Gulf of Alaska | Seabirds
An inter-disciplinary approach to studying seabird ecology and their role in Unangan lifeways Presenter: Nicole Misarti, nmisarti@alaska.edu, University of Alaska Fairbanks Miranda Lazar , mirandalazar@arizona.edu, University of Arizona
Joshua Reuther , jreuther@alaska.edu, University of Alaska Museum of the North Scott Shirar , sjshirar@alaska.edu, University of Alaska Museum of the North Liza Mack , lmack@denali.gov, Denali Commission
Long-term ecosystem research is crucial to understanding environmental and anthropogenic processes that impact marine food webs in the Aleutian Islands, AK. Seabird bones recovered from archaeological middens can provide ecosystem baseline data on a large temporal scale. Additionally, seabirds have been, and continue to be, an important resource for Unangax̂ communities. Seabirds were hunted for subsistence, raw material for everyday items (e.g., clothing and bone tools), and magical/ transformative processes. Sanak Island, the eastern most island in the Aleutian chain, offers a unique opportunity to study the cultural and ecological relationship between the Unangan and seabirds, as the archaeological excavations have yielded over 17,000 bird bones that span ~4000 years of occupation on the island. Here, we examine how temporal changes in environmental conditions may be impacting seabird foraging locations and trophic position, and subsequently, human hunting strategies and landscape use. To do this, we use zooarchaeological data, such as the Number of Identified Specimens (NISP) quantification measure, and stable isotope analysis of δ13C and δ15N in bone collagen from the Sanak Island Archaeological Collection. Taxa in this study include guillemot ( Cepphus ), murre ( Uria ), puffin ( Fratercula ), cormorant ( Phalacrocorax ), diving ducks ( Aythinae ), auklet ( Aethia ), murrelet ( Brachyramphus ), and albatross ( Diomedeidae ). Cormorants were the most numerous seabirds (NISP= 2038) recovered from archaeological sites on Sanak, followed by murres (NISP= 995), while diving ducks (NISP= 97) and guillemots (NISP= 39) were the least abundant in the collection. Preliminary stable isotope data for archaeological cormorant specimens show significant changes between warm and cold climate periods in δ15N (T-test, p<0.001) but not δ13C (T-test, p=0.7163), suggesting that cormorants targeted different prey types but did not change foraging locations. This retrospective study can inform modern seabird management decisions and serves as a springboard for future long-term ecosystem studies using compound-specific stable isotope analysis (CSIA-AA). Lastly, it provides an ecological backdrop to further investigate the relationship between seabirds and the Unangax̂ .
Alaska Marine Science Symposium 2023 233
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