Land area: 6,629 ha
Designated on October 16, 1972
Tokyo, the capital of Japan, is generally recognized as a giant metropolis with forests of buildings. However, subtropical islands in the southern sea are also a part of Tokyo.
The Ogasawarashoto Islands are called the "Galapagos of the East" because they are remote from the main island and blessed with abundant nature including many endemic species.
The islands are full of the charms of nature.
The Ogasawarashoto Islands lie 1,000 – 1,250 km south-southeast from Tokyo which is located in the center of the main island of Japan. The national park consists of four groups of islands – Mukojima (Groom), Chichijima (Father), Hahajima (Mother) and Kazanretto Islands from north to south. Iojima and Minami-Iojima Islands are not included in the park.
Mukojima, Chichijima and Hahajima Islands were formed when the sediment of undersea volcanoes was upheaved. After old volcanic islands were submerged by the sea because of erosion, they were upheaved again in the Quaternary and formed islands. The peaks of these islands are in similar heights because of the erosion by waves when the islands were undersea. In Chichijima, pillow lava can be found in some places. This is solidified lava that was blown off into the sea where it accumulated. It indicates that the island was an active volcano when it was under the sea. Having been weathered and eroded by waves, these islands constitute a unique and diversified terrain.
Separated from these three groups of islands, Kita-iojima and Nishinoshima Islands are volcanic islands whose peaks stand out above the sea. While Kita-Iojima Island is a small round island of 2 km in diameter, it rises from the shore forming a cone the top of which is 792 m above sea level.
The Ogasawarashoto Islands consist of isolated islands which have never been connected to a continent since they were formed. As there are no land animals on the islands, the number of species living here is limited. However, there is varied vegetation, supposedly about 40% of which are endemic species. Many of them have words such as Ogasawara, Munin (uninhabited) and Shima (island) in their names.
As these islands have a closed environment, they are vulnerable to the influence of exotic animals and plants. As a result, quite a few species have become extinct or are endangered. For example, the number of naturally growing shimahozakiran (Malaxis boninensis) and muninnobotan (Melastoma tetramerum) has been decreasing and there is a concern that they are at very high risk of extinction. Ogasawaraguwa (Morus boninensis), an endemic species on Hahajima Island, is a rare kind of hydrarch tree.
Regarding the fauna, the island chain is a habitat for bonin flying fox. It is the only indigenous mammal on the islands and very valuable as its population is small. In the islands, there are many goats which have gone wild. These goats and some other non-native species are designated as animals to be exterminated as they cause damage to Ogasawara's native species. The critical situation is the same for birds. Ogasawara islands honeyeater, which is the only endemic bird native to the Ogasawara, now live only on the Hahajima Island Chain.
This area enjoys exquisite submarine landscapes. As coral grows in some places, schools of tropical fish in bright colors can be seen.