• Journal of Environmental Impact Assessment
• /
• v.14 no.3
• /
• pp.127-134
• /
• 2005

Recently, aquaculture farm sites have been increased with demand of the expensive fish species and sea food like as seaweed, laver and oyster. Therefore coastal water quality have been deteriorated by organic contamination from marine aquaculture farm sites. For protecting of coastal environment, we need to control the location of aquaculture sites. The purpose of this study is to detect the laver aquaculture sites using multispectral remotely sensed data with autodetection algorithm. In order to detect the aquaculture sites, density slice and contour and vegetation index methods were applied with SPOT and IKONOS data of Shinan area. The marine aquaculture farm sites were extracted by density slice and contour methods with one band digital number(DN) carrying 65% accuracy. However, vegetation index algorithm carried out 75% accuracy using near-infra red and red bands. Extraction of the laver aquaculture site using remotely sensed data will provide the efficient digital map for coastal water management strategies and red tide GIS management system.

• Bulletin of the Korean Space Science Society
• /
• 2007.04a
• /
• pp.61-61
• /
• 2007

• Fisheries and Aquatic Sciences
• /
• v.11 no.4
• /
• pp.209-211
• /
• 2008

Heterotrophic dinoflagellate Pfiesteria piscicida (Dinophyceae) has been claimed to produce potent ichthyotoxins that cause disorientation and eventually death of fish and other marine animals. A real-time PCR probe targeting for SSU rRNA gene was used for detection of P. piscicida in Chinhae Bay, Korea. PCR inhibitors were successfully removed by dilution of template DNA. Positive detections were shown from surface water samples indicating the presence of P. piscicida in Chinhae Bay.

• ALGAE
• /
• v.31 no.4
• /
• pp.373-378
• /
• 2016

Cochlodinium polykrikoides is a red-tide forming dinoflagellate that causes significant worldwide impacts on aquaculture industries and the marine ecosystem. There have been extensive studies on managing and preventing C. polykrikoides blooms, but it has been difficult to identify an effective method to control the bloom development. There is also limited genome information on the molecular mechanisms involved in its various ecophysiology and metabolism processes. Thus, comprehensive genome information is required to better understand harmful algal blooms caused by C. polykrikoides. We estimated the C. polykrikoides genome size using flow cytometry, with detection of the fluorescence of DNA stained with propidium iodide (PI). The nuclear genome size of C. polykrikoides was 100.97 Gb, as calculated by comparing its mean fluorescence intensity (MFI) to the MFI of Mus musculus, which is 2.8 Gb. The exceptionally large genome size of C. polykrikoides might indicate its complex physiological and metabolic characteristics. Our optimized protocol for estimating the nuclear genome size of a dinoflagellate using flow cytometry with PI can be applied in studies of other marine organisms.

• Journal of Information Technology Services
• /
• v.11 no.sup
• /
• pp.177-189
• /
• 2012

We developed the ocean disaster detection system(OD2S) which copes with the occurrences of ocean disasters (e. g. the red and green tide, the oil spill, the typhoon, and the sea ice) by converging and integrating the ocean color remote sensing using the satellite and the information technology exploiting the mass data processing and the pattern recognitions. This system which is based on the cosine similarity detects the ocean disasters in real time. The existing ocean color sensors which are operated in the polar orbit platforms cannot conduct the real time observation of ocean environments because they support the low temporal resolutions of one observation a day. However, geostationary ocean color imager(GOCI), the first geostationary ocean color sensor in the world, produces the ocean color images(e. g. the chlorophyll, the colored dissolved organic matter(CDOM), and the total suspended solid(TSS)), with high temporal resolutions of hourly intervals up to eight observations a day. The evaluation demonstrated that the OD2S can detect the excessive concentration of chlorophyll, CDOM, and TSS. Based on these results, it is expected that OD2S detects the ocean disasters in real time.

