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National Parks · Tokyo

Ogasawara National Park

小笠原国立公園おがさわらこくりつこうえんOgasawara Kokuritsu Kōen

Evolution in isolation, a day's voyage from Tokyo

Ogasawara National Park protects the Ogasawara (Bonin) Islands, a scattered chain of oceanic islands in the Pacific some 1,000 km south of Tokyo that have never been connected to a continent. Designated in 1972 and inscribed as a natural World Heritage Site in 2011, they are an outstanding example of evolution on isolated islands.

Area: 66.29 km²National park · 1972UNESCO World Heritage · 2011

Overview

The Ogasawara Islands stretch over some 400 km of the western Pacific, from the Mukojima group in the north through Chichijima and Hahajima to the Kazan (Volcano) Islands in the south. More than 30 islands make up the archipelago, but only Chichijima and Hahajima have civilian populations. The national park covers much of their land and surrounding waters, including the uninhabited Mukojima group, Minami-Iōtō and the growing volcanic island of Nishinoshima.

The islands are oceanic: they formed from submarine volcanoes on the Izu-Bonin-Mariana arc and were never linked to a landmass. Their plants and animals descend from the few species that arrived by wind, sea or birds, and many evolved into new endemic forms. This process of adaptive radiation, most spectacularly among the land snails, was the reason for UNESCO's inscription in 2011.

Designated as a national park in 1972, four years after the islands' return from United States administration, Ogasawara is one of the smallest national parks in land area but among the most remote. Its subtropical forests, coral reefs, white beaches and deep blue sea make it a destination for diving, whale watching and nature tours, under strict rules to protect its fragile ecosystems.

Landscape and formation

The northern islands, Mukojima, Chichijima and Hahajima, are the remains of an island arc formed about 48 million years ago, in the earliest phase of subduction of the Pacific plate. Their rocks include boninite, a rare lava named after the Bonin Islands, which records the birth of a subduction zone and draws geologists from around the world.

Chichijima and Hahajima are eroded and hilly, reaching 462 m at Chibusa-yama on Hahajima. Raised limestone forms karst on Minamijima, where a drowned doline has become the enclosed bay of Ōgiike, and at Sekimon on Hahajima. The Kazan Islands in the south are young, active volcanoes: Minami-Iōtō rises steeply to 916 m with untouched cloud forest, and Nishinoshima has grown dramatically through eruptions since 2013.

Highlights

  • Chichijima

    父島Chichijima

    The main island with Futami port, beaches such as Kopepe and Kominato, and viewpoints like Mount Asahi and Chūōsan.

  • Hahajima

    母島Hahajima

    A quieter island south of Chichijima, with humid cloud forest on Chibusa-yama and the endemic Hahajima honeyeater.

  • Minamijima

    南島Minamijima

    A small karst island off Chichijima with the enclosed Ōgiike beach, visited only with licensed guides.

  • Mukojima group

    聟島列島Mukojima rettō

    Uninhabited northern islands, where short-tailed albatrosses have been re-established.

  • Minami-Iōtō

    南硫黄島Minami-Iōtō

    A steep, uninhabited volcanic island with untouched forest, closed to visitors as a strict nature reserve.

  • Nishinoshima

    西之島Nishinoshima

    A volcanic island that has grown many times its former size through eruptions since 2013, a natural laboratory of colonisation.

Ecology

Isolation produced a unique but species-poor biota. Of the native vascular plants, over a third are endemic, and the dry scrub forest of Chichijima and Hahajima, dominated by species such as Distylium lepidotum, has no counterpart elsewhere. The land snails have radiated into more than 100 species, most found only here, some living in trees and others on the ground.

Native mammals are limited to the Bonin flying fox, and native birds include the Hahajima honeyeater (Bonin white-eye) and the Ogasawara buzzard. The seas hold coral reefs, Japan's largest green turtle nesting beaches and rich cetacean life. Introduced goats, rats, cats and the green anole lizard have caused great damage; eradication and control programmes are a major part of park management.

Flora

  • Dry scrub forest

    Low, evergreen forest on thin soils of Chichijima and Hahajima, rich in endemic shrubs and trees.

  • Munin-nobotan

    ムニンノボタンMunin-nobotan

    An endemic melastome with white flowers, reduced to a few wild plants and restored from cultivation.

  • Munin-tsutsuji

    ムニンツツジMunin-tsutsuji

    A white-flowered endemic azalea once reduced to a single wild plant on Chichijima.

  • Tako-no-ki (Pandanus boninensis)

    タコノキtako-no-ki

    An endemic screw pine with stilt roots, a symbol of the islands.

  • Asahi-ebine

    アサヒエビネAsahi-ebine

    A yellow-flowered endemic orchid of the humid forests of Hahajima.

Fauna

  • Land snails

    Over 100 species, most endemic; the genus Mandarina shows adaptive radiation into ground and tree-dwelling forms.

  • Bonin flying fox

    オガサワラオオコウモリOgasawara-ōkōmori

    The islands' only native land mammal, a fruit bat protected as a Natural Monument.

  • Hahajima honeyeater

    メグロmeguro

    A white-eye with a black mask, found only on the Hahajima group, and a Special Natural Monument.

  • Green turtle

    アオウミガメaoumigame

    Nests on the beaches from spring to summer; Ogasawara is its largest nesting site in Japan.

  • Humpback whale

    ザトウクジラzatō-kujira

    Arrives in winter and spring to breed and calve around the islands.

