Tagging the Cornish tunny

Enormous Atlantic bluefin tuna are once again making waves in UK waters almost a century after their showstopping appearance in the North Sea

- Neil Cross

NINETY-ONE years ago, the British Tunny Club was established to facilitate the competitive sport-fishing of Atlantic bluefin tuna in the North Sea. Each year aristocrats, movie moguls and moneyed sportsmen would descend on Scarborough and Whitby in North Yorkshire in their motor yachts to do battle with Thunnus thynnus from open rowing boats, piloted by local oarsmen.

The photographs that survive from this period show determined chaps in stiff collars and hairy tweeds beside bluefins weighing more than 700 pounds on the gantry. This sport ended shortly after the Second World War when the overfishing of herring stocks by industrial trawlers effectively called time on the annual migration of large tunny into British waters.

By the 1990s, a bluefin sighting had become a rare event in the UK, with only the occasional fish making the news. However, all this began to change during the past decade, and fishermen in the English Channel started to see more and more bluefin popping up and sometimes coming aboard as by-catch in their nets. By 2018, this resurgence had attracted the attention of marine biologists and academic institutions who were keen to know if this was, indeed, a new era of established migration or simply an aberration caused by warmer seas and a changing climate. In April of that year, Thunnus UK was launched. This formed part of a collaborative research scheme, supported by a range of bodies, including Defra; the Centre for Environment, Fisheries and Aquaculture Science; the European Maritime and Fisheries Fund; and the universities of Exeter, Plymouth and Stanford, in the USA. The scheme informs the wider work of FISHINTEL, which has established a network of acoustic receivers on both sides of the Channel to track the progress and movements of tagged fish.