The market(s) for fish in the city of Rome

There was a demand for fresh fish in the urban center of Rome from at least the mid-Republic, and literary evidence suggests that fish could be purchased in not only purpose-built retail settings but also more casual venues, like temporary stalls, or even on the street.Footnote ⁶ The Forum Piscarium, an early fish market near the Forum Romanum, was destroyed in the great fire of 210 BCE that claimed many structures in the vicinity.Footnote ⁷ The market was rebuilt at least twice; it was expanded in 179 BCE, and although Livy refers to the new structure as a Forum Piscatorium, it seems to have been converted into a proper macellum and offered other foodstuffs as well.Footnote ⁸ Varro writes that “along the Tiber at [the temple] they call it the Forum Piscarium,”Footnote ⁹ and suggests that this is the same fish market that Plautus refers to in Curculio.Footnote ¹⁰ Robert Palmer puts the Forum Piscarium along the Tiber just outside the Porta Trigemina and regards it as a second fish market, distinct from the Forum Piscatorium in the Forum Romanum.Footnote ¹¹ In a scene from Plautus’s Rudens, a character discussing the common right to things found in the sea notes that if one catches a fish, he owns it and can sell it “in the forum” without breaking any laws.Footnote ¹² This “forum” could refer to an imagined regional analogue of the Forum Piscarium, or, perhaps more likely, it could be a nod to more generalized ambulatory retail exchanges that occurred in or near the central forum or agora in any city’s urban core. The inscription for Aurelia the piscatrix (CIL VI 9801), for example, suggests that she plied her trade in the Horrea Galbae, a large warehouse and retail structure not far from the Emporium ports on the Tiber’s left bank – not a forum or market proper, but a multi-purpose building in a populous neighborhood well suited to retail activities. Claire Holleran takes the inward-facing units represented on the Severan marble plan as evidence that the Horrea Galbae could have functioned like a macellum, with customers entering the shops from the courtyards, or could alternatively have been a place where the piscatrix stored fishing equipment.Footnote ¹³ I find the former explanation more plausible given that Aurelia’s persona, as far as it is memorialized on the funerary monument, was apparently associated with her spot at the Horrea. We might even imagine that the Horrea Galbae hosted a wholesalers’ market out of which Aurelia supplied fishmongers throughout the city, thus accounting for her moderate financial success.

The degree to which fish products contributed to the ancient Roman diet is debated, and the proportion of fresh fish in any group’s regular dietary repertoire must have varied considerably. Archaeological evidence is uneven, but where fish remains have been collected and studied, it appears that fish was present in diets across social strata.Footnote ¹⁴ Salted and cured fish products (salsamenta) were popular modes of consuming fish protein throughout the ancient Mediterranean world. Perhaps closest to ubiquitous was the condiment garum, a sauce created by layering fish remains and salt and leaving the mixture to mature in the sun for a period of months. These preparations allowed marine fish like tuna, mackerel, and anchovies to be consumed much farther, in both time and space, from their places of origin.Footnote ¹⁵ Because they were transported in ceramic vessels, preserved fish products are more visible in the archaeological record than the more ephemeral remains of fish that were consumed fresh. But the wider market created by the production of salsamenta must have led to fresh fish being a particularly prized commodity throughout Roman antiquity.

One of the greatest challenges to selling fresh fish is getting it into the hands of consumers before it spoils. In the days before refrigeration, fish had an incredibly short shelf life, especially during the hot Roman summer. Fish hauled in from the sea or coastal estuaries would not have lasted for more than one or two days after being caught. The freshness of any such fish that were transported to the city of Rome would have been inversely proportional to the length of travel time. Fish transferred to a cart at Ostia and then transported by road to Rome would have arrived in about two days.Footnote ¹⁶ The trip by boat from the coast up the Tiber would have taken about three days with the efforts of towing crews of men (helciarii) or oxen hauling river boats upstream.Footnote ¹⁷ It is feasible that some fish were kept alive for these inland journeys. Boats fitted with water tanks could have alleviated some of the stress on captured fish and kept them alive for the duration of the journey. Large vessels (naves vivariae) used for transporting live fish long distances are attested in literature,Footnote ¹⁸ but their cargo must have been loaded onto smaller river craft, with shallower draught, to make the journey to central Rome. A boat excavated during the construction of Fiumicino airport in the 1950s demonstrates how this could have been achieved. Dated to the 2nd c. CE, the boat has a fish-well built into its hull. Holes directly under the well’s basin allowed it to be filled or replenished with seawater as needed and were plugged during transport, after the desired water level was achieved.Footnote ¹⁹ The vessel is a little over 5 m long and 1.5 m wide, with a shallow draught and a height at the edge of a little over 0.5 m, making it small enough to have navigated upriver.Footnote ²⁰ This boat and others like it could have contributed to Rome’s supply of marine fish, delivering live fish to be sold at markets and to stock artificial fishponds (piscinae).Footnote ²¹ How prevalent such vessels were and how many at a time operated on the Tiber, if they indeed navigated to the river ports in the urban center at all, are open questions. Fishing in the Tiber, a short walking distance from the Republican and later fish markets, offered more efficient and inexpensive options. The lower price, as well as the freshness of locally caught river fish, would have been especially appealing for less wealthy consumers who wished to supplement their diet with fish protein.

