Genomic structure of Canadian polar cod (Boreogadus saida)

The polar cod Boreogadus is an abundant and ubiquitous member of the Arctic adapted to high latitude conditions and acting as a critical link in oceanic foodwebs. Knowledge on population structure in Boreogadus therefore provides a key foundation for better understanding the adaptive potential of this species and, by extension, Arctic oceanic ecosystems under climate change. Here, we present the first genome wide survey of population structure in Boreogadus, focusing on Canadian populations. Using restriction site associated loci, we genotyped a total of 38,131 SNPs in 507 individuals sampled from the West Arctic to the Gulf of Saint Lawrence marine ecoregions, and infer population structure using a combination of PCA, DAPC, and ADMIXTURE analyses.