Movement
As phytoplankton is a plant organism it cant move by itself. It travels far distances by being pulled onlong with the oceans current and usually gets dragged into large groups by the ocean current pushing together. These large groups of Phytoplankton attract many different types Oceanic life and many of these creatures only come for the Species that come for the mass amount of Phytoplankton like Leopard Seals they only come for the fish, Squids and Penguins that come to feed on the Phytoplankton.
Mass Phytoplankton Group