Ariana B. J. Lambrides

Late Holocene Marshall Islands Archaeological Tuna Records Provide Proxy Evidence for ENSO Variability in the Western and Central Pacific Ocean

ABSTRACT Tuna will have increased importance to Pacific Island nations in coming decades for food security and economic needs; consequently, sustainable fisheries management policies are imperative. The frequency and temporal distribution of tuna bones from tropical Pacific archaeological sites is essential for documenting millennial-scale records that detail the responses of tuna stocks to anthropogenic fishing pressure and climatic variability. We highlight the potential impacts of El Niño-Southern Oscillation (ENSO) variability on the western and central Pacific Ocean skipjack (Katsuwonus pelamis) fishery over the last 2,000 years. Ebon Atoll (4°38′24.67″N, 168°42′23.56″E), Republic of the Marshall Islands archaeological data and regional western and central Pacific Islands archaeological tuna fishery data are evaluated. These datasets are compared to palaeoclimate records, which track hydroclimate variability during the last 2,000 years, and recent historic capture records, which document associations between ENSO and skipjack abundance and range throughout the tropical Pacific Ocean. Results suggest that regional and temporal trends in archaeological scombrid/skipjack abundance provide proxy evidence for western and central Pacific Ocean ENSO variability, while prehistoric human impacts to the tuna fishery appear to be negligible. Future research should include species-level identification of all archaeological tuna bones and establish fine-grained local climate data across the region that is tied to well-dated archaeological sequences, thus enhancing our understanding of how regional climate influences the geographic distribution and relative abundance of tuna species over millennia.

Sustained prehistoric exploitation of a Marshall Islands fishery: ichthyoarchaeological approaches, marine resource use, and human-environment interactions on Ebon Atoll

i Declaration by author iii Publications during candidature iv Publications included in this thesis iv Contributions by others to the thesis vii Statement of parts of the thesis submitted to qualify for the award of another degree vii Acknowledgements viii