The porpoise had become trapped in a flooded rice paddy in Japan's Miyagi prefecture after the March 11 tsunami and was struggling and growing weak in the shallow water.
"A man passing by said he had found the [porpoise] in the rice paddy and that we had to do something to save it," Ryo Taira, a pet-store owner who has been instrumental in rescuing animals affected by the earthquake, told Reuters.
Taira and other volunteers rushed to save the animal, fashioning a stretcher of sorts from objects -- including a futon mattress -- strewn in the area. But they were unable to catch the porpoise with a net.
Eventually, Taira managed to catch the porpoise in his arms -- a feat he speculated to Reuters was possible only because the creature was so exhausted from its ordeal.
According to Agence France-Presse, damage to nearby aquariums caused by the disaster left the rescuers with no choice but to release the porpoise into the ocean. They wrapped it in wet towels for the trip back to open water and set it free.
Taira told Reuters that the porpoise's condition seemed to improve when it was returned to the ocean. "I don't know if it will live, but it's certainly a lot better than dying in a rice paddy," Reuters quoted the rescuer as telling Japan's Asahi Shumbun news organization.