The river landscape, the lupus, and “two bridges”

Despite the cachet of imported species, fish from the Tiber were readily sourced. Local fishermen were even celebrated with a day of games every June, next to the Tiber on the Campus Martius. ^{Footnote 22} A handful of Tiber species appear in ancient literary sources, including the lupus or sea bass (Dicentrarchus labrax),Footnote ²³ European eel (Anguilla anguilla), and European sturgeon (Acipenser sturio).Footnote ²⁴ The context of these textual references – often in poetic discourse – complicates their usefulness as testimony for actual practice, but when considered alongside the architectural landscape of Republican and Imperial Rome they can inform us about how real, everyday practice intersected with the idealized status of fish in the popular imagination. The popular lupus fish offers the best opportunity for isolating one important fishing site, inter duos pontes (“between two bridges”), that was used during the Republican and Imperial periods.

The treatment of lupus, or European sea bass, exemplifies the Romans’ complicated relationship with the fish that came out of their local rivers. In antiquity, river fish were routinely considered subordinate to marine species, but the lupus was venerated by Romans, and those caught in the Tiber especially so. It was, and still is, a popular fish in Rome. It is the Italian spigola or branzino, a common sight at fish markets and on restaurant menus in Italy today. The lupus was considered cunning and “quick of hearing,” and was known to be voracious, fierce, and “hostile to the grey mullet” – perhaps the reason for its association with a wolf (lupus).Footnote ²⁵ Martial, a reliable source for frequent (if not entirely realistic) discussion of dinner-party fare, turns several times to the lupus as an example of high-end food.Footnote ²⁶ Pliny the Elder reported that lupus was ranked as the most favored fish and that the best of them came from rivers.Footnote ²⁷ An anecdote from Columella paints a slightly different picture: a dinner guest spits out, in disgust, a bite of river-caught lupus. But an exception is made for Tiber lupus: “[This] taught educated and refined palates to despise the river lupus, unless it was that which had tired itself out swimming against the Tiber’s current.”Footnote ²⁸ If lupus was an exception to the rule about river-caught fish, those caught in the Tiber were even more extraordinary.

The lupus was frequently said to be caught in Rome inter duos pontes (“between two bridges”) or inter pontes (“between the bridges”), a reference to one of Rome’s premier fishing spots.Footnote ²⁹ But the “two bridges” are difficult to identify. The phrase is generally taken to indicate the area where the Cloaca Maxima sewer emptied into the river, in the Forum Boarium just south of the ancient Pons Aemilius (now called the Ponte Rotto), and presumably north of the Pons Sublicius, the ancient wooden bridge thought to have lain a short distance downstream from the Cloaca’s mouth.Footnote ³⁰ The earliest examples of the phrase inter pontes come from Horace’s Sermones 2.2, which dates to about 30 BCE, and Pliny the Elder’s Naturalis Historia, ca. 70s CE.Footnote ³¹ Both texts refer to an area where lupus fish were caught. Macrobius’s Saturnalia, purporting to reproduce a speech from the 2nd c. BCE, mentions that the best lupus were inter duos pontes.Footnote ³² None of these passages identify the bridges in question.Footnote ³³ At the time when Horace and Pliny were writing, there were four bridges in Rome. The oldest was the wooden Pons Sublicius, originally built by Ancus Marcius in the late 7th c. BCE, according to later histories. It was the lone bridge in Rome for centuries until construction of the first stone bridge, the Pons Aemilius, in the 2nd c. BCE.Footnote ³⁴ An older wooden bridge might have existed on the site of the Pons Aemilius in the 3rd c. BCE.Footnote ³⁵ From 62 BCE, the Pons Fabricius connected Tiber Island to the left (eastern) bank of the river. At some point in the second half of the 1st c. BCE, the Pons Cestius was also added to connect the island to the river’s right bank (Fig. 2).

Fig. 2. Map of Rome, with locations discussed in this article. The port at Pietra Papa is out of frame, a short distance to the southwest. (Illustration: Dan Weiss, after Keay Reference Keay2012, 35.)

