The New Zealand Subantarctic Islands comprise the five southernmost groups of the New Zealand outlying islands. They are collectively designated as a UNESCO World Heritage Site. Most of the islands lie near the southeast edge of the largely submerged continent centred on New Zealand called Zealandia, which was riven from Australia 60-85 million years ago and from Antarctica between 130 and 85 million years ago.
The New Zealand Sub-Antarctic Islands consist of five island groups (the Snares, Bounty Islands, Antipodes Islands, Auckland Islands and Campbell Island) in the Southern Ocean south-east of New Zealand. The islands, lying between the Antarctic and Subtropical Convergences and the seas, have a high level of productivity, biodiversity, wildlife population densities and endemism among birds, plants and invertebrates.
The New Zealand Sub-antarctic Islands (NZSAI) encompasses five island groups that lie between latitudes 47° and 53° south; Snares Islands/Tini Heke, Bounty Islands, Antipodes Islands, Auckland Islands/Motu Maha and Campbell Island/Motu Ihupuku and the islands surrounding it. Including a total land area of 76,458ha, the marine area takes in 1,400,000 ha and constitutes one of New Zealand¡¯s remotest protected natural areas, including some of the world's least-modified islands.
The property lies between the Antarctic and Subtropical Convergences and the seas have a high level of productivity, biodiversity, wildlife population densities and endemism. While the NZSAI's are all located on the Pacific Tectonic Plate, the different geological history and age of each island group, and their geographical isolation from mainland New Zealand and from each other, has shaped the unique and remarkable biodiversity of the islands including distinctive plants, birds, invertebrates, marine mammals, fish and marine algae assemblages.
Particularly notable is the abundance and diversity of pelagic seabirds and penguins that utilise the islands for breeding. The property supports the most diverse community of breeding seabirds in the Southern Ocean. There are 126 species of birds, including 40 seabirds, eight of which breed nowhere else in the world. The islands support major populations of 10 of the world¡®s 22 species of albatross and almost 2 million sooty shearwaters nest on Snares Island alone.
Land birds also display a surprising diversity, considering the limited land area available, with a large number of threatened endemics including one of the world¡¯s rarest ducks. More than 95% of the world's population of New Zealand sea lion (formerly known as Hooker's sea lion) breed here and the marine environment provides critical breeding areas for the southern right whale.
The plant life of the NZSAI is notable for its diversity, special forms and unique communities, yet another outstanding example of the biological and ecological processes significant in the property. The Snares Islands and two islands in the Auckland group (Adams and Disappointment), are among the last substantial areas in the world harbouring vegetation essentially unmodified by humans or alien species. Another notable feature about the NZSAI is the land-sea interface and the close inter-dependence of both environments for many of the species ¨C the inclusion of the marine environment out to 12 nautical miles in the world heritage property recognises this.