• Journal of Environmental Science International
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• v.12 no.3
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• pp.307-317
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• 2003

In this study, the material cycle model was applied to suggest alternative management of water quality for Jeju Harbor. The distribution of COD, DIN (dissolved inorganic nitrogen) and DIP (dissolved inorganic phosphorus) concentrations was reasonably reproduced by simulations on the model area of the Jeju Harbor using a material cycle model. The simulations of COD, DIN and DIP concentrations were performed under the conditions of 20∼100% pollution loadings reductions from pollution sources. In case of the 100% reduction of the input loads from Sanzi river, concentrations of COD, DM and DIP were reduced to 39%, 78% and 52%, respectively at Jeju harbor. In contrast, in case of the pollutant loadings reductions from sediment, the effect of DIN and DIP reduction relatively seemed to increase around the center of study area. The 95% reduction of the pollutant loadings from river and sediment is required to meet the COD and nutrients concentration of second grade of ocean water quality criteria.

• Journal of Food Hygiene and Safety
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• v.30 no.4
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• pp.350-358
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• 2015

This study was designed to evaluate the sanitary characteristics of sea water in a part of the south coast, Korea and to check the seawater which is in compliance with the recommended bacteriological criteria for shellfish cultivation. The samples of sea water were collected at 14 sampling stations established in the survey area between March 2014 and October 2014. Food poisoning caused by seafood consumption is often associated with pathogenic microorganisms originated from fecal contamination. Therefore, fecal coliform is very important criteria for evaluating the safety of fisheries in coastal areas. The range of geometric mean (GM) and the estimated 90th percentile values of total coliform were 4.1~83.1 MPN/100 mL, and 11.7~834.1 MPN/100 mL, respectively. The GM and the estimated 90th percentile values of fecal coliform were 2.5~22.7 MPN/100 mL and 2.5~170.0 MPN/100 mL, respectively. Therefore, the bacteriological safety of seawater at this shellfish-growing area met with the Korean Shellfish Sanitation Program (KSSP) criteria for a growing area. However, the values are seasonally exceed the KSSP criteria, suggesting that the monitoring and evaluation of seawater quality is very important in shellfish-growing area.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.3
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• pp.270-276
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• 2014

Seasonal characteristics of water and sediment qualities and potential effects of the freshwater discharge from a small tide embankment interior in a coastal area in Goheung county were investigated from May to September in 2012. Chemical oxygen demand values (COD) were mostly higher than 2 mg/L in summer ebb tide, which exceed the standard value of water quality criteria II of acceptable level for aquaculture activities. Nitrogen and phosphorus were found as the limiting nutrients for algae growth in summer and fall and in spring, respectively. Nitrogen was the limiting nutrient for diatom growth in the whole studied period. The sudden high values of COD, ammonia, dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) were found in water sample collected from station 5 which located in front of the tide embankment sluice gate during spring ebb tide. The freshwater discharge form the tide embankment interior maybe affected the survey areas during a short time interval. Mean values of eutrophication index of the surveyed coastal region in spring, summer and fall were all bigger than 1. Water quality was mostly considered at level II which acceptable for aquaculture activities. Sediment quality in this study was generally in the range of standard for fisheries environment.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.125-125
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• 2003

Recirculating aquaculture systems consist of different treatment compartments that maintain water quality within the ranges of commonly recommended for fish culture. This paper presents the common considerations in designing different treatment compartments as well as the engineering criteria in designing closed recirculating aquaculture system including a circular tank for fish culture, a sedimentation basin and a foam fractionator for solids removal, two styrofoam bead filters for TAN removal, a sand filter for nitrate removal, and aerators. The main purpose is to outline a common procedure in designing of closed recirculating aquaculture system for marine fish culture.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.4
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• pp.298-306
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• 2010

A sanitary survey was conducted to evaluate the water quality and mussel (Mytilus edulis) conditions of two administrative shellfish growing waters: those designated as shellfish growing water for export, and adjacent waters on the east coast of Changseon Island, Namhae, Korea. In all, 1,656 seawater and 166 mussel samples were collected at 46 stations for seawater and five stations for the shellfish from January 2007 to December 2009. Both seawater and mussels were examined for total coliforms and fecal coliforms. The standard plate count and most probable number of Escherichia coli were also determined for the shellfish samples. The range of the geometric means and the estimated 90th percentiles of fecal coliform for seawater samples at each station were <1.8-4.1 MPN/100 mL and <1.8-22.3 MPN/100 mL, respectively. The sanitary conditions for both shellfish growing areas, the designated shellfish growing area and adjacent area in Changseon, met the 'Approved area' criteria of the United States National Shellfish Sanitation Program. The range of E. coli detected in mussels in these areas was <20-500 MPN/100 g; and only 3 of 166 samples exceeded 230 MPN/100 g, the European standard for the consumption of raw bivalves. Therefore, the mussel farms in the Changseon area are classified as 'Class A' according to criteria set in European Community regulations. However, the levels of E. coli in mussels in parts of the designated shellfish growing area and adjacent area exceeded the bacterial limits after rainfall exceeding 45 mm. Further studies are needed to fully define the conditions leading to a temporary closure to harvest after a rainfall event.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.1
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• pp.25-32
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• 2010

