The mattanza (from the Spanish word matar, meaning to kill) is a complex and ritual way of catching tuna fish which characterized the island of Favignana every year at the end of May. The tuna fishing has very ancient origin, possibly even to the Phoenicians, but it was under the Arabian domination that the most fundamental elements of this "rite" were firmly established. The fishermen of tune (also called tonnaroti) make the same gestures, pronounce the same prayers, sing the same "cialome" (ritual sings) for many centuries.
Times and practices are fixed by the rais, the chief of the tuna station, who is magician, saint and sorcerer at the same time. Gioacchino Cataldo, also known as Poseidon, is the actual rais of the tuna station of Favignana, listed in the Intangible Cultural Heritage: he is a living treasure which can transmit to the future generations oral traditions, expressions and ancient rituals.
The fishing boats put out to sea to lay the nets in a long corridor which the tuna are forced to follow. The last nets are dropped like barriers to form antechambers that will prevent too many fish from being gathered in a single unit, thus averting the risk of the nets being torn and the fish escaping. Beyond these antechambers is laid the "camera della morte" (the room of the death), an enclosure provided by tougher netting and often closed along the bottom. When an appropriate number of fish are deemed to be trapped in the chamber, the rais orders to begin the mattanza.