Stable Isotope Study of Hunter-Gatherer-Fisher Diet, Mobility, and Intensification on the Texas Gulf Coastal Plain

The Gulf Coastal Plain of Texas was populated by hunter-gatherers from the Early Archaic (ca. 7000 B.P.) through to the Late Prehistoric period (ca. A.D. 700-1400). In order to characterize past dietary adaptations along the coast and further inland, stable isotopes of carbon and nitrogen were analyzed in preserved bone from 198 individuals from mortuary sites. In addition, 140 samples of faunal bone were analyzed to elucidate the stable isotope ecology for each region. The results indicate long-term stability in dietary adaptations with regional variation among coastal, riverine, and inland groups, including an early and, substantial, use of freshwater and marine resources. There is also evidence for constrained mobility and increasing use of plant resources within regions as populations increased in size and density.