The term "mattanza" (the slaughter) come from the Spanish word "matar", meaning to kill and refers to a hundred years old tuna-fishing tecnique. Tuna are guided into the "tonnara" which is a complex trap system of successive nets which are gradually restricted in size and raised toward the surface. Tha last is called "camera della morte" (the chamber of death). Here, when the "rais" (the head fisherman of mattanza) gives order and the "tonnarotti" haul the net, fishes come to the water surface and are hauled aboard boats with steel hooks. As time passes, the tunas are diminishing in size and number and this tradition is dying.
I took these photos on June 1980 on Ektachrome film.
Here the story: https://www.juzaphoto.com/article.php?l=it&t=mattanza_tonno&npost=&show=