The site, located in the south Atlantic, is one of the least-disrupted island and marine ecosystems in the cool temperate zone. The spectacular cliffs of , towering above the ocean, are free of introduced mammals and home to one of the world’s largest colonies of sea birds. Gough Island is home to two endemic species of land birds, the gallinule and the Gough rowettie, as well as to 12 endemic species of plants, while Inaccessible Island boasts two birds, eight plants and at least 10 invertebrates endemic to the island.

Brief synthesis

are two extraordinary uninhabited oceanic islands that have remained relatively undisturbed, and are therefore of special conservation significance. Gough Island is one of the largest cool-temperate oceanic islands in the world that remains close to pristine, having been spared most introductions of invasive species that have decimated unique island biodiversity elsewhere. While Inaccessible Island is smaller, it is of no lesser significance, housing a number of species endemic to this tiny speck in the South Atlantic Ocean.

The spectacular cliffs of each island, towering above the ocean, host some of the most important seabird colonies in the world. These include albatrosses, petrels, and penguins, reliant on the rich marine life surrounding them. Gough Island is home to two endemic species of land birds as well as twelve endemic plant species. Inaccessible Island also boasts three endemic subspecies and one endemic species of land bird – the Inaccessible Rail, which is the smallest flightless bird in the world –, and some eight endemic plant species. This island is also the only place where the Spectacled Petrel breeds, while the Atlantic Petrel and the Tristan Albatross are almost entirely restricted to breeding on Gough. The islands’ undisturbed nature makes them particularly valuable for biological research. 

Criterion (vii):

Two eroded remnants of long-extinct volcanos, display outstanding natural beauty. Their precipitous cliffs around much of the coastline, covered with breeding seabirds, are highly spectacular.

Criterion (x):

Gough and Inaccessible Island represent two of the least disturbed cool-temperate island ecosystems in the South Atlantic Ocean, and are internationally important for their colonies of some 22 species of seabirds, several of which only breed here. They also support a number of endemic species and subspecies of land birds, including the Gough Moorhen (a flightless rail) and the Gough Bunting, both endemic to Gough, and the Inaccessible Rail, the smallest flightless bird in the world, endemic to Inaccessible Island. This island forms part of the Tristan Endemic Bird Area, and Gough has been designated as its own Endemic Bird Area by BirdLife International. Key seabird species include the Atlantic Petrel, Spectacled Petrel, Tristan Albatross, Sooty Albatross, the subspecies of Yellow-nosed Albatross, and the Northern Rockhopper Penguin. The islands also support some 40 plant species (including vascular plants, bryophytes and lichens), which are endemic to the Tristan da Cunha island group, including a number of which are endemic to Gough and/or Inaccessible Islands. 

Integrity

are one of the most pristine environments left on earth. These remote South Atlantic islands, surrounded by protected marine areas of 12 nautical miles, are home to unique assemblages of plants and animals effectively isolated from the rest of the world by 2,000 nautical miles of open ocean and some of the world’s fiercest weather.

Inaccessible Island is one of the few oceanic islands with no introduced mammals, whereas Gough has introduced House Mice, significant predators of seabird chicks, and will, if uncontrolled, gradually reduce the biological value of the site. Sagina procumbens, an aggressive alien plant accidentally introduced during the 1990s, and a few other introduced plant species such as New Zealand Flax, could also degrade the integrity of the property if current control measures prove inadequate. However, the virtually undisturbed condition of makes them particularly valuable for conservation and biological research. The islands are strictly managed as a Wildlife Reserve, IUCN Protected Area category 1, with research and weather monitoring the only activities permitted. 

Protection and management requirements

Tristan da Cunha (including ) is a United Kingdom Overseas Territory forming part of the UK Overseas Territory of St Helena, Ascension, and Tristan da Cunha, and is administered by a UK-appointed representative, with support from an elected Island Council. The management authority is the Tristan Conservation Department, which employs permanent staff members supported by casual workers and the Tristan “Darwin team”. The Tristan da Cunha Environment Charter outlines the environmental management commitments of the UK Government and the Government of Tristan da Cunha, and serves as a framework policy to guide the development of management policies and plans.

The Conservation of Native Organisms and Natural Habitats (Tristan da Cunha) Ordinance 2006 gives statutory force to the general protection of the property, which is classified as a Nature Reserve. This provides strict protection to all native organisms and makes it an offence to transport any native organisms between islands or to introduce any non-native organisms. In parallel to this, the Tristan da Cunha Fisheries Limits Ordinance 1983 provides for the control of commercial fishing activity within the Tristan da Cunha exclusive economic zone, up to 200 nautical miles offshore from the islands.

The World Heritage Site Management Plan focuses on identifying priority actions for the conservation of the property over a five year period, and does not supersede the two existing Management Plans for . The Tristan da Cunha government has also developed a Biodiversity Action Plan that relates closely to the World Heritage Site Management Plan but covers the entire island group and its seas. A detailed operating/conduct code developed by the Tristan Government provides guidelines on best practice to be observed by visitors and managers of the two islands. Separate zoning strategies for have been developed. On Gough, there are Logistic, Marine, Scientific research, and Conservation zones; on Inaccessible there are Accommodation, Natural, Wilderness, and Marine zones. Within these various areas, defined in detail in the respective Management Plans, certain activities are constrained or allowed. A single zoning strategy is needed covering the whole World Heritage property, including the marine area.

The UK is a State Party to the Ramsar and Bonn Conventions; the UN Convention on Biological Diversity; and the Agreement on the Conservation of Albatrosses and Petrels (ACAP).These conventions provide international obligations for the conservation of albatrosses and petrels, including the protection of important habitats and species. By agreement with the Tristan da Cunha government, these international conventions have been extended to cover Tristan da Cunha, and therefore the Tristan Government is obliged to fulfil their requirements locally.

In common with many island ecosystems around the world, alien invasive species are the most important immediate threat to the ecology of . House Mice were introduced to Gough Island in the 19th century, and are known to have adverse impacts on both terrestrial and marine birds on Gough. In partnership with the Royal Society for the Protection of Birds, a mouse eradication programme as well as programmes to control or eliminate invasive plant species including Sagina procumbens and New Zealand Flax, are underway. Protocols are in place to ensure that no new introductions occur.