On a visit to Libya in 2005, I met some Italians who had come to a coastal town to teach the Libyans how to farm fish. With hundreds of miles of Mediterranean coastline, North Africa has long been the site of fishing, fish farming, and many other marine activities. Against this backdrop comes news of an exciting find of a submerged city, Neapolis, off the northeastern coast of Tunisia, made by a joint underwater team from the National Heritage Institute of Tunisia and the University of Sassari, in Italy. Among the finds at Neapolis were more than 100 tanks for salting fish and making garum, the celebrated fish sauce that was a key ingredient in Roman cookery.
In antiquity the Mediterranean coastline was littered with similar factories, but this discovery provides further evidence of how the Romans exploited marine resources. From fish farming to fish salting, and from garum making to purple-dye extraction (from murex shells also found on the North African coast), the Romans practiced aquaculture on an industrial scale. Andrew I. Wilson, of the Oxford Roman Economy Project, and Annalisa Marzano, of the University of Reading, have done much in recent years to teach us how the Romans harvested the bounty of the seas. A fish-salting factory with especially well-preserved tanks can be easily visited in Barcelona beneath the Museum of History (see photo).
Finally, a word about garum: contrary to popular opinion, garum was not a sauce of rotten fish made to mask even more rotten meat and other perishables. Rather, it was the fermented liquid byproduct of salted fish, similar to the Vietnamese fish sauce nuoc mam and embodying the same flavor principle, umami, savoriness. It could be made from various types of fish and fish parts, from tuna, mackerel, and mullet to sardines and anchovies. Given this variety, garum could not have been made according to a single recipe; indeed, it seems likely that the most successful producers added their own secret ingredients (possibly there were even garum “vintages”). How else can we explain how the Pompeian producer Umbricius Scaurus made a fortune with his fish sauce?
Mosaics decorating Scaurus’ home at Pompeii depict typical fish sauce jugs labelled liquamen, another kind of ancient fish sauce. Recently Sally Grainger, a chef-turned-experimental archaeologist, whose dissertation involved reproducing the fish sauces described by ancient authors, has argued that it is incorrect to name all fish sauces garum. Rather, she says, the term refers specifically to a sauce made from fish blood and viscera, while liquamen specifies sauce made from whole fish. Both were available in many grades and found different uses in the kitchen.
Steven Ellis, of the University of Cincinnati, has excavated a small mom-and-pop garum workshop in Pompeii that may have been put out of business by cheap imports from ancient Baetica, in what is now southern Spain—obviously globalization is not an exclusively modern concern. The discarded potsherds that form the Testaccio mountain in Rome—most with olive-oil residues but some with traces of fish—are largely from Baetica, confirming massive Spanish food imports into Italy in the imperial period.
Together, archaeological artifacts like garum vats and pottery underscore the important point that in a preindustrial society like ancient Rome, almost all the economic output was related to food production.