Research Document 2024/030
Recovery Potential Assessment for Beluga (Delphinapterus leucas) Stocks in Nunavik (Northern Quebec)
By Sauvé, C., Caissy, P., Hammill, M.O., Mosnier, A., St-Pierre, A. P., and Gosselin, J.-F.
Abstract
In 2020, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assessed the eastern Hudson Bay (EHB) and Ungava Bay (UB) beluga designatable units (DUs) as Threatened and Endangered, respectively. These two DUs are currently under ministerial review for listing under the Species at Risk Act (SARA). DFO Science has been tasked to undertake a Recovery Potential Assessment (RPA) for these two DUs to help inform the listing decision and, if the listing is confirmed, the future development of recovery documents. Since the last beluga DU review by COSEWIC in 2016, a distinct genetic population has been identified in the Belcher Islands (BEL), within the EHB DU’s geographic summer distribution area. Therefore, this RPA is not specific to the EHB genetic population alone, but rather to the joint BEL-EHB stock. Beluga aggregations are observed during summer in the estuaries and along the coast of the eastern Hudson Bay arc. In the fall, beluga from this area undertake a northward seasonal migration along the Nunavik coast to reach wintering areas in Hudson Strait and along the Labrador coast. While UB beluga were historically abundant in southern Ungava Bay, no large beluga aggregation has been seen during surveys conducted over the past 40 years. However, continued sightings and occasional harvests either suggest that the Ungava Bay DU persists at a very low level, or that neighbouring DUs frequent Ungava Bay. Most recent data indicates a continuous decline in BEL-EHB beluga since the 1970s, with an abundance estimate of 2,900-3,200 beluga in 2021. Management of subsistence beluga harvest is the main challenge for BEL-EHB and UB beluga survival and recovery. Other threats from human activities in the habitat of BEL-EHB and UB beluga include anthropogenic noise, industrial development, vessel traffic, chemical pollution, commercial fisheries, and climate change. A long-term (i.e., over > 100 years) distribution objective would be to recover the historical distribution of beluga in eastern Hudson Bay estuaries and within southern Ungava Bay and its estuaries.Three recovery abundance objectives are proposed for BEL-EHB beluga: 1) attain an abundance equal to or exceeding the 2015 abundance estimate in ten years, 2) attain an abundance equal to or exceeding the Precautionary Reference Level (PRL = 5,300 individuals) in 86 years, and 3) attain an abundance corresponding to the demographic growth given no harvest from this stock. The current harvest levels are incompatible with any of these recovery targets. Two recovery targets for abundance are proposed for UB beluga: 1) maintain population size at or above the 2022 abundance estimate, and 2) attain a population size corresponding to the demographic growth given no harvest from this DU. Perpetuating current harvest levels for UB beluga would lead to population decline and extirpation of any remaining stock in this area within 4 to 21 years. The Potential Biological Removal for BEL-EHB and UB beluga was estimated at 5 and 0 whales per year, respectively based on 2022 abundance estimates. Projections indicate that it is feasible for the BEL-EHB stock to reach the PRL in 86 year with an annual harvest level of 20 beluga.
Accessibility Notice
This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.
- Date modified: