Is Fish Farming the Generator of Many of the World's Civilizations?/info

Introduction

The conventional narrative of civilizational origins emphasizes grain agriculture — wheat in Mesopotamia, rice in East Asia, maize in Mesoamerica — as the foundational subsistence strategy that enabled population growth, social stratification, and urban development. A growing body of archaeological evidence, however, suggests that intensive aquaculture and water management may have played an equally fundamental role in the emergence of complex societies across multiple independent regions. From the raised-field systems of Amazonian Bolivia to the canal-and-reservoir networks of the ancient Maya lowlands, societies that engineered aquatic landscapes to produce fish, turtles, waterfowl, and aquatic plants achieved population densities and social complexity comparable to grain-based civilizations.

The Casarabe culture of the Llanos de Mojos in northern Bolivia (c. 500–1400 CE) provides a particularly compelling case study. Recent lidar surveys have revealed a network of low-density urban settlements linked by hundreds of kilometres of causeways and canals, with monumental platforms, pyramids, and extensive water management infrastructure. The Casarabe engineered their savanna landscape to create ponds, drainage channels, and raised fields that simultaneously managed seasonal flooding, enabled multiple crop harvests, and produced aquatic protein. Similar strategies have been documented among the ancient Maya of the Yucatán and Petén lowlands, where canal systems associated with raised agricultural fields functioned as integrated aquaculture systems.

The hypothesis that aquaculture was a "generator" of civilization rather than merely a supplement to agriculture reframes the relationship between water management and social complexity. If the engineering of aquatic landscapes was a necessary condition for urbanization in tropical lowland environments — where grain monoculture was often impractical — then the origins of civilization are more diverse and more intimately connected to water than the grain-centric model suggests.

What we know

The Casarabe culture, also known as the Mojos culture, occupied the seasonally inundated savannas of the Llanos de Mojos in the Beni Department of Bolivia. The region experiences extreme seasonal variation: during the wet season (November–April), vast areas are submerged under floodwater; during the dry season, the same areas become parched grassland. The Casarabe response to this challenging environment was the construction of an extensive hydraulic landscape: raised agricultural platforms above flood level, interconnected by causeways, with drainage canals and retention ponds that stored water during the dry season and managed flow during the wet season.

The 2022 lidar survey led by Heiko Prümers of the German Archaeological Institute, published in Nature, revealed the scale of Casarabe settlement for the first time. The survey documented two remarkably large sites — Cotoca and Landívar — featuring monumental earthen platforms up to 22 metres high, civic-ceremonial architecture, and extensive water management infrastructure. Around these primary centres, a hierarchy of smaller settlements was distributed across the landscape, connected by causeways extending for kilometres. The total surveyed area covered approximately 4,500 km², revealing a pattern of low-density urbanism that challenges traditional definitions of the "city."

The Casarabe water management system served multiple functions simultaneously. The raised fields created elevated surfaces for maize and other crops, insulated from seasonal flooding. The canals between the fields served as fish ponds, providing aquatic protein. The system also managed water flow across the landscape, directing seasonal floodwaters into retention areas and distributing stored water during dry periods. This integration of agriculture, aquaculture, and hydrology into a single engineered landscape represents a sophisticated approach to tropical subsistence that does not fit neatly into categories derived from temperate grain agriculture.

Among the ancient Maya, analogous systems have been documented in multiple regions. The canals associated with raised agricultural fields in northern Belize, the Petén lakes region of Guatemala, and the bajos (seasonal wetlands) of the central lowlands functioned as integrated subsistence systems in which agriculture and aquaculture were inseparable. Joel Palka's research, published in Ancient Mesoamerica in 2023, argues that Maya aquaculture was not a supplementary activity but a central component of Maya subsistence — as important as maize cultivation. The Maya modified waterscapes to increase production of fish, turtles, waterfowl, and aquatic plants, creating "domesticated waterscapes" that functioned as multi-trophic aquaculture systems.

Similar patterns have been identified in other regions. In Southeast Asia, the extensive water management systems of Angkor (9th–15th centuries CE) combined rice paddy agriculture with fish cultivation in a landscape-scale hydraulic system. In China, integrated rice-fish farming has a documented history extending at least 2,000 years. In western Africa, the inland Niger Delta's flood-recession agriculture and fisheries supported urban centres including Djenné-Jeno (established c. 250 BCE).

