The Pitcairn Islands expedition

The Pitcairn Islands group is a British Overseas Territory in the South Pacific. The four islands that comprise it (Pitcairn, Henderson, Ducie and Oeno) provide habitat for various endemic plant and bird species, as well as important seabird colonies. Pitcairn is one of the world’s most remote inhabited islands, with a population of around 50 islanders, some of whom descend from sailors on board the HMS Bounty during the famous mutiny of 1789.

In September 2016, the United Kingdom created one of the largest fully protected marine reserves in the world, spanning about 830,000 square kilometres across 99% of the Pitcairn Islands exclusive economic zone. The reserve hosts 1,249 identified marine species including endangered humpback whales (mothers and calves), sharks, more than 200 species of fish, and a coralline alga that is the world’s deepest known living plant species.

Since 2016, the UK Government Blue Belt Programme has assisted Pitcairn Islanders with researching and monitoring a marine environment about which very little is known. Underwater surveys carried out by volunteer islanders in collaboration with scientists from the Centre for the Environment, Fisheries and Aquaculture Science (Cefas) found that Ducie and Henderson have some of the highest marine biodiversity in the subtropics. The rare crystal-clear waters in the area create the prime conditions for coral reefs to stretch to deeper, cooler waters compared to elsewhere in the Pacific Ocean. These mesophotic reefs (30 – 150 metres water depth) support healthy populations of reef sharks, which were observed in two thirds of all underwater surveys.

The areas around the island have been explored to some extent over the past few years, but further offshore there are 69 known seamounts, expected to provide important habitat, feeding and breeding grounds for aquatic predators, fish, and corals; but almost no data on the biodiversity they support. One of these is the still-active Adams Seamount located above the Pitcairn Hotspot, about 90 kilometres west-south-west of Pitcairn Island.

In February 2023, aboard the MV Silver Supporter, Senior Marine Advisor Simeon Archer-Rand and fellow scientists at Cefas, along with Pitcairn Islander volunteers, and Professor Murray Roberts and Jason Cleland from the University of Edinburgh – in collaboration with Deputy Governor of the Pitcairn Islands Alasdair Hamilton and the Government of the Pitcairn Islands – will be among those conducting the first biodiversity assessment of the upper Adams Seamount. This will include the use of baited remote underwater video systems (BRUVS), BlueROV2 video systems, eDNA sampling, and carbonate chemistry sampling, to further inform the Pitcairn Islands Marine Protected Area Management Plan 2021-2026 and, on a broader scale, to better understand mesophotic reefs and seamount ecosystems in the changing environment of the South Pacific.