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Moving Heaven and Ocean

August 24, 2017

In 1963, WHOI biologist Dick Backus, shown here watching the return from a precision graphic recorder, used a solar eclipse to solve a puzzling oceanographic mystery. For decades, scientists had known that plankton and other organisms migrate vertically in the ocean every day, but no one knew whether the organisms, collectively forming the largest migration on Earth, timed their movements with the sun or some other clock. Backus and a team on the WHOI research vessel Chain watched as the passage of the eclipse triggered the same behaviors—mass vertical movement and an increase in bioluminescent activity—as sunset and sunrise, indicating that changing light level was the trigger. (Photo courtesy of Woods Hole Oceanographic Institution Archives)