An enormous fish-trapping system was constructed by the ancient Central Americans.
Earthen channels directed fish into ponds that formed seasonally, providing a dietary bounty for Maya civilizations starting around 4,000 years ago.
prativad 
According to a recent study, a complex fish-trapping system in lowland Central America began to sustain growing human populations around 4,000 years ago. This enormous construction project's finding suggests that aquatic foods contributed to the development of Maya civilization approximately a thousand years later.
Archaeologist Eleanor Harrison-Buck of the University of New Hampshire in Durham and her colleagues claim that an ancient system of earthen channels that zigzag across wetlands in what is now the country of Belize directed fish and other aquatic edibles into ponds that formed as flood waters receded in the spring and early summer. The researchers conclude November 22 in Science Advances that fish caught in those ponds could have provided food for an average of almost 15,000 people each year.
That many people probably did not assemble near the fish traps until the emergence of large Maya ceremonial and urban centers around 3,000 years ago, the scientists say (SN: 6/3/20).
Harrison-Buck’s team used a camera-mounted drone and Google Earth images to detect 167 shallow channels covering nearly 42 square kilometers in Belize’s Crooked Tree Wildlife Sanctuary. Mapped during the height of the summer dry season in 2017, nearly 60 ponds appeared near the crisscrossing channels.
Radiocarbon dating of material from three excavated channels indicates that hunter-gatherers initially constructed the fish-trapping setup around 4,000 years ago. Geological signs of a drought from about 4,200 to 3,900 years ago indicate that the area turned from a year-round to seasonal marshland at that time, spurring a dietary shift from cultivated maize to aquatic foods (SN: 12/13/18).
No signs of maize pollen turned up in the channel excavations. Ancient menus in this region included fish, turtles, mollusks, waterfowl and edible seeds of amaranth plants that grow well on open landscapes during droughts, the scientists suspect.
According to the experts, Maya peasants enjoyed the aquatic richness of the fish-trap system between 3,200 and 1,800 years ago. One conduit that was unearthed led directly to Chau Hiix, a significant Maya center.
In the vicinity of the fish-trapping system, future fieldwork will search for the remnants of pre-Maya settlements. Additionally, the researchers will look at potential canal networks that were discovered at two additional wetlands in Belize and one in southern Mexico using remote sensing.
