The Most Remote Islands in the Atlantic Ocean Need Protection

This issue brief was updated on April 2, 2020, to reflect recently updated data about Tristan da Cunha.

Overview

In the remote waters of the South Atlantic Ocean lies the Tristan da Cunha archipelago, some 2,400 kilometres (1,491 miles) west of South Africa. A chain of four islands, Tristan da Cunha covers a small land area—about one-tenth the size of London—but it has an exclusive economic zone (EEZ) close to three times the size of the United Kingdom: 758,771 square kilometres (292,263 square miles). 

This secluded and relatively intact marine ecosystem is home to a range of birds, seals, and whales, including species found nowhere else on Earth. Tristan da Cunha’s waters serve as the feeding ground for the critically endangered Tristan albatross, the endangered Atlantic yellow-nosed albatross, and the vulnerable spectacled petrel. The islands provide a breeding environment for 85 percent of the world’s endangered northern rockhopper penguins, alongside multiple colonies of subantarctic fur seals.¹

To preserve these waters full of life, the Great British Oceans (GBO) coalition, made up of six nongovernmental organizations (NGOs) including The Pew Trusts, supports the establishment of a locally managed marine protection regime throughout the waters of the Tristan da Cunha archipelago. The Tristan Island Council has been leading these efforts, working with GBO, the Pew Bertarelli Ocean Legacy Project, the U.K. government, and island residents to promote the ecological and economic needs of the local community and preserve this valuable South Atlantic ecosystem.

Sue Scott

World’s most isolated islands

A chain of four islands makes up the Tristan da Cunha archipelago, which sits in the South Atlantic Ocean between Africa and South America. The main island of Tristan is home to the world’s most remote archipelago settlement, consisting of about 260 U.K. citizens.

In addition to Tristan, the other islands that form the U.K Overseas Territory of Tristan da Cunha are Gough, Inaccessible, and Nightingale. On Gough, a meteorological station leased to the South African government houses six staff members whose positions rotate annually. Inaccessible is an island formed by a long-extinct volcano, and Nightingale is an island formed by an active volcano that last erupted in 2004. Neither island is inhabited.

Geographic location of the Tristan da Cunha archipelago. Gough Island lies 400 kilometres (250 miles) southeast of Tristan da Cunha.

Biodiversity

Its secluded location means that the Tristan archipelago has a unique biodiversity with distinct conservational significance and immeasurable value for biological research. Collectively, Gough and Inaccessible are recognised as a UNESCO World Heritage Site. According to UNESCO, they serve as home to “some of the most important seabird colonies in the world. These include albatrosses, petrels, and penguins, reliant on the rich marine life surrounding them.”²

Four of the 25 species of seabirds³ found in Tristan breed nowhere else. Endangered Atlantic petrels and critically endangered Tristan albatrosses (known locally as Gony) are restricted almost entirely to breeding on Gough, but their numbers are declining fast. Because the species evolved on these islands with no terrestrial mammals present, the chicks are defenseless against rodents, which were introduced through whaling and sealing activities in the late 1800s.

The four main islands are breeding grounds for both endangered Sooty albatrosses (Peeoo) and the sub-species Atlantic yellow-nosed albatrosses (Molly). Vulnerable spectacled petrels reproduce only on Inaccessible, while vulnerable Inaccessible rails, the smallest flightless bird in the world, are endemic to the island. Fortunately, both Inaccessible and Nightingale remain free of mice and rats, which means the chicks hatched there are less at risk than those on Tristan.

Sue Scott

More than 85 percent of the world’s population of endangered northern rockhopper penguins (Pinnamins) breed in the archipelago, although Gough has had a recent decline in numbers. One theory is that the multiple colonies of subantarctic fur seals have caused this depletion, possibly because of competition for food or through predatory attacks.⁴ An estimated 80 percent of the world's subantarctic fur seals, about 300,000, live on Gough. Approximately 60,000 pups are born on the boulder beaches each year.⁵

Gough also has a lone breeding colony of Southern elephant seals.⁶ Although small, the population is slowly recovering from the hunting practices of the late 18th and early 19th centuries.

Sue Scott

Tristan has also been a stronghold for Shepherd’s beaked whales, an otherwise little-known whale species, and a nursery area for Southern right whales. At least nine other cetacean species are regular visitors, including fin whales and humpback whales.

Lobster fishery

Cape Town-based Ovenstone is the one operator licensed to commercially fish the abundant supply of rock lobster surrounding the islands and the Vema seamount, which is between South Africa and Tristan da Cunha. Ovenstone primarily serves markets in Japan and the United States. Local fishermen, through the Marine Stewardship Council (MSC) certified lobster fishery, deploy box traps from small boats around all four islands, hoop nets from powerboats off Tristan, and traps from the MFV Geo Searcher vessel at Gough, Inaccessible and Nightingale islands.⁷ The fishery provides 70 percent to 90 percent of the island’s income, which enables the community to be largely self-sufficient.