As it relates to a fishing site, I am inclined toward a somewhat generalized reading of inter pontes, although it is prudent to restrict it to the vicinity of the island, which offers proximity to all four of the bridges that were present in the 1st c.Footnote ³⁶ Someone using the phrase might have conceived of the bridges as a group, or as one of two pairs, and both the island and the Cloaca Maxima would have been front of mind. Even with the exact location of the Pons Sublicius still in question, we can be confident that the Cloaca Maxima would have been situated between Rome’s two earliest bridges. From the early 2nd c. BCE until the second half of the 1st c. BCE, a Roman who said inter duos pontes could have been referring to anywhere between the Pontes Sublicius and Aemilius, which included the terminus of the Cloaca Maxima’s channel. If a fishing site of considerable import was established inter duos pontes in the 2nd c. BCE, when there were only two bridges in the city, there may have been no need to specify which bridges one was talking about, even a hundred or more years later.Footnote ³⁷ From the late 1st c. BCE onward, when the Pons Fabricius and Pons Cestius connected the island to the banks on either side, the phrase might still have been used to refer to the area between the two older bridges, or to the island specifically, and it may well have indicated more generally the area of the river that encompassed both options. It is shortly after the appearance of this second set of bridges that Horace first uses inter pontes (notably not inter duos pontes) to refer to a fishing spot. Because there were eventually multiple bridges in the middle of the city, it might be more fitting to translate inter as “among” or “in the midst of” the bridges rather than “between,” and assume that Horace expected his local audience to know the general area to which he referred.

Ancient use of the phrase inter duos pontes might lack the precision that this kind of analysis seeks, but the ambiguity invites us to consider why the area would have been attractive for fishing. We might envision a tradition of fishing from Tiber Island itself, or, if the presence of the temple to Asclepius on the island discouraged that sort of commercial activity, from the banks or bridges on either side.Footnote ³⁸ The water flowing on either side of the island would have been attractive to fishermen even before it was accessible from bridges. Fish would have been funneled through the two channels, and fishermen could have used nets or traps to capture them more easily in the narrower span. These channels probably created a faster current for fish to swim against, slowing them down just at the point where fishermen could pen them in, particularly at the southern ends of the channels that circumvent the island. That this is also very near to the Cloaca Maxima on the left bank means that someone referring to fishing inter duos pontes could have had either the island or the sewer in mind – or both.

Quality concerns and pollution in the Tiber

If Romans were getting their fish from the area of the Cloaca Maxima, it would seem a particularly insalubrious venue for fishing. Some measure of pollution is certain, in the Tiber generally and near the island and the Cloaca Maxima specifically, but that did not diminish the area’s reputation as a prime fishing spot. In the surviving literature, writers cast the fish caught in the Tiber in one of two ways: either as very good, or as low quality to the point of being disgusting. Concerns about the quality of fish caught there only appear in the context of furthering some other point the writer was trying to make. Juvenal’s reference to Aurelia the fish seller is part of a longer segment concerning the “two-level hospitality” of the cena in socially stratified Rome, as part of which a patron might serve his client a Tiberinus fish that Juvenal describes as “a home-grown slave of the river’s banks, fattened by the rushing sewer and wont to swim up the drain under the middle of the Subura.”Footnote ³⁹ Likewise, the Macrobius passage describes the lupus caught between the two bridges as a “plate licker like a gourmand, because it goes after excrement next to the river banks.”Footnote ⁴⁰ The implication of these remarks is that fish caught in that area was enjoyed by unsophisticated, low-class diners who either overlooked, or perhaps even preferred tainted foodstuffs. On the other hand, some references to the Tiber’s lupus suggest a broad preference for fish caught in that very location. Pliny the Elder suggests that not only are river lupus the best, but those caught “between the two bridges on the Tiber” are the most desirable of all, and Varro also purportedly claimed that lupus from between the bridges was the very best.Footnote ⁴¹ These pronouncements reinforce Horace’s dictum that both the Tiber’s estuary and the area “between the bridges” produced good fish.Footnote ⁴² The lupus on Rome’s doorstep was comparable to fish caught in the open waters of the Mediterranean, yet it was undeservedly overlooked because it was a more commonplace sight among the market stalls of Rome. Regardless of snobbery, lupus from inter pontes seems to have been on the minds, and plates, of many people in Rome.

If the favorite fishing spot for lupus and other fish was adjacent to the Cloaca Maxima, the fish might not have lingered in the area around the sewer, or any other part of the urban river, long enough to absorb pollution to a degree that affected their appeal. Shoals of the fish returned to feeding grounds in the lower Tiber where it coursed through Rome, but sea bass are fast and strategic swimmers that move through ranges in the tens of kilometers.Footnote ⁴³ However unappealing the prospect of casting a net in a noticeably contaminated portion of the river might have been, it is possible that the effects on the purity of the fish were minimal. And, in fact, the Cloaca Maxima primarily directed water runoff from Rome’s populated valleys, not raw sewage. The ancient Tiber was used as a dumping ground and was surely polluted in general, not only directly downstream from the sewer’s outlet. Any urban fishing might have had a tinge of filth about it. The stench of sewage would certainly have been more potent during the warmer months, exacerbated by a slower flow rate in drainage channels brought on by reduced rainfall. Perhaps this made the presence of the sewer more noticeable in the general vicinity of these fishing grounds, even if the fishermen’s nets were at the southeastern end of Tiber Island, slightly upriver of the sewer.

