Gough and Inaccessible Islands have been designated UNESCO World Heritage Site 740.
Full text from the UNESCO description

World Heritage Site 740 : Gough and Inaccessible Islands

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 Gough and Inaccessible Islands, 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.

Gough Island - see also Gough Island page
Outstanding Universal Value

Brief synthesis

Gough and Inaccessible Islands 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 volcanoes, Gough and Inaccessible Islands 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.

Inaccessible Island - See also Inaccessible Island page

Integrity

Gough and Inaccessible Islands 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 Gough and Inaccessible Islands 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 Gough and Inaccessible Islands) 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 Gough and Inaccessible Islands 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 Gough and Inaccessible Islands. 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 Gough and Inaccessible Islands 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 Gough and Inaccessible Islands. 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.

Long Description

Gough Island, a volcanic island in the central South Atlantic, is dependent on British Tristan da Cunha, midway between the southern tip of Africa and South America and it includes the 14 km 2 Inaccessible Island, whereas the marine area is extended to 12 nautical miles.

Gough Island is the least-disturbed major cool temperate island ecosystem in the South Atlantic, and one of the most important seabird colonies in the world. The island is scenically beautiful with spectacular sea cliffs round much of the coastline. Two endemic land birds are found: the Gough moorhen and the Gough finch. Gough is in the Tristan da Cunha Priority One Endemic Bird Area, as defined by BirdLife International. Its undisturbed nature makes it particularly valuable for biological research, which, with weather monitoring, is the only other activity permitted on the island.

Inaccessible Island's values complement those of Gough Island. It is also largely pristine and is one of the few temperate oceanic islands without introduced mammals. It has two birds, eight plants and 10 invertebrates found nowhere else, 70 terrestrial plant and animal species are restricted to the islands and 60 marine species are endemic to the island group .

Gough Island has had a long and complicated volcanic history. Five major phases of activity have left distinctive rock masses. Numerous different centres helped to build up the land mass that now exists, and some of them continued activity into comparatively recent tines; the most recent minor eruption probably took place about 2300 years ago. No activity has been recorded since men began to visit the island.

Gough Island is the eroded summit of a Tertiary volcanic mass separated from the volcanic formations of the Tristan group. The island is mountainous, with steep cliffs forming much of the coastline, and an undulating plateau rising to 910 m above sea level. The eastern side of the island is dissected by a series of deep, steep-sided valleys known as glens, which are separated by narrow, serrated ridges. The western side of the island consists of rounded slopes, extending from the central plateau to western sea cliffs. The southern area of the island is the only land below 200 m. Boulder beaches are found beneath the cliffs, and there are numerous offshore islets, stacks and rocks - most within 100 m of the main island, and none at a distance greater than 1 km.

Gough Island has been described as a strong contender for the title 'most important seabird colony in the world', with 54 bird species recorded in total, of which 22 species breed on the island, 20 being seabirds. Four species are threatened. There are three endemic genera. About 48% of the world's population of the northern rockhopper penguin - Eudyptes chrysocome moseleyi - (classed as vulnerable) breed on Gough. Atlantic petrel - Pterodroma incerta - (also vulnerable) is endemic to Gough and the Tristan group of islands. Gough is also a major breeding site of the great shearwater - Puffinus gravis - with up to 3 million pairs breeding on the island. The main southern ocean breeding sites of little shearwater - Puffinus assimilis - are Tristan da Cunha and Gough Island, with breeding pairs numbering several million. The endangered wandering albatross - Diomedea dabbenena - is virtually restricted to Gough, with up to 2,000 breeding pairs. The last survivors of the southern giant petrel - Macronectes gigantous - also breed on Gough, with an estimated 100-150 pairs, is classed as vulnerable. Gough moorhen - Gallinula comeri - (also vulnerable) is found in fern bush vegetation areas. Estimates of population size vary from 300-500 pairs to 2,000-3,000 pairs. About 200 pairs of Gough finch - Rowettia goughensis - (vulnerable) have been recorded, although recent estimates suggest that there may be 1,000 pairs.

Gough Island houses two endemic species of land birds, the gallinule and the Gough rowettie, as well as to 12 endemic species of plants, whereas Inaccessible Island has two birds, eight plants and at least ten invertebrates endemic to the island. The marine area can be split into two distinct algal zones. Subantarctic fur seal and southern elephant seal are the only two native breeding mammals. The former breeds at beaches all round the island, whereas the latter are restricted to the island's sheltered east coast. Two other marine mammals are found within the reserve, southern right whale and dusky dolphin. Reptiles, amphibians, freshwater fish and native terrestrial mammals are absent from the island, although the introduced house mouse is widespread and abundant. The largest stacks support vascular plants and breeding birds.

The Tristan archipelago was discovered by Tristão d'Ancunha in 1506, was visited periodically by Dutch sailors and annexed to Britain in 1816. Both Gough and Inaccessible Islands were exploited by sealers in the last decade of the 18th and early decades of the 19th centuries. Sealers stayed on Gough Island for considerable periods, subsisting on fish, seabirds, eggs, wild plants and cultivated potatoes (no longer present on Gough). Whaling occurred between 1830 and 1870, and Tristan islanders visited Inaccessible between the 1850s and 1890s to harvest seals and the introduced goats and pigs, but the islands remained uninhabited.

Gough Island has never been permanently populated and the only inhabitants are the six scientists working at the meteorological station which has functioned since 1956. The only man-made structure on the island is the meteorological station and its associated generators, storerooms, communication facilities and helicopter landing site. Inaccessible Island has been uninhabited except for a two-year farming settlement 1936-38 but has been regularly visited from Tristan for birds, eggs, driftwood, guano and apples. The last pigs, sheep and cattle were removed in the 1950s. Since 1949 its coastal waters within 50nm are fished for the Tristan rock lobster - Jasus tristani - by a single licensee. This, with crayfish fishing, is the island groups' main source of revenue.

See also UNESCO's World Heritage Convention Website :whc.unesco.org which can be visited for more background information.