Effects of Light Quantity and Quality on the Growth of the Harmful Dinoflagellate, Cochlodinium polykrikoides Margalef (Dinophyceae)
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Seok Jin Oh1, Yang Ho Yoon2*, Dae-Il Kim3, Yohei Shimasaki4, Yuji Oshima4 and Tsuneo Honjo4
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1Mie Industrial Enterprise Support Center (MIESC), Sakaecho, Tsu 514-0004, Japan 2Faculty of Marine Technology, Chonnam National University, Yeosu 550-749, Korea 3Marine Pollution Control Bureau, Korea Coast Guard, Incheon 406-741, Korea 4Laboratory of Marine Environmental Science, Faculty of Aquaculture, Kyushu University, Fukuoka 812-8581, Japan
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ABSTRACT |
The effects of light quality and irradiance on the growth of Cochlodinium polykrikoides were investigated in the laboratory. At 25°C and 30 psu the irradiance-growth curve was described as μ = 0.34 (I-9.76)/(I+12.5), (r=0.98). This suggests half-saturation photon flux density (PFD) (Ks) of 32.0 μmol photons m?2 s?1, and a compensation PFD (Ic) of 9.76 μmol photons m?2 s?1. Because the Ic equates to a depth of ca. 15.4 m, these responses suggest that irradiance at the depth around and below the thermocline in Yeosuhae Bay would provide favorable conditions for C. polykrikoides. Photoinhibition did not occur at 300 μmol photons m?2 s?1, which was the maximum irradiance used in this study. Blue (450 nm), yellow (590 nm) and red (650 nm) light had different effects on the growth of C. polykrikoides: it grew well under blue light, but not under yellow light. This implies that C. polykrikoides is more likely to cause an outbreak of red tide in the open sea where blue-green wavelengths predominate, rather than in enclosed water bodies where suspended particles absorb most of the blue wavelengths, and yellow-orange wavelengths predominate.
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Key words:
Cochlodinium polykrikoides, growth, harmful dinoflagellate, irradiance, light quality |
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