Assessing the actual level of pollution in antiquity, either qualitatively or quantitatively, is difficult. It is clear from the references above that there was an awareness of pollution in the Tiber generally and near the Cloaca Maxima specifically, but this fact should not lead us to dismiss the Tiber as a viable source of fish resources.Footnote ⁴⁴ It is possible that reverence for the lupus and other river fish waned as Rome’s population increased along with the river’s level of pollution. The period between the late Republic and the 2nd c. CE saw an estimated fivefold increase in the population, to one million inhabitants, and the volume of waste making its way into the Tiber certainly increased as well.Footnote ⁴⁵ Pollution was inevitable, but the continued demand for fish from the Tiber can be explained by their relative affordability. In antiquity, freshwater fish were consistently less expensive than marine species, which were viewed as categorically different throughout the Mediterranean. Diocletian’s 301 CE Edict on Maximum Prices, a useful source for determining the relative costs of goods if not exact pricing, lists marine fish at twice the price of river fish.Footnote ⁴⁶ Galen attributed the cost differential to pollution and advised against daily consumption of river fish, noting that grey mullet caught in the Tiber were prone to decomposing quickly and smelling bad, which is why they were cheaper. ^{Footnote 47} But a suboptimal fish from the river would appeal to many consumers who desired seafood and could not afford the higher-priced marine imports. For people in Rome during the Republic and Principate, fish caught locally would have been a more affordable option, and those cost savings would have lured many buyers to the fish markets for local fare. The fact is that people do eat fish if they know or suspect that the water it came from was polluted. Modern studies of recreational fishermen have found that many regularly eat fish from waters contaminated by modern pollution. Making do with what one has, or accepting some drawbacks in exchange for small luxuries, is a universal reality. One study of recreational fishermen in Arizona found that people knowingly eat fish from polluted waters and also noted that many of the fisheries studied were in low-income neighborhoods – something to consider when thinking about the choices people make under less than ideal circumstances, ancient or modern.Footnote ⁴⁸

Barge traffic and the logistics of intensive fishing in central Rome

Accepting that commercial-scale fishing occurred in the vicinity of the Cloaca Maxima’s outlet and Tiber Island demands an account of the methods and ramifications of fishing there. When one thinks about the contribution of the Tiber to the vitality of Rome, it is most commonly as an avenue for transport vessels that brought essential goods up from the coast and down from the hinterlands. Indeed, thinking about provisioning the city in the late Republic and Principate, one imagines a near-constant stream of shallow-draught barges plying their way up and down the river’s channel. Following the lupus has led us to central Rome, in the middle of this busy thoroughfare. Comparative evidence for fishing installations in medieval church records also brings us to the island and Rome’s bridges, all pinch points for migrating fish and barge traffic alike. The appeal of fishing in this section of the Tiber is evident, but fishing practices, by their nature, posed a logistical problem for river navigation.

Where the river coursed through Rome, it was clogged with traffic for much of the year and was subject to intense regulation.Footnote ⁴⁹ Puteoli was Rome’s primary sea harbor during the Republic, with cargoes transferred there to smaller vessels that could be accommodated at Ostia and then sent on to Rome. The traffic along the lower Tiber increased with the construction of a harbor at Portus. Begun in 42 CE by the emperor Claudius and certainly in use by 62 CE, it was later improved with the addition of Trajan’s larger and better-protected hexagonal harbor.Footnote ⁵⁰ Johann Rasmus Brandt estimates that the Tiber was navigable for 330 days of the year and that the boats making the journey back and forth would frequently have numbered in the hundreds, with each year seeing perhaps up to 10,000 journeys.Footnote ⁵¹ This boat traffic was monitored by state entities in support of the annona. The situation was hectic and the stakes high, such that in the 1st c., the office of the curatores riparum et alvei Tiberis was created to keep things in order. Some kind of management of the shared physical space of this legally open waterway would have been necessary from the mid-Republic onward.