Scientists are concerned that rising sea temperatures caused by climate change could harm the lobster fishery. In response, the local community is exploring ways to diversify these fishing efforts, including possibly targeting mackerel-like wahoos on specific seamounts.

Sue Scott

Climate change resilience

Highly protected marine areas similar to the one proposed for Tristan da Cunha have been shown to mitigate the effects of climate change by building resilience into the ecosystem, which helps buffer against future uncertainty in the levels of commercial exploitation for fish stocks, as well as environmental fluctuations.⁸ Over time, strong protections should boost the ability of Tristan’s marine environment to cope with the impact of a changing climate, which would help safeguard the species that live there, and the people who depend on them.

Great British Oceans

Since 2015, Great British Oceans, a coalition of environmental NGOs that consists of the Blue Marine Foundation, Greenpeace-U.K., Marine Conservation Society, Royal Society for the Protection of Birds, Zoological Society of London, and The Pew Trusts, has advocated for the ambitious implementation of the U.K. government’s Blue Belt policy. Unveiled in 2016, the policy calls for protecting 4 million square kilometres (1,544,408 square miles) of ocean around the nation’s Overseas Territories. With support from the Pew Bertarelli Ocean Legacy Project, GBO has called for the protection of Tristan’s waters since 2015, and has partnered with the Island Council to study the best path forward. The process is ongoing, with a designation of a marine protection regime expected by 2020.

Ocean monitoring for a designated MPA

Effective monitoring and enforcement are critical to an MPA’s success. Remote monitoring can help solve the challenges posed by the large scale or remote location of a protected area. That task can be handled in part by capabilities such as Oversea Ocean Monitor, which was developed in a joint effort between Pew and Satellite Applications Catapult, known as “Project Eyes on the Seas.” It is now used by the international NGO OceanMind. The platform combines satellite data, fishing authorisations, and artificial intelligence to detect illegal, unreported, and unregulated (IUU) fishing for further assessment and investigation.

Authorities have already used Oversea Ocean Monitor extensively to monitor vessel activity in Tristan’s waters. The analyses have enabled the setting of baselines to inform future management decisions. In other Blue Belt sites, such as Pitcairn, the platform is being used to ensure that IUU fishing does not undermine marine conservation measures that ban commercial fishing.

Conclusion

In September 2016, the Tristan Island Council, in consultation with the U.K. government, committed to establish by 2020 a marine protection regime in the 758,771 square kilometre exclusive economic zone of the archipelago— and since that time has driven progress on its implementation. The Pew Bertarelli Ocean Legacy Project and GBO are working to support the local community’s efforts to enhance conservation of the marine environment of Tristan da Cunha, while also supporting the local need to maintain some sustainable fishing practices.

Establishment of a large protected area in these waters would be further fulfilment of the U.K. government’s commitment to create a 4 million square kilometre Blue Belt to protect its Ocean Territories, and would help cement the nation’s place as the world leader in marine conservation. In addition, the U.K. would further exceed the International Union for the Conservation of Nature’s recommendation—for nations to highly protect at least 30 percent of their marine habitats by 2030⁹—10 years ahead of schedule.

Endnotes

1. BirdLife International, “Eudyptes Moseleyi, ” The IUCN Red List of Threatened Species last modified August 2018, https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T22734408A132664126.en.
2. UNESCO, “Gough and Inaccessible Islands,” accessed March 5, 2020, https://whc.unesco.org/en/list/740.
3. S. Scott, “A Biophysical Profile of the Tristan Da Cunha Archipelago” (2017).
4. Ibid.
5. P. Ryan, Field Guide to the Animals and Plants of Tristan Da Cunha and Gough Island (Pisces Publications, 2007).
6. Tristan da Cunha Government & Tristan da Cunha Association, “Tristan Da Cunha Seals,” accessed March 5, 2020, December 30, 2015, https://www.tristandc.com/wildseals.php.
7. Marine Stewardship Council, “Tristan Da Cunha Rock Lobster,” accessed March 5, 2020, https://fisheries.msc.org/en/fisheries/tristan-da-cunha-rock-lobster/about/.
8. C.M. Roberts et al., “Marine Reserves Can Mitigate and Promote Adaptation to Climate Change,” PNAS 114 (2017): 6167-75.
9. IUCN, “IUCN Resolutions, Recommendations and Other Decisions” (2016).