The global pattern suggests that intensive water management and aquaculture were not peripheral activities adopted after civilizations were established through grain agriculture, but were in many cases co-foundational — integral to the subsistence strategies that enabled population growth and social complexity in the first place.

Classification of theories

A. Plausible explanations (supported by evidence, not refuted):

1. Aquaculture as co-foundational in tropical lowland civilizations: In environments where grain monoculture was impractical (seasonal wetlands, tropical forests), integrated water management and aquaculture provided the subsistence base for complex societies. The evidence from the Casarabe, Maya, and Angkorian civilizations supports this interpretation.

1. Water management as a driver of social complexity: The construction and maintenance of large-scale hydraulic infrastructure required coordinated labour and centralized management, driving the development of social hierarchy and administrative structures — consistent with Wittfogel's "hydraulic hypothesis" as modified by subsequent scholarship.

B. Possible explanations (raised by researchers, less well supported):

1. Aquaculture as universally necessary for civilizational emergence: The stronger claim that all or most early civilizations depended on some form of aquatic resource management. While suggestive, the evidence does not clearly support this universality, as some civilizations (e.g., highland Mesoamerica, parts of Mesopotamia) developed primarily through dryland grain agriculture.

1. Fish protein as the critical enabling factor: The specific claim that aquatic animal protein (rather than water management in general) was the key resource enabling population growth. While nutritionally significant, the relative importance of fish versus plant-based calories varies by region and period.

C. Highly unlikely but argued by some:

1. Single origin of aquaculture technology: The claim that all ancient aquaculture systems derive from a single original culture that diffused the technology globally. The independent development of aquaculture in multiple regions, using different species and different engineering approaches, argues against any single-origin model.

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Research Papers

Landmark Studies

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1. Prümers, H., Betancourt, C.J., Iriarte, J., Robinson, M. & Schaich, M. (2022). "Lidar reveals pre-Hispanic low-density urbanism in the Bolivian Amazon." Nature, 606, 325–328. DOI: 10.1038/s41586-022-04780-4

Full text: https://www.nature.com/articles/s41586-022-04780-4 [publisher paywall]

[Publisher abstract]

"Two remarkably large sites in southwest Amazonia, belonging to the Casarabe culture, include complex civic-ceremonial architecture and large water-management infrastructure, representing a type of tropical low-density urbanism that has not been previously described in Amazonia."

Full-text notes:

Prümers et al.'s lidar survey is transformative for understanding both the Casarabe culture and the broader phenomenon of tropical urbanism. The revelation of monumental platforms (up to 22 m high), causeways extending kilometres, and canals managing water across thousands of square kilometres demonstrates a level of landscape engineering that was previously unknown in Amazonia. The water management infrastructure — canals, reservoirs, and raised fields — is not incidental to the settlement pattern but integral to it: the urban system and the hydraulic system are the same thing.

The paper's adoption of the "low-density urbanism" framework, developed for the analysis of Angkor and Maya settlements, positions the Casarabe within a global pattern of tropical civilizations that distributed their populations across engineered landscapes rather than concentrating them in dense urban cores. This pattern, characterized by extensive rather than intensive land use, is fundamentally dependent on water management technology.

The implications for the aquaculture-civilization hypothesis are significant. The Casarabe engineered their landscape specifically to create productive aquatic environments — the canals and ponds were designed features, not by-products — suggesting that aquatic resource production was a primary goal of the hydraulic system rather than a secondary benefit.

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2. Palka, J.W. (2023). "Ancestral Maya domesticated waterscapes, ecological aquaculture, and integrated subsistence." Ancient Mesoamerica, 34(1), 155–178. DOI: 10.1017/S0956536122000402

Full text: https://www.cambridge.org/core/journals/ancient-mesoamerica/article/ancestral-maya-domesticated-waterscapes-ecological-aquaculture-and-integrated-subsistence/9C24BC7A4785C76D26C0E70CE6ABDA82 [publisher paywall]

[Publisher abstract]

"Canals and reservoirs, however, also supported multi-trophic ecological aquaculture. Maya created multi-trophic ecological aquaculture by modifying the waterscape to increase the amounts of foods and useful materials, such as fish, turtles, waterfowl, and reeds."

Full-text notes:

Palka's contribution is significant because it reframes Maya water management from a purely agricultural context to an integrated aquacultural one. Previous scholarship on Maya raised-field agriculture focused on maize and other crops; Palka argues that the aquatic environments created by the canal systems were equally productive and equally intentional. The Maya "domesticated" their waterscapes to create environments favourable for desirable aquatic species, managing water levels, nutrient flows, and habitat features to maximize aquatic production.

