A study just published in PLOS One sheds new light on the Calusa tribe of southern Florida and how they used their discards. A hunter-gatherer tribe who subsisted primarily on seafood, the Calusa used the discarded shells from shellfish to form habitable islands.
Mound Key was the capital of the South Florida Calusa when the Spanish first interacted with them in the 1500s. Thompson et al. ran a series of radiocarbon dating tests on the midden (or discarded trash) on Mound Key and discovered that the island was deliberately formed and shaped from discarded shells and bones, an early form of landscape engineering.
Reference:
Victor D. Thompson, William H. Marquardt, Alexander Cherkinsky, Amanda D. Roberts Thompson, Karen J. Walker, Lee A. Newsom, Michael Savarese. From Shell Midden to Midden-Mound: The Geoarchaeology of Mound Key, an Anthropogenic Island in Southwest Florida, USA. PLOS ONE, 2016; 11 (4): e0154611 DOI: 10.1371/journal.pone.0154611