Temperature and salinity effect on growth and chemical composition of Gyrodinium aureolum Hulburt in culture

A factorial experiment shows highly significant effects of temperature (12 5–22.5°C) and salinity (17.8–34 S‰) on the growth rate of Gyrodinium aureolum , with a significant temperature-salinity interaction. The maximum growth rate of G aureolum is measured to 0.61 div. day −1 at 20°C and 22.3 S‰. Gyrodinium aureolum does not grow at temperatures :≤10 °C or ≥25°C and at salinities ≤12 S‰. The cellular content of carbon (C) and nitrogen (N) and the elemental ratios N/C, P/C and N/P are significantly affected by the temperature The cellular content of phosphorus (P) and the elemental ratios P/C and N/P vary significantly with salinity Significant temperature-salinity interactions are found for the cellular content of carbon, nitrogen and phosphorus. Variations in the N/P ratio indicate that G.aureolum has a large storage capacity for phosphorus It is suggested that temperature is one important limiting factor in the initiation of blooms of G.aureolum in north European waters.