Why are Plankton so important for Ocean Habitats?

Is this correct if not can u correct me

What can be done to make a solid solute dissolve faster in a liquid solvent?

What do electromagnetic waves carry? how are they produced through which media can they move? where do they transfer energy? what do they not transfer? what do mechanical waves carry? how are they produced? through which media can they move? where do they transfer energy? what do they not transfer?