Effects of environmental variation on stable isotope analyses in Waya Island, Fiji

Abstract

In Pacific archaeology, there is a question of how people adapted to island ecologies and how this changed over space and time. Environmental variation may have affected the diets and mobility patterns of prehistoric peoples and changed how they interacted with their environments, and these effects may be enhanced on smaller islands. Stable isotope analyses are used in bioarchaeology to study life histories of people in the past, and comparisons can be made with ecological samples to show the local environment. The aims of this thesis were to study the value of using stable isotopes on materials from a small island in Remote Oceania and to study how environmental variation affects our understanding of life histories. To study these aims, human and faunal materials were analysed from Waya Island, a small island in Fiji. There were four humans analysed in this thesis from two different sites. Faunal material included three pigs, a bird, a turtle, and 30 fish bones representing 11 families. Strontium isotopes can show mobility during childhood when tooth enamel was developing by comparing with geochemical and environmental strontium values. Significant variation in these values can be caused by sea-spray and marine-based diets. Carbon and nitrogen isotopes show the proportion of marine, terrestrial, plant, and animal sources in the diet. Variations in these values can exist over space and time, and local baseline data is needed to show the island context. The results showed a small range of strontium values that is not indicative of mobility between these individuals and is possibly linked to the geological homogeneity of the small island. Other studies had much larger ranges showing the heterogeneity in local environments, which may limit the identification of non-locals. The human dietary isotope values were mostly consistent with previously analysed Waya Islanders. The faunal data showed significant variation compared to other values across the Pacific. This has implications for our understanding of dietary habits and how people used their local environments. This study has shown the importance of using local data to create site-specific baselines to provide more detailed life histories in Remote Oceania. Keywords: stable isotopes, strontium, carbon, nitrogen, Remote Oceania, environmental variation, Fiji.