• Journal of Environmental Science International
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• v.11 no.10
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• pp.1069-1074
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• 2002

The growth and heavy metal experiments revealed oppositive interactions between toxic metals(Zn and Cd) and Mn when the coastal diatom T. pseudonana were used. Cd and Zn inhibited the algal growth rate only at low Mn ion concentrations and this effect could be accounted for an inhibition of cellular Mn take by the toxic metals. Mn and Zn inhibited cellular Cd take and this indicated a reciprocal effects among the metals with respect to metal take. Saturation kinetics modeling of the take data was consistent with two metals competing with each other for binding to the Mn take system and with both Cd and Mn being transported into the cell by that system. Mathematical modeling of Mn and Cd take data revealed evidence fur a Cd efflux system.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.185.1-185
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• 1998

No Abstract, See Full Text

• Journal of Environmental Impact Assessment
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• v.20 no.3
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• pp.281-297
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• 2011

The specie composition, stranding crops and the dominant species of phytoplankton were studied in three streams, Namdae-stream, Yeongok-stream and Sacheon-stream from May 2008 to February 2009. The water qualities of the three streams which run into estuary were also examined using phytoplankton indicators. As the result, the phytoplankton appeared 94 taxa in Namdae-stream, 79 taxa in Yeongok-stream and 73 taxa in Sacheon-stream, diatoms appeared the most in phytoplankton. Genus Navicula and Cymbella in diatoms appeared to be over 10 taxa in each stream, N. cryptocephala, N. cryptotenella and N. gregaria, the pollution tolerance taxa, appeared more frequent in the downstream. Due to the separation of each substrate by the rapid water velocity in the upstream, Achnanthes minutissima, a known periphyton, was dominant in upstream site at Namdae and Yeongok-stream. Some construction areas and sites of downstream of Namdae-stream, Yeongok-stream and Sacheon-stream were shown to be polluted because pollution tolerance taxa, such as Cyclotella meneghiniana, Nitzschia palea and Oscillatoria limnetica, were dominant. The total of 20 taxa phytoplankton indicators were found, composed of 16 taxa of Water pollution algae including Oscillatoria limosa, 2 taxa of Clean water algae Meridion circulare and Staurastrum puntulatum, 1 taxa of Toxic algae Microcystis aeruginosa and 1 taxa of Taste and odor algae Fragilaria construens. Water pollution indicators were appeared frequently in polluted sites of biological water quality(DAIpo, TDI) and of sites containing high trophic state index(TSI). Therefore, using the phytoplankton indicators can assess water quality through relation of biological water quality and trophic state index.

• ALGAE
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• v.26 no.3
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• pp.237-241
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• 2011

The toxic dinoflagellate Karlodinium veneficum has been implicated in numerous fish kill events around the world. Since this species commonly co-occurs with other morphologically similar dinoflagellates, field monitoring of this species in natural waters via light microscopy only has been problematic. In this study, we investigated temporal changes in K. veneficum's abundance in the waters of Obido, Tongyeong, using a species-specific real-time polymerase chain reaction (PCR) assay. The field survey, from April to December 2010, revealed K. veneficum occurred at low densities (12 to 425 cells $L^{-1}$) during this time and that cell numbers peaked in June (early summer in Korea), indicating this species generally occurs in the warmer season (mostly at $16.9-22.3^{\circ}C$ and 33.4-34.5‰) in the Obido area.

• ALGAE
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• v.20 no.2
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• pp.157-166
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• 2005

Uptake kinetics of Cd and Zn by leaves and rhizome of the seagrass Zostera marina were examined in controlled laboratory radiotracer experiments. Subsequently, acute toxicity of Cd, Cu and TBT on photosynthetic quantum yield (ΔF/Fm’ of Z. marina were determined, and the differential sensitivities of rapid light curve (RLC) to those harmful substances were also compared. All measurements on photosynthetic activity were determined by chlorophyll a fluorescence method using pulse amplitude modulation (PAM). Metal uptake by Z. marina was saturated with increasing exposure time in leaves and rhizomes. Uptake of Zn by Z. marina was faster than that of Cd. Metal uptake rates in Z. marina decreased with the increase of dissolved metal concentrations and also with the increase of biomass. The adverse effect of TBT on effective quantum yield was stronger than other pollutants. Average acute toxicity on the RLC of the seagrass exposed to TBT and two heavy metals (Cd and Cu) was going to decrease as follows: TBT > Cd > Cu. Our preliminary results in this study suggested that Z. marina potentially can be used as a biomonitor of harmful substances contamination in coastal waters.

• ALGAE
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• v.17 no.3
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• pp.171-185
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• 2002

The standing crop of genus Microcystis, microcystin concentrations and environmental factors were monitored at stations of the lower reaches of the Nakdong River in 1998 and 1999 during the periods of its occurrence. The Microcystis were observed from May to Octorber, and the cell density was highest at Station Seonam up to 250,000 cells${\cdot}ml^{-1}$ forming scum over the water surface. There were signigicant relationships between the standing crop of Microcystis and nitrate nitrogen, total phosphorus concentrations and Ph. Presumably these parameters were important in the succession to Microcystis dominated phytoplankton community in the summer period in the river. However, Ammonium nitrogen, phosphate phosphorus concentrations and N/P ratio were not critical factors. The Microcystis bloom was notable above $25^{\circ}C$ of surface water temperature. Microcystins were detected from May to November in the algal materials from the river. The 84.2% of algal materials with Microcystis exhibited the microcystin with the maximum of 1711.8 ${\mu}g{\cdot}g^{-1}$ dw. The microcystin concentrations in the algal materials were significantly related to the stading crop of Microcystis, which was the primary determinant factor in the toxin levle of algal materials. The concentrations were also significantly related to pH of the water column in the positive pattern.

