Caption: Modern day fishing continues in the wetland lagoons of the Crooked Tree Wildlife Sanctuary (CTWS). Credit:  Courtesy Belize River East Archaeology (BREA) Project.

Wetland investigations uncover network of pre-Columbian linear fish-trapping channels and ponds in the Mayan lowlands of Belize.

An archaeologist from the University of New Hampshire and her team have collected data which indicates the presence of a large-scale pre-Columbian (the Americas before the arrival of Christopher Columbus in 1492) fish-trapping facility.

Discovered in the Crooked Tree Wildlife Sanctuary (CTWS), the largest inland wetland in Belize, the team dated the construction of these fisheries to the Late Archaic period (cal. 2000-1900 BCE), pre-dating Amazonian examples by a thousand years or more.

Eleanor Harrison-Buck, professor of anthropology and director of the Belize River East Archaeology (BREA) project, said: “The network of canals was designed to channel annual flood waters into source ponds for fish trapping and would have yielded enough fish to feed as many as 15,000 people year-round, conservatively.

“The dates indicate that the fisheries were initially constructed by Late Archaic hunter-gatherer-fishers and continued to be used by their Formative Maya descendants (approximately 2000 BCE to 200 CE).

“For Mesoamerica in general, we tend to regard agricultural production as the engine of civilisation, but this study tells us that it wasn’t just agriculture – it was also potential mass harvesting of aquatic species.”

Researchers doing reconnaissance in the Crooked Tree Wildlife Sanctuary (CTWS) where they discovered evidence of a large-scale pre-Columbian fish-trapping facility. Credit: Courtesy Belize River East Archaeology (BREA) Project.

Long-term climate disturbance

The research used 26 radiocarbon dates from test excavation sites in the CTWS, which indicate that such landscape-scale wetland enhancements may have been an adaptive response to long-term climate disturbance recorded in Mesoamerica between 2200 and 1900 BCE.

Harrison-Buck said: “The early dates for the canals surprised us initially because we all assumed these massive constructions were built by the ancient Maya living in the nearby city centres.

“However, after running numerous radiocarbon dates, it became clear they were built much earlier.”

Sediment samples were collected along the walls of the excavation units and sequenced for specific elements, such as nitrogen and carbon, to look for environmental changes over time.

The sediment showed a strong tropical forest dominance during that period and no evidence of crop cultivation, specifically maize.

Along with a lack of any pollen from domesticated crops, there weren’t any signs of ditched and drained agricultural fields in the immediate area dating to that time.

The multiproxy data gathered suggests the distinctive long linear zigzag channels served primarily as large-scale fish-trapping facilities.

Annual fish harvests

BREA co-director Marieka Brouwer Burg, professor of anthropology at the University of Vermont, said: “It seems likely that the canals allowed for annual fish harvests and social gatherings, which would have encouraged people to return to this area year after year and congregate for longer periods of time.

“Such intensive investments in the landscape may have led ultimately to the development of the complex society characteristic of the pre-Columbian Maya civilisation, which subsequently occurred in this area by around 1200 BCE.”

Samantha Krause, professor of geography and environmental studies at Texas State University, added: “Wetlands have always been a critical ecosystem for humans across the globe. Knowing how to manage wetland resources responsibly is essential for the continued resilience of these ecosystems both in the past and today.

“The Archaic hunter-gatherer-fishers knew how to protect their resources and use them in a way that could sustain these habitats, not exhaust them, which explains their long-lasting occupation in this area.”

With the support of the local community, the team plans to return to Crooked Tree to investigate a larger sample of these landscape-scale modifications that they have identified across a broad area of northern Belize, hoping to more fully understand the complexity of human-wetland interactions in the past.

The research is published in Science Advances.