The multi-trophic model — in which different levels of the aquatic food web were simultaneously managed and harvested — represents a degree of ecological sophistication that parallels modern aquaculture principles. The Maya were not simply catching wild fish in convenient locations but engineering entire aquatic ecosystems for sustained production.

The implications extend beyond the Maya. If aquaculture was integral to Maya subsistence, analogous investigations at other civilizational sites with water management infrastructure could reveal similar patterns. The canal systems of Angkor, the chinampas of the Basin of Mexico, and the irrigation networks of Mesopotamia may all have had aquacultural dimensions that have been overlooked.

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3. Erickson, C.L. (2000). "An artificial landscape-scale fishery in the Bolivian Amazon." Nature, 408, 190–193. DOI: 10.1038/35041555

Full text: https://www.nature.com/articles/35041555 [publisher paywall]

[Publisher abstract]

"Here I present evidence that the pre-Columbian inhabitants of the Bolivian Amazon constructed an artificial landscape-scale fishery. An extensive network of earthen weirs and ponds was used to trap, store, and harvest fish during the annual flooding cycle."

Full-text notes:

Erickson's earlier work in the Llanos de Mojos established the foundational evidence for pre-Columbian aquaculture in Amazonia. By documenting the zigzag weirs (fish traps) and associated pond systems in the Baures region, he demonstrated that indigenous peoples had engineered landscape-scale aquatic harvesting systems that operated on the seasonal flood cycle. Fish were trapped as floodwaters receded, concentrated in ponds, and harvested during the dry season — a sustainable management strategy that converted the seasonal flood from a challenge into a resource.

This paper is a landmark because it provided the first rigorous archaeological evidence for deliberate fish management in pre-Columbian South America. The zigzag weir systems covered hundreds of square kilometres, indicating that aquatic resource management operated at a landscape scale comparable to agricultural systems. The estimated productivity of these systems — tonnes of fish annually — suggests they could have supported substantial populations.

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4. Scarborough, V.L. (2003). The Flow of Power: Ancient Water Systems and Landscapes. SAR Press. ISBN: 978-1930618169

Full text: https://www.worldcat.org/search?q=978-1930618169 [WorldCat link unverified — ID may be incorrect]

[Agent-generated summary]

Scarborough's comparative analysis of water management systems across multiple ancient civilizations — Maya, Angkorian, Mesopotamian, and others — argues that the control of water was a fundamental mechanism of political power in early states. The book examines how hydraulic infrastructure served simultaneously as a subsistence technology, a medium of political authority, and a landscape of symbolic meaning.

Full-text notes:

Scarborough's work provides the theoretical framework for understanding aquaculture within the broader context of water and power. His analysis demonstrates that water management systems were never purely utilitarian: they structured settlement patterns, defined social hierarchies, and expressed cosmological beliefs. The construction and maintenance of canals, reservoirs, and raised fields required coordinated labour and centralized management, creating the administrative structures that became the foundation of state authority.

The book's comparative approach is particularly valuable because it identifies common patterns across independent civilizations. Whether in the Maya lowlands, the Angkorian plain, or the Llanos de Mojos, the relationship between water management and social complexity follows similar trajectories: small-scale water management enables population growth, which necessitates larger-scale management, which requires more complex social organization, which further enables hydraulic expansion. This positive feedback loop may be a general mechanism for civilizational emergence in environments where water management is critical.

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5. Lombardo, U. & Prümers, H. (2010). "Pre-Columbian human occupation patterns in the eastern plains of the Llanos de Mojos, Bolivian Amazonia." Journal of Archaeological Science, 37(8), 1875–1885. DOI: 10.1016/j.jas.2010.02.011

Full text: https://www.sciencedirect.com/science/article/abs/pii/S0305440310000658 [publisher paywall]

[Agent-generated summary]

An analysis of settlement patterns in the Llanos de Mojos based on remote sensing and field survey, documenting the relationship between pre-Columbian settlements and hydraulic infrastructure. The study establishes that settlements were systematically located in relation to water management features, confirming the integration of habitation and hydrology.

Full-text notes:

Lombardo and Prümers demonstrate the intimate relationship between settlement location and hydraulic infrastructure in the Llanos de Mojos. Their analysis shows that pre-Columbian mound settlements are consistently associated with canals, raised fields, and fish weir systems, suggesting that the selection of settlement sites was driven by access to engineered aquatic resources rather than by topographic or defensive considerations alone.

