Disappearing Mediterranean tuna
Rising Mediterranean temperatures could, within about fifty years, force bluefin tuna to shift their spawning grounds northward to cooler waters, such as the Bay of Biscay
Andrew Linn
Friday, 12 December 2025, 11:19
At the height of the tuna season, the almadrabas are set off the Tarifa and Cadiz coasts. These funnel-shaped mazes of fixed nets trap migrating tuna as they pass through the Strait. Bluefin tuna continues to be revered as 'red gold'. Its richly flavoured flesh makes it one of the most sought-after species in gastronomy and its capture through the ancient almadraba has been practised for some 3,000 years.
A recent study by the University of Southampton, in collaboration with AZTI and the British Antarctic Survey, warns that this heritage may be threatened by climate change. Rising Mediterranean temperatures could, within about fifty years, force bluefin tuna to shift their spawning grounds northward to cooler waters, such as the Bay of Biscay. Juvenile tuna struggle when water temperatures exceed 28 °C, a threshold that climate models suggest the Mediterranean will increasingly surpass.
Wine of the week
-
Rias Baixas Marco Real 2021A special edition white wine made from 100% Albariño, aged on its lees for six months, created for one of Spain's most renowned chefs, Martín Berasategui. Originally intended exclusively for his restaurants, it is now available in leading wine shops and restaurants. About 14 euros.
Every year these bluefin migrate from the cold North Atlantic into the warmer Mediterranean to spawn near Sicily and the Balearics. Their passage through the Strait of Gibraltar allows the four Cadiz almadrabas to fish them for about two to three months annually. Should the tuna begin breeding in colder northern waters instead, they might bypass the Strait altogether, jeopardising a millennia-old way of life.
The almadraba remains vital to the local economy, providing about 500 direct and some 6,000 indirect jobs. Meanwhile, bluefin has become a centrepiece of Cadiz's cuisine, with chefs refining and reinventing its many cuts. If future migrations shift away from southern Spain, both this culinary identity and the traditional communities built around the almadraba could face profound change.