• ALGAE
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• v.21 no.4
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• pp.433-443
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• 2006

This study was performed to understand the morphological and ecological characteristics of Peridinium bipes var. occultatum Lindem., which is the organism responsible for freshwater red tides in Sangsa dam and Miryang dam reservoirs. The samples were collected from April to July 2004 when the freshwater red tides occurred. In the study, we were able to differentiate P. bipes var. occultatum from P. bipes, a closely related species, by its smaller antapical horn size. In Miryang dam reservoir the red tide occurred only within the area of the upstream, but it was well developed in all of the water area in Sangsa dam reservoir. In 2004 average LTSI (Lake Trophic Status Index; Yang and Dickman, 1993) of Miryang dam reservoir was 3.53 of mesotrophic state and Sangsa dam reservoir was 8.59 of eutrophic state. It was determined, through culture experiments under various conditions that vitamins, trace elements, phosphorus and nitrogen were important contributing factors to the growth of P. bipes var. occultatum. A rapid toxic effect of P. bipes var. occultatum on aquatic organisms such of Daphnia magna and Oryzias latipes was not identified in this study.

• ALGAE
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• v.36 no.2
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• pp.91-109
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• 2021

The occurrence of benthic dinoflagellates, many of which are known to be toxic, is a critical concern for scientists, government officers, and people in the aquaculture, dining, and tourism industries. The interest in these dinoflagellates in countries with temperate climate is increasing because tropical or subtropical species introduced into temperate waters by currents are able to survive the winter season in the new environment owing to global warming. Recently, several species from the benthic dinoflagellate genera Amphidinium, Coolia, Ostreopsis, Gambierdiscus, and Prorocentrum have been reported in the waters of the South and East Sea of Korea. The advent of the benthic dinoflagellates in Korean waters is especially important because raw or slightly cooked seaweeds, which may harbor these benthic dinoflagellates, as well as raw fish, which can be potentially intoxicated by phytotoxins produced by some of these benthic dinoflagellates, are part of the daily Korean diet. The recent increase in temperature of Korean coastal waters has allowed for the expansion of benthic dinoflagellate species into these regions. In the present study, we reviewed the species, distribution, and toxicity of the benthic dinoflagellates that have been reported in Korean waters. We also provided an insight into the ecological and socio-economic importance of the occurrence of benthic dinoflagellates in Korean waters.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.778-784
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• 2017

We investigated the possibility of a bio-monitoring system for predicting toxic dinoflagellates (Genus Alexandrium) by the measuring shell valve movements(SVMs) of Pacific oyster, Crassostrea gigas (Mollusca: Bivalvia) using the Hall element sensor. We then described the SVMs of Pacific oyster exposed to the toxic algae under laboratory conditions. Pacific oyster used for experiment were fed Isochrysis galbana until they stabilized and kept under hunger conditions for three days to prevent the influence of food before the experiment. Pacific oyster were exposed to the toxic dinoflagellate, A. fundyense, and the potentially toxic dinoflagellate, A. affine. When Pacific oyster were exposed to A. fundyense, SVMs increased over 10 times/hr at low cell densities of 20 cells/mL. SVMs increased again at $14.1{\pm}5.7times/hr$ at 500 cells/mL, and $27.9{\pm}11.1times/hr$ at the high cell density of 5,000 cells/mL. However, in the presence of A. affine, SVMs increased at $6.7{\pm}3.9times/hr$ until 300 cells/mL, while they increased greatly to $15.3{\pm}10.8times/hr$ at 1,000 cells/mL. The SVMs of Pacific oyster indicated differences depending on species for toxic dinoflagellates. Therefore, the SVMs of Pacific oyster could be useful for A. fundyense, but would bedifficult to apply for A. affine.

• ALGAE
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• v.19 no.1
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• pp.7-14
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• 2004

Blue-Min was initially developed as an adsorbent for harmful gas removal and recently improved to apply to livestock, agriculture and aquaculture as an assistant feed. In the Blue-Min treatment, growth of harmful algae (Cochlodinium polykrikoides and the others causing the red-tide in the ocean) were inhibited below 10% in comparison with control and coagulation removal of harmful alge with Blue-Min treatment was more efficient than that of yellow loess treatment. It would be expected that the Ble-Min can be useful for the extirpator against the red-tide organisms and restrain the toxic algal growth around the fish aquaculture using the assistant feed. Recently, its utility has become to be diverse as it was revealed that aquaculture productivity increase by its application and, in addition, that it improve the water quality or sediment conditions in the aquaculture of Chinese White Shrimp. When Blue-Min was treated with the proper dose, the growth inhibition of Microcystis aeruginosa and lsochrysis galbana, which are typical red-tide organisms in freshwaters and food organisms in aquaculture, respectively, were less than that of marine red-tide organisms, while their growth slightly increased with low concentration treatiment. In addition, polyunsaturated fatty acids (PUFA) content of I. galbana slightly increase with the Blue-Min treatment. Through our research, the Blue-Min has diverse and comples function against various biological organisms and is proved as a biological activator or depressor.