The third activity will explore the (i) incorporation of sulfated polysaccharides in microalgae concentrates (Immuno PhytoBloom), as well as the (ii) development of a food additive with immunostimulatory activity for aquaculture (Immuno4Fish). In this activity, a Challenge will be carried out in sea bream for (iii) validation of the immunostimulatory activity of Immuno4Fish.