Publication Date:
2021-05-19
Description:
Although the most alga blooms usually provide positive impacts on marine ecosystems, but blooming of certain species of algae may also have negative impacts which evidence suggests that over the past few decades the frequency and duration of Harmful Algal Blooms (HABs) have been increasing both nationally and worldwide. Harmful algal blooms of Cochlodinium polykrikoides in the Persian Gulf and Oman Sea were first observed in 2008. In order to provide optimum growth and bloom forming, C. polykrikoides cells were sampled during the bloom conditions in the coastal waters of Bandar Abbass, Qeshm and Hourmoz Islands from March 2012 to June 2015. After sampling, the samples transferred to Persian Gulf and Oman Sea Ecological Research Institute phytoplankton Lab and adapted to filtered seawater. In Phycolab, they isolated and purified by positive phototropism characteristic of species to light. They were grown in modified media culture at different salinities (30, 32 and 35ppt), temperatures (20, 23, 26 and 28ºC) and intensities (35, 70 and 90 µmol m-2s-1). During this study 3 Dinoflagellates species were identified in Hormozgan Coastal waters. The first species was Noctiluca scintillans. This species was alive in F/4 media culture and under the 32ppt salinity, 25°C temperature, and an 11h light: 13h dark photoperiod regime only for 4 months. The second species was Protoperidinium quinquecorne and produced temporal blooms that could not be isolated under usual and modified media cultures. The last Dinoflagellates species that caused spreading blooms in Hormozgan Coastal waters and could be possible to isolate was Cochlodinium polykrikoides. The results clearly showed that the best media culture for growth of this species is A2 and the highest alga biomass was obtained following culture under the 32ppt salinity, 26°C temperature, and under an 11h light: 13h dark photoperiod regime at a light intensity of 90 µmol m-2s-1 provided by cool white fluorescent tubes. Maximum cell density of C. polykrikoides in a 5 liter Erlenmeyer for 12 days reached to 1.6 × 106 cell L−1 with 2-12 and occasionally to 16 cells chain. Based on the results from the present study, providing suitable media culture and physical condition, bloom forming of C. polykrikoides start from day 8 and will be continued until day 24.
Description:
Iranian Fisheries Science Research Institute
Description:
Published
Keywords:
Harmful algal bloom
;
Isolation
;
Dinoflagellates
;
Growth
;
Cochlodinium polykrikoides
Repository Name:
AquaDocs
Type:
Report
,
Refereed
Format:
50pp.
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