From zooplankton to phytoplankton, these small-scale superheroes are the foundation of the ocean's food chain, keep our climate in check, generate up to fifty percent of the oxygen produced on the planet each year-and much more. Stunning microscopic photos and primary source research provide a seldom seen look at these dynamic drifters. "Science interpreter," Mary Cerullo, dives into the wet world of plankton, and takes a deep look at the good and the bad, the tiny and even tinier. Readers will discover even the smallest actors can make a big difference. Glossary and informative sidebars included.