Right after the Great East Japan Earthquake struck in March 2011, Junichi Jingu, manager of exhibits at Marinepia Matsushima Aquarium, feared that he would never see its rare Commerson's dolphins again.

"The shaking was so strong that I thought the floors would collapse," Jingu, 59, recalled.

The aquarium in Miyagi Prefecture's famed coastal town managed to evacuate its crowds to higher ground before the huge tsunami struck. But when Jingu returned several hours later, a scene of devastation greeted him.