Passing clouds cause some marine animals to make mini-migrations during the day

Every evening, small fish and microscopic animals called zooplankton journey to the ocean surface, where they feast on microscopic plants under the moonlight before returning to the depths at dawn. With data collected during the EXport Processes in the Ocean from Remote Sensing (EXPORTS) field campaign in 2018 to the Northeastern Pacific Ocean, scientists have now shown that some zooplankton living in the twilight zone of the ocean at depths of greater than 300 meters swim up and down also in response to shifts in light due to cloud cover.