Great progress has been made on strengthening the biosecurity of Tristan da Cunha thanks to the RSPB’s involvement in a three year, Darwin Plus funded project. UK Overseas Territories Project Officer, David Kinchin-Smith explains why biosecurity is so important for remote islands like Tristan, and some of the new biosecurity measures that are protecting Tristan’s community and wildlife.

What is biosecurity?
Biosecurity is about taking measures to prevent the spread of animals, plants or other organisms to areas where they aren’t naturally found.

With our increasing reliance on transporting people and goods all around the world, many species have been spread to new areas where they have had a devastating impact on health, food production, economies and native wildlife. Biosecurity is therefore very important and especially so in remote and isolated communities.

Protecting one of the remotest places on earth
Located in the middle of the South Atlantic, over 2,000 km from the nearest land, Tristan da Cunha boasts the title of the most remote inhabited archipelago in the world. Being so isolated, the islands are a haven for seabirds, marine life, land birds and other wildlife including species that are found nowhere else on the planet.

The small community of around 250 people are also reliant on the natural resources of the islands (particularly crayfish), and so it is vital that they are protected.

Being so remote makes it difficult for new organisms to reach the islands, but their impact can be significant should they arrive. Nowadays, it is becoming increasingly easy to travel to previously inaccessible places such as Tristan, meaning biosecurity has never been more important for these secluded places.

The damage of invasive species
The islands have already fallen victim to the damaging effects of introduced species. House mice were accidentally introduced to Gough Island (part of the Tristan da Cunha archipelago) in the 19th century by sealers. These mice have been responsible for the loss of an estimated two million seabird eggs/chicks each year. This impact has in the short term been reduced markedly by the mouse eradication attempt in 2021, but given the attempt was unsuccessful, mouse predation will likely reassert itself in the future.

More recently, the brown soft scale insect has arrived on the islands. This common garden visitor could simply have arrived on the sole of someone’s shoe. However, it has rapidly spread in recent decades and is destroying native Phylica forest habitat on the islands. Critically Endangered species like the endemic Wilkins’s Bunting, are reliant on the fruits of the Phylica tree – if we lose the forest, we lose this species as well.

Celebrating new biosecurity measures
Over the last three years, there has been significant progress towards strengthening Tristan’s biosecurity:

Tristan now has a designated Biosecurity Officer to oversee the unloading of passengers and cargo on the island to ensure nothing novel is brought onto the island, for example in a tyre tread or caught in a Velcro fastening.

A new building has been built on the island which provides the Conservation Department with a bio-secure area to carry out inspections as well as lab space for identifying any hitchhiking species should they be detected upon arrival.

A Darwin Plus project also involved working closely with suppliers and vessel operators in Cape Town, providing equipment and bespoke training to ensure biosecurity standards remain high along all potential routes by which a novel species could be introduced.

This positive progress is underpinned by Tristan’s new Biosecurity Ordinance which was passed earlier this year and gives the islanders the legal framework to protect their special islands.

Biosecurity Officer, Julian Repetto (far left) and Biosecurity Assistant Wayne Swain (far right) standing in front of Tristan’s new Biosecurity Facility © Dr Jill Key

Safeguarding Tristan for the future
In June, an end-of-project conference was held for all stakeholders involved in Tristan’s biosecurity project. Not only did everyone commit to placing a greater emphasis on biosecurity going forwards, but there was also agreement from all to hold a meeting to review progress each year and to continually improve biosecurity protocols.

The SA Agulhas II moored in Cape Town – this vessel makes an annual voyage to Tristan and Gough, taking passengers and cargo to both islands © David Kinchin-Smith.

The accidental introduction of new species will forever remain a risk to the Tristan da Cunha archipelago, and there is still much work to do. However, there has been considerable progress made over the last three years and the islands are better protected than they’ve ever been. The future certainly looks brighter for this special community and the spectacular biodiversity which lives there.

Funding for the project ‘Strengthening biosecurity for remote Territory communities and their World Heritage’ was provided by the Darwin Plus, UK Government grant scheme. Funding provided by the Government of Tristan da Cunha and the GB Non-Native Species Secretariat (GB NNSS) was also key to the success of the project.

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