The Maya formed a prime relationship with wetlands, but the dynamic of Maya engagement varied by place and time largely due to environmental change. Ground truthing each locale remains essential.

We and our research team have conducted archaeological investigations along the lower courses of the Hondo and New Rivers of northern Belize (Pohl et al. 1996). The key to our project’s success lies in our geoarchaeological strategy of combining paleoecological coring with excavation pits extending below the water level using a sophisticated pumping system. The pits have filled in data on material culture extending far back into the Preclassic and Archaic periods and have yielded valuable organic remains for radiocarbon dating.    

Map of our coring and excavation locations marked by red dots.

We recovered robust evidence for Archaic and Preclassic period human activity at every excavation location we tested:

  • Pulltrouser Swamp, Turner and Harrison’s (1983) Site 1 (N 18.1322 W 88.5514) on the New River
  • San Antonio, Santa Cruz, and Lagarto on Albion Island in the Hondo River
  • Douglas, Pat, and Cob Swamps further downstream on the Hondo River

We cored wetlands adjacent to our excavations at Pulltrouser Swamp and at Cob Swamp. The northern Belize coring transect continued in wetlands at San Maximo and Santa Rosa, as well as offshore at Consejo and in Corozal Bay in front of the archaeological site of Cerro Maya.

Area stratigraphy illustrated at Douglas Swamp. 

The top of the gray Archaic period level is exposed in the pit floor. Preclassic organic black soils follow with ditch visible in left corner of the unit.

The white lens in the organic level records local flooding.

The Classic period brown soil horizon above represents a widespread erosional phenomenon termed “Maya Clay.”

The surface topography with what appeared to be constructed mounded platforms and canals was instead found to be the natural result of secondary deposition of gypsum heaving land upward during the Terminal Classic megadrought.

(photo by Ken Garrett) 

When agriculture first appeared in northern Belize remains an open question. Paleoecological data, including pollen, have inherent weaknesses in identifying the onset of cultivation. Palynologist John Jones identified a small, archaic type of domesticated maize appearing about 3400 BCE at Cob Swamp. Our pollen diagram for Pulltrouser Swamp shows forest disturbance as early as about 5000 BCE but without definitive evidence for cultigens.

Small, archaic domesticated maize pollen in the process of evolution
(photo by John Jones)

We speculate that migration played a role in changes in subsistence as documented in southern Belize (Kennett et al. 2022).  Genetic evidence from burials points to a south to north migration from Central and northern South America sometime between about 5300 BCE and 3600 BCE. Chibchan speaking migrants likely brought maize they had genetically modified (Kistler et al. 2018). This in-migration phenomenon may have impacted indigenous populations living along the Hondo and New rivers of northern Belize during this same time frame.  

Our cores recorded a dramatic expansion of human activity after about 2500 BCE. Pollen markers include a sharp decline in forest taxa such as Moraceae, charcoal from burning, appearance of weedy species, and cultigens including both maize and manioc.

The onset of drought conditions apparent in our stratigraphy, especially after 2200 BCE, would have influenced food strategies, especially in wetlands. Rich organic soils that originally formed along river margins and in karst depressions in response to late Holocene sea level rise were exposed as groundwater levels fell, providing an attractive resource for farmers. The Maya initially cultivated their crops on the wetland margins in the Late Archaic to Early Preclassic periods. Only much later did we identify evidence of ditching when water levels began to rise.

Cob Swamp pollen diagram showing expansion of maize farming after ca. 2500 BCE 
(John Jones, palynologist)

Water levels continued to rise due to sea level change, and by the Classic Period the wetlands along the lower courses of the Hondo and New rivers were mostly flooded. Near the end of the Classic Period a layer of sediment, often referred to as “Maya Clay” and resulting from soil mismanagement and erosion, filled the river margins and karst depressions. This Maya Clay, and the underlying Preclassic organic soils, are riddled with secondary gypsum, which precipitated in situ from sulfate-rich groundwater, confirming that the precipitation occurred after the Maya Clay was deposited. For this to happen, water levels had to have dropped significantly, exposing the sediments and organic soils to seasonal drying, an event we correlate with the Terminal Classic megadrought. 

None of our excavations produced evidence of wetland field construction.  Preclassic period ditching of the organic soils was detected in a few locations, at Douglas, San Antonio, Lagarto, and to a lesser extent Cob and possibly Pat, probably in response to rising groundwater. Our trenches into what appeared at the surface to be raised platforms and adjacent canals (including at Pulltrouser Swamp) turned out to be natural features created by in situ gypsum precipitation that expanded the volume of the soil more than 50%, heaving the surface upward and leaving troughs between heaved sections. The high levels of gypsum in these soils precluded maize cultivation.

