Bluefin tuna routes: 13 years of sea heat clues

Thirteen years of sea temperature data offer a new clue to where bluefin tuna may travel through the Strait of Gibraltar, between the Atlantic and the Mediterranean. The Spanish Institute of Oceanography reported the findings on 5 November 2026. The study, published in Fisheries Oceanography, involved the Mediterranean Institute for Advanced Studies and a researcher from the Balearic Oceanographic Centre.

Tags and satellites track the temperatures

Researchers compared readings from electronic tags fitted to bluefin tuna with satellite measurements of sea surface temperature. They focused on the Strait of Gibraltar and the Gulf of Cádiz. When the tagged fish entered the Mediterranean, surface temperatures ranged from 17.4 to 19.3°C. On their way back towards the Atlantic, the range was 18.4 to 22°C.

What the findings could change

The team used those readings to create an index showing where and when sea temperatures match conditions recorded during the migrations. Applied to 13 years of data, it showed how suitable areas varied along the tuna’s routes.

Lead author Enrique Sánchez-Fabrés, of the Balearic Oceanographic Centre, said understanding the effect of environmental conditions matters for bluefin tuna conservation and fisheries management. Those conditions may also affect how easily the fish are caught, including by traditional fishing methods such as almadrabas.

Topics: Nature & wildlife

Source: Europa Press / Mallorca.com