Which zone has the most plankton Profundal Littoral or Limnetic?

The Limnetic zone should have the most plankton, as it is the section with the best suitable conditions for organisms to thrive. The Limnetic zone is wide opened to sunlight, and is also oxygen filled. However the profundal zone has a very limmited supply of oxygen and sunlight, which makes the water cold and harder for organisms, such as plankton to thrive there.