Sex-Biased Harvest of Chinook Salmon at Babine Lake? Ancient DNA Evidence from Archaeological Vertebrae

Abstract

Located in north-central British Columbia, Smokehouse Island at Babine Lake is an ancient fishery site used by the ancestral Nedut’en (Lake Babine Nation) approximately 1,000 years ago. Previous aDNA research at this site identified sex-selective harvesting of male sockeye salmon, a practice linked to sustainable resource management. In contrast, a female bias was observed among a small sample of Chinook salmon remains (8 samples), raising an important question: was sex-selective fishing intentionally applied to female Chinook salmon at Smokehouse Island, or was the initial sample size simply too small?  

This study aims to address this question through analysis of 22 additional Chinook salmon vertebrae from the same site. Species identification will be confirmed through DNA sequence analysis, and sex will be determined by amplification of a nuclear Y-chromosome marker. The first subset of 6 additional samples analyzed in this study indicated a similar female-biased sex ratio observed previously. If this pattern persists once all 30 samples are combined and analyzed, sampling bias may be excluded, supporting the interpretation of intentional, egg-targeted harvesting from female Chinook salmon, the largest salmon species with the highest yield of eggs per individual.  

This study aims to further highlights the power of ancient DNA analysis for species and sex identification of archaeological salmon remains. The genetic information obtained from this analysis allows for more precise reconstructions of fishery practices and resource management strategies developed by Indigenous peoples in the region.