This spatial analysis supports the interpretation of the Casarabe landscape as an integrated agro-aquacultural system in which habitation, farming, and fishing were organised as a single operational unit. The pattern is consistent with a society whose subsistence depended on the simultaneous management of terrestrial and aquatic resources.

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Recent Studies

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6. Iriarte, J., et al. (2020). "Geometry by design: Contribution of lidar to the understanding of settlement patterns of the mound villages in SW Amazonia." Journal of Computer Applications in Archaeology, 3(1), 151–169. DOI: 10.5334/jcaa.45

Full text: https://journal.caa-international.org/article/10.5334/jcaa.45/ [open access]

[Agent-generated summary]

Lidar analysis of mound village settlement patterns in southwestern Amazonia, revealing geometric planning in village layout and systematic spatial relationships between settlements and water management features.

Full-text notes:

Iriarte et al. demonstrate that Casarabe settlements were not organically developed but deliberately planned according to geometric principles. The circular and U-shaped village layouts, combined with systematic causeway orientations and canal alignments, indicate centralized planning and cosmological orientation. This evidence for deliberate landscape design strengthens the interpretation of the Casarabe as a complex, hierarchically organized society whose spatial order was expressed through hydraulic and settlement planning simultaneously.

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7. Fletcher, R. (2012). "Low-Density, Agrarian-Based Urbanism: Scale, Power, and Ecology." In The Comparative Archaeology of Complex Societies, edited by M.E. Smith, 285–320. Cambridge University Press. DOI: 10.1017/CBO9781139022712.014

Full text: https://www.cambridge.org/core/books/abs/comparative-archaeology-of-complex-societies/ [publisher paywall]

[Agent-generated summary]

Fletcher's theoretical framework for "low-density urbanism" provides the analytical vocabulary for understanding tropical civilizations like the Casarabe and Angkor that distributed their populations across extensive, engineered landscapes rather than concentrating them in dense urban cores.

Full-text notes:

Fletcher's framework is essential for understanding why civilizations based on aquaculture and water management may not resemble the grain-based urban centres of Mesopotamia or the Mediterranean. Low-density urban systems occupy much larger areas, have lower population densities, and depend on distributed rather than centralized infrastructure. Their "cities" are landscapes rather than bounded settlements, making them difficult to detect through traditional archaeological methods but increasingly visible through remote sensing technologies like lidar.

The framework explains why Amazonian civilizations were long dismissed as non-existent: they did not match the expected pattern of nucleated urbanism derived from Old World exemplars. The discovery of Casarabe, Kuhikugu, and other Amazonian civilizations through lidar is simultaneously a discovery of new archaeological sites and a reconceptualization of what "civilization" means in tropical environments.

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8. Scarborough, V.L. & Gallopin, G.G. (1991). "A Water Storage Adaptation in the Maya Lowlands." Science, 251(4994), 658–662. DOI: 10.1126/science.251.4994.658

Full text: https://www.science.org/doi/10.1126/science.251.4994.658 [publisher paywall]

[Publisher abstract]

"The ancient Maya at Tikal and other cities constructed extensive water storage systems including reservoirs, canals, and dams to manage seasonal water availability. These systems were integral to Maya urban planning and subsistence."

Full-text notes:

Scarborough and Gallopin's demonstration that Maya cities were designed around water management infrastructure — with reservoirs, canals, and dams integrated into the urban plan — establishes the centrality of water control to Maya urbanism. While this study focuses on water storage for drinking and irrigation, the infrastructure it describes is the same infrastructure that Palka (2023) later identified as supporting aquaculture. The overlap between agricultural water management and aquaculture is a key insight: the same canals and reservoirs that watered crops also produced fish.

