• Fisheries and Aquatic Sciences
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• v.7 no.3
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• pp.148-162
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• 2004

The monitoring activities at the National Fisheries Research and Development Institute (NFRDI) in Korea have been extended to include all the coastal waters of Korea after the outbreak of Cochlodinium polykrikoides blooms in 1995. We used several alternative methods including climatological analysis, spectral and optical methods which may offer potential detection of the major species of red tide in Korean waters. In the climatological analysis, NOAA, SeaWiFS, OCM satellite data was chosen using the known C. polykrikoides red tide bloom data and the area was mapped by helicopter reconnaissance and ground observation. The relationship between the distribution of sea surface temperature to C. polykrikoides bloom areas was studied. The anomalies of SeaWiFS chlorophyll a imageries against the imageries of non-occurring red tide for August, 2001 showed where the C. polykrikoides occurred. The anomalies of chlorophyll a concentrations from the satellite data during red tide outbreaks showed a similar distribution of C. polykrikoides in the red tide in August, 2001. The distribution between differences in sea surface temperatures during the day and at night also showed a possibility for red tide detection. We used a corrected vegetation index (CVI) to detect floating vegetation and submerged vegetation containing algal blooms. The results of from the optical absorption of C. polykrikoides in the ultraviolet band (340 nm) showed that if we use the optical characteristics from each red tide, we will be able to establish the feasibility of red tide detection.

• Ocean and Polar Research
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• v.35 no.1
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• pp.15-26
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• 2013

The toxic, Harmful Algal Blooms (HABs) caused by the Cochlodinium polykrikoides have a serious impact on the coastal waters of Korea. In this study, the acoustic detection system was developed for rapid HABs detection, based on the acoustic backscattering properties of the C. polykrikoides. The developed system was mainly composed of a pulser-receiver board, a signal processor board, a control board, a network board, a power board, ultrasonic sensors (3.5 and 5.0 MHz), an environmental sensor, GPS, and a land-based control unit. To evaluate the performance of the system, a trail was done at a laboratory, and two in situ trials were conducted: (1) when there was no red tide, and (2) when there was red tide. In the laboratory evaluation, the system performed well in accordance with the number of C. polykrikoides in the received level. Second, under the condition when there was no red tide in the field, there was a good correlation between the acoustic data and sampling data. Finally, under the condition when there was red tide in the field, the system successfully worked at various densities in accordance with the number of C. polykrikoides, and the results corresponded with the sampling data and monitoring result of NFRDI (National Fisheries Research & Development Institute). From the laboratory and field evaluations, the developed acoustic detection system for early detecting HABs has demonstrated that it could be a significant system to monitor the occurrence of HABs in coastal regions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11B
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• pp.1339-1345
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• 2011

Red tide is a natural phenomenon that change sea color by harmful algal blooms. There have been many studies on red tide due to increasing of red tide damage. However, to automatically classify the red tide algae is not enough. Recognition of red tide algae is difficult because they do not have matching center features for recognizing algae image object. Previously studies are used a few type of red tide algae for classification. In this paper, we proposed the red tide algae recognition method using PCA and roundness of image objects.

• Proceedings of the KSRS Conference
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• v.1
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• pp.360-363
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• 2006

The red tide related with Cochlodinium Polykrikoides bloom has been frequently occurred around the South Sea of Korea and caused the economic loss in the coastal breeding grounds. The outbreak scale was usually change by physical, biological and environmental condition at each years. Relatively large-scale red tide occurred in 1995, 1997, 1999, 2001, 2002 and 2003 through spatial scale, duration and maximum density. Compared the scale of red tide with physical condition around the South Sea, the lower coastal temperature on August around the South Sea corresponded with the large scale red tide. By serial oceanographic investigations on August in the South Sea and estimated wide area temperature information by satellite, SSTA around the South Sea and wide area was negative when the outbreak of red tide was large scale. From the results of temperature difference between surface and 30m layers, the occurrence of enormous red tide has a tendency when the temperature gradient around the seasonal thermocline was weakened. Larger Kuroshio volume transport in the upstream was also corresponded with the large scale red tide.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.2
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• pp.125-135
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• 2001

The research on Harmful Algal Blooms is generally in progress through field work, such as the naked eye and sampling. It was difficult to forecast exactly the course, from appearance of red tide to disappearance, with the established ways of investigation and analysis. Accordingly it is need to analyze environmental factors in time and space, the appearance of red tide and the path of its migration by more objective and scientific methods. In this study the remote sensing was used to diminish damage from the occurrence of red tide. Such as a temperature change of sea water and a change of tidal currents, the major cause for red tide. The probed data were utilized. The technique for forecast of red tide phenomenon on the south coast was researched by analyzing the cause of red tide, pollutant flowed from landand the possibility of application of the technique was showed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.6
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• pp.405-412
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• 2014

A number of algal bloom models (red-tide models) have been developed and applied to simulate the redtide growth and decline patterns as the interest on the phytoplankton blooms has been continuously increased. The quantitative error analysis of the model is of great importance because the accurate prediction of the red-tide occurrence and transport pattern can be used to setup the effective mitigations and counter-measures on the coastal ecosystem, aquaculture and fisheries damages. The word "red-tide model" is widely used without any clear definitions and references. It makes the comparative evaluation of the ecological models difficult and confusable. It is highly required to do the performance test of the red-tide models based on the suitable classification and appropriate error analysis because model structures are different even though the same/similar words (e.g., red-tide, algal bloom, phytoplankton growth, ecological or ecosystem models) are used. Thus, the references on the model classification are suggested and the advantage and disadvantage of the models are also suggested. The processes and methods on the performance test (quantitative error analysis) are recommend to the practical use of the red-tide model in the coastal seas. It is suggested in each stage of the modeling procedures, such as verification, calibration, validation, and application steps. These suggested references and methods can be attributed to the effective/efficient marine policy decision and the coastal ecosystem management plan setup considering the red-tide and/or ecological models uncertainty.

