Improving light and CO2 availability to enhance the growth rate of the diatom, Chaetoceros muelleri

Abstract Diatoms (Bacillariophyceae) are an important source of feed for juvenile animals in aquaculture hatcheries. Increasing the yield of feed cultures by optimizing illumination and inorganic carbon supply could significantly reduce operational costs for hatcheries. In this study, the growth dynamics and photosynthetic efficiency of the aquaculture-relevant diatom Chaetoceros muelleri were monitored and modelled under four different light and CO2 conditions. By increasing the availability of both light and CO2, a growth rate of 1.59 ± 0.12 (day−1) was achieved for C. muelleri, an increase of approximately 89% compared to 0.84 ± 0.08 (day−1) which was recorded in cultures under light limitation with no CO2 addition. The real-time monitoring and modelling of growth dynamics and photosynthesis rates in different light and CO2 conditions have demonstrated that light availability can be improved by minimizing the path length of light through the culture, and the importance of on-demand CO2 supply. The techniques and results outlined in this study could be used to potentially improve biomass production in hatcheries.