DNA from cetariae fish remains confirms sardine (Sardina pilchardus) use and local population continuity in Northwestern Iberia since Roman times

The Romans were one of the first societies to fully explore fish resources, creating large scale salting and preservation plants to prepare fish for storage and transportation across the empire. Small pelagic fish were used to make fish sauces, like garum. Here, for the first time, we recover DNA from 18 specimens retrieved from the bottom of fish salting vats from Adro Vello, Galicia radiocarbon dated to the 1st to 4th centrury AD. Using whole genome resequencing on 17 specimens, we reconstruct the mitogenomes and identify which species they belong to through phylogenetic analysis. Exploring this, so far overlooked, archaeological material, either due to its fragmentary nature or difficult identification, will open a new window into the past for the understanding of subsistence economy, culture, and the diet of past peoples.