Primary productivity in the marine environment is accomplished mainly by plankton. In this interview and marine footage based episode, marine experts discuss the role played by the different types of Plankton and how they create energy for millions of species. We examine how they make up an essential part of the food supply for every species living in the oceans and without them life on Earth would not exist. There is additional discussion on the types of plankton, their distribution, and productivity are presented along with methods for measuring primary productivity and factors that limit productivity. This program is an excellent resource for students of biology and marine biology.