Bluefin tuna flood back to British seas in sign conservation can work, says WWF

Giant bluefin tuna are returning to waters around the UK in numbers not seen for decades, according to a major new report from WWF that argues the recovery of the predatory fish is proof that nature can bounce back when people choose to act. The charity's Living Planet Report 2026 highlights the tuna's comeback off Cornwall and elsewhere as one of several wildlife success stories, even as it warns that monitored animal populations around the globe have declined by an average of 73% since 1970.

The UK was once home to thriving tuna fisheries, but decades of overfishing — of the tuna themselves and of the smaller species they feed on — drove the fish out of British waters. By the 1960s, the population had largely vanished from around these shores. Its gradual return has been credited to a sustained international effort that combined reduced catch quotas, minimum size limits and the protection of spawning grounds, alongside pressure from consumers, chefs and retailers who pushed the industry to change course.

Hannah Rudd, head of marine at the Angling Trust, described the outcome of that coordinated campaign as close to an "explosion" in tuna numbers. She pointed to bluefin as what she called a golden case study, demonstrating that fisheries management — when it is properly enforced and internationally agreed — actually delivers results. The species' trajectory, she suggested, offers a template for rebuilding other depleted stocks that have been written off as beyond rescue.

Mike Barrett, chief scientific adviser at WWF-UK, told the BBC that the report's central message is deliberately one of optimism rather than despair. "It's not too late," he said, arguing that the successes catalogued in the study all shared the same ingredients: a clear goal, a credible plan, and a group of people who genuinely believed they could make a difference. WWF has labelled this approach "the science of hope".

Barrett was careful to distinguish that optimism from complacency. "Hope is not the same thing as wishful thinking," he said. "Hope is not passive. Hope's about action." Having worked on seven Living Planet reports, he said this was the first occasion on which the takeaway message was to focus on hope — a shift he described as extraordinary, given how much ground has been lost.

The tuna is far from the only species cited as a turnaround story. The report records an increase of more than 70% in wild tiger numbers, rising from roughly 3,200 animals in 2010 to about 5,700 in 2025, helped by habitat restoration in places such as the Khata Biological Corridor in Nepal. Last year, the green sea turtle became the first marine turtle to have its conservation status downgraded from "endangered" to "least concern", a milestone reached after half a century of protection work spanning some 80 countries.

Elephant numbers, meanwhile, are stable or increasing across parts of southern Africa. A contributing factor, the report notes, is new legislation that allows local communities to keep a share of the income elephants generate, including revenue from tourism — an approach designed to give people a direct stake in keeping the animals alive rather than viewing them as a liability.

Yet for every bright spot, the overall picture remains bleak. Working with the Zoological Society of London, WWF monitors close to 36,000 populations spanning almost 6,000 species of mammals, birds, fish, reptiles and amphibians. On the basis of that dataset, it estimates that monitored wildlife populations have fallen by an average of 73% over the past five decades, prompting the charity to describe the state of nature as "freefall".

The report is careful about what that statistic does and does not mean. The 73% figure measures the average change in the size of tracked populations, not a headcount of individual animals lost. What is more, around half of the monitored populations are stable or increasing — but those gains are outweighed by steep declines elsewhere, underlining how unevenly the biodiversity crisis is distributed.

There are also significant gaps in what the index can tell us. Dr Katie Collins, a senior curator at the Natural History Museum in London, noted that the measure covers only vertebrates, excluding plants, insects and the countless other organisms on which those animals rely. Losing the creatures at the bottom of the food chain, she warned, eventually removes those at the top — "If you lose garden snails, you lose the song thrush," she said.

WWF stresses that conservation on its own cannot reverse the damage; governments and businesses must also confront the underlying drivers. The two greatest pressures, it says, are farming, which can destroy the habitats wildlife needs to survive, and the burning of fossil fuels for energy, which accelerates climate change and reshapes the conditions in which species can live.

The charity also argues that global finance is pointed in the wrong direction. In 2023, an estimated $7.3 trillion (£5.53tn) was spent on activities that harm nature, against just $220bn invested in protecting or restoring it — a ratio of roughly 33 to one. Closing that gap, WWF implies, is as much a political choice as an ecological one.

For all the warnings, the report's authors insist the evidence shows decline is not inevitable. Recovery is possible, they argue, when targets are specific, strategies are rooted in science and communities are empowered to participate — and the window for doing so is narrowing. "The fact that the science is still telling us that we've got a way out is actually extraordinary," Barrett said. "So it's a closing window."