The activities of fishing and barge navigation were not complementary; in fact, each industry’s use of the river introduced problems for the other’s ability to exploit the same resource. Fishing on a commercial scale almost certainly required some combination of weirs or other wooden fencing, nets weighed down with stone or terracotta weights, and baskets or other fish traps positioned on the river’s bed, all technologies that are attested in the Roman period.Footnote ⁵² A combination of wicker baskets and nets affixed to wooden fencing at opportune moments – ideal for capturing eels and lupus fish, respectively – was probably needed to maximize the catch on the Tiber. Considering the ongoing need to dredge the river to keep the navigation channel clear, attested by the existence of the curatores riparum et alvei Tiberis and the work of professional divers (urinatores), such contraptions almost certainly would have interfered with this aspect of the shipping industry. Furthermore, Cassiodorus, writing in the 6th c., describes a conflict that arose when fishermen’s weirs or fencing (saepes) obstructed navigation on five rivers in mainland Italy, including the Tiber.Footnote ⁵³ This testimony suggests that nets (retia) were more acceptable than fixed wooden installations, but even temporarily deploying nets on the appropriate days – a not entirely predictable venture – would have interfered with Rome’s crushing navigation schedule.

When it comes to understanding the mechanics of fishing on the Tiber, we are well served by medieval descriptions of the practice. While political and social structures in Rome had changed by that time, many of the same species of fish were sought on a commercial scale, and in an environment that was similarly crowded and flood-prone.Footnote ⁵⁴ In terms of navigability, in the 14th and 15th c., the Tiber was still teeming with vessels and was also the site of numerous other industrial activities, including milling, tanning, potting, and brickmaking.Footnote ⁵⁵ Ecclesiastical records, for which there is no analogue in antiquity, offer a window into the logistics of fishing on a busy Tiber in the middle of Rome. Fisheries in the medieval period often clustered in precisely the high-traffic commercial zones that would have been both desirable and problematic for their ancient counterparts. Fishing jetties were common despite the risk of flooding, and people were loath to give up their preferred spots to facilitate flood abatement interventions.Footnote ⁵⁶ Dozens of church-owned fisheries were scattered along the Tiber’s banks, targeting many of the same species discussed by ancient authors. According to a declaration by Pope Gregory IX in 1233, the monastery of Santa Maria di Grottaferrata owned two fisheries situated on the Tiber in the city of Rome: one to capture sturgeon near the Ripa Romea (the future site of the Ripa Grande in Trastevere between Tiber Island and Porta Portuensis), and the other near Ponte Rotto (once the Pons Aemilius), to capture shad, eels, and other fish.Footnote ⁵⁷ The location of medieval fisheries suggests that fishermen targeted stretches of river in which large nets or wooden weirs could be installed, preferably at points where fish could be funneled into a narrowing channel during their typical migrations, as between bridge pylons. The areas underneath the arches of bridges were sought after for numerous commercial activities in addition to fishing, including water mills and floating workshops. Wooden fishing platforms in these areas were leased out by churches for periods ranging from around five to 12 years.Footnote ⁵⁸ Records dated to 1477 describe one such fishing platform that had been owned by the Basilica of Santa Maria in Trastevere for more than 400 years and was situated between the pylons of the recently restored Ponte Sisto, formerly the Pons Aurelius.Footnote ⁵⁹ The long-term patterns – S. Maria in Trastevere’s shad fisheries existed from at least the 11th c. to the late 15th c. – speak to the prolonged suitability of bridges for targeting fish.Footnote ⁶⁰ We should expect that fishing installations along the banks and underneath bridges, making use of the pylons, were a common sight in the Roman period as well. Bridges were natural places for fishing activity, not least because their shade offered some relief from the intense summer heat. They might also have facilitated foot traffic, if we are to imagine that some fish were sold right on the banks, circumventing the formal market altogether. The narrowed channels on either side of Tiber Island would have been appealing for the same reason.

In addition to knowing the locations of commercial fishing, we must also understand when it took place relative to shipping seasons. To do so, it will be helpful to determine which part of the life cycle of the lupus led them to the Cloaca Maxima and Tiber Island. Change in water temperature is the driving factor behind the timing of long-distance fish migrations, and we should bear in mind that climatic conditions and anthropogenic impacts could by today have changed water temperatures enough to disrupt the migration patterns that existed in antiquity. Still, modern studies of sea bass are helpful for understanding broad patterns of behavior and habitat, although there is a great deal of regional variation. Sea bass can tolerate a wide range of temperatures (5–28 °C) and salinity levels (3 percent to full-strength seawater), making them adaptable to a variety of habitats.Footnote ⁶¹ This adaptability is an integral feature of their life cycle. They spawn in the open sea but spend much of their lives near the coast, in lagoons, estuaries, and rivers. Sea bass are slow growing, with juveniles spending their first few years in brackish lagoons and estuaries, expanding their territorial range as adolescents, and only reaching maturity at around four to five years old, at which point the speed and distance of their movements increase greatly. In Italy today, European sea bass generally spawn in the Mediterranean from December to March and overwinter in the deeper waters there. In spring and early summer, adult bass migrate back to inshore feeding grounds, preferring shallow waters and riverbanks.Footnote ⁶² European sea bass have been shown to return to the same feeding grounds year after year, and it is not unreasonable to expect that large shoals of lupus were a regular and predictable presence in the Tiber during the Roman period.Footnote ⁶³ They still make their way upriver on occasion to the center of Rome, although it is a far rarer occurrence now than it was in antiquity.Footnote ⁶⁴ Ancient sources reported that the lupus spawned in winter and again in late summer. ^{Footnote 65} Horace’s lupus thrashing about near the river’s mouth would have presumably been younger juvenile specimens – not necessarily harder to catch, but less convenient to transport to the intra-city fish markets than fish caught right between the bridges in central Rome. The latter were likely at least four to five years old, the age at which they begin to travel greater distances inland.