A Sanitary survey in an Important shellfish-growing area of Biin Bay in Seocheon-gun Korea, was conducted to evaluate bay conditions and compliance with the bacteriological criteria for areas designated for the production of shellfish for export. Seawater samples were collected monthly at 55 sampling stations established in the survey area from January 2006 to December 2008. Bacteriological water quality did not change in response to a small rainfall (10.0 mm), but it increased abruptly in response to rainfall to 62.5 mm The most probable number (MPN) value for total coliforms and fecal coliforms in 1, 980 seawater samples ranged from <1.8 to >1, 600 MPN/100mL and from <1.8 to 330 MPN/100mL, respectively. The geometric mean and estimated $90^{th}$ percentile value for total coliforms ranged from 2.0 to 10.3 MPN/100mL and from 7.0 to 42.6 MPN/100mL respectively. The geometric mean and estimated percentile value for fecal coliforms ranged from 1.8 to 4.0 MPN/100mL and from 1.9 to 18.3 MPN/100mL, respectively. Accordingly, the bacteriological water quality of Biin Bay met the National Shellfish Sanitation Program (NSSP) and Korea Shel1fish Sanitation Program(KSSP) criteria for areas designated for shellfish production for export in Korea.

• Korean Journal of Environmental Agriculture
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• v.22 no.3
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• pp.192-196
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• 2003

Objective of this study was to investigate the influences of harvest index and percolation water quality as irrigated the discharge waters from an industrial and a municipal wastewater treatment plants and seawater (1:5 seawater: tap water) as alternative water resources during tillering stage for drought stress. There were four different treatments such as the discharge water from an industrial (textile dyeing manufacture plant) wastewater treatment plant (DIWT), discharge water from the municipal wastewater treatment plant (DMWT), seawater (1:5) and groundwater as a control. For the initial chemical compositions of alternative waters, it appeared that higher concentrations of COD, $Mn^{2+}$, and $Ni^+$ in DIWT were observed than reused criteria of other country for irrigation, and concentrations of $EC_i$, Cl, and $SO_4$ in seawater were higher than that for irrigation. Harvest index was not significantly different between DIWT and DMWT with different irrigation periods in two soil types, but that of seawater (1:5) is decreased with irrigation periods in clay loam soil and not different between 10 days and 20 days of irrigation periods in sandy loam soil. For percolation water qualities, values of sodium adsorption ratio (SAR) are increased with prolonging the irrigation periods of seawater (1:5) and DIWT, but those of DMWT were almost constant through the cultivation periods regardless of the irrigation period in both soil types. EG of percolation waters is eventually increased with prolonging days after irrigation regardless of irrigation periods in both soil types. Therefore, it might be concluded that there was potentially safe to irrigate the discharge water from municipal wastewater treatment plant relative to harvest index, SAR and $EC_i$ values of the ground water through the rice cultivation period at tillering stage for drought period.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.2
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• pp.74-80
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• 2015

To assess environmental characteristics of the aquaculture area in Tongyeong, pH, dissolved oxygen (DO), dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorous (DIP) and chemical oxygen demand (COD), and acid volatile sulfur (AVS) were measured in seawater and sediment samples collected from 10 locations of Tongyeong coastal area from July to December in 2013. The quality of the seawater may be affected by seasonal variation rather than the distance from fish farm. However, sediment was contrary to seawater; the distance from fish farm may be a main factor to affect COD and AVS in sediment than season and other parameters. It is expected that contaminated organic sediments of fishery located in semi-closed bay are rapidly dispersed into surrounding waters due to fast current.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.614-622
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• 2010

The sanitary quality of a shellfish-growing area in Gangjinman, Korea, was assessed through a bacteriological examination of seawater form January 2007 to December 2009. The range of the geometric mean (GM) and the estimated 90th percentile for most-probable-number (MPN) values for fecal coliforms in samples collected in the designated area were 2.0-2.4 and 6.1-11.5 MPN/100 mL, respectively. Therefore, the bacteriological quality of seawater in the designated area in the Gangjinman area met the National Shellfish Sanitation Program (NSSP, USA) guidelines for approved areas. Also, the sanitary status of shellfish harvested from the designated area met the Korean Shellfish Sanitation Program (KSSP) fecal coliform criterion (<230 MPN/100 g). However, the degree of bacteriological contamination increased rapidly, and water quality exceeded the criteria for approved areas when large amounts of rain fell before the sampling date. Fortunately, fecal pollutants did not affect the bacteriological quality of a buffer zone established between the shoreline and the designated area. These results indicate that the current buffer zone established around the designated area protects the designated area properly.

• Ocean and Polar Research
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• v.26 no.1
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• pp.102-111
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• 2004

Recirculating aquaculture system (RAS) consists of different treatment compartments that maintain water quality within the ranges commonly recommended for fish cultures. However, common RASs still exert considerable environmental impact since concentrations of organic matter and nutrients in their effluents are high. Compared with the traditional RAS, the model RAS developed here use a sedimentation basin for digestion purposes and then use the released volatile organic matter to stimulate a denitrification process. Different treatment compartments for solids, total ammonia nitrogen, and nitrate removal have been reviewed. This paper provides the basic information on designing different treatment compartments as well as the engineering criteria in closed seawater RAS, consisting of circular tanks for fish cultures; dual drain systems, sedimentation basins and foam fractionators for removal of solids; nitrification biofilters for TAN removal; denitrification biofilters for nitrate removal; and aerators for aeration. The main purpose is to outline a common procedure in designing of closed RAS for marine fish culture with an emphasis on easy management and low expense, as well as reduction of the environmental impact.