Thursday, May 8, 2014 - 20:00

An open pit exposes a 3,200-year-old shell midden. Native Americans used middens as trash piles for oyster shells, animal bones and pottery. Image: Torben Rick, Smithsonian.

The eating habits of people who lived in the Chesapeake Bay area thousands of years ago spawned a rich variety of plant life that can still be seen in the region’s forests today.

   That’s what researchers from the Smithsonian Environmental Research Center found after burrowing into nutrient-heavy areas of woodlands and finding trash piles loaded with shellfish remains.
   Ancient tribes roamed the Chesapeake Bay area more than 13,000 years before Europeans arrived. During what is called the Woodland period --3,200 to 400 years ago -- they ate oysters and other shellfish, tossing the shells into piles.
   Native Americans also dumped animal bones and pottery on the trash heap. Archeologists call mounds of shells, animal bones and other trash from early settlements “middens.”
   Along the Chesapeake shoreline, “These middens look like patches of grasses and flowers scattered throughout the forest,” said Susan Cook-Patton, lead author of the study and postdoctoral fellow at the Environmental Research Center. “It isn’t until you dig through the soil and find shell fragments that you realize that you are looking at the remains of a meal eaten hundreds to thousands of years ago.”
   Cook-Patton and the other researchers, including some from Cornell University, looked at 10 midden sites along the Rhode River on the research center’s campus in Edgewater, Maryland.
   Some sites were roughly 200 years old. Others were up to 3,250 years old. The researchers compared nutrients in soil samples from middens with the components of other soil samples nearby.
   Soils from the middens showed almost 45 times more calcium and 6.7 times more nitrate than was present in other soils. The midden soils also fostered a more diverse array of plants: There were 29 species that grew only in the middens, compared with nine species that grew only on nonmidden sites.
   “This work is an important contribution to our understanding of how humans can influence their environments over centuries, millennia or more,” said Torben Rick, anthropologist at the Smithsonian’s National Museum of Natural History and a co-author of the paper, published April 24 in Landscape Ecology. “It also demonstrates the value of interdisciplinary research, in this case the integration of terrestrial ecology, botany and archaeology.”

Taken from a Smithsonian Institution press release.