Plankton active orientational response to vorticity can enable surfing

Plankton have the potential to enhance their transport by taking advantage of ocean turbulence. However, plankton are limited by what they can sense and respond to in any flow. Acceleration, both translational and rotational, can likely be sensed by molluscan larvae which have statocysts. This would enable the larvae to respond to vorticity. In this talk, we present experimental evidence that demonstrate plankton with an active behavioral response to the local vorticity in a turbulent flow. We study a bottom-heavy, larval planktonic snail in a jet-stirred turbulence tank. Their observed behaviors contrast with passively-rotating gyrotactic plankton, as it indicates they can actively stabilize their upright posture in turbulence. Finally, we compare our observations to a model of "surfing", a theorized navigational strategy that would enable plankton to preferentially sample upwelling areas in a turbulent flow. We find some agreement between the observations and simulated surfers, suggesting that real plankton may indeed be able to "surf" turbulence.