These mostly microscopic organisms—plant-like phytoplankton and tiny animals known as zooplankton—form the base of most ocean food webs. In spite of their importance, plankton communities in the ocean are poorly understood—in part because the ocean is vast, and plankton communities vary widely by location and over time. Such a vast area would be impossible to sample comprehensively with conventional net tows, so Sosik is using a specialized underwater camera system to image plankton in situ, under the water. The findings are certain to revolutionize our understanding of plankton community dynamics, with implications for ocean food webs, fisheries, and global climate. About the Simons FoundationThe Simons Foundation’s mission is to advance the frontiers of research in mathematics and the basic sciences.