The big migrations of sea bass (lupus), shad, and eels overlapped with the busiest sailing season on the Tiber, upon which the city relied for the distribution of imported goods. Fishing access in the face of boat traffic posed a challenge, and the legal landscape did not offer immediate solutions. The legal and social structures that existed during the Republic and Principate did not allow for the type of continuous ownership of fishing jetties that was possible under Christian authority.Footnote ⁶⁶ According to Roman law, fishermen and other users who wished to access a public river were on a more-or-less equal legal footing. Fishing required the use of riverbanks and the river’s channel, and some of its methods ran counter to the needs of the shipping industry, which had to keep traffic flowing smoothly, to dredge the channel to allow for passage of transport vessels, and to keep the banks clear so men and animals could run towlines. The jurist Ulpian explains that impeding foot traffic alongside a river was prohibited because it compromised navigation, a reference that seems to refer obliquely to the activities undertaken by the helciarii who hauled barges upriver, running towlines from the banks.Footnote ⁶⁷ But the river was a public resource that anyone could use freely, just like air, the sea, and the seashore.Footnote ⁶⁸ Also public was that portion of a riverbank that would contain the water at its fullest; that is, up to the point where the slope levels off.Footnote ⁶⁹ The Tiber’s channel and the public part of its banks were common-pool resources to be shared by everyone.Footnote ⁷⁰ And yet, disagreements and imperial rescripts described by jurists tell us that, in practice, some intervention was needed in order for users to share public rivers.Footnote ⁷¹ There is ample documentary evidence from throughout the Empire of water-distribution disputes that illustrate the challenges faced by local officials attempting to reconcile the needs of private property owners and farmers who relied on shared water sources. But, unlike those situations, the grievance here was not that one party was diverting water that had traditionally been used by others downstream, or concerns about exhausting the water supply in the service of private uses like irrigation.Footnote ⁷² On the Tiber, the scarcity was spatial in nature. Transport vessels and fishermen were both entitled to access, but the activities of each were a hindrance to the operations of the other.

Professional corpora and enabling river access

The situation on the Tiber no doubt resulted in the need for cooperation among several parties: fishermen who hoped to exploit the river’s bounty of fish; shippers, organized into professional corpora by the early 2nd c. CE and contracted by the praefectus annonae to facilitate the transportation of grain to Rome; and eventually the curatores, whose job it was to maintain a clear channel for navigation. Whereas unmanaged use of the Tiber for commercial purposes would have invited competition between these groups, epigraphic testimony for professional corpora suggests that, during the Principate, members of the industries in question worked together in some capacity. The nature of these collaborations is not made explicit, so we can only speculate. One scenario, that professional corpora helped enforce an embargo on boat traffic around Tiber Island, would explain how intensive fishing could occur in central Rome while boat traffic continued around it. This scenario also refines our understanding of the procedures by which barges navigated to and from Rome’s river wharves.

As we might expect, the epigraphic record offers another perspective on the Roman fishing industry, one that can help us trace the contours of negotiations and labor on the Tiber. Numerous inscriptions refer to the shippers who delivered goods from the harbor at Portus to Rome’s warehouses, and five surviving inscriptions attest to professional relationships, dated ca. 100 CE to ca. 400 CE, between those shippers and fishermen.Footnote ⁷³ Many of the known corpora of shippers and boatmen seem to have been created under Trajan, possibly to facilitate the state’s ability to control the increased flow of imports coming into the city after the creation of the hexagonal harbor at Portus.Footnote ⁷⁴ Shippers (navicularii) were contracted by the praefectus annonae, who, if Boudewijn Sirks is correct, had the capacity to press shipping corpora into service when extraordinary labor was needed. For fishermen, membership in a corpus that had social and political relationships with shippers may have presented an opportunity to survive in an increasingly cutthroat commercial landscape. The benefit of this type of professional membership is alluded to on a monument dedicated, under Caracalla, to a T. Claudius Severus. The inscription (CIL VI 1872) explains that the man was decurial lictor and patron of the association of fishermen and divers (corpus piscatorum et urinatorum), and “by his assiduousness a right to navigate skiffs (navigatio scapharum) was secured and was confirmed by decree for the order of the association of fishermen and divers of the entire channel of the Tiber.” In this case, it is not clear whether the fishermen were transporting products from Ostia straight to Rome or whether they fished along the way. What is clear is that they, as well as other barge operators who appear in inscriptions from Ostia, needed permission to access the Tiber’s channel. Although the river was a public resource, Rome could not afford for the transportation industry to encounter obstacles to delivering goods, including the grain, wine, and oil on which the city’s population depended, and as such, traffic had to be managed.Footnote ⁷⁵ The relative power and influence of the shipping industry could explain the rationale for fishermen entering into professional associations with its members. If permission was needed to navigate the public waters of the Tiber, one must assume that similar permission was needed to successfully fish in those same waters. After all, navigating skiffs along a congested river is one thing; setting up fishing installations in the water to catch large quantities of migrating fish, and clogging the banks with nets and processing activities, is quite another – one that would require a much greater concession from the curatores and barge operators.

