The most remote inhabited island is racing to protect its seas – and only source of income.

The fishing gong is calling. At 05:00 local time, the clang of a hammer on an old oxygen gas cylinder wakes me up. It's fishing day on Tristan da Cunha, a speck of land in the South Atlantic Ocean that is home to barely more than 200 people. Beyond the UK Overseas Territory, the nearest inhabited settlement lies more than 2,400km (1,491 miles) away.

As the gong fades, dogs bark, engines rev, and the scrape of rubber boots echoes through the air as fishermen head to Callshot Harbor, nicknamed "the Beach", to bait their traps and ready their boats. With just 18 to 72 fishing days per season, every opportunity counts.

They're after Tristan's most valuable commodity: the St Paul spiny lobster (Jasus paulensis), found only near remote islands in the world's southern oceans. Prized for their sweet, delicate meat, a single tail can fetch $39 (£29) on the US market. The lobsters are also sold in Japan and the UK. Here in the cool, temperate waters of the Tristan da Cunha archipelago, the crustaceans thrive close to shore, at depths of up to 200m (656 ft).

But Tristan has not always been able to depend on its lobster bounty. Decades ago, heavy fishing caused a significant reduction in lobster numbers here. Today, Tristanians depend on the catch – but they also know that, without proper protections, the lobsters are at risk.

"We have always relied on the ocean as a source of food, managing it to the best of our abilities. Which means not taking more than you need," says James Glass, head of Tristan da Cunha's Department of Fisheries. "This is a precious place, and we want it to stay that way."

"It's our livelihood. Without the ocean, our community wouldn't function," says fisherman Shane Green.

Now, as the world's oceans face mounting pressures, and climate change, invasive species and illegal industrial fishing threaten both the marine ecosystem and the island's main source of income, the people of Tristan da Cunha are determined to ensure the spiny lobsters', and their own, long-term survival.

The island's fishermen work in the middle of the world's fifth-largest marine protected zone (MPZ) which covers an area of 687,000 sq km (265,252 sq miles). In 91% of Tristan's territorial waters, commercial fishing is entirely banned. In the remaining zones, strict quotas, size limits, and onboard monitoring apply, with satellite surveillance helping to detect and deter illegal activity.

Jason Green and his fishing partner, Dean Repetto, have sailed together for a decade. Like most Tristanians, their ancestral connection to the sea dates back more than a century.

"Fishing has been passed down through my family for generations," says Repetto, who also works as a mechanic for Tristan's Department of Fisheries.

On a fine day in January 2024, Dean, Jason and their apprentice Tristan Glass, head out to sea in Island Pride, their 8m (27ft) bright-orange boat. Leaving Tristan's tiny harbour, they head east, weaving through offshore forests of giant kelp, towering brown algae that can grow over half a metre per day and reach 45m (150ft) in length.

They're headed to their mark, a fishing spot on the southern side of the island that fishermen here can identify through triangulation of landmarks and the depth of the ocean at certain locations.

"It could be a pinnacle, it could be like a gulch, it could be a hut or a hill, and you line one up with the other one," says Eugene Repetto, who fishes on the Kingfisher.

On the Island Pride, the apprentice Glass' face growing pale – the hallmark of seasickness. It's an especially tough job for some.

As Glass sleeps off his symptoms, Green drops 16 large traps in deep water. He will leave them for hours – long enough for lobsters to find the bait. Then, Repetto steers for shallower water, where Green lowers hoop nets with which to snare lobsters in the underwater kelp forests. They haul these nets aboard every hour. Before heading back to harbour, they will retrieve their catch from the deeper traps set earlier.

Omnivorous and clawless, Tristan's lobsters use their long antennae to navigate the rocky seabed, feeding at night on sea urchins, molluscs, and other kelp-consuming invertebrates. This helps to sustain the underwater forests that shelter many other marine species. Spiny lobsters are a vital link in the food web, scavenging dead animals and organic matter, recycling nutrients, and serving as prey for predators including octopus.

The people of Tristan da Cunha, all 229 of them, live in extreme isolation, surrounded by millions of square kilometres of open ocean. Their closest inhabited neighbour, St Helena – where Napoleon lived out the last of his days – lies 2,414 km (1,500 miles) to the north. Montevideo, Uruguay, is 4,023 km (2,500 miles) west. To the south, only a scattering of uninhabited islands separates Tristan from the icy wilderness of Antarctica.

The only regularly used route to Tristan – from Cape Town, South Africa – is unreliable. Securing one of just 136 berths on one of nine annual ships is only the start. The 2,819 km (1,752 mile) journey can take up to two weeks, depending on the weather.

I spent 10 months on Tristan with the photographer Julia Gunther, from December 2023 to October 2024. When we........

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