Don't believe it, but the photos are fascinating. At the end of World War II a lot of military hardware was dumped along the coastlines of Australia. It was supposed to slow erosion. Studies in the 80's showed that these miscellaneous bits of concrete and metal just increased turbulence in the intertidal zones and interfered with natural processes, generally increasing erosion. Of course it's possible Japan has different coastal conditions.
Don't believe it, but the photos are fascinating. At the end of World War II a lot of military hardware was dumped along the coastlines of Australia. It was supposed to slow erosion. Studies in the 80's showed that these miscellaneous bits of concrete and metal just increased turbulence in the intertidal zones and interfered with natural processes, generally increasing erosion. Of course it's possible Japan has different coastal conditions.
Concrete tetrapods are supposed to slow coastal erosion.