• Fisheries and Aquatic Sciences
• /
• v.11 no.4
• /
• pp.205-208
• /
• 2008

The mixotrophic dinoflagellate Cochlodinium polykrikoides was reported to be linked to major fish kills in Korea and Japan since the 1990s. Rapid and sensitive detection of microalgae has been problematic because morphological identification of dinoflagellates requires light microscopic and scanning electron microscopic observations that are time consuming and laborious compared to real-time PCR. To address this issue, a real-time PCR probe targeting the ITS2 rRNA gene was used for rapid detection and quantification of C. polykrikoides. PCR inhibitors in water column samples were removed by dilution of template DNA for elimination of false-negative reactions. A strong association between cell quantification using real-time PCR and microscopic counts suggests that the real-time PCR assay is an alternative method for cell estimation of C. polykrikoides in environment samples.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.6
• /
• pp.674-680
• /
• 2020

Quantitative real-time polymerase chain reaction (qPCR) was applied for the early detection of red tides in the coastal areas of South Gyeongsang in 2019. Cochlodinium polykrikoides (Dinophyceae) was detected at very low cell densities (0.0015~0.0058 cells mL^-1) in early June, but its cell density increased by up to 0.163 cells mL^-1 in mid-August. Higher cell densities were detected mainly in Namhaedo using both qPCR and microscopy (maximum 24 cells mL^-1) in late-August. Accordingly, a red tide alert was issued on September 2 (maximum 200 cells mL^-1) on this island. C. polykrikoides cell density in Namhaedo peaked on September 11 (12,000 cells mL^-1). Our results indicate that C. polykrikoides was detected at very low cell density in Namhaedo prior to bloom, which occurred in the same area. Therefore, qPCR is a useful tool to detect even at very low cell densities of C. polykrikoides for early warning of blooms.

• Proceedings of the KSRS Conference
• /
• 2008.03a
• /
• pp.170-175
• /
• 2008

본 연구는 MODIS에서 제공하는 클로로필 정보를 기반으로 하여 2단계 필터링을 통해 우리나라 동해, 남해 연안에 대규모로 발생했던 Cochlodinium polykrikoides 적조를 탐지하는 알고리즘을 제시한다. 일반적인 적조 탐지 연구들은 클로로필과 적조 발생의 상관성을 이용하여 클로로필의 농도가 높은 해역을 적조 발생 해역으로 탐지한다. 하지만 이 방법의 문제점은 적조가 발생하지 않은 해역을 적조 발생 해역으로 탐지함으로써 commission error를 발생시킨다는 것이다. 따라서 본 연구에서는 이러한 문제점을 극복하기 위해 MODIS에서 제공하는 클로로필 정보를 바탕으로 적조 발생 해역을 추출하고, 2단계 필터링 과정을 적용함으로써 진해, 여수, 남해도 부근 해역에서 발생한 commission error를 제거할 수 있었으며, 그 결과를 국립수산과학원의 적조속보자료와 함께 시각적 평가하여 본 연구에서 제안한 알고리즘의 효용성을 검증하였다. 향후 정량적인 평가를 위해 F-measure, JC(Jaccard coefficient), YC(Yule coefficient), 전체정확도를 탐지정확도 측정치로써 도입하여 정확도평가를 수행할 예정이다.

• ALGAE
• /
• v.24 no.2
• /
• pp.105-110
• /
• 2009

The rDNAs of figh-killing dinoflagellates Cochlodinium polykrikoides and Karlodinium veneficum were detected from the East China Sea by species-specific real-time PCR probes. Sequence analysesusing the partial ITS sequences from the real-time PCR products showed identical sequences with C. Polykrikoides and K. veneficum, respectively and low expectation values (E-value) of less than 1e-5 suggesting the presence of these organisms in the East Ching Sea shelf water that flows into the Tsushima Strait and the Yellow Sea.

• Proceedings of the KSRS Conference
• /
• v.1
• /
• pp.441-444
• /
• 2006

The MERIS MCI (Maximum Chlorophyll Index), measuring the radiance peak at 709 nm in water-leaving radiance, indicates the presence of a high surface concentration of chlorophyll ${\underline{a}}$ against a scattering background. The index is high in 'red tide' conditions (intense, visible, surface, plankton blooms), and is also raised when aquatic vegetation is present. A bloom search based on MCI has resulted in detection of a variety of events in Canadian, Antarctic and other waters round the world, as well as detection of extensive areas of pelagic vegetation (Sargassum spp.), previously unreported in the scientific literature. Since June 1 2006, global MCI composite images, at a spatial resolution of 5 km, are being produced daily from all MERIS (daylight) passes of Reduced Resolution (RR) data. The global composites significantly increase the area now being searched for events, though the reduced spatial resolution may cause smaller events to be missed. This paper describes the composites and gives examples of plankton bloom events that they have detected. It also shows how the composites show the effect of the South Atlantic Anomaly, where cosmic rays affect the MERIS instrument.