• Korean Journal of Environmental Biology
• /
• v.36 no.1
• /
• pp.90-97
• /
• 2018

This study assessed the effect of ozone to control pathogenic bacteria in inlet water flowing to flounder farms, establishing operational parameters of ozonation at seawater conditions. Hydraulic retention time in a reaction pipeline after ozonation was fixed at 3 minutes in a flow through system. Concentrations of total residual oxidant (TRO) by ozonation were measured according to different ozonation intensities. The oxidant reduction potential (ORP), which is indirect but enables real-time measurement, was measured in relation to TRO values. TRO values were $0.01{\pm}0.01mg\;L^{-1}$ at an ORP range of 320-410 mV, $0.07{\pm}0.02mg\;L^{-1}$ at 600 mV, and $0.16{\pm}0.03mg\;L^{-1}$ at 700 mV. A heterotrophic marine bacteria colony was reduced by 80.6-97.9%, showing the suppression effect of ozonation on total bacteria in inlet water. At an ORP range of 400-500 mV, colonies of heterotrophic marine bacteria, Vibrio spp., and gram negative bacteria were significantly reduced in outlet water from a culture tank with ongrowing flounder (230 g) at a stocking density of $8kg\;m^{-2}$. Especially, Vibrio spp. and gram negative bacteria were seldom found at 400-500 mV. The daily feeding rate was from over 0.7% to total body weight at 300-500 mV, showing better performance than that in the control. The pathogenic bacteria entering the flounder farm were effectively removed when the ORP range to 400 mV or less.

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

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.20 no.4
• /
• pp.328-340
• /
• 1987

In order to clarify major reasons of a poor harvest, the Porphyra-cultivation ground was investigated in Kwangyang Bay in terms of the laver production per unit area, diseases, and fouling organisms from January to April in 1986. The laver production per unit area of the control station was more than that of the study area at 'Soppal' cultivation ground, while the difference at the cultivation groud using 'nets' seemed to be insignificant. The vertical attachment range of laver was directly associated with the production per unit area at 'Soppal' cultivation ground. The number of young thalli of 1-3 mm length was almost similar between control and study sites at 'nets' cultivation ground. Two kinds of diseases in cultured laver, the crape and shot hole, were prevalent during the study period. However, the affected thalli were gradually decreased at the end of the study period. Major fouling organisms attached to 'Soppal' were Balanus albicostatus, Enteromorpha prolifera, Capsosiphon fulvescens, and Scytosiphon lomentaria. In conclusion, the poor harvest of laver in 1986 may result from such following problems as the decrease in vertical attachment range of laver and fouling problems as the decrease in vertical attachment range of laver and fouling organisms at 'Soppal' cultivation ground, prevalence of certain diseases, changes in environmental conditions, arrangement and maintenance of facilities for laver cultivation.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.21 no.5
• /
• pp.484-491
• /
• 2015

The productivity of Manila clam(Ruditapes philippinarum) aquaculture farm is closely related to suitable site selection, so it is essential to assess the habitat suitable for aquaculture species in order to manage yield. This study evaluated the habitat suitable index(HSI) with 9 sites for tidal flat farm, Gochang(Hajun) on May 2014. The suitability index was selected Growth(hydrodynamics, chlorophyll a), Survival(sediment-sand, silt-clay) and Water Environment(dissolved oxygen, salinity). Both Weight and No weight were tried for objective judgment as HSI scoring method. As a result, it shows lower tidal flat(HSI; No weight: 0.60~0.76, Weight: 0.47~0.70) is higher than upper(HSI; No weight: 0.25~0.27, Weight: 0.09~0.10), hydrodynamics and sediment particle size are the most effective. This research can consider the potential suitable site for Manila clam through scientific approach, and provide the basis for optimal management practices in tidal flat farm.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.7 no.3
• /
• pp.90-98
• /
• 2004

This paper illustrates some practical geographic information system (GIS) applications for aiding fishery managers and coastal area planners in analysing the likely control scheme of coastal farming areas, and in providing a flexible framework for decision making on fishery development and zoning issues. The effective management of marine farming operation is vitally important since it can greatly influence economic availability by determining capital outlay and by affecting running costs, rates of productions and mortality factors. GIS has been widely adopted elsewhere as a potent management tool in both the private and public sectors. GIS is now being extensively adopted in marine-associated activities. Here, we have used GeoMania v2.5 GIS software and its 3D Analyst extension module to visualize marine farming areas data that were collected around the Jinhae bay.

