Tiny ocean plants, or phytoplankton, were long thought to be passive drifters in the sea — unable to defy even the weakest currents, or travel by their own volition. In recent decades, research has shown that many species of these unicellular microorganisms can swim, and do so to optimize light exposure, avoid predators or move closer to others of their kind. Now Professor Roman Stocker, William Durham Ph.D. ’12 and grad student Michael Barry have shown that the motility of phytoplankton also helps them determine their fate in ocean turbulence. Rather than acting to distribute them evenly — as physics would demand of small particles mixed into a fluid — the individual vortices that make up ocean turbulence are like social mixers for phytoplankton, bringing similar cells into close proximity, potentially enhancing sexual reproduction and other ecologically desirable activities. Read a news release.