Évaluation génétique pour la discrimination des stocks de bélugas dans la baie Cumberland

Abstract

Beluga whales in Cumberland Sound are harvested by hunters from the hamlet of Pangnirtung. Assessments in 2016 and 2019 indicated the current harvest is not sustainable. Harvest changes have not been implemented, in part, because there are questions regarding the number of beluga whale populations that inhabit Cumberland Sound. Genetic variation among beluga whales harvested in Cumberland Sound was assessed against samples from other Canadian populations using DNA inherited from both parents and from mothers only. Genetic analyses revealed that there is a distinct population specific to Cumberland Sound, hereafter identified as the Cumberland Sound Beluga (CSB) population. Whales harvested in Cumberland Sound comprise two populations. Of the 27 samples evaluated from DNA inherited from both parents, the majority were from the CSB population (74%). The remainder (26%) were most similar to whales from the Western Hudson Bay (WHB) population. It is unknown whether whales most similar to WHB were temporary or permanent migrants in Cumberland Sound. The frequency of possible migration is also unknown. Because these two populations cannot be distinguished visually during abundance surveys, management should recognize that the distinct CSB population is likely smaller than previously estimated. Future genetic assessments of beluga in Cumberland Sound would benefit from including DNA inherited from both parents.