Ogasawara

Ogasawara National Park was established on 16 October 1972 and protects 66.29 km² of the archipelago of the same name, in the north-western Pacific some thousand kilometres south of Tokyo, of which it administratively forms part. In 2011 UNESCO inscribed the Ogasawara Islands on the World Heritage List as a natural property: a serial property of five components spread over some 400 kilometres from north to south that includes more than thirty islands of the Mukojima, Chichijima and Hahajima groups, plus Kita-iwoto, Minami-iwoto and the isolated Nishinoshima. The property totals 7,939 hectares, of which 6,358 are terrestrial and 1,581 marine. Only two islands are inhabited: Chichijima and Hahajima.

The islands emerged from an ancient submarine volcano along the Izu-Ogasawara arc-trench system and have never been joined to a continent. Everything that lives on them descended from organisms that arrived by chance: carried by birds or by the wind, swept along by currents or clinging to driftwood. Isolated for millions of years, those colonists diversified in place. The result is an evolutionary laboratory of the first order: more than 440 native vascular plant species with endemism rates reaching 70 % among the woody plants, around 25 % endemism among the insects and, above all, more than a hundred species of land snail of which more than 90 % are found only in the archipelago.

That snail fauna is the central argument for the inscription. Ogasawara shows adaptive radiation at a very fine scale, with distinct species between neighbouring islands and sometimes within a single island, which makes it a key case study for understanding speciation and ecological diversification; to that is added the low extinction rate in these groups. The landscape is dominated by subtropical forest and sclerophyllous scrub, ringed by vertical cliffs above a sea of a blue so distinctive that it has a name of its own, the "Bonin Blue". The fragility of the system is extreme: simply carrying insects on clothing or footwear between islands is enough to disturb it, and management includes strict biosecurity protocols and breeding programmes for threatened snail and tiger beetle species.