• Fisheries and Aquatic Sciences
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• v.6 no.3
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• pp.160-163
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• 2003

Mortality of several species of fish and shellfish exposed to Harmful Algal Blooms (HABs) caused by Cochlodinium polykrikoides, Heterosigam akashiwo, Alexandrium tamarense, Eutreptiella gymnastica, Heterocapsa triquetra and Prorocentrum micans was studied. When fish were exposed to a cell density of 8,000 cells $mL^{-1}$ in C. polykrikoides, $35\%$ of flatfish and darkbanded rockfish died within 48 hrs. However, jacopever rockfish had mortality of higher than $85\%$. Rock bream, filefish and red sea bream showed $100\%$ mortality within 10 hrs with an exposure cell density of 8,000 cells $mL^{-1}$. The rest of HABs except for C. polykrikoides showed that there was no fish and shellfish death throughout the 48 hrs even in the maximum cell density of 100,000 cells $mL^{-1}$ These results imply that C. polykrikoides can have a serious impact on fish mortality and it is regarded as an ichthyotoxic dinoflagellate. The fish death may be attributed to anoxia caused by a combination of the production of reactive oxygen species (ROS) and polysaccharide from C. polykrikoides during blooms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.331-336
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• 2012

Red tide is a temporary natural phenomenon involving harmful algal blooms (HABs) in company with a changing sea color from normal to red or reddish brown, and which has a bad influence on coast environments and sea ecosystems. The HABs have inflicted massive mortality on fin fish and shellfish, damaging the economies of fisheries for almost every year from 1990 in South Korea. There have been many studies on red tide due to increasing damage from red tide on fishing and aquaculture industry. However, internal study of automatic red tide image classification is not enough. Especially, extraction of matching center features for recognizing algae image object is difficult because over 200 species of algae in the world have a different size and features. Previously studies used a few type of red tide algae for image classification. In this paper, we proposed the red tide image recognition method using NMF and revison of rotation angle for enhancing of recognition of red tide algae image.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.4
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• pp.120-140
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• 2013

We investigated the occurrence of red tide, harmful algal blooms(HABs), at the end of 14th century until the beginning of 19th century recorded in the Annals of the Joseon Dynasty, which are the authentic and encyclopedic annual records of the Joseon Dynasty of Korea. In total, 81 cases of HABs are recorded in the annals for which authors draw a table and maps. The number of HABs occurrence at each sea is as follows: 68 times at the South Sea; 50 times at the East Sea; and 23 times at the Yellow Sea. A region hit by red tide most frequently was Gyeongsang-do Province (over 80 times), which borders on both the South Sea and the East Sea. HABs written in the annals follow two distinctive occurrence patterns. The first pattern shows red tide started at Gangwon-do Province in March, spread north to Hamgyeongnam-do Province in April, and moved further north to Hamgyeongbuk-do Province in May and June. On the other hand, the second pattern shows red tide occurred in Gyeongsangnam-do Province in August and then expanded north to Gyeongsangbuk-do Province in September. HABs generally happened from March to September, culminating in August. Paralytic shellfish poisoning incidents involving human deaths were reported in Jinhae, Geoje and Tongyeong, occurring February to June. Fish mortality increased throughout Gyeongsang-do Province from July to September. HABs occurred on an extensive scale from 1394 to 1451 and again from 1654 to 1706. HABs also occurred on a lesser scale from 1493 to 1534 and again from 1588 to 1609. In general, vast HABs occurred in odd years (1399, 1403, 1413 and 1681).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.445-456
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• 2001

In the 1990s, Cochlodinium polykikoides red tide has been annually occurred in the southern coast of Korea and caused the mass damage to the fisheries with a huge amount of economic loss. The present study was done to establish the biological foundation for the elucidation of the mechanism of C. polykikoiaes red tide. The growth response of C. polykikoides to physico-chemical factors such as temperature, salinity, pH, and light intensity were examined using axenic cultures to evaluate the relative importance of these factors on the dynamics of natural populations, It was found that the highest growth conditions were $25^{\circ}C,\;40\%_{\circ}$, pH 7.5, and 7,500 lux, respectively. The tolerable salinity range of growth was relatively wide at an optimum temperature and was reduced to a much narrower range at a sub-optimum temperature. These findings indicate that C. polykikoides is an eurythermal and euryhaline organism. The organism demanded higher light intensity and oceanic pH narrow in its growth. C. polykikoides utilize inorganic nutrients, such as nitrate and ammonium as N, and phosphate as P. The nutritional requirements of C. polykikoides were $40{\mu}M$ for nitrate, $50{\mu}M$ for ammonium, and $5{\mu}M$ for phosphate. The half saturation constant (Ks) for growth was $2.10{\mu}M$ for nitrate, $1.03{\mu}M$ for ammonium, and $0.57{\mu}M$ for phosphate. These values were comparatively smaller than those of other dinoflagellates reported previously. We confirmed that the organism is characterized as an eutrophic species. However, ammonium Ks value is smaller than that of other eutrophic species, This result indicates that C. polykikoides red tide may outbreak in the waters which eutrophication is in progress rather than eutrophicated waters. C. polykikoides preferred ammonium better than nitrate as a nitrogen source when in a growth stage, Therefore, our results indicate that ammonium is more important nutrient on the growth of the organism in comparison with other inorganic nutrients and C. polykikoides red tide is related with the increased ammonium concentration in the coastal waters.