Plankton are the unsung heroes of planet Earth. Passive drifters through the world’s seas, oceans, and freshwater environments, most are invisible or very small, but some are longer than a whale. They are the global ocean’s foundation food, supporting almost all oceanic life, and they are also vitally important for land-based plants, animals, and other organisms. Plankton provides an incomparable look at these remarkable creatures, opening a window on the elegance and grace of microscopic marine life. This engaging book reveals the amazing diversity of plankton, how they belong to a wide range of living groups, and how their ecology, lifestyles, and adaptations have evolved to suit an enormous range of conditions. It looks at plankton life cycles, the different ways plankton feed and grow, and the vast range of strategies they use for reproduction. It tracks where, how, and why plankton drift through the water; shares perspectives on migrations and population explosions or 'blooms' and why they happen; and discusses the life-sustaining role of plankton in numerous intertwined food webs throughout the world. Beautifully illustrated, Plankton sheds critical light on how global warming, pollution, diminishing resources, and overexploitation will adversely impact planktonic life, and how these effects will reverberate to every corner of our planet.