Cultivation of aquaculture feed Isochrysis zhangjiangensis in low-cost wave driven floating photobioreactor without aeration device.

This study aimed to use floating photobioreactor (PBR) to produce microalgae biomass for aquaculture applications, and this was tested with cultivation of Isochrysis zhangjiangensis. The highest cell density of 16.1 ± 0.61 × 10 cell L was obtained in an outdoor culture with a depth of 5.0 cm in 1.0 m floating PBR, but deeper culture resulted in higher biomass productivity. Large-scale cultivation at size of 10 m (1000 L) produced the highest cell density of 17.8 × 10 cell L and highest biomass productivity of 0.115 g L d, which was at the same level as that for flat-panel PBR (100 L). This developed technique provides an innovative approach to produce microalgae on site for use as fresh aquaculture feed, as well as fresh cells for use as seed inoculums for large-area aquaculture water bodies. This approach provides not only a low-cost microalgae production system but also better integration between microalgae production and aquaculture.