Ocean is for the flora it shelters a particularly variable environment from the viewpoint of its optical properties: coastal waters are green, whereas offshore waters are more bluish... Additionally, all wavelengths of solar spectrum do not penetrate equally at depth: ultraviolet radiations and red light are absorbed already in the first few meters, then yellow, purple and green disappear at their turn, leaving only blue photons at the bottom of the lit layer. What are the consequences for the phytoplankton which draws its energy from sun?
