Methods of growing and harvesting multiple phytoplankton species aredisclosed. The method comprises: (1) transporting a first volume ofphytoplanktonseawater (FVPS) containing multiple species of naturally-occurringphytoplankton(MSNOP) directly from a source of seawater into at least one tank； (2)depriving theFVPS of light to form a first volume of light-deprived phytoplankton seawater(FVLDPS)； (3) adding nutrients to the FVLDPS to proliferate the MSNOP to apredetermined density faster than the growth cycle of non-light deprivedphytoplankton； (4) withdrawing a volume of the light-deprived phytoplanktonseawaterfrom the tank and adding a second volume of seawater containing MSNOP directlyfrom the source of seawater to the tank to initiate the growth ofphytoplankton, thesecond volume of seawater substantially equivalent to the volume of light-deprivedphytoplankton seawater withdrawn from the tank； (5) separating the MSNOP fromthewithdrawn light-deprived phytoplankton seawater to form a phytoplanktonconcentrate；and (6) collecting the phytoplankton concentrate for use in nutraceuticalapplications.
