Nannochloropsis algae cells are cultivated with sunlight, mineral salts and CO2 in closed photobioreactors or open raceway ponds. Seawater is used for its cultivation as it is a marine strain. Once the required growth rate is reached, under nitrogen deprived conditions, the algae produces omega-3 fatty acids in the cells. If the cells have accumulated about 60-70% of lipids, the algae are subjected to harvesting.