Anthropology Theses and Dissertations

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Browsing Anthropology Theses and Dissertations by Author "Ainis, Amira"

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    Reconstructing Nearshore and Kelp Forest Habitats from Trans-Holocene Occupations at Bay Point, San Miguel Island, California: The Archaeology and Historical Ecology of Daisy Cave and Cave of the Chimneys
    (University of Oregon, 2019-09-18) Ainis, Amira; Erlandson, Jon
    This dissertation examines the archaeology and historical ecology of Bay Point, San Miguel Island, California. Using archaeological datasets from Daisy Cave and Cave of Chimneys, I focus on the role of primary producers (Macrophytes) and primary consumers (i.e., sea urchins) in structuring near-shore marine ecosystems over a 10,000-year period. I argue that it is essential in historical ecological reconstructions of marine environments to examine local ecosystems from the lower trophic levels up, although this approach is often challenging in archaeological contexts as kelp and other marine algae seldom survive in the archaeological record, leaving an important data source silent in most coastal and island archaeological accounts. To overcome these limitations and get as close to seaweeds and sea grasses as possible, I developed two methods to examine ancient kelp forest and rocky shore ecosystems. In one case, I used seaweed and sea grass shellfish commensals found at Cave of the Chimneys as a proxy for studying ancient kelp and surf grass ecosystems. These shellfish provide a wealth of untapped data about kelp forest ecology, and because of their durability, can be analyzed from a variety of archaeological contexts through time. At Bay Point, I show that humans were directly harvesting kelp and sea grass and transporting them to base camps for processing, consumption, and use. Another case study focuses on sea urchins, which feed on giant kelp and, if left unchecked, can wipe out entire forests. For this study, I developed a regression formula to determine sea urchin size based on hemipyramid morphometrics. This method allowed me to examine changes in the abundance and size of sea urchins through time, providing additional proxy data for understanding changes in kelp systems. Recognizing that ocean geochemistry plays an essential role in determining whether kelp can grow and thrive, it is necessary to construct local temperature curves to provide an overall environmental context for my study. To address this, I analyze stable isotopes (แตน13C and แตน18O) from archaeological mussel shells spanning most of the Holocene to construct a local nearshore sea surface temperature (SST) sequence and explore correlations between ancient SST patterns and the archaeological data at Bay Point. My dissertation contributes to a growing database of coastal historical and ecological studies that help decipher the complex nature of intertidal foraging and marine fishing over the course of human history and across the globe. By providing new methods of analysis, a fresh bottom up perspective, and primary zooarchaeological and archaeometric data on some of the oldest, most intact, and best-preserved archaeological sequences on the Channel Islands, my dissertation also contributes to broad anthropological and paleoenvironmental research questions for the region and beyond. It provides datasets and interpretations fundamental for addressing long-standing questions about the nature and antiquity of aquatic resource use, shifts in harvesting practices and human impacts to marine ecosystems, the perceived marginality of island environments, mobility, settlement, and land use patterns, as well as other topics of transdisciplinary interest. As the first long-term reconstructed nearshore SST sequence for the region, the results have significant implications for a variety of local research questions in archaeology, historical ecology, paleoecology, marine biology, oceanography, conservation biology, and fisheries management.