Reconstructing Holocene Kelp Ecosystems through Stable Isotope Analysis of Archaeological Shell Material
We have initiated a two-phase project that involves analysis of shell material from recent and Holocene communities to assess the utility of this method. Phase I involved collection of shell material from different species of marine grazers (Strongylocentrotus, Tegula) and sessile filter-feeders (Mytilus) from coastal sites in central California with and without kelp. The stable isotope composition of the organic matrix extracted from these shells was then analyzed to identify isotopic markers for kelp and other marine algae. Results from this project will be carried over to Phase II using shell material from collected from a nearly complete trans-Holocene (10,000 calendar years BP to ca. AD 1820) record of shell remains from San Miguel Island. The stable isotope composition of these remains will be used to reconstruct changes in the diets of these consumers over time and establish whether sampled consumers lived in forested or deforested habitats.