Historical Ecology and Biogeography of North Pacific Pinnipeds: Isotopes and Ancient DNA from Three Archaeological Assemblages

Abstract

ABSTRACT Zooarchaeology has the potential to make significant contributions to knowledge of pinniped biogeography of import to both archaeologists and environmental scientists. We analyzed northern fur seal remains found in three archaeological sites located along the outer coast of the Northeast Pacific Ocean: Cape Addington Rockshelter in southeast Alaska, Ts’ishaa on the west coast of Vancouver Island, and the Netarts Sandspit site on the Oregon Coast. These three sites occur along an 850 km stretch of coastline between 45° to 55° N. and 123° to 134° W., far southeast of the primary breeding area for northern fur seals today, located on the Pribilof Islands at 57° N. 170° W. We use ancient DNA (aDNA) and carbon (δ13C) and nitrogen (δ15N) isotopes to investigate whether northern fur seal remains from these archaeological sites originated with migratory Pribilof Islands populations. For sites located in Oregon and points north, the isotope values are not distinct from those of the Pribilof fur seals. Although aDNA was recovered from three pinniped species (northern fur seal, Steller sea lion, and Guadalupe fur seal), the paucity of published genetic data from modern northern fur seals prevents us from distinguishing the archaeological specimens from modern Pribilof seals.