Genomic population structure of Eastern Canadian Arctic and St. Lawrence beluga. Delphinapterus leucas

In Canada, commercial harvest of belugas (Delphinapterus leucas) between the 19th and 20th century has considerably reduced population sizes in the low Eastern Canadian Arctic. This severe depletion of individuals makes some populations susceptible to extinction, affecting northern communities relying on the presence of belugas for both cultural and nutritional values. Historically, management of belugas summering in this area has been based on genetic differences between Eastern and Western Hudson bay belugas, identifiable using mitochondrial DNA sequences. To fine-tune conservation management of the evolutionary units of belugas summering in the low Eastern Canadian Arctic, this study used samples from individuals harvested between 1982 and 2021. Samples were genotyped for genome-wide single nuclear polymorphisms (SNPs) using both double-digest RAD sequencing (ddRAD, N= 639, SNPs=27,352) and low coverage whole genome sequencing (lcWGS, N = 341, SNPs = 845,731) to infer genetic clusters, admixture proportions and the amount of differentiation among clusters.