Ancient DNA investigation of prehistoric salmon resource utilization at Keatley Creek, British Columbia, Canada

Abstract

This study applied ancient DNA techniques to achieve accurate species identifications for the archaeological salmon remains recovered from the prehistoric pithouse village of Keatley Creek in British Columbia, Canada. Previous archaeological studies indicate that economic stratification within the community might have resulted in differential access to some preferred salmon species, such as sockeye and chinook. Unambiguous ancient DNA species identification now makes it possible to more accurately address the issue of early salmon resource utilization in the region. This study analyzed 60 salmon remains from two specialized structures and two residential structures in order to identify any species differences among bony salmon remains found within the structure. Although high success rates (over 90%) were obtained for ancient DNA tests, only three species (chinook, sockeye and coho salmon) were identified from the remains. Pink salmon was not identified among the tested sample, despite the fact that it was originally assumed to be a staple species for the site's native inhabitants. The absence of pink salmon in our sample significantly altered the picture of early salmon fishing activities in the region. As a result, the effects of economic stratification on differential access to the remaining so-called preferred species of sockeye and chinook within the four structures studied were not as dramatic as previously thought, although differences among the structures could still be observed.