We may speculate as to how both industries thrived in central Rome by considering not only what fishing and barge transportation had in common – a need to access the river – but also the ways in which their needs were different. The bridges that were good for fishing posed a problem for navigation, because towing upstream using either men or oxen required access and movement between boat and bank.Footnote ⁷⁶ There is no evidence that towpaths extended under Rome’s ancient bridges, although the dynamic nature of the city’s riverbanks in the intervening centuries precludes a definite conclusion in this regard.Footnote ⁷⁷ Where towpaths did exist on both banks between Ostia and the southern ports of Rome, we should imagine traffic moving upriver along each bank, with a third lane of boats in the middle returning downstream.Footnote ⁷⁸ The narrow channels around Tiber Island would have made through traffic difficult, creating a serious bottleneck if all three lanes converged before attempting to pass the island. Furthermore, the faster current in the channels themselves would also have made passage hazardous, especially for the codicariae that transported larger cargoes from Ostia and Portus.Footnote ⁷⁹ Just as it might stymie a shoal of migrating fish, that current could also have posed problems for boats.

The challenge of passing bridges and navigating the suddenly narrowed channels around Tiber Island might have created a sector where it was preferable to halt most river traffic. Scholars have previously observed that the locations of port facilities suggest that a majority of shipping traffic occurred in northern and southern zones, with Rome’s southern port facilities providing the northbound destination for boats traveling from Ostia and Portus, and the smaller northern ports providing a stopping point for southbound vessels.Footnote ⁸⁰ In fact, there seems to have been little reason for barges to ever pass Tiber Island. Those coming in from Ostia and Portus need not have navigated beyond the river ports south of the Pons Sublicius: from 193 BCE, there was the Emporium; a Trajanic port was added just south of that; and another port, still farther south on the right bank at Pietra Papa, was added in the high Imperial period.Footnote ⁸¹ Cargo could be transferred to carts at the southern river wharves for final distribution around the city, or, for any goods destined to go upriver, transported to the northern Campus Martius for transshipment. Goods being conveyed downriver from the northern hinterlands, like timber, wine, produce, and construction materials, might have ventured no farther south than the ports north of the island.Footnote ⁸² Quay structures have been excavated at Tor di Nona, Piazza Nicosia, and the Ripetta, in the areas south and east of the mausoleum of Hadrian (see Fig. 2).Footnote ⁸³ A division of shipping zones is supported by epigraphic evidence. Inscriptions refer to two groups of bargemen, caudicarii, who moved cargo on the Tiber: the codicari naviculari infra pontem Sublicium (CIL XIV 185, 3rd c. CE) and the codicari naviculari infernates (CIL XIV 131, first third of 4th c. CE). Their existence implies that, if these men worked below the Pons Sublicius or otherwise in “lower regions” (infernates), there were presumably other caudicarii who worked exclusively to the north. Lionel Casson remarks that this is “a natural division that reflects the different conditions and nature of service involved” on the stretches of river between Ostia and Rome, and between Rome and the northern wharves.Footnote ⁸⁴ Antonio Aguilera Martín claims that the groups identified in the two inscriptions likely represent an evolution of the same corpus; he suggests that construction of the Pons Probi in the 3rd c. CE created a new upper limit for towing barges upriver and thus defined a new boundary for operators, whereas before that the limit had been the Pons Sublicius.Footnote ⁸⁵

