Doctoral Dissertation Research Award: The Effect Of Long Term Environmental Variation On Human Adaptation

University Of Oregon Eugene, Eugene OR

Investigators

Abstract

This project investigates dynamic long-term interactions between California Channel Island foragers and the marine ecosystems that sustained them. It will examine trends in nearshore paleooceanographic conditions, human marine resource use, and technological innovation over the past 10,000 years. Erlandson and Ainis will examine trends in the lifeways of maritime people of the Pacific Coast of North America through archaeological, stable isotope, and statistical analyses of cultural deposits from two adjacent rockshelter sites occupied sequentially by the Island Chumash and their ancestors over the past 13,000 years. Colonized at least that long ago by seafaring Paleoindians, Channel Island shell middens have played an important role in the emergence of theories such as the coastal migration hypothsis as a viable explanation for the initial peopling of the Americas. Archaeological remains reveal how islanders interacted with and utilized terrestrial and marine ecosystems for thousands of years, providing pertinent data for modern conservation and management programs that are often constrained by relatively recent and short-term baseline data. Stable isotope analysis of marine mollusks is a proven method for reconstructing oceanographic conditions and identifying the seasonality of shellfish harvest, data useful for reconstructing settlement patterns and nearshore paleoecology. These data will be used to construct a site-specific nearshore sequence for San Miguel Island and explore correlations between ancient sea surface temperature (SST) patterns and archaeological data. This study will contribute to larger research questions related to the antiquity and diversity of aquatic resource use, shifts in resource harvesting practices and human impacts on marine ecosystems, the perceived marginality of island environments, mobility patterns, seasonality of site occupations of some of the earliest maritime people of the Pacific Coast. As the first long-term reconstructed nearshore SST sequence for the region, the results will have significant implications for a variety of research questions in archaeology, historical ecology, paleoecology, marine biology, oceanography, conservation biology, and fisheries management. The project will also provide opportunities for student training in faunal and archaeometric analyses through the University of Oregon's Island and Coastal Archaeology Laboratory. Stable oxygen and carbon analysis of ~120 marine mollusk shells from 12 chronologically discrete components from three sites located within a ~300 m stretch of coastline on San Miguel Island will be used to determine season of harvest data and reconstruct the longest nearshore SST sequence for the region. SST data will be statistically correlated with relative proportions and sizes of dominant shellfish species from each archaeological component, taking into account species-specific biological and ecological information for all taxa, and small-scale local paleo-oceanographic conditions. Research that uses stable isotope analysis of marine shells, detailed zooarchaeological analysis, and statistical measures will allow strong inferences about ecological changes and the adaptive shifts of coastal foragers by providing a proxy for small-scale oceanographic variability in nearshore habitats where human harvesting was occurring. These data will contribute to a growing database that helps archaeologists decipher the complex nature of intertidal foraging, marine fishing and hunting, human mobility, and technological change on the Channel Islands during ~13,000 years of human habitation.