The effect of temperature on carbon, nitrogen elements, and chlorophyll-a content in harmful algal blooms and their role in marine carbon and nitrogen cycles.

This study investigates the impact of temperature on the carbon, nitrogen elements, and chlorophyll-a content in harmful algal blooms, revealing their potential contribution to blue carbon ecosystems. By culturing 15 species of dinoflagellate at various temperatures, we measured their carbon, nitrogen, and chlorophyll-a content. The results indicated that temperature significantly influences the growth rate, C/N ratio, and chlorophyll-a content of these dinoflagellate. Within a moderate temperature range of 14 °C-26 °C, dinoflagellate exhibited optimal growth and carbon fixation capacity, whereas both high (30 °C) and low (6 °C) temperatures inhibited growth. Certain species, such as Akashiwo sanguinea, displayed enhanced carbon fixation capacity at higher temperatures, with a marked increase in the C/N ratio, suggesting metabolic adjustments to environmental changes. This study offers new insights into the ecological role of dinoflagellate in the context of global warming.