Eaten fresh or preserved, the albacore tuna and blue-fin tuna have always been highly prized by the Basque people and linked to fishing since time immemorial.

The albacore or white tuna (thunnus alalunga) and the blue-fin or red tuna (thunnus thynnus) are two of the best established fish in the north of the peninsula and particularly in the Basque Country. The albacore tuna has whiter flesh than the blue-fin, which means it is the more highly prized of the two. The Kalitatea foundation grants a label to albacore and blue-fin tuna in the "A" and "Extra" categories of freshness only to fish caught by traditional methods respectful of the marine environment. The fish can be recognised because it has a white security tape on its tail, on which the following information appears: the name of the port where it has been unloaded and checked; the name of the species; a control number that identifies the boat which caught it, the unloading date, the checking team that selected it and the symbol of Eusko Label-Kalitatea, guaranteeing its quality.