Conservation genetics of the St. Lawrence beluga whale (Delphinapterus leucas)

Abstract

Beluga whales (<i>Delphinapterus leucas</i>) migrated to the St. Lawrence Estuary near the end of the Holocene glacial retreat, when dry land emerged. The population currently inhabiting the St. Lawrence shows strong site fidelity, which is generally common with belugas. Decades after a ban on the hunting of the beluga whale in 1979, the lack of recovery noticed in the St. Lawrence Estuary (SLE) population has puzzled researchers who study beluga whales. The St. Lawrence Estuary has been known for its industrialization, as well as its large amounts of vessel traffic, contributing to entanglements, as well as pollution to the river and its inhabitants. The current population of belugas inhabiting the SLE are ~1000 or less, and are declining, which is concerning because the species as a whole are endangered. This research project focuses on assessing the threat of inbreeding and low genetic diversity on the small, isolated population of the SLE beluga. To estimate the degree of inbreeding, as well as the loss of genetic diversity within the SLE beluga, Arctic samples from Nunavik were genotyped using multiplex PCR and capillary electrophoresis for the creation of microsatellite profiles for each individual. The microsatellite profiles of the Nunavik individuals were then compared to with those from the SLE beluga that had previously been genotyped. The effective population size (Ne) was also estimated for the SLE population.