In order to secure Japan's rights over its EEZ, which is twelve times the size of its national territory, there is a need to monitor all ships' movements in the area. Effective monitoring of water-based activities means the use of sound. As variations in acoustic transmission are dependent on marine conditions, the establishment of a system for predicting these changes and developing a marine object monitoring Low-frequency active system is indispensable in the securing of Japan's rights in its EEZ.

Although Oshima-Ohshima, lying 50km off Matsumae in Hokkaido, is Japan's largest uninhabited island, its existence is largely unknown. It is the northern most breeding ground for the Streaked Shearwater in Japan. From the Edo period to the present, the Streaked Shearwater has survived volcanic eruptions, capture by man, direct predation by the brown rat, and indirect pressure by the destruction of its nests by the Japanese white rabbit. It is now, however, on the brink of extinction.

Although we are an island nation, parents, schools, and the government have told the children who will one day be the leaders of Japan that the ocean and rivers are dangerous and should be avoided, depriving these children of opportunities and places to learn about nature. Although many places are indeed dangerous, we should teach children to become familiar with the ocean and yet know how to protect themselves, to appreciate its pleasures and beauties as well as its forbidding sides, how to seek out places of safety and deal with trouble. We should instill in our children a sense of adventure and hardiness.