In sum, the Maya pioneered wetland agriculture along the lower courses of rivers in northern Belize. Faced with environmental challenges, they attempted to rescue their fields from flooding with ditching beginning in the Late Preclassic period. The Maya eventually abandoned most wetland fields here by the Classic Period when natural processes of flooding and drought created an unstable environment. It is possible, even likely, that much of the patterned ground found today in Maya wetlands where groundwater has high concentrations of sulfate is a result of the Maya megadrought rather than Maya wetland engineering.

Videos of the excavations

Geoarchaeologist Kevin Pope and soil scientist John Jacob discuss stratigraphy. Videos include the work of paleoethnobotanist David Lentz, palynologist John Jones, and marine geologist John Gifford. Pulltrouser Swamp  Douglas East Belize Vibracoring

Cited references

Kennett, Douglas J., Mark Lipson, Keith M. Prufer, David Mora-Marín, Richard J. George, Nadin Rohland, Mark Robinson, Willa R. Trask, Heather H. J. Edgar, Ethan C. Hill, Erin E. Ray, Paige Lynch, Emily Moes, Lexi O’Donnell, Thomas K. Harper, Emily J. Kate, Josue Ramos, John Morris, Said M. Gutierrez, Timothy M. Ryan, Brendan J. Culleton, Jaime J. Awe, and David Reich
 2022    South-to-north migration preceded the advent of intensive farming in the Maya region. Nature Communications 13(1):1530. DOI:10.1038/s41467-022-29158-y.

Kistler, Logan, S. Yoshi Maezumi, Jonas Gregorio de Souza, Natalia A. S. Przelomska, Flaviane Malaquias Costa, Oliver Smith, Hope Loiselle, Jazmín Ramos-Madrigal, Nathan Wales, Eduardo Rivail Ribeiro, Ryan R. Morrison, Claudia Grimaldo, Andre P. Prous, Bernardo Arriaza, M. Thomas P. Gilbert, Fabio de Oliveira Freitas, and Robin G. Allaby
 2018    Multiproxy evidence highlights a complex evolutionary legacy of maize in South America. Science 362(6420):1309–1313. DOI:10.1126/science.aav0207.

Pohl, Mary E. D., Kevin O. Pope, John G. Jones, John S. Jacob, Dolores R. Piperno, Susan D. deFrance, David L. Lentz, John A. Gifford, Maria E. Danforth, and J. Kathryn Josserand
 1996    Early Agriculture in the Maya Lowlands. Latin American Antiquity 7(4):372. DOI:10/d83tks.

Turner, B.L. II and Peter D. Harrison, eds.
1983 Pulltrouser Swamp. Ancient Maya habitat, agriculture, and settlement in northern Belize.  University of Texas Press, Austin.

3 thoughts on “Wetlands of Lower New and Hondo Rivers, Belize, with Pulltrouser Swamp

  1. Yes, thanks for an informative and thought-provoking essay. If you have maize in Belize at these dates, why hasn’t it cropped up at San Lorenzo a millennium later?


    1. Weaknesses exist in the use of data such as pollen, macrobotanicals, phytoliths and the like to draw timelines for the appearance of domesticated plants, specifically maize. The evidence from any one location or area might be incomplete due to the vagaries of deposition of paleobotanical remains in the archaeological record.

      The convergence of different types of data remains ideal. Our coring program around the Middle Formative Gulf Coast Olmec site of La Venta and its subsidiary San Andrés documented maize ca. 3500 BCE. Note that the presence of both phytoliths and pollen, along with disturbance indicators in the pollen record, strengthens the placement of the appearance of maize around this time horizon. The earliest maize pollen was the same small, archaic type as that found in northern Belize.

      References for further reading:

      Pohl, Mary E. D., Dolores R. Piperno, Kevin O. Pope, and John G. Jones
      2007 Microfossil evidence for pre-Columbian maize dispersals in the neotropics from San Andrés, Tabasco, Mexico. Proceedings of the National Academy of Sciences 104(16):6870–6875.

      Pope, Kevin O., Mary E. D. Pohl, John G. Jones, David L. Lentz, Christopher Von Nagy, Francisco J. Vega, and Irvy R. Quitmyer
      2001 Origin and environmental setting of ancient agriculture in the lowlands of Mesoamerica. Science 292 (5520):1370–1373.


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