• Proceedings of the KSRS Conference
• /
• 2001.03a
• /
• pp.9-14
• /
• 2001

오랜 기간동안 진행되는 사회간접자본 건설의 진행 상황을 관측하는 것은 대규모 공사의 종합적인 관리를 위해 필수불가결한 요소이다. 동북아 지역의 중추 공항 기능을 담당할 영종도 국제공항의 공사진행 과정을 관측하기 위하여 인공위성 영상 자료가 활용되었다. 바다위에 건설되는 공항의 특성으로 인하여 방조제 건설과 매립공사가 수행되었다. 활주로, 유도로, 여객터미널과 복합교통센터 등이 건설되었으며, 공항의 건설로 산림이 훼손되고 양식장과 염전이 매립되는 것이 관측되었다. 이러한 공항공사의 진척상태를 분석하기 위해서 시계열 Landsat TM 영상을 사용하였으며, 타 위성영상에서는 공항의 공사현황이 어느정도 분석가능한지를 가늠하기 위해서 KOMPSAT EOC, IRS-1C PAN, RADARSAT SAR 영상이 활용되었다. 시계열 Landsat TM 영상에서는 공항 부지의 매립 진척 현황과 산림의 벌채 등을 잘 분석할 수 있었다. KOMPSAT EOC 과 IRS-1C PAN 영상은 높은 공간해상력으로 건설에 사용된 가건물과 같은 세부적인 시설물을 관측할 수 있었다. 15m PAN 영상을 제공하는 Landsat ETM은 IHS 합성 후 분석하였는데, 기존의 TM 영상에서 분류하지 못했던 방조제의 도로와 성토를 구분할 수 있었다. RADARSAT SAR 영상에서는 광학영상에서 볼 수 없었던 독특한 정부 를 얻을 수 있었다.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2000.05a
• /
• pp.520-521
• /
• 2000

큰구슬우렁이 (Glossaulax didyma)는 복족강 (Gastropoda), 중복족목(Gastropoda), 구슬우렁이과 (Naicidae)에 속하고 내만의 조간대에서 수심 10m 가까이의 진흙과 모래가 섞인 조하대애 묻혀 살며 일본과 우리나라 전역에 분포한다 (유, 1976). 큰구슬우렁이는 이매패나 복족류의 껍질에 구멍을 뚫어 섭식하는 육식성패류로 패류양식장 등의 해적생물로 알려져 있다 (유, 1976). 그러나 이들은 식용으로 이용되고 있어 지방에 따라 배꼽고둥, 배꼽, 우렁이, 잠빼기, 말띠, 미소라, 개소랑, 명지고둥, 가내기, 해구 등으로 폭넓게 불려진다. 이와 같이 식용으로 널리 이용되고 있는 큰구슬우렁이는 산업종으로 중요한 위치에 있어 자원관리적 측면에서 이들의 생식생물학적 조사가 조속히 이뤄져야 할 종이다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.10a
• /
• pp.293-294
• /
• 2001

전복류는 옛날부터 고급수산품으로서 가치가 높고, 근년에 와서는 경제성장과 함께 그 수요가 날로 증가되는 추세로 양식 대상종으로 전망이 밝다(변 등, 1984, 김, 1997). 전복양식은 최근 연안환경의 오염으로 인한 양식장 적지의 제한 등의 여러 가지 문제점의 제기로 종묘생산과 양성에 이르기까지 육상 수조에서 완전양식이 시도되고 있는 추세이다. 육상수조식 양식은 전 사육과정을 인위적으로 관리 하면서 사육하기 때문에 생존율 및 성장효과 면에서는 다른 양식 방법보다 유리하다는 이점을 가지고 있지만, 전복이 한정된 공간에서 대량으로 사육됨에 따라 여러 가지 질병과 수질악화, 여름철 고수온기 때의 수온의 급상승이나 적조 생물 및 이상수괴에 의한 치패의 성장저하 대량 폐사 등의 문제점을 가지고 있다. (중략)

• Journal of the Korea Society for Simulation
• /
• v.19 no.2
• /
• pp.43-49
• /
• 2010

Form, increasing the income of fishermen and internationally competitive high value-added seafood merchandising consumers for the purpose of improving the reliability of the food as do Tongyeong Gyeongsangnam-piping of the high quality marine products traceability system for farm businesses. Real-time traceability of the seafood supply chain to manage RFID technologies and related IT technology was introduced in progress. In this study, real-time traceability of fish introduced to the features of RFID technology and to recognize its effects. And efficient distribution system of fish suggests ways to improve and execute simulation about supply chain.

• Proceedings of the KSRS Conference
• /
• 2006.03a
• /
• pp.79-82
• /
• 2006

조간대 지형의 발달과 변화에 대한 이해는 물순환 모델, 양식장 관리, 전자해도의 갱신, 연안개발 계획수립, 항로의 효율적 관리, 선박 안전항해, 상륙 작전 등에 있어서 매우 중요하다. 기존의 조간대 DEM 을 만드는 방법 중 위성영상을 이용한 waterline 방법과 선박을 이용한 음향측심(echo sounding) 방법이 있다. 이 연구의 목적은 위성 원격탐사 자료와 음향측심기 자료를 함께 사용하여 각각의 방법의 단점을 보완함으로서 조간대 DEM 의 정밀도를 향상시키는 것이다. 천수만 황도 조간대에 대해 음향측심에 의해 얻어진 자료를 관측소 조위와 단위를 일치시킨 후 광학위성으로부터 추출된 waterline 자료와 합성하여 DEM 을 제작하였다. 합성된 DEM 과 기존의 waterline 방법과 음향측심법으로 제작된 DEM 과 비교해 본 결과, 합성된 DEM 은 음향측심 자료에 의해 정밀도가 많이 향상되었으며 waterline 방법에 의해 지역적 특성이 잘 표현되었다. 따라서 개발된 방법은 음향측심 방법에 의해 만들어졌던 기존 해도의 정밀도를 업그레이드 하는데 활용될 수 있을 것으로 기대된다.