aquaculture fish that occur over time in fish-farms is compared and analyzed with water quality environmental information and feeding information, and a model is presented using the analysis results. In this study, linear, exponential, and logarithmic regression models are presented using the Box-Jenkins method for size and weight by epoch using data obtained in the field.

• Explosives and Blasting
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• v.28 no.2
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• pp.86-98
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• 2010

As the quality of life is being upgraded, the public complaints about noise and vibration from construction sites are growing. Despite the disputes over the blasting damage on aquatic lives in river, ocean, and aquarium near construction sites tend to increase, most of existing solutions or regulations on the damages caused by blasting are established for the damages on land. Although the estimated amount of damage is up to several millions of USD, there is no guideline for resolving the dispute related to the underwater vibration. This paper presents an example where the public grievance about the underwater noise was successfully resolved by elucidating the characteristics of underwater sound, deducing the correlations between ground vibration and underwater sound during blast, and predicting the underwater sound level during blasting from the ground vibration measured on the ground near an aquarium basin.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.908-913
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• 1998

The productivity of land based seawater fish farm has been decreased because of unexpected outbreaks of diseases caused by the contaminated inlet seawater. Sometimes unfiltered/untreated outlet seawater from the land based seawater fish farm has created serious environmental problem. In the needs of treatment systems for the inlet and outlet seawater, the researchers have developed two different systems, The purpose of this study is to design and test two treatment systems, the screen filter for inlet seawater and drum filter for outlet seawater, on the basis of concept of system design and automatization. After developing two systems, an experiment has been conducted with two systems and collected data to improve design and efficiency of the system. In this study, detailed design and efficiency of the system could be improved by the programmable logic controller (PLC).

• Journal of fish pathology
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• v.8 no.2
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• pp.91-98
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• 1995

During 1993 and 1994, some mortalities of flounder(Paralichthy olivaceus) fry were recorded in several fish farms and viruses were isolated from 3 of the farms. Electron microscopic examination revealed that the virus particles were hexagonal and unenveloped with an average diameter of 50 to 55nm. Serological and molecular properties of these isolates were examined. The viral RNA and polypeptides patterns on electrophoresis, as well as neutralization test results, showed that these isolates were birnaviruses and two were closely related to infectious pancreatic necrosis virus(IPNV) serotype AB and one was to IPNV serotype SP. This is the first isolation of birnaviruses from marine fish in Korea.

• Journal of fish pathology
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• v.27 no.1
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• pp.77-83
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• 2014

The monitoring was performed to survey the mortalities and medications occurred in the inland aquaculture farms of olive flounder in South Korea from May to October, 2012. Both of the indirect inquiry for entire inland farms and the sample survey for selected farms were carried out. The aquatic organism disease inspectors, who have the national licenses for the diagnosis and prevention of aquatic organism diseases and have close relationship with the farms, investigated the rates and causes of mortalities according to the standard manual. The cumulative mortalities rate by the indirect inquiry on 565 farms, was calculated to 27.18%, and the mortalities rate by infectious diseases was 22.64%. Otherwise, the mortalities rate by sample survey on 60 farms was 25.50%, 19.33% of them were caused by infectious diseases. The high mortality rates were recorded by scuticociliatosis, non-infectious loss, streptococcosis, VHS, artificial eliminations, vibriosis and gliding bacterial disease. Streptococcosis and non-infectious mortality caused to serious loss in productivity and economy of the farms, because of their outbreaks in the flounder groups over 600 g. The monitoring of medications in the selected farms revealed that formalin for the treatment of external parasites, such as scuticociliates, was the most commonly used drugs in the farms. As the antibiotic medications, amoxicillin and florfenicol for streptococcosis, and oxytetracycline and neomycin expecting wide antibacterial spectrum, were frequently prescribed.

• Journal of Wetlands Research
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• v.9 no.2
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• pp.71-84
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• 2007

Masan Bay is a representative semi-closed bay acted as a sedimentation reservoir with a slow current velocity and a poor water circulation in Korea. The pollutants from terrestrial sources into the Masan Bay have apparently environmental pollution problems, such as eutrophication, red tied, and hypoxia. In this study, An ecological modeling work was performed to estimate the material circulation including the growth of bivalve in ecosystem. Furthermore, the effect of water purification was calculated by filter feeding bivalve to particulate organic matter just like COD and phytoplankton. And Water quality management strategy by bio-purification of bivalve is derived through selection of location, quantification of bivalve aquaculture farm. The results showed that the optimum location for bivalve farming is where phytoplankton accumulation by physical processes is maximized and the optimum density and area of bivalve are 35 individuals $m^{-3}$ and ca. 500 hectare, respectively. When assuming conditions for the optimum growth of bivalve, COD could decrease by up to 18% even without other reduction of pollution loads.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.3
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• pp.250-256
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• 2017

This study investigated the removal efficiency of organic matter and nitrogen from fish farm effluent by hydraulic retention time (HRT) using an upflow biological filter (ANR system) reactor. The recycling time and influent flow in the reactor were controlled to 14.8, 7.4, 5.5 and 3.2 h to evaluate HRT. In addition, each reactor was coupled to a fixed bed upflow filter charged with media. The results showed that removal efficiency was ${\geq}95%%$ with an HRT of 5.5 h, and nitrification efficiency was reduced to 81% with an HRT of 3.2 h, although nitrification efficiency temporarily decreased due to the shock load as HRT decreased. Total nitrogen removal rate was also reduced to about 65% with an HRT of 3.2 h, which was considered a washout effect of nitrifying and denitrifying microorganisms by increasing the shearing force to the filter media, which decreased organic matter and nitrogen removal efficiency.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.113-116
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• 2006

Successful field test results for detection of buried undersea HVDC by magnetic vector measurements are discussed. Further study will be focused on practical utilization.

• Journal of Wetlands Research
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• v.22 no.2
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• pp.59-65
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• 2020

The purpose of this study is to determine the origin of organic matter on sediment at Sindu-ri tidal flat. Grain size, organic matter, C/N ratio and the 13C and δ15N ratio were measured at three stations (Stn. A, B, C) of the tidal flat. As a result, the spatial variation in sediment properties showed that organic matter was related positively to the sediment mud content. Organic matters originating from marine particulate organic matter (marine POM) and fish farm particulate organic matter (fish farm POM) showed sedimentation of organic matters at Stn. A, sandy tidal flat, though terrestial plant (TP) and benthic microalgae (BMA) did at Stn.C, muddy tidal flat. Meanwhile, Stn. B, the intermediate property of Stn. A and C, was affected by marine POM and BMA. Furthermore, it was revealed that the amount and origin of organic matters in the sediments depended on spatial variation, and the factors were different from the stations. Particularly, at the Stn. C, the sediment showed high concentration of TOC in terrestrial organic matter and smaller size particles (< 63 ㎛). These facts suggest the many small size particles and organic matter will affect the sediment environmental condition in the Stn. C.