The eggs were taken to the Aquamarine Fukashima aquarium because of fears the nesting sites would be covered at high tide, the Asahi Shimbun reported. A beach walker found the eggs in August 2011 on Shin-Maiko Beach, and scientists gathered 127 of them.
The turtles were released on the same beach.
Loggerheads are an endangered species although they are one of the most widely distributed sea turtles, found in the Atlantic, Pacific and Indian oceans. They are protected by international agreements.
The Great East Japan earthquake and tsunami in March 2011 devastated many coastal areas, killing thousands of people.