Revegetation of the Ogasawara Archipelago

Some of the Ogasawara islands are populated with feral goats that were introduced to the island years ago and whose population has since exploded. As a result, the grazing of the animals has damaged some of the vegetation of Ogasawara, including endemic plant species. Due to the damage to the vegetation, parts of the land have been stripped bare. In addition to causing landslides that affect the mating of birds, as well coral and other sea life, this also damages the island landscape.

To stop this sort of damage in its tracks, the Tokyo Municipal Government strives to promote projects for the eradication of the goats and for revegetation in such places as Mukojima Island, Nakodojima Island, and Nishijima Island. The goat eradication programs on these islands ended in 2003, and new efforts started on Anijima in 2004. Revegetation efforts are underway on Nakodojima, where the damage was substantial.

On Minamijima, vegetation was damaged due to overuse of the island by tourists. Minamijima is an uninhabited island roughly 400 m (0.25 miles) wide, located in the Ogasawara Archipelago approximately 1 km (0.62 miles) to the southwest of the Chichijima. This beautiful island has a karst landscape, formed from the geological uplift and settling of calcareous earth, a phenomenon that is rare the world over. Of particular beauty is the Ogiike, a lagoon that is connected to the ocean and a tunnel-like rock formation. The cobalt-blue waters and white sand beach of the lagoon, which is shaped like an open fan, make this a popular spot for tourists. The ocean waters surrounding the island are also populated by whales and dolphins.

However, as a result of the many tourists who visit the island in search of its bountiful natural beauty, the natural environment has suffered in a number of ways. The island vegetation is trampled, which leaves the island's red soil bare, the unusual calcareous rock formations found on the island, known as lapies, are damaged, and the island is scattered with invasive vegetation from seeds carried to the island on the clothing and hair of visitors.
The Tokyo Metropolitan Government preserves this rare natural environment and runs projects that make efforts for revegetation.

The following activities are underway to preserve and restore the rare natural environment of Ogasawara:

1. The use of Minamijima is now governed by rules such as limits on the number of daily visitors to the island, the use of guided visits to the island, and the use of designated nature hike footpaths.
   Ecotourism in Tokyo
2. In places where vegetation has already been lost and the earth is bare, efforts are underway to recover the lost vegetation.
3. Invasive vegetation, thought to have been carried to the island as seeds clinging to the clothing and hair of visitors, is being eradicated.
4. Ongoing monitoring surveys are conducted to ensure that the abovementioned usage of and operations on the island are appropriate.
   

Some specific details of the revegetation operations are as follows:

1. Revegetation efforts are currently being made by transplanting grasses from within the island as a measure for preventing soil erosion and landslides. This work targets areas of bare earth and areas where vegetation has been trampled and destroyed.
2. Experimentally, stones from withing the island were installed as stepping stones for some of the nature observation trails where the ground was stripped bare. This is a part of our efforts to prevent further destruction of vegetation due to trampling, and to aid in revegetation.
3. Work to eradicate invasive vegetation carried to the island by people is also underway.