Fish in the Roman World

During the days of the Roman Republic and Empire, direct human interactions with marine ecosystems around the Mediterranean usually consisted of fishing, pisciculture, and fish processing (including fish salting and the making of fish sauces). Research during the past few decades has shown that both fresh and preserved fish and shellfish were integral to the diet, culture, and economy of people living in both the Roman Republic and the Roman Empire. Especially in coastal areas, the Romans regularly fished, bred, salted, and processed marine organisms on a daily basis.

Some fishes, especially marine ones, were considered luxury items. Others, such as abundant gregarious fish (e.g., mackerel, sardines, anchovies, tuna), were easily caught as fishermen kept track of their migration patterns and caught them mid-route. Small gregarious fish usually had a lower commercial and social value than large marine fish, just as salted fish had a lower commercial and social value than fresh fish, but they were an important source of protein for the majority of the coastal population because they were much more affordable.

Fishing methods employed by the Romans were similar to those used by the Greeks, and indeed similar to the methods employed by people around the Mediterranean today. Different fishing implements were used for different fish in different environments. Basic implements included the hook and line, seine, casting-nets, and traps. Individual fishermen usually employed traps or a hook and line, since these required minimal manpower and investment. But when it came to catching gregarious fish in high demand, the Romans wanted large catches which required significant investments in terms of manpower, time, and money. In response, fishermen’s guilds were formed, where individual fishermen pooled their resources together to buy equipment and lower risk, thus creating a basic business model for commercial fishing. In such cases, as many as seventy persons may be involved, and they would use weighted casting-nets, which usually promised big catches with little resource input. Another option was to fish with large seines or fixed nets; though they were time-consuming and required teams of fishermen to cast and pull the nets, they also promised large catches.

After a catch, the Romans needed to find ways to prevent the fish from spoiling. The most basic and direct way to accomplish this was to quickly transport fish in carts and wagons to the market. Fish transported by land, however, lost commercial value quickly; if they were not sold out in hours, they would be too spoiled to eat. This also meant that fresh fish was only available to the coastal population. Anyone living inland would be out of luck—except, of course, for the wealthy, who could afford to import marine fish in ship-vivaria.

A vivarium is a facility used for live storage and/or breeding and fattening of fish, a practice known as pisciculture or fish farming. Ship-vivaria, however, were not used for fish farming but for transportation. In basic terms, a ship-vivarium is a water-filled tank built into a ship, used to bring fresh marine fish inland by river. Ship-vivaria began to be documented in the first century AD, but so far archaeological evidence has been scarce, suggesting that their use was limited, especially since only a wealthy minority could afford it.

But for upper-class Romans, fresh fish could always be had at their private vivaria. Such vivaria may refer to enclosures in muddy and sandy-bottomed areas that hold fish in their natural habitat, or it may refer to piscinae, a series of large interconnected tanks, often belonging to upper-class Romans and incorporated into the architecture of their coastal villas. Driven by a desire for fresh fish beyond the small tanks of ship-vivaria, wealthy Romans built piscinae to be free-standing on the coast but connected to the sea via channels. The artificially regulated environment of piscinae was designed to be less salty than the open sea in order to attract prized fish such as bream, mullet, and sea bass, and the channels were designed to refresh the piscinae’s water during high tides. Salinity and oxygen levels were carefully maintained in order to keep a fresh supply of marine fish all year round for the banquets of the rich.

Wealthy Romans with business acumen would even expand their piscinae to breed popular species on a large scale and earn a profit. For instance, a family-owned fish farm in Etruria covered almost two acres and produced an average of 150,000 kg of fish per year. Commercial pisciculture soon extended to oysters. The Romans built oyster farms where young oysters were harvested from the sea, strung up on ropes, and allowed to breed in a controlled environment. Oyster farms using this “hanging culture method” were commercially successful, producing species that were widely sought-after during this time.

For the middle and lower classes, however, a much more financially viable option was to consume fish sauce, a preserved fish product made from heavily salted and fermented fish. Beginning in the Iberian peninsula, the practice of eating fish sauce spread like wildfire through the Roman world. Two major factors accounted for its popularity: the ease with which it was transported and its availability in both cheap and expensive varieties. Ease of transportation extended the geographical area of fish consumption from just the coastal population to virtually the entire Roman empire and allowed this vast population to consume fish not only during certain seasons but all year round. The different varieties of fish sauce meant that every segment of the population could consume some form of preserved fish, be it the “cream” at the top of the sauce or the less expensive paste at the bottom.

Fish sauces were bottled in amphorae (vase-like containers used for carrying liquids), which were then loaded onto ships. Over the years, archaeologists have identified many amphorae with fish sauce remains as well as amphorae with inscriptions that note them as fish sauce containers. According to documentation of amphorae remains, fish sauce was so popular that one liter of one variety of fish sauce, garum, was consumed for every three liters of olive oil. Considering the extensive use of olive oil in the Roman world, not only in the kitchen but also in various other parts of the household, the amount of garum is by no means insignificant.

Widespread fish sauce consumption, which emphasized the salty taste of the sauce over the original taste of the fish, impacted fishing around the Mediterranean by shifting the focus from fishing for a specifically desired species to fishing on a massive, almost industrial scale for any species, in order to feed the activities of fish-salting plants. These plants (cetariae) were abundant on the Iberian Peninsula and the North African coast, each containing deep masonry vats where huge quantities of fish were salted and processed.

This endless demand led naturally to concerns about overfishing. Generally speaking, fishing in the Mediterranean remained at a sustainable level, and cases of overfishing were mostly localized. For instance, overfishing was noticed and dealt with in Corsica. For centuries people have used the technique of torch fishing—holding a torch on a boat at night to attract fish and cephalopods—and it was so effective at rounding up large catches that local authorities outlawed the practice in Corsica in the second century AD.