A previously unexamined byproduct of such an arrangement is that it would have left a traffic-free zone around Tiber Island, opening up that space for other users of the river in precisely the area where commercial fishing was known to take place. There, the regulations imposed by the curatores riparum et alvei Tiberis elsewhere on the river were likely eased, and the fishermen’s apparent connections to the caudicarii, who themselves had a special relationship with the curatores, might have worked to their advantage. We do not know the precise nature or extent of the relationships between the different professions who were members of professional corpora. Perhaps fishermen helped facilitate cargo transfers from caudicarii to linters and other small boats, or onto carts to be transported on land. Much of the work done on docks would have benefited from additional hands at busy moments, and an existing professional alliance would have made fishermen a natural source of occasional labor. Alternatively, the relationship might have been less about physical interaction and more about who was running the businesses at a higher level. The people who appear in inscriptions at Ostia seem to be mid- to high-level players in their respective trades, rather than the actual workers on the boats.Footnote ⁸⁶ Businessmen and managers used corpora to facilitate access to resources and to manage their industries. Their influence was likely an important factor in negotiating who used the river and when. In more rural areas, fishermen could probably rely on informal agreements to gain access to fishing spots. More than one jurist expressed the opinion that if someone had fished in a particular branch of a public river for many years, he could prevent another from doing the same.Footnote ⁸⁷ This describes a system where there is an assumption of open access, but in which informal quasi-ownership was managed in some way by those who made up the fishing community.Footnote ⁸⁸ This phenomenon can be observed among modern fishing populations as well.Footnote ⁸⁹ Importantly, the communities imposing regulations in those cases are the users of the resource, not the community at large. In this sense, we can imagine that the people running commercial fishing operations at Rome were able to claim the right of first refusal on the waters around Tiber Island by virtue of their involvement in certain professional corpora.

Maintaining a relatively barge-free central zone in the middle of Rome would have meant that the river’s channel and banks were available in precisely the location of the famed lupus fishing site. Although it should be expected that there was some boat traffic for most of the year, the primary sailing season was from spring to late autumn, overlapping with many of the fish migrations commercial fishermen would wish to exploit. ^{Footnote 90} The lupus, for example, embarked on its migration downstream to spawn in winter, coinciding with subdued river traffic. But by spring and summer, shoals would have been back to their usual feeding grounds in the lower Tiber. And Pliny says that the lupus spawned again in the summer, which would have been at the height of sailing season.Footnote ⁹¹ Likewise, the shad spawned in early spring, just when river traffic was ramping up. With the area around Tiber Island relatively clear of shipping activities, fishermen could drop nets or install weirs even at the height of sailing season, intercepting fish to be sold in the nearby fish markets without disrupting the normal flow of barge traffic and delivery of other goods and foodstuffs.

The location of the Portus Tiberinus raises questions about whether boats coming from the south would have had to clear the bridges in order to reach it. Its precise location is not known, but it was somewhere in the Forum Boarium near the Theater of Marcellus (see Fig. 2).Footnote ⁹² This was Rome’s old river port, in service from the 6th c. BCE. The volume of goods arriving at the Portus Tiberinus diminished in the years following the construction of the Emporium port facilities, as the latter were more suited to receiving the large quantities of cargo delivered from Spain and North Africa from the late 2nd c. BCE onward. But the Portus Tiberinus was still used in some capacity during the Imperial period; horrea that presumably stored grain were constructed nearby under Trajan.Footnote ⁹³ For much of its lifespan, the only bridge that northbound boats needed to pass was the wooden Pons Sublicius. Perhaps this bridge was an obstacle but could be surpassed by helciarii when necessary, without a proper towpath. Aguilera Martín notes that one advantage of humans over oxen in this regard is that they can more easily improvise and maneuver along the variable terrain on a river’s banks, whereas beasts of burden require more clearance and a smoother, prepared path.Footnote ⁹⁴ Towing barges under the Pons Sublicius may have become less convenient as the bridge was repeatedly reconstructed over the centuries, and it was impossible using the oxen that hauled heavier barges from Ostia to the Emporium.Footnote ⁹⁵ Such logistical difficulties might have been a contributing factor in the Portus Tiberinus’s decline in favor of the southern wharves. Nevertheless, occasional traffic may have been allowed through, and in those situations, the organizational influence of the corpora of shippers and fishermen would have become key.

These negotiations, including a restriction on barge traffic passing Tiber Island, could have continued at least until the 3rd c. CE, when the southern sector’s utility as a zone of river ports was compromised by a flood abatement wall and the construction of the Aurelian Wall at the site of the Emporium.Footnote ⁹⁶ There remained a tradition of using smaller docks to transfer cargo to carts or smaller boats for conveyance northward. Indeed, the references to barge operators working below the Pons Sublicius and the Pons Probi can be dated to the mid-3rd to early 4th c. CE. And notably, corpora that linked fishermen and barge owners persisted as well, specifically in the urban environs of Rome: one inscription (CIL VI 41382) that mentions the corpus of boatmen and fishermen who operated in the city (caudicarii seu piscatores corporati urbis Romae) – as opposed to other groups who worked in the rich lagoon environment near the mouth of the Tiber at Ostia – dates to around 400 CE, suggesting that those collegial relationships had still by then not outlived their usefulness.