What is in the waves....

Hi Everyone On Sunday night i went for a walk to pond cove and the waves were coming in green! All over the beach was a green color so i scooped some up and put it in a bag with some sea water and then took it into my oceans class the next day to look at it under a microscope. Will post what it was when i finally figure it out myself. There is a few clues....but it needs more investigation. Will let you know when i find out or anyone who might like to take a guess can post a comment. Don't you love nature, Enjoy