Culture

The islands were uninhabited until the 19th century. A Japanese expedition surveyed them in 1675, but the first settlers, in 1830, were a small group of Europeans, Americans and Pacific Islanders from Hawaii, led by Nathaniel Savory and Matteo Mazzaro. Japan asserted sovereignty in 1876, and settlers from Hachijō-jima and the mainland followed. The descendants of the first settlers still live on Chichijima, and the island's culture mixes Japanese, Western and Micronesian elements, from Bonin English words to the South Sea dance (Nanyō odori).

The Second World War brought forced evacuation of the civilian population in 1944 and the Battle of Iwo Jima in 1945. The islands remained under United States administration until their return to Japan on 26 June 1968; that date is celebrated each year as the Return Festival. War relics, from gun emplacements to sunken ships in Futami bay, are part of the landscape.

  • Ogasawara Visitor Center

    小笠原ビジターセンターOgasawara Bijitā Sentā

    Visitor centre at Futami port on the islands' nature, history and rules for visitors.

  • Ogasawara World Heritage Center

    小笠原世界遺産センターOgasawara Sekai Isan Sentā

    Centre on Chichijima presenting the islands' endemic species and conservation work.

  • Ogasawara Marine Center

    小笠原海洋センターOgasawara Kaiyō Sentā

    Turtle-conservation facility on Chichijima where green turtles are studied and hatchlings raised.

History

  1. c. 48 million years ago

    Volcanic activity at a newly formed subduction zone builds the islands of the Bonin arc.

  2. 1675

    A shogunate expedition surveys the islands and names them the 'uninhabited islands' (bunin-jima).

  3. 1830

    The first permanent settlers arrive on Chichijima from Hawaii.

  4. 1876

    Japanese sovereignty over the islands is internationally acknowledged.

  5. 1944–45

    Civilians are evacuated; the Battle of Iwo Jima is fought in the Kazan Islands.

  6. 1968

    The islands return from US administration on 26 June.

  7. 1972

    Ogasawara National Park is designated on 16 October.

  8. 2011

    UNESCO inscribes the Ogasawara Islands as a natural World Heritage Site.

  9. 2013

    Eruptions begin that greatly enlarge Nishinoshima.

Through the seasons

Spring

Humpback whales remain until about April; warm, pleasant weather and the start of the turtle-nesting season.

Summer

Hot and sunny with calm seas, the peak for diving, snorkelling and turtle hatching; typhoons can disrupt shipping.

Autumn

Still warm sea and fewer visitors; typhoons remain possible into October.

Winter

Mild, around 18 to 20 °C, with the return of humpback whales from about February; the islands' New Year is the first in Japan to celebrate the year's first swim in the sea.

Routes and trails

  • Mount Asahi and Chūōsan on Chichijima

    Short hikes to viewpoints over the island and the sea.

  • Chibusa-yama on Hahajima

    A forest trail to the highest point of the Ogasawara group, through humid forest with endemic plants.

  • Minamijima guided visit

    Boat trips with licensed guides to the karst island and Ōgiike beach, subject to rules and daily limits.

  • Whale and dolphin cruises

    Boats from Futami port for humpback whales in season, sperm whales offshore and dolphins year-round.

  • Hahajima Sekimon forest

    A hike into the limestone forest of Sekimon, permitted only with a registered guide.

Practical notes

  • Allow at least six days for a trip, as the ship sails roughly once a week and spends a few days in port before returning.
  • Clean shoes, clothes and equipment at the seed-removal mats on arrival and between islands; do not bring plants, soil or animals.
  • Several areas require licensed guides and have visitor limits; book tours in advance and follow the Ogasawara rules for visitors.
  • Medical facilities are limited and evacuation to Tokyo depends on the Self-Defense Forces; carry travel insurance and avoid unnecessary risks.
  • Sun protection and water are essential on hikes; many trails are exposed and hot.

Frequently asked questions

How do you get to Ogasawara?

There is no airport. The passenger ship Ogasawara-maru sails from Takeshiba pier in Tokyo to Futami port on Chichijima in about 24 hours, usually about once a week; a smaller ship continues to Hahajima in around two hours.

Why are the islands called the 'Galápagos of the Orient'?

Because the islands rose from the ocean floor and were never joined to land, every plant and animal arrived across the sea and evolved in isolation. Over a third of the native plants and more than 90 percent of the land snails are found nowhere else.

Where does the name Bonin come from?

It derives from an old Japanese reading, bunin or munin, meaning 'no people', as the islands were uninhabited when first recorded. Ogasawara refers to a legendary 16th-century discoverer, Ogasawara Sadayori.

Can visitors go anywhere on the islands?

Several sensitive areas, including Minamijima and parts of Hahajima's Sekimon forest, may only be visited with licensed guides and under visitor limits. Visitors must also clean shoes and gear to avoid carrying seeds and invasive species between islands.

When can whales be seen?

Humpback whales visit the islands to breed from about February to April, and sperm whales can be seen year-round in deep water off Chichijima; dolphin watching and swimming tours run throughout the year.

Sources

  1. 1.小笠原国立公園 (opens in a new tab) — 環境省
  2. 2.国立公園の概要 (opens in a new tab) — 環境省
  3. 3.Ogasawara National Park (opens in a new tab) — Ministry of the Environment, Japan
  4. 4.Ogasawara Islands (opens in a new tab) — UNESCO World Heritage Centre

Editorial team · Published: