Bluefin tuna's return to UK seas offers proof that nature can heal, says WWF

Bluefin tuna, the giant ocean predators that all but vanished from British waters decades ago, are now back in striking numbers around the UK coastline, according to a major new report from WWF. The conservation charity points to the species' dramatic comeback as evidence that determined action can repair damaged ecosystems — even as its flagship Living Planet Report 2026 warns that wildlife populations worldwide have crashed by an average of 73% since 1970.

The tuna's disappearance traces back to an era of industrial exploitation. Britain once supported large-scale tuna fisheries, but decades of overfishing — targeting not only the tuna themselves but also the smaller fish on which they feed — drove the animals out of UK seas. By the 1960s, the fishery had effectively collapsed, and for generations of British anglers and fishers the species became a memory rather than a fixture of coastal life.

What has changed, the report argues, is coordinated international management. Recovery has been credited to a sustained effort combining reduced catch quotas, minimum size limits and legal protection for spawning grounds, all supported by public pressure from consumers, chefs and retailers who demanded more responsible sourcing. Hannah Rudd, head of marine at the Angling Trust, described the outcome as close to an "explosion" in tuna numbers and called the species "a golden case study that fisheries management works".

The tuna story sits at the heart of a report that WWF is deliberately framing as a message of hope rather than despair. Mike Barrett, chief scientific adviser at WWF-UK, told the BBC simply that "it's not too late". He has worked on seven Living Planet reports, but said this was the first edition in which the central takeaway was to concentrate on what can still be achieved. "Hope is not the same thing as wishful thinking," Barrett explained, adding that hope "is not passive" but rooted in action.

WWF is calling this approach "the science of hope". Barrett said the successes it documents share common ingredients: a clear goal, a credible plan for reaching it, and a group of people who genuinely believe they can make a difference. The report compiles several such cases from around the world to illustrate the point.

Among them are wild tigers, whose numbers have risen by more than 70% — from roughly 3,200 in 2010 to about 5,700 in 2025 — helped by habitat restoration including work in Nepal's Khata Biological Corridor. The green sea turtle last year became the first marine turtle to be downgraded on the conservation scale from "endangered" to "least concern", a milestone reached after half a century of protection efforts spanning some 80 countries. In parts of southern Africa, elephant populations are stable or growing, a shift credited in part to legislation enabling local communities to share in the tourism income these animals generate.

Yet the report is unflinching about the wider picture, which it describes as nature being in "freefall". Working alongside the Zoological Society of London, WWF monitors nearly 36,000 populations across almost 6,000 species of mammals, birds, fish, reptiles and amphibians. From that dataset it estimates an average 73% decline in monitored wildlife populations over the past five decades.

It is important to understand what that headline figure does and does not represent. The index measures the average change in the size of tracked populations, not a raw tally of individual animals lost. And roughly half of the monitored populations are stable or increasing — but those gains are more than offset by steep declines elsewhere. The overall average remains firmly negative.

Experts also caution that the index offers only a partial view of the natural world. Dr Katie Collins, a senior curator at the Natural History Museum in London, noted that because it covers only vertebrates, it excludes plants, insects and the myriad organisms that underpin ecosystems. Her warning illustrated the interconnectedness at stake: "If you lose garden snails, you lose the song thrush," she said.

WWF stresses that conservation measures alone will not be enough to reverse the global decline. The underlying drivers must be confronted directly. Chief among them is farming, which can destroy the habitats wildlife depends on, and the burning of fossil fuels for energy, which accelerates climate change and reshapes the conditions in which species survive.

The charity also highlights a stark imbalance in global spending. In 2023, it estimates, roughly $7.3 trillion (£5.53 trillion) financed activities that damage nature, while just $220 billion went towards protecting or restoring it — a ratio of about 33 to one. In WWF's analysis, money is flowing in precisely the wrong direction.

Even so, the report's editors believe the window for action, though narrowing, remains open. Barrett described it as "extraordinary" that the science still points to a viable way out of the crisis. "So it's a closing window," he acknowledged, "but it is a window that is still open." For the bluefin tuna returning to Cornish waters, that argument has already been proved in practice.