Assessment of the South and East Hudson Bay Atlantic Walrus (Odobenus rosmarus rosmarus) Stock in 2022

Abstract

The aerial coastal photographic survey conducted in September 2022 covered all known terrestrial haul-out sites identified within the distribution range of South and East Hudson Bay (SEHB) walruses, based on previous surveys and Inuit Qaujimajatuqangit (local knowledge). Average counts of hauled out walruses from the photographic aerial survey totaled 130. The corresponding abundance estimate (rounded to the nearest 10) was 430 (95% CI = 160– 1,190) after accounting for animals at sea during the survey. Satellite images covering most of the surveyed area, taken between August and October 2022, were also analyzed to obtain a second abundance estimate. Average number of walruses hauled out estimated from satellite images was 190, corresponding to an abundance estimate of 630 (95% CI = 230–1,770) after accounting for animals at sea. The combined estimate of abundance from both the aerial survey and satellite images is 500 (95% CI = 230–1,060) walruses. Based on the combined estimate of abundance, the Potential Biological Removal (PBR) estimate for the SEHB stock is 4. The correction factor for animals at sea has a large impact on the abundance estimate but is informed by a limited amount of data.