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Current Discussions

1. ScienceDaily (2022) — "Archaeologists reveal pre-Hispanic cities in Bolivia with laser technology." Coverage of the Prümers et al. lidar survey. https://www.sciencedaily.com/releases/2022/05/220525110924.htm [open access]

1. The Guardian (2022) — "Digital mapping reveals network of settlements thrived in pre-Columbian Amazon." Report on the Casarabe discoveries. https://www.theguardian.com/science/2022/jun/02/amazon-rainforest-archaeology-settlements-bolivia-casarabe [open access]

1. ASU News (2023) — "ASU archaeologist on the importance of waterscapes in ancient Maya culture." Interview with Joel Palka discussing Maya aquaculture research. https://news.asu.edu/20230815-asu-archaeologist-highlights-importance-waterscapes-ancient-maya-culture [open access]

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Future Research Directions

The extension of lidar survey coverage across the Llanos de Mojos could dramatically expand the known extent of Casarabe settlement and water management infrastructure. The 2022 survey covered approximately 200 km² of a region estimated at 4,500 km² — less than 5% of the Casarabe territory. Full coverage could reveal the complete settlement hierarchy, canal network, and landscape engineering pattern, enabling quantitative assessment of the system's productivity and carrying capacity.

Zooarchaeological analysis of faunal remains from Casarabe settlements is critical for establishing the actual contribution of aquatic resources to the diet. While the hydraulic infrastructure is consistent with aquaculture, direct evidence of fish consumption — fish bones, scales, processing tools — from stratified archaeological contexts would strengthen the case. Similar analysis at Maya sites with canal systems could quantify the relative importance of aquatic versus terrestrial protein.

Comparative analysis across independent aquaculture-based civilizations — Casarabe, Maya, Angkorian, Tiwanaku, and others — could identify common patterns in the relationship between water management and social complexity. Such analysis could determine whether there are general thresholds of hydraulic investment that correlate with specific levels of social stratification, administrative complexity, or population density.

Experimental archaeology — reconstructing and operating sections of ancient canal-and-pond systems — could provide productivity data needed to model the carrying capacity of aquaculture-based subsistence systems. Such experiments have been conducted for Maya raised fields but not specifically for their aquacultural function, and no systematic experimental work has been done on Casarabe fish weir systems.

The integration of palaeoenvironmental data (pollen, phytoliths, charcoal, sedimentary geochemistry) with archaeological data from aquaculture sites could reconstruct the long-term environmental impacts of intensive water management. Understanding whether these systems were ecologically sustainable over centuries — or whether they degraded their resource base, potentially contributing to civilizational collapse — has obvious relevance to contemporary sustainability debates.

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Summary of Existing Research and Public Opinion

The proposition that aquaculture was a foundational subsistence strategy for multiple independent civilizations is supported by growing archaeological evidence from South America, Mesoamerica, and Southeast Asia. The Casarabe lidar discoveries and Maya aquaculture research have generated significant scholarly interest and are reshaping understanding of tropical civilizational emergence. The traditional grain-centric model of civilizational origins is being expanded — not replaced — to include aquatic resource management as a parallel pathway to social complexity.

Public awareness of these findings is growing but remains limited. The 2022 Casarabe lidar results received substantial media coverage, but the specific role of aquaculture in supporting these civilizations has received less attention than the dramatic imagery of "lost cities in the Amazon." The Maya aquaculture research has been covered primarily in specialist outlets. The broader synthesis — that water management and fish farming may have been as important as grain agriculture in the origins of civilization — has not yet entered mainstream public understanding.

The evidence is strongest for tropical lowland environments where seasonal flooding creates both challenges and opportunities for aquatic resource management. Whether the aquaculture-civilization hypothesis extends to temperate or arid-zone civilizations remains an open question that requires further investigation.

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Where Do I Come In?

For archaeologists working in tropical regions, the aquaculture-civilization hypothesis provides a new interpretive framework for understanding sites with water management infrastructure. Re-examining known canal systems, raised fields, and reservoir complexes through an aquacultural lens — specifically looking for evidence of fish management and aquatic resource harvesting — could reveal previously unrecognized dimensions of ancient subsistence strategies.

For environmental scientists and ecologists, ancient aquaculture systems represent long-duration experiments in landscape-scale water and ecosystem management. Understanding how these systems functioned, how productive they were, and whether they were sustainable provides data relevant to contemporary debates about aquaculture, wetland management, and food security in tropical environments.

For food security researchers and development practitioners, the ancient evidence challenges the assumption that intensive agriculture must follow the grain-monoculture model. The integrated agro-aquacultural systems of the Casarabe and Maya demonstrate alternative approaches to food production that may be more appropriate for tropical wetland environments than introduced temperate-zone agricultural practices.

For the interested public, the story of fish farming civilizations upends conventional narratives about the origins of complex societies. The idea that some of the world's great civilizations were built not on wheat fields but on fish ponds challenges assumptions about what "civilization" requires and opens a more diverse, more ecologically grounded understanding of human cultural achievement.