Tristan da Cunha: 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.

According to BBC, 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. “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.

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’s 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 first arrived, heavy swells closed the harbour, forcing us to wait five days aboard a ship offshore before we could finally land.

The island’s only settlement, Edinburgh of the Seven Seas, has no airport, hotels, or restaurants. What it does have in abundance are towering cliffs, a strong sense of community and a vast expanse of pristine ocean. Isolation, and strong survival instincts, have shaped every aspect of life here. Commercial fishing arrived on Tristan during the 1940s and, since then, lobster has been the cornerstone of the island’s economy. Spiny lobsters even feature in Tristan’s coat of arms.

While there is no conclusive evidence yet – largely due to the limited number of studies – there are signs that climate change could have serious consequences for Tristan’s marine environment. One study shows that rising sea temperatures are already affecting the summer growth of kelp – a crucial habitat for lobsters – and that warming seas could also push lobsters further south, beyond the island’s reach. Cheseldon Lavarello, now 82, tells me of the enormous catches he helped bring ashore when he first went to sea aged 15: “My fishing partner and I could catch 1,360kg (3,000lb) in a day using just 10 nets.”

In the early days, the fishery was barely regulated, James Glass recalls. Undersized lobsters and egg-bearing females were often taken before they had a chance to reproduce. It wasn’t until 1983 that the Island Council brought in size limits. A quota followed in 1991- though, according to James Glass, neither was strictly enforced until 1997. In March 2011, the MS Oliva ran aground on Nightingale Island, spilling 65,000 tonnes of soybeans and fuel. Thousands of northern rockhopper penguins and other seabirds died. The fishery at Nightingale and Inaccessible Islands closed temporarily.

Despite events like this, scientific expeditions, including National Geographic’s Pristine Seas in 2017, led by Paul Rose, found an abundance of wildlife seemingly unperturbed by commercial fishing or past ecological disasters. Rose and his team conducted the first in-depth survey of the island’s marine life, using scuba dives, deep-sea cameras and satellite tagging. It confirmed what many islanders already knew: Tristan’s seas are among the most pristine on Earth, home to globally significant seabird colonies, shark nurseries and vast kelp forests.

The environmental incidents and survey data together also raised a deeper question around how Tristan might protect its waters for the future without sacrificing its all-important fishery. The idea of a total fishing ban, for instance, was anathema. The entire community here depends on the catch for survival, and a ban would not stop future disasters or near misses, most of which have been caused by transiting vessels, not fishing. And what if outside entities, including the UK Government, imposed a marine protected zone that ignored local needs?

“Tristan had a unique opportunity to take the lead in the creation of its marine protected zone,” says Andy Schofield, who leads the overseas territories work for the Royal Society for the Protection of Birds, a UK wildlife conservation non-profit. Between 2017 and 2019, Tristan’s government, the Island Council, fishery operators, and conservation scientists worked out a plan. “We needed to tell [the UK], This is what Tristan wants,” says Schofield.

The final design, adopted in 2019, drew heavily on local knowledge. The MPZ covered 687,000 sq km (265,252 sq miles), with 91% of Tristan da Cunha’s Exclusive Economic Zone (EEZ) closed entirely to fishing. Crucially, it allowed for a designated inshore fishing zone for the commercial lobster fishery, preserving the island’s economic lifeline. The plan also created “Areas to Be Avoided” (ATBAs) for shipping, reducing the risk of accidents near sensitive habitats.

“Local and global economies go hand-in-hand with MPZs,” says Rose. “More protection equals more fish.” Tristan also began sending representatives abroad. “Our waters are a safe haven for wildlife,” says Janine Lavarello, Tristan da Cunha’s marine protection zone officer. “We want people to understand that if our small community can set up this huge marine protection zone, imagine what bigger countries can achieve.”

Identifying and designating marine protected areas, however, is comparatively easy to policing and enforcing them. Tristan is the only UK Overseas Territory without its own dedicated vessel or airport. Instead, it relies on satellite tracking and global networks to police nearly 700,000 sq km (270,270 sq miles) of ocean. “You can’t protect what you can’t see. Satellite monitoring fills that visibility gap, playing a pivotal role in… safeguarding remote marine ecosystems,” says Monica Esponiza Miralles, head of Latin America for Global Fishing Watch, an international non-profit.

The UK’s Marine Management Organisation supports Tristan’s MPZ by interpreting data from Automatic Identification Systems to flag vessels behaving suspiciously, such as slowing or drifting in