Thunnus thynnus: The Atlantic Bluefin Tuna’s Return to UK Waters in 2025

Thunnus thynnus, known to anglers and scientists as the Atlantic Bluefin tuna, is surging back into UK waters with a vengeance, dazzling with dolphin-like leaps, a top speed of 43 mph, and sizes dwarfing polar bears. Once a ghost in these seas, Thunnus thynnus has seen sightings climb steadily in recent years, reigniting passion among the scientific community, recreational fishers, and commercial operators. Since 2021, the Catch and Release Tagging (CHART) programme has tracked Thunnus thynnus across English waters, while a small-scale commercial fishery probes its resilience. In 2025, from Cornwall’s rugged shores to the Celtic Deeps, Thunnus thynnus embodies a story of recovery—and a urgent call for sustainable management. Here’s how this legendary species is reshaping UK fishing today.

Thunnus thynnus Sightings in UK Waters

Thunnus thynnus was once a familiar sight across UK waters, from the North Sea to the Southwest, until overfishing drove it to near extinction here by the 1990s. In the 1930s, a world-renowned recreational fishery for Thunnus thynnus thrived, drawing aristocratic anglers to Scarborough and Whitby—until stocks crashed in the 1950s. For decades, this mighty fish was a memory, but the 2010s brought a shift. Thanks to stricter quotas from the International Commission for the Conservation of Atlantic Tunas (ICCAT) and warming seas shifting prey like mackerel and herring, Thunnus thynnus sightings began ticking upward. By 2025, Atlantic Bluefin tuna are regulars off Cornwall, Devon, the Isles of Scilly, and even parts of Wales—a resurgence that’s turning heads and filling logbooks.

Tracking Thunnus thynnus: CHART and Beyond

The return of Thunnus thynnus demanded action, and in 2021, the CHART programme launched in English waters, a collaboration between anglers and experts from Cefas, the MMO, and Bluefin Tuna UK. Funded by Defra, CHART grew by 2022 to 25 charter boats operating mid-August to mid-December, tagging over 1,700 Thunnus thynnus across 1,052 dedicated trips with more than 2,800 anglers. The 2023 season (14 August–10 December) wrapped with critical data, setting the stage for 2025’s CRRF (180 permits) and a 45-tonne commercial quota for 15 boats. But a Farming Today remark in 2023 from Minister Mark Spencer—pushing Thunnus thynnus as a fallback amid pollack bans—hints at rising pressure on this recovering species.

Biology of Thunnus thynnus

What sets Thunnus thynnus apart?

  • Size: The largest tuna species—200-250 lbs average in UK waters, up to 1,000 lbs locally, with a 1,496-lb world record (see size post (#)).

  • Speed: Built like torpedoes with retractable fins and keen vision, Thunnus thynnus clocks 43 mph, chasing herring, squid, and eels (lure guide (#)).

  • Lifespan: Living up to 40 years, they grow 30 cm/year as juveniles, slowing with age (FishBase).

  • Adaptation: A countercurrent exchanger keeps Thunnus thynnus warmer than surrounding waters, powering dives past 3,000 ft and hunts in cold seas.

  • Range: From Labrador to Brazil and Norway to the Mediterranean, Thunnus thynnus migrates vast distances—yet its return to UK waters marks a rare homecoming for this oceanic predator.

Thunnus thynnus in UK History

Thunnus thynnus has deep roots in UK fishing lore. In the early 20th century, the North Sea was a global hotspot for Atlantic Bluefin tuna, with Thunnus thynnus drawing elite anglers to Yorkshire’s coast. Scarborough’s fishery peaked in the 1930s, boasting catches of 500-800-lb fish—some rivaling today’s biggest Bluefin tuna in UK waters. But by the 1950s, relentless fishing collapsed this bounty, and Thunnus thynnus faded from UK shores. The 1990s saw near-total silence—no sightings, no hope—until ICCAT’s 2007 recovery plan turned the tide. Today, Thunnus thynnus is rewriting its UK story, with 2025 poised to test whether history repeats or redeems itself.

Conservation and Fishing Challenges

The Thunnus thynnus comeback is a victory—lifted from Endangered to Least Concern on the IUCN Red List in 2021—thanks to ICCAT’s efforts. Yet, the road ahead is rocky. Overfishing gutted Thunnus thynnus stocks once; now, 2025’s commercial trials (rod-and-line only) aim for balance, but scaling up could unravel this progress. Recreational anglers face their own test—landing 200-500-lb Thunnus thynnus demands 50-80-lb rods and reels (rod post (#), reel post (#)) and stand-up techniques (stand-up guide (#)) to keep fights short (30-90 minutes) and fish healthy. Groups like The Wildlife Trusts urge sustainable choices—eating responsibly and supporting marine recovery—to ensure Thunnus thynnus remains a UK fixture, not a fleeting guest.

Join the Thunnus thynnus Journey

Thunnus thynnus is back in UK waters for 2025—a triumph of nature and a challenge to protect. Gear up with our tackle guides at ukbfta.co.uk or atlanticbluefintuna.co.uk. Caught a Thunnus thynnus or want to safeguard its future? Share below or tag #AtlanticBluefinTuna on X. Tight lines—let’s keep the Thunnus thynnus legacy alive!