Watch The Dark Side of the Ocean (2015) : Full Movie Online Free Marine biologist and cameraman Rick Rosenthal has been filming in the ocean for decades, but one spectacle has eluded him and other filmmakers, until now. It is a vast “vertical migration” that happens every night, in which billions of animals rise up from the depths. Rosenthal captures the often bizarre and still unchartered life forms that make up the largest animal migration on the planet.