Determination of effective parameters on growth and bloom forming of Cochlodinium polykrikoides

Authors

Abstract

Harmful algal blooms resulting in red discoloration of coastal waters in the Persian Gulf,
Iran were first observed in January 2007. The species responsible for the bloom, which was
identified as Cochlodinium polykrikoides, coincided with massive aquatic organisms’
mortalities in the Persian Gulf. In order to provide optimum growth and bloom forming, C.
polykrikoides cells were sampled during the bloom conditions in the coastal waters of Persian
Gulf. After adaptation in filtered seawater, they isolated by positive phototropism
characteristic of this species to light. They were grown in modified media culture at different
salinity (30, 32 and 35ppt), temperature (20, 23, 26 and 28ºC) and intensity (35, 70 and 90
μmol m-2s-1). The results of the present study clearly showed that the highest alga biomass and
growth rate was obtained following culture under the 32ppt salinity, 26°C temperature, and
under a 12h light:12h dark photoperiod regime at a light intensity of 90μmol m-2s-1 provided
by cool white fluorescent tubes. Maximum cell density and growth rate of C. polykrikoides in
a 60 liter tank for 20 days reached to 32×106 cell L−1 and 0.28 day-1, respectively. However,
the mean obtained cell density of C. polykrikoides in temperature regimes 20, 23, 26 and 28ºC
(under salinity of 32ppt, and 90μmol m-2s-1 irradiance) were 2730, 9360, 28240 and 18080
cell ml-1, respectively. A two-way ANOVA indicated significant effects of temperature on the
growth rate of C. polykrikoides followed by salinity, and then the interaction between
temperature and salinity.

Keywords

Iranian Scientific Fisheries Journal
Volume 21, Issue 2 - Serial Number 79
March and April 2013
Pages 31-40

Files

Share

How to cite

Statistics