Somewhere in the Seychelles, an undersea symphony is playing. The tide’s ebb and flow beat the percussion as endangered green and critically endangered hawksbill turtles haul themselves beachward to secrete their eggs in the sand. Ghost crabs scuttle shoreward and are plucked by seabirds that soar octaves above. In the mangrove roots that tangle like wayward staves, sicklefin lemon and blacktip reef shark pups are gifted a nursery where they can grow large and strong. Reef manta rays dance across the corals that house humphead wrasse and gobies, butterflyfish and pipefish. D’Arros Island and St Joseph Atoll stand out as small but hopeful havens, a protected sanctuary in the Seychelles’ far-flung Outer Islands. It is a near-pristine refuge crammed with life, a living laboratory that shows us what the ocean might look like if we give it space to play its own tune.

“What always strikes me is the sheer abundance and diversity of life in an area so small,” says Dr Robert Bullock. “That alone is one of the most important factors for defining this place as special.” As the research director at the Save Our Seas Foundation D’Arros Research Centre (SOSF-DRC), Robert tries to understand what sets this site apart – and what we stand to lose if we don’t protect it. He is part of a team that implements conservation-oriented research and monitoring on the island. It is a mandate handed down when the Save Our Seas Foundation (SOSF) assumed stewardship of the island in 2012 and shaped the vision of the SOSF-DRC, formed under the island’s private ownership in 2004.

D’Arros Island is small. So small that you could stroll around its oval perimeter in less than two hours. Neighbouring St Joseph Atoll is a ring of 16 islands on a shallow reef flat that surrounds a 3.5-kilometre-long lagoon. “There are many places in the world where you can enjoy a day’s incredible diving, but you return the following day to nothing,” says Dr James Lea, the CEO of the SOSF and a marine biologist who has spent countless hours tracking sharks here. “It’s unpredictable. It’s patchy. D’Arros and St Joseph are remarkable for their density and consistency of life.”

The rich biodiversity is underscored by an array of habitats that create a variety of living conditions. “There is seagrass habitat, lagoon habitat, shallow coral reef habitat, deep pelagic habitat – all right on top of each other,” says James. D’Arros and St Joseph are separated by a channel one kilometre wide and 70 metres deep. This natural divide notwithstanding, they are considered one ecological unit. St Joseph is one of only six atolls in the Seychelles and the only one to be considered fully enclosed. “There are reefs on the northern side of D’Arros where the crest slopes down steeply to about 20 metres and then goes onto the Amirantes Bank. The upwelling pattern here is different from the one to the south, with its more gradual slope,” says Robert as he sketches out the undersea landscape with his hands, spreading them wide as he explains. “We’re sitting on the Amirantes Bank, which is this huge space of shallow water with expanses of sea grass to the north and south, which are in themselves massive ecosystems connected to everything here. We’ve got dolphins and whales offshore that are almost certainly bringing nutrients to this system through their faeces. As are the sharks, turtles and seabirds. They all live in different habitats, but carry important resources as they move around.”