Fish-salting Production in Northwest Iberia: A Multidisciplinary Approach at the Site of Ferrazo (Northwest Iberia)

Ferrazo (Vilagarcía de Arousa, Pontevedra, Spain) – in the northwest of the Iberian Peninsula – is a complex Roman site originally located on the seashore including a cetaria (fish-salting factory). The extremely good preservation of this site offered the possibility of enlarging our current knowledge about fish-salting production in northwest Iberia, where these productive sites dedicated to marine resource exploitation were frequently established along the coastal areas during the Roman Period. We present the archaeological excavation record and the results of a multidisciplinary analysis after systematic sampling of a salting vat content. Our multidisciplinary approach combines ichthyofaunal studies, scanning electron microscopy Energy Dispersive X-Ray Spectroscopy (SEM-EDX), conventional analytical pyrolysis (Py-GC-MS), thermally assisted hydrolysis and methylation (THM-GC-MS), archaeobotanical analysis, and AMS radiocarbon dating. Sardina pilchardus is the almost exclusive fish species preserved within the vat involved in fish-salting, which were processed entirely, in accordance with ichthyofaunal remains and chemical markers. The presence of fragments of charred wood might be related to the addition of wood ash during the production process.